Rationally engineered variants of S-adenosylmethionine (SAM) synthase: reduced product inhibition and synthesis of artificial cofactor homologues.

S-Adenosylmethionine (SAM) synthase was engineered for biocatalytic production of SAM and long-chain analogues by rational re-design. Substitution of two conserved isoleucine residues extended the substrate spectrum of the enzyme to artificial S-alkylhomocysteines. The variants proved to be beneficial in preparative synthesis of SAM (and analogues) due to a much reduced product inhibition.

Freehand three-dimensional assessment of left ventricular volumes and ejection fraction with ultrasound contrast agent LK565.

AIMS: Accurate assessment of left ventricular function by determining left ventricular volumes and ejection fraction is important in evaluating the prognoses of patients with heart failure. Two-dimensional (2D) echocardiography suffers from low correlation with reference methods like ventriculography. Three-dimensionally (3D) assessed data have been proved to have better conformity. Endocardial border delineation remains a problem, however, especially in patients with suboptimal recordings. Few data exist on 3D-echocardiographic volumetry with ultrasound contrast agents (UCAs). We evaluated the second-generation UCA LK565 for its boundary-tracing capacities in freehand 3D echocardiography in a phase II clinical trial. Safety and efficacy of the novel contrast agent were also evaluated. METHODS AND RESULTS: Forty patients between the age of 42 and 77 were included in this trial. Left ventricular end-systolic and -diastolic volume (LVESV, LVEDV) and ejection fraction (EF) were determined by either 2D or 3D freehand second harmonic echocardiography with and without use of LK565. Parameters were compared statistically with ventriculography performed in 35 patients. Immune response to LK565 was evaluated by analysing phagocytosis capacity and kinetics of inflammatory cytokines (TNF-alpha, IL-4, IL-10, IFN-gamma). Patients were monitored for adverse events up to 72 h after application of the UCA. Calculated values for left ventricular volumes and ejection fraction correlated best for freehand 3D echocardiography in combination with LK565 (r=0.92 for LVEDV; r=0.96 for LVESV; r=0.94 for EF). Excellent left ventricular contrast enhancement was achieved for approximately 8 min. A reversible saturation of phagocytosis capacity for monocytes and neutrophils set in with a maximum peak at 6h. No significant increase in cytokine expression was observed. CONCLUSION: LK565 improves feasibility of endocardial border delineation in 3D echocardiography, leading to better correlation of left ventricular volumetry with reference methods. Efficacy and safety of LK565 are equivalent to those of conventional UCAs.

alpha-catenin expression is decreased in human gastric cancers and in the gastric mucosa of first degree relatives.

BACKGROUND AND AIMS: The role of altered cell adhesion is critical for the development of epithelial cancers. E-cadherin plays an important role in the maintenance of cell-cell adhesion and its function is thought to be regulated by its associated cytoplasmic proteins, such as alpha-catenin and beta-catenin. To determine the role of alpha-catenin expression in gastric carcinogenesis, we studied its expression in human gastric cancer and in the gastric mucosa of first degree relatives with no clinical disease. METHODS: alpha-Catenin expression was assessed by immunohistochemical analysis and reverse transcriptase-polymerase chain reaction (RT-PCR) using gastric tissue specimens from patients with gastric cancer and from the gastric mucosa of first degree relatives of gastric cancer patients and healthy controls. RESULTS: mRNA levels of alpha-catenin were reduced or absent in 13 of 19 gastric cancer tissues, which differed significantly from levels found in the tumour free gastric mucosa of cancer patients (p<0.05). Of the cancer samples with altered alpha-catenin mRNA levels, alpha-catenin expression was negative in seven and decreased in six cases. Interestingly, decreased alpha-catenin mRNA expression also occurred in the mucosa of the corpus (11/18) and antrum (4/18) of first degree relatives. In the corpus biopsies alpha-catenin expression was more often decreased or lost compared with the antrum biopsies in first degree relatives and healthy controls (p<0.05). Immunohistochemical analysis revealed membranous expression of alpha-catenin in gastric cancer cells and the non-malignant gastric epithelium. However, some cancers also exhibited loss of membranous staining. Generally, loss or downregulation of alpha-catenin mRNA in the gastric mucosa was associated with Helicobacter pylori infection (p<0.05). CONCLUSION: Our findings suggest that loss or downregulation of alpha-catenin expression may be an early event in gastric carcinogenesis and may be associated with H pylori infection.

Intraoperative angiography and embolization in intracranial AVM's and aneurysms.

Intraoperative angiography allows for control procedures for exstirpation of arteriovenous malformations and clipping of problematic aneurysms during the entire operation. During intraoperative embolizations, it is especially helpful to see whether the occlusion of the nidus of an arteriovenous malformation is complete. The method is easy to perform; there were no complications in 19 cases.

[Blood pressure regulation in neurosurgical interventions in the lumbar area in the seated patient]. / Zur Blutdruckregulation bei neurochirurgischen Eingriffen im Lumbalbereich am sitzenden Patienten.

It has been proved studies of the physiology of the circulatory system that a sufficient regulatory mechanism is present during intervertebral disk operations on the sitting patient. So this positioning variant can be well recommended from an anaesthesiological point of view. Patients without a sufficient blood pressure regulation should be excepted from this positioning variant.

[Microorganisms in home-care inhalation devices]. / Mikroorganismen in Inhalationsgeräten der Heimtherapie.

Contamination of inhalation equipment used at home, cleaning procedures, and the occurrence of potentially pathogenic micro-organisms in mouthwash water was studied in 55 patients. Fungi in the oropharyngeal space were found in 58%, Staphylococcus aureus in 29%, Enterobacteriaceae in 47% and Pseudomonas aeruginosa in 11%. Contamination with potentially pathogenic micro-organisms occurred in 64% of inhalation equipment and inhalation solutions. In a total of 151 samples from the equipment Klebsiella was present in 14%, Enterobacter in 10%, Serratia and Acinetobacter in 11% each, Pseudomonas in 5% and Staphylococcus aureus in 4.5%. In three cases the same serotype of Ps. aeruginosa was present in the oropharyngeal cavity and inhalation equipment. In most cases the cleansing of the inhalation equipment had been inadequate. Only 36% of those questioned cleaned the equipment immediately before use, only 4 of 20 stated that they washed their hands before use. Subjective assessment of the value of inhalation treatment was either "very good" or "good" in 80%.