Doubling the single-dose infusion rate of tocilizumab in rheumatoid arthritis is safe and efficacious.

OBJECTIVES: To investigate the impact of enhanced infusion rate of tocilizumab on the occurrence of infusion reactions, overall safety, and efficacy in rheumatoid arthritis (RA). METHOD: We conducted a 24-week multicentre, open-label, randomized parallel group study comparing adverse event (AE) and effect profiles following tocilizumab IV 8 mg/kg every 4 weeks over 31 min vs. standard 60-min infusions in patients with RA and an inadequate clinical response to disease-modifying anti-rheumatic drugs (DMARDs) and/or tumour necrosis factor (TNF)-α inhibitors. RESULTS: A total of 47 patients were enrolled in the study and randomized to fast infusions (n = 25) and controls (n = 22). Incidences of infusion reactions were similar between the two groups, neither of them leading to withdrawal. Likewise, the incidence of additional AEs did not differ between the treatment arms. Two serious adverse events (SAEs) were reported, in the control group. Four patients withdrew due to AEs, two from each arm. Efficacy at week 24 was comparable between groups. CONCLUSIONS: In RA, monthly tocilizumab infusions of 8 mg/kg provided over 31 or 60 min during 24 weeks did not differ concerning safety or efficacy.

Physiological changes in maternal cortisol do not alter expression of growth-related genes in the ovine placenta.

OBJECTIVES: The aim of this study was to investigate the effect of cortisol on growth-related genes in the ovine placenta. STUDY DESIGN: Ewes carrying singleton pregnancies were operated on between 112 and 116 days of gestation (115 ± 0.4, term = 147 days) and randomly assigned into three groups: six control animals, five ewes that were administered cortisol by continuous intravenous infusion (1 mg/kg/day, high cortisol), and five ewes that were adrenalectomized and replaced with 0.5-0.6 mg cortisol/kg/day and 3 µg aldosterone/kg/day to produce cortisol concentrations equivalent to pre-pregnancy values (low cortisol). At necropsy (130 ± 0.2 days of gestation), placental tissue was frozen and stored at -80 °C for mRNA analysis. MAIN OUTCOME MEASURES: To assess potential molecular mechanisms by which cortisol alters placental structure and function and fetal growth. RESULTS: Cortisol levels did not significantly affect 11ß-hydroxysteroid dehydrogenase 1 and 2 enzymes, glucocorticoid receptor, mineralocorticoid receptor and angiotensin II receptor, type 1 (AT1R) expression levels. Gene expression levels of AT2R were increased in the high cortisol group for type B placentomes. There was little effect of cortisol on the insulin-like growth factor (IGF) axis. There was significantly more IGF-I mRNA in B versus A type and more IGFBP-2 mRNA in B and C type versus A type placentomes regardless of treatment (p < 0.05). CONCLUSIONS: These data suggest that cortisol increases placental AT2R expression at high concentrations whereas it has little effect on the placental IGF axis.

Adenosine A(1) receptor mediated suppression of adrenal activity in near-term fetal sheep.

Activation of the hypothalamic-pituitary-adrenal (HPA) axis is a critical response to perinatal hypoxia. Recent data show that adenosine appears to inhibit baseline levels of fetal cortisol and to restrict the increase in ACTH and cortisol during moderate hypoxia. Because adenosine increases substantially during profound asphyxia, it is possible, but untested, that counterintuitively it might restrict the HPA response to more severe insults. It is unclear which receptors mediate the effects of adenosine on the HPA axis; however, adenosine A(1) receptor activation is important for adaptation to hypoxia. We therefore investigated whether adenosine A(1) receptor blockade modulates ACTH and cortisol levels in fetal sheep at 118 to 126 days gestation, randomly allocated to receive an intravenous infusion of either vehicle (vehicle-occlusion, n = 7) or 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, an A(1) receptor antagonist, DPCPX-occlusion, n = 7) infused 60 min before and during 10 min of umbilical cord occlusion, or infusion of DPCPX for 70 min without occlusion (DPCPX-sham, n = 6). Experiments were terminated after 72 h. Fetal ACTH levels increased significantly (P < 0.01) during occlusion, but not sham occlusion, and returned to baseline values by 60 min after occlusion. In the vehicle-occlusion group, fetal cortisol and cortisone plasma levels increased significantly (P < 0.05) 60 min after the occlusion and returned to baseline values by 24 h. In contrast, there was a marked increase in both fetal cortisol and cortisone during DPCPX infusion before occlusion to a level greater even than the maximum rise seen after occlusion alone. This increase was sustained after occlusion, with increased cortisol levels compared with occlusion alone up to 72 h. In conclusion, fetal cortisol concentrations are suppressed by adenosine A(1) receptor activity, largely though a direct adrenal mechanism. This suppression can be partially overcome by supraphysiological stimuli such as asphyxia.

Post-hypoxic hypoperfusion is associated with suppression of cerebral metabolism and increased tissue oxygenation in near-term fetal sheep.

Secondary cerebral hypoperfusion is common following perinatal hypoxia-ischaemia. However, it remains unclear whether this represents a true failure to provide sufficient oxygen and nutrients to tissues, or whether it is simply a consequence of reduced cerebral metabolic demand. We therefore examined the hypothesis that cerebral oxygenation would be reduced during hypoperfusion after severe asphyxia, and further, that the greater neural injury associated with blockade of the adenosine A(1) receptor during the insult would be associated with greater hypoperfusion and deoxygenation. Sixteen near-term fetal sheep received either vehicle or 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) for 1 h, followed by 10 min of severe asphyxia induced by complete occlusion of the umbilical cord. Infusions were discontinued at the end of the occlusion and data were analysed for the following 8 h. A transient, secondary fall in carotid artery blood flow and laser Doppler flow was seen from approximately 1-4 h after occlusion (P < 0.001), with no significant differences between vehicle and DPCPX. Changes in laser Doppler blood flow were highly correlated with carotid blood flow (r(2)= 0.81, P < 0.001). Cortical metabolism was suppressed, reaching a nadir 1 h after occlusion and then resolving. Cortical tissue P(O(2)) was significantly increased at 1, 2 and 3 h after occlusion compared to baseline, and inversely correlated with carotid blood flow (r(2)= 0.69, P < 0.001). In conclusion, contrary to our initial hypothesis, delayed posthypoxic hypoperfusion was associated with suppression of cerebral metabolism and increased tissue P(O(2)), and was not significantly affected by preceding adenosine A1 blockade. These data suggest that posthypoxic hypoperfusion is actively mediated and reflects suppressed cerebral metabolism.

Chronic pulsatile infusion of growth hormone to growth-restricted fetal sheep increases circulating fetal insulin-like growth factor-I levels but not fetal growth.

Intra-uterine growth restriction (IUGR) is a major cause of perinatal mortality and morbidity. Postnatally, growth hormone (GH) increases growth, increases circulating insulin-like growth factor (IGF)-I levels, and alters metabolism. Our aim was to determine if GH infusion to IUGR fetal sheep would alter fetal growth and metabolism, and thus provide a potential intra-uterine treatment for the IUGR fetus. We studied three groups of fetuses: control, IUGR+ vehicle and IUGR+GH (n=5 all groups). IUGR was induced by repeated embolisation of the placental vascular bed between 110 and 116 days of gestation (term=145 days). GH (3.5 mg/kg/day) or vehicle was infused in a pulsatile manner from 117 to 127 days of gestation. Embolisation reduced fetal growth rate by 25% (P<0.01) and reduced the weight of the fetal liver (20%), kidney (23%) and thymus (31%; all P<0.05). GH treatment further reduced the weight of the fetal kidneys (32%) and small intestine (35%; both P<0.04), but restored the relative weight of the fetal thymus and liver (P<0.05). Embolisation decreased fetal plasma IGF-I concentrations (48%, P<0.001) and increased IGF binding protein 1 (IGFBP-1) concentrations (737%, P<0.002). GH treatment restored fetal plasma IGF-I concentrations to control levels, while levels in IUGR+vehicle fetuses stayed low (P<0.05 vs control). IGFBP-1 and IGFBP-2 concentrations were about sevenfold lower in amniotic fluid than in fetal plasma, but amniotic and plasma concentrations were closely correlated (r=0.75, P<0.0001 and r=0.55 P<0.0001 respectively). Embolisation transiently decreased fetal blood oxygen content (40%, P<0.002), and increased blood lactate concentrations (213%, P<0.04). Both returned to pre-embolisation levels after embolisation stopped, but blood glucose concentrations declined steadily in IUGR+vehicle fetuses. GH treatment maintained fetal blood glucose concentrations at control levels. Our study shows that GH infusion to the IUGR fetal sheep restores fetal IGF-I levels but does not improve fetal growth, and further reduces the fetal kidney and intestine weights. Thus, fetal GH therapy does not seem a promising treatment stratagem for the IUGR fetus.

The effect of a chronic maternal cortisol infusion on the late-gestation fetal sheep.

Exposure of the fetus to excess maternal glucocorticoids has been postulated to alter fetal growth and development, and thus provide a possible mechanism for the link between impaired fetal growth and altered postnatal physiology. However, the effects of exposure to excess maternal glucocorticoids on fetal physiology and metabolism in utero have not been described. We therefore studied the effects of chronic maternal cortisol infusion on fetal growth, blood pressure, metabolism and endocrine status in chronically catheterised fetal sheep. We infused hydrocortisone (80 mg/day, n=6) or saline (n=8) for 10 days into the pregnant ewes beginning at 119 days of gestation. Maternal cortisol infusion reduced fetal growth rate by 30% (girth increment 2.9+/-0.3 vs 1.8+/-0.4 mm/day, P=0.03). Maternal cortisol infusion increased fetal heart weight by 15% relative to body weight and increased ventricular wall thickness by 30% in the left and 50% in the right ventricle. The weight of the spleen was reduced by 30% and placental weight reduced by 25%. Fetal blood pressure increased by approximately 10 mmHg (20%) during maternal cortisol infusion. Maternal cortisol infusion did not alter amino-nitrogen concentrations. However, maternal lactate concentrations increased by 80% and fetal lactate concentrations increased by 74% with maternal cortisol infusion, and both maternal and fetal urea concentrations increased by 40%. Circulating maternal IGF-binding protein (IGFBP)-3 levels had increased by 20% by the end of the maternal cortisol infusion. Fetal IGF-I concentrations decreased during cortisol infusion and fetal IGFBP-1 concentrations were negatively correlated with fetal weight (r=-0.76, P=0.02). We conclude that even a modest elevation of maternal cortisol levels affects fetal growth, cardiovascular function, metabolism and endocrine status which may have long-term consequences.

Quorum sensing in the dimorphic fungus Candida albicans is mediated by farnesol.

The inoculum size effect in the dimorphic fungus Candida albicans results from production of an extracellular quorum-sensing molecule (QSM). This molecule prevents mycelial development in both a growth morphology assay and a differentiation assay using three chemically distinct triggers for germ tube formation (GTF): L-proline, N-acetylglucosamine, and serum (either pig or fetal bovine). In all cases, the presence of QSM prevents the yeast-to-mycelium conversion, resulting in actively budding yeasts without influencing cellular growth rates. QSM exhibits general cross-reactivity within C. albicans in that supernatants from strain A72 are active on five other strains of C. albicans and vice versa. The QSM excreted by C. albicans is farnesol (C(15)H(26)O; molecular weight, 222.37). QSM is extracellular, and is produced continuously during growth and over a temperature range from 23 to 43 degrees C, in amounts roughly proportional to the CFU/milliliter. Production is not dependent on the type of carbon source nor nitrogen source or on the chemical nature of the growth medium. Both commercial mixed isomer and (E,E)-farnesol exhibited QSM activity (the ability to prevent GTF) at a level sufficient to account for all the QSM activity present in C. albicans supernatants, i.e., 50% GTF at ca. 30 to 35 microM. Nerolidol was ca. two times less active than farnesol. Neither geraniol (C(10)), geranylgeraniol (C(20)), nor farnesyl pyrophosphate had any QSM activity.

[Blindness in temporal arteritis despite prednisolone treatment]. / Blindhed ved arteritis temporalis trods prednisolonbehandling.

Giant cell arteritis occurs most commonly in elderly individuals. The lesion is usually restricted to major arteries. Other arteries can be involved e.g. posterior ciliar artery, which is an important complication, because of the risk of blindness. It is commonly accepted, that blindness will not occur after corticosteroid has been initiated. In this article however, a patient is described who became blind on both eyes in spite of initially moderate doses of corticosteroid.

Effect of IGF-I on serine metabolism in fetal sheep.

Acute infusion of IGF-I to the fetus has been shown to inhibit amino acid oxidation and appears to increase fetoplacental amino acid uptake. This study was designed to investigate further the effects of IGF-I on fetal amino acid metabolism. Radiolabeled serine was used to test the hypothesis that fetal IGF-I infusion enhances serine uptake into the fetus and/or placenta and inhibits serine oxidation. Eight fetal sheep were studied at 127 days of gestation before and during a 4-h infusion of IGF-I (50 microg/h per kg). During the infusion there was no change in uptake of serine or its oxidation by fetus or placenta. However, both uptake and oxidation of serine and glycine decreased in the fetal carcass. There was also a decrease in fetal blood serine and glycine concentrations which could indicate a decrease in protein breakdown, although reduced amino acid synthesis cannot be excluded. Thus IGF-I appeared to influence the distribution of these amino acids as oxidative substrates between different fetal tissues. In addition, fetal IGF-I infusion increased the conversion of serine to glycine which is likely to have increased the availability of one-carbon groups for biosynthesis. Our data provide further evidence that IGF-I plays a role in the regulation of fetoplacental amino acid metabolism.

Metabolic effects of IGF-I in the growth retarded fetal sheep.

It has been shown that IGF-I has an anabolic effect in the normal fetus. However, there is evidence to suggest that there may be IGF-I resistance in the growth retarded fetus. Therefore, we investigated the effects of acute IGF-I infusion to chronically catheterised fetal sheep. At 128 days gestation, fetuses underwent a 4 h infusion of IGF-I (50 microg/kg/h). Three groups of animals were studied. Nine normally grown fetuses were studied as controls. Embolised animals (n=8) received microspheres into the uterine vasculature, and animals with spontaneous intra-uterine growth retardation (IUGR animals) (n=6) were fetuses found at post mortem to be spontaneously growth restricted. The effects of IGF-I infusion on feto-placental carbohydrate and protein metabolism were similar in our control group to previous similar experiments. IGF-I infusion decreased fetal blood glucose, oxygen, urea and amino-nitrogen concentrations, and inhibited placental lactate production. The same fetal blood metabolite concentrations also fell during IGF-I infusion in the embolised fetuses, but the effect on placental lactate production was not seen. The only effect of IGF-I infusion in the spontaneous IUGR animals was a fall in fetal blood amino-nitrogen concentrations. We conclude that fetal IGF-I infusion does not have the same anabolic effects in the growth retarded fetus as the normal fetus. In addition, the effects of IGF-I were different in the two growth retarded groups. Our data support previous evidence that the growth retarded fetus has altered IGF-I sensitivity, and this may vary depending on the cause, severity and duration of growth retardation.

Prevalence of broad-host-range lytic bacteriophages of Sphaerotilus natans, Escherichia coli, and Pseudomonas aeruginosa.

Two bacteriophage collections were examined with regard to their ability to form plaques on multiple bacterial host species. Nine of 10 phages studied were found to be broad-host-range bacteriophages. These phages fell into two groups. Group 1, the SN series, was isolated from sewage treatment plant samples with Sphaerotilus natans ATCC 13338 as a host. The DNAs of these bacteriophages contained modified bases and were insensitive to cleavage by type I and II restriction endonucleases. The efficiency of plating of these bacteriophages was changed only slightly on the alternate host. Group 2, the BHR series, was isolated by a two-host enrichment protocol. These bacteriophages were sensitive to restriction, and their efficiency of plating was dramatically reduced on the alternate host. Our results suggest that a multiple-host enrichment protocol may be more effective for the isolation of broad-host-range bacteriophages by avoiding the selection bias inherent in single-host methods. At least two of the broad-host-range bacteriophages mediated generalized transduction. We suggest that broad-host-range bacteriophages play a key role in phage ecology and gene transfer in nature.

Lipoxygenase inhibitors shift the yeast/mycelium dimorphism in Ceratocystis ulmi.

The yeast-mycelium dimorphism in Ceratocystis ulmi, the causative agent of Dutch elm disease, was switched by gossypol, nordihydroguaiaretic acid, and propylgallate. In each case the mycelial form was converted to the yeast form. These compounds are recognized lipoxygenase inhibitors. Inhibitors of cyclooxygenase and thromboxane synthetase did not cause mycelia to shift to the yeast form. We suggest the following two-part hypothesis: (i) that lipoxygenase is a target for antifungal antibiotics and (ii) that many phytoalexins (antimicrobial compounds of plant origin) are targeted toward fungal lipoxygenases. In addition, in a study to determine potential lipoxygenase substrates, a fatty acid analysis indicated that C. ulmi conidiospores contained high levels of oleic, linoleic, and linolenic acids but no arachidonic acid.

Chiral drugs: an industrial analytical perspective.

In the pharmaceutical industry, chiral drug candidates introduce a unique set of challenges to all disciplines involved in the drug development process. For the analytical chemist in particular, the generation of relevant information about a variety of stereoisomeric issues is necessary. Chiral drug candidates, whether a single isomer or a mixture of isomers, require more analytical information than achiral drug candidates. This information can be derived from enantioselective spectroscopic and chromatographic techniques. Chiral analytical methods require proper development and validation to ensure accurate results. Issues related to method development and validation for complete stereochemical characterization are discussed, with primary emphasis on the generation of analytical data required for the registration of a chiral drug candidate. The presentation of pertinent analytical data depends on an awareness of the problems encountered during the development process and the appropriate use of methodology for the determination of stereoisomeric purity.

Comparative veterinary hematology: a bird's eye view.

A comparative look at veterinary hematology in the class Mammalia is presented to acquaint the medical technologist with a new dimension in clinical pathology. Aspects of clinical hematology, such as erythrocyte and leukocyte morphologies, dynamics, and diseases, are discussed.