Search PubMed⌕ Search

Biomedical subjects

H Barth

Publications and source records attributed to H Barth.

At least 19 recordsLinked to original sources
PubMed2005

In vitro study on the immunological effect of bromelain and trypsin on mononuclear cells from humans.

BACKGROUND: Proteolytic enzymes such as bromelain and trypsin are used as an adjuvant therapeutic approach in the treatment of chronic inflammatory, malignant and autoimmune diseases. In vitro studies have shown that proteolytic enzymes modulate surface adhesion molecules on T-cells. In this study we analysed the influence of bromelain and trypsin on the cytokine production and proliferation of peripheral blood mononuclear cells (PBMC) from patients with a classical cellular mediated autoimmune disorder, namely encephalomyelitis disseminata (ED) as well as from healthy controls. - METHODS: PBMC from patients with ED (n=12) and healthy controls (n=12) were cultured for seven days at 37 degrees C under three different conditions: without antigen, with bromelain and with trypsin (final concentrations 10-1000 microg/ml). Proliferation was determined by superset3H-thymidine incorporation. Secretion of cytokines into the supernatant was measured by a double sandwich ELISA. Intracellular cytokines were determined by flow cytometric analysis. - RESULTS: PBMC from patients with ED and healthy controls showed a significantly increased proliferative response to bromelain (ED: 14053+/- 7585 cpm with bromelain vs. spontaneous proliferation of 430+/- 255 cpm; healthy controls: 10689+/- 4607 cpm vs. 327+/-193) but not to trypsin. Bromelain induced in all 24 individuals a significant increase of the macro-phage/monocyte associated cytokines interleukin (IL)-6, granulocyte-macrophage-colony stimulating factor (GM-CSF), tumour necrosis factor alpha (TNFa) (p<0.01) as well as of the type 1 cytokine gamma-interferon (IFNgamma). In contrast, the type 2 cytokines IL-4 and IL-5 were not induced. Flow cytometric analysis revealed a significant increase of IFNgamma-producing CD4+ T-cells. There were no differences in cytokine production between ED patients and healthy controls. - CONCLUSION: These results indicate that bromelain - but not trypsin - activates macrophages/monocytes and type 1 cells independently from the underlying disease and may stimulate, therefore, the innate as well as the adaptive immune system.

Adult↗
PubMed2005

Unusual locations for cavernous hemangiomas: report of two cases and review of the literature.

Cavernous hemangiomas are most commonly found within the subcortical neural parenchyma near the fissura Rolandi, in the basal ganglia, or in the brain stem. Because of advancing neuro-imaging technology and thus resulting in a higher incidence of cavernous hemangiomas they have rising impact in neurosurgery. We present two unusual cases of extra-axial cavernous hemangiomas: one located at the frontal falx, the other within the bone of the right frontal bone. We discuss these and other cases in the literature with respect to the more common differential diagnoses and the appropriate therapy regimen for cavernous hemangiomas in these locations.

Adult↗
PubMed2005

Genetic variants of hepatitis B virus and their clinical relevance.

Infection with hepatitis B virus (HBV) leads to a wide spectrum of clinical presentations ranging from an asymptomatic carrier state to self-limited acute or fulminant hepatitis to chronic hepatitis with progression to cirrhosis and hepatocellular carcinoma (HCC). Infection with HBV is one of the most common viral diseases affecting man. Both viral factors as well as the host immune response have been implicated in the pathogenesis and clinical outcome of HBV infection. Evidence has been accumulating that HBV mutants are associated with certain clinical disease manifestations, may affect the natural course of the infection and confer resistance to antivirals. Naturally occurring mutations have been identified in the structural and non-structural genes as well as regulatory elements of the virus. The best characterized mutants comprise the pre-core (pre-C) stop codon mutation resulting in a loss of hepatitis B e antigen (HBeAg), defined clusters of mutations in the core promotor resulting in enhanced viral replication and mutations in the hepatitis B core and surface antigens (HBcAg and HBsAg) altering the antigenicity of the virus. More recently, several mutations in the reverse transcriptase/polymerase gene have been identified conferring resistance to antivirals used for the treatment of chronic hepatitis B. In this review, we will focus on the biological phenotype of HBV genetic variants and discuss their clinical relevance for the pathogenesis of HBV-induced liver disease.

Antiviral Agents↗
PubMed2004

Uptake of binary actin ADP-ribosylating toxins.

The focus of this article is on the cellular uptake mechanism of the family of binary actin ADP-ribosylating toxins from clostridia. These toxins are special-type AB toxins, because they are composed of two nonlinked proteins, which have to assemble on the surface of eukaryotic cells to act cytotoxically. The enzymatically active component (A), ADP-ribosylates G-actin in the cytosol of target cells. This leads to a complete depolymerization of the actin filaments and, thereby, to rounding up of cultured cells. The second component of these toxins, the binding/translocation component (B), mediates the transport of the enzyme component into the cytosol.

Actins↗
PubMed2004

The small GTPase Rac is involved in clustering of hippocampal neurons and fasciculation of their neurites.

In hippocampal neurons cultured from brains of newborn rats, the glutamate receptor agonist N-methyl-D-aspartate induced the clustering of neuronal perikarya and the fasciculation of neurites. In addition, N-methyl-D-aspartate activated the small GTPase Rac1. Other stimuli of Rac activity, such as the Rho kinase inhibitors Y-27632, H-1152, and H89, as well as the cytotoxic necrotizing factor-1 from Escherichia coli, also caused neuronal clustering and neurite bundling. In neurons transiently transfected with dominant negative Rac1N17 neither N-methyl-D-aspartate nor Y-27632 induced clustering and fasciculation. In addition, the PI3-kinase inhibitors wortmannin and LY-294002 prevented these effects, as did a dominant negative form of p110PI3-Kgamma. Time-lapse microscopy showed that lethal toxin from Clostridium sordellii, which inhibits Rac, and wortmannin blocked the neuronal migration induced by Y-27632. In contrast, only lethal toxin reversed the clustering and fasciculation induced by pre-treatment with Y-27632. This effect of the toxin may be due to inactivation of Ras, since FTI-277, which prevents the farnesylation of Ras and thereby inactivates the GTPase, also dissolved the preformed clusters. We suggest that active Rac and a PI3-kinase synergistically induce neuronal migration, whereas a Ras isoform is responsible for the lasting attachment of neurons necessary for clustering and neurite fasciculation.

Amides↗
PubMed2004

cAMP protects endothelial barrier functions by preventing Rac-1 inhibition.

cAMP enhances endothelial barrier properties and is protective against various inflammatory mediators both in vivo and in vitro. However, the mechanisms whereby cAMP stabilizes the endothelial barrier are largely unknown. Recently we demonstrated that the Rho family GTPase Rac-1 is required for maintenance of endothelial barrier functions in vivo and in vitro. Therefore, in the present study we investigated the effect of forskolin (5 microM)- and rolipram (10 microM)-induced cAMP increase on reduction of barrier functions in response to Rac-1 inhibition by Clostridium sordellii lethal toxin (LT). Forskolin and rolipram treatment blocked LT (200 ng/ml)-induced hydraulic conductivity (Lp) increase in mesenteric microvessels in vivo. Likewise, LT-induced intercellular gap formation in monolayers of cultured microvascular myocardial endothelial (MyEnd) cells and LT-induced loss of adhesion of vascular endothelial cadherin-coated microbeads were abolished. Inhibition of PKA by myristoylated inhibitor peptide (14-22) of PKA (100 microM) reduced the protective effect of cAMP on LT-induced Lp increase in vivo and gap formation in vitro, indicating that the effect of cAMP on Rac-1 inhibition was PKA dependent. Glucosylation assays demonstrated that cAMP prevents inhibitory Rac-1 glucosylation by LT, indicating that one way that cAMP enhances endothelial barrier functions may be by regulating Rac-1 signaling. Our study suggests that cAMP may provide its well-established protective effects at least in part by regulation of Rho proteins.

Animals↗
PubMed2004

[Benign fibro-osseous tumors of the frontal skull base with intracranial extension. Report of 2 cases].

We report on two patients with ossifying fibroma of the anterior skull base with intracranial extension. A psammomatoid ossifying fibroma was removed from a 29 year old female patient, and in a 37 year old female patient a cemento ossifying fibroma was removed. The main clinical symptom in both cases was headache. Surgery took place after diagnosis and therapy in an interdisciplinary operation with ENT colleagues. The ossifying fibroma is a benign neoplasm mainly affecting the maxilla and mandible. Complete removal is better than a curettage of the tumor.

Adult↗
PubMed2004

Study of clinical features of amyloid angiopathy hemorrhage and hypertensive intracerebral hemorrhage.

OBJECTIVE: The purpose of this study was to differentiate between cerebral amyloid angiopathy (CAA) and hypertension (HTN) based on hemorrhage pattern interpretation. METHODS: From June 1994 to Oct., 2000, 83 patients admitted to our service with acute intracerebral hemorrhage (ICH) were investigated retrospectively; 41 patients with histologically proven diagnosis of cerebral amyloid angiography and 42 patients with clear history of hypertension were investigated. RESULTS: Patients with a CAA-related ICH were significantly older than patients with a HTN-related ICH (74.0 years vs 66.5 years, P < 0.05). There was a significantly higher number of hematomas > or = 30 ml in CAA (85.3%) when compared with HTN (59.5%). No basal ganglional hemorrhage was seen in CAA, but in 40.5% in HTN. In CAA-related ICH, subarachnoid hemorrhage (SAH) was seen in 26 patients (63.4%) compared to only 11 patients (26.2%) in HTN-related ICH. Intraventricular hemorrhage was seen in 24.4% in CAA, and in 26.2% in HTN. Typical features of CAA-related ICH included lobar distribution affecting mainly the lobar superficial areas, lobulated appearance, rupture into the subarachnoid space, and secondary IVH from the lobar hemorrhage. More specifically, multiplicity of hemorrhage, bilaterality, and repeated episodes also strongly suggest the diagnosis of CAA. Multiple hemorrhages, defined as 2 or more separate hematomas in multiple lobes, accounted for 17.1% in CAA-related ICH. CONCLUSION: There are certain features in CAA on CT and MRI and in clinical settings. To some extent, these features may contribute to distinguishing CAA from HTN related ICH.

Adult↗
PubMed2004

High efficacy and minor renal effects of indomethacin treatment during individualized fluid intake in premature infants with patent ductus arteriosus.

AIM: To determine the efficacy and the renal side effects of indomethacin treatment for closure of a patent ductus arteriosus (PDA) in premature infants during an individualized fluid regime that avoids hypovolaemia and subsequent prostaglandin-dependent renal perfusion. METHODS: Observational retrospective analysis of the efficacy of indomethacin in premature infants with PDA treated in a single institution from June 1992 to May 2000. The clinical course and renal effects were analysed in the subgroup of infants born from June 1995 to May 2000. The management of infants at risk and the treatment of infants with PDA followed a standardized protocol that included echocardiographic screening for PDA, indomethacin treatment before congestive failure develops (early symptomatic treatment) and an individualized fluid intake. RESULTS: In total, 412 infants with a gestational age < or = 32 wk were identified. Fifty-six infants with a PDA (14%) were treated with indomethacin [mean birthweight 936 (95% confidence interval 866-1006) g; gestational age 27.3 (26.8-27.9) wk]. Indomethacin treatment was successful in 52 infants (93%). The clinical course and renal effects were analysed in 41 infants. Most infants received three indomethacin doses of 0.2 mg kg(-1) every 12 h. Urine output transiently decreased from 5.6 (4.6-6.4) to 4.6 (3.9-5.3) ml kg(-1) (h(-1). Serum creatinine temporarily increased from 0.90 (0.83-0.98) to 1.06 (0.87-1.24)mg dl(-1). Fluid intake was 158 (148-168) ml kg(-1) d(-1) before indomethacin and decreased to 142 (131-154) ml kg(-1) d(-1). CONCLUSION: Indomethacin is very effective for closure of a PDA, even in very premature infants, and is not associated with clinically significant renal side effects.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Requirement of Rac activity for maintenance of capillary endothelial barrier properties.

Our previous experiments indicated that GTPases, other than RhoA, are important for the maintenance of endothelial barrier integrity in both intact microvessels of rats and mice and cultured mouse myocardial endothelial (MyEnd) cell monolayers. In the present study, we inhibited the endothelial GTPase Rac by Clostridium sordellii lethal toxin (LT) and investigated the relation between the degree of inhibition of Rac by glucosylation and increased endothelial barrier permeability. In rat venular microvessels, LT (200 ng/ml) increased hydraulic conductivity from a control value of 2.5 +/- 0.6 to 100.8 +/- 18.7 x 10-7 cm x s(-1) x cm H2O(-1) after 80 min. In cultured MyEnd cells exposed to LT (200 ng/ml), up to 60% of cellular Rac was glucosylated after 90 min, resulting in depolymerization of F-actin and interruptions of junctional distribution of vascular endothelial cadherin (VE-cadherin) and beta-catenin as well as the formation of intercellular gaps. To understand the mechanism by which inhibition of Rac caused disassembly of adherens junctions, we used laser tweezers to quantify VE-cadherin-mediated adhesion. LT and cytochalasin D, an actin depolymerizing agent, both reduced adhesion of VE-cadherin-coated microbeads to the endothelial cell surface, whereas the inhibitor of Rho kinase Y-27632 did not. Stabilization of actin filaments by jasplakinolide completely blocked the effect of cytochalasin D but not of LT on bead adhesion. We conclude that Rac regulates endothelial barrier properties in vivo and in vitro by 1) modulation of actin filament polymerization and 2) acting directly on the tether between VE-cadherin and the cytoskeleton.

Actins↗
PubMed2003

Dysplastic gangliocytoma of the cerebellum: rare differential diagnosis in space occupying lesions of the posterior fossa.

Dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos) is a rare space occupying lesion of the posterior fossa with some typical neuroradiological features which can be better diagnosed in the MRI era. This is the major CNS manifestation of Cowden disease. In recent years more publications underlined the association of these hamartomatous lesions. We add another patient with a dysplastic gangliocytoma of the cerebellum who also had a thyroid adenoma and fulfilled the criteria of having Cowden disease.A problem of surgical removal of these tumors is missing the borderline between tumor and healthy cerebellum tissue so that incomplete removal of the tumor is not rare. Surgical removal of these tumors in an open MRI unit would be a good indication.

Adult↗
PubMed2003

Subarachnoid hemorrhage of unknown origin and the basilar artery configuration.

It is unclear whether the configuration of the basilar artery (BA) in patients with subarachnoid hemorrhage (SAH) of unknown origin is comparable to that in normal subjects or whether there are differences which may help to identify the origin. We studied the BA configuration in 57 patients with SAH of unknown origin (10%), who were identified in a prospectively collected series of 549 SAH patients consecutively admitted to our service over a 9-year period. There were 30 patients (53%) with non-perimesencephalic SAH and 27 with perimesencephalic SAH (47%). According to a standardized algorithm we determined, on straight anteroposterior digital subtraction angiography (DSA), the width of the proximal BA segment at the origin of the anterior inferior cerebellar artery and the width of the most distal BA segment between the superior cerebellar arteries and the posterior cerebral arteries. Based on these measurements we calculated the distal-proximal BA ratios and compared them to the ratios obtained in a control group of 31 patients who had DSA for reasons other than aneurysmal SAH. The mean ratio in patients with non-perimesencephalic SAH of unknown origin was 1.150 (range: 1.080-1.230). In patients with perimesencephalic SAH of unknown origin it was 1.156 (range: 1.120-1.250). In the control group the mean ratio was 1.163 (range: 1.125-1.200). There are no variations in the configurations of the BA which could possibly explain the cause of this type of SAH or clarify the origin of hemorrhage.

Adult↗
PubMed2003

Methods for the in vitro determination of an individual disposition towards TH1- or TH2-reactivity by the application of appropriate stimulatory antigens.

In this study we performed several methods for the determination of cytokines (RT-PCR for the demonstration of cytokine mRNA and flow cytometry for the analysis of intracellular cytokines) and compared them with a recently established test system stimulating peripheral blood mononuclear cells (PBMC) with TH1- and TH2-relevant recall antigens and analysing type 1 and type 2 cytokines by ELISA. Aim of the study was therefore to evaluate the reliability of TH1/TH2 cytokine profiles in two individuals with different types of an allergic/atopic disposition: one of them showed a strong TH1/type 1-mediated tuberculin-reaction (subject A), the other (subject B) revealed elevated IgE-levels and eosinophil counts (TH2/type 2-mediated). PBMC were incubated with the type 1-antigen purified protein derivative (PPD) and the type 2-antigen tetanus-toxoid (TT) for seven days. From the comparison of ELISA with RT-PCR and flow cytometry-analysis it became evident that all three methods allowed the definition of subject A as a 'type 1-responder'. Subject B showed a pure type 2-response in the ELISA method; PCR and flow cytometry analysis revealed the simultaneous production of type 1- and type 2-cytokines resulting in a mixed type 1/type 2-profile. Active immunization of subject A with TT at the end of the observation period of 12 months resulted in a transient shift from type 1- to a mixed type 1/type 2-profile (simultaneous PPD-induced IFN-gamma- and TT-induced IL-5 production). From this pilot study based on clear cut clinical criteria concerning either a humoral or cellular immunological reactivity towards allergens/antigens it is suggested that the determination of type 1/type 2-cytokines by ELISA in supernatants of PBMC stimulated with type 1/type 2-relevant antigens is a useful approach for a better classification of 'type1-' or 'type 2-responder'.

Adult↗
PubMed2002

Rho and rho kinase modulation of barrier properties: cultured endothelial cells and intact microvessels of rats and mice.

Previous experiments using cultured endothelial monolayers indicate that Rho-family small GTPases are involved in modulation of endothelial monolayer permeability by regulating assembly of the cellular actin filament scaffold, activity of myosin-based contractility and junctional distribution of the Ca2+-dependent endothelial cell adhesion molecule, VE-cadherin. We investigated these mechanisms using both cultured endothelial cells (from porcine pulmonary artery and mouse heart) and vascular endothelium in situ (mouse aorta, and individually perfused venular microvessels of mouse and rat mesentery). Exposure to Clostridium difficile toxin B (100 ng x ml(-1)) inactivated 50-90% of all endothelial Rho proteins within 60-90 min. This was accompanied by considerable reduction of actin filament stress fibres and junctional F-actin in cultured endothelial monolayers and in mouse aortic endothelium in situ. Also, VE-cadherin became discontinuous along endothelial junctions. Inhibition of Rho kinase with Y-27632 (30 microM) for 90-120 min induced F-actin reduction both in vitro and in situ but did not cause redistribution or reduction of VE-cadherin staining. Perfusion of microvessels with toxin B increased basal hydraulic permeability (L(p)) but did not attenuate the transient increase in L(p) of microvessels exposed to bradykinin. Perfusion of microvessels with Y-27632 (30 microM) for up to 100 min reduced basal L(p) but did not attenuate the permeability increase induced by platelet activating factor (PAF) or bradykinin. These results show that toxin B-mediated reduction of endothelial barrier properties is due to inactivation of small GTPases other than RhoA. Rho proteins as well as RhoA-mediated contractile mechanisms are not involved in bradykinin- or PAF-induced hyperpermeability of intact microvessels.

Acute-Phase Proteins↗
PubMed2002

Clinical outcome after surgery of intracranial unruptured aneurysms: results of a series between 1991 and 2001.

The clinical results of surgery for unruptured aneurysms in the Neurosurgical Department of Kiel were analyzed to further discuss whether an operative treatment can be advised. Between 1991 and 2001, 54 unruptured aneurysms in 45 patients were operated in our department. No complications occurred in 38 patients; transient complications (slight aphasia, hemiparesis, psychiatric disorders) in 4 patients; postoperative seizures in one, epidural haematoma with the need of re-operation in one, and infection in another patient. At the time of discharge, GOS was 5 in 33 patients, 4 in 12 patients. But the slight disabilities were due to the aneurysm operation only in two patients, in the other 10 patients they were caused by pre-existing concomitant diseases. The Rankin-Scale after at least 6 months was 1 (no disability) in 31 patients (37 patients investigated); 2 (slight disability) in 5, and 3 (moderate disability) in one patient. In only one of these patients, the slight disability was caused by the aneurysm operation. During a telephone interview performed between 6 months and 7 years after the operation, all patients except two (31 patients investigated) gave a positive answer to the question, whether, in case of diagnosis of an aneurysm, they would undergo an operation again. Regarding our results, we still advocate treatment of unruptured aneurysms in patients who are in stable clinical conditions, especially in young patients and in patients with unique aneurysm configurations and aneurysm sizes approaching 10 mm.

Adolescent↗
PubMed2002

Analysis of immunoregulatory T-helper cell subsets in patients with multiple sclerosis: relapsing-progressive course correlates with enhanced T H1, relapsing-remitting course with enhanced T H0 reactivity.

In this study, we analysed the recall antigen-induced cytokine production by peripheral blood mononuclear cells (PBMC) from 31 patients with multiple sclerosis (MS) with a relapsing-remitting (rr) and a relapsing-progressive (rp) course and from 40 healthy controls. Cells were stimulated with purified protein derivative (PPD; type 1 response) and tetanus toxoid (TT; type 2 response). Cytokines were determined in the supernatants by ELISA. One of the interesting findings was that healthy controls showed more frequently an IL-5 production after incubation with TT than MS-patients (68% vs.37%; p<0.01), while the type 1 reactivity was only slightly enhanced in MS patients as compared to the controls. However, within the MS patients, there was a significant difference in the incidence of the type 1 reactivity comparing patients with an rp and an rr course (60% vs. 24%; p<0.05). Furthermore, the frequency of a type 0 profile (simultaneous PPD-induced IFN-gamma and TT-induced IL-5 production) was fourfold higher in rr than in the rp patients (43% vs. 10%, p<0.05). In vitro analysis of cytokine profiles in MS could therefore be an interesting approach to evaluate the prognosis of MS (rr vs. rp) already at the beginning of the disease. Thus, it seems that the presence of a type 0 profile is a valid indicator for a favorable course, while a type 1 profile is rather associated with rp MS.

Adult↗
PubMed2001

Autophagy and the cytoplasm to vacuole targeting pathway both require Aut10p.

We here report the identification of AUT10 as a novel gene required for both the cytoplasm to vacuole targeting of proaminopeptidase I and starvation-induced autophagy. aut10Delta cells are impaired in maturation of proaminopeptidase I under starvation and non-starvation conditions. A lack of Aut10p causes a defect in autophagy prior to vacuolar uptake of autophagosomes. Homozygous aut10Delta diploids do not sporulate. Vacuolar acidification indicated by accumulation of quinacrine is normal in aut10Delta cells and mature vacuolar proteinases are present. A biologically active Ha-tagged Aut10p, chromosomally expressed from its endogenous promoter, localizes in indirect immunofluorescence microscopy in the cytosol and on granulated structures, which appear clustered around the vacuolar membrane. This localization differs from known autophagy proteins.

Amino Acid Sequence↗