Immobilized enzymes: crystals or carriers?

The advantages of immobilized over soluble enzymes arise from their enhanced stability and ease of separation from the reaction media, leading to significant savings in enzyme consumption. Immobilization methods range from binding to prefabricated carrier materials to packaging in enzyme crystals or powders. During their use, mass-transfer effects can produce substrate or pH gradients, which reduce the reaction rates and product yields.

Improvement of the catalytic properties of penicillin G acylase from Escherichia coli ATCC 11105 by selection of a new substrate specificity.

Cloned penicillin G acylase (PGA) from Escherichia coli ATCC 11105 was mutagenized in vivo using N-methyl-N'-nitro-N-nitrosoguanidine. Mutants of PGA were selected by their ability to allow growth of the host strain E. coli M8820 with the new substrates phenylacetyl-beta-alanyl-L-proline (PhAc-beta Ala-Pro) phthalyl-L-leucine (Pht-Leu) or phthalylglycyl-L-proline (Pht-Gly-Pro) as sole source of proline and leucine respectively.

[BCG-vaccination in neonates as a cause of osteomyelitis--an argument against BCG-vaccination?].

BCG-osteomyelitis is a rare complication of BCG-vaccination. By means of a case report clinical and immunological findings are discussed. Contrary to the undramatic clinical symptoms the x-ray showed pronounced osteolytic lesions in the sternum.

Characterization of D-amino acid oxidase from Trigonopsis variabilis.

D-amino acid oxidase from Trigonopsis variabilis was purified to homogeneity as a well resolved flavoprotein. Specific activity of pure enzyme was 86.6 U/mg at 30 degrees C and pH 8.

Kinetic mechanism of D-amino acid oxidases from Rhodotorula gracilis and Trigonopsis variabilis.

The reaction of two D-amino acid oxidases from the yeasts Rhodotorula gracilis and Trigonopsis variabilis with the substrates alanine and valine in their 2-1H and 2-2H forms was studied employing the stopped-flow spectrophotometric technique. The turnover numbers at infinite substrate and oxygen concentrations were: 20,700/4,250 and 1,730/360 ([2-1H]/[2-2H]alanine and valine, respectively) for the Rhodotorula and 3,150/440 and 2,500/520 ([2-1H]/[2-2H]alanine and valine, respectively) for the Trigonopsis enzymes. The rates of anaerobic enzyme flavin reduction were 20,100/4,000 and 1,820/350 ([2-1H]/[2-2H]alanine and valine, respectively) for the Rhodotorula and 3,470/350 and 2,460/480 ([2-1H]/[2-2H]alanine and valine, respectively) for the Trigonopsis enzymes.

[Liver abscess caused by Aeromonas hydrophila].

Because of the rare incidence of liver abscess in childhood and of extremely rare observed Aeromonas hydrophila as pathogen of such a disease we report on a 14 7/12 year old girl with a liver abscess. For the last 4 years she had to be enrolled in chronic hemodialysis. The treatment comprised opening of the abscess cavity and drainage, and antibiotic therapy with cefotiam.

[Bacterial bone and joint infections in childhood--a review. 4. Subacute and primary-chronic osteomyelitis, rare forms of osteomyelitis].

This is an overview of the most important aspects of pathogenesis, etiology, diagnostics, therapy and differential diagnostics of the subacute and primary chronic osteomyelitis in children. This group of disease includes Brodie's abscess, plasma cellular osteomyelitis, sclerosing osteomyelitis (Garré) and the chronic recurrent multifocal osteomyelitis. The treatment of children with these not completely understood diseases requires a close cooperation between pediatricians, pediatric surgeons and radiologists.

[Bacterial bone and joint infections in childhood--a review. 3. Bacterial arthritis].

This overview presents the most important topics of etiology, pathogenesis, diagnostics, differential diagnostics and treatment of septic arthritis in children. A child with bacterial arthritis is always a case of emergency. Only immediate and adequate treatment can avoid permanent sequelae.

[Bacterial bone and joint infections in childhood--a review. 2. Septic bursitis].

This is an overview of modern aspects concerning diagnostics and therapy in in children with septic bursitis. A close cooperation of pediatricians, pediatric surgeons, microbiologists and radiologists in this field is essential.

[Bacterial bone and joint infections in childhood--a review. 1. Acute hematogenous osteomyelitis].

This is an overview of modern aspects concerning diagnostics and therapy in children with acute hematogenous osteomyelitis. A close cooperation of pediatricians, pediatric surgeons, microbiologists and radiologists in this field is essential.

[Diagnosis, therapy and prevention of necrotizing enterocolitis in newborn infants].

The necrotizing enterocolitis is a severe and frequently fulminant disease with a considerable mortality. The main event is the enteral septicemia. Only prompt diagnostics and adequate therapy permit the survival of the newborns.

[Bronchopulmonary foregut malformations with communication to the esophagus].

Congenital abnormal communications between separated pulmonary tissue and the oesophagus are rarities. Only about 50 cases have been reported in the literature. For all different forms the term of bronchopulmonary foregut malformation (BPFM) was first applied by Gerle and his coworkers in 1968.

[Current status of surgery for abnormalities in newborn age and infancy].

Own experiences about the modern standard of malformation surgery in newborns and young babies are demonstrated. Progress in prenatal diagnosis, perioperative management, operative strategy and operative technique improved the prognosis. Necessary is optimal interdisciplinary cooperation of all participants and special responsibility of the surgeon.

[Pneumococcal infections in children: osteomyelitis and arthritis].

A pneumococci-osteoarthritis in 8 children is reported on. In almost all the cases an adequate therapy (antibiotics, immobilization, physical therapy) resulted in a healing process free of defects with a full maintenance of the articular function. Besides by staphylococci and haemophilus influenzae, pneumococci too use to play a role as pathogenic organisms for osteomyelitis and arthritis.

[Intrathoracic gastric duplication with intrapulmonary abscesses and perforation into the bronchial system--pathologico-anatomic peculiarities and diagnostic problems].

Gastric and enteric cysts represent genuine duplications. With regard to their genesis opinions are divided. These duplications may perforate into the lung parenchyma and/or the bronchial system, giving rise to specific symptoms.

[Experiences in the diagnosis and therapy of neurogenic disorders of bladder emptying].

Today extensive urodynamic investigations are indispensable for diagnosing and for an on-target treatment of neurogenic bladder dysfunction. Classifications and forms used according to functional aspects are explained. Possible treatment methods are commented in respect of own experiences, especially with regard to chemotherapy, intermittent catheterisation, transurethral electrostimulation, biofeedback therapy and supravesical urinary diversion.

Experience in surgical treatment of pulmonary and bronchial tumours in childhood.

From the patient material of three paediatric surgical centres and the patient material of the paediatric surgical hospitals of Zurich, Switzerland and Leipzig, GDR, 24 cases of lung and bronchial tumours are reported. The aim of this review is to show a spectrum of the cases observed in our region. The most frequent of these very rare tumours was pulmonary blastoma, followed by endobronchial adenoma in its different variants.

[Appendicitis in childhood].

Appendicitis in infancy has proved to be accompanied by particular problems in general and differential diagnosis. Recommendations are made for proper establishment of case histories as well as for clinical examination and surgical approach, with reference being made to the authors' own experience. The authors' perforation rate was 7.