Susceptibility to beta-lactam antibiotics in septicemia isolates from twenty-nine European laboratories

In 1984 the European Study Group on Antibiotic Resistance (ESGAR) consecutively collected gram-negative bacilli and staphylococci blood isolates and performed susceptibility testing with 11 antibiotics using the microdilution method. In all 2,578 isolates were collected: 68% gram-negative bacilli and 32% staphylococci. The MICs of ampicillin and cefazoline for the susceptible gram-negative bacilli were 1–8g/ml; of piperacillin0.5–4; of Sch 34343, cefotaxime, moxalactam, ceftazidime and aztreonam0.5–2g/ml; of cefoxitin, cefuroxime and cefamandole0.5–8g/ml. For susceptible staphylococci the MICs of cefazoline and cefuroxime were0.5–1g/ml, and of cefoxitin, moxalactam, ceftazidime and cefotaxime,0.5–32 g/ml. The resistance levels varied between laboratories and countries, being lower in Northern Europe. In clinical protocols on patients with gram-negative septicemia from whom cefazoline-resistant strains were isolated, cefotaxime was the beta-lactam most commonly used (12%). In protocols on patients with staphylococcal septicemia from whom gentamicin-resistant or cefazoline-resistant strains were isolated, the most commonly used beta-lactam was cloxacillin (6%).     

Modulation of Nav1.5 by β1- and β3-subunit co-expression in mammalian cells

Cardiac sodium channels (Na_v1.5) comprise a pore-forming -subunit and auxiliary -subunits that modulate channel function. In the heart, 1 is expressed throughout the atria and ventricles, whilst 3 is present only in the ventricles and Purkinje fibers. In view of this expression pattern, we determined the effects of 3 and 1 co-expression alone, and in combination, on Na_v1.5 stably expressed in Chinese hamster ovary cells. The current/voltage relationship was shifted –5 mV with either 1 or 3 co-expression alone and –10 mV with co-expression of both 1 and 3. In addition, 3 and 1/3 co-expression accelerated macroscopic current decay. There were significant hyperpolarizing shifts in equilibrium gating relationships with co-expression of 1 and 3 alone and in combination. Co-expression of 1/3 together resulted in a greater hyperpolarizing shift in channel availability, and an increase in the slopes of equilibrium gating relationships. Co-expression of 3 and 1/3, but not 1, slowed recovery from inactivation at –90 mV. Development of inactivation at –70 and –50 mV was accelerated by -subunit co-expression alone and in combination. -Subunit co-expression also reduced the late Na current measured at 200 ms. In conclusion, -subunits modulate Na_v1.5 gating with important differences between co-expression of 1 and 3 alone and 1/3 together.     

Scanning electron microscopy of merogonous stages ofEimeria falciformis var.pragensis inMus musculus

Asexual stages ofEimeria falciformis var.pragensis in Swiss-Webster mice were studied by scanning electron microscopy. Sporozoites were present in the cecum and colon 2 h post-inoculation (PI) and measured 11.3×2.1 m (9–13.9×2–2.2 m). Sporozoites penetrated epithelial cells with an extended anterior end and were constricted at the site of entry. Asexual generations were found in the cecum and colon epithelial cells. In meronts found at days 3–6 PI, merozoites matured synchronously, were oriented in the same direction, and were arranged in a helical pattern. Such meronts measured 11.3×6.4 m (8–13.7×5–7.4 m) and contained 8–12 meroxoites, which measured 11.9×1.5 m (7.4–15.7×1.3–1.8 m). Meronts which were present at day 7 PI measured 9.5×8.2 m (9–10.5×7–9.5 m) and contained 20–50 small merozoites which budded asynchronously from a central residuum. At days 3–7 PI, parasitized epithelial cells had shorter and fewer or no microvilli. The lumenal plasmalemma of the host cell was often disrupted or absent in cells containing mature meronts and escaping merozoites. At day 6 PI, phagocytic cells appeared on the epithelial surface, some of which were in contact with merozoites. Small foci of exposed basal lamina were present at day 7 PI in areas where cells had sloughed from the epithelium.     

A monovalent ion-selective cation current activated by noradrenaline in smooth muscle cells of rabbit ear artery

We have studied chloride influx and efflux in a highly purified preparation of type n cells freshly isolated from adult guinea-pig lung using ³⁶Cl^–. Chloride uptake was time-dependent, saturable (K_m<10 mM) and was inhibited by 4,4-diisothiocyanatostilbene-2,2-disulphonic acid (DIDS; K_i80 M). In the absence of external chloride (substituted by gluconate), ³⁶Cl^– uptake exhibited an overshoot above equilibrium. The rate of ³⁶Cl^– entry was strongly inhibited by addition of external nitrate; sulphate was a weaker inhibitor. ³⁶Cl^– efflux was stimulated by external bromide > bicarbonate chloride citrate; and was inhibited by proprionate > acetate > oxalate. Although the chloride channel blocker 4-nitro-2-(3-phenylpropylamino)benzoate (0.14 mM) caused an inhibition, ³⁶Cl^– influx did not appear to be electrogenic. These data are compatible with the existence of a substantial electroneutral anionexchange pathway for chloride transport in freshly isolated adult type II pneumocytes.     

Summation and adaptation in stimulation of the motor cortex in adult and newborn animals

Summary In rabbits and their progeny an investigation was made of summation and adaptation of the neurones of the motor cortex; unipolar stimulation was used, and the muscular response recorded. Two types of summation curves were found: exponential and Y-shaped,, and were related to the direct and indirect summation of stimulation. In adults, Y-shaped summation curves were more frequent, whereas in rabbits aged 24 h exponential curves preponderted. We found very little capacity for adaptation at any age.(Presented by Active Member AMN SSSR A. F. Turom) Translated from Byulleten Éksperimental'noi Biologii i Medisiny, Vol. 55, No. 6, pp. 3–7, June, 1963     

Vasopressin studies in the rat

Summary In previous experiments single i.v. injections of 0.2–10 U ADH were made in alcohol anesthetized rats and the amount of extra water reabsorbed during the antidiuretic phase (urine deficit) was measured. The dose response curve resembled a saturation curve with a fairly linear rise up to 1–1.5 U. When 4–6 U were injected the urine deficit was not appreciably greater while 75% of the ADH injected appeared in the urine during antidiuresis. It was concluded that during a single injection of ADH 1–1.5 U were bound almost instantaneously at receptors of the tubular wall and inactivated during the slow process of water reabsorption, while the excess ADH was excreted in the urine. It was estimated that 1 U ADH was needed for the reabsorption of approximately 5 cm³ water. The time required for this process is short at a high rate of reabsorption and vice versa.In the present investigation the single i.v. injections were repeated with 20 U. The higher dose permitted the separate determination of ADA in 3 consecutive samples of the urine collected during the antidiuretic phase. The result fully confirmed the working hypothesis e.g.:1. The antidiuretic activity (ADA) obtained with 20 U Pitressin was not greater but even (though not significantly) smaller than that obtained previously with 5 U Pitressin or 1 U Tonephin.2. 95±15% of the ADA injected appeared in the urine. This means that the difference between the 20 U injected and the 18.5–19 U appearing in the urine after deduction of the 1–1.5 U ADH supposedly bound at tubular pore sites was too small to be detected with our bioassay.3. Under the assumption that 1 U Pitressin was used up for the reabsorption of approximately 4 cm³ water a vasopressin-water-equivalent in the order of 1 mole vasopressin for 10⁸ mole water reabsorbed, could be calculated.4. The amount of vasopressin excreted by the kidney follows an exponential function with a half life of 5 min.5. The vasopressin clearance is approximately 1.0 cm³/min · rat and lies within the range of inulin clearance (1.2 cm³/min · rat). It is suggested that elimination of excess vasopressin proceeds by a simple filtration process.6. Calculating on a weight basis the ADH-requirement of the 200 times heavier human kidneys leads to the value 200–300 U. Using a vasopressin-water-equivalent of 4–5 cm³ water per 1–1.5 U (action time 50 min) it can be predicted that the human kidney must lose approximately 261 water per day under the condition of a complete lack of vasopressin. This agreement with the actual observations in diabetes insipidus patients supports the belief that some of the concepts worked out in the alcohol anesthetized rat are valid under circumstances other than the strict conditions of this preparation.

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Zusammenfassung In früheren Experimenten wurden Einzelinjektionen von 0,2–10 E ADH in Alkohol narkotisierte Ratten gemacht und die Wassermenge bestimmt, die während der antidiuretischen Phase rückresorbiert wurde. Die Dosis-Antwort-Kurve hatte den Charakter einer Sättigungskurve mit einem praktisch linearen Anstieg bis 1–1,5 E. Der antidiuretische Effekt war bei einer Injektion von 4–6 E nicht deutlich größer als bei der kleineren Dosis, gleichzeitig fanden sich 75% der injizierten ADH-Menge im Urin der antidiuretischen Phase. Es wurde geschlossen, daß während einer Einzelinjektion von ADH 1–1,5 E fast augenblicklich von Receptoren der Tubuluswand gebunden und dann während des langssamen Prozesses der Wasserresorption inaktiviert werden, während das überschüssige ADH im Urin ausgeschieden wird. Schätzungsweise war 1 E ADH erforderlich, um 5 cm³ Wasser rückzuresorbieren. Die für den Resorptionsvorgang erforderliche Zeit war relativ kurz bei hoher Resorptionsrate und umgekehrt.In den vorliegenden Untersuchungen wurden die Einzelinjektionen mit 20 E wiederholt. Die höhere Dosis erlaubte, die antidiuretische Aktivität (ADA) in drei aufeinanderfolgenden Urinportionen der antidiuretischen Phase getrennt zu bestimmen. Das Resultat bestätigte die Arbeitshypothese.1. Die mit 20 E Pitressin erzielte ADA von 4 cm³ war nicht größer, sondern (nicht signifikant) kleiner als diejenige, die in den früheren Versuchen mit 5 E Pitressin oder 1 E Tonephin gefunden wurden.2. 95±15% der injizierten ADA erschienen im Urin. Das heißt, die Differenz zwischen den 20 injizierten E und den 18,5–19 E, die nach Abzug der vermutlich an der Tubuluswand gebundenen 1–1,5 E ausgeschieden wurden, war zu klein, um mit unserem Bioassay entdeckt zu werden.3. Unter der Annahme, daß 1 E Pitressin verbraucht wurde für die Resorption von ungefähr 4 cm³ Wasser, kann ein Vasopressin-Wasser-Äquivalent von ungefähr 1 Mol Vasopressin für 10⁸ Mol Wasser errechnet werden.4. Die durch die Niere ausgeschiedene Vasopressin-Menge folgt einer e-Funktion mit einer Halbwertszeit von 5 min.5. Die Vasopressin-Clearance beträgt ungefähr 1,0 cm³/min · Ratte und liegt somit wenig unter der Inulin-Clearance (1,2 cm³/min · Ratte). Diese Tatsache legt die Vermutung nahe, daß das überschüssige Vasopressin durch einfache Filtration ausgeschieden wird.6. Wenn man unter Berücksichtigung der unterschiedlichen Nierengewichte den ADH-Bedarf der 200mal schwereren Menschenniere schätzt, so kommt man auf 200–300 E. Setzt man ein Vasopressin-Wasser-Äquivalent von 4–5 cm³ pro 1–1,5 E ADH bei einer Wirkzeit von 50 min in Rechnung, so sollte die menschliche Niere ca. 261 Wasser pro Tag bei völligem Fehlen von ADH verlieren. Die Übereinstimmung mit dem wirklichen Wert könnte dafür sprechen, daß ein Teil der Resultate, die an der Alkohol-narkotisierten Ratte gewonnen wurden, nicht nur unter den strikten Bedingungen dieses Präparates gelten.

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This work was supported by Contract AF 61 (052)-947 of the USAF School of Aerospace Medicine, European Office of Aerospace Research (OAR), U.S. Air Force and the Deutsche Forschungsgemeinschaft.     

Ribonucleic acids of Machupo and Lassa viruses

Summary Sucrose gradient velocity centrifugation, polyacrylamide gel electrophoresis and RNA-RNA hybridization were used to characterize Lassa and Machupo virion RNAs as well as virus-specific RNAs from cells infected with Pichinde and Machupo viruses. Five RNA species: 30–31S, 28S, 22–24S, 18S and 4–6S have been detected in Lassa, Machupo, and Pichinde virion RNAs. Among them 28S, 18S and 4–6S RNAs cosediment and comigrate with respectivelv cell RNAs. RNase resistance analyses suggest the presence of extensive secondary structures and complementary RNAs in Lassa, Machupo, and Pichinde virion RNAs. Annealing with poly(A)-containing RNA from infected cells has revealed that the bulk of minus strands of Machupo virion RNA is located in 22–24S and 28–31S fractions of sucrose gradient. Thus Machupo and Lassa viruses as well as Pichinde virus contain two genomic RNA fragments: large (molecular weight of about 2.2 × 10⁶) and small (molecular weight of about 1.3 × 10⁶).In the cells infected with Pichinde virus and treated with actinomycin D (1.0 µg/ml) synthesis of 18S,22–24S and 30–31S RNAs has been registered. At least 22–24S and 30–31S classes comprise plus and minus strands. In cells infected with Machupo virus in the presence of actinomycin D the synthesis of similar sedimentation classes of RNAs and certain amounts of 28S RNA have been detected.With 4 Figures     

Criteria for testing the susceptibility ofStreptococcus pneumoniae to cefotaxime and its desacetyl metabolite using 1 μg or 30 μg cefotaxime disks

In vitro susceptibility tests were performed with 350 selected strains ofStreptococcus pneumoniae to evaluate disk diffusion tests with 30 g and 1 g cefotaxime disks. Zones were compared to MICs of cefotaxime with and without its desacetyl metabolite. Cefotaxime was two to eight times more active than desacetyl cefotaxime, but the two compounds were additive when combined in vitro. For 30 g disks, zone size breakpoints were 27 mm, 28–30 mm and 31 mm for resistant, intermediate and susceptible, respectively. For 1 g disks, those zone size criteria were reduced to 13 mm, 14–16 mm and 17 mm. The 30 g disk that is currently available for testing other species can be used for testing pneumococci; however, the 1 g disk has some important advantages.     

Intrinsic cholinergic excitation in the rat neostriatum: Nicotinic and muscarinic receptors

Summary An in vitro slice technique was employed to study the receptors involved in intrinsic cholinergic excitation in the rat neostriatum. The locally evoked synaptic potentials were suppressed by antinicotinic agents, mecamylamine (10 M), d-tubocurarine (3 M) or hexamethonium (100 M), but not by the antimuscarinic agent atropine (100 M). If the slices were exposed to an acetylcholinesterase (AChE)-inhibitor (paraoxon 1–20 M, physostigmine 0.1–0.5 M), the synaptic potentials were potentiated. The amplitude of the orthodromic population spike increased, and it was further facilitated when the stimulus frequencies were raised from 1–3 Hz to 10–30 Hz. The frequency facilitation following exposure to an AChE-inhibitor was blocked by atropine (1–100 M). Intracellular recording indicated that a slow depolarizing potential caused the frequency potentiation of the orthodromic discharges. Apparently rat neostriatum is similar to cholinergic systems in sympathetic ganglia and spinal Renshaw cells, in that nicotinic receptors mediate fast excitation and muscarinic receptors mediate slow excitation.     

Direct immuno-electron microscopy and some morphological features of hog cholera virus

Summary Characteristic particles of hog cholera virus were identified by direct immuno-electron microscopy. The virion is 40–50m, often asymmetrically shaped, and is enveloped in a membrane that bears 12–15 m surface projections. The surface projections are shear-sensitive and are antigenically different from the virion's envelope. They may represent hog cholera virus soluble antigen.     

Differential expression of β1, β3 and β4 integrins in sarcomas of the small,round, blue cell category

Integrins are a large and complex family of membrane spanning heterodimeric cell surface glycoproteins mediating cell/cell and cell/matrix interactions. Small, round, blue cell sarcomas (SRBCS) are a group of poorly differentiated tumours of various and in part uncertain histogenesis displaying similar cytomorphology. Among them are rhabdomyosarcomas (RMS), ganglioneuroblastomas [(G)NB], primitive peripheral neuroectodermal tumours (pPNET) and Ewing's sarcomas (ES). Thirty-two SRBCS were studied immunohistochemically for the distribution of 1, 3 and 4 integrins in situ. We found complex and to some extent differential patterns of 1, 3 and 4 integrin subunit expression in different types of SRBCS: all of the sarcomas studied were consistently 1⁺, 4^–, 2^–. Four of nine RMS were completely negative for all other integrin subunits studied while one RMS was 5⁺ throughout and three RMS were focally 5⁺. Three RMS expressed the 6 and v chains. In contrast to RMS, pPNET and ES, all of which were 1^–, 3^–, (G)NB were 3⁺ and frequently co-expressed 1. The eight pPNET and seven ES studied showed a similarily restricted integrin profile that was limited to the expression of 1 and 5 in nearly all cases. In summary, RMS were 1⁺, 1^–, 3^– and heterogeneously expressed 5 and 6. (G)NB were generally 1⁺, 1⁺, 3⁺, 5^–, 6^–. pPNET and ES were 1⁺, 1^–, 3^–, 5⁺, 6^–. The data illustrate a complex expression pattern of various integrins in SRBCS, a differential expression pattern of some of the integrin subunits among different types of SRBCS and almost identical integrin profiles in pPNET and ES.This paper is dedicated to Prof. Dr. Dres. h.c. Wilhelm Doerr on the occasion of his 80^th birthday     

Effects of sleep deprivation on the activity of selected metabolic enzymes in skeletal muscle

Summary The present study gives the results of a comparison of the recorded and true tibia-calcaneal angles in 17 normal subjects and in 14 patients with abnormally hypoextensible non contracting triceps. 1. For a minimal passive torque, the difference between true and recorded angles varied considerably from one individual to another. The means and ranges for the two groups were respectively: –8 (+7, –21) and –7 (+5, –20). 2. When the passive torque increased as a result of slow passive lengthening of the muscle, the true curve was steeper than the recorded one, owing to differences between the two angle measurements. For each of the two groups the differences in means and ranges were respectively: 6 (0, +13.5) and 8 (3, 12). 3. Subjects made isometric voluntary contractions of the triceps surae at fixed angles which corresponded to step by step muscle lengthening. The resulting true curve was much steeper than the recorded curve. The differences in means and ranges were: 7 (1.5, +15) in children of the two groups and respectively 3 (0, +9) and 12 (10, 14) in adults of the two groups. The present results show that this methodology was the only reliable way of correctly obtaining passive and active torque-angle curves, measuring differences between subjects, appreciating the effects of treatments and these by ascertaining whether or not trophic muscle regulation was defective.     

Prediction of peak torque and contraction work at different isokinetic angular velocities of plantarflexion

Summary Contraction work (CW) and peak torque (PT) of maximum isokinetic plantar flexions were measured in clinically healthy subjects randomly chosen from the official census list of Umeå, Sweden, in three groups: 40–44, 50–54 and 60–64 years of age, with similar proportions of men and women. Maximum isokinetic plantarflexions were performed at angular velocities of 30, 60, 120 and 180 · s^–1. Body-weight, height and crural circumference were measured. Subjects rated their levels of leisure and occupational activities.To establish formulae to predict CW and PT, stepwise regression procedures were applied. The predictive powers (r ²) of the formulae which incorporated age, sex and crural circumference, were higher for PT (30 · s^–1: 0.82, 60 · s^–1: 0.79, 120 · s^–1: 0.75, 180 · s^–1: 0.56) than for CW (30 s^–1: 0.63, 60 s^–1: 0.63, 120 s^–1: 0.60, 180 s^–1: 0.52). Thus the part of the variance explained decreased with increasing angular velocity, but more than 50% was still explained at 180 s^–1.The results indicate that the mechanical output of the plantar flexors is predictable.     

Differential modulating effects of retinoic acid on interferon antiviral activity

Summary The effect of retinoic acid (RA) on the antiviral activity of interferons (IFNs) and in the U 937 and WISH cells was examined to ascertain whether or not RA could reduce the effectiveness of IFN-induced resistance to viral infection. Our results indicate that in the U 937 cells, RA (0.1–1.0 µM) had neither enhancing nor suppressive effect on the antiviral activity of IFN- or against the Semliki Forest virus (SFV). However, in the WISH cells, RA had different effects on IFNs and . Thus, while RA (0.1–50 µM) invariably suppressed the activity of IFN-, it enhanced the action of IFN- at low dose (0.1–1.0 µM) but became suppressive at higher concentrations ( 10 µM). Furthermore, higher antiviral activity was consistently obtained when RA (0.1–10 µM) was added prior to either IFN- or IFN- comparing to cultures with IFN alone. In addition, direct correlation between antiviral activity and the amplitude of 2–5 oligoadenylate (A) synthetase activity was not observed. These results suggest that modulation of IFN antiviral activity by RA varies with different systems and is dependent on the sequence of treatment.     

The in vitro motility activity of β-cardiac myosin depends on the nature of the β-myosin heavy chain gene mutation in hypertrophic cardiomyopathy

Several mutations in the -myosin heavy chain gene cause hypertrophic cardiomyopathy. This study investigates (1) the in vitro velocities of translocation of fluorescently-labelled actin by -myosin purified from soleus muscle of 30 hypertrophic cardiomyopathy patients with seven distinct -myosin heavy chain gene mutations: Thr124Ile, Tyr162Cys, Gly256Glu, Arg403Gln, Val606Met, Arg870His, and Leu908Val mutations; and (2) motility activity of -myosin purified from cardiac and soleus muscle biopsies in the same patients. The velocity of translocation of actin by -myosin purified from soleus or cardiac muscle of 22 normal controls was 0.48 ± 0.09 m s–1. By comparison, the motility activity was reduced in all 30 patients with -myosin heavy chain gene mutations (range, 0.112 ± 0.041 to 0.292 ± 0.066 m s–1). Notably, the Tyr162Cys and Arg403Gln mutations demonstrated significantly lower actin sliding velocities: 0.123 ± 0.044, and 0.112 ± 0.041 m s–1, respectively. -myosin purified from soleus muscle from four patients with the Arg403Gln mutation had a similar actomyosin motility activity compared to -myosin purified from their cardiac biopsies (0.127 ± 0.045 m s–1 versus 0.119 ± 0.068 m s–1, respectively). Since these seven mutations lie in several distinct functional domains, it is likely that the mechanisms of their inhibitions of motility are different     

Phosphorylation-regulated low-conductance Cl− channels in a human pancreatic duct cell line

A low-conductance Cl^– channel has been identified in the apical membrane of the human pancreatic duct cell Capan-1 using patch-clamp techniques. Cell-attached channels were activated by the vasoactive intestinal polypeptide (VIP, 0.1 mol/l), dibutyryl-adenosine 3,5-cyclic monophosphate (db-cAMP, 1 mmol/l), 8-bromo adenosine 3,5-cyclic monophosphate (8-BrcAMP, 1 mmol/l), 3-isobutyl-1-methyl-xanthine (IBMX, 100 mol/l) and forskolin (10 mol/l). No channel activity was observed in non-stimulated control cells. In both cell-attached and excised inside-out patches, the channel had a linear current/voltage relationship and a unitary conductance of 9 pS at 23°C and 12 pS at 37°C. Its opening probability was not voltage dependent although pronounced flickering was induced at negative potentials. Anionic substitution led to the selectivity sequence Cl^–>I^–>HCO₃ ^–>gluconate. In insideout excised patches, the channel activity declined spontaneously within a few minutes. Reactivation of silent excised channels was achieved by adding protein kinase A (PKA, in the presence of ATP, cAMP and Mg²⁺). Conversely, active channels were silenced in the presence of alkaline phosphatase. The PKA-activated Cl^– channel was 4,4-diisothiocyanatostilbene-2,2-disulphonic acid (DIDS, 100 mol/l) and 4-acetamido-4-isothiocyanatostilbene-2, 2-disulphonic acid (SITS, 100 mol/l) insensitive, but was blocked by diphenylamine-2-carboxylic acid (DPC, 100 mol/l). These results demonstrate that the apical low-conductance Cl^– channel in Capan-1 is regulated on-cell by VIP receptors via cAMP and off-cell by PKA and phosphatases. They provide evidence that this channel is closely related to the cystic fibrosis transmembrane conductance regulator (CFTR) Cl^– channel.     

Virusartige Partikel in den Leukämiezellen eines Säuglings: Elektronenmikroskopischer Vergleich mit Herpes simplex-Virus

Zusammenfassung Leukämiezellen aus dem Knochenmark eines Säuglings wurden durch Oberflächenspreitung und Kritischer-Punkt-Trocknung in Gänze präpariert. Auf die gleiche Weise präparierte Gewebekulturzellen, die mit Herpes simplex-Virus infiziert waren, dienten als Vergleich. Elektronenmikroskopisch fanden sich in den Leukämiezellen vereinzelt virusartige Partikel (Kerne, leere und volle Capside), die in der Morphologie und den Ausreifungsstufen dem Herpes simplex-Virus ähnelten, aber etwas größer waren. Der mittlere Capsiddurchmesser war bei dem Leukämievirus 1240 Å gegenüber 1017 Å bei dem Herpes simplex-Virus. Mit Hilfe der quantitativen Elektronenmikroskopie wurde das Trockengewicht der Viruspartikel bestimmt. Das mittlere Trokkengewicht des Nucleocapsids betrug 19,4 × 10^–16 g für das Leukämievirus und 7,6 × 10^–16 g für das Herpes simplex-Virus.

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Summary Leukemic cells from the bone marrow were prepared as whole-mounts by surface spreading-critical point drying. Tissue culture cells which were infected with herpes simplex virus were prepared by the same method and served as controls. Scattered virus-like particles (cores, empty and full capsids) were found by electron microscopy in the leukemic cells. These particles were similar in morphology and stages of maturation to herpes simplex virus, but differed slightly in size. Mean capsid diameter of the leukemia virus was 1240 Å compared to 1017 Å of herpes simplex virus. Dry mass of the virus particles was determined by quantitative electron microscopy. Mean dry mass of the nucleocapsid was 19.4 × 10^–16 g for the leukemiavirus compared to 7.6 × 10^–16 g for herpes simplex virus.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Caryospora najadae sp.n. (Apicomplexa: Eimeriidae) from Dahl's whip snake,Coluber najadum (Serpentes: Colubridae)

Oocysts of a newCaryospora species,Caryospora najadae, are described from the feces of a Dahl's whip snake,Coluber najadum, from Israel. The spherical oocysts ofC. najadae measure 31.9(27.9–36.3) m in diameter and lack a micropyle and a oocyst residuum. The oocyst wall is between 1.5–2 m thick. The ovoid sporocysts are 15.2(14.0–16.4) m wide and 21.1(19.9–22.2) m long. A sporocyst residuum, a Stieda body and substieda body are present. The sporulation is completed in about 72 h at 21.1±2° C. Sporozoites are elongate measuring circa 19–21×2–2.5 m.     

Absorption,distribution and excretion of the anthelmintic praziquantel (Droncit) in rainbow trout (Salmo gairdneri R.)

Praziquantel is an anthelmintic active against trematodes and cestodes. The absorption, distribution and excretion of the drug was studied in serum, muscles, liver, bile fluid and kidneys of rainbow trout at two temperatures, 12 C and 18 C, after a single oral dose of 500 mg/kg body wt. A bioassay, using cercaria larvae of the trematodeDiplostomum spathaceum as the test organism, was employed to measure the drug levels in tissues of the fish. The cercariae were very sensitive to praziquantel; their mobility was significantly reduced within 20 min in a 0.01 g/ml solution.Praziquantel was readily absorbed from the gastrointestinal tract of the fish. Absorption was more rapid at 18 C than at 12 C. Only in the liver, however, did the peak values reach significantly higher levels at the higher temperature. The peak values in different tissues (10.2–31.8 g/g) were reached 4–16 h after administration of the drug. The elimination of the drug from the tissues was less dependent on temperature than absorption. By 32 h p.a., 67%–96% of the maximum amounts had been eliminated from the tissues. Praziquantel was excreted partly with bile fluid and partly as water-soluble metabolites through the kidneys.     

Electromechanical behaviour of human muscles in vertical jumps

Summary The relationships of muscle structure to the potentiation of myoelectrical activity and to the use of prestretching in five lower limb muscles were studied in different vertical jumping conditions. The subjects for the study were six male students, divided according to the muscle fiber distribution in m. vastus lateralis into fast and slow groups. The subjects performed vertical jumps (1) from a static squatting position (SJ), (2) with a preliminary counter movement (CMJ) and (3) after dropping (DJ) from five different heights. Myoelectrical (EMG) activity was recorded from mm. gluteus maximus, vastus lateralis, vastus medialis, rectus femoris and gastrocnemius in each jumping condition and integrated (IEMG) for the eccentric and concentric phases of contact. EMG activity showed potentiation during the eccentric phase of movement when compared to the concentric phase. The fast and slow groups did not differ significantly in this respect, whereas in DJ conditions the relative (% from SJ) height of rise of the center of gravity was greater in the slow than in the fast group. The result indicated that the utilization of elastic energy during jumping was possible better in subjects having a high percentage of slow twitch muscle fibres in their vastus lateralis muscles.