[Historical development of medical malpractice (author's transl)]

The first legal rules about medical malpractice are to be found in 1700 B.C. (Antique Babylon). Only about 3,000 years later a legally based definition about medical malpractice is given in the "Carolina" and a judgement by experts (medical professional people) is demanded. In about 1630, Paolo Zacchia finds the following statement for medical malpractice: "Medicus errat ommitendo et commitendo". In 1797, Fahner demands a modern definition (still acknowledged today) for medical malpractice and he demands courts for the medical profession. With the Prussian Medical Legislation part of these demands were met in the first third of the 19th century.

Light-dependent plasticity of the morphology of horizontal cell terminals in cone pedicles of fish retinas

Horizontal cell terminals lateral to the synaptic ribbons in goldfish cone pedicles give rise to 0.3 micron long, finger-like extensions in the light-adapted state. These structures, called spinules, disappear almost completely after dark adaptation. The ultrastructure of the horizontal cell terminals is characterized by the presence of occasional microtubules, microfilaments and sparse irregular vesicles; in the dark, large multivesicular bodies can also be found. Two types of membrane densities are described in the horizontal cell terminals, one of which is typically located at the tip of the spinules. Their positive reaction to E-PTA makes it probable that the spinules are synaptic structures. Reconstruction of serial sections shows about 12 spinules per terminal in the light but only two in the dark. Formation and disappearance of the spinules takes about 60 min and involves a transitional stage in the form of a spherical structure. Spinules can be found in five other teleost species, with a darkness-induced reduction in number, but not in the horizontal cell terminals of the mudpuppy, turtle and mammals.

A system of cells in the unstimulated rat brain characterized by preferential accumulation of [3H]deoxyglucose

An autoradiographic technique using cryostat sections is described which permits visualization of a system of small, probably glial cells accumulating 2-[3H]deoxyglucose (2-[3H]DG). These cells are localized mainly in periventricular regions and in certain parts of white matter. Deoxyglucose uptake of these cells is not influenced by various experimental conditions. An attempt to demonstrate by this technique activation of hypothalamic neurosecretory centers following water withdrawal for 3 days was unsuccessful.

Goldfish retina: a correlate between cone activity and morphology of the horizontal cell in clone pedicules

In the cone pedicules, the digitations of horizontal cell process lateral to the synaptic ribbon disappear after dark adaptation. This disappearance is correlated with the loss of color opponency and cone function shown in ganglion cell recordings in isolated retinas. Cone function and color-opponent responses are restored by reapplying background light.

Retinal organisation in goldeye and mooneye (Teleostei: hiodontidae)

This paper presents the results of a comparative investigation of the retinas of two Hiodontids, the goldeye (Hiodon alosoides) and the Mooneye (H. tergisus) employing light and electron microscopy, cell isolation techniques as well as microspectrophotometry. Contrary to the observations of previous workers these species possess a duplex retina. The photoreceptors are bundled in groups of 20 rods and 20 cones. They exhibit features which have hitherto not been observed in vertebrates. These are a) an ellipsoid divided in two parts by the myoid: b) tubules in cone outer segments and, c) large "lateral sacs" (accessory outer segments). Cones are immobile but the rods and epithelial pigment are capable of movement (retinomotor responses). The prominent reflecting layer consists of cuboid and rod-like crystals composed of uric acid. The inner layers are made up of three tiers of large horizontal cells, one of amacrine cells and scarce bipolar and ganglion cells. Bundle density is 1 700 per sq. mm. Roughly, one receptor bundle projects onto one bipolar and one ganglion cell suggesting that each bundle acts as a functional unit. The visual pigment of the mooneye absorbs maximally at 535 +/- 2 nm, and is based on vitamin A2 (porphyropsin). We suggest that all non deep-sea fishes with bundled receptors have duplex retinas and the adaptive mechanisms for vision in turbid waters are based on different morphological means as illustrated by the comparison with Stizostedion.

Photoreceptors and visual pigments in a cichlid fish, Nannacara anomala

Correlation of visual pigment content and photoreceptor cell structure is studied in the cichlid fish Nannacara anomala the retina of which is characterized by simple organization of the outer plexiform layer. The visual cell types consist of long and bulky rods and only two types of cones: equal double cones and short single cones. Both types of cones differ form other known teleost cones in that their outer segments are very slender yet twice as long as the inner segments. The double cones form a square mosaic with four doubles along the sides an a single cone in the center. Four rods usually surround the single cone and a few others lie in the corners of the square. The population densities of photoreceptor cells in the central part of the retina is 45,600 cones and 52,600 rods per mm2. The cone to rod ratio is 1:1.15; the double cone to single cone ratio is 4.07:1. The outer segments of photoreceptors contain four spectroscopic types of pigment: one type in rods with lambda max = 498 +/- 5 nm, one type in single cones with lambda max = 460 +/- 5nm, and one in each member of the double cones with lambda max of 555 +/- 5 and 600 +/- 10 nm. Single cones are found to contain only the blue-absorbing pigment. The double cones, whenever both members are successfully recorded from, appear to use two spectrally different pigments. Based on spectral bandwidth determination, the four pigments are probably of the prophyropsin class, although some admixture (10--20%) of rhodopsin-class pigments is also indicated, especially in double cones.

A microprobe analysis of Gomori-positive glial cells in the rat arcuate nucleus

Astrocytes and microglial cells in the arcuate nucleus of the rat hypothalamus contain lipofuscin-like granules which react with chrome alum gallocyanin and exhibit endogenous peroxidase activity. These granules were assessed with energy dispersive X-ray microanalysis and compared to neuronal dense bodies and glial cytoplasm. The granules are distinguished by a consistent content of sulphur and a frequent presence of calcium. The localization of other elements such as iron, copper, potassium and chlorine is impaired by methodical difficulties. The sulphur content as well as the endogenous peroxidase activity is interpreted as indicating a special variant of lipofuscin. The presence of calcium is discussed with respect to recent concepts of glia as a regulator of the ionic environment of the CNS.

Incorporation of 3H-fucose into nerve and glial cells: assessment by electron microscopic autoradiography

Incorporation of 3H-fucose into hypothalamic tissue of rats was studied between ten minutes and seven days after intraventricular injection. In EM autoradiographs grain densities over perikarya of neurons, astro-, and oligodendroglia, and neuropil were evaluated. Grain densities were consistently higher over both types of glial cells as compared to neurons. The glia/neuron ratio was especially high after short experimental intervals and declined with increasing time intervals. Concomitantly there was an increase of grain density over the neuropil. The discussion concentrates on the methodical aspects which have to be considered in interpreting the autoradiographic data. It is concluded that both astroglia and oligodendroglia exhibit a considerably higher synthesis rate of glycoproteins per unit volume than nerve cells. The implications of the results for the interpretation of biochemical data on glycoprotein metabolism of brain tissue are discussed.

Cone synaptic ribbons and retinomotor changes in the brook trout, Salvelinus fontinalis (Salmonidae, Teleostei), under various experimental conditions

Cone synaptic ribbons in the brook trout were studied and compared with retinomotor responses during a normal 24-h cycle and during 72 h of constant light or darkness. There is a reduction of synaptic ribbons to 65% of the daytime value during a normal night. In the absence of light stimuli, retinomotor movements cease after 20–30 h, whereas rhythmic oscillations of synaptic ribbons, although dampened, persist until the 3rd day. It appears that in the brook trout, which is an arhythmic fish, there is no endogenous control of retinomotor responses and only very little control of synaptic ribbons. The significance of synaptic ribbons for synaptic transmission and of their involvement in endogenous circadian rhythms is discussed.

The feasibility of demonstration of GM- and InV-systems in decaying organs

Gamma-globulin factors (Gm and InV-systems) were determined in 12 cadavers in blood and various organ exprimates (kidney, liver, spleen and muscle). Also checked was the time interval up to which these factors could still be demonstrated in decaying organs. For this purpose blood and portions of the organs were left to decay in plastic containers at an average temperature of 19.1 degree C. Examinations were done with the agglutination-inhibition-test. The exprimates were employed in dilutions 1:10 and 1:20. The serum factors Gm (1), (2), (4), (10) and InV (1) could be demonstrated for varying periods of time. In organs they could be demonstrated for between one and eight weeks. Only factors Gm(1) and Gm(2) could be demonstrated beyond this time. As a rule these serum factors were demonstrable in blood for a longer period of time than in organs; Factor Gm(4) proved to be the most stable one, as it could be demonstrated up to 11 weeks in decaying serum. In 2200 individuals tests with a dilution 1:20 no false positive results were obtained, with the dilution 1:10, however, 5 false positive tests were found. No explanation can be given for the different periods of time for which these factors can be demonstrated under conditions of decay.

Scanning electron microscopy of four teleostean retinas

The morphology of the retinas of the goldeye Hiodon alosoides (fam. Hiodontidae), the brook trout Salvelinus fontinalis (fam. Salmonidae), the yellow perch Perca flavescens and the walleye Stizostedion vitreum (fam. Percidae) was studied by SEM. Semi-thin plastic sections of the same retinas were also examined for comparison. Contrary to observation of earlier authors the goldeye retina was found to possess both rods and cones; in the case of the other three fishes' retinas, present observations correspond to previous ones, adding only details. SEM gives an impressive, three dimensil view of the gross surface features of the retinas. Shrinkage during the processing of the specimens for SEM, while not altering the general topography, does induce artifacts in both plexiform layers.

The connectivity of cones and cone horizontal cells in a mosaic-type teleost retina

A total of 20 Golgi-impregnated cone horizontal cells of Nannacara anomala (Cichlidae) were studied in alternating semi- and ultrathin sections in order to examine their connections with the overlying square mosaic of equal double and central single cones. Cone horizontal cells exhibiting three types of processes: (a) the long horizontal "axon", (b) short horizontal dendrites with a terminal swelling, and (c) cone contacting processes ascending towards the outer plexiform layer. As seen in tangential sections, the latter processes are arranged in the form of two concentric circles including a central "spot". The processes of the inner circle contact the eight double cone pedicles of one square unit: processes of the outer circle contact eight more double cone pedicles which are directly adjacent to the square unit. The central "spot" represents a process which contacts the central single cone. Processes of the inner circle most often terminate in a dichotomous branching which represents the lateral elements to one ribbon synapse, whereas in the outer circle only a single terminal swelling is observed. Because of the mosaic of the cones and the constancy of this pattern of connectivity a model can be constructed where the dendritic fields of the cone horizontal cells overlap to a considerable extent. From this model, it follows that each double cone pedicle is contacted by four different horizontal cells. The functional significance of these findings for color vision is discussed in the light of recent work with the microspectrophotometer characterizing the cone system of this species as bichromatic. The mosaic-like arrangement of the horizontal cell dendrites supports the conclusion that the parallels between the patterns of receptor and horizontal cells are no coincidence but play an important role in lateral inhibition and neural adaptation of the retina.

[Experimental determination of blood-alcohol metabolism with dogs in haemorrhagic shock (author's transl)]

Ethanol at a dosage of 3 g/kg reduced body weight was injected i.v. into mongrel dogs resulting in a blood alcohol concentration of approximately 2.9 mg/ml. One hour after injection the dogs were anaesthetized with halothane-N20/02 and blood was withdrawn until the blood pressure was reduced to 40 mmHg. This usually required removal of about 30 - 40% of the total blood volume. The resulting haemorrhagic shock was ascertained by monitoring blood pH, pCO2, pO2, lactate, pyruvate and blood electrolytes. A blood specimen for enzymatic alcohol determination (ADH) was obtained every 30 min over a period of 3 hours. Compared with equally dosed controls the dogs in haemorrhagic shock showed a significant (p = 0.005) reduction of the blood alcohol decay rate (beta) which is explained by 1) the diminished blood flow through the liver and 2) the hypoxaemic metabolic situation in shock.

Glycoprotein metabolism in the hypothalamus of rat: significance of glial cells

Incorporation of 3H-fucose injected into the CSF was studied in hypothalamus and hypophysis of rats by biochemical and autoradiographic techniques. The concentration of radioactivity was determined as a function of time from 10 minutes to 28 days in the acid soluble and the acid precipitable fraction of homogenates. The incorporated activity was localized by light microscopic autoradiography in several regions of the hypothalamus. The labelled proteins were transported to the pars nervosa at a velocity of 1.1 to 3.3 mm/hr, i.e. in the fast component of the axoplasmic flow. Differences were found between hypothalamic and pars nervosa tissue regarding rates of increase and maximum concentrations of protein-bound radioactivity. Values for both parameters were about 6 times higher in hypothalamus than in pars nervosa. On the basis of the autoradiographic observations it is concluded that this difference may be due to a considerably higher synthesis rate of glycoproteins in glial cells than in neurons.

[Attempted murder with phenprocoumon (marcumar)(author's transl)]

The first known case of attempted murder by means of a coumarine-containing drug, administered by a nurse to her husband, is reported. Small doses of phenprocoumon were regularly added to his food or drinks. He was admitted to hospital with a severe haemorrhagic diathesis which, at first, was thought to be a familial haemorrhagic disease, his mother having died of recurrent hypoprothrombinaemia a few years earlier, the cause of her bleeding trouble never having been established. The wife was sentenced to eight years imprisonment.