The outer-membrane protein ShlB of Serratia marcescens activates and secretes hemolytic ShlA into the culture medium. Without ShlB, inactive ShlA (termed ShlA*) remains in the periplasm. Since ...Proteus mirabilis L-form cells lack an outer membrane and a periplasm, it was of interest to determine in which compartment recombinant ShlA* and ShlB are localized and whether ShlB activates ShlA*. The cloned shlB and shlA genes were transcribed in P. mirabilis stable L-form cells by the temperature-inducible phage T7 RNA polymerase. Radiolabeling, Western blotting, and complementation with C-terminally truncated ShlA (ShlA255) identified inactive ShlA* in the culture supernatant. ShlB remained cell-bound and did not activate ShlA without integration in an outer membrane. Although hemolytic ShlA added to L-form cells had access to the cytoplasmic membrane, it did not affect L-form cells. Synthesis of the large ShlA protein (165 kDa) in P. mirabilis L-form cells under phage T7 promoter control demonstrates that L-form cells are suitable for the synthesis and secretion of large recombinant proteins. This property and the easy isolation of released proteins make L-form cells suitable for the biotechnological production of proteins.
The amine metabolites HVA and 5-HIAA in the lumbar CSF of 15 patients with Huntington's chorea were determined. A negative correlation was found between the severity of symptoms and the CSF HVA, but ...not 5-HIAA levels. The mean HVA concentration was lower than that of a group of patients with miscellaneous neurological disorders, similar to that of a group with miscellaneous psychiatric disorders and higher than that of a group with Parkinson's disease. The mean 5-HIAA concentration was similar to that of the neurological group and higher than those of the groups with psychiatric disorders or Parkinson's disease. CSF HVA and 5-HIAA concentrations of a single patient with severe akinetic rigid Huntington's chorea were similar to those found in Parkinson's disease. The findings are discussed in relation to previous neuropathological observations and to reported effects of drugs on the choreic symptoms.
Magnetic stimulation was used to measure motor conduction time (MCT) between head and neck, and head and lumbar region, as well as amplitude of the motor evoked potential (MEP) in normal subjects and ...patients with multiple sclerosis (MS). Patients with definite MS had significantly longer MCTs and smaller amplitude MEPs than normal subjects when recording from arm and leg muscles. In a comparison with visual evoked potential (VEP) recordings, head to neck MCTs were abnormal less often than VEPs, and VEPs detected more silent lesions. Recording from leg as well as arm muscles significantly increased the yield of abnormal MCT measurements. The detection of silent lesions in the patients with definite MS was improved, but there was no improvement in the non-definite cases. Amplitude measurements provided very little extra diagnostic information over MCT measurements alone and did not improve the detection of silent lesions. Interside MCT differences yielded extra abnormalities when recording from the arms but not the legs. Interside MCT abnormalities increased the detection of silent lesions in both the definite and non-definite categories. It was concluded that the majority of useful diagnostic information in patients with MS should be obtainable from bilateral MCT (head to neck) measurements, together with estimation of interside MCT differences. However, VEP recording is a better diagnostic test for MS than MEP recording as more silent lesions are detected. This may be because MCT abnormalities tend to reflect the degree of pyramidal disability.
Transferable productive lysis in stable protoplast type L-form cells of Bacillus subtilis was produced by 6 phages out of 14 strains virulent for the parent B. subtilis 170 and 1997. Most of these ...phages lytic for L-forms show the phi 29 morphology characteristic for the smallest B. subtilis phages containing double-stranded DNA. Among 31 actinophages, 23 of which were virulent for Streptomyces hygroscopicus, only SLE 109 and phi c 31 gave productive infection of the stable protoplast type L-form of S. hygroscopicus NG 33--354. Electron microscopic investigation and treatment by DNAse demonstrated that infection of L-form cells is an adsorption-injection process, and that it is not caused by transfection of free phage DNA or endocytotic uptake of phage particles. Because in both stable L-forms cell wall biosynthesis is blocked irreversibly the results allow the conclusion that specific receptors must be localized in the cytoplasmic membrane for those phages producing transferable lysis in protoplast type L-forms. Localization of receptors for certain phages in the cytoplasmic membrane seems to occur in many Gram-positive bacteria, but not in Gram-negative bacteria.
Appropriate percutaneous carotid arteriography was carried out in 69 patients who presented with transient ischaemic attacks (TIAs) in the carotid territory. Major abnormalities were detected in 19 ...which included internal carotid stenosis (nine), internal carotid occlusion (seven), intracranial aneurysm (two), and cerebral angioma (one). Forty-five patients had normal angiograms and five slight irregularity of the internal carotid artery without stenosis. The symptoms and signs pertaining to the normotensive and hypertensive groups are presented. The outcome of stroke in 35 normotensives was as follows: three died of related disease, three are severely disabled, two have slight disability, eight have minor neurological residua, and 19 are normal. Fifteen patients had a diastolic blood pressure of above 105 mm Hg and the outcome of stroke in these patients treated with hypotensive agents was as follows: two died of related disease, two have severe and two moderate disablement, four have slight disability, one has minor residua, and four are normal. The pathogenesis of TIAs in relation to the two groups and the use of anticoagulant drugs and hypotensive agents are discussed.
The amine metabolites HVA and 5-HIAA in the lumbar CSF of 15 patients with Huntington's chorea were determined. A negative correlation was found between the severity of symptoms and the CSF HVA, but ...not 5-HIAA levels. The mean HVA concentration was lower than that of a group of patients with miscellaneous neurological disorders, similar to that of a group with miscellaneous psychiatric disorders and higher than that of a group with Parkinson's disease. The mean 5-HIAA concentration was similar to that of the neurological group and higher than those of the groups with psychiatric disorders or Parkinson's disease. CSF HVA and 5-HIAA concentrations of a single patient with severe akinetic rigid Huntington's chorea were similar to those found in Parkinson's disease. The findings are discussed in relation to previous neuropathological observations and to reported effects of drugs on the choreic symptoms.
To characterize a special kind of membrane structure, visible in the cytoplasmic membranes of a Streptomyces hygroscopicus strain, liposome membranes were prepared from their extracted lipid mixture ...and from their lipid fractions (phospholipids, glycolipids, neutral lipids) and investigated by freeze-fracture electron microscopy. Liposome membranes made of the extracted lipid mixture reveal this special membrane structure, named wafer structure, from its regular pattern of bulges (30-40 nm in diameter). That is the proof that this membrane feature is a lipid structure. Liposome membranes prepared from the lipid fractions show the wafer structure if they are made of the phospholipid fraction only or in combination of this fraction with one or both of the other lipid fractions, indicating that wafer structure formation is primarily connected with the phospholipid content of the membranes. The glycolipid- and neutral lipid fractions amplify this phospholipid structure only. Additional to the wafer structure a raspberry structure with bulges of 55-65 nm in diameter is visible in some case. Obviously both structures are related.
The role of the liver in lactate metabolism in an experimental low flow state induced by cardiac tamponade was investigated in dogs. Arterial and venous lactate, and pyruvate levels and ...arterio-venous oxygen content differences were measured for the liver, gut, forequarter and hind limbs. Cardiac output and regional blood flows were determined by electromagnetic flow probes. The contribution of the liver to the development of lactic acidosis was found to be variable. When hepatic oxygen consumption was decreased, the liver was documented as the major site of lactate production with an associated increase in the lactate-pyruvate ratio of hepatic venous blood. In some experiments, however, the hepatic oxygen consumption was maintained, or even increased slightly; in these circumstances the liver was, in part, responsible for the development of lactic acidosis by impaired lactate consumption.
A 15-bp mini-gene was introduced into
Bacillus subtilis and into stable protoplast-like L-forms of
Proteus mirabilis. This mini-gene encoded the peptide MVLFV and modeled a fragment of
Escherichia ...coli 23S rRNA responsible for
E. coli erythromycin (Ery) resistance. Expression of the introduced mini-gene conferred permanent Ery resistance on
B. subtilis. In L-forms of
P. mirabilis, the Ery-protective effect was maintained in the course of several generations. Herewith, the mechanism of Ery resistance mediated by expression of specific short peptides was shown to exist in evolutionary distant bacteria. Three new plasmids were constructed containing the gene under study transcriptionally fused with the genes encoding glutamylendopeptidase of
Bacillus licheniformis or δ-endotoxin of
Bacillus thuringiensis. The Ery resistance pentapeptide (E-peptide) mini-gene served as an efficient direct transcriptional reporter and allowed to select bacillar glutamylendopeptidase with improved productivity. The mini-genes encoding E-peptides may be applied as selective markers to transform both Gram-positive and Gram-negative bacteria. The small size of the E-peptide mini-genes makes them attractive selective markers for vector construction.
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