Induction of monocyte chemotaxis in devascularized rabbit bone

Summary Temporary impairment of blood supply has been suggested to cause bone remodeling. The degradation of cells and matrix and the attraction of resorbing cells were examined in this study. Bone specimens of rabbits were stored in vitro for 2–20 days. At the end of this aging process the probes were tested for their chemotactic activity toward autologous leukocytes in a diffusion chamber. Both supernatant from the aged bone specimens and ground bone particles exhibited significant chemotactic activity that was specifically attracting monocytes. It is suggested that soluble bone matrix proteins or degeneration products liberated during ischemic damage to cortical bone initiate the resorptive process.This work was supported by the Swiss National Science Foundation, grant no. 3.857.0.83, and by the Studienstiftung des deutschen Volkes     

Work at sea: a study of sleep,and of circadian rhythms in physiological and psychological functions,in watchkeepers on merchant vessels

Summary Sleep length and sleep quality scores were collected on board ships over periods of up to two weeks from 38 watchkeepers working a 4-on/8-off routine and 29 dayworkers. All watchkeepers exhibited fragmented sleeping patterns, which indicated a lack of adaptation of the sleep/wakefulness cycle to the hours of work. There were only slight differences in total sleep length between watchkeepers and dayworkers, however, both groups did not obtain an adequate amount of sleep. Within the watchkeeping crews the 3rd Officers had by far the shortest sleep length. Concerning sleep quality, daytime sleep was generally given the lowest ratings, whereas sleep starting before midnight was on average evaluated as the best, both by watchkeepers and dayworkers. Watchkeeping personnel do not normally have any days off during a voyage so that missed sleep might even amount to a sleep deficit. A solution for this problem could perhaps be a new, stabilized system that allows a single uninterrupted sleep, which is required for full recuperation, to be taken each day.Dedicated to Professor J. Aschoff on the occasion of his 75th birthdayPartly supported by a grant from the Ministry for Technology and Research, Federal Republic of Germany, Project Schiff der Zukunft, Part ET83b     

Production of mouse mammary tumor virus upon transfection of a recombinant proviral DNA into cultured cells

We have investigated the intracellular proteins synthesized in rat XC and feline kidney cells transfected with endogenous mouse mammary tumor virus (MMTV) proviral DNA. The endogenous provirus GR40, associated with the Mtv-8 locus, directs the synthesis of gag proteins indistinguishable from those found in MMTV-infected cells. The env precursor Pr73env and the mature gp52 proteins could not be detected in these cells. Instead an env-related protein of 68K is synthesized. In contrast to this endogenous provirus, a cloned exogenous proviral variant directs the synthesis of apparently normal env proteins upon transfection into the same cell lines. These results suggest that the env gene of the endogenous MMTV provirus GR40 is defective. The exogenous proviral variant is not expected to synthesize virus particles since it carries a rearrangement in the gag gene. In order to obtain an MMTV provirus capable of correctly expressing both gag and env functions, we have constructed a hybrid endogenous-exogenous provirus containing the 5' long terminal repeat (LTR)-gag of GR40 and the pol-env-3' LTR of the exogenous provirus. Upon transfection into feline kidney cells, this hybrid provirus directed the synthesis of apparently authentic gag and env proteins. Further, virus particles can be detected in the culture medium of the transfected cells by electron microscopy. Viral proteins obtained from viral particles banded in a sucrose gradient were detected by immunoprecipitation.     

Knochenheilung und dynamischer Interferenzstrom (DIC). —Erste vergleichende tierexperimentelle Studie an Schafen Teil II: Physikalische und chemische Ergebnisse

Zusammenfassung Zusätzlich wurden physikalische und chemische Untersuchungen über den Einfluß von dynamischem Interferenzstrom (DIC) auf die Knochenheilung durchgeführt, nachdem bei 24 Schwarzkopfschafen eine Querosteotomie des Radius vorgenommen worden war. Nach instabiler Osteosynthese wurde die Osteotomiezone wiederholt mit DIC verschiedener mA—Stärken behandelt. (Methodische Einzelheiten sind in Teil I beschrieben). Die Behandlung mit dynamischem Interferenzstrom führte im behandelten Gewebe zu steigenden Temperaturen, die von den mA—Stärken abhängig waren. Weiterhin wurden Zusammenhänge zwischen DIC—mA—Intensität und dem Vorkommen von Hydroxyprolin, einer kollagenspezifischen Aminosäure, nachgewiesen, welches eine erhöhte Calcifizierungsaktivität zur Folge hatte. Messungen des Calcium— und Phosphorgehaltes im neugebildeten Knochengewebe wiesen bei den mit DIC behandelten Tieren vollständige Mineralisation zu einem viel früheren Zeitpunkt als bei den unbehandelten, nach gleichem Verfahren operierten Kontrolltieren auf. Ob DIC einen spezifischen Reiz auf die Knochenneubildung heilender Knochen ausübt, ist noch nicht vollständig geklärt.

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Bone healing and Dynamic Interferential Current (DIC)

Summary In the course of supplementary physical and chemical investigations of the influence ofDynamicInterferential Current (DIC) on bone healing 24 black-head sheep were subjected to transversal osteotomy of the radius. After an instable osteosynthesis the site was exposed to repeated therapy with DIC of varying mA intensity. (Methodological details are described in part 1.) DIC therapy resulted in altering the temperatures in the treated tissue, dependent on the mA intensity. Further associations were verified between DIC intensity and the occurrence of hydroxyprolin, an amino acid specific collagen, which also reflected increased calcifying activity. Measurements of the calcium and phosphorus levels in the regenerated (newly forming) bone tissue documented full mineralization in the DIC-treated animals at a much earlier date than in the untreated controls that had undergone similar operations. Whether DIC specifically stimulates osteogenesis within healing bones is still unclear.

     

Biochemical Binding and Distribution of Protactinium-233 in the Rat

Summary

Following intravenous injection into male Sprague–Dawley rats ²³³Pa, like other elements, deposits predominantly in the skeleton (ca. 70–80 per cent), but unlike Pu and Am the liver deposition of ²³³Pa is low, about 2–3 per cent between 1 and 7 days. About 99 per cent of the injected ²³³Pa is lost from the plasma compartment in 3 days, a clearance comparable to that of Pu but much slower than that of Np, Am or Cm. On entering the liver cell cytosol ²³³Pa is bound rapidly to an unidentified protein of molecular mass 200 kDa and to a protein of 80 kDa, which is probably transferrin. Within a few hours the metal migrates to bind to a protein of > 400 kDa which has been tentatively identified as ferritin. Some ²³³Pa remains bound to small ligands until virtually all the intracellular ²³³Pa has been deposited in the lysosomes, or to a lesser extent in some other, as yet, unidentified organelles.     

199. Die Oberarmschaftfraktur beim Schwerverletzten: Eine Indikation zur Osteosynthese?

Zusammenfassung Die hohe metaphysare Tibiafraktur im Kindesalter ist selten. Bei einem Teil der Frakturen stellt sich trotz nahezu achsengerechter Einstellung ein Valgusfehlwachstum ein. Dies ist mehrfach beschrieben, fiber die Ursache gibt es verschiedene Theorien. Neben anderen wird uber ein 17 Monate altes Mädchen berichtet, bei dem eine Korrekturosteotomie durchgeführt werden mußte. Die Möglichkeiten zur Verhinderung and zur Behandlung werden diskutiert.     

The effect of mercuric chloride on the excretion of two urinary enzymes in the rat

The effect of intravenous injections of HgCl₂ on the renal excretion of alkaline phosphatase (AP) and leucine aminopeptidase (LAP) was investigated in rats. On the first day after Hg enzyme excretion showed a linear rise with the Hg dose from a threshold value of 0.44 mg Hg/kg. On the second day a statistically significant effect was seen already after 0.25 mg Hg/kg. After doses of 0.75 mg/kg or more a decrease of enzyme activity below control values occurred which persisted for more than 4 days.Treatment with 2,3-dimercaptopropansulfonate (DMPS) brought about a normalization of AP excretion. An effect on LAP excretion was observed only with early treatment. The same holds for the effect of DMPS on Hg-induced lethality.The usefulness of a measurement of LAP excretion for estimating the exposure to inorganic mercury is discussed.

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Zusammenfassung Die Wirkung von intravenös verabreichtem HgCl₂ auf die renale Ausscheidung von alkalischer Phosphatase (AP) und Leucinaminopeptidase (LAP) wurde an Ratten untersucht. Am ersten Tag nach Hg-Injektion erfolgte ein Anstieg der Enzymausscheidung, der von einem Schwellenwert von 0.44 mg Hg/kg ausgehend eine lineare Abhängigkeit von der Hg-Dosis aufwies. Am zweiten Tag wurde ein statistisch signifikanter Effekt bereits nach 0.25 mg Hg/kg beobachtet. Nach Dosen von 0.75 mg Hg/kg oder mehr fand ein Abfall der Enzymaktivität unter die Kontrollwerte statt, der mehr als 4 Tage anhielt.Behandlung mit 2,3-Dimercaptopropansulfonat (DMPS) bewirkte eine Normalisierung der AP-Ausscheidung. Eine Wirkung auf die LAP-Exkretion wurde nur bei baldiger Verabreichung von DMPS beobachtet. Das gleiche gilt für den Effekt von DMPS auf die Hg-induzierte Letalität.Die Nützlichkeit einer LAP-Bestimmung im Urin zur Abschätzung einer Hg-Inkorporation wird diskutiert.

     

Different muscarine receptors mediate the prejunctional inhibition of [3H]-noradrenaline release in rat or guinea-pig iris and the contraction of the rabbit iris sphincter muscle

Summary To investigate the muscarine receptor type mediating inhibition of [³H]-noradrenaline release from the isolated rat and guinea-pig iris we have determined the potency of antimuscarinic drugs to antagonize the methacholine-induced inhibition of [³H]-noradrenaline overflow evoked by field stimulation (3 Hz, 2 min). The prejunctional apparent affinities were compared with those obtained for postjunctional muscarine receptors mediating the methacholine-induced contraction of the isolated rabbit iris sphincter muscle.Prejunctional apparent affinity constants of pirenzepine (6.67), himbacine (8.51), methoctramine (7.92), 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP, 8.00), hexahydro-difenidol enantiomers (6.92, (R); 5.77, (S)) in the rat iris and methoctramine (7.58) in the guinea-pig iris indicate the presence of M₂ receptors. Although the post-junctional affinity constants in the rabbit iris sphincter of methoctramine (5.93), gallamine (3.92), and 4-DAMP (9.07) confirm our previous suggestions of the presence of M₃-like receptors, the results obtained with the hexahydro-difenidol enantiomers do not agree with that concept. The post-junctional affinity constants of the hexahydro-difenidol enantiomers were not different from the prejunctional values (6.86, (R); 5.55, (S)), indicating a similar and low degree of stereoselectivity for these stereoisomers at both receptor sites (14 and 17, (R)/(S)-ratios, respectively). Hence, the postjunctional muscarine receptor in the rabbit iris sphincter fails to exhibit the high degree of stereo selectivity observed for hexahydro-difenidol enantiomers at M₃ receptors on other smooth muscles.This study was supported by the Deusche Forschungsgemeinschaft (Fu 163/2) Send offprint requests to H. Fuder at the above address     

喹胺酸和LICAM(C)对大鼠体内238Pu和241Am的促排效果比较

喹胺酸(Quinamic acid, QAA, 811)是一种异哇啉类络合剂, 对钍有较好的促排效果。本文主要研究大鼠静脉注入(iv)²³⁸Pu和²⁴¹Am各26kBq/kg后1小时, 经皮下注入(so)不同剂量.(1～30μmol/kg)QAA, 或静脉注入核素后立即灌胃(po)QAA(30μmol/kg)对²³⁸Pu、²⁴¹Am的促排疗效, 并与LICAM(C)相比较。实验观察到QAA对降低骨肝中²³⁸Pu、²⁴¹Am的蓄积量有较好的作用, QAA对²³⁸Pu的促排效果高于对²⁴¹Am.在剂量(1～30μgmol/kg)对肝、肾中²³⁸Pu和骨、肾中²⁴¹Am蓄积量的降低, QAA优于LICAM(C)；灌胃QAA(30μttmol/kg)伍用NaHCO₃(5mmol/kg的)疗效, 对骨、肝中²³⁸Pu蓄积量的降低, QAA和LICAM(C)二间无差异(P>0.05), 但对²³⁸Pu在肾中蓄积量和对²⁴¹Am在骨, 肾中蓄积量的降低, QAA明显优于LICAM(C)。