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H Stephan

Publications and source records attributed to H Stephan.

At least 91 records · Page 5Linked to original sources
PubMed1985

Volume comparisons in the cerebellar complex of primates. II. Cerebellar nuclei.

Volumes of medial, interposed, and lateral cerebellar nuclei (MCN, ICN, and LCN) were measured in Insectivora, Scandentia, and Primates, including man. The relative size of the nuclei was expressed in size indices. Insectivora had by far the smallest cerebellar nuclei. The simians, in general, had larger cerebellar nuclei than the prosimians, but there was considerable overlap. From Insectivora to man, the MCN was the least progressive and the LCN the most progressive. The indices are expected to reflect the relative size of the three longitudinal zones of the cerebellum (vermis/MCN, pars intermedius/ICN, hemisphere/LCN). They, together with those of the ventral pons and cerebellum (part I), are discussed in relation to the predominant locomotor pattern of a species, and with reference to evolutionary trends in primate phylogeny.

Animals↗
PubMed1985

[Cardiovascular effects of isoflurane-nitrous oxide anesthesia in peripheral and abdominal surgical interventions].

The cardiovascular actions of isoflurane-nitrous oxide anesthesia were studied in 20 patients (age rage 46-76 yr) undergoing laparatomy (group A = 13 patients) or peripheral vascular surgery (group B = 7 patients). Measurements were performed in the awake state, 20 min after induction of anesthesia and during surgical stimulation. Isoflurane produced small changes in heart rate but a significant reduction in mean arterial pressure which was due to a reduction in peripheral vascular resistance and myocardial contractility. During surgical stimulation arterial pressure rose above control values in group A but remained below control in group B. Cardiac index and stroke volume index both decreased after induction of anesthesia in group A and B. During surgical stimulation cardiac index increased in group A due to an increase in heart rate but remained below control in group B, while stroke volume index was reduced in both groups throughout the whole procedure. These results suggest, that contrary to the findings in human volunteers, isoflurane produces a significant cardiovascular depression in aged surgical patient.

Abdomen↗
PubMed1985

[The effect of rewarming of stored blood on plasma value and erythrocytes].

30 units of stored blood of different age were rewarmed from 4 degrees C to 32 degrees C by microwave blood-warmer Infusotherm 407. The resulting damage to blood components and change of function of erythrocytes were compared with those caused by storage of CPD-blood. Dependent on the age of stored blood we found considerable increases in the plasma-levels of potassium, lactate, and free haemoglobin. Compared with cold CPD-blood rewarming of stored blood produced a 7% increase in lactate and a 8% increase in free haemoglobin. There were no changes in platelet and erythrocyte counts, haematocrit, plasma-levels of haemoglobin, electrolytes, cholesterol, blood viscosity, osmotic resistance, and oxygen-binding capacity. As damage of stored blood produced by warming is minimal compared with that produced by storage, the Infusotherm 407 is considered to be a clinically useful blood-warmer.

Blood Cell Count↗
PubMed1985

[Signs of myocardial ischemia based on nocturnal circulatory changes in coronary patients].

During one preoperative night blood pressures, heart rates and changes in ST-segments of ECG were measured at hourly intervals in 20 male patients suffering from a two or more coronary vessel disease. In five patients one or more events of increased myocardial ischaemia were seen in the ECG without any of the patients remembering an attack of angina pectoris. The circulatory function during these periods showed no connection between ST-segment-changes and extremely high or low levels of blood pressure and/or heart rate. Therefore from this investigation nothing can be said about borderline levels of blood pressure and heart rate terminating safe anaesthesia.

Adult↗
PubMed1984

Quantitative neuroanatomy of the brain of the La Plata dolphin, Pontoporia blainvillei.

The brain of the La Plata dolphin, Pontoporia blainvillei, was studied with methods of quantitative morphology. The volumes and the progression indices of the main brain structures were determined and compared with corresponding data of other Cetacea, Insectivora and Primates. In Pontoporia, encephalization and neocorticalization are clearly greater than in primitive ("basal") Insectivora. The indices are in the lower part of the range for simian monkeys. The paleocortex is regressive in accordance with the total reduction of the olfactory bulb and olfactory tract. In contrast to the situation in primates, the septum, schizocortex and archicortex are not progressive in Pontoporia. The striatum and cerebellum are strongly progressive, corresponding to the efficiency and importance of the motor system in the three-dimensional habitat. The diencephalon, mesencephalon and medulla oblongata show considerable progression. Obviously, this is correlated with the extensive development of structures of the acoustic system. The superficial correspondence of the brains of dolphins and primates in relative size and in the degree of gyrencephaly is rather a rough morphological convergence than a sign of functional equivalence. It is coupled to a strongly divergent development of the various functional systems in the two mammalian orders according to their specific evolution.

Animals↗
PubMed1984

Comparison of accessory olfactory bulb volumes in the common tree shrew (Tupaia glis).

The volume size of the accessory olfactory bulb (AOB) of 40 common tree shrews (Tupaia glis) was compared with regard to differences between left and right sides, males and females, and animals born in the wild and those born and raised in captivity. There were no statistically significant differences between the two sides and the two sexes, but a significant reduction of the AOB from wild to captive animals was apparent. This reduction was more pronounced in females than in males and somewhat more pronounced in the inner granular layer (layer 6) than in the other measured components (layers 1 + 2, layers 3-5). No well-founded explanation for this reduction could be given.

Animals↗
PubMed1984

Comparison of brain structure volumes in insectivora and primates. IV. Non-cortical visual structures.

The relative size of the eyes, optic nerves, chiasms and tracts, and of the dorsal nucleus of the lateral geniculate body is distinctly larger in Primates than in (theoretically) isoponderous Insectivora. Within Insectivora, the relative size is lowest in moles, medium in shrews and hedgehog-like tenrecs, and largest in hedgehogs. Within Primates, all relative sizes are on the average larger in simians than in prosimians: the eyes to a small degree, the lateral geniculate bodies moderately and the optic nerves considerably larger. The ratio between eyes and optic nerves is large in night-active primates and distinctly smaller in day-active forms, with no overlap. The only night-active simian (Aotus trivirgatus) is in line with night-active prosimians. The relative size of the non-cortical visual structures in man is in line with that of day-active simians, whereas two of the great apes (orang-utan and gorilla) are relatively low. The size of the visual structures appears to depend mainly on functional requirements and is not, or is distinctly less, related to differences in the evolutionary level. The size of the visual structures of tree-shrews (Scandentia) shows special features which are not found in Insectivora and Primates and is compatible with their separation from these orders.

Animals↗
PubMed1984

Comparison of brain structure volumes in insectivora and primates. V. Area striata (AS).

Volumes of the area striata (area 17, Brodmann) were measured in 44 species of Primates and Scandentia and some of its laminar components in 25 species. The relative size (expressed by size indices) is on the average distinctly larger in simians than in isoponderous prosimians. The average dimensions of increase are 2.5 times for total area striata (ASV), 3.4 times for white matter (ASW), 2.35 times for grey matter (ASG), 1.9 times for lamina 1 (ASG 1) and 2.4 times for laminae 2-6 (ASG 2-6). The high increase of the white matter and the low increase of lamina 1 both correspond to similar results on the total neocortex (Frahm et al., 1982). The molecular layer (ASG 1) is on the average about 12% of the total area striata grey (ASG). The visual cortex thus has a narrower molecular layer than the neocortex as a whole, in which an average of 14% was found. The size indices of man are within the simian range and generally slightly above the simian average. Tree shrews have relatively small visual cortices, but reach into the lower part of the prosimian range. For Insectivora, ASG volumes were estimated from CGL volumes. According to these estimates, the relative ASG size is about 1/90 in shrews, about 1/40 in tenrecs and about 1/10 in hedgehogs that of isoponderous prosimians. In the European hedgehog, the area striata is about 12% of the total neocortex, a value similarly to that found in area measurements by Brodmann (1913). The relative size of the area striata is discussed with regard to functional, ecoethological and phylogenetic considerations. With increasing body weight, the increase in the visual structures, both cortical and non-cortical, is weak when compared with other brain parts and body organs (strongly negative allometry).

Animals↗
PubMed1983

Evolutionary trends in limbic structures.

Structural differentiation and/or size of allocortical limbic structures (hippocampus, schizocortex, septum) are clearly more advanced in higher primates and man than in low (basal) Insectivora. In contrast, olfactory structures (olfactory bulb and olfactory cortices) are clearly smaller in higher Primates than in Insectivora. The opposite trends imply the existence of two functional systems in the allocortex (olfactory and limbic) being predominantly independent of one another. Within the hippocampus the greatest changes from Insectivora through Primates are found in area CA 1. The enlargement of CA 1 is clearly the highest within the hippocampus and its architectonic changes are striking. In the low Insectivora the CA 1 pyramidal layer is very dense and narrow. In Primates the pyramidal cells spread into the stratum oriens, and in man they are finally dispersed over the whole stratum and reach the alveus. In the schizocortex the enlargement of the entorhinal region is accompanied by structural differentiations which are reflected both in laminar and regional complexity.

Animals↗
PubMed1983

Comparison of brain structure volumes in Insectivora and Primates. III. Main olfactory bulb (MOB).

Volumes of the main olfactory bulb (MOB) in 76 species of Insectivora, Scandentia, Primates and Macroscelidea, and some of the laminar components in 34 species were measured. No statistically significant differences were found (1) between the two sides in the 162 individuals and (2) between males and females in the 19 species in which both sexes were examined. In interspecific comparisons the relative size (expressed by size indices) shows a definite tendency to decrease from Insectivora through prosimians and simians to man. The average indices were 100-64-10-3.6, respectively. Scandentia and Macroscelidea have the highest average MOB indices (135 and 166). The relative MOB size is discussed in relation to feeding and social behaviour. It was shown that MOB development is largely linked to dietary adaptations but that its importance in feeding behaviour is paralleled by a similar importance in social behaviour. Within each dietary type, MOB development is associated with the different characteristics of the occupied niche. Among Insectivora, ground-dwelling species occupy the upper, and semiaquatic species the lower positions in the size scale for the MOB. Among Primates, in closely related species, the nocturnal species have in general better developed MOBs than the diurnal species. The composition of the MOB is relatively stable, i.e. the laminar components (layers 1 + 2, 3, and 4-6) show no clear change in their percentage size from well developed to strongly reduced MOBs. Only in the diurnal simians are layers 4-6 relatively small. This corresponds with the general observation (obtained from light-microscopy) that the granular layer (layer 6) is reduced and decomposed in higher Primates, and especially in man.

Animals↗
PubMed1983

[Comparative studies of the psychopathology of bronchial asthma and cystic fibrosis].

Comparative examinations were performed on each N = 36 subjects, with bronchial asthma, cystic fibrosis and healthy controls, with regard to individual psychopathology, family functioning, and the relationship of clinical parameters to psychopathology. Children suffering from cystic fibrosis had the highest prevalence rate of psychiatric disorder. Findings of the psychiatric assessment in general were cross-validated by parent's and teacher's questionnaires. Data relating to family function were less differentiating between the groups. In both groups of diseases significant correlations between clinical parameters and psychopathology were detected.

Adolescent↗
PubMed1982

Comparison of brain structure volumes in Insectivora and Primates. I. Neocortex.

Based on volume measurements the total neocortex increases enormously from the lower ('basal') Insectivora, through prosimians, monkeys and apes up to man. In man it is about 132 times larger than in the average basal Insectivora of (theoretical) equal body weight and 232 times larger than in the insectivoran species which has the least developed neocortex. Within the neocortex the white matter increases more markedly than the grey matter. For man the white matter reaches a value 298 times that of the basal Insectivora and the grey matter reaches a value 198 times greater. Within the grey matter the cell dense layers (laminae 2-6) increase distinctly more than the molecular layer (lamina 1). Thus in man the volume of layers 2-6 is 272 times greater than that in basal Insectivora and the molecular layer is 68 times greater. When related to the total grey matter the percentage of the molecular layer clearly decreases from about 32% in the lower Insectivora to 12% in higher primates.

Animals↗
PubMed1982

Comparison of brain structure volumes in Insectivora and Primates. II. Accessory olfactory bulb (AOB).

A total of 134 individuals from 75 species were investigated with regard to existence and size of the accessory olfactory bulb (AOB). Based on volume measurements the AOB and its three measured components do not show any uniform trend in size changes from lower Insectivora through higher Primates. The investigated structures are in most prosimians clearly larger than in low Insectivora, in most New World simians clearly smaller, and in Old World simians absent. Even within narrowly related groups there may exist strong differences in size and structural differentiation. In AOBs of large relative size, the inner granular layer (layer 6) is relatively larger than in AOBs of small relative size. The variability in size is especially large in those individuals and species with a relatively small AOB. No differences were found between the AOBs (1) of the two sides within the same individual (brain) and (2) between the two sexes within the same species. There is no interdependency in size between MOB (main olfactory bulb) and AOB. The relative size of the AOB is discussed in relation to various ecological and behavioural considerations. No clear relations could be found between the size of the AOB and dietary specialization. A comparison of the relative size of the AOB with activity cycle, sexual behaviour and the use of pheromones in various species of Primates supports the suggestion that the vomeronasal system may be involved in sexual and/or social interaction.

Animals↗
PubMed1981

Biochemical mechanism of infarct size reduction by pyruvate.

We have explored the biochemical mechanism of the infarct size reduction found after intracoronary pyruvate infusion. Using the double infarct model, we simultaneously produced in nine dogs a control- and a therapy-infarct and compared the infarct sizes in each dog after 90 min of occlusion and 90 min of reflow. Intracoronary pyruvate reached the therapy infarct only by way of collaterals but had no access to the control infarct. Tissue levels of reduced nicotinamide dinucleotide (NADH) were measured in control-normal-, therapy-normal-, control-ischaemic-and pyruvate-treated ischaemic areas. In all nine dogs we found a significant reduction in infarct size and NADH levels in the pyruvate-treated areas. Therapy-normal NADH levels fell to 30+/-10% (mean+/-SD) of control-normal levels and therapy-ischaemic NADH levels to 26+/-17% of control-ischaemic levels. We assumed that the infused pyruvate was converted to lactate and at the same time NAD was generated from NADH. Thereby the blockage of glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) by high NADH/NAD-ratios in ischaemic myocardium should be moderated, and ATP production by anaerobic glycolysis stimulated. These small amounts of ATP may be sufficient to guarantee membrane integrity over 90 min of ischaemia and so diminish its harmful effects on the myocardium.

Adenosine Triphosphate↗
PubMed1981

New and revised data on volumes of brain structures in insectivores and primates.

More than 2,000 data on volumetric measurements of 42 structures in a variety of up to 76 species (28 insectivores, 21 prosimians, 27 simians) are given. All volumes measured in serial sections were converted to fresh volumes of a brain having a standard size within a given species. The date are available to all scientists for comparison and analysis. To allow critical evaluation, details on fixation and preparation, on determination of fresh brain weights and volumes of brain parts and on intraspecific variability are given.

Animals↗