In vitro activity of the aryl-fluoroquinolones A-56619 and A-56620 and evaluation of disk susceptibility tests

The activity of two new quinolones, A-56619 and A-56620, was compared in vitro to that of norfloxacin and ciprofloxacin against 6,699 bacterial isolates in four separate clinical laboratories. The overall percentage of strains susceptible to designated concentrations were as follows: 99.1% for norfloxacin (MIC4.0 g/ml), 96.1% for ciprofloxacin (MIC1.0 g/ml), 96.8% for A-56620 (MIC 2.0 g/ml) and 96.1% for A-56619 (MIC 4.0 g/ml). For disk diffusion susceptibility tests 10 g A-56619 disks are tentatively recommended with interpretive standards of 18mm for susceptibility and 13mm for resistance; 5 g A-56620 disks may be used with tentative standards of 19mm for susceptibility and 14mm for resistance.     

Decreased serum levels of TGF-β in patients with acutePlasmodium falciparum malaria

Apart from cellular immunity and immunopathology, various cytokines have been implicated in malaria-associated immunosuppression. In this study, serum levels of transforming growth factor- (TGF-) were determined with an enzyme-linked immunosorbent assay in 37 patients with acutePlasmodium falciparum malaria prior to, during, and after therapy and in 17 healthy controls in Bangkok, Thailand. Patients were treated with artesunate and mefloquine. TGF- serum levels were found decreased prior to treatment (14±11 pg/ml versus 63±15 pg/ml in healthy controls;P<0.05). The serum concentrations of TGF- increased after initiation of treatment and were within normal range on day 21. Serum levels of both tumor necrosis factor-ga (TNF-) and soluble TNF-receptor 55 kDa were inversely correlated to serum levels of TGF- (r= –0.667 andr=}-0.592, n=37; respectively,P < 0.05 for both). No correlation between parasitemia and serum levels of TGF- could be found. The results are compatible with a decreased production and release, an enhanced clearance or utilization, or tissue accumulation of TGF- in acuteP. falciparum malaria.     

Unterschiedlich hoher Ureterdruck in Abhängigkeit von der Diureseform beim Hund

Zusammenfassung Bei Vorliegen einer normalen Diurese wird nach Ureterabklemmung der sog. hohe Ureterdruck, unter osmotischer Diurese der maximale erreicht. Die Differenz von Blutdruck und maximalem Ureterdruck war im Mittel der Versuche um 20 mm Hg kleiner als diejenige des hohen. Die Ursache dafür wird kurz diskutiert.Herrn Prof. Dr.S. Janssen zum 70. Geburtstag gewidmet.     

The effects of iron and temperature on the growth ofListeria monocytogenes in cell-free media

The effects of variable iron and temperature on the growth ofL. monocytogenes in vitro was investigated in cell-free tissue culture Medium 199. Two temperatures, 37 and 42C, and varying concentrations of iron (Fe⁺³) derived from ferric ammonium citrate, 40–130g/ml, were selected for the study. Under these conditions,L. monocytogenes exhibited better growth at 37C than at 42C. Dose-effect was demonstrated at every succeeding higher Fe⁺³ concentration except 130g/mI which was inhibitory. The optimal Fe⁺³ concentration at both temperatures was 100g/ml. The implications of these results for tissue culture models and host-parasite relationship, are discussed.     

Effect of theophylline onβ-adrenergic receptor density and cAMP content in bovine aortic smooth muscle cells

Activation of vascular-adrenergic receptors prevents an increase in vascular permeability caused by free radicals or inflammatory peptides. Methylxanthines seem to have similar protective effects on vascular endothelium. In the present study we investigated the effect of theophylline on the-adrenergic receptor expression and cAMP concentrations in cultured endothelial and smooth muscle cells from bovine aorta. Comparable values for-receptor density and binding affinity were detected in both cell types. Isoproterenol induced significant downregulation of-receptors in endothelial (BAEC: –60.5%) and smooth muscle cells (BASMC: –52.5%; P < 0.01). Incubation of endothelial cells with theophylline (4 µg/ml and 40 µg/ml) for 24 hours did not affect-receptor expression, whereas in smooth muscle cells the-receptor density was reduced for –31.5% and –28.7, respectively. In endothelial cells a transient effect on cAMP concentrations was observed after stimulation with isoproterenol (1 µM), but no effect was found in theophylline treated endothelial cells. Stimulation of intact smooth muscle cells with isoproterenol and theophylline (4 µg/ml and 40 µg/ml) resulted in a significant increase of cAMP concentrations after 60 and 240 minutes. The present data suggest a novel, celltype specific effect of theophylline on the-adrenergic receptor expression in vascular smooth muscle cells in vitro.     

Transformation of Cochliobolus lunatus with pUT 720 changes the steroid hydroxylating ability of the fungus

Summary The filamentous fungus Cochliobolus lunatus, a known 11-hydroxylator of steroids, was transformed to bleomycin resistance using the heterologous plasmid pUT 720. This plasmid contains the Sh ble gene expressed under the control of the Aspergillus nidulans gpd and trpC expression signals. The bleomycin-resistant colonies appeared with a frequency of six per g of DNA. All colonies were real transformants and no abortive growth was observed. In all transformants tested the plasmid molecules became stably integrated into the genome of the host, and one of the plasmid molecules integrated in a site-specific manner. Transformants retained the ability to hydroxylate the steroid ring, but the hydroxy group was inserted at the 15 position.     

Structural Model of the Muscle Spindle

A model of the muscle spindle was developed based on its anatomical structure. The model contains three intrafusal fibers (bag1, bag2, and chain), two efferents (dynamic efferent to the bag1 fiber and static efferent to bag2 and chain fibers), and two afferents [primary (Ia) and secondary (II)]. As in the real muscle spindle, the spindle model, under the modulation of efferents, responds to the extrafusal muscle fiber length. Both outputs (Ia and II afferents) of the model were compared extensively with published data, under both sinusoidal stretch (with different stretch amplitudes and frequencies) and ramp and hold stretch (with different stretch amplitudes and velocities) in three different fusimotor activation conditions (dynamic stimulation, static stimulation, and without stimulation). Model Ia afferent responses fit the published data well with active gamma input, but less well in the passive state. Model II afferent responses also fit the published data, although less quantitative data were available for comparison. The model correctly predicted the fractional power dependence of the primary and secondary ending responses on stretch velocity. The current model provides a powerful tool for simulation studies of neuromusculoskeletal systems, and demonstrates the feasibility of using a structural approach to model complex neurophysiological systems. © 2002 Biomedical Engineering Society. PAC02: 8719Ff, 8719La, 8719St     

Effect of an iron supplement on body iron status and aerobic capacity of young training women

Summary Serum iron deficiency has a high incidence in female athletes. We investigated the effects of a daily oral iron supplement, (160 mg) administered during an intensive 7-week physical training programme, on body iron status, and the maximal aerobic capacity (VO_2max) of 13 women (group A) compared to 15 who took a placebo (group B). The subjects were 19 years old. Blood samples were obtained before training began and on days 1, 7, 21 and 42 of training. They were analysed for packed cell volume (PVC) and for haemoglobin (Hb), 2,3-diphosphoglycerate (2,3-DPG), haptoglobin, iron and ferritin concentrations. TheVO_2max was measured on days 0, 21 and 42 of training. Following 21 days of training Hb, PCV and ferritin were significantly higher (P0.01) in group A compared to group B. Over the training period Hb rose by 9.3% and 2.4% in groups A and B, respectively. At the end of training 66% of group B exhibited ferritin concentrations below 10 ng·ml^–1, while none of group A had such low values. MeanVO_2max of group A had increased by 7.5% following 21 days of training (P0.01) and by 15.3% after 42 days. No appreciable increase inVO_2max had occurred in group B by day 21 (significantly lower thanVO_2max of group A;P0.05), however by day 42 it had increased by 14.3% (P0.05). In both groups 2,3-DPG·g Hb^–1 had increased significantly (P0.005) by day 7 (22%) and remained at that level for an additional 35 days. We concluded that a daily oral iron supplement given to young women during intensive training improved several haematological variables and their body iron status. This improvement was associated with an increasedVO_2max only during the early stages of their training (day 21) compared with the placebo group.     

On three new species of the genus Criconemoides Taylor, 1936 (Nematoda: Criconematidae) from North India

Summary The definition of the genus Criconemoides should be extended so as to include those aberrant forms which possess slight cuticular ornamentation. Three new species of the genus Criconemoides Taylor, 1936 are described and illustrated from North India. Criconemoides aberrans n. sp. is distinctive in having 38–43 body annules, rough cuticular outgrowths on the body, 68–78 long spear, bluntly rounded tail, absence of spermatheca and males unknown. Criconemoides neoaxeste n. sp. has 45–49 body annules marked with faint longitudinal lines and rough posterior margins, 65–75 long spear, rounded tail terminus, vulva located at 7th or 8th annule from the posterior end and larva having a cuticular flap with rough margins on each annule. Criconemoides macrolobatus n. sp. is distinguished by 81–86 body annules, very large oval sublateral lobes, 71–75 long spear, tail terminus rounded and the absence of spermatheca and males unknown.

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Zusammenfassung Die Definition der Gattung Criconemoides sollte so erweitert werden, daß auch solche aberranten Formen eingeschlossen werden können, die leichte cuticulare Ornamente besitzen. Drei neue Arten der Gattung Criconemoides Taylor (1936) aus Nordindien werden beschrieben und abgebildet. C. aberrans n. sp. ist deutlich charakterisiert durch 38 bis 43 Körperringe, cuticulare Auswüchse am Körper, 68–78 langen Lanzen, stumpf-abgerundeten Schwanz; Spermatheke fehlt, Männchen nicht bekannt. C. neoaxeste n. sp. hat 45–49 Körperringe mit feiner longitudinaler Linienzeichnung und groben hinteren Rändern, 65–75 lange Lanzen, abgerundetes Schwanzende. Vulva im 7. oder 8. Ring vom hinteren Ende lokalisiert; die Larven haben eine cuticulare Klappe mit groben Rändern an jedem Ring. C. macrolobatus n. sp. ist gekennzeichnet durch 81–86 Körperringe mit sehr breitovalen sublateralen Loben, 71–75 lange Lanzen, Schwanzende abgerundet, Spermatheken fehlen und Männchen unbekannt.

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With 17 Figures in the Text     

Hydration during exercise

Summary Five young unacclimatised subjects were exposed for 4 h at 34 C (10 C dew-point temperature and 0.6 m · s^–1 air velocity), while exercising on a bicycle ergometer: 25 min work — 5 min rest cycles for 2 hours followed by 20 min work — 10 min rest cycles for two further hours. 5 experimental sessions were carried out: one without rehydration (NO FLUID) resulting in 3.1% mean loss of body weight ( M_b), and four sessions with 20 C fluid ingestion of spring water (WATER), hypotonic (HYPO), isotonic (ISO) and hypertonic (HYPER) solutions to study the effects of fluid osmolarity on rehydration. Mean final rehydration (±SE) after fluid intake was 82.2% (±1.2). Heart rate was higher in NO FLUID while no difference among conditions was found in either M_b or hourly sweat rates. Sweating sensitivity was lowest in the dehydration condition, and highest in the WATER one. Modifications in plasma volume and osmolarity demonstrated that NO FLUID induced hyperosmotic hypovolemia, ISO rehydration rapidly led to plasma isoosmotic hypervolemia, while WATER led to slightly hypoosmotic normovolemia.It is concluded that adequate rehydration through ingestion of isotonic electrolyte-sucrose solution, although in quantities much smaller than evaporative heat loss, rapidly restored and expanded plasma volume. While osmolarity influenced sweating sensitivity, the plasma volume changes ( PV) within the range –6% PV+4% had little effect on temperature adjustments in our conditions.     

Combination therapy of cyclosporine with steroid inhibits γ-interferon and interleukin-1 gene expression at the level of mRNA synthesisin vivo

The present study examined the effect of cyclosporine (CsA) administered with steroidin vivo on the capacity of peripheral blood mononuclear cells (PBMC) from kidney transplant recipients to generate cytokines and their gene expression at the level of messenger RNA (mRNA). PBMC from CsA-prednisolone (Pred)-treated recipients displayed 66.9% inhibition (54.3±12.4 IU/ml;N=42;P<0.01) of -interferon (-IFN) production compared with normal individuals (134.6±18.6 IU/ml;N=23). Azathioprine (Az)-Pred-treated recipients displayed significantly less inhibition of -IFN generation (96.0±16.1 IU/ml;N=22;P<0.05) than CsA-treated patients. Macrophages (m) from CsA-Pred-treated recipients displayed 60.0% inhibition (5.1±0.7 U/ml;N=20;P<0.01) of interleukin-1 (IL-1) production compared with normal individuals (13.0±2.9 U/ml;N=21). These results were confirmed by the experiments using cDNA probe for -IFN or IL-1 (, ). High levels of -IFN mRNA in phytohemagglutinin (PHA)-stimulated PBMC or IL-1() mRNA in lipopolysaccharide (LPS)-stimulated m were present in normal individuals but not in CsA-treated recipients as judged by hybridization to a cloned human -IFN or IL-1() cDNA probe. These studies demonstrated that combination therapy of CsA with steroid inhibits both -IFN and IL-1 gene expression at the level of mRNA at physiological concentrations.     

Isoproterenol modulates the calcium channels through two different mechanisms in smooth-muscle cells from rabbit portal vein

Previous data from our laboratory indicated that the slow Ca²⁺ channel of vascular smooth muscle cells was regulated by cyclic nucleotides. In the present study, the effects of isoproterenol (ISO) on L-type calcium current (I _Ca(L)) were investigated in freshly-isolated single smooth-muscle cells from the rabbit portal vein using the whole-cell voltage-clamp technique. With high-Cs⁺ solution in the pipette and physiolocial salt solution (containing 2.0 mM Ca²⁺) in the bath, (I _Ca(L)) was recorded. At a holding potential of –80 mV, low concentrations of ISO ( 100 nM) increased I _Ca, whereas higher concentrations (1–100 M) transiently increased I _Ca but then inhibited it persistently. At 10 M ISO, I _Ca was initially increased by 44±9%, and was subsequently decreased by 24±3%. Pretreatment of cells with 30 M H-7 [1-(5-isoquinolinylsulfonyl)-2-methylpiperazine dihydrochloride] caused the first phase to persist and the second inhibitory phase to disappear. Intracellular application of 1 mM GDP[S] (guanosine 5-O-2-thiodiphosphate) abolished both phases of ISO action. In contrast, intracellular application of 100 M GTP caused the initial stimulatory phase of ISO action to be significantly potentiated; the later inhibitory phase was slightly diminished. In addition, the activated G protein subunit (G_s ) mimicked the stimulatory effect of ISO. Pertussis toxin had no effect on either phase of the ISO action. These results suggest that ISO modulates the Ca²⁺ channel through mechanisms that involve the pertussis-toxin-insensitive G protein(s). That H-7, a nonspecific inhibitor of protein kinases, blocked the second phase but not the first phase indicates that the actions of ISO are mediated via two different pathways. One pathway (for inhibition) is more indirect, and may be mediated by the adenylate cyclase/cAMP/protein-kinase-A cascade. The other pathway (for stimulation) is more direct, and may reflect a type of G protein gating of the Ca²⁺ channel.     

Ca-dependent K channels in smooth muscle cells permeabilized by β-escin recorded using the cell-attached patch-clamp technique

Using the cell-attached patch-clamp technique, the activity of single, Ca-dependent K channels was recorded in single smooth muscle cells permeabilized by -escin. The conductance and the relationship between the open probability of the channels and pCa recorded in permeabilized cells were very similar to those obtained in excised inside-out patches. At pCa 7, application of 30 M acetylcholine (ACh) or 0.1 M substance P (SP) together with 1 mM guanosine 5-trisphosphate to permeabilized cells elicited transient bursts of channel openings similar to those which occur in intact cells. Transient activation was also observed when 2–30 M inositol trisphosphate (IP₃) was applied to permeabilized cells. This single channel activity was inhibited by pretreatment with low-molecular-weight heparin at 50–100 g/ml. Channel activity at pCa 7.0 was greatly enhanced by 200 M cyclic adenosine monophosphate. These results provide direct evidence that single Ca-dependent K channel activity is regulated by the transmitters ACh and SP, as well as a second messenger, IP₃, via the release of intracellular Ca from intracellular sites which are blocked by heparin. This novel approach is valuable in elucidating second messenger mechanisms involved in the regulation of single channel activity by transmitters and autacoids, since permeabilization by -escin preserves the entire system of receptor-operated signal transduction and allows intracellular application of second messengers at fixed concentrations.     

Sustained spontaneous activity of ranvier nodes induced by the combined actions of TEA and lack of calcium

Summary Superfusion of a Ranvier node ofr. esculenta andxenopus l. with Ringer's of reduced Ca⁺⁺-content (0.05 to 0.1 mM/l) containing 5 mM/l TEA, induced spontaneous activity for more than 30 min. The frequency of discharge at beginning of superfusion was 192±39/sec. It declined within 30 to 60 sec to a steady value of 76±26/sec. Such membranes were submitted to voltage clamp analysis: Depolarisations betweenV=0 and 20 mV produced initial, between 0 and 10 mV steady state inward currents. This reversal of steady state currents compared to normal membranes is due to enhanced Na⁺-permeability (lack of Ca⁺⁺) and to reduced K⁺-permeability (action of TEA). Analysis of the sodium system revealed (a) shift of them (V) curve by 10 mV to smaller depolarizations (b) shift of theh (V) curve in same direction by 5 mV (c) little change of time constants _m and _k. The productm ² h near the resting potential differs from zero. Spontaneous activity can thus be explained by the following cycle: After repolarization of the spike the nearly abolished sodium permeability grows toward its steady state value (hh ,mm ). Accordingly the sodium inward current increases with the evolution ofh and produces a depolarization (pacemaker potential) which by the early rise of the variablem becomes regenerative and leads to the next spike.This paper has been presented in a short note to the French Physiological Society in Milan, J. de Physiologie (Paris)59, 349 (1967).     

Immunohistochemical studies on S-100 cells in the anterior pituitary gland of Sprague Dawley rats and spontaneous dwarf rats

The S-100 cells in the pituitary glands of adult male Sprague Dawley rats (SDs) and spontaneous dwarf rats (SDRs) were immunohistochemically examined using anti-S-100 and anti-S-100 monoclonal antibodies. The immunoreactive cells against S-100 protein were divided into three subtypes on the basis of their immunore-activity against subunits of S-100 protein: S-100 dominant type (the -type cell), S-100 dominant type (the \-type cell) and immunoreactive against both S-100 and S-100 (the -type cell). In the SD, -type cells represented 26% of the total S-100 immunoreactive cells (S-100 cells) and were localized in the peripheral area of the ventral region of the pituitary gland. This type of cell was observed forming clusters, with more abundant cytoplasm than the -type cell. The proportion of -type cells was 53%. They were diffusely distributed throughout the gland, and their processes were thicker than those of the -type cell. In the SDR, the proportion of -type cells was 55%, and they were observed throughout the gland. In contrast, -type cells totalled 12% and were localized in small areas of the central and peripheral region of the gland. The proportion of -type cells was 21% in the SD and 33% in the SDR and they were observed forming small clusters in both animal groups. The proportion of -type cells compared with the total of S-100-immunoreactive cells was significantly higher (P < 0.05) in the SDR than in the SD, while the proportion of -type cells was markedly lower (P < 0.05).     

Effect of increasing doses of amikacin with or without piperacillin in the serum bactericidal test

To determine whether high doses of amikacin would prevent the development of resistance in clinical isolates, the serum bactericidal activity and killing rate of conventional and high doses of amikacin and piperacillin alone and in combination were measured in volunteer sera against a series of ten strains each of Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa.Amikacin serum levels were 24.9±6.0 mg/l 1 h after infusion of the 7.5 mg/kg dose and 44.8±5.0 mg/l after the two-fold dose. Median serum bactericidal titers for low dose piperacillin + amikacin were 18–164 and for high-dose piperacillin + amikacin 116–1128. Both were satisfactory, except against piperacillin-resistant Pseudomonas aeruginosa (median bactericidal titers 12), and both combinations had equivalent killing rates.     

In vitro evaluation of the new Paulomycin antibiotic paldimycin

The comparative in vitro activity of paldimycin, a new antibiotic, was evaluated against 215 gram-positive bacteria. Activity of the compound was greater in nutrient agar of pH 6.8 than in Mueller-Hinton agar. All strains of staphylococci, streptococci, enterococci and Listeria monocytogenes were inhibited at concentrations 2 g/ml. Activity of the new drug was generally comparable to that of vancomycin.     

Candida albicans induces the release of inflammatory mediators from human peripheral blood monocytes

Candida albicans (C. albicans) is a major nosocomial pathogen. We examined arachidonic acid (AA) and cytokine production by monocytes stimulated with C. albicans. [¹⁴C]-AA labeled monocytes released 8.9 ±2.3% of the incorporated AA following stimulation with live C. albicans (C. albicans: monocyte of 161) (P=0.0002). Prior studies indicate that soluble-mannans and-glucans antagonize mannose and-glucan receptors, respectively. Preincubation of monocytes with-mannan (100g/ml) caused 45.8 ±5.7% inhibition of [¹⁴C]-AA release, whereas-glucan (100g/ml) yielded 43.7 ±6.0% inhibition (P<0.05 for each compared to control). Additionally, monocytes stimulated with C. albicans also released interleukin-1 (IL-1), tumor necrosis factor- (TNF), interleukin-6 (IL-6) and interleukin-8 (IL-8). However, a-mannan or-glucan failed to inhibit IL-1 release. These data indicate that C. albicans induces monocytes to release AA and inflammatory cytokines. Furthermore, AA, but not cytokine liberation, is partially mediated by a-mannan and-glucan components of the fungus.     

Roles of inositol trisphosphate and protein kinase C in the spontaneous outward current modulated by calcium release in rabbit portal vein

We examined the effects of heparin, guanosine nucleotides, protein kinase C (PKC) modulators, such as phorbol 12,13-dibutylate (PDBu) and H-7 on Ca²⁺-dependent K⁺ currents in smooth muscle cells of the rabbit portal vein using the whole-cell patch-clamp technique, to explore the effects of PKC on the oscillatory outward current (I _oo). Neomycin (30 M), an inhibitor of phospholipase C, and intracellular applications of heparin (10 g/ml) and guanosine 5-O-(2-thiodiphosphate) (GDP[S]; 1 mM) partly but consistently inhibited the generation of I _oo, whereas a higher concentration of heparin (100 g/ml) transiently enhanced then suppressed the generation of I _oo. Inhibition of I _oo generation by heparin was more powerful at the holding potential of + 20 mV than at –20 mV. Inositol 1,4,5-trisphosphate (InsP ₃; 30 M) continuously generated I _oo at holding potentials more positive than –60 mV. Noradrenaline (10 M) and caffeine (3–20 mM) transiently augmented, then reduced the generation of I _oo. Heparin (10 g/ml) completely inhibited responses induced by InsP ₃ and noradrenaline, but not those induced by caffeine. Intracellular application of guanosine 5-triphosphate (GTP; 200 M) or low concentrations of guanosine 5-O-(3-thiotriphosphate) (GTP[S]; 3 M) continuously augmented the generation of I _oo. High concentrations of GTP[S] (10 M) transiently augmented, then inhibited I _oo. Neither GTP[S] nor noradrenaline induced the transient augmentation or the subsequent inhibition of I _oo when applied in the presence of GDP[S] (1 mM), neomycin (30 M) or heparin (10 g/ml). PDBu (0.1 M) reduced the generation of I _oo but failed to produce an outward current following application of caffeine (3–5 mM). This action of PDBu was inhibited by pretreatment with H-7 (20 M). In the presence of H-7, GTP[S] continuously enhanced the generation of I _oo. The suppression of the generation of I _oo during application of noradrenaline (10 M) was reduced by pretreatment with H-7. Thus both InsP₃ and protein kinase C contribute to the generation of I _oo in smooth muscle cells of the rabbit portal vein and heparin is not a specific InsP ₃ antagonist on the InsP ₃-induced Ca²⁺-release channel (PIRC). InsP ₃ opens PIRC and protein kinase C may deplete the stored Ca²⁺ by either inhibiting the reuptake of Ca²⁺ or by enhancement of the releasing actions of InsP ₃.