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Biomedical subjects

B Roth

Publications and source records attributed to B Roth.

At least 55 records · Page 3Linked to original sources
PubMed2000

Imidazoline receptor antisera-selected (IRAS) cDNA: cloning and characterization.

The imidazoline-1 receptor (IR1) is considered a novel target for drug discovery. Toward cloning an IR1, a truncated cDNA clone was isolated from a human hippocampal lambda gt11 cDNA expression library by relying on the selectivity of two antisera directed against candidate IR proteins. Amplification reactions were performed to extend the 5' and 3' ends of this cDNA, followed by end-to-end PCR and conventional cloning. The resultant 5131-basepair molecule, designated imidazoline receptor-antisera-selected (IRAS) cDNA, was shown to encode a 1504-amino acid protein (IRAS-1). No relation exists between the amino acid sequence of IRAS-1 and proteins known to bind imidazolines (e.g., it is not an alpha2-adrenoceptor or monoamine oxidase subtype). However, certain sequences within IRAS-1 are consistent with signaling motifs found in cytokine receptors, as previously suggested for an IR1. An acidic region in IRAS-1 having an amino acid sequence nearly identical to that of ryanodine receptors led to the demonstration that ruthenium red, a dye that binds the acidic region in ryanodine receptors, also stained IRAS-1 as a 167-kD band on SDS gels and inhibited radioligand binding of native I1 sites in untransfected PC-12 cells (a source of authentic I1 binding sites). Two epitope-selective antisera were also generated against IRAS-1, and both reacted with the same 167-kD band on Western blots. In a host-cell-specific manner, transfection of IRAS cDNA into Chinese hamster ovary cells led to high-affinity I1 binding sites by criteria of nanomolar affinity for moxonidine and rilmenidine. Thus, IRAS-1 is the first protein discovered with characteristics of an IR1.

Amino Acid Motifs↗
PubMed2000

Endpoints of resuscitation of critically injured patients: normal or supranormal? A prospective randomized trial.

OBJECTIVE: To evaluate the effect of early optimization in the survival of severely injured patients. SUMMARY BACKGROUND DATA: It is unclear whether supranormal ("optimal") hemodynamic values should serve as endpoints of resuscitation or simply as markers of the physiologic reserve of critically injured patients. The failure of optimization to produce improved survival in some randomized controlled trials may be associated with delays in starting the attempt to reach optimal goals. There are limited controlled data on trauma patients. METHODS: Seventy-five consecutive severely injured patients with shock resulting from bleeding and without major intracranial or spinal cord trauma were randomized to resuscitation, starting immediately after admission, to either normal values of systolic blood pressure, urine output, base deficit, hemoglobin, and cardiac index (control group, 35 patients) or optimal values (cardiac index >4.5 L/min/m2, ratio of transcutaneous oxygen tension to fractional inspired oxygen >200, oxygen delivery index >600 mL/min/m2, and oxygen consumption index >170 mL/min/m2; optimal group, 40 patients). Initial cardiac output monitoring was done noninvasively by bioimpedance and, subsequently, invasively by thermodilution. Crystalloids, colloids, blood, inotropes, and vasopressors were used by predetermined algorithms. RESULTS: Optimal values were reached intentionally by 70% of the optimal patients and spontaneously by 40% of the control patients. There was no difference in rates of death (15% optimal vs. 11% control), organ failure, sepsis, or the length of intensive care unit or hospital stay between the two groups. Patients from both groups who achieved optimal values had better outcomes than patients who did not. The death rate was 0% among patients who achieved optimal values compared with 30% among patients who did not. Age younger than 40 years was the only independent predictive factor of the ability to reach optimal values. CONCLUSIONS: Severely injured patients who can achieve optimal hemodynamic values are more likely to survive than those who cannot, regardless of the resuscitation technique. In this study, attempts at early optimization did not improve the outcome of the examined subgroup of severely injured patients.

Adult↗
PubMed2000

Expression profiling of the maize flavonoid pathway genes controlled by estradiol-inducible transcription factors CRC and P.

To determine the scope of gene expression controlled by the maize transcription factors C1/R and P, which are responsible for activating flavonoid synthesis, we used GeneCalling, an open-ended, gel-based, mRNA-profiling technology, to analyze cell suspension lines of the maize inbred Black Mexican Sweet (BMS) that harbored estradiol-inducible versions of these factors. BMS cells were transformed with a continually expressed estrogen receptor/maize C1 activator domain fusion gene (ER-C1) and either a fusion of C1 and R (CRC), P, or luciferase genes regulated by a promoter containing four repeats of an estrogen receptor binding site. Increasing amounts of luciferase activity, anthocyanins, and flavan-4-ols were detected in the respective cell lines after the addition of estradiol. The expression of both known and novel genes was detected simultaneously in these BMS lines by profiling the mRNA isolated from replicate samples at 0, 6, and 24 hr after estradiol treatment. Numerous cDNA fragments were identified that showed a twofold or greater difference in abundance at 6 and 24 hr than at 0 hr. The cDNA fragments from the known flavonoid genes, except chalcone isomerase (chi1), were induced in the CRC-expressing line after hormone induction, whereas only the chalcone synthase (c2) and flavanone/dihydroflavonol reductase (a1) genes were induced in the P-expressing line, as was expected. Many novel cDNA fragments were also induced or repressed by lines expressing CRC alone, P alone, or both transcription factors in unique temporal patterns. The temporal differences and the evidence of repression indicate a more diverse set of regulatory controls by CRC or P than originally expected. GeneCalling analysis was successful in detecting members of complex metabolic pathways and uncovering novel genes that were either coincidentally regulated or directly involved in such pathways.

Artificial Gene Fusion↗
PubMed2000

Intravenous formulations of the enantiomers of thalidomide: pharmacokinetic and initial pharmacodynamic characterization in man.

Thalidomide, a racemate, is coming into clinical use as an immunomodulating and antiinflammatory drug. These effects may chiefly be exerted by S-thalidomide, but the enantiomers are interconverted in-vivo. Thalidomide is given orally, although parenteral administration would be desirable in some clinical situations. The aim of this study was to prepare solutions of the enantiomers of thalidomide for intravenous administration and to investigate their pharmacokinetics and sedative effects following infusion in man. Solubility and stability of the enantiomers in 5% glucose solution was investigated. After a dose-determination experiment in one subject, six healthy male volunteers received R- and S-thalidomide separately by 1-h infusions in a randomized double-blind cross-over study. Blood was sampled over 22h and sedative effects were recorded. Blood concentrations of the enantiomers were determined by stereospecific HPLC. A four-compartment model consisting of a two-compartment model for each enantiomer, with elimination from both compartments, connected by rate constants for chiral inversion was fitted to the concentration data, while the sedative effects were correlated with the blood concentrations of R- and S-thalidomide by means of logistic regression. The enantiomers of thalidomide were chemically stable in solution for at least a week at room temperature. The infusions were well tolerated. Sedation, which was the only observed effect, was related to the blood concentration of R-thalidomide. Inter-individual variation in the disposition of the enantiomers was modest (e.g. terminal half-lives ranged between 3.9 and 5.3h). Pharmacokinetic modelling predicted that varying the infusion time of a fixed dose of S-thalidomide between 10 min and 6h would have little influence on the maximal blood concentration of formed R-thalidomide. To our knowledge this is the first time that thalidomide has been administered intravenously.

Adult↗
PubMed2000

[Acquired peeling skin syndrome in an adult].

BACKGROUND: Peeling skin syndrome is a rare form of congenital ichthyosis. The term was coined in 1982 by Levy and Goldsmith and the syndrome is clinically characterized by generalized scaling. Histologically, there is an epidermal separation in the stratum corneum. CASE REPORT: We report the case of a 73-year-old woman who had ichthyosis without cicatricial progressive alopecia since her first pregnancy. An ultrastructural study was performed confirming the clinical diagnosis of peeling skin syndrome. DISCUSSION: The peeling skin syndrome designates several different clinical entities classed by Traupe in type A and type B. Mevorah and al. expanded this classification with a type C. This classification has remained valid after additional information provided by ultrastructural studies and may suggest different pathogenic mechanisms underlying the dermatosis. A critical review of the literature shows that the case reported here is exceptional and had a late clinical onset.

Adult↗
PubMed1999

Chromosomal imbalances in noninvasive papillary bladder neoplasms (pTa).

Almost 70% of urinary bladder neoplasms present as low-grade papillary noninvasive tumors (stage pTa). To determine which genomic alterations can occur in pTa tumors of different grades and to evaluate the prognostic significance of chromosomal imbalances, we analyzed 113 pTa tumors (40 grade 1, 55 grade 2, 18 grade 3) by comparative genomic hybridization. pTaG1 (1.9 +/- 2.0) and pTaG2 (3.1 +/- 2.9) tumors had only few genomic alterations with 9q- (44%), 9p- (36%), and -Y (21%) being most prevalent. Neither the total number of aberrations nor any individual alteration was linked to the risk of recurrence in 95 pTaG1/G2 tumors with clinical follow-up information. pTaG3 tumors were characterized by a high number of alterations (7.7 +/- 4.5; P < 0.0001 for G3 versus G2). Several chromosomal imbalances that have previously been reported to be typical for invasive bladder neoplasms were significantly more frequent in pTaG3 than in pTaG2 tumors, including 2q-, 5p+, 5q-, 6q-, 8p-, 10q-, 18q-, and 20q+. A malfunction of genes at these loci may contribute to the development of high-grade urothelial neoplasias. However, there is no evidence for a direct role of these alterations for development of invasive tumor growth.

Carcinoma in Situ↗
PubMed1999

Right sternoclavicular dislocation after traumatic delivery: a case report.

Sternoclavicular (SC) dislocation is an injury that is very rare in the newborn. Thus far there have been no reports describing this in neonates after a traumatic birth injury. This condition can be difficult to differentiate from epiphyseal separation, which occurs more often in older children. For successful treatment, early diagnosis is essential. Timely surgical reposition and fixation with following immobilization is recommended in instances of complete (SC) dislocation. We report a trauma-induced case of SC dislocation in a neonate successfully managed by polydioxanon cord fixation.

Birth Injuries↗
PubMed1999

Management of acute inflammatory childhood stridor.

BACKGROUND AND OBJECTIVE: Acute epiglottitis, bacterial tracheitis, and severe viral laryngotracheobronchitis continue to cause life-threatening airway obstruction in children. The aim of this retrospective study was to evaluate deficiencies in treatment, to clarify the role of airway endoscopy, and to identify current reasons for fatalities in these diseases. MATERIALS AND PATIENTS: During the observation period from 1980 to 1996, we identified 61 patients treated in the pediatric intensive care unit of the University Hospital of Cologne for severe inflammatory airway obstruction. RESULTS: Critical points in the appropriate airway management were (1) the confirmation of the admission diagnosis, (2) whether an artificial airway or rigid tracheobronchoscopy was required; and (3) appropriate timing of extubation. Since 1989 airway evaluation with flexible or small, rigid endoscopes was used to confirm the diagnosis and to determine the appropriate management. Endoscopic findings were extremely helpful to decide not to intubate and to monitor in the pediatric intensive care unit first. Three patients with acute epiglottitis died after out-of-hospital cardiorespiratory arrest. CONCLUSION: Endoscopy should be a part of every established treatment protocol of childhood stridor. The most decisive factor to decrease mortality seems to be timely presentation to a referral center.

Airway Obstruction↗
PubMed1999

Early metabolic acidosis and coma after acetaminophen ingestion.

Metabolic acidosis and coma may develop in patients who experience severe hepatic injury after acetaminophen poisoning. The onset of acidosis and coma soon after acetaminophen overdose, but preceding manifest hepatic injury, contrasts with the typical course of poisoning. This pattern has been reported in a limited number of cases. Coingestions and the rare occurrence of these findings after an overdose have engendered controversy as to whether acetaminophen alone is the cause of early coma and acidosis. We describe 4 separate overdoses among 3 patients who arrived at the emergency department comatose with a metabolic acidosis soon after ingesting large amounts of acetaminophen without evidence of toxic liver injury. Our cases support the view that early metabolic acidosis with coma does indeed occur after acetaminophen poisoning, independent of hepatic failure or its complications.

Acetaminophen↗
PubMed1999

Characterization of radioactive metabolites of 5-HT2A receptor PET ligand [18F]altanserin in human and rodent.

This study was performed to identify and characterize the radiometabolites of the serotonin 5-HT2A receptor ligand [18F]altanserin in supporting quantification of the target receptors by positron emission tomography. In analogy to its analog ketanserin, we postulated 4-(4-fluorobenzoyl)piperidine (FBP) and altanserinol for the previously observed two polar radiometabolites, corresponding to dealkylation at the piperidine nitrogen and reduction at the ketone, respectively. To test this hypothesis and characterize the in vivo and in vitro behavior of the radiometabolites, we synthesized nonradioactive authentic compounds altanserinol, 1-(4-fluorophenyl)-1-(piperidin-4-yl)methanol (FBPOH), and isolated nonradioactive FBP metabolite from monkey plasma. [18F]Altanserinol was obtained by NaBH4 reduction of [18F]altanserin, followed by acid hydrolysis. Identification of radiometabolites was carried out by high performance liquid chromatography and thin layer chromatography comparison of the radioactive plasma after injection of tracers with five authentic compounds. Human studies revealed that at least four radiometabolites, one identified as [18F]altanserinol, resulted from reduction of the ketone functionality. The N-dealkylation product [18F]FBP was not detectable; however, a radiometabolite of FBP was present in plasma after administration of [18F]altanserin. Monkey studies showed nonradioactive FBP was converted rapidly to a less polar metabolite. In rat, altanserin and altanserinol were converted to each other in vivo, and all the radiometabolites likely penetrated the blood-brain barrier and entered the brain. Displacement binding of altanserin to cloned serotonin 5-HT2A, 5-HT2C, 5-HT6, and 5-HT7 receptors showed Ki values of 0.3, 6.0, 1,756, and 15 nM; the binding of FBP and altanserinol to these four 5-HT subtypes was negligible. We conclude from these studies that the radiometabolites of [18F]altanserin from N-dealkylation and ketone reduction should not interfere with specific receptor quantification in an equilibrium paradigm.

Animals↗
PubMed1999

Vinblastine versus vinblastine plus oral estramustine phosphate for patients with hormone-refractory prostate cancer: A Hoosier Oncology Group and Fox Chase Network phase III trial.

PURPOSE: To compare vinblastine versus the combination of vinblastine plus estramustine as treatment for patients with hormone-refractory prostate cancer (HRPC). PATIENTS AND METHODS: A total of 201 patients with metastatic prostate cancer, progressive after hormonal therapy and antiandrogen withdrawal (if prior antiandrogen treatment), were randomized to receive vinblastine (V) 4 mg/m(2) by intravenous bolus weekly for 6 weeks followed by 2 weeks off, either alone or together with estramustine phosphate (EM-V) 600 mg/m(2) PO days 1 through 42, repeated every 8 weeks. Of 193 eligible patients, 98 received V, and 95 received EM-V. RESULTS: Overall survival trended in favor of EM-V but was not significantly different as determined by Kaplan-Meier analysis (P =.08). Median survival was 11.9 months for EM-V and 9.2 months for V. EM-V was superior to V for secondary end points of time to progression (P <. 001, stratified log rank test; median 3.7 v 2.2 months, respectively) and for proportion of patients with >/= 50% prostate-specific antigen (PSA) decline sustained for at least 3 monthly measurements (25.2% v 3.2%, respectively; P <.0001). Granulocytopenia was significantly less for EM-V compared with V (grade 2, 3, and 4 = 7%, 7%, and 1% v 27%, 18% and 9%, respectively; P <.0001); however, grade 2 or worse nausea (26% v 7%, respectively; P =.0002) and extremity edema (22% v 8%, respectively; P =.005) were more frequent for EM-V. CONCLUSION: Although overall survival was not significantly greater for the combination, EM-V was superior to V for time to progression and PSA improvement. These results encourage further study of estramustine-based antimicrotubule drug combinations in HRPC.

Administration, Oral↗
PubMed1999

Eligibility and response guidelines for phase II clinical trials in androgen-independent prostate cancer: recommendations from the Prostate-Specific Antigen Working Group.

PURPOSE: Prostate-specific antigen (PSA) is a glycoprotein that is found almost exclusively in normal and neoplastic prostate cells. For patients with metastatic disease, changes in PSA will often antedate changes in bone scan. Furthermore, many but not all investigators have observed an association between a decline in PSA levels of 50% or greater and survival. Since the majority of phase II clinical trials for patients with androgen-independent prostate cancer (AIPC) have used PSA as a marker, we believed it was important for investigators to agree on definitions and values for a minimum set of parameters for eligibility and PSA declines and to develop a common approach to outcome analysis and reporting. We held a consensus conference with 26 leading investigators in the field of AIPC to define these parameters. RESULT: We defined four patient groups: (1) progressive measurable disease, (2) progressive bone metastasis, (3) stable metastases and a rising PSA, and (4) rising PSA and no other evidence of metastatic disease. The purpose of determining the number of patients whose PSA level drops in a phase II trial of AIPC is to guide the selection of agents for further testing and phase III trials. We propose that investigators report at a minimum a PSA decline of at least 50% and this must be confirmed by a second PSA value 4 or more weeks later. Patients may not demonstrate clinical or radiographic evidence of disease progression during this time period. Some investigators may want to report additional measures of PSA changes (ie, 75% decline, 90% decline). Response duration and the time to PSA progression may also be important clinical end point. CONCLUSION: Through this consensus conference, we believe we have developed practical guidelines for using PSA as a measurement of outcome. Furthermore, the use of common standards is important as we determine which agents should progress to randomized trials which will use survival as an end point.

Androgens↗
PubMed1999

Scrofuloderma of the lower extremity treated with wide resection: a case report and review of the literature.

Scrofuloderma is tuberculosis of subcutaneous tissue that ulcerates and drains through the overlying skin. It most commonly occurs in the neck from a cervical lymph node source. Although such lymphatic spread is the usual clinical picture, there are sporadic reports in the literature of direct hematogenous seeding of subcutaneous tissue forming a tuberculoma, or "cold abscess." Definitive diagnosis requires the identification of Mycobacterium tuberculosis within the suspect lesion. Surgical intervention is necessary in any draining lesion and should be accompanied by appropriate antituberculous chemotherapy. Accounts of bone and joint involvement are numerous, but the orthopedic surgeon must also be aware of the soft-tissue manifestations of tuberculosis and the indications for surgery. We report on an immunocompromised patient who presented with a rare case of scrofuloderma of the lower extremity, which was treated with wide resection.

Adult↗
PubMed1998

Attenuated hematopoietic response to granulocyte-macrophage colony-stimulating factor in patients with acquired pulmonary alveolar proteinosis.

The pathogenesis of acquired pulmonary alveolar proteinosis (PAP), a rare lung disease characterized by excessive surfactant accumulation within the alveolar space, remains obscure. Gene-targeted mice lacking the hematopoietic growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF) or the signal-transducing beta-common chain of the GM-CSF receptor have impaired surfactant clearance and pulmonary pathology resembling human PAP. We therefore investigated the hematopoietic effects of GM-CSF in patients with PAP. The hematologic response of 5 infants with congenital PAP to 5 microgram/kg/d was of normal magnitude. By contrast, despite normal expression of GM-CSF receptor alpha- and beta-common chains on peripheral blood myelomonocytic cells (n = 6) and normal binding affinity of bone marrow mononuclear cells for GM-CSF (n = 3), each of the 12 patients with acquired PAP treated displayed impaired responses to GM-CSF; 5 microgram/kg/d produced only minor eosinophilia, and doses of 7.5 to 20 microgram/kg were required to induce >/=1.5-fold neutrophil increments in the 3 patients who underwent dose-escalation. However, neutrophilic responses to 5 microgram/kg granulocyte colony-stimulating factor (G-CSF) were normal (n = 4). In vitro, the proportion of hematopoietic progenitors responsive to GM-CSF (16.1% +/- 8.9%; P = .042) or interleukin-3 (IL-3; 19.3% +/- 7.7%; P = .063), both of which utilize the beta-common chain of the GM-CSF receptor complex, were reduced among patients with acquired PAP (n = 4) compared with normal bone marrow donor controls (47.2% +/- 25.9% and 40.9% +/- 18.6%, respectively). In the one individual who had complete resolution of lung disease during the period of study, this was temporally associated with correction of this defective in vitro response to GM-CSF and IL-3 on serial assessment. These data establish that patients with acquired PAP have an associated impaired responsiveness to GM-CSF that is potentially pathogenic in the development of their lung disease. Based on these observations, we propose a model of the pathogenesis of acquired PAP that suggests the disease arises as a consequence of an acquired clonal disorder within the hematopoietic progenitor cell compartment.

Adolescent↗
PubMed1998

Epidemiology and etiology of acquired hearing disorders in childhood in the Cologne area.

Because of their serious consequences for all aspects of development, severe hearing disorders in children are an important clinical entity. A better understanding of the epidemiology and etiology of acquired hearing disorders may potentially lead to more effective prevention. Marked differences in the epidemiology of acquired hearing disorders are reported in the literature. In order to illuminate the problem of acquired disorders and to define current etiological causes with special regard to ethnological factors in the Cologne area, we started a retrospective study. A total of 314 children in residence at the school for hearing impaired children in Cologne were investigated. We also obtained concise data on the structure of the population in order to determine prevalence of acquired hearing disorders in the German and immigrant portions of the population. We found an overall prevalence of 0.43 per thousand for severe hearing disorders and deafness. German children were most frequently affected by acquired, and non-German children by hereditary hearing disorders. The most common causes of acquired severe hearing disorder were the perinatal complex of premature delivery, anoxia and hyperbilirubinuria or kernicterus. Other causes were congenital rubella infections and meningitis in early childhood. The accumulation of perinatal etiologies seems to be the reason for the remarkable majority of acquired hearing disorders among German children. One reason might be progress in neonatology which exerts two effects. It decreases perinatal mortality but increases perinatal complications like acquired hearing impairment. The incidence of congenital rubella in Germany has decreased during recent years, reaching a low level.

Child↗