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Biomedical subjects

P Müller

Publications and source records attributed to P Müller.

At least 91 records · Page 5Linked to original sources
PubMed2000

Screening for bacteriuria in patients with spinal cord lesion: dipstick test, microscopic examination and urine culture.

AIM: To investigate the positive and negative predictive values for bacteriuria of a rapid chemical dipstick procedure for leukocytes and nitrite, and a microscopic examination for leukocytes and bacteria with a urine culture being the reference in patients with spinal cord lesion (SCL). METHODS: A prospective study. Significant bacteriuria was defined as > or = 10(5) CFU/mL. The microscopic examination for leukocytes was divided in four different cut-off limits for positive results. MATERIAL: A total of 256 consecutive early morning urine samples were collected from 143 SCL patients admitted to our in-patient facility. RESULTS: One hundred and twenty-eight urine cultures revealed significant bacteriuria. Eighty-seven were infected by only one microorganism, 41 samples contained significant growth of more than one species. A total of 186 microorganisms in significant growth were identified. CONCLUSION: Three or more leukocytes should be considered as a positive result. The dipstick and microscopy tests are equally valuable, considering the single tests as well as the combinations evaluated.

Bacteria↗
PubMed2000

Initial potency of lansoprazole and omeprazole tablets on pentagastrin-stimulated gastric acid secretion-a placebo-controlled study in healthy volunteers.

BACKGROUND: The new tablet formulation of omeprazole (Losec MUPS), is thought to have a stronger acid inhibition than the previously marketed capsules. METHODS: The effects of the proton pump inhibitors lansoprazole and omeprazole tablets on pentagastrin-stimulated acid secretion were compared in Helicobacter pylori-negative healthy male volunteers (n=12). The study was placebo-controlled, crossover matched and double-blind for lansoprazole (Agopton) and placebo, and single-blind for omeprazole tablets. Gastric acid response to sub-maximal pentagastrin-stimulation (0.6 microg. h/kg b.w.) was determined from 12.5 to 14.5 h after the first and second dose of the test drugs. RESULTS: Lansoprazole 15 mg and 30 mg as well as omeprazole 20 mg tablets caused a marked decrease in gastric acid secretion, showing equipotency for 15 mg lansoprazole and 20 mg omeprazole tablets. Their efficacy, however, was lower than 30 mg lansoprazole. In addition, the inter-individual variation after omeprazole tablets was higher than following lansoprazole. Neither 7.5 mg lansoprazole nor 10 mg omeprazole tablets were clearly different from placebo on the first 2 days. The drugs were well-tolerated. No clinically relevant influence was found on either laboratory screen or cardiovascular parameters. CONCLUSION: Lansoprazole 15-30 mg shows a stronger acid inhibition and a lower inter-individual variability than the new omeprazole 20 mg tablets on days 1 and 2 of dosing.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

The transbilayer distribution of phospholipids in disc membranes is a dynamic equilibrium evidence for rapid flip and flop movement.

We studied the transbilayer redistribution of phospholipids in bovine rod outer segment membranes on thoroughly washed, Ficoll-floated osmotically intact disc vesicles; freshly prepared membranes separated from the disc stack by osmotic shock; and intact disc stacks with a permeabilized plasma membrane (A-discs, B-discs C-discs, respectively). In all cases, spin-labelled phospholipid analogues (SL-PL) with choline, serine and ethanolamine head groups (PtdCho, PtdSer and PtdEtn, respectively) were taken up into the outer leaflet of the membranes by > 90% and within less than 30 s after SL-PL addition, as deduced from the disappearance of spin-label from the suspension medium and from the specific ESR spectrum of membrane-associated spin-label. Using BSA extraction, the amount of SL-PL in the outer leaflet of the bilayer was determined. It decreased with a mean half-time of < 5 min at 25 degrees C, indicating rapid redistribution of all spin-labelled phospholipids into the inner leaflet of the disc membranes. After 1 h, PtdCho and PtdEtn were distributed almost symmetrically, whereas PtdSer was 35 : 65% (in/out). Using subsequent incubation with BSA, the outward movement (flop) of the analogues was observed directly, demonstrating that inward and outward movements proceed in thermodynamic equilibrium. No effect of N-ethylmaleimide or ATP on the redistribution could be measured, which makes it unlikely that energy-consuming translocase or flippase processes are involved in the redistribution in the dark. We reason that the solubilization zone around the photoreceptor rhodopsin may be the locus of rapid redistribution of the highly unsaturated disc phospholipid.

Adenosine Triphosphate↗
PubMed2000

Phagocytic clearance of apoptotic neurons by Microglia/Brain macrophages in vitro: involvement of lectin-, integrin-, and phosphatidylserine-mediated recognition.

Microglia, the tissue macrophages of the brain, play a crucial role in recognition and phagocytic removal of apoptotic neurons. The microglial receptors for recognition of apoptotic neurons are not yet characterized. Here we established a co-culture model of primary microglia and cerebellar granule neurons to examine the receptor systems involved in recognition/uptake of apoptotic neurons. Treatment with 100 microM S-nitrosocysteine induced apoptosis of cerebellar neurons as indicated by nuclear condensation and phosphatidylserine exposure to the exoplasmic leaflet of the plasma membrane. Microglial cells were added to neurons 2 h after apoptosis induction and co-cultured for 6 h in the presence of ligands that inhibit recognition by binding to respective receptors. Binding/phagocytosis was determined after combined 4', 6-diamidino-2-phenylindole/propidium iodide (for apoptotic/necrotic neurons) and lectin staining (for microglia). Uptake of apoptotic neurons was reduced by N-acetylglucosamine or galactose, suggesting that recognition involves asialoglycoprotein-like lectins. Furthermore, the inhibition of microglial binding/uptake of apoptotic neurons by RGDS peptide suggests a role of microglial vitronectin receptor. As microglia selectively bind lipid vesicles enriched in phosphatidylserine and O-phospho-L-serine interfered with the uptake of apoptotic neurons, an involvement of phosphatidylserine receptor is rather likely. Apoptotic neurons do not release soluble signals that serve to attract or activate microglia. Collectively, these results suggest that apoptotic neurons generate a complex surface signal recognized by different receptor systems on microglia.

Animals↗
PubMed2000

Three cases with different presentation of fentanyl-induced muscle rigidity--a rare problem in intensive care of neonates.

We report about two newborns with sudden onset of inability of mechanical ventilation due to transient chest wall rigidity after fentanyl i.v. bolus of 2 and 4 microg/kg, respectively, resulting in severe hypoxemia and secondary bradycardia. A third case developed a rigidity of the tongue after fentanyl bolus, which created some unusual difficulties in bypassing the tongue for insertion an endotracheal tube. Because of common usage of this agent for analgesia we direct attention to the possibility of fentanyl-induced muscle rigidity. We underline the necessity of a slow bolus injection to prevent this dangerous adverse effect and we recommend the administration of naloxone and/or muscle relaxants as therapy in conjunction with mechanical ventilation.

Analgesics, Opioid↗
PubMed2000

Combination of high-dose chemotherapy and monoclonal antibody in breast-cancer patients: a pilot trial to monitor treatment effects on disseminated tumor cells.

BACKGROUND: Tumor relapse occurring in high-risk breast cancer patients after high-dose chemotherapy (HDC) and autologous stem-cell transplantation may arise from cells resistant to chemotherapy, as well as from tumor cells reinfused with autologous stem cell grafts. This pilot study was designed to investigate whether ex vivo immunomagnetic purging of PBSC and subsequent immunotherapy with MAb 17-1A is feasible and can reduce the number of disseminated tumor cells in BM. METHODS: Twelve high-risk breast-cancer patients, seven in Stage II/III and five in Stage IV (UICC breast cancer classification) underwent surgery of the primary tumor and received two cycles of induction chemotherapy, followed by HDC. After each cycle of induction chemotherapy PBSC were collected and incubated with Ab-coated immunomagnetic beads, to remove contaminating tumor cells. Prepared stem-cell grafts were transplanted 24 h after completion of HDC. After recovering from HDC all 12 patients received a total dose of 900 mg MAb 17-1A within 4 months. The effect of in vivo purging with MAb 17-1A after HDC was controlled by examining bone aspirates of the patients with an immunocytochemical assay, allowing the detection of one cytokeratin-positive tumor cell in 10(6) total nucleated cells (TNC). RESULTS: Tumor cells were found in 5/12 BM aspirates prior to chemotherapy and even after HDC. Further monitoring of BM aspirates for cancer cells during Ab therapy showed a consistent reduction of tumor cells in four out of these five patients. After a median clinical follow-up of 41 (32-48) months all four patients are alive. These results are different from those of a historical control group of six patients with breast cancer treated with the same chemotherapy schedule, but without 17/1A consolidation. In comparison with the patients from the study group, all patients of this control group revealed a significantly increased number of tumor cells in BM (p < 0.01) after HDC during follow-up of 5 (3-7) months. These preliminary results indicate that induction chemotherapy, followed by HDC, may reduce disseminated tumor cells in BM. DISCUSSION: Immunotherapy with MAb 17-1A after HDC may further eliminate residual disease without severe toxicity.

Adult↗
PubMed2000

Tetrameric indium trichloride, a new modification of a widely used compound.

The title compound, hexa-mu-chloro-1:2kappa(4)Cl;2:3kappa(4)Cl;3:4kappa(4) Cl-hexachlor o-1kappa(2)Cl,2kappaCl,3kappaCl, 4kappa(2)Cl-hexakis(diethylamine)-1kappa(2)N,2kappa N,3kappaN, 4kappa(2)N-tetraindium(III), [(InCl(3))(4)(Et(2)NH)(6)] or [In(4)Cl(12)(C(4)H(11)N)(6)], lies about an inversion centre and consists of four octahedrally coordinated In centres linked by bridging Cl atoms to form three four-membered In(2)Cl(2) rings.

Journal Article↗
PubMed2000

PCR detection and evidence of shedding of porcine circovirus type 2 in boar semen.

An experimental study was conducted to evaluate the potential presence of porcine circovirus type 2 (PCV2) in the semen of infected boars. Four mature boars were inoculated intranasally with PCV2 isolate LHVA-V53 propagated on PK15 cells. Two boars inoculated with the supernatant of noninfected PK15 cells were kept as controls. Serum samples were collected from all boars at 4, 7, 11, 13, 18, 21, 25, 28, 35, and 55 days postinoculation (dpi) and from the four PCV2-infected boars at 90 dpi. Samples were tested for the presence of antibodies to PCV2 by an indirect immunofluorescence assay and for the presence of PCV2 DNA by PCR and nested PCR. Semen samples were collected from all six boars at 5, 8, 11, 13, 18, 21, 25, 28, 33, and 47 dpi and tested for the presence of PCV2 DNA by a nested PCR assay. Antibodies to PCV2 could be detected as early as 11 dpi in one boar, and all four infected boars were found positive for PCV2 antibodies by 18 dpi. Thereafter all infected boars remained positive for antibodies to PCV2 until 90 dpi. Analysis of serum samples by nested PCR demonstrated the presence of PCV2 DNA as early as 4 dpi in three of four infected boars. Serum samples from all infected boars were positive for PCV2 DNA from 11 dpi until 35 dpi but were negative at 90 dpi. PCV2 DNA was detected as soon as 5 dpi in the semen of two infected boars and intermittently thereafter in the semen of all four infected boars. The semen of two infected boars was positive for PCV2 DNA at 47 dpi. Following infection, PCV2 DNA can be detected in semen concurrently with the presence of PCV2 DNA and antibodies in the serum. The present study suggests that PCV2 may be shed intermittently in the semen of infected boars.

Animals↗
PubMed2000

Head group-independent interaction of phospholipids with bile salts. A fluorescence and EPR study.

Bile salts are essential for phospholipid secretion into the bile. To study the relevance of the structure of phospholipids for their interaction with bile salts, we used spin-labeled or fluorescent phospholipid analogues of different head groups and acyl chain length. Those analogues form micelles in aqueous suspension. Their solubilization by bile salts resulting in the formation of mixed micelles was followed by the decrease of spin-spin interaction of spin-labeled analogues or by the relief of fluorescence self-quenching of (7-nitro-2-1,3-benzooxadiazol (NBD))-labeled analogues. Solubilization of analogue micelles occurred at and above the critical micellar concentration (CMC) of the bile salts. As revealed by stopped-flow technique, solubilization of NBD-analogues was very rapid with half times as low as 0.1 sec above the CMC of taurocholate. Both kinetics and extent of solubilization were independent of the phospholipid head group, but were significantly affected by the fatty acid chain length. Furthermore, using vesicles with varying phospholipid composition and different types of analogues in self-quenching concentrations, we could show that bile salt-mediated vesicle solubilization depended on the fatty acid chain length of phospholipids. In contrast, neither for phospholipids nor for analogues could an influence of the lipid head group on the solubilization process be observed. These findings support a head group-independent mechanism of bile salt-mediated enrichment of specific phospholipids in the bile fluid.

Bile Acids and Salts↗
PubMed2000

Retrospective serological survey of antibodies to porcine circovirus type 1 and type 2.

A retrospective serological survey was performed to determine the presence of antibodies to porcine circovirus type 1 (PCV1) and porcine circovirus type 2 (PCV2) in serum samples collected from sows at slaughterhouses in Canada in 1985, 1989, and 1997. Each serum sample was tested by indirect immunofluorescence on PCV-free PK15 cells, on PCV1-infected PK15 cells and on PCV2-infected PK15 cells. For the 3 years studied, sera positive to PCV1 and PCV2 were identified and the number of sera positive for PCV2 was greater than the number of sera positive for PCV1. The results indicated 1) that PCV2 appears to be the main PCV type circulating in the Canadian pig population, 2) that PCV2 had been circulating in the Canadian pig population at least 10 years before the postweaning multisystemic wasting syndrome (PMWS) was reported, and 3) that serological evaluation using PCV1 underestimates the seroprevalence of PCV2.

Animals↗
PubMed2000

[Does reduction in multifetal pregnancy increase the risk of poor outcome in twin pregnancy?].

OBJECTIVE: To compare perinatal results for multi-foetal pregnancies where the reduction was performed with pregnancies where the reduction was not performed. SETTING: Sanatorium Pronatal, Na Dlouhé mezi 4/12, 147 00, Praha 4--Hodkovicky. METHODS: We have analyzed results of pregnancies, after delivery, for women with twin pregnancy which originated in our sanatorium, as a result of treatment with assisted reproduction methods, in the period of time from January 1st 1996 to December 31st 1998. In the group being monitored there were 122 twin pregnancies originated as a result of reduction of triple and more-foetal pregnancies. We evaluated the percentage of miscarriages, length of pregnancies, weight of the newborns and the manner of termination of the delivery. These results were compared with our control group consisting of 180 cases of twin pregnancies which were not a result of reduction. RESULTS: Analysis was performed for those mothers only where complete data were available. At a 5% level of statistical significance, it was not proved that both groups differed in average term of pregnancy or average weight of the twins. Average age of the mothers differed at 5% level of significance (average age values were 30.16 for the group with reduction and 31.73 for the group without reduction). Fisher test on 5% significance level did not ascertain any significant difference in the probability of miscarriage between the group with reduction (5.26%) and the group without reduction (12.84%). At 5% level of statistical significance, no significant difference in probability of perinatal death of the foetus or delivery of a stillborn foetus was ascertained. However, it is necessary to point out a low frequency of these phenomena in our group. The percentage of cesarean sections did not differ significantly in both groups (86.24% in the group monitored vs 87.24% in the group of twins without reduction). CONCLUSION: The analysis of both groups proves that reduction of multi-foetal pregnancies does not worsen perinatal results in comparison to pregnancies where reduction was not performed.

Adult↗
PubMed1999

The homeobox gene Otx of the jellyfish Podocoryne carnea: role of a head gene in striated muscle and evolution.

In many bilaterian animals members of the Otx gene family are expressed in head or brain structures. Cnidarians, however, have no clearly homologous head and no distinct brain; but an Otx homolog from the jellyfish Podocoryne carnea is highly conserved in sequence and domain structure. Sequence similarities extend well beyond the homeodomain and Podocoryne Otx can be aligned over its entire length to human OTX1, OTX2, and CRX. The overall structure of Otx is better conserved from Podocoryne to deuterostomes while protostomes appear to be more derived. In contrast, functions seem to be conserved from protostomes to vertebrates but not in Podocoryne or echinoderms. Podocoryne Otx is expressed only during medusa bud formation and becomes restricted to the striated muscle of medusae. Cnidaria are the most basal animals with striated muscle. Podocoryne polyps have no striated muscle and no Otx expression; both appear only during the asexual medusa budding process. The common ancestor of all animals that gave rise to cnidarians, protostomes, and deuterostomes already had an Otx gene more similar to today's Podocoryne and human homologs than to Drosophila otd, while the head-specific function appears to have evolved only later.

Amino Acid Sequence↗
PubMed1999

Organotitanium Fluorides as Matrices for Trapping Molecular ZnF(2) and MeZnF.

Trapped as molecular solids, the transition metal fluorides ZnF(2) and MeZnF-the latter isolated for the first time-exist as adducts in [(Cp*TiF(3))(8)(ZnF(2))(3)] (1) and [(Cp*TiF(3))(4)(MeZnF)(2)] (2), respectively. Compounds 1 and 2 were obtained in reactions of [Cp*TiF(3)] (Cp*=C(5)Me(5)) with ZnMe(2) and Me(3)SnF in various molar ratios. The single-crystal structure of 1 is shown here; the unlabeled circles are F atoms.

Journal Article↗
PubMed1999

Reversible inactivation of cell-type-specific regulatory and structural genes in migrating isolated striated muscle cells of jellyfish.

We have investigated, by RT-PCR and in situ hybridization, expression of genes encoding regulatory and structural proteins in migrating mononucleated striated muscle cells of the medusa Podocoryne carnea. Expression of the three homeobox genes Otx, Cnox1-Pc, and Cnox3-Pc; a specific splice variant of the myosin heavy chain gene (Myo1); and a tropomyosin (Tpm2) is stable in isolated and cultured striated muscle tissue. When grafted onto cell-free extracellular matrix (ECM), muscle cells of the tissue fragments leave their native ECM and migrate as a coherent tissue onto a host ECM until a stretched cell monolayer is formed. Shortly after the first cells of the grafted isolate have made contact with the host ECM, Otx and Cnox1-Pc expression is completely turned off in all cells of the graft, including those still adhering to their native ECM. Myo1 message disappears with a delay while the expression level of Tpm2 is strongly reduced. However, expression of the homeobox gene Cnox3-Pc, a msh-like gene, and of the ubiquitously expressed elongation factor 1 alpha is not affected by the migration process. All genes are reexpressed after 12-24 h, once migration of the cells has ceased. Our results demonstrate that the first few migrating cells induce a change in gene expression which is rapidly communicated throughout the entire tissue. Furthermore, we showed that commitment of striated muscle cells remains stable despite the transient inactivation of cell-type-specific regulatory and structural genes.

Animals↗
PubMed1999

Immortalized pancreatic duct cells in vitro and in vivo.

Although pancreatic adenocarcinoma has become one of the best characterized malignant diseases, severe diagnostic and therapeutic problems are still associated with this disease. The establishment of a molecular model of pancreatic carcinogenesis may provide tools that could result in earlier diagnosis of this disease and, in turn, improves prognosis. Since pancreatic adenocarcinoma seems to originate in epithelial cells in the pancreatic ducts, cultivation of native pancreatic duct epithelial cells (PDEC) is the initial step in the establishment of an in vitro model of pancreatic carcinogenesis. As these native cells survive only a short period in culture, the aim of this study was to establish a stable pancreatic duct cell line by immortalization with the SV40 large T antigen. Furthermore, initial steps in pancreatic carcinogenesis should possibly be imitated by additional transfections of mutated ki-ras and/or mutated p53 genes. By optimization of the isolation protocol and the culture medium, yield as well as proliferative activity of isolated PDEC was increased considerably. Transfection of SV40 large T antigen resulted in an increase in the proliferative lifetime of the isolated cells, but no real immortal phenotype was obtained. Moreover, one step in the transformation from the normal to the malignant phenotype was imitated successfully by additional transfection of mutated ki-ras.

Animals↗
PubMed1999

Injection of encapsulated cells producing an ifosfamide-activating cytochrome P450 for targeted chemotherapy to pancreatic tumors.

The prognosis of pancreatic cancer is poor, and current medical treatment is mostly ineffective. The aim of this study was to design a new treatment modality in an animal model system. We describe here a novel treatment strategy employing a mouse model system for pancreatic carcinoma. Embryonal kidney epithelial cells were genetically modified to express the cytochrome P450 subenzyme 2B1 under the control of a cytomegalovirus (CMV) immediate early promoter. This CYP2B1 gene converts ifosfamide to its active cytotoxic compounds, phosphoramide mustard, which alkylates DNA, and acrolein, which alkylates proteins. The cells were then encapsulated in a cellulose sulphate formulation and implanted into preestablished tumors derived from a human pancreatic tumor cell line. Intraperitoneal administration of low-dose ifosfamide to tumor bearing mice that received the encapsulated cells results in partial or even complete tumor ablation. Such an in situ chemotherapy strategy utilizing genetically modified cells in an immunoprotected environment may prove useful for solid tumor therapy in man.

Animals↗