Gastrointestinal and in vitro release of copper, cadmium, indium, mercury and zinc from conventional and copper-rich amalgams

Abstract – Particles of a conventional lathe-cut, a spherical non-gamma 2 and a copper amalgam have been gastrointestinally administered to rats for the purpose of evaluation of the dissolution resistance. The animals were sacrificed after 20 hrs. The contents of copper, cadmium, indium, mercury and zinc in kidney, liver, lung or blood were measured using nuclear tracer techniques. From a copper amalgam an extreme release of copper was demonstrated. This study simulates the clinical condition of elemental release from swallowed amalgam particles after amalgam insertion or after removal of old amalgam fillings. Specimens of the same types of amalgams were also exposed to artificial saliva for a period of 10 days. The amounts of copper and mercury released were measured with flame and flameless atomic absorption spectrophotometry respectively. The levels of copper and mercury released from the copper amalgam were approximately 50 times those of the two other amalgam types studied.     

Immune function during ageing in man: relation between serological abnormalities and cellular immune status

In a group of 176 apparently healthy aged people living at home (age range 62-86 years) the prevalences of monoclonal immunoglobulin and of autoantibodies did not differ from those found in other studies, but remarkably 38% of the people studied had cold lymphocytotoxic antibodies. The occurrence of serological abnormalities showed no age dependency. The participants were grouped according to serological abnormalities. The various groups showed no differences in peripheral blood mononuclear cell composition (concentration of B lymphocytes and T lymphocytes or of T lymphocyte subsets with OKT 4 and OKT 8 phenotype) or function (lymphocyte stimulation with phytohaemagglutinin, concanavalin A, pokeweed mitogen and antigen cocktail). Compared with a control group of young blood donors, the lymphocyte stimulation responses tended to be lower in the old age groups. It is concluded that, as measured in this study, humoral abnormalities during ageing are not associated with changes in B and T lymphocyte subsets or function.     

Changes in high affinity choline uptake in rat cortex following lesions of the magnocellular forebrain nuclei

High affinity choline uptake (HACU) and choline acetyltransferase (CAT) were measured in the cerebral cortex of rats 4 and 20 days after placing electrolytic lesions in the magnocellular forebrain nuclei (MFN) or in the pallidum.Four days after MFN lesion a 40–50% decrease in ipsilateral cortical HACU was found and a slightly smaller decrease was found 4 days after the pallidum lesion. Twenty days after the lesion, HACU activity returned to control values in the ipsilateral parietal cortex, its decrease was smaller than 4 days postlesion in the ipsilateral frontal cortex and a significant increase was found in the contralateral cortex.CAT activity showed a 40% decrease in the frontal, parietal and occipital ipsilateral cortex 4 days after MFN lesion. The same decrease was found 20 days postlesion. However, at this time a significant increase in CAT activity was detected in the contralateral cortex.The ipsilateral recovery of HACU activity 20 days after the lesions and the contralateral increase in HACU and CAT activity demonstrate the remarkable and widespread functional adjustment associated with discrete brain lesions. The existence of a large cholinergic pathway projecting to the neocortex from the basal forebrain region is also confirmed.     

(Z)-Dimethylamino-l-(4-bromophenyl)-l-(3-pyridyl) propene (H 102/09), a New Selective Inhibitor of the Neuronal 5-Hydroxytryptamine Uptake

Abstract The inhibition of the uptake of ³H–(–)–noradrenaline (NA), ³H–dopamine and ¹⁴C–5–hydroxytryptamine (5–HT) in mouse brain slices by (Z)–3–dimethylamino–l–(4–bromophenyl)–l–(3–pyridyl)propene (H 102/09), desipramine and chlorimipramine and their releasing effect on the ³H–amines previously accumulated in the slices were examined. The interactions with reserpine produced hypothermia and sedation and the 5–hydroxytryptophan (5–HTP) syndrome in mice were also studied. Due to the poor inhibitory activity on the NA uptake H 102/09 was a more selective inhibitor of the 5–HT uptake than was chlorimipramine, particularly after administration in vivo, where it was as potent as chlorimipramine (ED50 = 19 μmol/kg intraperitoneally). In vitro chlorimipramine was 6 to 12 times more active than H 102/09. Desipramine was a very selective inhibitor of the NA uptake in vitro and in vivo. The compounds were generally more potent in inhibiting the uptake than in releasing the amines. However, in striatal slices the inhibition of DA uptake could be due to the releasing effect since the difference in potencies were small. The effect of desipramine on 5–HT uptake and that of H 102/09 on NA uptake could also involve a release component. The 5–HTP syndrome was potentiated by H 102/09 and chlorimipramine but not by desipramine. The reserpine hypothermia but not the sedation was potently antagonized and reversed by desipramine and by chlorimipramine at high doses but not by H 102/09, suggesting that NA but not 5–HT is involved in the hypothermic action of reserpine.     

Effect of Hypophysectomy and Adrenalectomy on 5-Hydroxytryptamine Uptake by Rat Hypothalamic Synaptosomes and Blood Platelets

Abstract: The effect of adrenalectomy and hypophysectomy on 5-HT uptake by rat platelets and hypothalamic synaptosomes taken from the same animal was studied. The experiments were performed 1–2 weeks after the operations or the shamoperations. After adrenalectomy a significant decrease of 25% in 5-HT uptake by platelets was noted. In synaptosomes there was a similar trend, but the decrease was not significant. After hypophysectomy a significant 25% decrease in 5-HT uptake was observed both in platelets and in synaptosomes. These results suggest that corticosteroid hormones might mediate adaptive changes of 5-HT uptake both in synaptosomes and in blood platelets. Blood platelets have been used as a peripheral model of serotoninergic nerve terminal in studies concerning physiology of monoamines systems, but the present results suggest that also in some pathological conditions changes in platelet biochemistry could reflect those in the CNS neurones.     

Selectivity of the uptake of glutamate and GABA in two morphologically distinct insect neuromuscular synapses

The common inhibitor (CI) and slow excitor tibiae (SETi) innervated slow muscles 135cd of the locust Schistocerca gregaria were incubated under high-affinity uptake conditions either in [3H]GABA or in [3H]glutamate. [3H]GABA is accumulated in the glia of the nerve endings of the CI as well as the SETi; however, it is accumulated only in the terminal axons of the CI, not in the terminal axons of the SETi. The grain densities above the glia and above the CI terminal axons are approximately 2 grains/micron2. After incubation in [3H]glutamate the grain densities above the CI terminal axons and the SETi terminal axons are approximately 4 grains/micron2; the grain densities above the glia of both types of nerve endings are approximately 17 grains/micron2. The relatively high labeling (3 grains/micron2) of the muscles after incubation in the presence of glutamate is ascribed to the high metabolic requirements of slow muscles. The conclusion is drawn that a high-affinity uptake system for GABA is present in the CI terminal axons and in the glia of both the CI and SETi nerve endings. However, while the glutamate uptake in the CI and SETi nerve endings of the slow 135cd is comparable to the high-affinity uptake of glutamate in the fast excitor tibiae (FETi) nerve endings of the fast retractor unguis muscle, a high-affinity uptake of glutamate was only demonstrated in the glia of both types of nerve endings. A high-affinity uptake in the terminal axons of the CI and SETi may be masked by an extensively low-affinity uptake of glutamate by the muscles.     

Marrow Cell Uptake by Megakaryocytes in Routine Bone Marrow Smears during Blood Loss

In studying smears of marrow aspirates, we have encountered the presence of normal appearing haemopoietic cells within megakaryocytes. We have then searched routine marrow smears from 125 patients seen in our service during 3 years. The presence of marrow cells (granulocytic, erythroid, and lymphoid cells) within megakaryocytes was seen in 16 cases of whom 9 had documented bleeding and 5 had carcinoma. 3 patients were suspected of bleeding but this was not documented. 56 % of patients with bleeding and 83 % of patients with carcinoma seen during this period displayed this phenomenon. A search for this phenomenon in routine marrow smears may reveal unsuspected blood loss.     

间硝苯吡啶与硝苯吡啶对左室功能及心肌氧耗的比较研究

间硝苯吡啶(M-Nif)为新合成的钙拮抗剂。实验表明,M-Nif可增加麻醉狗的CI、SI,降低麻醉猫的舒张压、TTI较Nif强而持久。Nif增加心率,M-Nif却无影响或略减少。M-Nif增加冠状窦氧含量,缩小动静脉氧差的强度弱于Nif,但降低心肌氧摄取率。二氧化碳产生率则较Nif强。提示M-Nif治疗充血性心力衰竭优于Nif。     

Fertilitätsreduktion durch zelluläre Immunreaktion gegen Spermatozoen-Antigene*

Im syngenen und allogenen System wurde tierexperimentell versucht, den Einfluß spermasensibilisierter Lymphozyten als Ausdruck einer zellulären Sensibilisierung ge-gen Spermatozoen auf die Fruchtbarkeitsrate von Mäusen zu beziehen. Mit großer Wahrscheinlichkeit ist anzunehmen, daß eine durch Milzzellenübertragung hervorgeru-fene Immunreaktion im Sinne einer Fertilitätsreduktion hauptsächlich durch T-Lym-phozyten bedingt ist. Nach Immunisierung der Stämme C₅₇bl₆ und C₃H mit Spermatozoen des Inzuchtmäusestammes C₅₇bl₆ war in jedem Fall eine signifikante Dicken-zunahme der Pfoten als Ausdruck des Sensibilisierungsgrades im zellulären Immunsy-stem zu beobachten. Dagegen ergab der Test nach Immunisierung mit Spermatozoen des Stammes C₃H im Vergleich zu den Kontrolltieren keine signifikante Pfoten-Dik-kenzunahme. Nach Transfer der gefilterten Milzzellen von jeweils 2 immunisierten Weibchen auf eine virginelle weibliche Maus zeigte der Footpadmeter-Test kurz vor der Befruchtung eine statistisch signifikante Dickenzunahme der Pfoten nur bei Weibchen des Stammes C₃H, denen syngene Milzzellen von Mäusen injiziert war, die man mit Spermatozoen des Stammes C₅₇bl₆ immunisiert hatte. Bei den anderen Gruppen erga-ben sich im Vergleich zu den Kontrolltieren keine signifikanten Unterschiede. Eine signifikante Fertilitäts-Reduktion ergab sich in übereinstimmung mit der nachgewiesenen Sensibilisierung auch lediglich bei allogen mit Spermatozoen des Stammes C₅₇bl₆ sen-sibilisiert und befruchteten Weibchen des Stammes C₃H. Sowohl bei Mäusen des Stammes C₃H als auch C₅₇b₁₆, denen Zellen syngen immunisierter Weibchen übertragen wa-ren, ergab sich keine statistisch signifikante Fruchtbarkeitsminderung. Insgesamt scheint eine zelluläre Immunreaktion gegen Spermatozoen die Befruchtungsrate weni-ger zu beeinflussen als die übertragung von agglutinierenden und immobilisierenden Spermaantikörpern. Parallel zum im Versuch beschriebenen Milzzelltransfer spermasensibilisierter Mäuse ergab der Serumtransfer eine statistisch signifikante Fertilitätsre-duktion bei beiden Inzuchtstämmen nach Sensibilisierung mit C₅₇bl₆ Spermatozoen, also im syngenen und allogenen System. Diese an Inzuchtmäusen gewonnenen Ergeb-nisse weisen darauf hin, daß immunologisch bedingte Sterilitäten nicht nur auf humo-nalen, sondern auch auf zellulären Immunreaktionen beruhen können.     

Effect of coupling the breathing- and cycling rhythms on oxygen uptake during bicycle ergometry

Summary The influence of the degree of coupling between the breathing and cycling rhythms (K) on oxygen uptake was examined in 30 volunteers. They cycled on an ergometer with a load equal to 50% of their work capacity 170 in two experimental runs with spontaneous breathing rhythm, and in a further two runs with acoustically triggered breathing. K was continuously ascertained. and other respiratory parameters were measured by an automatic breath-by-breath analysis system.In 16 subjects, -differences between runs were correlated with the differences in K. In the majority of these subjects (12), decreased significantly with increasing K. In 14 subjects, -and K-variations within individual runs were analyzed. Phases with higher K were regularly accompanied by a decrease in .It is concluded that coupling the breathing and cycling rhythms reduces for a given moderate work load, although the magnitude of the -reduction varies considerably between individuals.