In an in vitro study, 10 gallbladders of adult pigs and 6 gallbladders of lambs, all removed immediately after slaughtering, were stimulated in a water bath by electric means to induce active contraction. Gallbladder emptying was followed by ultrasonography employing five measurement procedures: (1) gallbladder width, (2) longitudinal planimetry, (3) transverse planimetry, (4) ellipsoid method, and (5) sum of cylinders method. In an in vivo investigation, gallbladder emptying of 30 volunteers (12 healthy subjects, 18 diabetics) was evaluated in the same way after ingestion of a fatty meal. Gallbladder width was found to be unsuitable to estimate the decrease in gallbladder volume due to a nonlinear relation of the parameters. Longitudinal planimetry tended to be less valid than transverse planimetry in assessing gallbladder volume reduction. The most valid estimation of gallbladder volume decreases was obtained by the two three-dimensional procedures. However, in neither in vitro nor in vivo could a significant difference between the sum of cylinders method and the ellipsoid method in determining relative volume reduction be established. We conclude that a three-dimensional measurement procedure should be used for valid assessments of gallbladder motility. However, according to our data there is no advantage in using the time-consuming sum of cylinders method compared to the simple ellipsoid method.

Adult↗

PubMedDate not supplied

Effects of acetylcholine on the regional distribution of microspheres in the skeletal muscle of the cat.

The present experiments were performed to study the question whether intraarterially infused acetylcholine changes in local tissue perfusion of the skeletal muscle. In experiments on cats the triceps surae muscles were isolated. While acetylcholine (0.5 mug/kg X min) was infused intraarterially on one side, the opposite side was taken as control. 4 minutes after the start of the infusion non-radioactive microspheres of 15 mum diameter were injected into the ascending aorta. Subsequently the muscles were freeze-sectioned into 1.0 mm thick slices and cleared by sodium hydroxide and glycerine. The concentration of microspheres per mm3 was measured in representative cross sections of the muscle. Higher concentrations of microspheres were observed in the proximal than in the distal slices of the acetylcholine-treated side. The distribution of microspheres was found to be different in the segments as well: higher values were found in the central than in peripheral segments. The untreated side showed a qualitatively similar state. The differences in the distribution pattern, however, were smaller than in the acetylcholine-treated muscles. It is concluded that the increased inhomogeneity of the regional perfusion observed in this study during vasodilation corresponds to the results reporting a changed nutritive tissue perfusion during an acetylcholine treatment.

Acetylcholine↗

PubMedDate not supplied

Density of plasma-perfused capillaries in the rat heart during carbocromene-induced vasodilation.

Urethane-anesthetized thoracotomized rats were used to ascertain whether the density of plasma-perfused capillaries increases in the heart during pharmacologically induced vasodilation. Carbocromene, in a dose of 3.0 mg/(kg x min) i.v., infused for 5 min, raised coronary blood flow from 6.2 +/- 0.6 to 15.6 +/- 0.1 ml/(min x g); heart rate and blood pressure were only slightly changed. Capillary density was determined by timed infusions of a plasma label (FITC or RB 200 coupled with gamma-globulin), infused for different periods of time in the same animal. No significant difference could be observed in the number of capillaries marked for 10 min in the carbocromene-treated rats as compared to the controls (carbocromene-treated rats: 3,630 +/- 90 cap/mm2 subepicardium, 3,360 +/- 70 cap/mm2 subendocardium; controls: 3,750 +/- 140 cap/mm2 subepicardium, 3,210 +/- 90 cap/mm2 subendocardium). In those rats treated with the vasodilator the filling of the microcirculatory system was nearly complete within a labelling period of 1 sec (3,500 +/- 170 cap/mm2 subepicardium, 3,070 +/- 110 cap/mm2 subendocardium), whereas significantly lower values were found when the dye was infused for 1 sec in the controls (2,560 +/- 460 cap/mm2 subepicardium, 1,960 +/- 400 cap/mm2 subendocardium). The results indicate that the filling of the cardiac microcirculatory system is accelerated by a pharmacologically induced vasodilation, the maximal density of plasma-perfused capillaries is not raised, however.

Animals↗

PubMedDate not supplied

Effects of isoprenaline on functional capillary density in the subendocardial and subepicardial layer of the rat myocardium.

The functional capillary density in subepicardial and subendocardial layers of rat heart was measured during rest and during isoprenaline-induced (5.0 microgram X kg-1 X min-1, i.v. over 3 minutes) cardiac stimulation. For determination of the number of perfused capillaries, a fluorescent dye (thioflavine S) was infused into the left atrium; 1, 3, 5 and 10 sec, respectively, after starting dye application, hearts were excised and rapidly cooled down to -50 degrees C. In histological sections capillaries which had been perfused during the dye infusion could be identified and counted. An increase in the number of stained vessels was found in both layers of the myocardium when the time of dye exposure was prolonged. Under these conditions the rise was much smaller in isoprenaline-treated animals, this effect being most marked in the subendocardial layer (3560 +/- 199 cap./mm2, control group; 2190 +/- 30 cap./mm2, isoprenaline-treated group; dye exposure 10 sec). Isoprenaline - at the dose used - induced an increase in total blood flow (3.7 +/- 0.6 ml X min-1 X g-1, control group; 6.8 +/- 0.7 ml X min-1 X g-1, isoprenaline-treated group), however, with a relatively less pronounced increase in the subendocardial blood flow (subendocardial/subepicardial flows: 1.08 +/- 0.13, control group; 0.66 +/- 0.01, isoprenaline-treated group). These results favour the view that isoprenaline-induced relative reduction in the subendocardial blood flow is due to disturbance of perfusion pressure and extravascular compression rather than to exhaustion of the myocardial capillary reserve.

Animals↗

PubMedDate not supplied

Dilatatory capacity of the coronary system in the anesthetized rat.

The minimal coronary vascular resistance was measured in anesthetized rats. For determination of coronary flow a tube system was inserted which directed the blood from the left carotid artery via the right carotid artery into the ostium of the left or the right coronary artery. A drop chamber in the shunt system enabled flow measurement. Maximal vasodilatation was induced by intra-arterial infusion of adenosine. In non-thoracotomized rats vascular resistance decreased to 20.6% and 20.3% of control values in the left and right coronary artery, respectively (23.8 to 4.9 18.2 to 3.7 mmHg X ml-1 X min X g). Thoracotomy led to increased control values (29.3 mmHg X ml-1 X min X g, right coronary artery). Minimal resistance in this latter group was nearly as low as in the closed-chest rats (4.8 mmHg X ml-1 X min X g). It can be assumed that the coronary dilator reserve in the rat lies within the same range as that of larger species e.g. dogs.

Adenosine↗

PubMedDate not supplied

Does digoxin sensitize left ventricular mechanoreceptors?

Afferent nerve fibre activity from left ventricular mechanoreceptors was recorded in 10 anaesthetized cats before and after two intravenous injections of 15 micrograms/kg digoxin at 1 hour interval. These receptors are activated by coronary artery occlusion and induce a depressor cardiovascular reflex resulting in bradycardia and hypotension. Neither the spontaneous activity of the receptor's afferent nerve fibres nor their maximum activity during temporary coronary artery occlusion was affected by digoxin. The results show that digoxin in therapeutic doses has no sensitizing effect on left ventricular mechanoreceptors with vagal afferent fibres. The sensitization of cardiopulmonary baroreflexes by digitalis glycosides shown in previous investigations is thus more likely to be mediated by a central nervous effect of the drug.

Animals↗

PubMedDate not supplied

Actions of diazepam on the discharge pattern of phrenic motoneurones in rats.

Explore the source record for details and available documents.

Action Potentials↗

PubMedDate not supplied

Studies of the oxysterol inhibition of tumor cell growth.

The oxysterols 3 beta-hydroxy-5 alpha-cholest-8-en-11-one, 3 beta-hydroxy-5 alpha-cholest-8-en-7-one, 3 beta-hydroxy-5 alpha-cholest-8(14)-en-7-one, 3 beta-hydroxy-4,4'-dimethylcholest-5-ene-7 one, 4,4'-dimethylcholest-5-ene-3 beta, 7 alpha-diol, 4,4'-dimethylcholest-5-ene-3 beta, 7 beta-diol, lanost-8-ene-3 beta, 25-diol, 25-hydroxylanost-8-en-3-one, 9 alpha, 11 alpha-epoxy-5 alpha-cholest-7-en-3 beta-ol, 3 beta-hydroxycholest-5 alpha-en-22-one, and 3 beta-hydroxycholest-5-en-22-one oxime were evaluated with respect to their ability to inhibit cell growth. All of the sterols were found to possess cytotoxicity when incubated with hepatoma (HTC) and lymphoma (RDM-4) cells in culture at 10-30 microM concentrations.

Animals↗

PubMedDate not supplied

The influence of neuropeptide Y and norepinephrine on ovulation in the rat ovary.

Neuropeptide Y (NPY) was measured in tissue extracts from ovaries of rats treated with pregnant mare serum gonadotropin (PMSG). The extracted NPY-immunoreactive material was identical to synthetic human NPY with regard to size and hydrophobicity as evaluated by gel filtration and high performance liquid chromatography. The concentration of NPY was related to the estrous cycle and a maximum was observed in relation to the endogenous luteinizing hormone (LH) peak. NPY immunoreactivity was demonstrated by immunohistochemistry to be localized within nerve fibers supplying blood vessels and follicles. The increase in the NPY content could not be related to accumulation around specific ovarian structures. Employing an in vitro set-up, NPY (10(-7) M) was unable to induce ovulation and did not increase the ovulation rate in LH-stimulated ovaries. The combination of NPY (10(-7) M) and NE (10(-7) M) did not significantly increase the number of ovulations compared to that induced by NE (10(-7) M) alone. In conclusion, NPY content in the ovary is related to the estrous cycle, but NPY does not seem to have any direct effect on the ovulatory process.

Animals↗

PubMedDate not supplied

Deaths resulting from drugs of abuse.

This report covers 40 narcotics fatalities from the Northbaden are (Federal Republic of Germany) that came to the Institute of Forensic Medicine, Heidelberg University for autopsy in the years of 1968-1973. Information is given on pathological anatomic and toxicologic findings. A biographical, sociological, psychiatric and criminological catamnesis gave important insight in determinants, motivations, development and course of drug dependence in this area. Basic details are shown and critically evaluated.

Adolescent↗

PubMedDate not supplied

Rib-cage injuries indicating the direction and strength of impact.

The hardness and loading capacity of hundreds of rib pairs have been tested and compared with the results of about 200 tests concerning belt-protected human cadavers. Rib fractures exhibit patterns that indicate the direction and strength of impact. Differences are seen between static and dynamic loading. Deformation of the loaded rib cage can be demonstrated by X-ray examination.

Accidents, Traffic↗

PubMedDate not supplied

Use of radiographs in the forensic autopsy.

The X-ray examination of corpses is a most useful tool in the field of medicolegal diagnosis. Sometimes the cause of death can already be seen before autopsy. The following modes of application are reviewed: search for foreign bodies, identification of poison, air-embolism, pneumothorax, air-filled lungs and gastro-intestinal organs in newborns, diagnosis of tuberculosis in corpses, visibility of hidden fractures, structure of bones as a factor of biomechanical load capacity, identification and determination of age and experimental research with corpses.

Age Determination by Skeleton↗

PubMedDate not supplied

Harman (1-methyl-beta-carboline) in blood plasma and erythrocytes of nonalcoholics following ethanol loading.

Eleven subjects having no history of substance abuse or dependence who agreed to abstain from alcohol for one week prior to the investigation were selected to participate in the present study. On two occasions, separated by four to six weeks, blood was drawn over an 8-hour period (0, 0.5, 1, 2, 4 and 8 hours). On the first occasion, subjects were given an oral dose of ethanol (1 g/kg) after the first blood sample was drawn (ethanol-loading condition). On the second occasion no ethanol was administered (control condition). On both occasions no detectable harman was found in the plasma of subjects. In the control condition harman was detected in the erythrocytes of 7 subjects which remained relatively stable over time. In the ethanol-loading condition, however, a time-dependent increase of harman in the erythrocytes was observed. The concentration of ethanol, acetaldehyde, and erythrocyte-harman showed a parallel trend over time. These findings demonstrate an increased level of harman following ethanol loading in humans.

Acetaldehyde↗