Search PubMed⌕ Search

Biomedical subjects

M Müller

Publications and source records attributed to M Müller.

At least 1,207 records · Page 67Linked to original sources
PubMed1988

Significance of disturbed lymph flow for the pathogenesis of pancreatitis. I. Ligature of the ductus thoracicus in the rat.

To examine the significance of a disturbed lymph drainage for the pathogenesis of acute necrotizing pancreatitis, thoracic duct ligation was performed in 53 Wistar rats. Histological examination of the pancreas and analysis of serum lipase and serum amylase were carried out at various time intervals from 1 h to 42 days after initiating the experiment. Sudden stop of the lymph flow induced a long lasting pancreatic edema, initially in the perilobular interstitium and eventually also within some lobules, with scattered necroses of whole acini or single acinar cells mainly in the peripheral zones of the lobuli. In addition, a marked interstitial inflammatory infiltrate developed, resembling lipophage granulomas. This was most likely due to alymphangeal reflux of sunflower oil, applicated for the visualization of the thoracic duct. These findings suggest that changes in the lymph flow may favour the development of acute necrotizing pancreatitis.

Amylases↗
PubMed1988

[Prenatal sonographic diagnosis of abdominal wall defects and stenoses of the intestinal tract].

Today prenatal sonographic diagnosis of abdominal defects and stenoses of the intestine is possible without few exceptions during general screening in the 20th week of gestation. In a retrospective study, 56 malformations in this area were investigated, which had been diagnosed at the University Hospital Freiburg during 1973 and 1985. Besides the criteria of sonographic diagnosis the etiology, incidence, prognostic factors, the course of pregnancy and delivery and the postpartal management are described. The rate of direct sonographic diagnosis in this area has increased from 26% up to 91%. The worst prognosis was found in infants with diaphragmatic hernias and exomphalos, whereas infants with stenosis of duodenum and small intestine had the best prognosis.

Abdominal Muscles↗
PubMed1988

[Surgical treatment of necrotizing enterocolitis--a retrospective study from 1975 to 1987].

Between 1975 and 1987 15 patients were operatively treated at the St. Gallen Children's Hospital for necrotising enterocolitis. The number of patients cured and those who died, as well as the time of outbreak of the illness, age and treatment are shown in tabular form. Early diagnosis and selective therapy decisively reduce lethality. Long-term results show normal psychomotor development and no intestinal disturbance.

Colostomy↗
PubMed1988

[The value of computed tomography in the search for an unknown primary tumor].

CT scans of 31 patients, who had been evaluated because of metastases of unknown origin, were reviewed. Diagnosis of the primary site was established in 18 of the 31 patients only. More than 18 patients had metastatic adenocarcinomas. CT scans were helpful in identifying an occult primary tumour in 6 patients; in 5 cases the primary location could not be detected by CT examination. In 2 patients CT scans considered a wrong organ to be the site of an unknown primary tumour.

Adenocarcinoma↗
PubMed1988

[Computed tomographic findings in 36 patients with space-occupying lesions of the thymus].

The CT examination of 36 patients with masses in the thymus (three thymus hyperplasias, 33 thymomas) were evaluated retrospectively. Three tumours in atypical positions posed problems in differential diagnosis from bronchial carcinomas and two cases with extensive pleural metastases had to be differentiated from pleural mesotheliomas. There were no certain morphological features on CT which indicated whether the mass was malignant. Eleven patients with thymomas had metastases; in seven of these they were extra-thoracic, with preference for supraclavicular lymph nodes, adrenals and the axial skeleton. Tumour progression and distant metastases were found particularly in malignant thymomas of the epithelial type. Calcification in a thymoma tends to indicate that it is malignant.

Adolescent↗
PubMed1988

[Behavior of visual acuity, visual fields and contrast sensitivity in simulated cataract].

Visual acuity, contrast sensitivity, and visual fields were examined with and without occluders both in a group of healthy subjects and in a group of patients with field defects (mostly caused by glaucoma). The various results were compared with one another as well as with the results obtained from a group of cataract patients examined before and after surgery. The results confirm clinical experience: visual acuity enables some conclusions to be drawn on the degree and progression of opacity of a lens. The changes in contrast sensitivity and in the visual field, however, represent rather the quality of the visual degradation. Contrast sensitivity and diffuse alterations in the visual field have similar progression patterns. The alterations in contrast sensitivity are more pronounced at higher frequency levels. The contrast sensitivity test can be recommended as a simple and complementary functional test, particularly on cataract patients with severe complaints and relatively good visual acuity. The results of occlusive experiments afford some practical conclusions which enhance knowledge and differentiation of visual field changes induced by cataract and glaucoma. These conclusions can provide a basis for further and more detailed investigations.

Adult↗
PubMed1988

Path integration in desert ants, Cataglyphis fortis.

Foraging desert ants, Cataglyphis fortis, continually keep track of their own posotions relative to home- i.e., integrate their tortuous outbound routes and return home along straight (inbound) routes. By experimentally manipulating the ants' outbound trajectories we show that the ants solve this path integration problem not by performing a true vector summation (as a human navigator does) but by employing a computationally simple approximation. This approximation is characterized by small, but systematic, navigational errors that helped us elucidate the ant's way of computing its mean home vector.

Journal Article↗
PubMed1988

Cytochrome c oxidase from Paracoccus denitrificans: both hemes are located in subunit I.

The two-subunit cytochrome c oxidase from Paracoccus denitrificans has been sequentially digested with chymotrypsin and Staphylococcus aureus V8 protease. The smaller subunit of the enzyme (apparent Mr 32,000) was split into numerous peptides that were removed by anion-exchange HPLC. The larger subunit was only digested to a limited extent (from an apparent Mr 45,000 to Mr 43,000), and the spectral properties were preserved relative to the native enzyme (a reduced minus oxidized difference spectrum with maxima at 447 and 607 nm in the Soret and alpha region, respectively). As judged from CO-reduced spectra this proteolytically digested, one-fragment oxidase was found to contain an equal amount of cytochromes a and a3. The enzymatic activity with reduced cytochrome c as substrate in the presence of Triton X-100 proceeded with equal affinity (apparent Km = 0.5-1.0 microM) and with a Vmax of approximately 20% (40 s-1) of that found with the native enzyme (200 s-1). When the assay system was supplemented with soybean phospholipids, the Km became 2 microM for both enzymes and the Vmax became 730 and 170 s-1 for the native and the digested enzyme, respectively. Thus subunit I of P. denitrificans oxidase, and most probably of the other cytochrome c oxidases as well, contains both hemes and at least one Cu atom and has significant enzymatic activity.

Chymotrypsin↗
PubMed1988

A 60-kDa cytoskeletal protein from Trypanosoma brucei brucei can interact with membranes and with microtubules.

The cytoskeleton of eukaryotic cells is a major determinant of cellular architecture and of many cellular functions. In addition to or in place of the transcellular cytoskeleton, many eukaryotic cells also contain membrane-associated cytoskeletal structures (membrane skeletons), which are important for cellular structure and function. The membrane skeleton of the parasitic hemoflagellate Trypanosoma brucei consists of a dense array of singlet microtubules (subpellicular microtubules), which are tightly associated to the overlying cell membrane. This study reports the identification of a microtubule-associated protein from Trypanosoma brucei that constitutes a component of the link between this microtubular array and the cell membrane. The protein can bind in vitro both to microtubules and to membrane vesicles or liposomes. Furthermore, it can crosslink microtubules and membrane vesicles, suggesting that it exerts a similar function in the membrane skeleton.

Animals↗
PubMed1988

Protective effects of a prophylactic treatment with the bisphosphonate 3-amino-1-hydroxypropane-1,1-bisphosphonic acid on the development of tumor osteopathies in the rat: experimental studies with the Walker carcinosarcoma 256.

The present report primarily describes protective effects of a long-term prophylactic treatment with 3-amino-1-hydroxypropane-1,1-bisphosphonic acid (APD) on the development of tumor-induced osteolytic bone destructions. Pretreatment with daily intravenous doses of APD 9.5 mg/kg for 1 week resulted in a significant reduction of Walker carcinosarcoma 256-induced bone destruction, when Walker cells were transplanted intraosseously (2 x 10(6) tumor cells/rat) 7 weeks later. Shorter pretreatment periods (4, 2 or 1 week prior to tumor inocculation) resulted in a nearly total inhibition of bone destruction as well as tumor-induced hypercalcemia. Tumor growth itself was not inhibited by APD pretreatment. Histological and microradiographical findings are reported. Consistent to our experiments and with regard to new immunocytological methods to detect single metastatic tumor cells in the bone marrow, potential risk groups may be defined which may profit from the prophylactic APD treatment to inhibit tumor-induced bone destructions.

Animals↗
PubMed1988

Renal V2 vasopressin receptor proteins: identification and enrichment.

The synthesis of the tritium labelled photoreactive analogue of 1-deamino-vasopressin [1-(3-mercaptopropionic acid, 8-(N6-4-azido-phenylamidino)-lysine] vasopressin is described. This analogue retains a high affinity for hepatic V1 and renal V2 vasopressin receptors (apparent dissociation constant KD approximately 1-2 nM). A membrane protein from bovine kidney and pig kidney with an apparent relative molecular mass (Mr) of 30,000 was preferentially labelled and with lower yield a protein band with a Mr-value of 50,000 to 60,000. The photolabelled 30,000-Mr protein from bovine kidney was enriched by size-exclusion chromatography and by reversed-phase-high-performance liquid chromatography.

Affinity Labels↗
PubMed1988

Pharmacological modulation of central monoaminergic systems and influence on the anticonvulsant effectiveness of standard antiepileptics in maximal electroshock seizure.

The influence of various substances modulating the activity of central noradrenergic, serotonergic or dopaminergic neurotransmission systems on the anticonvulsant effectiveness of phenobarbital (phenytoin, carbamazepine) was investigated in mice using the maximal electroshock seizure test (MES). The results demonstrated that especially the noradrenergic system might play a predominant role in modulating the efficiency of the standard antiepileptics tested. In general, pharmacological stimulation with different sympathomimetic drugs (e.g. methamphetamine, maprotiline, tranylcypromine, yohimbine) increased the anticonvulsant activity significantly. Conversely, pharmacological suppression of the noradrenergic system (e.g. 6-OHDA, phenoxybenzamine) reduced the activity of the antiepileptics. In contrast, some beta-receptor blockers with local anesthetic properties (e.g. propranolol, alprenolol, pindolol) were also able to enhance the protective effect of phenobarbital in higher concentrations. The influence of manipulations of serotonergic mechanisms was not so pronounced. However, substances such as 5-HTP, clomipramine, citalopram, zimelidine, showed also additive anticonvulsive effects. On the other hand, the dopaminergic system seemed to exert no significant influence in this respect. These findings give further support to the view that the noradrenergic system may play a remarkable role via the inhibitory function of noradrenaline in the CNS in suppression of epileptic activity and reveal also interesting aspects for a possible comedication in convulsive disorders.

Animals↗
PubMed1988

[Does sonographic kidney morphology and morphometry provide evidence of pediatric kidney function?].

Compared with conventional X-ray investigation, ultrasound examination has a variety of advantages in the evaluation of urinary tract disorders in infancy and childhood. It does not involve exposure to contrast medium and radiation; low costs, minimal stress to the young patients, high diagnostic accuracy and easy reproducibility are further benefits. Postoperative follow-up of obstructive disorders can be easily performed and the results quantified by means of ultrasound. Morphometric data correlate well with renal function. As urologists become more familiar with ultrasonic morphologic and morphometric data, X-ray examinations in childhood will be confined to a few specific indications.

Child↗