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A Wirth

Publications and source records attributed to A Wirth.

At least 37 records · Page 2Linked to original sources
PubMed2000

Pattern of disconfirming information and processing instructions as determinants of stereotype change.

This experiment examined the effects of pattern of disconfirming information (concentrated vs. dispersed) and processing instructions (focus on similarities vs. differences vs. control) on stereotype change. If subtyping and perceived typicality are central to the stereotype change process, then processing instructions designed to affect these processes should affect stereotyping. There was lower stereotyping when perceivers focused on similarities between group members, and after exposure to a dispersed pattern of disconfirming information. Only the main effect of pattern was mediated by the perceived typicality of disconfirmers, but not by an index of subtyping based on clustering of information from disconfirmers in recall. Results support a model of stereotype change in terms of the impact of disconfirming group members who are also seen as typical of the group; subtyping of extreme disconfirmers may work in parallel, or later, and contribute to the long-term maintenance of a stereotype.

Adult↗
PubMed1999

Expression, purification, and characterization of the cytoplasmic domain of the human IGF-1 receptor using a baculovirus expression system.

The cytoplasmatic domain of the beta-subunit of the human IGF-1 receptor (residues 929-1337) has been overexpressed in insect cells using the baculovirus expression system. Synthesis of the soluble protein (IGFK, M(r) 46 kDa) in Spodoptera frugiperda (Sf9) cells was detected 24 h after infection and maximal accumulation was achieved 40-48 h postinfection. Rapid purification to near homogeneity (>/=95% pure protein) was accomplished by sequential chromatography on Resource-Q and phenyl-Sepharose with a specific activity of 142 nmol/min/mg using poly[Glu:Tyr] as substrate. The purified IGFK showed a preference for Mn(2+) ions and a linear incorporation of (32)P from [gamma-(32)P]ATP over a 20-fold dilution of the protein and was stimulated 20-fold by the polycation poly-L-lysine. Interestingly, the kinase autophosphorylated on tyrosine and serine residues. In contrast, a kinase-negative mutant, IGFK-K1003A, did not undergo phosphorylation on tyrosine or serine residues, respectively, suggesting that IGF-1 receptor kinase is a dual specific kinase.

Adenosine Triphosphate↗
PubMed1999

System analysis of patient management during the pre- and early clinical phase in severe head injury.

Head injury with or without polytrauma is the most important cause of death and severe morbidity in an age bracket of up to 45 years. Two major factors are determining its outcome, the extent and nature of the primary irreversible brain injury, and the subsequently developing manifestations of secondary brain damage, which in principle can be prevented by the management procedures and therapeutical interventions. Therefore, a better outcome from severe head injury depends exclusively on a higher efficiency of the management and treatment in order to inhibit secondary brain damage. In a novel nationwide research program on "Neurotraumatology and Neuropsychological Rehabilitation" sponsored by the Federal Government, the University of Munich in collaboration with the Max-Planck-Institute of Neurobiology, Martinsried, formed a research consortium with major city hospitals in Munich, Augsburg, Ingolstadt, Murnau, Vogtareuth, and the Southern Bavaria rural area, which are caring for neurotrauma patients with severe head- or spinal cord injury. Together with the corresponding rescue- and emergency organizations, such as the Red Cross, fire brigades, etc. the consortium is carrying out a system analysis as a joint venture on the organization, logistics, management, patient referral, etc. in severe head injury. The analysis includes the assessment of outcome-relevant time intervals of providing emergency care during the preclinical phase until admission of the patient to the hospital, until termination of the diagnostic procedures after hospital admission, and of the clinical management. The present findings and results are based on these comprehensive investigations by the study group in collaboration with more than 30 hospitals, institutions, organizations, and of more than forty physicians, students, and statisticians. In total 194 patients suspected to suffer from severe head injury were prospectively documented with onset of the assessment in the preclinical rescue phase. Confirmation of severe head injury according to a priori established selection criteria was obtained in 100 patients, the remaining number of cases was excluded. The protocol by purpose did not impose study-specific requirements outside of the routine procedures, which are established for the preclinical care and early hospital management. An exception, however, was to collect arterial blood samples, if possible prior to intubation and ventilation, or administration of O2, in order to obtain early information on the acute respiratory state as a potential risk factor of the outcome. Arterial blood samples could be collected in 60 cases at the scene, in no less than 37 patients prior to intubation and ventilation. The data collected during the prehospital and early clinical phase on the temporal course of these patients provide valuable information with unmatched accuracy for evaluation of the management efficiency of the rescue system, transportation, and the clinical care. In conclusion, the prospective system analysis on the organization and management of patients with severe head injury is the first study of this type carried out in Germany. Due to the specific efforts of quasi on-line documentation of the patients' state and course of events, beginning at the scene of an accident and covering the first days at the hospital, data of high quality were obtained. The data flow during the investigation was maintained among others by regular conferences of the Study Group including the crew of documentation assistants at regular intervals. The presently reported phase-1 study was concluded in October 1997. It is followed by a phase-2 study with the attempt to collect prehospital- and early clinical management and care data in the catchment area on an epidemiological basis. (ABSTRACT TRUNCATED)

Craniocerebral Trauma↗
PubMed1999

Gastric irradiation for MALT lymphoma: reducing the target volume, fast!

A case of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma treated with radiotherapy alone is reported here. This case highlights treatment issues related to the variability in size and position of the stomach, and the substantial reduction in the size of the irradiated volume achieved by treating the patient in a fasting state.

Adult↗
PubMed1999

Osteolymphoma (primary bone lymphoma): an Australian review of 70 cases. Australasian Radiation Oncology Lymphoma Group (AROLG).

BACKGROUND: To examine prognostic factors, treatment outcomes and design future studies for Osteolymphoma (OL)--also known as primary bone lymphoma. METHODS: Between 1979 and 1993, 70 patients with OL were treated in nine Australian centres. The effect of patient-, tumour-, and treatment-related factors on local control, distant disease-free survival and overall survival were assessed by multivariate analysis. RESULTS: Most patients (94%) received radiotherapy (RT) (median dose 40 Gy) and 56% received chemotherapy. Multifocal disease was present in 20% of patients. The five year rates of overall survival and local control were 59% and 82%. Although there was a trend towards better results with the addition of chemotherapy, on multivariate analysis, there were no factors identified which appeared to impact upon overall and disease-free survival. Among the distant recurrences, there was a high proportion in bone (33%). Six patients suffered pathological fractures after treatment. CONCLUSION: High rates of local control were achieved by RT, but the overall survival remains relatively poor, worse than nodal lymphoma. The natural history of the disease suggests that OL may be a distinct entity, different to nodal lymphomas, so the results of clinical trials in nodal lymphoma may not be relevant to OL. Prospective studies could define the outcome of combined modality therapy and set a benchmark for testing further proposals, as well as improving our knowledge of the clinical features of OL.

Adult↗
PubMed1999

Mantle irradiation alone for clinical stage I-II Hodgkin's disease: long-term follow-up and analysis of prognostic factors in 261 patients.

PURPOSE: To evaluate mantle radiotherapy (MRT) alone as the initial therapy of patients with clinical stage (CS) I-II Hodgkin's disease (HD). PATIENTS AND METHODS: We performed a retrospective study of patients treated with MRT alone for CS I-II supradiaphragmatic HD between 1969 and 1994. Prognostic factor analysis was performed for progression-free survival (PFS) and overall survival (OS). Outcome was also assessed in favorable cohorts defined in the literature. RESULTS: There were 261 eligible patients. The median follow-up period for surviving patients was 8.4 years (range, 1.8 to 27.4 years). The 10-year OS rate was 73%. Multifactor analysis for OS showed that age was the only important prognostic factor. The 10-year PFS rate was 58%. On multifactor analysis for PFS, the most important prognostic factors were clinical stage, B symptoms, histology, number of sites, and tumor bulk. The 10-year PFS rate for lymphocyte-predominant disease was 81% for stage I and 78% for stage II. In favorable patient cohorts defined in the literature, the 10-year PFS rate ranged from 70% to 73% for the whole group and from 71% to 90% in patients with favorable stage I disease, but only from 48% to 57% in patients with favorable stage II disease. On competing-risks analysis, the cumulative 10-year incidence of first site of failure in the para-aortic/splenic region alone was 10.5%. Sixty percent of relapsed patients remain progression-free at 10 years after chemotherapy salvage. CONCLUSION: These results support the use of MRT alone in patients with favorable CS I HD and CS I-II HD with lymphocyte-predominant histology. The remainder of patients with CS I-II HD require more intensive treatment.

Adolescent↗
PubMed1998

Radiation myelopathy following transplantation and radiotherapy for non-Hodgkin's lymphoma.

BACKGROUND: Combined modality therapy with chemotherapy and radiotherapy has become increasingly popular in the management of solid malignancies. However, unexpected toxicities may arise from their interactions. METHODS AND MATERIALS: We report the case of a young woman with a large mediastinal non-Hodgkin's lymphoma who underwent high-dose chemotherapy with autologous bone marrow transplantation and involved field radiotherapy, and who developed radiation myelopathy after a latent period of only 3 months. The spinal cord dose did not exceed 40.3 Gy in 22 fractions over 4.5 weeks, which is well within accepted tolerance limits. She had no other identifiable risk factors for radiation myelopathy, suggesting an adverse drug-radiation interaction as the most likely cause of her injury. RESULTS AND CONCLUSIONS: This represents the first report of radiation myelopathy at accepted safe radiation doses following high-dose chemotherapy with autologous bone marrow transplantation, and we recommend caution in the choice of radiotherapeutic dose in this setting.

Adult↗
PubMed1998

Symptom duration and delay in referral for palliative radiotherapy in cancer patients: a pilot study.

OBJECTIVE: To estimate the frequency of delay in referral for palliative radiotherapy (PRT), and to identify factors associated with delay. DESIGN: Prospective survey over three months in 1997. SETTING: Radiotherapy department of a cancer centre in Melbourne, Victoria. PARTICIPANTS: 158 consecutive patients prescribed PRT in the lung, breast, urology and haematology units. MAIN OUTCOME MEASURES: Duration of symptoms; incidence of "unreasonable" delay in referral; and incidence of negative clinical outcome associated with referral delay. RESULTS: The median duration of symptoms before prescription of radiotherapy was four weeks. Thirty-eight patients (24%) were considered to have had an unreasonable delay in referral, with median symptom duration of 15 weeks, and median delay in referral of 12 weeks. Causes of delay were classified as "diagnostic uncertainty" (29%), "other treatment given" (18%), "patient related" (18%), "language difficulty" (3%), and "unexplained" (32%). Twenty-seven of these 38 patients (71%) had negative outcomes, including persistent pain, neurological deterioration and persistent respiratory symptoms. CONCLUSIONS: These data suggest that delay in referral for PRT is not uncommon, has a variety of causes and can result in negative clinical outcomes. There appears to be a need for greater awareness of patients' symptoms and of the role of PRT among clinicians caring for patients with cancer.

Aged↗
PubMed1998

Primary central nervous system lymphoma: age and performance status are more important than treatment modality.

PURPOSE: To assess prognostic factors and treatment modalities of patients with primary central nervous system lymphoma (PCNSL) in terms of response rates, patterns of failure and overall survival. METHODS AND MATERIALS: Sixty-two patients presenting with PCNSL between 1982 and 1994 at Peter MacCallum Cancer Institute with no evidence of human immunodeficiency virus infection were included in the study. Their median age was 60 years; World Health Organisation (WHO) performance status was > or = 2 in 85%. All patients were planned to receive whole brain irradiation; 7 also received spinal irradiation. The median planned dose to the target volume was 50.4 Gy. Twenty patients were planned to receive chemotherapy as well. Patients were followed up to June 20, 1995, giving a median follow-up for 14 surviving patients of 5.4 years, range 0.3 to 10.2 years. RESULTS: The clinical response rate to treatment was 77% [95% confidence interval (CI) 65 to 87%]. The estimated median overall survival was 20.6 months (CI 12.4 to 33.4 months). On univariate analysis male gender, age <60 years, WHO performance status < or = 1, treatment to the target volume > or = 45 Gy, and treatment with additional chemotherapy, were associated with a significantly better overall survival (p < 0.05). On multivariate analysis only age and performance status remained significant prognostic variables. Relapse involved the central nervous system or cerebrospinal fluid (CSF) in all patients with known sites of relapse except three who had ocular relapse only. There was a low incidence of relapse in the initial brain site (23% of known cases) and a high incidence (50%) of CSF/spinal cord relapse. Of 48 deaths, 15 were related to initial or subsequent treatment. CONCLUSIONS: Patient outcome is strongly influenced by age and performance status. Studies suggesting better survival for patients treated with chemoradiation may reflect patient selection rather than treatment variables. Optimal management remains to be defined. The high CSF/spinal relapse rate deserves particular attention.

Adolescent↗
PubMed1998

Gender differences in changes in subcutaneous and intra-abdominal fat during weight reduction: an ultrasound study.

OBJECTIVE: In weight-reducing programs, men usually display greater improvement in metabolic risk factors than women. This gender difference may be related to enhanced weight and fat loss due to a greater energy deficit in men. To clarify the relationship between changes in metabolic profile, body fat composition, and weight loss, both sexes were studied under a regimen in which similar amounts of weight were lost. RESEARCH METHODS AND PROCEDURES: A cross-sectional study using anthropometric (body mass index and waist-to-hip ratio), impedance (bioelectrical impedance analysis) and ultrasound measurement methods (thickness of subcutaneous fat layers, intra-abdominal sagittal diameter) were conducted. The metabolic risk profile was determined by measuring lipids, lipoproteins, and blood pressure. The weight loss program lasted 15 weeks: 3 weeks under controlled conditions in the hospital and 12 weeks on an ambulatory basis. Patients were instructed to follow a mixed diet. Calorie intake was restricted to 1500 kcal/day for the men and 1200 kcal/day for the women. Thirty-two subjects with obesity (16 men and 16 women), with a mean body mass index of 35 kg/m2--matched with regard to age, height, and body weight--took part in the study. RESULTS: As expected, weight loss was similar for both sexes (-13.4 kg vs. -12.8 kg). Also, body fat mass changed to the same extent in absolute and relative terms. The waist-to-hip ratio was identical before and after treatment in both sexes. The men lost more visceral fat than the women. This result is based on changes in intra-abdominal diameter as well as abdominal subcutaneous fat in relation to waist circumference. Changes in abdominal diameter were paralleled by reductions in triglycerides and increases in high-density lipoprotein-cholesterol. Subcutaneous fat loss was more pronounced in women than in men. DISCUSSION: Where absolute and relative reductions in body weight and body fat are similar, men mobilize more intra-abdominal fat than women, whereas women lose more subcutaneous fat. The greater reduction in intra-abdominal fat seen in men is accompanied by a more pronounced improvement in the metabolic risk profile. Therefore, greater improvement of risk factors in men is not only related to a greater negative energy balance, as shown in most studies, but is also sex-specific.

Abdomen↗
PubMed1998

Prospective analysis of patient management in severe head injury.

Severe head injury with and without peripheral trauma is the most frequent cause of death and of severe disability up to 45 years. Outcome is determined by two major factors, the extent and nature of the irreversible primary brain damage, and the evolving secondary sequelae, which contrary to the former are responsive in principle to therapeutic intervention. An improvement of outcome from severe head injury can be expected only from an increased efficiency of the measures to prevent secondary brain damage. A research consortium "Neurotrauma" was formed by the University of Munich in collaboration with almost all city hospitals in Munich, Augsburg, Murnau, Ingolstadt, Vogtareuth and Southern Bavaria, providing care for neurotrauma patients. These hospitals together with the associated organizations carry out a system analysis on the management, logistics, organization, patient referral, etc. In severe head injury. Data acquisition is e.g. also concerned with outcome-relevant time periods of emergency care measures in the pre-clinical phase until hospital admission, conclusion of diagnostic procedure, and of the initial clinical care. Current results and experiences with establishment of this comprehensive research organization are presented, where no less than 31 hospitals. Institutions and organizations, and a study group of more than 40 physicians, students and statisticians are collaborating. Emerging data appear to be suitable to further improve pertinent aspects of the patient management as a basis to lower the incidence of secondary brain damage from severe head injury.

Adult↗