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Biomedical subjects

A Wagner

Publications and source records attributed to A Wagner.

At least 271 records · Page 15Linked to original sources

Collection of peripheral blood stem cells (PBSC) after chemotherapy and administration of rhGM-CSF in children weighing less than 17 kg.

Peripheral blood stem cells (PBSC) were collected from six children weighing less than 17 kg. Stem cell pools had been expanded by chemotherapy and rhGM-CSF. Nineteen procedures were performed with a continuous-flow separator (CS 3000 plus) using central venous access. The extracorporeal line was primed with red blood cells and 5% albumin (HA). Acid-citrate-dextrose:- formulae A(ACD-A) was added in a median ratio 1:11 (range 1:9-1:15). A median number of 5.6 x 10(8) kg-1 NC (3.5-9.7) and 7.1 x 10(6) kg-1 CD34+ cells (2.1-26.1) were collected per patient. Four patients were transplanted with PBSC and showed normal haematopoietic recovery (leucocytes > 1000 microL-1 between days 11 and 12). The results show that successful PBSC collection and transplantation is possible even in small paediatric patients. Administration of growth factors results in a marked increase of peripheral white blood cells and in a higher yield of NC and CD34+ cells in PBSC collections.

Antineoplastic Combined Chemotherapy Protocols↗

[The fully implantable minimally invasive hepatic artery catheter for locoregional chemotherapy of nonresectable liver metastases in defective conventional implanted therapy catheters].

Dysfunction of arterial access devices used in association with intra-arterial chemotherapy for the treatment of unresectable liver metastases usually requires stopping the therapy or relaporotomy and reimplantation of a new arterial catheter. In this article our initial experience of a new technique, the so-called MIAH catheter (minimally invasive hepatic artery catheter) in 36 patients (age 37-78 years) are reported. The MIAH catheter was percutaneously inserted into the subclavian artery under sonographic guidance and advanced via the descending aorta selectively into the hepatic artery. Finally it was connected to a totally implantable pump. There were no deaths related to the operation. Operative or early complications occurred in 5 cases (13.8%); late complications were seen in 13 patients (36.1%). Nevertheless continuation of intra arterial chemotherapy was possible in all cases. In cases of dysfunction of conventional arterial access devices the MIAH catheter makes it possible to continue intra-arterial chemotherapy without requiring laporotomy.

Adult↗

The management of pneumothorax with the thoracic vent versus conventional intercostal tube drainage.

The thoracic vent is a new minimally invasive device for the treatment of spontaneous and iatrogenic pneumothorax. It consists of a polyurethane catheter connected to a plastic chamber containing a one-way valve. As there is no need to connect the thoracic vent to an underwater seal device, immobilization and hospitalization can be avoided. So far the performance of the thoracic vent has been evaluated only in patients without pleural effusions and without signs of tension pneumothorax. Hence, we have performed a randomized study comparing the treatment of pneumothorax by means of the thoracic vent versus conventional intercostal tube drainage in 30 patients, including some with tension pneumothorax. 17 patients were treated with the thoracic vent, 13 with conventional intercostal tube drainage. We found no significant differences in the rate of reexpansion and rate of complications between the group treated with the thoracic vent and the group treated with intercostal tube drainage, but the patients treated with the thoracic vent needed significantly less analgesics. 70% of the patients treated with the thoracic vent were successfully managed on an outpatient basis. All patients treated with intercostal tube drainage were hospitalised; duration of inpatient-therapy was 8 +/- 6.2 days (mean +/- SD).

Adolescent↗

Peripheral blood stem cell (PBSC) collection in extremely low-weight infants.

While PBSC collection has become a safe procedure for adults, only a few reports exist about its efficacy, safety and feasibility in paediatric patients, especially extremely low-weight infants. We describe successful PBSC collection in three infants of less than 10 kg body weight (BW; range: 6.92-9.4 kg) suffering from stage IV neuroblastoma. Harvest of PBSC started after mobilisation with high-dose chemotherapy and G-CSF, as soon as 1.0% CD34+ cells were detected. Collections were performed using a Baxter CS-3000 Plus separator primed with a mixture of irradiated, white cell-depleted and CMV-negative packed red cells resuspended in 5% human albumin and diluted with saline to match the patient's haematocrit. Performing a median of four, (4-7, median, range) procedures we collected at least 4 x 10(8)/kg BW nucleated cells (NC) from all three patients. The infants were not sedated and showed no serious side-effects. All three children were successfully transplanted with myeloid engraftment in 8 (7-9) days, independence from red cell support was achieved in 15 (10-20) days and from platelet transfusions in 25 (14-29) days after PBSC infusion. We conclude that PBSC harvesting using continuous flow cell separators is safe, even in low-weight infants of less than 7 kg BW.

Adrenal Gland Neoplasms↗

[MRSA (methicillin-resistant Staphylococcus aureus) infections in patients with pulmonary diseases].

Methicillin-resistant Staphylococcus aureus (MRSA) has become a major nosocomial pathogen. We investigated MRSA-infections in patients with pulmonary diseases referring to epidemiological aspects. Between 9/92 and 2/92 we found MRSA-infections in our hospital in 24 patients (11 female, 13 male, average age 54.6 years). Clinical presentation, main and accompanying disorders and previous antibiotic therapy regimens were registered. Strains were typed using DNA-RFLP and lysotyping. MRSA detection were done in specimen from sputum (12/24) and from the bronchial secret (9/24). In 18/24 cases the MRSA-colonisation was associated with infection. In 15/24 cases the first acquisition of MRSA happened in our hospital, 6/24 times the germ was carried off other institutions and in 3/24 cases it was possibly community acquired. Most frequently patients suffered from bronchial cancer (6/24), from chronical bronchitis (5/24), from pneumonia (4/24) or Cystic fibrosis (4/24). Usually the patients showed other severe comorbidity. 13/24 patients had an antibiotic course before detecting MRSA. Typing revealed a strain already known in different hospitals of Berlin, another known strain of northern Germany and two so far unknown strains. Of interest was a different behaviour of resistance and the lost of resistance of strains in the course. MRSA-infection in pulmonary medicine emerged as a problem mostly in patients with multimorbidity and severe underlying diseases. Change of resistance in strains and new strains were observed.

Adult↗

[Results of critical care management of patients after bone marrow transplantation].

In a retrospective study we investigated the clinical course of patients who required intensive care support after bone marrow transplantation. Out of 25 patients only 5 (20%) survived treatment in the intensive care unit (ICU) and this group showed a significantly lower age, lower APACHE III and organ-failure scores and higher serum albumin values, as well as a longer interval between bone marrow transplantation and admission to intensive care. However, no patient requiring mechanical ventilation primarily for pneumonia or other infections arising as a complication of bone marrow transplantation survived intensive care. All patients requiring ventilation for more than 24 hours died in hospital. Of the 5 patients surviving ICU treatment only 3 were eventually discharged from hospital and only one single patient was alive after 6 months. Hence, current intensive care management appears to be indicated in only a small group of patients after bone marrow transplantation.

APACHE↗

Augmented reality environment for temporomandibular joint motion analysis.

The principles of interventional video tomography were applied for the real-time visualization of temporomandibular joint movements in an augmented reality environment. Anatomic structures were extracted in three dimensions from planar cephalometric radiographic images. The live-image fusion of these graphic anatomic structures with real-time position data of the mandible and the articular fossa was performed with a see-through, head-mounted display and an electromagnetic tracking system. The dynamic fusion of radiographic images of the temporomandibular joint to anatomic temporomandibular joint structures in motion created a new modality for temporomandibular joint motion analysis. The advantages of the method are its ability to accurately examine the motion of the temporomandibular joint in three dimensions without restraining the subject and its ability to simultaneously determine the relationship of the bony temporomandibular joint and supporting structures (ie, occlusion, muscle function, etc) during movement before and after treatment.

Adult↗

[Emergency respirator therapy in intermediate altitude with the Ambu Matic].

Portable emergency ventilators are commonly used in a pre-hospital setting in the transport of critically ill patients also in hypobaric environments. The aim of our trial was to evaluate the influence of moderate altitude at 2700 m compared to 171 m altitude on minute ventilation and blood gas analysis in healthy volunteers during mechanical ventilation with the Ambu Matic ventilator. At 2700 m altitude, the delivered minute volume increased by 13.8%. paCO2 decreased by 9.2% (p < 0.01 for all reported changes). No statistical change in paO2 at 2700 m altitude was observed. These changes are of sufficient magnitude and importance to require monitoring of minute volume to prevent volutrauma or barotrauma.

Adult↗

Interaction of guanosine nucleotides and their analogs with elongation factor Tu from Thermus thermophilus.

Transient kinetic experiments on the interaction of nucleotide-free EF-Tu from Thermus thermophilus with nucleotides using intrinsic protein fluorescence, extrinsic nucleotide fluorescence and fluorescence resonance energy transfer show that nucleotide binding is in general at least a two-step process. The first step is a weak initial binding, which is followed by a relatively slow isomerization of the protein-nucleotide complex in which changes of both intrinsic and extrinsic fluorescence, as well as energy transfer, occur. The values obtained for the equilibrium and kinetic constants confirm the earlier observation that EF-Tu has a higher affinity for GDP than GTP. This is mainly due to a lower dissociation rate constant for GDP, in combination with a somewhat higher effective association rate constant. Modifications of the triphosphate moiety of GTP are quite well tolerated by EF-Tu, with GTP gamma S displaying the same affinity as GTP and with GppNHp and GppCH2p being only ca. 2-3-fold less strongly bound. Caged GTP is bound about 6-fold more weakly than GTP. These results suggest that the binding of GppNHp and GppCH2p is likely to be similar to that of GTP. The photolytic protecting group of caged GTP (or the loss of one of the negative charges on the gamma-phosphate group) appears to interfere to a certain extent with the interaction with the protein, but the affinity is high enough to permit generation of 1:1 complexes for dynamic structural studies. Discrimination between GDP and ADP is dramatic, with a difference of 6 orders of magnitude in affinity.

Adenosine Diphosphate↗

Site-directed mutagenesis of Thermus thermophilus elongation factor Tu. Replacement of His85, Asp81 and Arg300.

His85 in Thermus thermophilus elongation factor Tu (EF-Tu) was replaced by glutamine, leucine and glycine residues, leading to [H85Q]EF-Tu, [H85L] EF-Tu and [H85G]EF-Tu, respectively. Asp81 was replaced by alanine leading to [D81A]EF-Tu, and replacement of Arg300 provided [R300I]EF-Tu. Glycine in position 85 of domain I induces a protease-sensitive site in domain II and causes complete protein degradation in vivo. A similar effect was observed when Asp81 was replaced by alanine or Arg300 by isoleucine. Degradation is probably due to disturbed interactions between the domains of EF-Tu.GTP, inducing a protease-sensitive cleavage site in domain II. [H85Q]EF-Tu, which can be effectively overproduced in Escherichia coli, is slower in poly(U)-dependent poly(Phe) synthesis, has lower affinity to aminoacyl-tRNA but shows only a slightly reduced rate of intrinsic GTP hydrolysis compared to the native protein. The GTPase of this protein variant is not efficiently stimulated by aminoacyl-tRNA and ribosomes. The slow GTPase of [H85Q]EF-Tu increases the fidelity of translation as measured by leucine incorporation into poly(Phe) in in vitro poly(U)-dependent ribosomal translation. Replacement of His85 in T. thermophilus EF-Tu by leucine completely deactivates the GTPase activity but does not substantially influence the aminoacyl-tRNA binding. [H85L]EF-Tu is inactive in poly(U)-dependent poly(Phe)-synthesis. The rate of nucleotide dissociation is highest for [H85L]EF-Tu, followed by [H85Q]EF-Tu and native T. thermophilus EF-Tu. Mutation of His85, a residue which is not directly involved in the nucleotide binding, thus influences the interaction of EF-Tu domains, nucleotide binding and the efficiency and rate of GTPase activity.

Amino Acid Sequence↗

Salmon HNF1: cDNA sequence, evolution, tissue specificity and binding to the salmon serum albumin promoter.

cDNA clones coding for the transcription factor HNF1 have been isolated from Atlantic salmon (Salmo salar L.). The 559 amino acid residue long encoded protein shows high conservation, with respect to other species, of the domains necessary for DNA-binding: the HNF1 atypical homeodomain, the POU related sequence and the dimerisation domain. Alignment with rat HNF1 protein reveals that the transcription activation domains ADI and ADIII are relatively conserved in the fish sequence whereas ADII is not. Phylogenetic analysis indicates that higher vertebrate HNF1s and the related variant HNF1s (vHNF1s) are more closely related to each other than any of them is to Salmon HNF1, suggesting that the duplication event from which HNF1 and vHNF1 genes arose occurred after the divergence of the tetrapod and teleost ancestors. Northern blot analysis show a single transcript, of about 2.6 kb, which is not exclusive to liver but is also present in intestine, kidney and spleen. Using polymerase chain reaction (PCR) we have isolated the salmon albumin gene promoter which contains, upstream of the TATA box, a potential binding site for HNF1. The salmon HNF1 protein synthesized by in vitro transcription-translation of the full-length cDNA is able to bind specifically with equivalent affinities to either the rat or salmon albumin promoter.

Amino Acid Sequence↗

Tracheal rupture after emergency intubation during cardiopulmonary resuscitation.

We describe a case of tracheal rupture following an emergency intubation during cardiopulmonary resuscitation. This complication occurring during resuscitation has not apparently been reported previously. Possible causes during the management of cardiac arrest are discussed with references to previously described cases of tracheal rupture.

Aged↗