Search PubMed⌕ Search

Biomedical subjects

S Albrecht

Publications and source records attributed to S Albrecht.

At least 73 records · Page 4Linked to original sources
PubMed1998

A preliminary study of the use of peer support in smoking cessation programs for pregnant adolescents.

This article describes preliminary findings of an experimental, randomized, three-group, controlled design examining the effectiveness of a smoking cessation intervention for pregnant teens. The three groups are: Teen FreshStart with a buddy program (TFSB), a Teen FreshStart program (TFS) without peer support, and the Usual Care (UC) control group. Forty-six subjects completed the post-intervention assessment of smoking status. The TFSB group consistently achieved greater smoking cessation across all measures when compared to the subjects in the other two groups. These results indicate that the use of peer support may be an effective adjunct in smoking cessation programs for pregnant adolescents.

Adolescent↗
PubMed1998

Immunological and functional analyses of the extracellular domain of human tissue factor.

Tissue factor (TF) initiates the extrinsic pathway of blood coagulation via formation of an enzymatic complex with coagulation factor VII/VIIa (FVII/VIIa). Although FVII is the only known ligand for TF, several reports in recent years have shown that the function of TF may not be limited to serving as a trigger of coagulation but that TF could also play a role in cellular signaling, metastasis, adhesion and embryogenesis. To explore the loci of the extracellular domain of TF important for its function, we analyzed the functional and immunological epitopes of TF1-219 by the use of both E. coli expressed TF variants encompassing various portions of the extracellular domain of TF and different anti-TF monoclonal antibodies (mAbs). N- and C-terminally truncated TF variants were analyzed for their VIIa-dependent procoagulant activity (PCA). The results obtained are in agreement with previously performed mutant and structural analyses of the interaction of FVII/FVIIa with the extracellular domain of TF. In addition, we observed that combination of two TF variants, Ec-TF1-122 and Ec-TF120-219, yields a soluble and active two-chain TF molecule with remarkable PCA. The reaction patterns of anti-TF mAbs with truncated TF variants and synthetic TF-derived peptides demonstrated that at least three distinct conformation-dependent epitope areas of TF (residues 1-25, 175-202, and 181 -214, respectively) are detected by these mAbs raised against native TF. In fact, mAbs, which are directed to the same epitope area of TF, behave very similar in various applications including immunohistochemistry and clotting tests. Since mAbs directed to the C-terminal epitope area of TF (residues 181-214) influence TF activity independent of FVIIa-binding, this region may be involved in functions of TF distinct from haemostasis.

Antibodies, Monoclonal↗
PubMed1998

Comparison of tissue polypeptide antigen (TPA) with cancer antigen 15-3 (CA 15-3) and carcinoembryonic antigen (CEA) in follow-up of breast cancer.

Cancer antigen 15-3 (CA 15-3), carcinoembryonic antigen (CEA) and tissue polypeptide antigen (TPA) were measured in 679 sera of breast cancer patients and in 94 sera of women without breast cancer. The tumour markers were determined using immunoluminometric assays (ILMA). The assays are characterised by an inter-assay-imprecision and intra-assay-imprecision <4 %. The breast cancer patients were staged according to the TNM classification stage 0-IV (by UICC) in patient groups with a compatible prognosis. Median and range of each stage were investigated. The cut-off values (95th and 97.5th percentile of control group) of CA 15-3, CEA and TPA were determined; specificity, sensitivity, positive and negative predictive value (PV) and efficiency were investigated for these cut-off's and the receiver operating characteristic (ROC) curves were calculated. The differences between control group and stage 0-3 were shown as non-significant for CA 15-3 and CEA but significant for TPA. Significant differences were found in stage 4 for all three tumour markers. The three tumour markers did not have differences in specificity, positive and negative PV and efficiency. TPA and CA 15-3 demonstrated comparable results in sensitivity and ROC curve analyses. These results were better than those from CEA.

Adult↗
PubMed1998

Exophytic primitive neuroectodermal tumor of the spinal cord.

We present a case of an exophytic spinal primitive neuroectodermal tumor that, radiologically, simulated an extramedullary nerve sheath tumor, meningioma, or metastatic tumor deposit. MR imaging provided discrete anatomic localization of the tumor, enabling exclusion of multicentricity in the brain and spinal cord.

Adult↗
PubMed1997

Mice lacking factor VII develop normally but suffer fatal perinatal bleeding.

Blood coagulation in vivo is initiated by factor VII (FVII) binding to its cellular receptor tissue factor (TF). FVII is the only known ligand for TF, so it was expected that FVII-deficient embryos would have a similar phenotype to TF-deficient embryos, which have defective vitello-embryonic circulation and die around 9.5 days of gestation. Surprisingly, we find that FVII-deficient (FVII-/-) embryos developed normally. FVII-/- mice succumbed perinatally because of fatal haemorrhaging from normal blood vessels. At embryonic day 9.5, maternal-fetal transfer of FVII was undetectable and survival of embryos did not depend on TF-FVII-initiated fibrin formation. Thus, the TF-/- embryonic lethal and the FVII-/- survival-phenotypes suggest a role for TF during embryogenesis beyond fibrin formation.

Animals↗
PubMed1997

[Selenium administration in patients with sepsis syndrome. A prospective randomized study].

PATIENTS AND METHOD: In this study the effect of antioxidative therapy with sodium selenite was investigated in patients with systemic inflammatory response syndrome (S. I. R. S.) and multiple organ failure. 40 patients were included in this prospective randomized study. The patients were observed over a period of 28 days. The letality rate within 28 days was excepted as main criteria. The Apache-II and the MOF-Score of Goris were used as clinical parameters. 20 patients were treated with sodium selenite over a period of 28 days. RESULT: This antioxidative therapy reduced the letality rate from 40 to 15%.

Antioxidants↗
PubMed1997

[Selenium administration in severe inflammatory surgical diseases and burns in childhood].

PATIENTS AND METHOD: Substitution of selenium was performed in the University Clinic of Paediatric Surgery in Dresden in the time from 1994 to 1996 in 34 children aged 1 to 16 years with severe inflammatory surgical diseases as well a s widespread burns. Seven further patients have been examined within this time who have not received substitution of selenium as preliminary comparison group. All these patients fulfilled the criteria of "Systemic Inflammatory Response Syndrome" (SIRS). The following paraclinical parameters were examined: white cell count, interleukin 6, C-reactive protein, fibrinogen, malondialdehyde, activity of glutathione peroxidase in plasma and level of selenium in plasma and whole blood. RESULTS: Patients with initially low level of selenium who received substitution of selenium reached normal ranges more quickly than patients without substitution. Originally partly elevated values of malondialdehyde as sign of increased peroxidation of lipids were normalized under substitution of selenium. Initially low activity of selenium level in plasma showed a clear increase under substitution of selenium as sign of increased protection of the cell membrane. CONCLUSION: The substitution of selenium in children with SIRS is a supportive therapy.

Adolescent↗
PubMed1997

[Does selenium prevent peroxynitrite formation from NO in vascular surgery interventions? A clinical study].

Nitric oxide seems to play a protective role in the pathogenesis of arteriosclerosis. It appears to protect the tissue during reperfusion in vascular surgery. High values of NO show an inverse correlation to the severity of arteriosclerosis. In our opinion selenium should be substituted in order to enhance the activity of the glutathione peroxidase. This means an effective protection against the high production of peroxinitrite in patients with arteriosclerosis. A comparison of the corresponding redox pairs SeO3(2-)/SeO4(2-) and HOONO/HONO allows the conclusion that sodium selenite can be a direct antioxidant thereby.

Aged↗
PubMed1997

Medulloblastomas of the desmoplastic variant carry mutations of the human homologue of Drosophila patched.

Inactivating mutations in the PTCH gene, a human homologue of the Drosophila segment polarity gene patched, have been identified recently in patients with nevoid basal cell carcinoma syndrome. These patients are predisposed to various neoplasias including basal cell carcinomas and medulloblastomas (MBs). To determine the involvement of PTCH in sporadic MBs, which represent the most frequent malignant brain tumors in children, we screened for PTCH alterations in an unselected panel of 64 biopsy samples from 62 patients and four continuous MB cell lines, all derived from patients with sporadic MBs. Using single-strand conformational polymorphism analysis, we screened exons 2-22 and detected nonconservative PTCH mutations in 3 of 11 samples from sporadic cases of the desmoplastic variant of MB but none in 57 MBs with classical (nondesmoplastic) histology. In two of the tumors with mutations and in two additional desmoplastic cases, loss of heterozygosity was found at 9q22. These findings suggest that PTCH represents a tumor suppressor gene involved in the development of the desmoplastic variant of MB.

Adolescent↗
PubMed1997

Familial spongiform encephalopathy associated with a novel prion protein gene mutation.

Human prion diseases include Creutzfeldt-Jakob disease, Gerstmann-Stráussler-Scheinker disease, fatal familial insomnia, and kuru. Each of these diseases has a specific clinical presentation while spongiform encephalopathy, neuronal loss, and gliosis are their neuropathological hallmarks. We studied a Brazilian family with an autosomal dominant form of dementia. Nine members of the family were affected by a dementia with frontotemporal clinical features, with a mean age at onset of 44.8 +/- 3.8 years and a mean duration of symptoms of 4.2 +/- 2.4 years. Neuropathological examination of 3 patients showed severe spongiform change and neuronal loss in the deep cortical layers and in the putamen, but minimal gliosis in the most severely affected areas. The putamen and cerebellum, but not other areas of the affected brain, displayed prion protein immunoreactivity. A novel prion protein gene mutation causing a nonconservative substitution at codon 183 was identified in 2 neuropathologically confirmed affected individuals (mother and son). The mutation was transmitted in a mendelian fashion to 12 members of the family. Therefore, we identified a novel prion disease variant characterized by an early onset and long duration of the symptoms, severe spongiform change with minimal gliosis, associated with a prion protein gene mutation at codon 183.

Adult↗
PubMed1997

Pathoanatomic findings in radiohumeral epicondylopathy. A combined anatomic and electromyographic study.

Several authors believe that a compression syndrome of the radial nerve or its muscle branches is responsible for the clinical picture of radiohumeral epicondylopathy. Various structural and functional stenoses have been discussed as possible causes. We performed systematic electromyographies (EMGs) on the extensors subdividing from the radial epicondyle and found significant changes (P < 0.05) in 27/51 patients regarding latency, velocity of nerve conduction and rate of polyphasic potentials. Especially affected were the extensor carpi radialis brevis and the extensor digitorum muscle. In order to clarify causal anatomic correlations, we performed a longitudinal and cross-sectional study on a total of 40 arms from cadavers. We found constant variations from the topographic anatomy published in the standard literature which corresponded to the EMG results in the area between the epicondyle and place of entry into the supinator muscle. In addition, we observed a regularly occurring ulnar deviation from the distal part of the extensor carpi radials brevis origin which protrudes over the plane of insertion of the joint extensor tendon aponeurosis and forms in most cases the arcade of Frohse. Because the deep radial branch and its parallel muscular branches cross this part at an obtuse angle, we think that dynamic pressure on a nerve without structural influences is the pathoanatomic result of this heterogeneously interpreted clinical picture.

Cadaver↗
PubMed1997

Diagnostic and therapeutic strategies for the operative treatment of radiohumeral epicondylopathy.

We examined the extent and effect of an assumed neuromuscular transmission disorder by performing a prospective clinical study on 75 patients with therapy-resistant radiohumeral epicondylopathy. Before operating, we diagnosed with electromyography an increased rate of polyphasic potentials of the long wrist extensors as well as a prolonged motor latency of the respective muscles. Disordered neuromuscular recruitment combined with a reduced maximum strength and elasticity corresponding to the suspected damage to the distal part of the motor neuron could be proven. Both effects were significantly reversible (P < 0.001) through operative intervention. We found a significant correlation (> 0.90) between the normalization of the motor latency and increased strength. Subgroups were formed according to different preoperative diagnostic efforts and differing radicality regarding the type of soft-tissue operation performed; thus, the clinical validity of the findings diagnosed in the anatomical/ electrophysiological part of the study was additionally examined. The failure rate varied between 10% and 30%, depending on the radicality of the tenotomy, which could be interpreted as a general indication for a complete extensor carpi radialis brevis tendon release. In this connection it is remarkable that the clinical result of electromyographically localized damage in the area between the epicondyle and arcade of Frohse could not be improved through open neurolysis. Dealing with strictures located on the proximal side of the epicondyle on the other hand, this technique seems to play an important role in the recurrence prophylaxis.

Activities of Daily Living↗
PubMed1997

[Postoperative pain after interventions in the area of the mouth-jaw-face].

In order to establish effective postoperative analgesia we studied the incidence and significance of pain following maxillofacial surgery. The trial included 102 patients undergoing one of six different surgical procedures. Postoperative pain was assessed using a visual analogue scale (VAS) and the short form of the McGill Pain Questionnaire (SF-MPQ) up to the third postoperative day. Postoperative pain intensity was significantly correlated to operating time, the frequency of analgesic demand and the type of surgery (orthognathic surgery > TMJ surgery > osteosynthetic surgery > osteotomy of impacted third molars > tumor resection > removal of osteosynthetic materials). Patient's age, sex and ethnic origin did not significantly affect the severity of postoperative pain.

Adolescent↗
PubMed1997

[Results of surgical treatment of radio-humeral epicondylopathy].

We examined extent and affection of an assumed neuromuscular transmission disorder by performing a prospective clinical study on 75 patients with therapy-resistant radiohumeral epicondylopathy. Before operation, we electromyographically diagnosed an increased rate of polyphasic potentials of the long wrist extensors as well as a prolonged motor latency of the respective muscles. Corresponding to a hereby implied damage to the distal part of the motor neuron, disordered neuromuscular recruitment combined with a reduced maximum strength and -elasticity could be proven. Both effects were significantly reversible (p < 0.001) through operative intervention. We found a significant correlation (corr < 0.90) between the normalization of the motor latency and increased strength. Subgroups were formed depending on different pre-operative diagnostic efforts and differing redicality regarding the performed soft-tissue operation, thus the clinical validity of the findings diagnosed in the anatomic and neurophysiologic part of the study was additionally examined. It was proven that the failure rate varies between 10% and 30%, depending on the radicality of tenotomy, which could be interpreted as a general indication for complete extensor carpi radialis brevis tendon release. In this connection it is remarkable that the clinical result of an electromyographically localized damage in the area between epicondyle and arcade of Frohse could not be improved through open neurolysis. Dealing with strictures located on the proximal side of the epicondyle on the other hand, this technique seems to play an important role for recurrence prophylaxis.

Adult↗
PubMed1997

Pharmacokinetic-pharmacodynamic modelling of the EEG effects of Ro 48-6791, a new short-acting benzodiazepine, in young and elderly subjects.

The objectives of this study were to explore, by a modelling approach, in nine young (24-28 yr) and nine elderly (67-81 yr) male subjects, the pharmacokinetics and pharmacodynamics of Ro 48-6791, a new water soluble benzodiazepine. A microprocessor-controlled i.v. infusion pump generated linearly increasing arterial plasma concentrations until predetermined EEG and clinical end-points were attained. This concentration was maintained for 15 min and thereafter the infusion was discontinued. Haemodynamic and respiratory variables were monitored continuously. At full reorientation of the subject, a second infusion cycle was started under the same conditions to investigate the reproducibility of the concentration-effect relationship. The plasma concentration-time profiles of Ro 48-6791 were fitted accurately to an open three-compartment model. Plasma concentrations of Ro 48-6792, an N-dealkylated metabolite, accumulated during the course of the study. Pharmacokinetic variables of Ro 48-6791 were similar for both groups. The largest differences between young and elderly subjects, respectively, were found for clearance (mean 85 (SD 23) vs 71 (15) litre h-1) and k12 (11 (7) vs 7 (3) h-1). The concentration-median EEG frequency relationship was described with a sigmoid Emax model. Elderly subjects showed slightly increased drug sensitivity compared with young subjects (EC50 72 (25) and 44 (15) micrograms litre-1 in young and elderly subjects, respectively). The concentration-response data of the second infusion cycle deviated from the fitted curve suggesting either development of acute tolerance to the EEG effects of Ro 48-6791 or a role for drug metabolites. Because of the differences in sensitivity and clearance, lower doses of Ro 48-6791 should be administered to elderly compared with young subjects in order to achieve similar effects.

Adult↗
PubMed1997

A comparison of remifentanil and alfentanil in patients undergoing major abdominal surgery.

The efficacy and safety of remifentanil and alfentanil for patients undergoing major abdominal surgery were compared. Premedicated patients received a loading dose of remifentanil (1.0 microgram.kg-1; n = 116) and a continuous infusion of 0.5 microgram.kg-1.min-1, or a loading dose of alfentanil (25 micrograms.kg-1; n = 118) and a continuous infusion of 1.0 microgram.kg-1.min-1. Propofol was administered (10 mg every 10 s) until loss of consciousness. Patients' lungs were ventilated with 66% nitrous oxide and 0.5% (end-tidal) isoflurane in oxygen. The study drug infusion rate was reduced by 50% 5 min after intubation. Alfentanil was discontinued 15 min before the end of surgery, whereas remifentanil was continued in the immediate postoperative period at a reduced dose. Responses to intubation (28%) and skin incision (17%) occurred approximately twice as often in the alfentanil group (15% and 8%; p = 0.014 and p = 0.037, respectively). More patients receiving alfentanil had one or more responses to surgery (72% vs. 57%; p = 0.016). The time to spontaneous respiration, adequate respiration, response to verbal command and time to recovery room discharge were similar. However, owing to decreased variability, the time to extubation was shorter with remifentanil than with alfentanil (p = 0.048). There was a similar overall incidence of adverse events in both groups, 82% and 75% of patients, respectively. Adverse events associated with remifentanil were rapidly controlled by dose reductions. The incidence of intra-operative hypotension and bradycardia was higher in the remifentanil group (p < or = 0.033). An initial remifentanil infusion rate of 0.1 microgram.kg-1.min-1 titrated to individual need provided postoperative pain relief in the presence of adequate respiration in 71% of patients. When using remifentanil in the immediate postoperative setting, rapid administration of bolus doses and infusion rate increases resulted in a relatively high incidence of muscle rigidity, respiratory depression and apnoea. Changing the postoperative regimen to avoid rapid changes in remifentanil blood concentration resulted in more effective analgesia and dramatically reduced the incidence of adverse events during this period. In patients undergoing major abdominal surgery, remifentanil appears to offer superior intra-operative haemodynamic stability during stressful surgical events compared with alfentanil without compromising recovery from anaesthesia. Remifentanil can be administered as a postoperative analgesic agent at a starting dose of 0.1 microgram-.kg-1.min-1; however, it should only be used in the presence of adequate supervision and monitoring of the patient. Administration of bolus doses is not recommended in this setting.

Abdomen↗
PubMed1997

Surviving reengineering: coping in today's health care environment.

Stress reactions during times of organizational change are only to be expected. In the volatile world of health care there are no exceptions. It has been said that the only constant is change. As a result, it is imperative that we develop effective methods to deal with the ever-changing world. The unspoken life-long employment contract no longer exists. Given that change is a constant--and that all change, even good change causes stress--how do we survive? Can we do better than survive? What about "surthriving"? It is possible to actually grow and develop during stressful times of change.

Employment↗