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Biomedical subjects

W Baumann

Publications and source records attributed to W Baumann.

At least 55 records · Page 3Linked to original sources

[Congenital intracranial teratoma with exophthalmos].

We report the rare case of a term newborn with an excessively large congenital, intracranial teratoma expanding into the right orbita and maxilla. The main symptoms were a total unilateral exophthalmos, a tumorous mass in the right cheek, macrocephaly with wide sutures, and a bulging fontanel. The diagnosis was confirmed by sonography, computed tomography and an exploratory excision from the retromaxillary region.

Brain↗

Histologic features in autoimmune hepatitis.

In order to see if the term of "plasma cell hepatitis", dating back to the early sixties, is still valid as a morphological diagnosis for autoimmune chronic hepatitis (AICH), and to find out if the existence of several subgroups is reflected by histopathology, we investigated 26 patients with chronic hepatitis, who met the criteria of autoimmune hepatitis based on tests for antinuclear, anti-smooth muscle antibodies (SMA) and on immunoassays for liver-kidney-microsomal (LKM) antigen, liver membrane antigen (LMA), and soluble liver antigen (SLA). In our material autoimmune hepatitis represent the entire spectrum of chronic hepatitis with variable inflammatory activity ranging from chronic persistent hepatitis to severe inflammatory lesions in chronic active hepatitis with transition to cirrhosis. When compared to viral chronic hepatitis A and non-A, non-B, however, characteristic features can be evaluated consisting in broad hypocellular areas of collapse and microacinar transformation of hepatocytes with hydropic swelling being the predominant type of cell lesion. Eosinophilic clumping and acidophilic necrosis were insignificant. Plasma cells were not a constituent feature of AICH. From this histopathologic pattern it may be concluded that the disease seems to run a sluggish course in most patients, however, in few cases a dramatic development may determine the disease with fatal acute episodes which are terminated by death or fade into slow progression. The different subgroups could not be distinguished by histopathology.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

[Cleavage and synthesis of sialic acids with aldolase. NMR studies of stereochemistry, kinetics, and mechanisms].

1H-NMR spectroscopy was used to study cleavage and synthesis of N-acetyl- and N-glycoloyl-D-neuraminic acid by Clostridium perfringens aldolase. Whereas the alpha-anomers of Neu5Ac and Neu5Gc serve as substrate in the cleavage reaction, alpha-ManNAc and alpha-ManNGc are its primary products. The same alpha-anomers are needed by the aldolase for the synthesis of Neu5Ac and Neu5Gc. During the enzyme reaction in D2O both H-atoms at C-3 of Neu5Ac are exchanged by deuterium, H-3e reacting faster than H-3a. Rate constants and concentrations at equilibrium of reactants are temperature- and pH-dependent: The amount of Neu5Ac in equilibrium increases with decreasing temperature and increasing pH-value. Based on these results a mechanism of aldolase action is discussed.

Clostridium perfringens↗

Isolation of unusually composed sialyl-compounds from hemofiltrate.

Sialyl compounds are essential components of various biological fluids but relatively little is known about their occurrence in the extracellular fluid of patients with end-stage renal disease. As we have developed a macropreparative method for concentrating and desalting a wide range of fractions from diluted biological fluids we have been able to isolate and identify 5 sialooligosaccharides, 3 sialosugarphosphates, 2 monosialoglycopeptides and 1 disialoglycopeptide. The structures have been elucidated predominantly by one and two-dimensional NMR spectroscopy, enzymatic degradation and FAB mass spectrometry. The accumulation of these compounds in uremic sera may be of particular interest as they may interact in the molecular biology of diseases typically associated with the uremic state, e.g., immune deficiency, neurological disorders, receptor binding abnormalities, complement system disturbances and cell membrane alterations.

Carbohydrate Conformation↗

[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↗

[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↗

[Testicular function in obstructive azoospermia].

The normal histological findings of the testicles with simultaneous azoospermia according to the former opinion renders greatly probable an obstruction of the seminal ducts. The reversed case of an ascertained obstruction, however, must not necessarily contain also normal histological structures or normal hormone tests. In the obstruction syndrome in 6 out of 23 cases we find changes in the diameter of the tubule, reductions of the spermatogenesis and changes at the interstice. Imprint-cytologically an increase of pathological spermatides at the cost of normal cell developments is shown. According to this the FSH-values are slightly but statistically significantly increased. LH, PRL and testosterone are found within the normal. For the diagnostic delimitation of the obstruction syndrome from a production azoospermia according to these findings the performance of a biopsy of the testicles with histological evaluation and the determination of the FSH-value. The relatively discrete tubular changes alone cannot be used for the explanation of the discrepancy between anatomical and functional results of the operative reconstruction of the seminal ducts.

Adult↗

[Treatment of congenital varicella with acyclovir].

We describe three newborns who developed varicella six hours, five or eight days after delivery. Because of the high lethality rate of congenital varicella treatment with acyclovir appeared to be indicated. Acyclovir was administered intravenously in a dosage of 3 X 5, 3 X 7.5, and 3 X 10 mg/kg/day for three to five days. All patients showed prompt clinical improvement and the skin lesions disappeared. Side effects were not observed. Dependent on the dosage radioimmunological determination of acyclovir serum levels revealed basic values between less than 0.34 to 13.9 mumol/l; peak levels ranged from 14.0 to 70.2 mumol/l. Our preliminary results demonstrate that acyclovir can be successfully used to treat congenital varicella. A dosage of at least 3 X 7.5 mg/kg/day is recommended.

Acyclovir↗

Real-time ultrasound in Crohn's disease: characteristic features and clinical implications.

Thirty-two children with Crohn's disease were evaluated by real-time ultrasonography. The typical pattern of Crohn's disease caused by bowel wall thickening is the "bull's eye phenomenon", the elongated tubular stiff bowel loop with narrowing of the lumen and the small bowel conglomerate tumor. In indefinable abdominal complaints sonography may lead to the correct diagnosis. The differential diagnosis of similar sonographic features and the limitations of ultrasound in gastrointestinal disease must be considered. In proven Crohn's disease the findings in follow-up match the clinical course and may delineate complications, such as ileus, abscess, hydronephrosis, gallstones or involvement of parenchymal organs, as seen in 15 patients. Thus ultrasound will restrict repeated x-ray studies and support patient management.

Adolescent↗

N-Acetylneuraminic acid storage disease.

Increased amounts of free sialic acid were found in body fluids, leukocytes, cultured fibroblasts, and liver tissue of a four-year-old boy with mental retardation, ataxia, and clinical and radiologic findings of a mild mucopolysaccharidosis. A diagnosis of Salla disease was made though in contrast to earlier reports, recurrent upper respiratory infections and hepatosplenomegaly were present already in infancy, and skeletal abnormalities of dysostosis multiplex were found in early childhood. Free sialic acid in the urine was identified as N-acetylneuraminic acid by 1H-NMR spectroscopy. Sialidase activities were normal. Increased amounts of bound sialic acid were found in liver and cultured fibroblasts and were attributed to an intracellular inhibition of sialyloligosaccharide-degrading neuraminidase by excessive amounts of free neuraminic acid. The molecular basis of N-acetylneuraminic acid storage disease is unknown but may be related to a defective transport mechanism preventing neuraminic acid from leaving the lysosomal compartment.

Cells, Cultured↗

Congenital renal arteriovenous malformation (aneurysmal type) in childhood.

We report on a 9-year-old boy with a congenital renal arteriovenous fistula of the aneurysmal type, a form previously not observed in childhood. The clinical picture was unusual with severe arterial hypertension, excessive polyuria and decreased levels of serum sodium and chloride as main signs. Clinical and biochemical findings normalised after nephrectomy of the kidney involved.

Arteriovenous Malformations↗

Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome (AIDS). Diagnosis with bronchial brushings, biopsy, and bronchoalveolar lavage.

Sixty-one diagnostic biopsies for Pneumocystis carinii pneumonia were performed on 40 homosexual male patients with acquired immunodeficiency syndrome (AIDS), using flexible fiberoptic bronchoscopy. Bronchial brushings and bronchoalveolar lavage were performed in conjunction with the biopsy in 58 and 29 bronchoscopies, respectively. Using a rapid methenamine silver stain, P carinii pneumonia was diagnosed in 27 (68 percent) of the patients. Twenty of these patients had a repeat biopsy one or more times for evaluation of therapy. Eighteen of the biopsies following two to three weeks of therapy were positive. There was an 84 percent correlation between findings on transbronchial brushing and biopsy (89 percent on initial biopsy before treatment) and an 86 percent correlation between bronchoalveolar lavage and biopsy. Additionally, transbronchial brushing permitted demonstration of Pneumocystis organisms in four follow-up bronchoscopies in which the biopsy was negative or inadequate. Rapid methenamine silver stain of transbronchial brushings permits diagnosis of P carinii pneumonia in patients with AIDS within one-half hour of bronchoscopy.

Acquired Immunodeficiency Syndrome↗

[H-NMR spectroscopy. Specificity of microbial sialidases against complex substrates].

The specificities of one viral and five bacterial sialidases were investigated by 1H-NMR-spectroscopy with substrates or substrate mixtures containing two sialic acid residues of different linkage types. This technique allows - in contrast to the methods used before - the simultaneous determination of the rates of hydrolysis of both NeuAc linkages in a single experiment. The substrate specificities of the enzymes are discussed on the basis of the relation of the rate constants k/k'. The data obtained are more exact and more informative than those of separate experiments as reported previously. Among the enzymes investigated, i.e. sialidases of fowl plague virus (FPV = VKH), Clostridium perfringens (CP), Vibrio cholerae (VC), Bifidobacterium bifidum var. pennsylvanicum (BBif), Bifidobacterium lactentis (BLac), and Arthrobacter ureafaciens (AU), the activity of the viral sialidase VKH shows the highest, the activities of the Bifidobacterium sialidases the lowest dependence on the nature and on the linkage type of the different substrates. All sialidases preferentially cleave the NeuAc alpha 2-3-Gal linkage with the exception of the enzyme of Arthrobacter ureafaciens (AU) which shows a higher affinity to alpha 2-6 linkages. However, this does not apply to the side-arm-linked NeuAc alpha 2-6 structure in NeuAc alpha 2-3 Gal beta 1-3 (NeuAc alpha 2-6)-GlcNAc beta 1-3Gal beta 1-4Glc (Substrate B). This substrate in generally cleaved very slowly and is hardly affected by the viral enzyme. After the alpha 2-3 linkage, the alpha 2-8 bond in NeuAc alpha 2-8 NeuAc alpha 2-3 Gal beta 1-4Glc(Substrate A) is most susceptible for the sialidases VKH, CP and VC. An elongation of the carbohydrate chain (Substrate D) is accompanied by a reduction of the rate of cleavage for all enzymes. The experiments with alpha 1-acid glycoprotein, fetuin, and with the glycopeptides obtained by proteolytic degradation of the latter, revealed the same specificity towards the alpha 2-3 and the alpha 2-6 linkages as the oligosaccharides. Influenced by the chemical nature and the size of the substrate, NeuAc is released from the native alpha 1-acid glycoprotein more quickly than from the corresponding glycopeptide. All sialidases investigated so far are strictly exo-enzymes as could be demonstrated by the cleavage of NeuAc alpha 2-8 NeuAc alpha 2-3 Gal beta 1-4Glc (Substrate A).

Arthrobacter↗