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Biomedical subjects

A Hess

Publications and source records attributed to A Hess.

At least 91 records · Page 5Linked to original sources
PubMed1981

Localization of noradrenaline and serotonin in nerves in the pineal gland of rats and guinea-pigs studied by glyoxylic acid histofluorescence and electron microscopy.

The nerves in the pineal gland of the rat and guinea-pig contain both noradrenaline and serotonin and fluorescence intensely after histofluorescence procedures. Vesicle-filled terminals in the perivascular space of the pineal body contain numerous clear and dense-cored vesicles. A 5 mg/kg dose of reserpine causes disappearance of histofluorescence from the pineal nerves and a virtual elimination of dense-cored vesicles from vesicle-filled terminals. A 1 mg/kg dose of reserpine results in loss of fluorescence and virtual depletion of dense cores in nerves in the rat, but the guinea-pig pineal nerves continue to fluoresce lightly and the dense-cored vesicles are still present but reduced to about 1/3 in number. Subsequent treatment of lightly reserpinized guinea-pigs with p-chlorophenylalanine, a specific depletor of serotonin, results in disappearance of fluorescence in nerves in the pineal gland and virtual depletion of the remaining dense cores. A dose of 1 mg/kg reserpine succeeds in depleting noradrenaline from most peripheral nervous structures of the guinea-pig. Hence, the remaining monoamine in guinea-pig pineal nerves after depletion of noradrenaline appears to be serotonin located in the remaining dense-cored vesicles. Since, in lightly reserpinized guinea-pig pineal nerves, a number of dense-cored vesicles containing serotonin are still present after depletion of noradrenaline, it is suggested that noradrenaline and serotonin are not in the same vesicles at the same time.

Animals↗
PubMed1981

Transmission of hepatitis-B-virus by pleural effusion containing Dane particles.

Hepatitis-B-surface antigen HBSAG), hepatitis B-e antigen (HBe(HBeAG), and anti-HBc and Dane particles were demonstrated in pleural effusion obtained from an individual with a protracted course of an acute type B hepatitis, Pleural effusion was found to be unrelated to hepatitis-B-virus (HBV) infection. A physician who injured herself with a needle contaminated with pleural effusion experienced asymptomatic acute type B hepatitis.

Adult↗
PubMed1980

[ALL-study series of Hamburg (author's transl)].

From 1971 through 1979 145 newly diagnosed patients with ALL have been treated within a series of consecutive studies. Study I corresponds to branch A of the 1972 DAL study. In the following studies the induction therapy has been escalated stepwise with the continuation therapy remaining mostly unchanged. Thereby the disease free survival rates increased from 75 to 94% after one year and from 32 to 60% after 4 years respectively. CNS-relapse mainly occurred during the second year of treatment. Their incidence rose from 5% to more than 10% in connection with a change in the radiation portal. Since another correction of the portals with special consideration of the paramedian lower border of the skull base no more CNS-relapses have been observed until now. The actual cooperative ALL-study follows a modified BFM-protocol with postponed asparaginase in hoping to achieve reduced initial morbidity and at least equal good survival times.

Child↗
PubMed1979

Response of mouse intestine to 14 MeV neutrons.

At the Hamburg-Eppendorf Hospital neutron facilities the relative biological effectiveness (r.b.e.) of d,T-neutrons was determined with respect to survival of mouse intestinal crypts. (CBA/Rij x C57BL/Rij)F1 mice were irradiated to the whole body at different depths inside a tissue-equivalent phantom. Irradiations were carried out with a collimated neutron beam at about 6 rad/min given in single doses ranging from 450 to 1000 rad. For reference, gamma-rays from a 60Co therapy unit were used. The number of surviving intestinal crypts per circumference of the jejunum was determined 3 1/2 days after irradiation according to the method of Withers and Elkind. The number of surviving stem cells was calculated on the basis of Poisson statistics. The doses necessary to reduce survival to ten crypt stem cells per circumference amounted to 689 +/- 19 rad for neutrons and 1449 +/- 29 rad for 60Co gamma-rays. From these figures an r.b.e. of 2 . 1 +/- 0 . 1 is obtained. Measurements at different depths in the phantom did not show any variation of r.b.e. with depth along the axis of the neutron beam.

Animals↗
PubMed1979

Lipoquinones of some spore-forming rods, lactic-acid bacteria and actinomycetes.

The respiratory quinones of 73 strains of Gram-positive bacteria including spore-forming rods, lactic-acid bacteria and actinomyctes were examined. Menaquinones with seven isoprenoid units (MK-7) were the main quinone type found in representatives of the genus Bacillus and in Sporolactobacillus inulinus. However, a strain of B. thuringiensis produced MK-8 in addition to MK-7, and strains of B. lentus and B. pantothenticus appeared to produce MK-9 and MK-8, respectively, with no MK-7. In the clostridia and lactic-acid bacteria, no quinones were found, except in Pediococcus cerevisiae NCTC 8066 and Lactobacillus casei subsp. rhamnosus ATCC 7469, which contained menaquinones, and Streptococcus faecalis NCTC 775 and HIM 478-1, which contained demethylmenaquinones, in relatively low concentrations. Menaquinones were also found in the actinomycetes (except Actinomyces odontolyticus and Bifidobacterium bifidum which did not produce any quinones) and in Protaminobacter alboflavus ATCC 8458, the so-called Actinobacillus actinoides ATCC 15900 and Noguchia granulosis NCTC 10559.

Actinomycetales↗
PubMed1979

The effect of an analyzed deuterium ion beam on the lifetime of TiT targets used at the fast neutron therapy facility (DT, 14 MeV) Hamburg-Eppendorf.

Report on experiments performed with mixed or analyzed deuterium ion beams incident on TiT targets at the neutron therapy facility Hamburg-Eppendorf. Bombarding a TiT target area with all separated atomic and molecular ions of an analyzed deuterium ion beam at different beam spots, the "initial" half-life of the used tritium target increases with a factor of more than three as against the half-life obtained with a mixed deuterium ion beam at a single beam spot. In this case, the effective target current is not reduced and in the same order as that for a mixed deuterium ion beam. Using the atomic deuterons only, the increase of the "initial" half-life is far longer yet, but the loss in target current is about 50% dependent on the reduction of molecular deuterium ions. These facts are most important for the economy of this type of neutron therapy facilities clinical work.

Deuterium↗
PubMed1978

A simple procedure for distinguishing dopamine from noradrenaline in peripheral nervous structures in the fluorescence microscope.

The difference between dopamine and noradrenaline after ordinary histofluorescent procedures cannot be discerned. Reserpine treatment results in depletion of fluorescent material from dopaminergic and noradrenergic peripheral nervous structures. Administration of reserpine, 1 mg/kg subcutaneously for 3 hr, followed by intraperitoneal injection of 200 mg/kg levodopa methyl ester on 0.9% saline for 90 min, result in refluorescence of dopaminergic (glomus cells of the carotid body) but not noradrenergic (sympathetic ganglion cells, nerves of atrial heart muscle and blood vessels) structures. Hence, the sequential administration of these readily available drugs and the application of ordinary histofluorescent techniques result in a simple procedure for distinguishing dopamine from noradrenaline in the fluorescence microscope.

Dopamine↗
PubMed1978

The neutron therapy facility (DT, 14 MeV) at the radiotherapy department of the university hospital Hamburg-Eppendorf.

The neutron therapy facility at the Radiotherapy Department of the University Hospital Hamburg-Eppendorf is described. This unit has been developed for clinical purposes according to the initiative and conception of the radiotherapist by AEG/Fed. Rep. of Germany and RDI/USA since 1969. The installation was completed at the beginning of 1974. Special treatment head and bed systems allow isocentric treatment and arc or multiple port therapy. For routine work operation conditions of 8 to 12 mA total beam current and 500 kV accelerating voltage are used. The neutron output at 12 mA is about 3.5 x 10(12) n/s giving a phantom dose rate of more than 20 rad/min for a field size of 17.8 x 17.8 cm2 at 80 cm source-skin distance. Technical installations for improvement of dose rate and half-life of the target are planned. Results of physical measurements about neutron energy distributions, contributions from neutrons and gamma-rays to the total absorbed dose, build-up effect, axial and lateral dose distributions as well as isodose profiles for different field sizes in a homogeneous phantom are presented. Bewteen February 1976 and November 1977 up to 180 patients have been treated.

Mathematics↗
PubMed1977

Chronically denervated rat carotid bodies.

The ninth nerve was severed and the rat carotid body studied in the light and electron microscopes and after formaldehyde-induced fluorescence for its catecholamine content from 3 weeks to 13 months after operation. Minimal changes in the carotid body were observed. Hyperthrophy of the capsule cell was noticed up to about 2 months, after which time these cells appeared normal. Lysosomes in the capsule cells occurred more frequently and were larger than in normal carotid bodies. Discernible pathological alterations did not occur in the glomus cells, despite the absence of afferent terminals upon them. Atrophy of the carotid body was not noticed. The catecholamine content of the denervated carotid body was comparable to its innervated control and no nerve terminals were found on the glomus cells. Autonomic ganglion cells intrinsic to the carotid body varied in number from 1 to 8 and in location. The glomus cells do not receive any significant autonomic innervation, and the ganglion cells in the carotid body, perhaps sympathetic, probably innervate blood vessels. It is concluded that deafferentation has minimal morphological effects on the carotid body. The reactions of other receptor cells to deafferentation are compared with those of the glomus cells.

Animals↗
PubMed1976

The effects of 6-hydroxydopamine on the appearance of granulated vesicles in glomus cells of the rat carotid body.

The glomus cells of the rat carotid body reveal an intense fluorescence after exposure to paraformaldehyde vapor and contain catecholamines. After initial fixation in glutaraldehyde, many granulated vesicles are seen in the glomus cells. After initial fixation in osmium tetroxide, most of the vesicles are depleted of their dense interiors and granulated vesicles occur infrequently. Administration of 6-hydroxydopamine followed by initial fixation in osmium tetroxide leads to the reapperance of dense interiors in virtually all vesicles. 6-Hydroxydopamine apparently is taken up by the membrane pump of the glomus cell and is incorporated into the amine storage granules, thereby displacing the endogenous monoamines. Osmium tetroxide does not dissolve the 6-hydroxydopamine from the vesicles, as it apparently does for the normal vesicular contents. The 6-hydroxydopamine does not fluoresce, hence 6-hydroxydopamine administration results in a decreased intensity of formaldehyde induced fluorescence in the glomus cells. Administration of reserpine after 6-hydroxydopamine treatment (and subsequent initial fixation in osmium tetroxide) depletes the previously restored dense material from the vesicles of the glomus cells. 6-Hydroxydopamine acts like a monoamine in that it is taken up by the glomus cell, incorporated into the vesicles, and can be depleted from the vesicles by reserpine.

Animals↗