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Biomedical subjects

U Hofmann

Publications and source records attributed to U Hofmann.

At least 73 records · Page 4Linked to original sources
PubMed1995

Immunoenzymometric assay of human glycogen phosphorylase isoenzyme BB in diagnosis of ischemic myocardial injury.

With a new immunoenzymometric assay we measured human glycogen phosphorylase isoenzyme BB (GPBB) in 116 healthy individuals, 14 patients with stable angina, 107 nontraumatic chest pain patients on admission to the emergency department [45 acute myocardial infarction (AMI), 49 unstable angina, 13 other diseases], and in serial samples from 41 AMI patients. GPBB was compared with creatine kinase (CK), CKMB mass, myoglobin, and cardiac troponin T. Receiver-operating characteristic plots demonstrated the significantly greater (P < or = 0.012) discriminatory power of GPBB to detect acute ischemic coronary syndromes compared with all other tested markers. GPBB was the most sensitive marker for detection of AMI during the first 4 h after onset of chest pain, and only GPBB was increased above the upper reference limit (7 micrograms/L) on admission in patients who had unstable angina at rest and reversible ST-T alterations. This and the high early sensitivity of GPBB are most likely explained by its function as a key enzyme of glycogenolysis.

Adult↗
PubMed1994

[Spinocellular cancer in lichen sclerosus et atrophicus of the vulva].

We report on a 78-year-old woman with a 47-year-history of lichen sclerosus et atrophicus of the vulva on which squamous cell carcinoma developed. The lesion started as a small nodule that increased gradually in size and became eroded. The tumour and the inguinal lymph nodes on both sides were excised. Physical examination, chest X-ray and sonography of the abdomen 15 months later showed no local recurrence or distant metastases. Lichen sclerosus et atrophicus of the vulva should be considered a possible precancerous condition.

Aged↗
PubMed1994

[Amelanotic polypoid malignant melanoma of the balloon cell type].

We describe a 59-year-old woman with amelanotic polypoid balloon cell melanoma. Physical examination showed exophytic erythematous tumour simulating a basal cell carcinoma or an adnexal tumour. Histopathology revealed a polypoid tumour that was composed mainly of balloon cells in sheets and nests. Examination 37 months after excision of the tumour with 3 cm safety margins disclosed no evidence of enlarged lymph nodes or cutaneous metastases. Metastases to internal organs could not be assessed because the patient repeatedly refused further examination for staging. To our knowledge our patient is the first case of amelanotic polypoid balloon cell melanoma to be reported in the German literature.

Antigens, Neoplasm↗
PubMed1994

Distribution and changing density of gamma-delta T cells in murine skin during the induced hair cycle.

Gamma-delta T cells (gdTC) are recognized as the predominant intraepidermal T-cell population in murine skin, although their physiological functions are still unclear. Little is known of the exact distribution of gdTC in the other epithelial skin compartments of normal mice. Using selective gdTC-receptor antibodies in immunohistology (alkaline phosphatase technique), the distribution and density of gdTC was analysed morphometrically in cryostat sections of full-thickness back skin of normal, adolescent C57 BL-6 mice in all the different stages of the depilation-induced hair cycle. We found that, during the entire hair cycle, V gamma 3-TCR-bearing lymphocytes are restricted to the epidermis, and to the epithelial hair bulb in, and distal to, the bulge area. No gdTC were seen in the sebaceous glands. During early anagen development, the number of pan-gdTC receptor-positive cells increased significantly (P < 0.005) in the interfollicular epidermis and the suprainfundibular portion of the hair bulb, whereas the number decreased in the infrainfundibular region (P < 0.005). As gdTC are thought to migrate into the skin only during embryogenesis, this finding suggests hair cycle-dependent, differential intraepithelial proliferation of gdTC in murine skin. We advocate employing only skin of defined hair cycle stages in immunological studies on murine skin, and discuss the value of the C57 BL-6 model for assessing the functions of gdTC in skin and hair biology.

Animals↗
PubMed1994

Expression of classical and non-classical MHC class I antigens in murine hair follicles.

Not all keratinocytes in human and rat hair follicles express MHC class I antigens (MHC I). In the present study, we report the first immunohistological profile of classical and non-classical MHC I expression in the skin of adolescent C57 BL-6 mice during the induced hair cycle. MHC I immunoreactivity (H-2b, H-2Db) is absent in the matrix and inner root sheath of growing (= anagen) hair follicles, and the dermal papillae are H-2b negative during catagen and telogen. This lack of normal MHC I expression may serve to sequester potentially damaging autoantigens from immune recognition. In addition, we present the first evidence of non-classical MHC class I antigen expression in normal mammalian skin: during the entire hair cycle, the distal hair follicle shows strong Qa-2 immunoreactivity, which appears to be restricted to an epithelial follicle compartment densely populated by gamma-delta T cells with which Qa-2 molecules may interact as part of a primitive antibacterial defense system of the follicle. The murine hair cycle is an attractive model for dissecting the functional roles of H-2b and Qa-2 molecules in hair biology and in related tissue-interaction systems.

Animals↗
PubMed1994

Alkaline phosphatase activity and localization during the murine hair cycle.

For unknown reasons, the pilosebaceous unit displays prominent alkaline phosphatase (AP) activity, and alterations in AP activity are seen in alopecia areata. The role of AP in hair biology and pathology has been obscured by contradictory reports on the localization and activity of AP during the hair cycle, and by a paucity of instructive models for studying AP functions. Using the C57 BL-6 mouse model for hair research, we have characterized endogenous AP with a simple histochemical developing solution routinely employed for AP immunohistology. This method was selective for AP, and revealed distinctive hair cycle-dependent changes in AP activity and localization. Although the dermal papilla displays unusually strong AP activity during the entire hair cycle, the outer root sheath is AP-positive only during late anagen and early catagen. Strong, rather homogeneous AP activity is seen in the sebaceous gland (SG) only during catagen and telogen. This AP staining pattern indicates hair cycle-dependent changes in SG functions, and differs to some extent from the previously reported AP activity during the hair cycle of various species. We propose a simple and effective technique for follicle classification based on the AP histochemistry of dermal papilla and sebaceous gland, and discuss uses of the C57 BL-6 mouse model for functional AP studies.

Alkaline Phosphatase↗
PubMed1994

[Value of magnetic resonance tomography in diagnosis of tethered cord syndrome in children].

The tethered cord syndrome is considered a trouble complex that is caused by fixation of the spinal cord by intra- or extradural components. Clinically it is characterized by motor and sensory dysfunction of the lower extremities, muscle atrophy, decreased or hyperactive reflexes, urinary and bowel incontinence, spastic gait, or orthopedic deformities. Traditionally, positive-contrast myelography has been the diagnostic procedure of choice, often supported by CT (post myelo-CT). With the improvement of surface-coil technology, MR imaging has become a useful diagnostic tool for the assessment of the spinal cord and canal without ionizing radiation. MR examinations of 80 patients with the clinical diagnosis of tethered spinal cord were reviewed retrospectively in order to define normal anatomy and pathological findings as well as to establish MR strategies in the diagnosis of tethered cord syndrome in children. In order to evaluate intraspinal lipomas, the width of the spinal canal and dysraphic lesions, T1-weighed sagittal and transverse images are useful. In case of deformities of the spinal column the corona slice orientation should be used. The filum terminale and its thickness is best seen in T2-weighed transverse and sagittal images. The extension of fat within the spinal canal over more then 6 vertebral bodies and more then 1.2 cm width could be an indication of a lipomatous malformation in the sacral spinal canal.

Adolescent↗
PubMed1993

Mass determination of 15-hydroxyprostaglandin dehydrogenase from human placenta and kinetic studies with (5Z, 8E, 10E, 12S)-12-hydroxy-5,8,10-heptadecatrienoic acid as substrate.

NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase catalyzes the first step in the metabolism of prostaglandins which is usually associated with physiological inactivation. A highly purified homogenous enzyme preparation from human placenta was used to determine the molecular mass and lack of quaternary structure of the enzyme. Furthermore we have examined enzyme kinetics of the purified enzyme with (5Z,8E,10E,12S)-12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) an equimolar coproduct of thromboxane biosynthesis. Using gel electrophoresis and gel filtration on FPLC, we could estimate a molecular mass of 28 +/- 1 kDa, indicating that the enzyme consists of one single protein chain. The exact molecular mass of the monomer was calculated by matrix-assisted laser desorption/ionization mass spectrometry to 28740 +/- 30 Da. (5Z,8E,10E)-12-oxo-5,8,10-heptadecatrienoic acid (oxo-HT) could be identified as the only product obtained from the enzymatic reaction with HHT. Quantification of this metabolite was achieved by gas chromatography/tandem mass spectrometry. The calculated enzyme kinetic constants for the formation of the metabolic product [Km (HHT) = 9.68 microM, Vi = 12.78 mU/micrograms] were in agreement with those determined for NADH formation (Km = 7.65 microM, Vi = 11.79 mU/micrograms). This demonstrates that HHT shows high affinity to the enzyme which is comparable to prostaglandin E2 (PGE2). As the product oxo-HT is a potent inhibitor of platelet aggregation, dehydrogenation of HHT might represent a biological activation step.

Chromatography, Gel↗
PubMed1992

Treatment of congenital tracheoesophageal fistula by endoscopic laser coagulation: preliminary report of three cases.

Three newborns with congenital tracheoesophageal fistula were treated by endoscopic laser coagulation. After radiologic and endoscopic diagnosis, laser coagulation of the mucosal layer of the fistula followed using Nd:YAG laser light transferred through an uncovered quartz fiber of 600 microns diameter. The successful and uneventful course in two cases contrasts with the incomplete obliteration in one case caused by inadequate energy application and/or early localized instillation of contrast medium for radiologic control examination. The advantages of this method include elimination of an operative procedure, exclusion of operative complications, and the possibility of repetition in recurrent cases. Care must be taken to prevent esophageal and tracheal damage by use of this method.

Bronchoscopy↗
PubMed1992

Ten statements on the motivation of medical teachers to teach.

Not only high number of students, increasing disintegration of curricula, lack of resources or hindering state regulations and laws seem to be the crucial problem in medical education worldwide but in particular substantially reduced interest and poor commitment in educational matters. Ten statements on possible reasons for the teachers' lack of motivation to teach are given and proposals for promoting their commitment are made.

Career Choice↗
PubMed1992

[Concentration of Fe, Fe-binding capacity, Cu and Zn in the plasma of piglets before and after oral administration of iron sulfate solution].

In piglets, the influence of the ingestion of Fe-enriched faeces, of the oral application of Fe-dextran (containing 150, 200 or 250 mg Fe) up to the 8th hour as well as the intramuscular injection of Fe-dextran (150 mg Fe) on the 2nd and 3rd day after birth on Fe-resorption was analysed. On the 5th to the 7th and on the 12th to the 14th day after birth the highest increase in the Fe-concentration and the highest values of the Fe-binding capacity of the plasma after the oral application of a solution of Fe-sulphate (containing 20 mg Fe/kg body weight) were confirmed in the piglets with the ingestion of Fe-enriched faeces and in the control piglets without Fe-supplementation. The increase of the iron concentration in the plasma induced a decrease in the concentration of Cu in some cases and of Zn in the plasma in most cases. The biggest increase in body weight was established in the piglets that ingested Fe-enriched faeces.

Administration, Oral↗
PubMed1992

[Grouped and combined blue nevi].

The simultaneous occurrence of blue and naevocytic naevus in the same lesion is rare and can be difficult to diagnose. Precise differentiation from nodular melanoma may only be possible by histopathological examination. Agminated blue naevi, first described by Upshaw et al. [25] in 1947, are also rare. It is important to differentiate these lesions from nodular melanoma with satellite metastases. We describe two patients with such unusual blue naevi.

Adult↗
PubMed1991

Magnetic resonance imaging as a new diagnostic criterion in paediatric airway obstruction.

Magnetic resonance imaging of the trachea was performed in 21 children with congenital or acquired narrowing of the trachea or main bronchi. Diagnosis included aortic arch anomalies, innominate artery compression, pulmonary artery compression and tracheomalacia. All patients were examined after bronchoscopy. The demonstration of the trachea and the surrounding tissue and vessels on MR images enables the cause of tracheal compression and the degree and location of collapse to be evaluated. MRI is a modality well suited to characterizing tracheal narrowing without employing ionizing radiation or intravenous contrast medium. All MRI examinations were carried out with the patient under general anaesthesia so as not to risk pulmonary deterioration during sedation. In the cases presented MRI is the diagnostic step of choice after tracheobronchoscopy and broadens the diagnostic potential in extrinsic tracheal or bronchial stenosis in paediatric patients.

Airway Obstruction↗
PubMed1991

MRI in tracheal stenosis by innominate artery in children.

Pediatric airway obstruction due to anomalies of the course of the innominate artery may produce respiratory distress. MR imaging of the trachea was performed after bronchoscopy on forty-one children with congenital tracheal stenosis. Bronchoscopy only allows the evaluation of the lumen of the trachea, and the degree and location of collapse, and it may be difficult to determine the etiology of the tracheal narrowing. In eighteen out of the forty-one patients MR imaging showed a compression of the trachea by the innominate artery. The MR imaging diagnoses were subsequently compared for accuracy with the diagnoses determined by direct surgical observations. MR imaging of the trachea, the surrounding tissue and vessels allows the evaluation of the cause of tracheal compression and the degree and location of collapse. For evaluation of the cause of airway obstruction. MRI is an ideal method depicting detailed anatomic structure without employing ionizing radiation or intravenous contrast medium.

Brachiocephalic Trunk↗