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Biomedical subjects

S Lange

Publications and source records attributed to S Lange.

At least 19 recordsLinked to original sources

[Quantitative computerized tomographic bone mineral analysis in patients treated by regular haemodialysis (author's transl)].

Quantitative bone measurement has been done on the forearms of 40 patients (aged 20 to 67 years) undergoing long-term haemodialysis treatment. It turned out that trabecular bone shows a more substantial change of the mineralization than does cortical bone. In comparison to an age-correlated undialysed normal range the mean trabecular bone density was found decreased up to 100 percent, whereas cortical bone with a mean demineralization of 10 percent did not appear to be affected by the renal osteodystrophic alterations to that degree. Finally the results show that throughout the course of dialysis treatment there was a trend toward distinct loss of bone mineral with time. No relationship could be demonstrated between the bone mineral values and various biochemical parameters. The estimation of osseous mineral content in both trabecular and cortical bone was done with the aid of an improved computer assisted tomographic method introduced by Rutherford and Pullan.

Adult

[The kinetics of contrast media in cerebral tumours (author's transl)].

The increase in density of cerebral tumours following intravenous injection of contrast media was measured by computer tomography and was evaluated quantitatively. The density increase of 158 tumours five minute after injection was between 0 and 29 CT units. There are considerable variations in density increase of various types of tumour, but the scatter is so wide as to preclude a diagnosis of tumour type. In 75 tumours repeated measurement of contrast changes were carried out for two hours following the injection. Again the variation differs with different types of tumour, but is not characteristic enough for exact clinical diagnosis. In 26 patients contrast concentrations were measured in the tumour and the blood and a pharmaco-kinetic compartmental analysis was carried out. In some tumours contrast changes can be explained by a single compartment model, whereas in others a two compartment model is necessary. Certain conclusions regarding the mechanism of contrast uptake can be reached.

Absorptiometry, Photon

Local cholera immunity in mice: intestinal antitoxin-containing cells and their correlation with protective immunity.

Methods for light and electron microscopic identification and characterization of intestinal cholera antitoxin-containing cells (ACC) using peroxidase-labeled immunoreagent are described and used to study the ACC response in mice after immunizations with cholera toxin. Specific ACC appeared in significant numbers after two oral immunizations and increased six- to eightfold with two additional oral boosters, whereas further oral immunizations caused no additional stimulation. Intravenous immunizations had to be repeated seven times before ACC could be detected. After two oral immunizations, most of the ACC were found in the proximal part of the small intestine and no ACC were seen in the colon. This uneven distribution of ACC within the small intestine was eliminated after four oral immunizations, when ACC could also be detected in the colon. The ACC response after four oral immunizations demonstrated a peak at 4 days with far fewer cells present at 2 and 7 days. Electron microscopic studies showed that the ACC were mature plasma cells with the staining localized to the endoplasmic reticulum. Regression analysis of the relationship between the number of ACC and the magnitude of protective immunity against intestinal challenge with cholera toxin indicates a highly significant correlation (r = 0.91, P less than 0.001).

Animals

Chlorpromazine reverses diarrhea in piglets caused by enterotoxigenic Escherichia coli.

The effect of chlorpromazine (CPZ) on diarrhea caused by enterotoxigenic Escherichia coli was tested in piglets since CPZ has been shown to be a potent antagonist to enterotoxins in vitro in a cell system and in vivo in a mouse model. Experimental diarrhea was induced in three litters of newborn piglets which were infected by mouth with 2 x 10(9)E. coli bacteria, which produce heat-labile (LT) and heat-stable (ST) enterotoxins. Treatment with CPZ given intramuscularly 1 h after the onset of diarrhea reversed fluid secretion in small intestine as well as dehydration, as judged by clinical criteria. A dose of 5 mg of CPZ per kg of body weight completely normalized the intestinal-fluid content measured 4 h after diarrhea developed, whereas 1 to 2 mg of CPZ per kg of body weight was somewhat less effective but still caused significant reduction of fluid (P < 0.001). Studies with radioactive [(35)S]CPZ showed preferential and dose-dependent uptake of (35)S in the intestinal mucosa, the radioactivity being evenly distributed in the membranes of both crypt and villus cells. The enzyme adenylate cyclase, which probably mediates the cellular effects of LT, was shown to have two- to threefold higher activity in the infected than in the uninfected animals. This activation was reduced about 50% by the CPZ treatment (2 mg/kg of body weight). In a preliminary field trial the effect of CPZ was tested in a spontaneous outbreak of diarrhea in piglets due to enterotoxinogenic E. coli. The animals were treated either with oral electrolyte solution and standard antimicrobial agents only (controls) or with 1 mg of CPZ per kg of body weight intramuscularly in addition to this treatment. The mean duration of diarrhea in CPZ-treated animals was significantly shorter, 4.1 h (n = 23), than that in controls, 7.2 h (P < 0.05).

Adenylyl Cyclases

Studies on the conjugation of horseradish peroxidase to immunoglobulin G via glutaraldehyde.

Horseradish peroxidase was conjugated to immunoglobulin G via glutaraldehyde by a two-step procedure using an increasing excess of peroxidase in the second step reaction. The yield of conjugated monomeric IgG and the amount of free IgG were analyzed by SDS-polyacrylamide electrophoresis and gel-filtration. The antigen binding capacity of the enzyme-antibody conjugates was evaluated by radial immunodiffusion. Conjugation of peroxidase to IgG with a 1:20 molar:molar excess of glutaraldehyde-activated peroxidase resulted in a high yield of conjugated IgG without any detectable amounts of polymers of IgG or residual free IgG. The antigen binding capacity of the conjugate varied between different antigen-antibody systems, but in general it was not significantly different from that of native IgG. The enzyme activity was reduced to 70% of the activity of native peroxidase.

Aldehydes

[Thorotrastoses--viewed in retrospect (author's transl)].

Thorium dioxide (Thorotrast) was used as a contrast medium from 1930 to 1945. It gave excellent contrast and was well tolerated during the application, but due to its radioactivity and its long biological half life it caused various late complications as fibrosis and malignant tumors. The late side effects of the substance are reported on, and the most frequent complication--the induction of hepatomas--is illustrated by two cases.

Angiography

[Fracture of skull-comparative study of conventional and computer-assisted roentgenological examination (author's transl)].

Using a skull like phantome imaging characteristics of conventional x-ray technique and computerized tomography are compared. The contrast transfer function of x-ray films proofs to be superior, whichis due to overrange artefacts found in computerized tomography. Only 8 out of 50 skull fractures diagnosed by plain film technique were identified on computer-tomograms. Even though CT technique is excellent for the detection of intracranial lesions, fractures are more easily seen on conventional films. This is especially important for analysing size and site of impression fractures.

Humans

[Local variation of brain structures related to C. T. reference line (author's transl)].

Median sagittal sections of the cranium of 18 males and 7 females aging from 42 to 74 years were investigated. The distance of brain structures from the skull varied about 11 to 22 mm if the orbitomeatal line is used as reference. A correlation coefficient below 0.5 is found between distances on the outside of the skull and on the median sagittal section as well in horizontal as in the vertical direction. The statistical deviation of the outline of the brain is less extended with an intracerebral reference line than with reference points on the outer surface of the skull. The localization of several telencephalic parts are correlated with the inclination angle of the brain stem. The long axis of the brain stem therefore appears to be the best reference line for localization of brain structures.

Adult

The effect of graded immersion on heart volume, central venous pressure, pulmonary blood distribution, and heart rate in man.

The present experiments have been conducted to study the immediate effects of graded immersion on the central circulation. When taking heart volume as an indicator, it was found that immersion to the diaphragm of a standing subject produces the same changes as assumption of the supine posture. Heart volume increases by approximately 130 ml. When the water level is raised to the neck, an extra pressure corresponding to a water column extending from the diaphragm to the surface of the water of approximately 25 cm H2O forces blood into the thorax. The heart becomes distended by an additional 120 ml. Correspondingly the central venous pressure at the height of the right atrium increases from 2.5 to 12.8 mm HG when the water level rises from the diaphragm to the neck. The greater filling of the pulmonary circulation is accompanied by a decrease in vital capacity and visualized by scintigrams. The preferential increase in blood volume of the apical regions is striking. When raising the water level from the symphysis to the xiphoid heart rate falls by about 15%.

Adult

Time course of cardiac distension with rapid immersion in a thermo-neutral bath.

13 subjects standing in a narrow upright tank were exposed to rapid water immersion up to the neck. The tank was filled from an elevated reservoir in less than 4 s. In 8 subjects heart size was measured by Roentgen-cinematography combined with video tape recording. Planimetry of the diastolic postero-anterior area of the heart showed an average increase in heart size of 30% within 6 s. In 5 subjects central venous pressure and the height of hydrostatic pressure in the tank were recorded. The two pressures rose and fell simultaneously without delay when the hydrostatic pressure exceeded the level of the diaphragm. Rapid immersion caused a fall in heart rate of approximately 20%. The findings speak in favor of the concept that the right heart does not constitute a resistance and that the pulmonary circulation and the systemic capacitance vessels form a functional unit.

Adult

The diagnostic value of CT for radiotherapy of cerebral tumors.

The paper deals with CT followup studies on 73 patients with cerebral tumors who received radiotherapy. The value of CT for the indication of radiotherapy, for followup therapy and for the demonstration of therapeutic success are discussed. Since the cerebral tumors become visualized by means of CT in their entire extent and can be differentiated from perifocal edema, the question arises whether radiotherapy should consist of higher doses in the future. It is also suggested that the "clinical malignancy" may be used to compare the behavior of cerebral tumors when there is no exact histological classification. The possible histopathological effects of radiotherapy (edema, necrosis) and their demonstration by CT are discussed.

Adult

Stimulation of immune reactivity by methoxy-substituted glycerol ethers incorporated into the feed.

In mice, the plaque-forming cell response to sheep red blood cells was stimulated by a mixture of methoxy-substituted glycerol ethers isolated from Greenland shark liver oil and by synthetic 1-0-(2-methoxyhexadecyl)-glycerol, given in the diet. In preliminary experiments, this synthetic compound also increased the ability of parental spleen cells to induce graft-vs.-host reactions in F1 hybrid mice. Glycerol ethers occur in the bone marrow fat of mammals and in the membrane phospholipids. It is postulated that the methoxy-substituted glycerol ethers supplied in the diet may stimulate the bone marrow and/or may be incorporated into membrane lipids, thereby changing the structure and function of the membranes.

Animals

Axial transverse computerized tomography in 73 glioblastomas.

Among 2,600 patients, examined by computerized tomography, 404 had brain tumours, which were gliomas in 150 cases. There were 73 glioblastomas. Examination was performed according to Ambrose's method using an intravenous injection of 1 ml 60% contrast medium per kg body weight. Thus 98% of all gliomas could be demonstrated. Glioblastomas are shown in three different forms: an annular type (55%), a nodular type (18%), and a combined type (27%). Perifocal oedema is found in 88% of glioblastomas. The oedema most frequently belongs to grade II or III. Differentialdiagnosis of gliomas, abscess, metastases and other tumours with central necrosis are discussed.

Astrocytoma

[Bone density measurements by computer tomography (author's transl)].

The suitability of the E.M.I. mark I computer scanner for carrying out bone densitometry has been tested, using the forearm. Within the region of interest there was an almost linear relationship between CT densities and the concentration of the bone equivalent substance K2HPO4. By means of a special computer programme, the spongiosa and cortex of both forearm bones could be analysed quantitatively. The reproducibility of the results (coefficient of variation 5%) was similar to that of other procedures in current use. The advantage of the method lies in the fact that it is possible to estimate the spongiosa and cortex separately. Investigations on patients with normal bones have shown that senile demineralisation affects the cortex most severely. On the other hand, in renal osteopathies of chronically dialysed patients, demineralisation in the forearm predominantly involves the spongiosa.

Absorptiometry, Photon

Protective antitoxic cholera immunity in mice: influence of route and number of immunizations and mode of action of protective antibodies.

An adult mouse model has been elaborated for studies of experimental cholera (Vibrio cholerae enterotoxin-induced intestinal secretion) and protective antitoxic immunity in either ligated small bowel loops or intact small intestine. Mice of different inbred strains varied markedly in intestinal susceptibility to toxin, C57B1 being the most sensitive strain tested. Fluid accumulation started within 1 h after the inoculation of toxin and was maximal after 5 h, whereafter recovery gradually ensued. The dose-response curve was sigmoid, the ED50 of crude toxin being equivalent to about 0.1 microgram purified toxin/cm in the loops and 0.3 microgram/cm in the nonligated intestine. Two peroral (p.o.) immunizations induced significant protective immunity which increased markedly after two further immunizations by the same route. Additional p.o. immunizations did not appreciably enhance the protective immunity any further. Intravenous (i.v.) vaccination had to be repeated more than 5 times before intestinal immunity could be observed. No correlation between serum antitoxin titers and protective immunity was found. Electron microscopic examination revealed that whereas peroxidase-coupled cholera toxin bound tightly to intestinal microvilli from unimmunized or 5-times i.v. immunized mice it did not bind to the microvilli of p.o. immunized animals. The data thus suggest that the protective immunity is mediated exclusively by locally produced antibodies which prevent the binding to toxin to the gut epithelium.

Administration, Oral