Annular leukocytoclastic vasculitis in association with chronic hepatitis B.
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Aged↗
Biomedical subjects
M Meissner
Publications and source records attributed to M Meissner.
Expression and function of the gene encoding the voltage-dependent calcium channel beta3-subunit in the mouse placenta.
Voltage-dependent Ca(2+) channels (VDCC) exist in most excitable cells and their properly regulated activity is essential for critical biological processes as many of these are sensitive to cellular Ca(2+) ion concentration. The ancillary cytoplasmic Ca(2+) channel beta subunits (CACNB) modulate Ca(2+) channel function and are required to enhance the number of functional channels in the plasma membrane. There are four genes encoding CACNB subunits and the gene encoding CACNB3 is over expressed in hyperplastic placentas of mouse interspecies hybrids. To determine the role of CACNB3 in the mouse placenta, we performed an expression and function analysis. Our results show that Cacnb3 exhibits specific spatial and temporal expression in the mouse placenta. Deletion of Cacnb3 does not produce a strong placental phenotype, which may be due to expression of other CACNB subunit encoding genes; however, sporadic occurrence of a labyrinthine architecture phenotype, characterized by reduced density of fetal blood vessels and decrease in pericyte number, could be observed. Down-regulation of Cacnb3 expression did not rescue placental hyperplasia in a model of interspecies hybrid placentas, which indicates that up-regulation in the hyperplastic placentas is a downstream event.
Animals↗
Suberythrodermic pustular psoriasis induced by clopidogrel.
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Aged↗
Sodium thiosulphate as a promising therapeutic option to treat calciphylaxis.
A 35-year-old haemodialysis-dependent woman with chronic renal failure developed large, very painful necrotic ulcers and necrosis on the thighs, buttocks and the abdomen with signs of fast progression. The skin biopsy specimens showed a broad necrosis of the epidermis and thrombosed dermal vessels with focal calcium deposits within the wall. In addition, laboratory findings presented an increased product of serum calcium and phosphate concentrations. Thus, we diagnosed calciphylaxis on the basis of clinical, biochemical and histopathological criteria. We initiated a therapy in which our patient was treated with intravenous sodium thiosulphate 3 times weekly. Already after 2 weeks of treatment, no new lesions were detectable and there was a dramatic pain relief. In the following 4 weeks, a successive decline of the ulcers and the healing of individual tissue defects could be seen. Four months after the start of the therapy, the patient underwent successful renal transplantation. Thus, the intravenous therapy of calciphylaxis with sodium thiosulphate might be a new effective alternative in the treatment of this life-threatening disease.
Abdomen↗
Neutron scattering study of the field-dependent ground state and the spin dynamics in spin-one-half NH4CuCl3.
Elastic and inelastic neutron scattering experiments have been performed on the dimer spin system NH4CuCl3, which shows plateaus in the magnetization curve at m=1/4 and m=3/4 of the saturation value. Two structural phase transitions at T1 approximately 156 K and at T(2)=70 K lead to a doubling of the crystallographic unit cell along the b direction and as a consequence a segregation into different dimer subsystems. Long-range magnetic ordering is reported below T(N)=1.3 K. The magnetic field dependence of the excitation spectrum identifies successive quantum phase transitions of the dimer subsystems as the driving mechanism for the unconventional magnetization process in agreement with a recent theoretical model.
Journal Article↗
[Adrenal adenomatoid tumor. A rare clinicopathological entity].
Adenomatoid tumors are uncommon, benign tumors of the genital tract which have also been reported to occur extragenitally. Case reports on adenomatoid tumors of the adrenal gland exist. Most of these are incidentally discovered at autopsy or after the resection of incidentalomas. We report on the case of a young man with epigastic pain and with the finding of a 4 cm heterogeneous right adrenal mass on abdominal CT scan. After endocrine activity had been ruled out, an inactive, benign adrenal tumor was suspected and laparoscopic right adrenalectomy performed. The specimen was found to be an adenomatoid tumor. We discuss the differential diagnosis and the possible embryological origin of these tumors. The feature of 'local invasive ability' does not imply malignancy. All cases discovered surgically and at autopsy have been benign. Local resection seems to be the appropriate therapy.
Adenomatoid Tumor↗
Deep venous thrombosis: rate of spontaneous lysis and thrombus extension.
AIM: Although recanalization occurs after an episode of venous thrombosis, the exact timing for this process, the rate of clearing at the different venous segments and the nature of the mechanisms involved and their progression are not well known. Recognition of these competing events is important in understanding the natural history and the mechanisms responsible for lysis of the thrombus and for the development of the post-thrombotic syndrome METHODS: During the course of 5 consecutive years, 110 patients (126 legs) with deep vein thrombosis (DVT) were prospectively followed using ultrasonic duplex. Follow-up studies were performed at intervals of 1 and 7 days, 1 month, every 3 months for the 1(st) year, and yearly thereafter. Mean duration of follow-up was 329 days. RESULTS: When only legs with initial complete occlusion are considered, the prevalence of occlusion progressively decreases to 33% after 6 months, 17% after the 1(st) year, and 0% after 3 years. Recanalization of individual segments occurred even more rapidly. After 3 months, recanalization of completely occluded segments was present in 93% of common femoral veins, 79% of superficial femoral veins (proximal segment), 84% of popliteal veins, and 72% of posterior tibial veins. The rate of recanalization was highest for multisegmental disease. Propagation of thrombi to adjacent venous segments occurred in 15% of the limbs. Propagation was usually limited to 1 or 2 adjacent segments. CONCLUSION: Lysis occurred early and was progressive. After 1 year most legs have recanalized. After 3 years recanalization occurred in all legs although residual thrombosis (partial obstruction) was still present in 50% of the limbs. Propagation of the thrombus was a limited process.
Adolescent↗
Modulation of myosin A expression by a newly established tetracycline repressor-based inducible system in Toxoplasma gondii.
We have developed a control system for regulating gene activation in Toxoplasma gondii. The elements of this system are derived from the Escherichia coli tetracycline resistance operon, which has been widely used to tightly control gene expression in eukaryotes. The tetracycline repressor (tetR) interferes with transcription initiation while the chimeric transactivator, composed of the tetR fused to the activating domain of VP16 transcriptional factor, allows tet-dependent transcription. Accordingly, tetracycline derivatives such as anhydrotetracycline, which we found to be well tolerated by T.gondii, can serve as effector molecules, allowing control of gene expression in a reversible manner. As a prerequisite to functionally express the tetR in T.gondii, we used a synthetic gene with change of codon frequency. Whereas no activation of transcription was achieved using the synthetic tetracycline-controlled transactivator, tTA2(s), the TetR(s )modulates parasite transcription over a range of approximately 15-fold as measured for several reporter genes. We show here that the tetR-dependent induction of the T.gondii myosin A transgene expression drastically down-regulates the level of endogenous MyoA. This myosin is under the control of a tight feedback mechanism, which occurs at the protein level.
Animals↗
Excitations of the field-induced quantum soliton lattice in CuGeO(3).
The incommensurate magnetic soliton lattice in the high-field phase of a spin-Peierls system results from quantum fluctuations. We have used neutron scattering techniques to study CuGeO(3), allowing us to obtain the first complete characterization of the excitations of the soliton lattice. Three distinct excitation branches are observed, all of which are gapped. The two highest energy modes have minimum gaps at the commensurate wave vector and correspond to the creation or annihilation of soliton pairs. The third mode is incommensurate and is discussed in relation to theoretical predictions.
Journal Article↗
Choice of venous cannulation for bypass during repair of traumatic rupture of the aorta.
BACKGROUND: Choices for venous cannulation for left heart bypass, to assist repair of traumatic rupture of the thoracic aorta, are between the left atrial appendage and pulmonary veins. METHODS: A retrospective chart review was performed of patients who underwent operative repair of ruptured aorta. RESULTS: Over a 15-year period between March 1985 and February 2000, 133 patients were admitted to a level I trauma center with aortic rupture. Of the 50 procedures performed with left heart bypass, the left atrial appendage was cannulated in 19 and pulmonary veins in 31 (four superior, 27 inferior). Complications occurred in 7 of the 19 patients who underwent venous cannulation via the atrial appendage (two ventricular fibrillation, three atrial fibrillation, one pericardial effusion leading to tamponade, and one phrenic nerve injury). Complications occurred in 2 patients who underwent cannulation via pulmonary vein (one atrial fibrillation, one pericardial effusion requiring tapping) (p = 0.02). CONCLUSIONS: Cannulation via the pulmonary veins is associated with a decrease in complication rates compared with cannulation of the atrial appendage.
Adult↗
RNA polymerase I holoenzyme-promoter complexes include an associated CK2-like protein kinase.
In eukaryotes, RNA polymerase I (pol I) transcribes the tandemly repeated genes that encode the precursor of 18S, 5.8S and 25S ribosomal RNAs. In plants and animals, the pol I enzyme can be purified in a holoenzyme form that is self-sufficient for promoter binding and accurate, promoter-dependent transcription in a cell-free system. In this report, we show that a casein kinase 2 (CK2)-like protein kinase co-purifies with pol I holoenzyme activity purified from broccoli (Brassica oleracea). Using an immobilized template assay, we show that the CK2-like activity is part of the protein-DNA complex that results upon binding of the holoenzyme to the rRNA gene promoter. The CK2 activity phosphorylates a similar set of holoenzyme proteins both before and after promoter binding. These data provide further evidence that pol I holoenzyme activity can be attributed to a single, multi-protein complex self-sufficient for promoter association and accurate, promoter-dependent transcription.
Brassica↗
Downregulation of the constitutive tapasin expression in human tumor cells of distinct origin and its transcriptional upregulation by cytokines.
Human tumor cells frequently exhibit abnormalities in the major histocompatibility complex (MHC) class I surface expression which can be due to structural alterations and/or dysregulation of various components of the MHC class I antigen processing machinery, such as HLA class I heavy and light chains, the peptide transporter and the proteasome subunits. Although several cofactors critical for proper MHC class I assembly have been identified, their contribution to the immune escape phenotype of tumor cells has not been analyzed. In order to determine whether tapasin deficits are an integral part of immune escape mechanisms of human tumors, we studied the constitutive and cytokine-regulated expression pattern of tapasin in malignant cells of distinct histology. Heterogeneous and reduced expression levels of tapasin were found in small-cell lung carcinoma, pancreatic carcinoma, colon carcinoma, head an neck squamous cell carcinoma and renal cell carcinoma cell lines. Tapasin downregulation was also prominent in surgically removed tumor lesions when compared to normal controls. The impaired tapasin expression is often associated with low MHC class I cell surface expression. In addition, various cytokines, including interferon (IFN)-alpha, IFN-gamma, tumor necrosis factor (TNF)-alpha and interleukin (IL)-4, but not granulocyte-macrophage colony stimulating factor (GM-CSF), transcriptionally upregulate to a distinct extent and in a time-dependent manner tapasin expression in tumor cells. Thus, deficient tapasin expression appears to be a frequent event in human tumor cells. Its restoration by cytokines further suggests that impaired tapasin expression in tumors is rather due to dysregulation than to structural alterations.
Antiporters↗
Anatomical considerations in the surgical management of blunt thoracic aortic injury.
PURPOSE: Blunt aortic injury (BAI) involving the thoracic aorta is usually described as occurring at the isthmus. We hypothesized that injuries 1 cm or less from the inferior border of the left subclavian artery (LSCA) are associated with an increased mortality rate compared with injuries that are more distal. METHODS: A retrospective review of patients admitted with the diagnosis of BAI was performed. Injuries were divided into two groups: group I, injuries that were 1 cm or less from the junction of the LSCA and the thoracic aorta; group II, injuries that were more than 1 cm from the LSCA. Primary outcome measures included cross-clamp time, rupture, and death. RESULTS: In a 14-year period, 122 patients were admitted with BAI. The anatomy relative to the LSCA could be determined in 91 patients who underwent operative repair. Forty-two injuries (46%) were classified as group I, and 49 injuries were classified as group II. Group I injuries were characterized by an increased mortality rate (18/42 or 43% in group I vs 11/49 or 22% in group II, P = .04), intraoperative rupture rate (7/42 or 17% in group I vs 1/49 or 2% in group II, P = .003), and cross-clamp time (39.5 +/- 21.9 minutes in group I vs 28.4 +/- 13 minutes in group II, P = .04). Three ruptures occurred while proximal control was being obtained. CONCLUSION: Increased technical difficulty and risk of rupture characterize injuries that occur proximally in the descending thoracic aorta, 1 cm from the LSCA. These injuries may be better managed by instituting bypass before attempting to obtain proximal control and by routinely clamping proximal to the LSCA.
Analysis of Variance↗
hNMP 200: a novel human common nuclear matrix protein combining structural and regulatory functions.
Previously we have reported about human nuclear matrix proteins (hNMPs) with increased reassembling and potential filament-forming capability [C. Gerner et al., 1999, J. Cell. Biochem. 74, 145-151]. Here, we cloned the cDNA of one of these proteins, hNMP 200, following partial amino acid sequencing of the novel 56-kDa nuclear protein. Sequence alignments show hNMP 200-related proteins in metazoans, plants, and yeast, the homologous Saccharomyces cerevisiae protein prp19 being an accessory, but essential, factor for pre-mRNA processing. Evidence for any enzymatic activity was not detected. However, the hNMP 200 primary sequence contained five consensus WD-repeat sequences, indicative of participation and regulatory function in larger protein assemblies. Northern blot analysis and 2D protein electrophoresis showed ubiquitous expression of hNMP 200 in a variety of cell types. (35)S labeling studies indicated a high metabolic stability of the protein. The hNMP 200 gene was assigned to chromosomal region 11q12.2. Confocal laser scanning microscopy revealed that the intracellular localization conformed with that reported for other structural nuclear proteins. In interphase cells, green fluorescent protein-tagged hNMP 200 was predominantly nucleoplasmic. Structures with speckled appearance extended through several sections of in situ-isolated nuclear matrices. During cell division hNMP 200 became irregularly distributed in prophase, sparing regions of condensing chromatin. In anaphase it was concentrated in the spindle midzone. The putative dual function of the novel NMP is discussed. Being a component of the nuclear framework, it may provide structural support for components of the RNA-processing machinery, thereby also modulating splicing activities.
Amino Acid Sequence↗
Polytrauma induces increased expression of pyruvate kinase in neutrophils.
Polytrauma (PT) leads to systemic activation of polymorphonuclear neutrophils (PMNs). Organ damage commonly found in these patients is ascribed to respiratory bursts of activated PMNs. With the use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, PMN extracts from PT patients were found to contain a clear protein band not seen in control PMNs from healthy volunteers. This band was identified by amino acid sequencing and Western blotting as pyruvate kinase (PK). Enzymatic assays revealed a 600-fold increase in PK activity in PMNs of PT patients, with the highest levels occurring between the fifth and seventh posttraumatic day. In lymphocytes, no such increase was detectable. As PK is a major regulatory enzyme in glycolysis, glucose-dependent lactate production in PMNs from PT patients was assayed. These cells showed a higher glycolytic lactate production than controls. It was additionally demonstrated that acute activation of respiratory burst activity depends mainly on breakdown of glucose to lactate via the pentose-phosphate pathway and glycolysis. In PMNs from PT patients, this glucose-dependent respiratory burst activity was more than twofold higher than in controls. The increase in expression and activity of PK in PMNs from PT patients may contribute to the high glucose-dependent respiratory burst activity seen in these cells.
Adult↗
Intravenous immunoglobulin therapy in a patient with lupus serositis and nephritis.
The use of intravenous immunoglobulin (IVIg) has been reported as an immunomodulating agent in several autoimmune diseases, including systemic lupus erythematosus (SLE). Herein we report a SLE patient with severe clinical presentation that included pericarditis, pleural effusion, nephrotic range proteinuria, leukopenia, and lymphopenia. The patient received one course of high-dose IVIg (2.8 g/kg body weight), and within a week of post-IVIg therapy, her condition significantly improved. One-month post-IVIg there were decreased proteinuria, elevated leukocytes and lymphocytes count, decrease in antinuclear and anti-dsDNA antibodies, and disappearance of pericarditis and pleuritis. This case demonstrates the efficacy of IVIg in severe SLE with various clinical manifestations.
Adult↗
New ultrasound approaches to dialysis access monitoring.
The failure of dialysis access is a frequent source of morbidity and hospitalization. Traditional methods of graft surveillance include: (1) clinical examination, (2) venous line pressure measurements during dialysis, (3) urea or tracer recirculation measurement, (4) continuous wave (CW) Doppler methods, (5) duplex ultrasonography, and (6) radiograph angiography. All these methods require special training and/or laboratory tests. The purpose of this study was to test a simple continuous-wave Doppler method that could be applied to measure the flow rate in dialysis access every time the patient undergoes dialysis. Twenty dialysis patients, 15 with polytetrafluoroethylene grafts and 5 with arteriovenous fistulae, were studied. Two hundred fifty-three examinations were performed over an 8-month period. Doppler waveforms of the access flow were obtained with the pump on, with the pump off, and with the pump on again. Systolic and diastolic Doppler frequency measurements were made, and the pump-on and pump-off measurements were compared. In an access functioning normally, the Doppler frequencies are higher with the pump off than with the pump on. In 22% of the cases, there were abnormal findings in which the Doppler frequencies were lower with the pump off than with the pump on. This occurs if the needles are incorrectly placed, suggesting that recirculation is occurring. Recirculation also occurs if there is stenosis of the access. Examining the hemodialysis access during each dialysis session with an inexpensive directional Doppler may identify a significant stenosis and improve the efficiency of dialysis by detecting those patients in whom the arterial and venous needles are reversed.
Adult↗
The fate of the nuclear matrix-associated-region-binding protein SATB1 during apoptosis.
Special AT-rich sequence-binding protein 1 (SATB1), predominantly expressed in thymocytes, was identified as a component of the nuclear matrix protein fraction. Programmed cell death of Jurkat T-cells was induced by various stimuli in Fas-dependent and -independent fashion. During apoptosis, but not during necrosis, SATB1 was cleaved, as rapidly as was lamin B, in a caspase-dependent way yielding a stable 70 kDa fragment. The same result was obtained for apoptotic HL60-cells. We constructed various deletion constructs of SATB1, expressing protein chimeras tagged with green fluorescent protein (GFP). Transient transfection of these into Jurkat or HeLa cells followed by initiation of apoptosis allowed us to map the potential caspase-6 cleavage site VEMD to the N-terminal third of SATB1, leaving an intact DNA-binding domain in the C-terminal part of the protein. Our results suggest that apoptosis-specific breakdown of SATB1, a transcriptional activator of the CD8a gene, might be of physiological relevance during thymic clonal deletion and apoptosis of peripheral T-lymphoid cells.
Amino Acid Sequence↗