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P Heitmann

Publications and source records attributed to P Heitmann.

At least 19 recordsLinked to original sources
PubMed2001

[Tuberculosis of the pancreas--a clinical rarity].

Pancreas tuberculosis is a rare diagnosis and is usually associated with miliary spread. Only a few cases are reported in the literature. A female patient was admitted with a history of uncharacteristic abdominal pain, weight loss, weakness, and intermittent fever. CA 19-9 was increased and the CT scan showed an irregular mass in the pancreatic tail. Suspecting the diagnosis of pancreatic cancer, a pancreas tail resection with splenectomy was performed. The histological examination showed pancreas tuberculosis. Mimicking pancreatic cancer or presenting with acute/chronic pancreatitis or obstructive jaundice, the diagnosis of pancreas tuberculosis is very difficult to make and is usually established after surgical treatment. Although pancreas tuberculosis is rare, it should be considered when evaluating a pancreatic mass.

CA-19-9 Antigen↗
PubMed1996

Comparative genotyping and phenotyping of glutathione S-transferase GSTT1.

Only limited information is available so far concerning the human glutathione S-transferase isoenzyme class theta encoded by the GSTT1 gene. The aim of the study was to characterize individuals in respect to a polymorphic deletion of the GSTT1 gene and to validate these results with the phenotypical determination of the "conjugator status" according to Hallier et al. (1993). Determination of the GSTT1 genotype was done in 40 healthy adults by using an assay based on internal standard controlled polymerase chain reaction. The GSTT1-1 phenotype was determined by measuring the erythrocyte conjugating activity towards methyl chloride using a gas chromatographic assay. Genotypically, 34 individuals out of 40 were classified as GSTT1 positive; the remainder were negative. These results could be confirmed by phenotyping in all but one case. In the present study the frequency of "nonconjugators" was 15%. Our study demonstrates the reliability of the suggested PCR assay for GSTT1 genotyping which is easier to perform than the phenotyping assay and is not affected by confounding factors.

Adult↗
PubMed1996

Enzymatic properties of transplanted glomerulosa cells.

There are several theories about the physiologic regeneration of adrenals and maintenance of physiologic steroid secretion after subtotal loss of adrenal cortical cells. According to the cell migration theory, adrenocytes from the zona glomerulosa migrate centripetally toward the medulla. This theory is opposed by the zonal theory according to which each zone resplenishes its cells independently. What these theories have in common is that they are based on data from the intact adrenal gland. We transplanted purified glomerulosa cells under the kidney's capsule of Lewis rats. The tissue was removed 30, 60, 90, and 150 days after transplantation to investigate the presence of two specific enzymes that are responsible for the secretion of aldosterone and corticosterone. Cytochrome p-450as is specific for glomerulosa cells producing aldosterone, and cytochrome p-45011beta is specific for fasciculata cells producing corticosterone. After sequencing the genetic code of these enzymes it became possible to demonstrate expression of the enzymes by in situ hybridization. The transplanted glomerulosa cells turned their enzymatic property to fasciculata cells expressing cytochrome p-45011beta. Our results suggest that glomerulosa cells are able to take over the physiologic function of a whole adrenal cortex in the absence of fasciculata cells, and that they are sufficient to maintain the function of the adrenal cortex.

Adrenal Medulla↗
PubMed1978

The interaction of uranyl ions with inorganic pyrophosphatase from baker's yeast.

The interaction of uranyl ions with inorganic pyrophosphatase from baker's yeast was investigated by measurement of their effect on the protein fluorescence. Fluorescence titrations of the native enzyme with uranyl nitrate show that there is a specific binding of uranyl ions to the enzyme. It was deduced that each subunit of the enzyme binds one uranyl ion. The binding constant was estimated to be in the order of 10(7) M-1. The enzyme which contains a small number of chemically modified carboxyl groups was not able to bind uranyl ions specifically. The modification of carboxyl groups was carried out by use of a water soluble carbodiimide and the nucleophilic reagent N-(2,4-dinitro-phenyl)-hexamethylenediamine. The substrate analogue calcium pyrophosphate displaced the uranyl ions from their binding sites at the enzyme. From the results it is concluded that carboxyl groups of the active site are the ligands for the binding of uranyl ions.

Calcium↗
PubMed1978

Fluorimetric characterization and influence of Cu2+ binding on the fluorescence of inorganic pyrophosphatase from baker's yeast.

The denaturation characteristics of inorganic pyrophosphatase from baker's yeast and the interaction with Cu2+ were investigated with fluorimetric methods. The position of the fluorescence emission spectrum with a maximum at 328 nm together with a quantum yield of 0.12 led to the conclusion that most of the tryptophan residues of the protein are buried in nonpolar inner regions of the molecule. The contribution of the tyrosine residues to the fluorescence of pyrophosphatase is only about 7%. Denaturation of the protein with denaturants or changes of the pH value cause a red shift of the fluorescence emission maximum. In the presence of Cu2+ ions a fluorescence quenching is observed. Thereby, a specific binding of one Cu2+ per subunit may be distinguished from further unspecific Cu2+ binding. The Cu2+ binding to the latter sites shows a time dependence according to a slow, reversible exposure of additional binding sites. This time dependent binding characteristics was also verified by following the free Cu2+ concentration with the fluorescent "metal indicator" epsilon-ADP.

Cations, Divalent↗
PubMed1977

[Manometry and gastro-esophageal closure mechanism. An attempt at evaluation (author's transl)].

The registration of resting pressures and motility activity has considerably increased our knowledge of the normal functioning of the esophagus. We have not jet solved all the methodological problems of manometry; however perfusion manometry, which is used today, has enabled us to make an exact cassification of functional disorders and adequate therapy. An understanding of the methodological problems involved is necessary for the correct use of the manometric method and the correct interpretation of its results. This precondition has not always been observed, especially in discussion of the gastro-esophageal closure mechanism, and has thu given rie to much confusion. An attempt at a critical evaluation should be the basis for future discussion.

Cardia↗