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Biomedical subjects

B Schmidt

Publications and source records attributed to B Schmidt.

At least 235 records · Page 13Linked to original sources
PubMed1996

The relationship of the buccal branch of the facial nerve to the parotid duct.

PURPOSE: This cadaver dissection studied the relationship of the buccal branch of the facial nerve to the parotid duct and its relevance to surgical procedures in this area. MATERIALS AND METHODS: Ten cadaveric heads (twenty sides) were dissected. The superficial tissues were removed, and the buccal branch of the facial nerve and the parotid duct were identified. The vertical and horizontal relationships were recorded and analyzed. RESULTS: Eighty-five percent of the cadavers had a single buccal branch of the facial nerve, whereas 15% had two branches. In 75% of cases, the nerve was inferior to the duct as it emerged from the parotid gland, whereas in 25% of cases the nerve crossed the duct, usually from superior to inferior. CONCLUSION: The buccal branch of the facial nerve has a close relationship with the parotid gland for over 2.5 cm after it emerges from the parotid gland; it normally lies inferior to the duct. This relationship is of importance in performing parotid gland surgery, parotid duct surgery, and some facial cosmetic surgery.

Cheek↗
PubMed1996

A cyclophilin-like peptidyl-prolyl cis/trans isomerase from Legionella pneumophila--characterization, molecular cloning and overexpression.

Legionella pneumophila is the causative agent of a severe form of pneumonia in humans (Legionnaires' disease). A major virulence factor, the Mip protein (FK506-binding protein, FKBP25mem), belongs to the enzyme family of peptidyl-prolyl cis/trans isomerases (PPlases). Here we show that L. pneumophila Philadelphia I possesses an additional cytoplasmic PPlase at a level of enzyme activity comparable to that of FKBP25mem. The N-terminal amino acid sequence of the purified protein was obtained by Edman degradation and showed that the protein is a member of the cyclophilin family of PPlases. The Icy gene (Legionella cyclophilin) was cloned and sequenced. It encodes a putative 164-amino-acid protein with a molecular mass of 17968 Da called L. pneumophila cyclophilin 18 (L.p.Cyp18). Amino acid sequence comparison displays considerable similarity to the cytoplasmic and the periplasmic cyclophilins of Escherichia coli with 60.5% and 51.5% identity, respectively. The substrate specificity and inhibition by cyclosporin A revealed a pattern that is typically found for other bacterial cyclophilins. An L. pneumophila Cyp18 derivative with a 19-amino-acid polypeptide extension including a 6-histidine tag and an enterokinase cleavage site exhibits PPlase activity when produced at high levels in E. coli K-12. After removal of the extension by enterokinase, the properties of the recombinant Cyp18 were indistinguishable from those of the authentic enzyme. In order to investigate the influence of Cyp18 on intracellular survival of L. pneumophila an Icy-negative L. pneumophila strain was constructed. Compared with the wild-type strain, the mutant did not exhibit a significant phenotype but was 10-fold less invasive for Acanthamoeba castellanii. Like human cyclophilin, the L. p. Cyp18 exhibits nuclease activity, but this enzymatic activity does not appear to be linked with the native structure of the protein.

Amino Acid Isomerases↗
PubMed1996

Multiple fistulas and tracheobronchial stenoses require extensive stenting of the central airways and esophagus in squamous-cell carcinoma.

We report here on two cases of double airway and esophageal stenting in patients with multiple esophagotracheal fistulas and stenoses of the airways and esophagus due to squamous-cell carcinoma. Dumon stents and a Strecker device were used for tracheobronchial stenting. Covered Gianturco Z-stents were implanted into the esophagus. In one case, extrinsic compression of the trachea and tumor progression required recanalization by Nd:YAG laser. Clinical improvement led to discharge of the patients within two weeks after the procedure. The results show that simultaneous implantation of stents in the central airways and covered Gianturco Z-stents in the esophagus is an effective therapeutic strategy in patients with tracheal and esophageal obstructions and esophagorespiratory fistulas. Further systematic studies evaluating double stenting are warranted.

Aged↗
PubMed1996

Membranes in artificial organs.

Membrane processes by a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extra-corporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.

Artificial Organs↗
PubMed1996

Plasma therapy at Klinikum Grosshadern: a 15-year retrospective.

Immediately after the availability of highly permeable membranes in 1979, membrane plasma separation was introduced as a mode of extracorporeal blood purification by the nephrology group at Klinikum Grosshadern of the Ludwig Maximilians University of Munich (F.R.G.). The new therapy was applied primarily in the management of immunologically mediated renal and extrarenal disorders as well as in paraproteinemias. We also have witnessed a widespread application of this extracorporeal treatment as a last resort in otherwise refractory clinical conditions. Over the years, the group at Grosshadern has contributed to the development, as well as to the laboratory and clinical testing, of new plasma separation membranes, simplified plasmapheresis formats (e.g., spontaneous membrane plasma separation), and several plasma fractionation procedures (e.g., cascade filtration, adsorption). Whenever indicated and possible, plasma fractionation procedures, rather than unselective plasma exchange, are performed in an appropriate clinical situation.

Chemical Fractionation↗
PubMed1996

Oesophageal burn caused by sucking a 1.5 volt battery.

We report the case of a 4-year-old boy who sustained an oesophageal burn grade II-III due to ingestion of an alkaline substance from a leaking cylindric 3.3 cm diameter battery, by putting the battery to his mouth and sucking the caustic solution. Lye ingestion by sucking a big cylindrical alkaline battery has not yet been reported in the medical literature. We recommend the production of safer alkaline battery cover tubes in order to eliminate any possibility of leakage. Accidents like this might occur more often, since battery collecting and recycling is becoming more common.

Burns, Chemical↗
PubMed1996

Detection of Borrelia burgdorferi-specific DNA in urine specimens from patients with erythema migrans before and after antibiotic therapy.

A nested PCR was developed for the detection of Borrelia burgdorferi-specific DNA in the urine of patients with erythema migrans. The target for the nested PCR was a specific region of the flagellin gene; the detection limit was less than five organisms of B. burgdorferi including all three species B. burgdorferi sensu stricto, B. afzelii, and B. garinii. A prospective, controlled, blinded study was performed with 26 patients with erythema migrans to evaluate the nested PCR method with clinical samples. B. burgdorferi-specific DNA could be detected in urine specimens from 22 of 24 patients with erythema migrans (sensitivity, 91.61%). Immediately after therapy, 11 of 19 patients still yielded positive results (58%). Eight weeks after therapy, 2 of 16 patients (13%) were positive by PCR of urine, and 20 weeks after treatment none of seven investigated urine samples was reactive. Essential for the sensitivity that was obtained was the development of a simple DNA extraction procedure. The results of the study indicate that the described method is highly sensitive and allows for the effective control of the efficacy of antibiotic therapy in patients with early Lyme borreliosis.

Adult↗
PubMed1996

Thrombin inhibitors reduce intrapulmonary accumulation of fibrinogen and procoagulant activity of bronchoalveolar lavage fluid during acute lung injury induced by pulmonary overdistention in newborn piglets.

We determined whether antithrombin (AT III) or hirudin (a specific thrombin inhibitor) reduce both the accumulation of fibrinogen in lung parenchyma and the procoagulant activity of bronchoalveolar lavage (BAL) fluid during acute lung injury induced by pulmonary overdistention. Newborn piglets were randomized to six-hourly infusions of AT III concentrate, a continuous infusion of recombinant hirudin, or no anticoagulant therapy. All animals were subjected to 24 h of identical mechanical ventilation at high peak pressures (3.9 kPa or 40 cm H2O). Tidal volumes were raised to a mean of 69 mL/kg in all three groups. Mean AT III levels in supplemented piglets (n = 22) were increased to 1.46 (SD 0.24) U/mL at 24 h, compared with 0.67 (SD 0.16) U/mL in controls (n = 23). The median activated partial thromboplastin time in animals receiving hirudin (n = 18) was prolonged to 53 s versus 34 s in untreated animals. The intrapulmonary accumulation of i.v. administered 125I-fibrinogen was reduced by AT III concentrate or hirudin, compared with untreated littermates (p = 0.003). The procoagulant activity of BAL fluid was also decreased by both thrombin inhibitors (p = 0.001). Intrapulmonary accumulation of fibrinogen and the procoagulant activity of BAL fluid were reduced by AT III or hirudin during lung injury caused by pulmonary overdistention. Future investigations should determine whether tangible clinical benefits result from this reduced potential for fibrin deposition in the injured lung.

Animals↗
PubMed1996

Acute necrotizing myopathy and podophyllin toxicity. Report of a fatal case.

A 21 year old male ingested podophyllin in a suicide attempt. The disorder was marked by seizures, coma, peripheral neuropathy, renal failure and acute necrotizing myopathy, an unusual finding. The coma and systemic disturbances resolved within three weeks. The myopathy resolved in 7 weeks, demonstrating a high capacity of muscle recuperation. The sensorimotor peripheral neuropathy persisted until the patient's death 9 weeks after the ingestion, due to septicemia. This report confirms the transient central neurotoxicity of podophyllin and persistent peripheral neurotoxicity of podophyllin, and describes a reversible necrotizing myopathy associated to mitochondrial abnormalities, a still unreported feature of podophyllin toxicity.

Adult↗
PubMed1996

Guanidinoacetate methyltransferase deficiency: the first inborn error of creatine metabolism in man.

In two children with an accumulation of guanidinoacetate in brain and a deficiency of creatine in blood, a severe deficiency of guanidinoacetate methyltransferase (GAMT) activity was detected in the liver. Two mutant GAMT alleles were identified that carried a single base substitution within a 5' splice site or a 13-nt insertion and gave rise to four mutant transcripts. Three of the transcripts encode truncated polypeptides that lack a residue known to be critical for catalytic activity of GAMT. Deficiency of GAMT is the first inborn error of creatine metabolism. It causes a severe developmental delay and extrapyramidal symptoms in early infancy and is treatable by oral substitution with creatine.

Alleles↗
PubMed1996

[Psychoanalytic considerations of right extremist orientation of male adolescents].

Giving a case example of an male adolescent with radical right-wing attitudes, the lack of male identification as well as in unresolved dyadic fixation to the mother will be shown. Though the radical right-wing orientation the adolescent tries on the basis of a phallic narcissistic conflict to establish bordes against an unresolved dyadic fixation to his mother.

Adolescent↗
PubMed1996

[Thoracic neuroblastoma].

Between 1984 and 1994 operations for thoracic neuroblastomas were performed in ten patients (six boys, four girls). The median age was 17 months, the follow-up ranges between 6 months and 11 years; one patient died 3 years postoperatively. Complete excision of the tumour was the only therapy in four patients presenting with stage I (n = 2) and II a (n = 2) disease. Following resection, chemotherapy was carried out in four patients with stage II b (n = 2) and III (n = 2). Chemotherapy was the primary procedure in two patients with stage IV; resection of the tumour and postoperative chemotherapy followed. Thoracic neuroblastomas have a favorable outcome. The basic biology seems to differ from that of other sites and may not warrant such aggressive surgical therapy. Complete excision is recommended, if possible, but is not imperative.

Chemotherapy, Adjuvant↗
PubMed1995

Small-angle X-ray solution scattering study on the dimerization of the FKBP25mem from Legionella pneumophila.

The dimerization of the FK506-binding peptidyl-prolyl cis/trans-isomerase (PPIase) FKBP25mem (Mip (macrophage infectivity potentiator) protein) from Legionella pneumophila was studied by small-angle X-ray solution scattering. A value of 44 kDa, independent on the protein concentration between 2 and 13 mg/ml, confirming that FKBP25mem is a dimer was found for the molecular mass of the protein. The radius of gyration of the protein is 3.3 nm and the Porod volume 87 nm3. A model of the shape of FKBP25mem was evaluated from the scattering curve. Each monomer consists of a proximal and a peripheral domain, which are perpendicular to each other. The envelope of the crystallographic model of human FKBP12 fits well into the peripheral domain. The contact regions between the two monomers in the dimeric protein are probably located between the N-terminal parts of the monomers.

Amino Acid Isomerases↗
PubMed1995

The race-specific elicitor, NIP1, from the barley pathogen, Rhynchosporium secalis, determines avirulence on host plants of the Rrs1 resistance genotype.

NIP1, a small phytotoxic protein secreted by the barley pathogen Rhynchosporium secalis, is a race-specific elicitor of defense responses in barley cultivars carrying the resistance gene, Rrs1. Co-inoculation employing spores from a virulent fungal race together with the NIP1 protein converted the phenotype of the interaction from compatible to incompatible only on Rrs1-containing plants. In addition, transformation of a virulent fungal race with the nip1 gene yielded avirulent transformants. This demonstrated that the protein is the product of a fungal avirulence gene. The fungal genome was found to contain a single copy of the nip1 gene. Sequence analysis of nip1 cDNA and genomic clones revealed that the gene consists of two exons and one intron. The derived amino acid sequence comprised a secretory signal peptide of 22 amino acids and a cysteine-rich mature protein of 60 amino acids. All fungal races that were avirulent on barley cultivars of the Rrs1 resistance genotype carry and express the nip1 gene and secrete an elicitor-active NIP1 polypeptide. In contrast, races lacking this gene were virulent. In addition, single nucleotide exchanges were detected in the coding region of the nip1 alleles in one virulent fungal race and in a race whose interaction with barley is not controlled by the Rrs1 gene. The resulting exchanges of single amino acids render the gene products elicitor-inactive. Thus, the R.secalis-barley interaction provides the first example of a pathosystem conforming to the gene-for-gene hypothesis in which a plant with a particular resistance gene recognizes a pathogen by a virulence factor, i.e. one of its offensive weapons. On the fungal side, in turn, recognition by the host plant is eluded by either deletion of the encoding gene or alteration of the primary structure of the gene product.

Amino Acid Sequence↗
PubMed1995

A novel amino acid modification in sulfatases that is defective in multiple sulfatase deficiency.

Multiple sulfatase deficiency (MSD) is a lysosomal storage disorder characterized by a decreased activity of all known sulfatases. The deficiency of sulfatases was proposed to result from the lack of a co- or posttranslational modification that is common to all sulfatases and required for their catalytic activity. Structural analysis of two catalytically active sulfatases revealed that a cysteine residue that is predicted from the cDNA sequence and conserved among all known sulfatases is replaced by a 2-amino-3-oxopropionic acid residue, while in sulfatases derived from MSD cells, this cysteine residue is retained. It is proposed that the co- or posttranslational conversion of a cysteine to 2-amino-3-oxopropionic acid is required for generating catalytically active sulfatases and that deficiency of this protein modification is the cause of MSD.

Alanine↗
PubMed1995

Localization of the insulin-like growth factor II binding site to amino acids 1508-1566 in repeat 11 of the mannose 6-phosphate/insulin-like growth factor II receptor.

The mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGF-II receptor) binds insulin-like growth factor II (IGF-II) with high affinity. To localize the IGF-II binding site within the 15 repeating units that form the extracytoplasmic domain of the receptor, purified human M6P/IGF-II receptor was digested with thermolysin, and the fragments were analyzed for their ability to bind 125I-IGF-II in a cross-linking assay. Two IGF-II-binding receptor fragments of 23 and 37 kDa were purified. Sequence analysis revealed that the fragments consist of disulfide connected peptides comprising amino acids 1331-1566 and 1331-1697 of the receptor repeats 9-12. In a second approach we expressed truncated forms of the M6P/IGF-II receptor fused to the C terminus of the extracytoplasmic domain of the 46-kDa mannose 6-phosphate receptor. Fusion proteins containing M6P/IGF-II receptor repeats 10-15, 10-11, or 11-15 bound IGF-II, whereas a fusion protein containing the single repeat 10 failed to bind. This result indicates that repeat 11 (amino acids 1508-1650) is sufficient for binding of IGF-II. Residues 1508-1566, which are shared by the 23-kDa IGF-II-binding fragment and repeat 11, are proposed to form the IGF-II binding site of the M6P/IGF-II receptor.

Amino Acid Sequence↗
PubMed1995

High-performance liquid chromatographic determination of the rhamnolipids produced by Pseudomonas aeruginosa.

The bacterial biosurfactants 3-[3'-(L-rhamnopyranosyloxy)decanoyloxy]decanoic acid (RL-1) and 3-[3'-(2"-O-alpha-L-rhamnopyranosyl-alpha-L-rhamnopyranosyloxy) decanoyloxy]decanoic acid (RL-2) were isolated from Pseudomonas aeruginosa DSM 2659 cultures. An HPLC method was developed for the p-bromophenacyl esters of the rhamnolipids. Separation was obtained within 25 min on a RP C18 column using a linear gradient of water-acetonitrile (30:70 to 0:100) and UV detection (265 and 320 nm). Linearity of response existed for 1.2-25 microg of the RL-1 and 1.8-25 microg of the RL-2-p-bromophenacyl ester (0.9-19.2 microg RL-1 and 1.3-18.0 microg RL-2). The reproducibility of the entire analytical method (extraction, derivatisation) was tested.

Carbohydrate Sequence↗