Congenital heart block associated with a maternal anti-HsEg5-like autoantibody.
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Biomedical subjects
Publications and source records attributed to P Lorenz.
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Proteolytic enzymes are ubiquitous in occurrence, being found in all living organisms, and are essential for cell growth and differentiation. The extracellular proteases are of commercial value and find multiple applications in various industrial sectors. Although there are many microbial sources available for producing proteases, only a few are recognized as commercial producers. A good number of bacterial alkaline proteases are commercially available, such as subtilisin Carlsberg, subtilisin BPN' and Savinase, with their major application as detergent enzymes. However, mutations have led to newer protease preparations with improved catalytic efficiency and better stability towards temperature, oxidizing agents and changing wash conditions. Many newer preparations, such as Durazym, Maxapem and Purafect, have been produced, using techniques of site-directed mutagenesis and/or random mutagenesis. Directed evolution has also paved the way to a great variety of subtilisin variants with better specificities and stability. Molecular imprinting through conditional lyophilization is coming up to match molecular approaches in protein engineering. There are many possibilities for modifying biocatalysts through molecular approaches. However, the search for microbial sources of novel alkaline proteases in natural diversity through the "metagenome" approach is targeting a hitherto undiscovered wealth of molecular diversity. This fascinating development will allow the biotechnological exploitation of uncultured microorganisms, which by far outnumber the species accessible by cultivation, regardless of the habitat. In this review, we discuss the types and sources of proteases, protease yield-improvement methods, the use of new methods for developing novel proteases and applications of alkaline proteases in industrial sectors, with an overview on the use of alkaline proteases in the detergent industry.
UNLABELLED: Pseudoexfoliation syndrome (PEX) has been suggested to represent a blood-aqueous barrier impairment leading to a higher protein content in aqueous humour of eyes with PEX. However, the nature of a prospective PEX protein has not yet been described. We set out to reevaluate protein content and examine protein composition for prospective PEX protein candidates in aqueous humour of eyes with PEX syndrome. Aqueous humour of 52 patients with PEX and 38 without PEX signs was sampled during cataract or glaucoma surgery. Total aqueous protein concentration in the samples was analysed in 43 PEX specimens and 32 non-PEX specimens according to Bradford. Aqueous protein composition of all samples was determined by sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS PAGE) and silver staining. Screening for amyloids was performed in nine PEX samples and six non-PEX samples by Congo Red staining and polarised light microscopy. Aqueous protein concentration was not significantly increased in PEX eyes in comparison with non-PEX eyes. Furthermore, we could not detect any characteristic difference in protein band sizes of the two groups after SDS PAGE. However, we were able to show the presence of amyloid exclusively in aqueous humour of PEX patients. CONCLUSION: our results do not confirm a generally higher protein concentration in pseudoexfoliation syndrome eyes. This does not necessarily contradict a blood-aqueous barrier impairment but illustrates the variance in protein concentration between and within the two groups. No characteristic protein band allocatable to pseudoexfoliation syndrome proteins could be detected in any of the samples. However, our findings support the theory that the pseudoexfoliation syndrome is associated with an amyloid of a serum protein.
Primary cutaneous B cell lymphomas are defined as non-Hodgkin lymphomas that occur in the skin without extracutaneous involvement for 6 mo after diagnosis. They are characterized by a less aggressive course and better prognosis than their nodal counterparts. According to the European Organization for Research and Treatment of Cancer classification, the major subentities of primary cutaneous B cell lymphoma are follicle center cell lymphomas, immunocytomas, and large B cell lymphomas of the leg, which differ considerably regarding their clinical behavior, the former two being indolent, the latter being of intermediate malignancy. In this study, we applied a single cell polymerase chain reaction approach to analyze immunoglobulin V(H)/V(L) genes in 532 individual B lymphocytes from histologic sections of four follicle center cell lymphomas localized on the head and trunk, and four large B cell lymphomas on the leg. We found: (i) in six of eight patients a clonal heavy chain, and in seven of eight patients a clonal light chain rearrangement, all being potentially productive; (ii) no bias in VH gene usage, in four of seven light chain rearrangements the V kappa germline gene IGVK3-20*1 was used; (iii) no biallelic rearrangements; (iv) all V(H)/V(L) genes are extensively mutated (mutation rate 5.4-16.3%); (v) intraclonal diversity in six of eight cases (three of each group); and (vi) low replacement vs silent mutation ratios in framework regions indicating preservation of antigen-receptor structure, as in normal B cells selected for antibody expression. Our data indicate a germinal center cell origin of primary cutaneous follicle center cell lymphomas and large B cell lymphomas independent of those belonging to one of these subentities.
Kinetoplastid parasites compartmentalize the first seven enzymes of glycolysis in a peroxisome-like microbody, the glycosome. Genes encoding the most abundant protein of the glycosomal membrane, GIM5, have been cloned and the protein characterized. Two genes, GIM5A and GIM5B, encode 26 kDa proteins. Although many microbody membrane proteins are conserved in evolution, the only homologues of GIM5 in the available databases are from the closely related kinetoplastids Trypanosoma cruzi and Leishmania. The N- and C-termini are conserved between the two genes, and between species, and are oriented towards the cytosol. They are separated by a short loop that is located between two transmembrane domains and shows almost no sequence conservation. This suggests that the N- and C-terminal domains are more important for function. GIM5 forms dimers in vivo. Overexpression of GIM5B inhibits growth, whereas depletion of GIM5 to below 10% of wild-type levels is very rapidly lethal. This novel organellar membrane protein is therefore essential for bloodstream trypanosome survival.
Two Ras effector pathways leading to the activation of Raf-1 and phosphatidylinositol 3-kinase (PI3K) have been implicated in the survival signaling by the interleukin 3 (IL-3) receptor. Analysis of apoptosis suppression by Raf-1 demonstrated the requirement for mitochondrial translocation of the kinase in this process. This could be achieved either by overexpression of the antiapoptotic protein Bcl-2 or by targeting Raf-1 to the mitochondria via fusion to the mitochondrial protein Mas p70. Mitochondrially active Raf-1 is unable to activate extracellular signal-related kinase 1 (ERK1) and ERK2 but suppresses cell death by inactivating the proapoptotic Bcl-2 family member BAD. However, genetic and biochemical data also have suggested a role for the Raf-1 effector module MEK-ERK in apoptosis suppression. We thus tested for MEK requirement in cell survival signaling using the interleukin 3 (IL-3)-dependent cell line 32D. MEK is essential for survival and growth in the presence of IL-3. Upon growth factor withdrawal the expression of constitutively active MEK1 mutants significantly delays the onset of apoptosis, whereas the presence of a dominant negative mutant accelerates cell death. Survival signaling by MEK most likely results from the activation of ERKs since expression of a constitutively active form of ERK2 was as effective in protecting NIH 3T3 fibroblasts against doxorubicin-induced cell death as oncogenic MEK. The survival effect of activated MEK in 32D cells is achieved by both MEK- and PI3K-dependent mechanisms and results in the activation of PI3K and in the phosphorylation of AKT. MEK and PI3K dependence is also observed in 32D cells protected from apoptosis by oncogenic Raf-1. Additionally, we also could extend these findings to the IL-3-dependent pro-B-cell line BaF3, suggesting that recruitment of MEK is a common mechanism for survival signaling by activated Raf. Requirement for the PI3K effector AKT in this process is further demonstrated by the inhibitory effect of a dominant negative AKT mutant on Raf-1-induced cell survival. Moreover, a constitutively active form of AKT synergizes with Raf-1 in apoptosis suppression. In summary these data strongly suggest a Raf effector pathway for cell survival that is mediated by MEK and AKT.
The KRAB domain of human Kox1, a member of the KRAB C2H2 zinc finger family, confers strong transcriptional repressor activities even to remote promoter positions. Here, HDAC inhibitors were used to demonstrate that histone deacetylation is not required for mediating transcriptional repression of KRAB zinc finger proteins. Two reporter systems with either stably integrated or transiently transfected templates, both under control of strong viral promoters, were analyzed. Under all circumstances, HDAC inhibition did not alter the repression potential of the KRAB domain. In case of the stably integrated luciferase reporter gene system, neither expression levels of the KRAB fusion protein nor complex formation with its putative co-repressor TIF1beta were significantly changed. Furthermore, the TIF1beta/KRAB complex was devoid of mSin3A and HDAC1. In the transient transfection system, the transcriptional repression induced by TIF1beta and HP1alpha was not diminished by HDAC inhibitors, whereas the repressory activity of TIF1alpha was significantly affected. Thus, KRAB, TIF1beta and HP1alpha are likely to be functionally linked. In conclusion, HDAC activity is not essential for the strong transcriptional repressor activity mediated by the KRAB domain of Kox1 in particular and, presumably, by KRAB domains in general. This feature might be helpful in identifying and characterizing target genes under the control of
Multidrug resistance pumps (MDRs) protect microbial cells from both synthetic and natural antimicrobials. Amphipathic cations are preferred substrates of MDRs. Berberine alkaloids, which are cationic antimicrobials produced by a variety of plants, are readily extruded by MDRs. Several Berberis medicinal plants producing berberine were found also to synthesize an inhibitor of the NorA MDR pump of a human pathogen Staphylococcus aureus. The inhibitor was identified as 5'-methoxyhydnocarpin (5'-MHC), previously reported as a minor component of chaulmoogra oil, a traditional therapy for leprosy. 5'-MHC is an amphipathic weak acid and is distinctly different from the cationic substrates of NorA. 5'-MHC had no antimicrobial activity alone but strongly potentiated the action of berberine and other NorA substrates against S. aureus. MDR-dependent efflux of ethidium bromide and berberine from S. aureus cells was completely inhibited by 5'-MHC. The level of accumulation of berberine in the cells was increased strongly in the presence of 5'-MHC, indicating that this plant compound effectively disabled the bacterial resistance mechanism against the berberine antimicrobial.
Phosphorothioate oligodeoxynucleotides (P=S ODNs) are frequently used as antisense agents to specifically interfere with the expression of cellular target genes. However, the cell biological properties of P=S ODNs are poorly understood. Here we show that P=S ODNs were able to continuously shuttle between the nucleus and the cytoplasm and that shuttling P=S ODNs retained their ability to act as antisense agents. The shuttling process shares characteristics with active transport since it was inhibited by chilling and ATP depletion in vivo. Transport was carrier-mediated as it was saturable, and nuclear pore complex-mediated as it was sensitive to treatment with wheatgerm agglutinin. Oligonucleotides without a P=S backbone chemistry were only weakly restricted in their migration by chilling, ATP depletion and wheatgerm agglutinin and thus moved by diffusion. P=S ODN shuttling was only moderately affected by disruption of the Ran/RCC1 system. We propose that P=S ODNs shuttle through their binding to yet unidentified cellular molecules that undergo nucleocytoplasmic transport via a pathway that is not as strongly dependent on the Ran/RCC1 system as nuclear export signal-mediated protein export, U-snRNA, tRNA and mRNA export. The shuttling property of P=S ODNs must be taken into account when considering the mode and site of action of these antisense agents.
B cell neoplasias descending from germinal center cells harbor the hallmark of intraclonal diversity resulting from ongoing mutation in the variable parts of their immunoglobulin-encoding genes. To characterize a primary cutaneous follicle center B cell lymphoma in more detail, we analyzed the respective VH and VL genes in single cells mobilized from four sequential biopsies, three taken from the skin and one obtained after internal dissemination from a retrobulbar infiltrate. The lymphoma cells were found to contain V5-51/D6-12/JH5b (heavy chain) and A27/Jkappa2 (light chain) gene rearrangements detected on both the genomic and the transcriptional level. To provide an accurate mutation analysis, the specific VH gene counterpart (V5-51UK) was cloned from the patient's germline. Analyzing 226 single cells, we found: (i) complete nucleotide identity when VH and VL genes of lymphoma cells from one particular biopsy were compared among each other; (ii) intraclonal diversity due to ongoing mutation comparing the sequences obtained from sequential biopsies; (iii) both VH and VL genes to be highly mutated. Deducing from the sequence data, we propose a scenario of the clonal evolution of the B cell tumor in this patient. From the molecular-biological point of view, this primary cutaneous follicle center B cell lymphoma shows the features of a germinal center cell lymphoma. To draw this conclusion from single cell PCR data, however, a sample of sequential biopsies had to be analyzed.
A new method of bioactivity-directed fractionation, based on multidrug resistant pump (MDR) inhibition in Staphylococcus aureus, was demonstrated. This resulted in the isolation, from berberine-containing Berberis species, of two compounds that are themselves devoid of S. aureus antibacterial activity, but that form potent synergistic couples with a subinhibitory concentration of berberine. The bacterial MDR pump inhibitors were identified as the flavonolignan 2 and the porphyrin 3. Another natural flavonolignan, silybin (8) from Silybum marianum, was also shown to be a bacterial MDR pump inhibitor.
OBJECTIVE: To determine whether homeopathic Arnica can reduce postoperative haematomas in venous surgery. DESIGN: Randomized, prospective, multicentric, double-blind placebo-controlled trial. PARTICIPANTS: 130 consecutive patients undergoing saphenous stripping (204 legs), hospitalized in a clinic. INTERVENTIONS: A homeopathic medicine (Arnica CH5) and an indistinguishable placebo, administered sublingually by a nurse the night before and immediately after the operation. OUTCOME MEASURES: Clinical evaluation of haematomas 6 days postoperatively. RESULTS: Groups were well matched (sex, age, history of bleeding or thrombosis, drug intake, previous intake of homeopathic drugs, type of operation and anaesthesia, operator). One drop-out has been replaced. No statistically significant difference in postoperative haematomas was found between the Arnica and placebo groups (p = 0.342). Subanalysis of all other items did not reveal any statistical difference either. CONCLUSIONS: In this study, with this dosage, we did not observe any preventive effect of homeopathic Arnica CH5 on poststripping haematomas.
Protein kinase CK2 is a pleiotropic Ser/Thr kinase occurring as alpha2beta2, alpha'2beta2, or alphaalpha'beta2 tetramers. A requirement in serum-stimulated cell cycle entry in both the cytoplasm and the nucleus of human fibroblasts for phosphorylation(s) by CK2 has been concluded from stimulation inhibition by microinjected antibodies against the regulatory subunit (beta). We have now examined this idea more directly by microinjection-mediated perturbation of phosphorylation and non-phosphorylation interactions of the catalytic subunits (alpha and alpha'), and by verifying the supposed matching of the cellular partition of CK2 subunits in the fibroblasts employed. While immunostaining and cell fractionation indicate that the partitions of subunits indeed match each other (with their predominant location in the nucleus in both quiescent and serum-stimulated cells), microinjection of substrate or pseudosubstrate peptides competing for the CK2-mediated phosphorylation in vitro resulted in significant inhibition of serum stimulation when placed into the nucleus but not when placed into the cytoplasm. Also inhibitory were nuclear but not cytoplasmic injections of antibodies against alpha and alpha' that affect neither their kinase activity in vitro nor their complexing to beta. The data indicate that the role played by CK2 in serum-stimulated cell cycle entry is predominantly nuclear and more complex than previously assumed, involving not only phosphorylation but also experimentally separable non-phosphorylation interactions by the catalytic subunits.
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A new amide of threo-gamma-hydroxyglutamic acid, justiciamide, was isolated from Justicia ghiesbreghtiana and shown to be (-)-N-(2-hydroxy-4,5-dimethoxyphenyl)-(2 S,4 S)-gamma-hydroxyglutamic acid. Justiciamide is the first amide of an uncommon amino acid found in this genus.
Three trace alkaloids from Colorado blue spruce, Picea pungens, were identified by synthesis and GC-MS comparisons as 4alpha-hydroxy-cis-2-methyl-6-(2-oxopropyl)piperidine (1), 4alpha-hydroxy-cis-2-methyl-6-propylpiperidine (11), and 1-methylgranatanone (15) (N-methyl-9-aza-1-methylbicyclo[3.3. 1]nonane or N-methyleuphococcinine). Alkaloids 1 and 11 are the first among numerous known pine and spruce piperidines to contain a ring-oxygenated substituent.
B cells in skin lesions of a pleomorphic cutaneous T-cell lymphoma with reactive germinal center hyperplasia were analyzed for their immunoglobulin V(H)DJ(H) gene rearrangements by micromanipulation and single cell polymerase chain reaction (PCR) analysis. In B lymphocytes located in germinal center-like structures, we found in 11/16 different V(H)DJ(H) rearrangements completely unmutated VH genes, suggesting that those cells did not undergo antigen-driven selection. Two V(H) genes showed more than 98% germ-line identity. In only three cells V(H) segments were somatically mutated to a higher extent, but two of these rearrangements were non-productive. These results differ markedly from what we have previously detected in B cells present in mycosis fungoides, another entity of cutaneous T-cell lymphomas where the Ig gene repertoire resembles the situation in peripheral blood with a significantly higher proportion of mutated V(H) genes. When investigating the large atypical B cells strongly expressing CD30 which were detected within the T-cell zone outside the germinal centers, we found again, in most cases, that the rearranged VH genes were completely unmutated. The B cells were of polyclonal origin. Due to this comparable Ig gene repertoire and mutational pattern, we suggest that these cells descend from the germinal center centroblasts which migrated into the T-cell zone and obviously became stimulated to express the CD30 marker. The micromanipulation technique and molecular analysis on the single cell level may provide an important input into our understanding of the mechanisms of immune regulation in cutaneous lymphomas.
We report on 3 sporadic cases of in utero onset megalencephaly. Children were born to healthy nonconsanguineous parents after uneventful pregnancies. Head circumferences were just above the 97th centile at birth in 2 patients, 2 cm above the 97th centile in 1 patient, and subsequently increased to 4.5-6.5 cm above the 97th centile at age 5 years. All patients completely lacked motor and speech development and showed very little intellectual progress. There was a distinctive facial aspect with frontal bossing, low nose bridge, and large eyes, but no cutaneous abnormalities and no signs of other organ involvement. Magnetic resonance imaging showed bilateral megalencephaly with a broad corpus callosum, enlarged white matter, and focally thick gray matter, resulting in pachygyric appearance of the cortex. Opercularization was incomplete, and the Sylvian fissures were wide. Somatosensory evoked potentials in 1 patient showed normal latencies of cervical and contracortical potentials but bilaterally increased cortical amplitudes. To the best of our knowledge, no similar case observations have been recorded previously.