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Biomedical subjects

H Mann

Publications and source records attributed to H Mann.

At least 91 records · Page 5Linked to original sources
PubMed1987

Effects of improved contrast on lung-nodule detection. A clinical ROC study.

We evaluated the effects of unsharp masking and highly efficient scatter rejection on film-screen chest radiographs of cancer patients. Unsharp masking significantly improved the detectability of lung nodules and visibility of anatomic structures in poorly penetrated areas of the chest. Highly efficient scatter rejection by an improved antiscatter grid provided only modest additional benefits. The study supports the conclusion that nodule detection in poorly penetrated areas on conventional chest radiographs is limited primarily by display contrast, whereas in the well-penetrated lung fields it is limited primarily by confusing background structures, rather than inadequate contrast. A method for analyzing clinical nodule detection data by transforming the FROC data to ROC coordinates also is demonstrated.

Humans↗
PubMed1987

Radiographic differentiation between different etiologies of pulmonary edema.

We compared the plain chest radiographs of critically ill patients who had different types of pulmonary edema and evaluated the radiographs according to a standardized score sheet of findings. We included 94 total cases of pulmonary edema: 49 with cardiogenic, 33 with permeability, and 12 with renal/overhydration pulmonary edema. Patients with cardiogenic edema had enlarged hearts, vascular engorgement, septal lines, and absence of air bronchograms significantly more often than patients with permeability pulmonary edema. Renal/overhydration patients had enlarged hearts significantly more often than patients with permeability edema. There were no other statistically significant differences. Heart size and presence or absence of septal lines could have been used to distinguish cardiogenic and permeability edema in 83% of cases.

Capillary Permeability↗
PubMed1987

[Sialic acid containing compounds in the hemofiltrate of patients with chronic renal insufficiency. II. Isolation and structure determination of sialoglycopeptides].

Four sialyl glycopeptides have been isolated from the hemofiltrate of a patient with end stage renal disease using reverse osmosis, gel filtration and ion-exchange chromatography. Structural studies including one- and two-dimensional 1H-NMR spectroscopy, FAB mass spectrometry and enzymatic degradation indicated the following structures: (Formula: see text). While the disialyl glycopeptide has been previously characterized from normal and pregnancy urine, the three other sialyl glycopeptides could be isolated for the first time from biological material. The origin of these compounds and their possible clinical relevance is subject to further investigations.

Female↗
PubMed1987

[Isolation and NMR spectroscopic characterization of sialic acid compounds and hemofiltrate of chronic uremia patients].

Eight sialyloligosaccharides have been isolated from the hemofiltrate of a patient with end stage renal disease using reverse osmosis, gel filtration, ion-exchange and high-performance liquid chromatography. The structures were predominantly elucidated by one- and two-dimensional 1H- and 13C-NMR spectroscopy: 1 NeuAc alpha 2-3Gal beta 1-4Glc; 2 NeuAc alpha 2-6Gal beta 1-4Glc; 3 NeuAc alpha 2-3Gal beta 1-4GlcNAc; 4 NeuAc-alpha 2-6Gal beta 1-4GlcNAc; 5 NeuAc alpha 2-3Gal beta 1-4-GlcNAc alpha 1-P; 6 NeuAc alpha 2-6Gal beta 1-4GlcNAc alpha 1-P; 7 NeuAc alpha 2-3Gal beta 1-3GalNAc alpha 1-P; 8 NeuAc alpha 2-8NeuAc. While compounds 1-7 are also components of normal human urine, di-N-acetyl-D-neuraminic acid (8) could be isolated for the first time from biological material. The origin and possible clinical relevance of these compounds have to be proved in further investigations.

Blood↗
PubMed1986

[Acquired renal cysts in maintenance dialysis patients].

Ultrasonographic examination of the kidneys of 111 patients on long term maintenance hemodialysis was performed. None of the patients had genuine polycystic kidney disease. In many patients acquired cysts were found. Frequency and volume of these cysts were the same on the right and left side. There was no correlation between the age of the patients and the number of cysts. There were no differences concerning sex and type of primary renal disease. There was a significant positive correlation between time on maintenance hemodialysis and number of cysts but no correlation between number of cysts and hemoglobin concentration. This is in contrast to data in the literature. Clinical relevance of acquired kidney cysts in dialysis patients concerns hematuria, retroperitoneal bleeding, kidney stone formation, septicemia and malignancy.

Adult↗
PubMed1985

Ionometry versus flame photometry in dialysis therapy.

In order to decide whether the ionometer can be accepted as an alternative to the flame photometer in the measurement of sodium and potassium, extensive measurements with ionometry in parallel with flame photometry were performed in serum and dialysis fluid during dialysis. The influence of parameters which influence both ionometry and flame photometry in a different way (protein concentration, pH, acetate, and bicarbonate concentration) was investigated. The correlation between the two methods for potassium in serum and dialysis fluid was excellent (r greater than 0.95), but unsatisfactory for sodium in serum (r = 0.77) and in dialysis fluid (r less than 0.85). This low correlation is attributed in a greater extent to the random errors caused by flame photometry than by ionometry. Ionometry can be accepted as an alternative to flame photometry in dialysis therapy.

Evaluation Studies as Topic↗
PubMed1985

[Results of treatment of acute cholecystitis following conservative therapy, interval operation and early operation].

The results achieved by conservative treatment interval operation and early operation in 981 patients suffering from acute cholecystitis were compared in a retrospective study by means of electronic data processing (EDP). There is no difference in length of operating time, intra- and postoperative complications and mortality rate between operation at an interval and early operation. By introducing the early operation the total mortality rate of all patients suffering from acute cholecystitis decreased from 7% to an average of 2.5%.

Acute Disease↗
PubMed1984

Combination of conventional and high-performance liquid chromatographic techniques for the isolation of so-called "uraemic toxins".

Using fluids from the artificial kidney as an example, a generally useful combination of separation techniques is described for the preparative isolation of biologically active subfractions from extremely heterogeneous and diluted biological fluids. Haemofiltrate (20 l) and dialysate (100 l), respectively, are desalted and concentrated in one step by reverse osmosis using membranes with a nominal cut-off of 500 Daltons. The retentate with high concentrations of "uraemic toxins" is fractionated by preparative ion-exchange chromatography (double column technique with detection at 206 nm) and size exclusion chromatography yielding large amounts of ninhydrin-positive subfractions which inhibit DNA synthesis of rat bone marrow and HeLa cells in vitro, respectively. These fractions were analyzed by reversed-phase and size exclusion high-performance liquid chromatography. Many of the isolated fractions were shown to contain peptides.

Animals↗