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M Huber

Publications and source records attributed to M Huber.

315 records · Page 18Linked to original sources
PubMedDate not supplied

Presentation and experimental verification of a physico-mathematical model describing the migration across functional barrier layers into foodstuffs.

For several years there has been an ongoing controversial scientific discussion about the so-called functional barrier concept which, although mostly connected with the re-use of recycled plastics for food packaging, has general relevance and is principally applicable to any type of multilayer structure. Concerning the definition of the efficiency of a functional barrier there exists different understandings, ranging from the absolute physical barrier requirement over the acceptance of toxicologically insignificant migration to a completely lag time-related definition. The starting point of this work was the fact that functional barriers are in most cases already in-situ-contaminated due to the thermally extreme coextrusion conditions of the manufacturing process. As a consequence, middle layer contaminants may already have penetrated the functional barrier of a food package and may provide direct contact with the foodstuff at the time when the package is filled. Nevertheless, depending on the individual food package parameters, the remaining functional barrier efficiency can still prevent inadmissible migration. To meet this real-life situation and to describe the underlying migration process a theoretical migration model was developed and experimentally verified in this work using artificially-contaminated multilayer HIPS sheets with different functional barrier thicknesses. An important result of this study was the finding that compared with the interdiffusion between the package's layers in situ during their formation in the coextrusion process, the interdiffusion at ambient temperature until the filling time point of the package is able to be neglected.

Chlorobenzenes↗
PubMedDate not supplied

Imaging articular cartilage defects with 3D fat-suppressed echo planar imaging: comparison with conventional 3D fat-suppressed gradient echo sequence and correlation with histology.

PURPOSE: Our goal was to shorten examination time in articular cartilage imaging by use of a recently developed 3D multishot echo planar imaging (EPI) sequence with fat suppression (FS). We performed comparisons with 3D FS GE sequence using histology as the standard of reference. METHOD: Twenty patients with severe gonarthrosis who were scheduled for total knee replacement underwent MRI prior to surgery. Hyaline cartilage was imaged with a 3D FS EPI and a 3D FS GE sequence. Signal intensities of articular structures were measured, and contrast-to-noise (C/N) ratios were calculated. Each knee was subdivided into 10 cartilage surfaces. From a total of 188 (3D EPI sequence) and 198 (3D GE sequence) cartilage surfaces, 73 and 79 histologic specimens could be obtained and analyzed. MR grading of cartilage lesions on both sequences was based on a five grade classification scheme and compared with histologic grading. RESULTS: The 3D FS EPI sequence provided a high C/N ratio between cartilage and subchondral bone similar to that of the 3D FS GE sequence. The C/N ratio between cartilage and effusion was significantly lower on the 3D EPI sequence due to higher signal intensity of fluid. MR grading of cartilage abnormalities using 3D FS EPI and 3D GE sequence correlated well with histologic grading. 3D FS EPI sequence agreed within one grade in 69 of 73 (94.5%) histologically proven cartilage lesions and 3D FS GE sequence agreed within one grade in 76 of 79 (96.2%) lesions. The gradings were identical in 38 of 73 (52.1%) and in 46 of 79 (58.3%) cases, respectively. The difference between the sensitivities was statistically not significant. CONCLUSION: The 3D FS EPI sequence is comparable with the 3D FS GE sequence in the noninvasive evaluation of advanced cartilage abnormalities but reduces scan time by a factor of 4.

Aged↗
PubMedDate not supplied

Influence of cell culture conditions and passage number on the response of membrane voltage to ATP and angiotensin II in rat mesangial cells.

The influence of passage number and different culture conditions on the effect of ATP and angiotensin II (A II) on membrane voltage (Vm) of rat mesangial cells (MC) was examined with the patch clamp technique in slow and fast whole cell recordings. MC were characterized immunologically and grown in standard medium in primary culture (PC) and long-term culture up to passage 21 in the presence of 90 g/l fetal calf serum (LTC/+FCS) or without or with 5 g/l FCS for 1-3 days (LTC/-FCS). In all three series the studies were performed in a FCS-free Ringer-like solution. Vm of MC did not differ in the series (PC: -49 +/- 1 mV, n = 151; LTC/+FCS: -52 +/- 1 mV, n = 49; LTC/-FCS: -51 +/- 1 mV, n = 44). In primary culture and long-term cultured MC up to passage 8, FCS (ED50 approximately 5 g/l), ATP (ED50 approximately 2 x 10(-6) mol/l) and A II (ED50 approximately 5 x 10(-10) mol/l) induced a depolarization of Vm. Reduction of extracellular Cl- concentration (from 145 to 32 mmol/l) had no effect on Vm but led to an increased depolarization of Vm by FCS, ATP and A II. In long-term cultured MC above passage 8 grown with 90 g/l FCS both ATP and A II induced a concentration-dependent hyperpolarization of Vm, which was attenuated in increased extracellular K+ concentration (from 3.6 to 33.6 mmol/l). In long-term cultured MC beyond passage 8, grown without or with a reduced FCS concentration of 5 g/l, ATP and A II led to a transient depolarization of Vm, which was increased in the presence of 32 mmol/l extracellular Cl-. The depolarization was followed by a hyperpolarization, which was attenuated in the presence of increased extracellular K+. The data indicate that vasoactive agents depolarize Vm of MC in primary culture by activating a Cl- conductance, whereas they hyperpolarize Vm by activation of a K+ conductance in long-term cultured MC grown with FCS. The latter effect was partially reversed when FCS was omitted.

Adenosine Triphosphate↗
PubMedDate not supplied

Coronary angioplasty in stenotic lesions adjacent to coronary aneurysms.

The efficacy and safety of coronary angioplasty for stenoses adjacent to coronary aneurysms were studied in 25 patients (19 men and 6 women, mean age 62 +/- 11 years). The study represented 1.1% of patients undergoing coronary angioplasty during the study time period. The aneurysm diameter exceeded 1.8 +/- 0.2 times the normal artery diameter. Eleven (44%) of these aneurysms were localized in the left anterior descending, 3 (12%) in the circumflex and 11 (44%) in the right coronary artery. Percent diameter stenosis was reduced from 72 +/- 10% to 23 +/- 19%, and transstenotic gradient from 51 +/- 13 to 15 +/- 9 mmHg when measured. Clinical success (absence of pain on discharge without coronary bypass surgery, death, or infarction) was achieved in 24 (96%) patients. In one patient acute vessel closure occurred. No embolic events or coronary artery rupture occurred. Seventeen (71%) of the 24 successful patients remained asymptomatic at clinical follow-up (mean = 7.7 +/- 5.0 months). At late follow-up, one patient had sustained a myocardial infarction, two had elective bypass surgery, and two had successful repeat angioplasty. The data from this small patient population suggest that angioplasty for a stenosis adjacent to a coronary aneurysm can be performed safely with a high primary success rate.

Aged↗
PubMedDate not supplied

[Sampling plan for the establishment of a serologic Salmonella surveillance for slaughter pigs with meat juice ELISA].

The guidelines of the German Ministery of Food, Agriculture and Forestry outlining a Salmonella surveillance programme, "Leitlinien für ein Programm zur Reduzierung des Eintrags von Salmonellen durch Schlachtschweine in die Fleischgewinnung" (February 5th, 1998), provide a staggered spot-check size depending on the annual production of slaughtery pigs. A classification of farms into three quality categories (< 20%, 20-40%, and > 40%) is performed by salmonella antibody levels detected in meat samples using ELISA. Beside a fundamental inquiry into the salmonella status, the programme ought to lead to a decreased burden on slaughtery pigs and finally to a reduced salmonella entry into meat handling and processing companies. The spot-check plan is based on an unfavourable initial position and does not consider the real situation of salmonella load in pig fattening farms. For many farms the procedure will lead to an unjustified expenditure of examinations. In simple model calculations it is shown how a significant reduction of testing amount can be reached and statistical reliability is guaranteed, too. At the same time, we attempt to find a compromise between optimal spot check size and practicability. For reasons of free enterprise, an additional category would be desirable containing farms without any positive antibody titres in the samples. The results achieved so far indicate that a large number of German slaughter pig producers would fall into this category, without the necessity of a higher examination effort.

Abattoirs↗
PubMedDate not supplied

[Meat juice ELISA for determination of Salmonella incidence in slaughter pig herds in Bavaria].

Meat samples from diaphragm pillars were randomly taken from 3,048 pigs of 52 Bavarian herds after slaughtery. Meat-juice was collected and tested for salmonella antibodies in an indirect ELISA. The number of samples was calculated according to the annual production of slaughter pigs of a farm outlined in the "Leitlinien für ein Programm zur Reduzierung des Eintrags von Salmonellen durch Schlachtschweine in die Fleischgewinnung" from February 05th, 1998 (< 100 slaughter pigs: 45 samples, 100-200 slaughter pigs: 50 samples, > 200 slaughter pigs: 60 samples per year). Salmonella antibodies were detected in 48 carcasses (1.6%) of 12 farms (23.1%). However, 33 (68.8%) of these carcasses were originated from a single farm which had to be classified into category III (prevalence of > 40% in the samples). No bacteria could be isolated from this farm in a follow up examination. The 51 other farms (98%) were classified into category I (prevalence of < 20% in the samples). Farms with in/out-management showed a higher degree of reagents (2.1T%) than farms with continuous stabling (0.8T%). In a pig experimentally immunized with LPS-antigen preparations of Salmonella typhimurium it was shown that antibodies induced were nearly at the same level in all meat samples and even in selected organs (liver, kidney, parotis, mesenteric lymph nodes).

Animals↗
PubMedDate not supplied

Helicobacter pylori infection does not correlate with plasma ammonia concentration and hepatic encephalopathy in patients with cirrhosis.

BACKGROUND/AIMS: In patients with cirrhosis, infection of the stomach with Helicobacter pylori may increase ammonia production and, consequently, the incidence of hepatic encephalopathy. To test this hypothesis a retrospective analysis was performed in patients with a transjugular intrahepatic portosystemic shunt. These patients are regarded to be ideal candidates for such a study since they have a high bioavailability of gut-derived ammonia and many of them develop spontaneous hepatic encephalopathy. METHODOLOGY: In 132 patients (Child-Pugh class A: 24%, B: 49%, C: 27%) with stable transjugular intrahepatic portosystemic shunt function for more than 3 months (mean follow-up: 15.5 +/- 10.8 months) the diagnosis of H. pylori infection was established by a specific and sensitive immunoblot assay for IgG- and IgA-antibodies. During follow-up, hepatic encephalopathy was assessed by clinical examination and a structured questionnaire. Venous plasma ammonia concentration was measured at the time of antibody determination (end of study period). RESULTS: Eighty-four patients (64%) had negative and 48 patients (36%) had positive immunoblots for H. pylori. The groups were comparable with respect to age, gender, etiology of cirrhosis, Child-Pugh class, follow-up after transjugular intrahepatic portosystemic shunt, and shunt function. The ammonia concentrations of the patients without (group 1) and with antibodies against H. pylori (group 2) were 73 +/- 27 and 69 +/- 28 mumol/L (mean +/- SD), respectively. Hepatic encephalopathy occurred in 23 of 84 patients (27%) of group 1 and in 11 of 48 patients (23%) of group 2. CONCLUSIONS: A positive immunoblot for H. pylori antibodies neither correlates with plasma ammonia concentration nor with the incidence of hepatic encephalopathy in patients with cirrhosis of the liver and portosystemic shunt.

Adult↗
PubMedDate not supplied

Three novel point mutations in the keratinocyte transglutaminase (TGK) gene in lamellar ichthyosis: significance for mutant transcript level, TGK immunodetection and activity.

We have investigated 8 patients from 7 unrelated families with lamellar ichthyosis (LI) for defects in the keratinocyte transglutaminase (TGK) gene. We have characterized three novel homozygous mutations and a previously reported splice acceptor site mutation. One patient showed a C-to-T change in the binding site for the transcription factor Sp1 within the promoter region. Another patient had a Gly 143-to-Glu mutation in exon 3 and a third patient, affected with a particular form of LI sparing the four limbs, demonstrated a Val382-to-Met mutation within exon 7. These three patients exhibited drastically reduced transglutaminase activity and an absence of detectable TGK polypeptide, as assessed by immunofluorescence and immunoblotting. Northern blot analysis showed that the Sp1 site mutation was associated with profound reduction of TGK transcript levels whereas normal transcript levels were observed for the two missense mutations. We hypothesize that the Sp1 site mutation impairs transcription of the TGK gene, whereas the two missense mutations induce structural changes leading to protein instability. Linkage to TGK was excluded in another family and no evidence for TGK defect was found in 3 other patients. These results further support the involvement of TGK in some patients with LI. They identify a TGK mutation as a cause for non-generalized LI and further delineate the molecular mechanisms underlying TGK deficiency in LI.

Adult↗