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Biomedical subjects

A Göbel

Publications and source records attributed to A Göbel.

10 recordsLinked to original sources
PubMed2004

Kinetic studies on the aggregation of Aspergillus niger conidia.

Morphology has a crucial effect on productivity and the supply of substrate for cultures of filamentous fungi. However, cultivation parameters leading to the desired morphology are often chosen empirically as the mechanisms governing the processes involved are usually unknown. For coagulating microorganisms like Aspergillus niger the morphological development is considered to start with the aggregation of conidia right after inoculation. To elucidate the mechanism of this process, kinetic studies were carried out using an in-line particle size analyzer. Based on the data obtained from these experiments a model for conidial aggregation is proposed in this article. It consists of two separate aggregation steps. The first one takes place immediately after inoculation, but only leads to a small decrease of total particle concentration. Most suspended conidia aggregate after a second aggregation step triggered by germination and hyphal growth. Aggregation velocity of this second phase is linearly dependent on the particle growth rate.

Algorithms↗
PubMed2001

IP(3)and cyclic ADP-ribose induced Ca(2+) release from intracellular stores of pancreatic acinar cells from rat in primary culture.

We have measured Ca(2+)concentration changes in intracellular Ca(2+)stores ([Ca(2+)](store)) of rat pancreatic acinar cells in primary culture in response to the Ca(2+)mobilizing substances inositol-1,4,5-trisphosphate (IP(3)) and cyclic ADP-ribose (cADPr) using the Ca(2+)-sensitive dye mag Fura-2. We found that in this cell model IP(3)releases Ca(2+)in a quantal manner. Higher Ca(2+)concentration in the stores allowed a response to lower IP(3)concentrations ([IP(3)]) indicating that the sensitivity of IP(3)receptors to IP(3)is regulated by the Ca(2+)concentration in the stores. Cyclic ADPr, that modifies 'Ca(2+)-induced-Ca(2+)-release' (CICR), was also able to release Ca(2+)from intracellular stores of pancreatic acinar cells in primary culture. In comparison to the Ca(2+)ionophore ionomycin, which induced a maximal decrease (100%) in [Ca(2+)](store), a hypermaximal [IP(3)] (10 microM) dropped [Ca(2+)](store)by 87% and cADPr had no further effect. Cyclic ADPr reduced [Ca(2+)](store)by only 56% and subsequent IP(3)addition caused further maximal decrease in [Ca(2+)](store). Furthermore, a maximal [IP(3)] caused the same decrease in [Ca(2+)](store)in all regions of the cell, whereas cADPr dropped the [Ca(2+)](store)between 20 and 80% in different cell regions. From these data we conclude that in primary cultured rat pancreatic acinar cells at least three types of Ca(2+)stores exist. One type possessing both cADPr receptors and IP(3)receptors, a second type possessing only IP(3)receptors, and a third type whose Ca(2+)can be released by ionomycin but neither by IP(3)nor by cADPr.

Adenosine Diphosphate Ribose↗
PubMed1997

Expression and characterization of a trpl homolog from rat.

Mammalian homologues of the Drosophila trp/trpl-gene-family code for "Ca(2+)-store-operated" channels. Here we describe the cloning and expression of a trp/trpl homologous gene from rat brain. The clone is named Rtrp3 because of its high homology to the recently described Htrp3 (Zhu et al (1996) Cell 85:661-671). Expression of Rtrp3 in the mammalian COS-1 cell line leads to 100% increase of capacitative Ca2+ entry as compared to the controls. This capacitative calcium entry can be completely blocked with La3+ (10 microM). We conclude that Rtrp3, a new member of the growing family of trp/trpl homologues in mammalians, is involved in "Ca(2+)-store-operated" Ca2+ entry into the cell.

Amino Acid Sequence↗
PubMed1991

[Sonographic findings in trauma-induced liver injuries].

In 12 of 49 patients operated on for liver injuries we performed sonographic examination of the abdomen on admission to hospital within the framework of emergency diagnostics. The most sensitive finding was the identification of the presence of intraabdominal free fluid. The liver injury itself was sonographically diagnosed in only 5 patients. Sonographically, an additional injury of the spleen was found in 2 of 3 patients; in one patient it was possible to detect an injury of the kidney.

Abdominal Injuries↗
PubMed1989

[Surgical treatment of liver metastases from colorectal carcinoma].

Between 1978 and 1985 a total of 49 patients (20 women and 29 men, aged 31-78 years) were operated upon for liver metastases of a colorectal carcinoma. Metastasis recurrences occurred in 42 of 46 patients (91%). Three patients died in connection with the operation (6.1%). The five-year survival rate was 10.7%. Neither number, site and volume of the metastases, level of carcinoembryonic antigen concentration, tumour differentiation, stage or site of primary tumour, nor type of operation (enucleation or hemihepatectomy) had any influence on survival rate. Since most of the recurrences in the liver had occurred after enucleation at the site of the previous resection, it is feasible that the results could be improved by extending the area of resection.

Adult↗
PubMed1985

[A method of computer-assisted evaluation of programmed single stimulation for determination of sinoatrial conduction time].

The determination of the sino-atrial conduction time by means of premature individual atrial stimulation is an important partial function in the intracardial sino-atrial functional test and a reasonable parameter in selected diagnostic questions for the clarification of syncopic conditions under suspicion of a sick-sinus syndrome. In order to alleviate the clinical use and to reduce the considerable expenditure of time in the calculation of the results for the determination of the sino-atrial conduction time by about 60% a computerized evaluation method was elaborated. This methodology resulted in an exoneration from the manual graphic-calculatory expenditure and in comparison to the traditional calculation method it did not show any statistically significant differences.

Computers↗
PubMedDate not supplied

Agonist-stimulated pathways of calcium signaling in pancreatic acinar cells.

In pancreatic acinar cells stimulation of different intracellular pathways leads to different patterns of Ca2+ signaling. Bombesin induces activation of both phosphatidylinositol 4,5-bisphosphate (PIP2)-specific phospholipase C (PLC) and phospholipase D (PLD). The latter leads to generation of diacylglycerol (DAG) in addition to that produced by activation of PIP2-PLC. Strong activation of protein kinase C (PKC) results in inhibition of Ca(2+)-induced Ca2+ release from Ca2+ pools arranged in sequence to the luminally located IP3-sensitive Ca2+ pools. Consequently the Ca2+ wave which starts in the luminal cell pole is slower in the presence of bombesin (5 microm/s) as compared to that in the presence of acetylcholine (17 microm/s) which activates PIP2-PLC but not PLD. Activation of high-affinity CCK-receptors triggers a Ca2+ wave with slow propagation (5 microm/s) due to stimulation of phospholipase A2 (PLA2) and generation of arachidonic acid, which in turn leads to inhibition of Ca(2+)-induced Ca2+ release. Low-affinity CCK-receptors are coupled to both PIP2-PLC and PLD.

Adenosine Diphosphate Ribose↗