Biomedical subjects

J Schreiber

Publications and source records attributed to J Schreiber.

At least 19 recordsLinked to original sources

PubMed2004

Influence of the laser prepulse on proton acceleration in thin-foil experiments.

We investigate the influence of the laser prepulse due to amplified spontaneous emission on the acceleration of protons in thin-foil experiments. We show that changing the prepulse duration has a profound effect on the maximum proton energy. We find an optimal value for the target thickness, which strongly depends on the prepulse duration. At this optimal thickness, the rear side acceleration process leads to the highest proton energies, while this mechanism is rendered ineffective for thinner targets due to a prepulse-induced plasma formation at the rear side. In this case, the protons are primarily accelerated by the front side mechanism leading to lower cutoff energies.

Journal Article↗

PubMed2002

Mycobacterium tuberculosis gene-amplification in breath condensate of patients with lung tuberculosis.

The applicability of Mycobacterium tuberculosis-gene-amplification test (NAT) in breath condensate (BC) was examined in lung tuberculosis (TB). Ten patients with bacteriologically confirmed lung TB have been examined by ligase chain reaction (LCx). In BC the NAT were negative in all patients as well as the examination of acid fast smears and of solid phase or liquid media cultures were. This indicates that the use of NAT in BC can not replace or complement sputum or materials obtained invasively in patients with lung TB.

Adult↗

PubMed2002

Microwave single walled carbon nanotubes purification.

A new single walled carbon nanotubes (SWCNTs) purification procedure has been developed; it consists in a combination of air treatment and acid microwave digestion leading to a high purity SWCNTs material; the procedure reaches high metal removal percentages and the operation time is drastically reduced compared to conventional acid reflux treatments.

Journal Article↗

PubMed2002

Influence of mucolytic therapy on respiratory mechanics in patients with chronic obstructive pulmonary disease.

Mucus hypersecretion is a hallmark of chronic obstructive pulmonary disease (COPD) and is regarded as contributing to airflow limitation in these patients. The value of mucolytic therapy is still a matter for debate. We investigated the short-term influence of an inhalative mucolytic drug mercapto-ethane sulfonate (Mesna) on the lung function, respiratory mechanics and viscous respiratory load in patients with COPD in a randomized, placebo controlled, double-blind, cross-over study in 10 patients with moderate, stable COPD. Resistance, static compliance and frequency dependent dynamic compliance and viscous respiratory work, FVC, FEV(1), PEFR, MEF(75), MEF(50), MEF(25), TLC and RV were measured. These lung function parameters did not show any significant differences between the treatment groups. In conclusion, an inhalative treatment with an active mucolytic drug of patients with mild COPD does not improve respiratory mechanics and respiratory load.

Administration, Inhalation↗

PubMed2002

[Umbilical metastasis of a gallbladder carcinoma: "Sister Mary Joseph's nodule"].

UNLABELLED: HISTOLOGY AND CLINICAL FINDINGS: A 63-year-old man presented with a firm and crusting umbilical mass which had developed within several weeks. The tumor was 1.5 cm in diameter. There were no other diseases in the patient's history. Physical examination was normal except the umbilical tumor. INVESTIGATIONS: Histologic examination revealed a malignant epithelial tumor corresponding to a metastasis of an adenocarcinoma which could be a carcinoma of the gallbladder or the pancreas. Initially the following clinical examination of the patient showed no pathological findings: gastroscopy and coloscopy gave no hint for a primary carcinoma. Computed tomography of the abdomen revealed a thickened gallbladder wall with an irregular intraluminal contour suspicious of a gallbladder carcinoma. During surgery the gallbladder showed a clearly thickened wall. There were numerous carcinomatous lesions on the peritoneum. A cholecystectomy was performed and the umbilical metastasis was excised. DIAGNOSIS, TREATMENT AND COURSE: Histologic examination revealed a metastatic adenocarcinoma of the gallbladder with tumorous infiltration of the liver tissue and a solitary metastasis in the skin (>>Sister Mary Joseph's nodule<<). During wound healing there were no complications and the patient was demitted 10 days after surgery. Following a recovery phase at home a palliative chemotherapy was planned. Because the patient's general condition worsened he was readmitted to the hospital. He presented with a considerable anemia and an icterus. Sonography revealed a hilar tumor measuring 4 cm in diameter. The intrahepatic bile ducts were congested. A stent was inserted by endoscopic retrograde pancreaticocholangiography. During the following weeks the patient's general condition worsened rapidly and he died 9 months after the skin metastasis had occurred. CONCLUSION: A rapidly developing umbilical mass (>>Sister Mary Joseph's nodule<<) is suspicious of an underlying metastatic adenocarcinoma. The necessary examination and therapy including excision of the umbilical metastasis is warranted without delay.

Adenocarcinoma↗

PubMed2002

[Paraneoplastic pityriasis rubra pilaris in metastatic adenocarcinoma without diagnosable primary].

HISTORY AND ADMISSION FINDINGS: A 75-year-old woman, without a history of severe illness, developed an erythematosquamous skin disease on hands and forearms. After continued spreading of these cutaneous lesions, she was admitted to hospital, presenting with a generalised desquamating erythrodermia and marked pruritus. INVESTIGATIONS: Skin biopsy showed cornocutaneous signs with alternating ortho- and parakeratosis, typical for pityriasis rubra pilaris. Laboratory findings showed a chronic to acute inflammation with leukocytosis, granulocytosis in the differential blood count, raised C-reactive protein in a range from 54.7 to a maximum of 157.2 mg/l and a protein electrophoresis with elevated alpha1- and alpha2-fraction. TREATMENT AND COURSE: The erythrodermia only temporarily receded under systemic therapy with acitretin and prednisolone. The patient developed intermittent septic fever accompanied by reduction or loss of consciousness. The general condition of the patient worsened considerably. Out of a rapidly progressing pleural effusion malignant cells similar to adenocarcinoma were isolated. Because CA15-3 was elevated we conducted an extended search especially for a breast carcinoma, but found only pathologically enlarged axillary, mediastinal and abdominal lymph nodes in conventional X-ray, CT, ultrasound and endoscopic procedures. The patient died from paraneoplastic pulmonary embolism. At autopsy, the widespread metastatic dissemination from poorly differentiated adenocarcinoma was confirmed. A necrosis in the right breast containing tumour cell remnants could probably be regarded as the primary neoplasm. Immunohistochemically no definite proof of breast nor gastro-intestinal carcinoma could be found. CONCLUSIONS: This case presents a rare paraneoplastic cutaneous manifestation as pityriasis rubra pilaris triggered by a poorly differentiated adenocarcinoma. The primary neoplasm could not definitely be identified, neither pre nor post mortem.

Acitretin↗

PubMed2002

[Precurarization of succinylcholine with cisatracurium: the influence of the precurarization interval].

PURPOSE: To determine the influence of two different pretreatment intervals, i.e. 3 and 6 min, on the efficacy of 0.01 mg/kg cisatracurium in preventing succinylcholine-induced fasciculations and myalgia. METHODS: A total of 60 adult patients were randomized and received either 0.01 mg/kg cisatracurium (0.2*ED(95)) i.v. (Cis 3 group: pretreatment interval 3 min, Cis 6 group: pretreatment interval 6 min) or normal saline i.v. (placebo group) prior to injection of succinylcholine. The incidence and severity of fasciculations and myalgia and side-effects of precurarization were assessed. RESULTS: The incidence of muscle fasciculations was only reduced in the Cis 6 group (45%) compared with the Placebo group (85%), p<0.05. Cisatracurium was associated with a higher incidence of paralytic symptoms in both pretreatment groups (Cis 3: 75%, Cis 6: 80%) compared with the Placebo group (30%), p<0.05. CONCLUSION: Cisatracurium is only effective in preventing succinylcholine-induced fasciculations when a longer pretreatment interval, i.e. 6 min instead of 3 min, is chosen. Precurarization led to signs of paralysis in both pretreatment groups in the majority (75-80%) of patients without reducing the incidence or severity of postoperative myalgia.

Adult↗

PubMed2001

Interstitial lung disease induced by endogenous Candida albicans.

We report on a 64-year old woman with an interstitial lung disease which had characteristics of hypersensitivity pneumonitis. Severe febrile attacks with impairment of ventilation and diffuse poorly defined radiodensities and ground glass opacities on chest x-ray occured repeatedly. Laboratory data showed hypoxemia, leukopenia and circulating Candida albicans (C.a.)-antigen. Bronchoalveolar lavage revealed an increase in neutrophils. Transbronchial biopsies showed lymphocytic alveolitis, bronchiolitis obliterans and epitheloid cell granulomas. IgG and IgA and the lymphocyte proliferation assay were positive with C.a.-antigen. C.a. was detected in the feces. Intradermal skin test with C.a. showed a positive immediate and late phase reaction and inhalative provocation test with C.a.-antigen was positive. After antimycotic treatment the symptoms resolved completely and long-lasting. We conclude that the disease was induced by C.a.-antigen reaching the lungs from the intestinal tract via the bloodstream.

Antifungal Agents↗

PubMed2001

Reproducibility of HTS-SQUID magnetocardiography in an unshielded clinical environment.

A new technology has been developed which measures the magnetic field of the human heart (magnetocardiogram, MCG) by using high temperature superconducting (HTS) sensors. These sensors can be operated at the temperature of liquid nitrogen without electromagnetic shielding. We tested the reproducibility of HTS-MCG measurements in healthy volunteers. Unshielded HTS-MCG measurements were performed in 18 healthy volunteers in left precordial position in two separate sessions in a clinical environment. The heart cycles of 10 min were averaged, smoothed, the baselines were adjusted, and the data were standardized to the respective areas under the curves (AUC) of the absolute values of the QRST amplitudes. The QRS complexes and the ST-T intervals were used to assess the reproducibility of the two measurements. Ratios (R(QRS), R(STT)) were calculated by dividing the AUC of the first measurement by the ones of the second measurement. The linear correlation coefficients (CORR(QRS), CORR(STT)) of the time intervals of the two measurements were calculated, too. The HTS-MCG signal was completely concealed by the high noise level in the raw data. The averaging and smoothing algorithms unmasked the QRS complex and the ST segment. A high reproducibility was found for the QRS complex (R(QRS)=1.2+/-0.3, CORR(QRS)=0.96+/-0.06). Similarly to the shape of the ECG it was characterized by three bends, the Q, R, and S waves. In the ST-T interval, the reproducibility was considerably lower (R(STT)=0.9+/-0.2, CORR(STT)=0.66+/-0.28). In contrast to the shape of the ECG, a baseline deflection after the T wave which may belong to U wave activity was found in a number of volunteers. HTS-MCG devices can be operated in a clinical environment without shielding. Whereas the reproducibility was found to be high for the depolarization interval, it was considerably lower for the ST segment and for the T wave. Therefore, before clinically applying HTS-MCG systems to the detection of repolarization abnormalities in acute coronary syndromes, further technical development of the systems is necessary to improve the signal-to-noise ratio.

Adult↗

PubMed2001

Differential mediator release from basophils of allergic and non-allergic asthmatic patients after stimulation with anti-IgE and C5a.

The differentiation between allergic and non-allergic asthma is a common and important challenge for the clinician. Until now, no in vitro diagnostic characteristics have been described to distinguish between these types. To examine the diagnostic value of a basophil stimulation test, we compared anti-IgE- and C5a-induced mediator release from peripheral blood leucocytes in different types of bronchial asthma. Peripheral blood leucocytes (PBL) from 10 aspirin-sensitive asthmatics (ASA), 12 non-allergic asthmatics without aspirin intolerance (NAA), seven allergic asthmatics (AA), and nine healthy controls were prepared by dextran sedimentation. After priming with interleukin-3 (IL-3) PBL were stimulated with anti-IgE and C5a, and the release of histamine (HR) and sulfidoleukotrienes (LTR) in the supernatant was compared. Additionally, purified leucocyte fractions were studied to determine the cellular source of mediator release. Upon stimulation with anti-IgE LTR was slightly, but not significantly, lower in ASA and NAA compared to AA and controls. In contrast, C5a-triggered LTR was significantly higher in ASA (14.4 +/- 12.88 pg/105 cells) and NAA (22.9 +/- 22.61 pg/105 cells) than in AA (9.6 +/- 3.29 pg/105 cells) and controls (7.5 +/- 7.19 pg/105 cells) (P < 0.05). This difference between ASA and NAA vs. AA and controls was even more pronounced when determining the quotient C5a-/anti-IgE-induced LTR (P < 0.001). At an optimal cut-off point of 1.0, calculated by relative operating characteristics (ROC) analysis, the positive predictive value for a donor to belong to ASA or NAA was 0.94. No significant differences could be found in HR between the asthmatic patient groups and healthy controls in either condition. As cellular source of LTR and HR the basophil could be determined. Determination of anti-IgE- and C5a-induced LTR from basophils allows us to discriminate between allergic and non-allergic asthmatic patients. For diagnostic purposes the quotient C5a-/anti-IgE-induced LTR is more significant than considering a single parameter. ASA cannot be distinguished from NAA.

Adolescent↗

PubMed2001

[Non-tubercular mycobacterial infection of the lungs due to Mycobacterium smegmatis].

Nontuberculous mycobacteriosis due to M. smegmatis is a rarity. We report on the case of a 51 year old male HIV-seronegative patient without predisposing bronchopulmonary disease, but with a state after gastrectomy and splenectomy who developed unproductive cough, night sweat and weight loss. The chest radiograph and thoracic CT showed wide-spread bilateral patchy infiltrations. Histological examination of transbronchial biopsies revealed chronic carnificating pneumonia. A perhoracic fine-needle biopsy showed caseating epitheloid cell granulomas with acid fast bacilli. These were identified as M. smegmatis by PCR with subsequent sequencing. Acid fast bacilli could not be detected microscopically neither in sputum nor in bronchial secretions, however M. smegmatis has been repeatedly detected by culture in these materials. In neither material tubercle bacilli have been detected by nucleic acid amplification (NAT) or culture. Immunologic investigations revealed a reduced number of CD4+ lymphocytes and a reduction of interferon alpha- and -gamma-synthesis by peripheral blood mononuclear cells. Treatment with Rifabutin, Ethambutol, Clarithromycin and Ofloxacin resulted in complete clinical and roentgenological resolution.

CD4-Positive T-Lymphocytes↗

PubMed2001

[Primary pulmonary manifestation of extramedullary acute myelocytic leukemia].

We report on a 49 year old female with primary extra-medullary manifestation of a acute myeloid leukemia in the lungs without leukemic signs. The disease was diagnosed by detection of leukemic blast cells in bronchoalveolar lavage. Chemotherapy with the TAD-VP-scheme resulted in partial remission. The patient died in systemic early relapse. To our knowledge this is the first description of primary isolated extra-medullary manifestation of a acute myeloid leukemia in the lungs.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2001

Temporal characteristics of slot machine play in recreational gamblers.

The present study examined the temporal characteristics of play exhibited by recreational slot machine players. 12 women (M = 24 yr., range 22-28) played a computerized version of a slot machine with probability of payoff, i.e., a winning spin, ranging from .2 to .6. Intertrial intervals or the time between the termination of one trial to the initiation of the next trial varied within subjects as a function of wins and losses. Winning trials were associated with larger intertrial intervals and losing trials with smaller intertrial intervals for 10 of the 12 women. No differences were found across probability levels between subjects. Results are discussed in terms of the post-reinforcement pause that occurs on specific schedules of reinforcement.

Adult↗

PubMed2000

Genome-wide location and function of DNA binding proteins.

Understanding how DNA binding proteins control global gene expression and chromosomal maintenance requires knowledge of the chromosomal locations at which these proteins function in vivo. We developed a microarray method that reveals the genome-wide location of DNA-bound proteins and used this method to monitor binding of gene-specific transcription activators in yeast. A combination of location and expression profiles was used to identify genes whose expression is directly controlled by Gal4 and Ste12 as cells respond to changes in carbon source and mating pheromone, respectively. The results identify pathways that are coordinately regulated by each of the two activators and reveal previously unknown functions for Gal4 and Ste12. Genome-wide location analysis will facilitate investigation of gene regulatory networks, gene function, and genome maintenance.

Binding Sites↗

PubMed2000

Hypersensitivity alveolitis induced by endogenous candida species

We report the case of a 64-year old woman with severe attacks of allergic alveolitis occurring frequently independent of a concrete place. These attacks were regularely preceded by diarrhoe. Laboratory data showed marked leukopenia and circulating Candida albicans (C.a.)-antigen. Bronchoalveolar lavage revealed an increase in neutrophils (13%). Transbronchial biopsies showed focal alveolitis and focal septal fibrosis with bronchiolitis obliterans and an epitheloid cell granuloma. Immunohistochemical examination revealed C.a.-antigen in alveolar macrophages. In the faeces a high amount of C.a. and C. glabrata was detected. In serum IgG and IgA were positive against C.a., IgE against C.a. was negative. Lymphocyte proliferation assay with C.a.-antigen was positive. Intradermal skin test with C.a. showed positive immediate and late phase reaction. Furthermore inhalation challenge with C.a.-antigen was positive. A febrile reaction with chills, dyspnea and hypoxemia and leukocytosis in peripheral blood occured after 6 hours. Lung function showed a predominantly obstructive impairment of ventilation. An extensive search for other IgG- or IgE-mediated allergies (other fungi, environmental or food allergens) was completely negative. Investigation of the gastrointestinal tract did not show any abnormality exept the detection of lactose intolerance. There was no fungal growth in the patients flat. After initiation of antimycotic treatment the symptoms resolved completely. - We conclude that the disease was induced by C.a.-antigen reaching the lungs from the intestinal tract via the bloodstream. It is still a matter of debate whether an additional factor is necessary for the antigen to penetrate the intestinal mucosa.

Journal Article↗

PubMed2000

Protein stability and domain topology determine the transcriptional activity of the mammalian glial cells missing homolog, GCMb.

The glial cells missing (GCM) family of transcription factors consists of Drosophila GCM and the mammalian proteins GCMa and GCMb. They are expressed in a highly restricted manner during development and are known or assumed to be important regulators of developmental fate decisions. As the biochemical properties of GCMb have not been studied so far, we have undertaken a detailed structure-function analysis of the mouse GCMb (mGCMb) protein. DNA-binding specificity was very similar to that of other GCM proteins. Nevertheless, mGCMb was only a weak transcriptional activator in a number of different tissue culture systems. Interestingly, this was not due to an intrinsic absence of transactivation potential. In effect, we were able to identify two separate transactivation domains within mGCMb, one carboxyl-terminally adjacent to the DNA-binding domain and the second within the extreme carboxyl terminus. Activity of both transactivation domains was, however, modulated by an inhibitory region unique to mGCMb and located between the two transactivation domains. Furthermore, pulse-chase experiments proved that the mGCMb protein has a half-life approximately four times shorter than mGCMa. Introduction of the above mentioned inhibitory domain of mGCMb into mGCMa shortened the half-life of mGCMa to a value typical of mGCMb with a concomitant reduction in transactivation potential. Given the strong correlation between protein stability and transactivation potential, functional differences between the two mammalian GCM homologs are likely due to differences in stability with a single inhibitory region in mGCMb being involved in the reduction of both.

Amino Acid Sequence↗

PubMed2000

[Studies on the stabilization of the cornea in rabbits].

BACKGROUND: The mechanical stabilization of the cornea in keratoconus may delay progression of this disease. The cross-linking techniques optimized in corneas of enucleated porcine eyes were investigated under in vivo conditions in rabbits to estimate the biocompatibility and duration of the stiffening effect. METHODS: Twenty-eight rabbits were treated monocularly, the fellow eye serving as control. The epithelium was mechanically removed and 19 eyes were treated with riboflavin plus ultraviolet irradiation (365 nm, 2 mW/cm2) for 45 min and 9 eyes with 0.075% glutaraldehyde for 20 min. After treatment, the eyelids were sutured for 3 days. The healing process was controlled by slit-lamp examination and photographically documented. After 1 month, 20 animals and after 3 months 8 animals were sacrificed, the eyes enucleated, and the stress-strain relation of the corneas measured and compared to the fellow eye. RESULTS: The epithelium was closed after 4-5 days. The transparency of the corneas remained clear during follow-up, and there were no signs of inflammatory reaction. Stress for a strain of 6% was higher in the treated corneas by a factor of 1.3 +/- 0.66 (P = 0.319) in the glutaraldehyde group and by a factor of 1.6 +/- 0.75 (P = 0.0408) in the riboflavin group at 1 month, and by 1.3 +/- 0.48 (P = 0.07) at 3 months after treatment. CONCLUSIONS: The cross-linking technique using riboflavin plus UV irradiation is suitable for at least temporarily stiffening the cornea in vivo and seems to be a promising method for conservative treatment of keratectasia.

Animals↗

PubMed2000

A chart review of the ordering and documentation of urine toxicology screens in a cancer center: do they influence patient management?

Urine toxicology screens (UTSs) may be useful in the diagnosis or monitoring of patients with established or suspected substance abuse. In the medically ill, including those with cancer, the test may help clinicians manage therapy with controlled prescription drugs. To describe the current use of UTSs in a cancer center, the medical records of 111 patients who underwent UTS were reviewed. These 111 patients were randomly selected from a group of 215 patients who underwent screening between January 1, 1990 and December 31, 1994 (a period during which over 80,000 admissions occurred). Fifty-six of the 111 patients had evidence of one or more illicit drugs, a prescription medication that had not been ordered, or alcohol; 50 patients had negative screens. The likelihood of a positive UTS was higher if the patient had human immunodeficiency virus (HIV) infection (100% versus 46.6%) or was undergoing treatment for chronic nonmalignant pain (100% versus 43.9%). Documentation of the UTS in the medical record was infrequent: 37.8% of the charts listed no reason for obtaining the test and the ordering physician could not be identified in 29% of the records. Eighty-nine percent of the records did not contain a subsequent mention of the result of the UTS. The result was more likely to lead to a documented outcome when it was positive rather than negative (14.3% versus 0%). These results suggest that UTSs are used infrequently in the tertiary care oncology center. The documentation surrounding the ordering and subsequent use of the test in patient management is unsystematic. The appropriate use and documentation of UTSs, like substance abuse issues in general, should be a focus of staff education and quality improvement efforts.

Adult↗