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Biomedical subjects

M Wagner

Publications and source records attributed to M Wagner.

At least 919 records · Page 51Linked to original sources
PubMed1988

Progressive and regressive changes in the nucleus pulposus. Part II. The adult.

The spines of 28 cadavers were studied with magnetic resonance (MR) imaging, correlated with anatomic sections, to characterize the progressive and regressive changes in the nucleus pulposus. Four additional types of nucleus pulposus were identified in this study. The transitional type (type II) of childhood had fibrous tissue that developed near the anulus fibrosus anteriorly or posteriorly. MR images showed a notch of reduced signal intensity in the nucleus pulposus where the fiber was developing. The adult type (type III), which is predominant after age 30 years, had an indistinct boundary between the nucleus pulposus and anulus fibrosus. MR images showed the fibrocartilage in the nucleus pulposus and inner anulus fibrosus as areas of high signal intensity. Adult disks with a tear of the anulus fibrosus (type IIIB) had a lower signal intensity on MR images and slightly reduced disk heights. This type may represent an early stage of degeneration. Degenerated intervertebral disks (type IV) had either dense disorganized fibrous tissue or fluid replacing the normal fibrocartilaginous structure of the nucleus pulposus. MR images showed narrow intervertebral disk spaces with either reduced signal intensity if collagen was present or increased signal intensity if fluid was present. This study suggests that the nucleus pulposus may progress normally through types I, II, and III.

Adult↗
PubMed1988

Anulus fibrosus in bulging intervertebral disks.

In this investigation the association of radial tears of the anulus fibrosus and bulging of the intervertebral disk was studied. An index of disk bulging was measured in sagittal anatomic sections in 149 lumbar disks from 31 cadavers. The indexes of disk bulging were correlated with stages of disk development and the presence of an annular tear. The largest disk-bulging indexes were always associated with radial tears of the anulus. Eighty-four percent of the disks with radial tears had disk-bulging indexes greater than 2.5 mm. Most normal adult disks had an index of less than 2.5 mm. The results challenge the concept that the anulus fibrosus is intact in bulging disks, although ruptured in herniated disks.

Adult↗
PubMed1988

Comparison of urapidil and atenolol in hypertension.

The antihypertensive efficacy of urapidil was compared with that of atenolol in a double-blind randomised parallel-group 10-week study. 44 patients with essential hypertension entered the study, and 43 with a supine DBP of 100 to 125 mm Hg after a 2-week placebo period were randomised either to urapidil (n = 22; 60 to 120 mg/day) or atenolol (n = 21; 50 to 100 mg/day) for 8 weeks. Blood pressure, heart rate, electrocardiogram (supine and standing) and side effects were recorded every week, and medical examinations and laboratory tests were done at the end of the placebo and active treatments. 36 patients completed the trial (17 on urapidil and 19 on atenolol). Patients' characteristics were similar in the two groups, and there were no differences between them in blood pressure and heart rate at the end of placebo period. Both drugs produced a significant fall in supine and standing blood pressure; urapidil decreased supine blood pressure from 164/109 to 150/96 (p less than 0.001), and atenolol decreased it from 167/111 to 146/94 mm Hg by week 8 (p less than 0.001). There were no differences in the blood pressure-reducing effects of the two drugs. There was no change in heart rate in the urapidil group, but a marked reduction occurred in the atenolol group, with significant differences from placebo and urapidil (p less than 0.001). Side effects were reported in 32% of the urapidil group and in 29% of the atenolol group; however, these were mild and transient in all but two patients (urapidil = 1, atenolol = 1) who were withdrawn.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

[Occipitocervical fusion in metastasis to the dens].

Metastasis of the cervical spine or pathological fracture respectively presents a demanding therapeutical task. Pain and threatening, neurological deficit require an active action, even if curative treatment is unlikely. The remaining survival time after appearance of osseous metastasis is on the average nine to twelve months and justifies an operation, especially in view of psychosocial consequences for the patient. We are describing the unique case of cervical spinal manifestation after liver transplantation because of primary hepatic cancer.

Axis, Cervical Vertebra↗
PubMed1988

Effectiveness and safety of captopril (Tensiomin) in patients with hypertension.

Twenty patients with moderate (4) to severe (16) hypertension, whose blood pressure (BP) could not be controlled on the previous combined antihypertensive therapy, were investigated. In acute studies the first doses of captopril, 25 and 50 mg led to a significant drop in BP 30 min after administration. The maximum fall in BP was recorded at 90-120 min and this effect was maintained throughout the whole observation period (8 hours). The fall in BP was similar in supine and standing positions and there was no change in the heart rate. During long-term (14.5 months) therapy only 2 out of the 20 patients exhibited continuing good BP control with captopril monotherapy of a maximum daily dose of 150 mg. A comparison of the acute and chronic BP lowering effects of captopril showed that the first dose of captopril caused a significantly greater decrease in BP than chronic monotherapy. However, combined captopril with a diuretic or with a diuretic and calcium antagonist or beta blocker provided a sustained BP control, significantly better than the previously used anti-hypertensive combinations (182 +/- 27/115 +/- 11 mmHg vs 164 +/- 20/104 +/- 11 mmHg p less than 0.05). The Hungarian captopril preparation (Tensiomin), similarly to other captopril products, through its angiotensin converting enzyme inhibition, caused an increase in plasma renin activity and in concentration of plasma angiotensin I and a decrease in plasma angiotensin II. Eight out of the 20 patients developed side effects, which disappeared spontaneously in 4 patients within 2-14 days. Captopril was withdrawn in 3 patients for not achieving satisfactory BP control and/or because of side effects. It is concluded that captopril is safe and effective in the long-term treatment of hypertension, however, majority of the patients with severe forms of hypertension required double or multiple combinations.

Adrenergic beta-Antagonists↗
PubMed1988

MR and cryomicrotomy of C1 and C2 roots.

Paramedian sagittal MR images and cryotome sections in four cadavers were correlated with eight clinical MR studies to analyze the appearance of the C1 and C2 nerve roots and adjacent tissue. The C2 nerve roots and anatomically related venous plexus were identified. The C1 root, although not visualized by MR, could be localized by its relation to the vertebral artery, C1 lateral mass, and posterior arch.

Adult↗
PubMed1988

Pancreatic polypeptide (PP) response to food in type I diabetics with and without diabetic autonomic neuropathy.

Nineteen type I diabetics and 15 healthy subjects were given 500 ml of a mixed liquid test meal (flüssige Diabetikerkost, Fresenius, FRG) orally. Furthermore, heart rate variation during deep breathing and Valsalva maneuver was performed in order to test vagus nerve function. PP serum levels were determined before, and 2 to 160 minutes after finishing, the meal. In healthy subjects and in 10 diabetics without any sign of autonomic neuropathy of the vagus nerve a significant rise in PP serum values after the meal could be detected. In 7 type I diabetics with autonomic cardiac neuropathy (abnormal beat-to-beat variation during deep breathing and during the Valsalva maneuver) post-prandial PP levels remained low. Two diabetics without autonomic neuropathy were excluded from the test because endogenic PP antibodies were found in their serum. PP secretion after ingestion of a mixed protein-rich meal is mostly mediated by the vagus nerve or by the extravagal cholinergic system. After vagotomy, no PP secretion after a mixed meal could be detected. Measuring PP serum levels in diabetics after a mixed meal can be useful to check vagus nerve function in the gastrointestinal tract in order to detect autonomic neuropathy.

Adolescent↗
PubMed1987

Investigations on the binding of erythrogenic toxin A of Streptococcus pyogenes on human peripheral blood lymphocytes. I. Light and electron microscopical demonstration of cell surface receptors using colloidal gold-labelled toxin.

Receptors for erythrogenic toxin A (ETA) of Streptococcus pyogenes (strain NY-5) were demonstrated on human peripheral blood lymphocytes by binding of ETA-gold conjugates to the cell surface. The specificity of the binding was proved in control experiments. The dark-red granules observed by light microscopy on unfixed cells were revealed by transmission electron microscopy to be patches of gold particles. By light microscopy on samples from 48 blood donors a mean value of 34 +/- 13% of ETA-receptor bearing lymphocytes was ascertained. The predominant part of the cells exhibited only a weak or moderate labelling. Transmission electron microscopy of prefixed cells revealed an attachment of single gold particles distributed over the whole cell surface. Counts of gold particles on serial sections yielded depending on prefixation values of 50-600 receptors/cell (1% glutaraldehyde) and 1000-7000 receptors/cell (0.26% glutaraldehyde), respectively. ETA cloned in Streptococcus sanguis as well as the toxoid of ETA exhibited a comparable binding as ETA (NY-5).

Bacterial Proteins↗
PubMed1987

Density profile of group B streptococci, type III, and its possible relation to enhanced virulence.

The buoyant densities of virulent and colonizing group B streptococci, type III, were determined by centrifugation of bacteria on a linear, hypotonic density gradient. A total of 28 strains were investigated. Eleven strains were obtained from blood cultures of babies with early-onset disease, and eight strains were isolated from the cerebrospinal fluid of babies with late-onset septicemia and meningitis. Nine colonizing strains were genital isolates from pregnant women subsequently giving birth to healthy children. In each strain the buoyant density was determined before and after neuraminidase treatment. All strains showed an increase in the buoyant density after enzymatic removal of sialic acid, and the density differences before and after desialylation were calculated. The mean values of these differences for blood, cerebrospinal fluid, and colonizing isolates were 23.4, 25.3, and 10.6 mg/ml, respectively. The mean value for the colonizing strains differed significantly from the mean value for each group of virulent strains. All colonizing strains banded singly in the gradient, whereas five of the virulent strains divided into two density populations. Extracts of the low-density cells produced markedly more dense immunoprecipitates with type antiserum than did extracts of the high-density bacteria. One double-banding strain was positive for R protein. After separation of the two density populations, this antigen was detected only in the low-density population. The results indicate that bacterial buoyant density is inversely related to the amount of capsular polysaccharide enveloping the cell and that a determination of the density profile of the bacteria may be used for discriminating strains with an increased pathogenic potential.

Antigens, Bacterial↗
PubMed1987

Band 3 is the basolateral anion exchanger of dark epithelial cells of turtle urinary bladder.

The turtle urinary bladder serves as a model for collecting duct functions in the mammalian kidney. The epithelium of both the turtle bladder and the mammalian collecting duct can generate a steep gradient for H+ ions between blood and urine. Secretion of H+ into the urine is coupled to a basolateral efflux of HCO-3 that appears to be exchanged mainly against Cl-. Here we show that approximately 80% of the dark cells of the bladder contain a 110,000 relative molecular weight (Mr) analogue of the turtle erythrocyte anion exchanger, band 3. The band 3 analogue is confined to the basolateral cell surface and is absent from the apical membrane. A minor population of the dark cells (approximately 20%), which have been previously suggested to represent reverse cells that are involved in HCO-3 secretion rather than absorption, appears not to express a band 3-like anion exchanger, at either the apical or the basolateral membrane. The bladder band 3 protein is colocalized with actin and isoforms of ankyrin (200,000 Mr) and spectrin (230,000 Mr) along the basolateral membrane. Linkage of band 3 via ankyrin to the spectrin-actin lattice may restrict this anion exchanger to the basolateral membrane surface. In view of our previous observation of a band 3-like anion exchanger in the collecting duct epithelium of the rat kidney, these findings point to a common molecular basis for acid-base transport in the mammalian collecting duct and the reptilian urinary bladder.

Animals↗
PubMed1987

Dissolution of mercury from amalgam into saline solution.

Dissolution of mercury from amalgams and some intermetallic compounds found in the amalgam structure, such as gamma 1, gamma 2, and beta 1, was examined during one week of aging in 0.9% NaCl solution at 37 degrees C. The amount of mercury released from gamma 1 (30.2 micrograms/cm2) was at least 13 times that released from amalgam (0.5-2.2 micrograms/cm2) and five times that released from beta 1(5.7 micrograms/cm2). Gamma 2 released the least amount of mercury (0.46 micrograms/cm2). The study revealed that as high as 55% of the mercury ions liberated from the amalgams and the amalgam phases was adsorbed onto the walls of the vials in which the specimens were aged.

Adsorption↗