Safety and efficacy of tamoxifen in boys with Duchenne muscular dystrophy (TAMDMD): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Drug repurposing could provide novel treatment options for Duchenne muscular dystrophy. Because tamoxifen-an oestrogen receptor regulator-reduced signs of muscular pathology in a Duchenne muscular dystrophy mouse model, we aimed to assess the safety and efficacy of tamoxifen in humans as an adjunct to corticosteroid therapy over a period of 48 weeks.

METHODS

We did a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial at 12 study centres in seven European countries. We enrolled ambulant boys aged 6·5-12·0 years with a genetically confirmed diagnosis of Duchenne muscular dystrophy and who were on stable corticosteroid treatment for more than 6 months. Exclusion criteria included ophthalmological disorders, including cataracts, and haematological disorders. We randomly assigned (1:1) participants using an online randomisation tool to either 20 mg tamoxifen orally per day or matched placebo, stratified by centre and corticosteroid intake. Participants, caregivers, and clinical investigators were masked to treatment assignments. Tamoxifen was taken in addition to standard care with corticosteroids, and participants attended study visits for examinations every 12 weeks. The primary efficacy outcome was the change from baseline to week 48 in scores on the D1 domain of the Motor Function Measure in the intention-to-treat population (defined as all patients who fulfilled the inclusion criteria and began treatment). This study is registered with ClinicalTrials.gov (NCT03354039) and is completed.

FINDINGS

Between May 24, 2018, and Oct 14, 2020, 95 boys were screened for inclusion, and 82 met inclusion criteria and were initially enrolled into the study. Three boys were excluded after initial screening due to cataract diagnosis or revoked consent directly after screening, but before randomisation. A further boy assigned to the placebo group did not begin treatment. Therefore, 40 individuals assigned tamoxifen and 38 allocated placebo were included in the intention-to-treat population. The primary efficacy outcome did not differ significantly between tamoxifen (-3·05%, 95% CI -7·02 to 0·91) and placebo (-6·15%, -9·19 to -3·11; 2·90% difference, -3·02 to 8·82, p=0·33). Severe adverse events occurred in two participants: one participant who received tamoxifen had a fall, and one who received placebo suffered a panic attack. No deaths or life-threatening serious adverse events occurred. Viral infections were the most common adverse events.

INTERPRETATION

Tamoxifen was safe and well tolerated, but no difference between groups was reported for the primary efficacy endpoint. Slower disease progression, defined by loss of motor function over time, was indicated in the tamoxifen group compared with the placebo group, but differences in outcome measures were neither clinically nor statistically significant. Currently, we cannot recommend the use of tamoxifen in daily clinical practice as a treatment option for boys with Duchenne muscular dystrophy due to insufficient clinical evidence.

FUNDING

Thomi Hopf Foundation, ERA-Net, Swiss National Science Foundation, Duchenne UK, Joining Jack, Duchenne Parent Project, Duchenne Parent Project Spain, Fondation Suisse de Recherche sur les Maladies Musculaires, Association Monegasque contre les Myopathies.

Pharmacokinetics and Pharmacodynamics of a Novel U500 Insulin Aspart Formulation: A Randomized, Double-Blind, Crossover Study in People With Type 1 Diabetes

OBJECTIVE

To evaluate the pharmacokinetics, pharmacodynamics, and safety of a novel U500 insulin aspart formulation (AT278 U500) compared with insulin aspart (IAsp U100).

RESEARCH DESIGN AND METHODS

This single-center, randomized, double-blind study was conducted in 38 men with type 1 diabetes (body weight ≤100 kg and total insulin dose <1.2 units/kg/day). Participants received a single dose of either AT278 U500 or IAsp U100 (0.3 units/kg s.c.) in a crossover design, followed by an 8-h euglycemic clamp in the absence of basal insulin.

RESULTS

With AT278 U500, onset of appearance in serum was 6 min earlier (P < 0.0001) and reached 50% of maximum concentration 23 min faster (P < 0.0001). Insulin exposure with AT278 U500 was 4.0-fold higher within the first 30 min (95% CI 3.29, 4.90), 1.5-fold higher within the first 60 min (95% CI 1.35, 1.76), and statistically superior up to 90 min postdose (P < 0.05). With AT278 U500, onset of action was 10 min earlier (P < 0.0001) and reached 50% of maximum glucose infusion rate 20 min faster (P < 0.0001). The glucose-lowering effect with AT278 U500 was 8.9-fold higher within the first 30 min (95% CI 5.96, 17.46), 2.4-fold higher within the first 60 min (95% CI 1.92, 3.22), and statistically superior up to 2 h postdose (P < 0.0001). Overall insulin exposure and glucose-lowering effect were comparable. No significant safety findings were observed.

CONCLUSIONS

AT278 U500 offers rapid-acting characteristics in a reduced dose volume, with accelerated absorption and onset of action compared with IAsp U100 in the studied population.

Pharmacokinetics and Pharmacodynamics of Three Different Formulations of Insulin Aspart: A Randomized, Double-Blind, Crossover Study in Men With Type 1 Diabetes

OBJECTIVE

To investigate the pharmacokinetic and pharmacodynamic properties and safety of a novel formulation of insulin aspart (AT247) versus two currently marketed insulin aspart formulations (NovoRapid [IAsp] and Fiasp [faster IAsp]).

RESEARCH DESIGN AND METHODS

This single-center, randomized, double-blind, three-period, crossover study was conducted in 19 men with type 1 diabetes, receiving single dosing of trial products (0.3 units/kg) in a random order on three visits. Pharmacokinetics and pharmacodynamics were assessed during a euglycemic clamp lasting up to 8 h.

RESULTS

Onset of insulin appearance was earlier for AT247 compared with IAsp (-12 min [95% CI -14; -8], P = 0.0004) and faster IAsp (-2 min [-5; -2], P = 0.0003). Onset of action was accelerated compared with IAsp (-23 min [-37; -15], P = 0.0004) and faster IAsp (-9 min [-11; -3], P = 0.0006). Within the first 60 min, a higher exposure was observed for AT247 compared with IAsp by the area under the curve (AUC) glucose infusion rate (GIR) from 0 to 60 min (AUC_Asp0-60min: treatment ratio vs. IAsp 2.3 [1.9; 2.9] vs. faster IAsp 1.5 [1.3; 1.8]), which was underpinned by a greater early glucose-lowering effect (AUC_GIR,0-60min: treatment ratio vs. IAsp 2.8 [2.0; 5.5] vs. faster IAsp 1.7 [1.3; 2.3]). Furthermore, an earlier offset of exposure was observed for AT247 compared with IAsp (-32 min [-58; -15], P = 0.0015) and faster IAsp (-27 min [-85; -15], P = 0.0017), while duration of the glucose-lowering effect, measured by time to late half-maximum effect, did not differ significantly.

CONCLUSIONS

AT247 exhibited an earlier insulin appearance, exposure, and offset, with corresponding enhanced early glucose-lowering effect compared with IAsp and faster IAsp. It therefore represents a promising candidate in the pursuit for second-generation prandial insulin analogs to improve postprandial glycemic control.

Analysis of early changes in the articular cartilage transcriptisome in the rat meniscal tear model of osteoarthritis: pathway comparisons with the rat anterior cruciate transection model and with human osteoarthritic cartilage

OBJECTIVE

The purpose of this study was to use microarray technology to: (1) understand the early molecular events underlying the damage of articular cartilage initiated by this surgical procedure, and (2) determine whether these changes mimic those that are occurring in human osteoarthritic (OA) cartilage.

DESIGN

Cartilage was harvested from both medial and lateral sides of the tibial plateaus and femoral condyles of both meniscal tear (MT) and sham surgery groups on days 3, 7 and 21 post-surgery. mRNA prepared from these rat cartilage samples was used for microarray analysis.

RESULTS

Statistical analysis identified 475 genes that were differentially expressed between the sham and MT groups, at one or more of the time points that were analyzed. By integrating these genes with OA-related genes reported previously in a rat OA model and in human OA array studies, we identified 20 commonly changed genes. Six out of these 20 genes (Col5A1, Col6A2, INHBA, LTBP2, NBL1 and SERPINA1) were differentially expressed in two animal models and in human OA. Pathway analysis identified some key features of OA pathology, namely cartilage extracellular matrix remodeling, angiogenesis, and chondrocyte cell death that were recapitulated in the animal models. The rat models suggested increased inflammation and cholesterol metabolic pathways may play important role in early cartilage degeneration.

CONCLUSION

We identified a large number of differentially expressed genes in the articular cartilage of the MT model. While there was lack of overall identity in cartilage gene expression between the rat models and human OA, several key biological processes were recapitulated in the rat MT OA model.

Optimized blood cell profiling method for genomic biomarker discovery using high-density microarray

High-quality biomarkers for disease progression, drug efficacy and toxicity liability are essential for improving the efficiency of drug discovery and development. The identification of drug-activity biomarkers is often limited by access to and the quantity of target tissue. Peripheral blood has increasingly become an attractive alternative to tissue samples from organs as source for biomarker discovery, especially during early clinical studies. However, given the heterogeneous blood cell population, possible artifacts from ex vivo activations, and technical difficulties associated with overall performance of the assay, it is challenging to profile peripheral blood cells directly for biomarker discovery. In the present study, Applied BioSystems' blood collection system was evaluated for its ability to isolate RNA suitable for use on the Affymetrix microarray platform. Blood was collected in a TEMPUS tube and RNA extracted using an ABI-6100 semi-automated workstation. Using human and rat whole blood samples, it was demonstrated that the RNA isolated using this approach was stable, of high quality and was suitable for Affymetrix microarray applications. The microarray data were statistically analysed and compared with other blood protocols. Minimal haemoglobin interference with RNA labelling efficiency and chip hybridization was found using the TEMPUS tube and extraction method. The RNA quality, stability and ease of handling requirement make the TEMPUS tube protocol an attractive approach for expression profiling of whole blood to support target and biomarker discovery.

Ultrastructural localization of sulfated and unsulfated keratan sulfate in normal and macular corneal dystrophy type I

Keratan sulfate (KS) proteoglycans are of importance for the maintenance of corneal transparency as evidenced in the condition macular corneal dystrophy type I (MCD I), a disorder involving the absence of KS sulfation, in which the cornea becomes opaque. In this transmission electron microscope study quantitative immuno- and histochemical methods have been used to examine a normal and MCD I cornea. The monoclonal antibody, 5-D-4, has been used to localize sulfated KS and the lectin Erythrina cristagalli agglutinin (ECA) to localize poly N -acetyllactosamine (unsulfated KS). In normal cornea high levels of sulfated KS were detected in the stroma, Bowman's layer, and Descemet's membrane and low levels in the keratocytes, epithelium and endothelium. Furthermore, in normal cornea, negligible levels of labeling were found for N -acetyllactosamine (unsulfated KS). In the MCD I cornea sulfated KS was not detected anywhere, but a specific distribution of N -acetyllactosamine (unsulfated KS) was evident: deposits found in the stroma, keratocytes, and endothelium labeled heavily as did the disrupted posterior region of Descemet's membrane. However, the actual cytoplasm of cells and the undisrupted regions of stroma revealed low levels of labeling. In conclusion, little or no unsulfated KS is present in normal cornea, but in MCD I cornea the abnormal unsulfated KS was localized in deposits and did not associate with the collagen fibrils of the corneal stroma. This study has also shown that ECA is an effective probe for unsulfated KS.

Characterization of prenylated protein methyltransferase in Leishmania

Prenylated protein methyltransferase, an enzyme involved in the post-translational modification of many signalling proteins, has been characterized in a parasitic flagellated protozoan, Leishmania donovani. The activity of this enzyme was monitored by the methylation of an artificial substrate, an S-prenylated cysteine analogue, with S-adenosyl-l-[methyl-(3)H]methionine as methyl donor. More than 85% of the methyltransferase activity was associated with membranes. The enzyme methylates N-acetyl-S-trans, trans-farnesyl-l-cysteine and N-acetyl-S-all-trans-geranylgeranyl-l-cysteine, but N-acetyl-S-trans, trans-geranyl-l-cysteine only very weakly. In contrast with the enzyme from mammals, the leishmanial enzyme had a greater affinity for the farnesylated substrate than for the geranylgeranylated one. Activity in vitro was not modulated by cAMP, protein kinase C activator or guanosine 5'-[gamma-thio]triphosphate. An analysis of the endogenous substrates showed that the carboxymethylated proteins were also isoprenylated. The main carboxymethylated proteins have molecular masses of 95, 68, 55, 46, 34-23, 18 and less than 14 kDa. Treatment of cells with N-acetyl-S-trans,trans-farnesyl-l-cysteine decreased the carboxymethylation level, whereas treatment with guanosine 5'-[gamma-thio]triphosphate increased the carboxymethylation of various proteins, particularly those of molecular masses 30-20 kDa.

Uptake into leishmania donovani promastigotes and antileishmanial action of an organometallic complex derived from pentamidine

Iridium (Ir)-(COD)-pentamidine tetraphenylborate (CAS 225-75-4) was selected from a primary screening to be evaluated in vitro on three Leishmania (L.) strains comparatively to pentamidine used as reference compound. The IC50 values obtained from in vitro evaluation on promastigotes of L. major CRE 26, L. donovani DD8 and L. donovani LV9 were 3.9, 23.5, and 3.3 mumol/l for Ir-(COD)-pentamidine tetraphenylborate and 1.6, 7.7, and 3.9 mumol/l for pentamidine isethionate, respectively. Cytotoxicity on mouse peritoneal macrophages led to determine a chemotherapeutic index of 1.7 for Ir-(COD)-pentamidine tetraphenylborate and 4 for pentamidine. Considering L. donovani DD8, the uptake of iridium complex by the promastigotes was shown to be saturable with a Km value of 17.4 mumol/l and Vmax of 1.3 nmol/mg protein/2 h. After 2 and 4 h incubation of treated promastigotes in drug free medium the absence of Ir-complex efflux is in favour of intracellular drug binding. As a matter of fact iridium complex was shown to bind ribosomal subunits in vitro, with no effect on macromolecular biosynthesis.

Proton-ATPase activities involved in the uptake of an S-adenosylmethionine analogue

Characteristics of the transport of sinefungin (SF) were studied in Leishmania donovani promastigotes grown in vitro in a semi-defined medium. The uptake is time and pH dependent, temperature sensitive, saturable and independent of the growth phase. Metabolic inhibitors decrease the influx, indicating that sinefungin uptake is an energy requiring process. The presence of Na+ is unnecessary for activity. The uptake is sensitive to valinomycin and nigericin and to the H+-ATPases inhibitors such as N'N'-dicyclohexylcarbodiimide, bafilomycin A and oligomycin. Sulfhydryl group(s) are involved in carrier activity. Use of SF analogues shows, stereospecificity of the transporter, recognition of the 6'-amino group and to a lesser degree of the 9'-amino group of the lateral chain, whereas the 9'-carboxyl group of the lateral chain is not implicated in the recognition. Adenosine and ornithine do not interfere with the uptake. No significant amount of SF is tightly bound to macromolecules. In a SF-resistant clone, though the uptake of SF is reduced (the apparent Vmax is 276 pmoles mg protein(-1) 30 min(-1) compared with 2061 pmoles mg protein(-1) 30 min(-1) for the wild-type clone), the apparent affinity for SF is similar to that of wild-type cells (Km 0.7 and 0.6 microM respectively). This lower uptake activity is not the reflection of an increased efflux of the drug. In these resistant cells, the susceptibility of SF uptake to variation of the external pH, as well as to azide, NaF, and valinomycin are decreased, that to nigericin is lost.

Effects of pentamidine on polyamine level and biosynthesis in wild-type, pentamidine-treated, and pentamidine-resistant Leishmania

Polyamine biosynthesis was studied in wild-type promastigotes of Leishmania donovani and Leishmania amazonensis treated with pentamidine and in the parasites resistant to this drug. Treatment of wild-type clones with low pentamidine concentrations for 24 hr provoked a strong decrease in arginine, ornithine, and putrescine pools, while the level of intracellular spermidine remained unchanged. In these cells, the activity of the enzyme ornithine decarboxylase was found to be decreased. Compared to wild-type cells, resistant clones had a lower level of putrescine, higher pools of arginine and ornithine, and a similar spermidine content. Analysis by Western blot and DFMO-binding showed reduced amount of ornithine decarboxylase. Furthermore, in the resistant cells, the kinetic parameters of the enzyme spermidine synthase were markedly changed, showing increased affinity to putrescine and decreased affinity to pentamidine. Thus, it seems that polyamine biosynthesis pathway is a target of pentamidine in Leishmania and is altered in resistant clones.

Biochemical alterations in paromomycin-treated Leishmania donovani promastigotes

Paromomycin is used for the treatment of leishmaniasis in humans, but little is known about its mechanism of action. Investigating the effect of this antibiotic on promastigotes of Leishmania donovani, we showed that inhibition of the multiplication of these parasites could be related to its effect on RNA synthesis and to modifications of membranous polar lipids and membrane fluidity, leading to altered membrane permeability.

Altered transport properties of pentamidine-resistant Leishmania donovani and L. amazonensis promastigotes

Pentamidine-resistant clones of Leishmania donovani and L. amazonensis promastigotes were developed by increase of the drug pressure in the culture medium and characterized. The resistant clones could grow in 40 and 20 microM pentamidine as determined for L. donovani and L. amazonensis, respectively, with 50% inhibitory concentrations (IC50 values) being 140 and 60 microM, which were 18 and 75 times higher than those recorded for the parental clones, respectively. Biochemical analysis of the clones showed that the acquired pentamidine resistance was specific (no cross-resistance to unrelated drugs and no reversibility with verapamil) and stable in vitro and in vivo. Pentamidine resistance is related to decreased drug uptake and highly increased efflux in both clones of Leishmania spp., accompanied by an alteration in polyamine carriers. Furthermore, a modification of the uptake of pyrimidine nucleosides and several amino acids by these resistant clones indicates alterations in the surface membrane.

Effects of single P-element insertions on bristle number and viability in Drosophila melanogaster

Single P-element mutagenesis was used to construct 1094 lines with P[lArB] inserts on all three major chromosomes in an isogenic background previously free of P elements. The effects of insertions on bristle number and on viability were assessed by comparison to 392 control lines. The variance and effects of P-element inserts on bristle number and viability were larger than those inferred from spontaneous mutations. The distributions of effects on bristle number were symmetrical and highly leptokurtic, such that a few inserts with large effects caused most of the increase in variance. The distribution of effects on viability were negatively skewed and platykurtic. On average, the effects of P-element insertions on bristle number were partly recessive and on viability were completely recessive. P-element inserts with large effects on bristle number tended to have reduced viability, but the correlation between the absolute value of the effects on bristle number and on viability was not strong. Fifty P-element inserts tagging quantitative trait loci (QTLs) with large effects on bristle number were mapped cytogenetically. Two P-element-induced scabrous alleles and five extramacrochaetae alleles were generated. Single P-element mutagenesis is a powerful method for identifying QTLs at the level of genetic locus.

Pentamidine uptake in Leishmania donovani and Leishmania amazonensis promastigotes and axenic amastigotes

A transport system for pentamidine in Leishmania donovani and Leishmania amazonensis promastigotes and axenic amastigotes has been identified and characterized. Pentamidine is not metabolized by these parasites. Its uptake process is saturable, carrier-mediated and energy-dependent. This drug does not inhibit purine or pyrimidine uptake, whereas it inhibits uptake of several amino acids non-competitively and that of putrescine and spermidine competitively. The results suggest that pentamidine shares polyamine-carrier systems in these parasites.

Ribosomes of Leishmania are a target for the aminoglycosides

Ribosomes of Leishmania, a parasitic protozoan (member of the order of Kinetoplastidae), were purified on a sucrose density gradient. Two different types of ribosomes were isolated from the promastigotes: cytoplasmic (88S and 91S from L. tropica and L. donovani, respectively) and mitochondrial (75S in both species). Both types of ribosome dissociated into their subunits at low Mg2+ concentration (1-2 mM) as follows: 67S and 49S for the 91S cytoplasmic ribosomes of L. donovani and 61S and 43S for the 88S cytoplasmic ribosome of L. tropica; 55S and 34S for L. tropica and 60S and 39S for L. donovani mitochondrial ribosomes, respectively. Paromomycin (aminosidine), an aminoglycoside aminocyclitol antibiotic, interacted with the ribosomes to promote the association of the subunits. Under similar experimental conditions, spermidine and pentamidine were inactive.

Sinefungin shares AdoMet-uptake system to enter Leishmania donovani promastigotes

The involvement of a carrier for sinefungin (SF) uptake in Leishmania donovani promastigotes is indicated by saturation kinetics, competition studies and SF accumulation against a 270-fold concentration gradient across the cell membrane. Whether SF uptake occurs via nucleoside- or AdoMet-carrier systems was investigated by competition experiments and comparison of the uptake of various molecules in wild-type and SF-resistant cells. Results show that SF did not inhibit purine or pyrimidine uptake whereas it competitively inhibited AdoMet uptake. Furthermore, the uptake of nucleosides in SF-resistant cells is similar to that in wild-type cells, whereas uptake of SF and AdoMet is lower.

Expression of the major surface glycoprotein of Leishmania, gp63, in wild-type and sinefungin-resistant promastigotes

In this study, we have surveyed gp63 expression in sinefungin-(SF)-resistant and wild-type Leishmania promastigotes. Documentation of gp63 expression in Leishmania promastigotes was carried out by Western blotting, purification of the protein and assessment of gp63 protease activity. We demonstrated a 3-4-fold and 1.5-2-fold increase of gp63 protein in SF-resistant Leishmania donovani and Leishmania tropica promastigotes compared to wild-type, respectively. Northern blot analysis showed that the increase in the amount of gp63 protein in SF-resistant compared to wild-type parasites was concomitant with an increase in gp63 mRNA. No extrachromosomal DNA was identified by alkaline lysis of isolated DNA samples and Southern blot analysis. Treatment of SF-resistant and wild-type L. donovani promastigotes with cycloheximide resulted in an increase of the steady state levels of gp63 mRNA in the SF-resistant parasites to approximately fivefold that of the wild type. After treating parasites with actinomycin D, estimated gp63 mRNA t1/2 in the wild type was 40 min and increased to 83 min in SF-resistant promastigotes. Therefore, the overexpression of gp63 may be mediated, at least in part, by post-transcriptional stabilization of a gp63 transcript by a protein factor. Down regulation of the latter factor may account for the observed increase in gp63 expression in SF-resistant promastigotes. Attempts to correlate gp63 expression with promastigote virulence suggested that the observed increase in gp63 expression did not result in a significant change in the virulence of SF-resistant compared to wild-type L. donovani promastigotes.

Distribution of macromolecular methylations in promastigotes of Leishmania donovani and impact of sinefungin

Sinefungin, an antifungal and antiparasitic nucleoside antibiotic, is a very potent antileishmanial agent both in vitro and in vivo. This molecule, structurally related to S-adenosylmethionine, is a good competitive inhibitor of methyltransferases in vitro. The aim of this report is to analyze the impact of sinefungin on methylation pattern and the subcellular localisation of methyl groups and various methylases in promastigotes of Leishmania donovani. We have shown the presence of various methylated macromolecules in different subcellular fractions, with somewhat higher concentration in membrane fraction. In vitro, sinefungin inhibits the three main protein methylases, but in cells cultured in its presence the protein carboxylmethylations are specifically inhibited.

Characterization of sinefungin-resistant Leishmania donovani promastigotes

Promastigotes resistant to sinefungin (SF), a nucleoside antibiotic that is structurally related to S-adenosylmethionine (AdoMet), were obtained starting from two cloned strains of Leishmania donovani. The resistance was induced by increasing the drug pressure gradually until promastigotes capable of growing in the presence of concentrations 10,000 times higher than the 50% growth-inhibitory (IC50) values for the control cells were obtained. The resistance to SF of both clones was specific and stable in the absence of drug pressure. High-performance liquid chromatographic (HPLC) analyses indicated highly reduced levels of SF in the two resistant clones. However, the intracellular SF concentration in these resistant cells was much higher than the IC50 values for wild-type cells. In one clone, the decreased drug uptake was coupled to a decrease in the affinity of two protein methylases for SF, whereas in the other clone the biosynthesis of polyamine precursors was modified. This study demonstrates that resistance to a drug molecule with pleiotropic targets can be developed through various mechanisms by different strains.

Leishmania donovani: antagonistic effect of S-adenosyl methionine on ultrastructural changes and growth inhibition induced by sinefungin

Sinefungin, an antifungal and antiparasitic nucleoside antibiotic, is a very potent antileishmanial agent in vitro and in vivo (Bachrach et al. 1980, FEBS Letters 121, 287-291; Neal et al. 1985, Transactions of the Royal Society of Tropical Medicine and Hygiene 79, 85-122). It was previously shown that this molecule is a competitive inhibitor of AdoMet for transmethylases (Paolantonacci et al. 1986, Molecular and Biochemical Parasitology 21, 47-54; Avila et al. 1987, Molecular and Biochemical Parasitology 26, 69-76) and that it induces shape changes of Leishmania donovani promastigotes as observed by light microscopy (Lawrence and Robert-Gero 1990; Bulletin de la Societé Française de Parasitologie 8, 13-18). In the present work the effect of the antibiotic on the ultrastructure was analyzed by electron microscopy. The main changes induced at sublethal concentrations (0.26 microM sinefungin for 16 hr) were progressive rounding, decreased motility, enlargement of the flagellar pocket, and shortening and loss of the external part of the flagellum. The comparison with control cells showed shorter Golgi saccules and fragmentation of the trans-Golgi network into vesicles, indicating a stimulated Golgi apparatus activity. This result, associated with the enlarged flagellar pocket, suggests an unbalanced cytoplasmic exchange between exocytosis and endocytosis. These effects are quite different from those induced by tunicamycin (Dagger et al. 1984, Biology of the Cell 50; 173-180) or paromomycin. In addition, other nucleoside and nonnucleoside growth inhibitors failed to induce similar changes. AdoMet antagonized the sinefungin-induced shape changes and ultrastructural modifications but had no effect with respect to other growth inhibitors. This suggests that the sinefungin activity at the cellular level is specifically related to competition with AdoMet. A comparative study of N-methylation and carboxylmethylation of proteins in sinefungin-treated promastigotes showed that the antibiotic preferentially inhibits the latter, catalyzed by protein-O-methyltransferases. These enzymes are known to regulate the function of various proteins involved in secretion. Overall the results suggest that one of the main targets of sinefungin in exponentially growing cells is the protein carboxylmethylation involved in membrane transport.

Total synthesis of uracil analogues of sinefungin

Analogues of sinefungin derivatives 18a and 18b have been prepared from uridine and L-aspartic acid. The key step in the synthesis was the coupling of the radical derived from 14 with the unsaturated amide 13. The latter was produced from the known N-hydroxy-2-thiopyridone ester of L-aspartic acid 12 with the olefin 11. Thus, the essential carbon skeleton was constructed by way of two radical coupling reactions. These analogues as well as 1a and 1b synthesized previously were tested for their antileishmanial effect in vivo and for their inhibitory activity of protein carboxymethylase (protein methylase II). The replacement of the adenine moiety by uracil or dihydrouracil considerably decreases the antiparasitic activity and the affinity for protein methylase II. The synthetic (S)-sinefungin was as active as the natural one. Interestingly, the C-6' epimer 1b was 50% less active in vitro than the natural sinefungin, but both had identical affinities for the target enzyme.

Relationships between steps taken in selecting a nursing home and consumers' satisfaction

Analysis of data related to selection of a nursing home by 411 families of nursing home residents led to the conclusion that steps selected and taken by consumers in the selection of a home were associated with their subsequent satisfaction with the home. Satisfaction was greater (a) for families in agreement about the home selected and (b) for families who investigated all homes in an area before selecting one. Less satisfied were families (a) who were forced to make an immediate decision about placement following illness of a patient, (b) who felt they lacked sufficient time to investigate homes, and (c) who chose the first home with space available.

Synthesis and biological activity of sinefungin analogues

A series of nucleosides (2-4) that derive from adenosine by chain extension at the 5'-end have been synthesized starting from the known phosphonate 7. The latter was first combined with 4-pentenal to give 8, which underwent chemical manipulations to provide triacetate 11, which was found suitable for the adenylation step. Further transformations, among them the Hofmann degradation of the amide group of compound 13, and final deprotection gave nucleosides 2-4. They were considered as analogues of sinefungin (1) and tested for their antileishmanial activity together with compounds 5 and 6, which were obtained independently. All the modifications with respect to sinefungin resulted in nearly complete loss of growth inhibitory activity. These results indicate that the 9' terminal amino and carboxyl groups are necessary for the activity and that the presence of the amino group at C-6' is not sufficient to maintain the antileishmanial effect. Some of the analogues however could antagonize or reverse the inhibitory activity of sinefungin (1).

A comparison of physical activity in Gambian and UK children aged 6-18 months

The activity patterns of 81 Gambian and 53 UK children aged six, 12 or 18 months were compared by means of an activity diary technique. Major differences between communities were observed in the duration of play (2-3 times longer in UK compared to Gambian children) and in the duration of vigorous activities such as crawling, walking and running (2-4 times longer duration in the UK compared to the The Gambia). To investigate whether the lower activity of Gambian children could be explained by differences in nutritional or health status, subgroups of Gambian children were compared. Only small differences in activity pattern were found between Gambian children above and below 80% weight for age and between Gambian children who were or were not diagnosed ill within 10 days of study, suggesting that other factors (e.g. socio-cultural differences or the absence of conventional toys) may explain the lower activity of Gambian compared to UK children.

Bilateral uveal metastases from small-cell carcinoma of the lung

Metastasis from small-cell carcinoma of the lung (SCCL) has most frequently been found in the lymph nodes, bones, brain, and liver. We have reported a case of metastatic SCCL located in the uveal layer of both eyes (choroidal in one and iridic in the other), an extremely rare occurrence.

Energy requirements of pregnancy in The Gambia

At most times of the year adjustments in maternal energy expenditure and energy balance in rural Gambian women can provide sufficient energy to sustain reasonable rates of fetal growth without an increase in food intake, although this study suggests that the overall level of energy intake has been substantially underestimated in the past. At certain times of year, however, pre-harvest food shortages and the energy demands of subsistence farming did substantially reduce maternal fat stores and fetal growth. Dietary supplementation, already known to increase birthweight, also had measurable effects on the mothers' physiology, resulting in increased energy expenditure on basal metabolism and improving maternal fat deposition. These findings suggest that the precise energy cost of pregnancy varies as a function of the additional energy intake consumed at this crucial period.

Inhibition of leishmanial DNA synthesis by sinefungin

RNA, DNA and protein biosynthesis were studied in Leishmania donovani and L. tropica promastigotes cultured with or without sinefungin. Thymidine incorporation was significantly impaired by this compound. Neither the uptake of thymidine nor its phosphorylation were inhibited. Furthermore the ratios of deoxyribonucleotide to the corresponding ribonucleotide were not significantly affected by sinefungin. Analysis of the DNA indicates that the inhibition of thymidine incorporation affects mostly nuclear DNA, kDNA being less affected by this drug. No such effect on thymidine incorporation was observed in macrophages, the host cells of these parasites.

Fat gain during pregnancy in rural African women: the effect of season and dietary status

Body-fat gain during pregnancy (weight--total body water/0.73) was measured in 50 rural Gambian women exposed to seasonal energy demands of subsistence farming and to annual preharvest food shortages. Twenty-eight women received dietary supplements in amounts previously shown to increase birth weight. In unsupplemented women, fat gain was profoundly affected by the seasons through which the pregnancy progressed, ranging from an estimated loss of 4.7 kg to a net gain of 3 kg at various times of the year. Adjustment for season revealed, however, that pregnancy per se was without effect on body fat content. Supplementation increased fat gain during pregnancy by approximately 2 kg (p less than 0.05) and gave protection against the worst effects of season on energy balance. These findings contribute to our understanding of the consequences of low food intake during pregnancy and the effects of dietary supplementation on birth weight.

Protein methylation and protein methylases in Leishmania donovani and Leishmania tropica promastigotes

We studied the content of acid-stable methylated amino acids of soluble proteins in promastigotes of Leishmania donovani and L. tropica. epsilon-N-Trimethyllysine and NG,NG-dimethylarginine were found in both Leishmania species after culture in the presence of [methyl-14C]methionine. In addition, 3-N-methylhistidine was found only in L. tropica and epsilon-N-dimethyllysine only in proteins of L. donovani. As sinefungin, an antileishmanial nucleoside antibiotic, is a known transmethylase inhibitor, its effect on protein methylation was studied, in whole cells and in vitro. In the first case the drug had no effect on the content of methylated amino acid residues of soluble proteins. In vitro, histone methylation by crude extracts was studied at pH 7.2 and 9.0, known in other organisms as optimum pH values for arginine and lysine methylation, respectively. Surprisingly, arginine methylation by extracts of L. donovani was the same at both pH values while lysine residues were more efficiently methylated at pH 7.2 than at pH 9 by the extracts of the two species. These results indicate that the properties of protein methylases I and III of these parasites are different from those of other organisms hitherto studied. The inhibition constants of sinefungin for the leishmanial protein methylases were weak in comparison with those for enzymes from other sources, with the exception of the constant of L. donovani enzyme at pH 9.

The energy cost of common daily activities in African women: increased expenditure in pregnancy?

We have performed, by open-circuit indirect calorimetry, a total of 1546 measurements of energy expenditure on 142 nonpregnant, pregnant, or lactating Gambian village women. Of the 47 common daily activities measured, only 7 would be classified as moderate according to internationally accepted standards, the remainder being light (ie requiring less than 3.5 kcal/min). This was unexpected since many of the tasks, judged subjectively, appeared quite demanding. Furthermore there was no increase towards the end of pregnancy in the energy cost of a range of activities requiring 1-5 kcal/min and involving a variety of body movements, despite the substantial weight gains observed. Only for walking was there the expected increase in energy expenditure. Although in the past it has been assumed that the heavier pregnant women would require additional energy for activity, no special allowance for this is included in current dietary recommendations. The present results indicate that, for women from the developing world, no allowance is necessary. The finding that most activities were light is also of relevance to total energy requirements in this community.

A quantification of child care and infant-caregiver interaction in a West-African village

We have investigated infant-caregiver interactions in an isolated African subsistence farming community where women perform arduous agricultural tasks in addition to their normal domestic duties which include child care. 49 babies aged 3-18 months were studied on one or two occasions. Detailed observations were made of the level of care and of positive and negative stimulation offered to the child. Children were left in the charge of young nursemaids for up to 40% of the day while the mothers tended the crops. Despite this the total amount of positive and negative stimulation and care were similar whether or not the mother was engaged in fieldwork on the day of study. Grandmothers and fathers were both relatively unimportant caregivers. Total positive stimulation did not increase with age; on the contrary, young babies (3-9 months of age) were offered more positive stimulation and less negative stimulation than older ones (12-18 months). A positive correlation was found between total positive stimulation and developmental quotient (assessed by the Griffiths test). Similar amounts of care were given at all ages and there was no difference in the treatment of the two sexes.

Differential effect of sinefungin and its analogs on the multiplication of three Leishmania species

Sinefungin and seven analogs were evaluated in vitro for activity against promastigote multiplication of Leishmania donovani, L. tropica, and L. enrietti. Of these compounds, sinefungin, the cyclic derivative, and A9145C were leishmanicidal at concentrations ranging from 0.13 to 2.6 microM. Sinefungin was the most active of these three compounds against L. donovani, and A9145C was most active against L. enrietti. None of the remaining derivatives exhibited significant activity against any one of the three species at the highest dose tested. All agents were assayed for activity against protein methylases I and III. The results of these tests showed that there is no relationship between the inhibition of growth and inhibition of protein methylases I and III.

Induction of heat shock and stress proteins in promastigotes of three Leishmania species

The induction of heat shock proteins in three species of Leishmania, L. tropica, L. enrietti, and L. donovani is reported. When cultures of promastigotes are shifted from 26 degrees C to 37 degrees C or 40 degrees C, the synthesis of proteins with apparent molecular weights of 88,000, 74,000, and 54,000 is stimulated. Actinomycin D added just prior to the shift prevented the appearance of these proteins but had no effect when present 30 min after the transfer onward, suggesting that the regulation of leishmanial heat shock proteins occurs at the transcriptional level. Exposure of L. tropica promastigotes to sodium arsenite elicits the synthesis of three major and four minor polypeptides. Their apparent molecular weights are, respectively, 94,000, 78,000, and 56,000 and 70,000, 45,000, 22,000, and 18,000. The response of Leishmania organisms to heat shock and to sodium arsenite is similar to that of other organisms, but some of the proteins identified as stress proteins in the parasite differ in size. The heat shock proteins might play a role in cytodifferentiation during the life cycle of the parasite and also in cellular adaptation to higher temperatures.

Maintenance energy cost of pregnancy in rural Gambian women and influence of dietary status

A major assumption in current dietary advice for pregnancy is that the amount of energy expended on tissue maintenance increases by 36 000 kcal over the whole gestation period. In a group of rural Gambian women engaged in subsistence farming, the increase was much smaller and depended on maternal dietary status. In women having the customarily low food intake the net extra cost of tissue maintenance was just 1000 kcal; even in those given a dietary supplement in amounts previously shown to increase birthweight it was only 13 000 kcal. This finding partly explains why mothers, particularly those in the Third World, can apparently accomodate pregnancy without substantially increasing their dietary energy intake. The findings are of importance in the formulation of realistic dietary health strategies for such communities.

Comparative effect of farnesylacetone on macromolecular synthesis in gonads of crustaceans

Farnesylacetone, a molecule isolated from the androgenic glands of Carcinus maenas, inhibits vitellogenesis in the ovaries. Here the effect of farnesylacetone on protein and RNA synthesis in cultured organs is described. Both leucine and uridine incorporation in ovaries were inhibited with low concentration of farnesylacetone. The action was gonad specific and not species specific. It was observable in the presence of cycloheximide but not in the presence of actinomycin. This result plus the fact that inhibition of protein synthesis paralleled that of RNA suggest that farnesylacetone modifies transcription and only indirectly affects protein synthesis.

Gastroenteritis associated with enteric type adenovirus in hospitalized infants

Enteric types of adenovirus have recently been identified as a causative agent of infantile gastroenteritis. We utilized enzyme immunoassay and tissue culture techniques to evaluate prospectively the role of ET Ad in diarrhea occurring in hospitalized infants. We found that ET Ad was associated with 14 of 27 cases of diarrhea occurring during a 12-week study period in the late autumn and early winter months; ET Ad was found in the stool of only one of 72 children without diarrhea (P less than 0.001). Although adenoviruses other than ET Ad were found in the stools of two of the 27 children with diarrhea, such viruses were also found in the stools of five of 72 children without diarrhea and thus could not be statistically correlated with acute gastroenteritis. Children infected with ET Ad had diarrhea for a mean of 8.0 days, compared to a mean duration of 4.2 days for the children with gastroenteritis not associated with ET Ad. Thirteen of the 14 children with ET Ad gastroenteritis had respiratory symptoms such as cough, rhinorrhea, or wheezing, six had roentgenographic evidence of pneumonia, and three children had bilateral conjunctivitis. This study documents that ET Ad can be an important cause of acute gastrointestinal disease in hospitalized infants and young children and that gastrointestinal infections with ET Ad can be associated with a high rate of respiratory disease.

Effect of 5'-deoxy-5'-isobutylthioadenosine on putrescine uptake and polyamine biosynthesis by chick embryo fibroblasts

The effect of 5'-deoxy-5'-S-isobutylthioadenosine (SIBA) on polyamine biosynthesis has been studied by using cultured chick embryo fibroblasts. It has been shown that the drug inhibits the uptake of [14C]putrescine and its conversion into labelled spermidine or spermine. The inhibitory effect is reversed by removing the inhibitor after exposing the cells to the drug for 24 h. SIBA also caused a significant decrease in cellular spermine levels and an accumulation of putrescine. These changes are reversed by removing the inhibitor. SIBA had the same effect on chick embryo fibroblasts transformed by Rous sarcoma virus; a decrease in cellular spermine levels in SIBA-treated cells was observed. In all the experiments SIBA caused a reduction in the spermine/putrescine and spermidine/putrescine ratios. It is suggested that SIBA is not only an inhibitor of transmethylation but also interferes with polyamine biosynthesis, probably by blocking aminopropyltransferase.

Simultaneous decrease in deamination of 5'-adenylic acid and 5'-deoxy-5'-S-isobutylthioadenosine in chick-embryo fibroblasts infected by Rous sarcoma virus

The rate of deamination of 5'-deoxy-5'-S-isobutylthioadenosine [(iBuS5'Ado] in chick embryo fibroblasts was substantially reduced after their infection and morphological transformation by Rous sarcoma virus. Concomitant with the reduction in rate of (iBuS)5'Ado deamination there was a decrease in adenosine deaminase and 5'-adenylic acid deaminase activities. The drop of these activities was related to infection and not to the expression of the src gene. (iBuS)5'Ado was deaminated by at least three enzymes or isoenzymes whose apparent molecular weights have been estimated to be 295000, 121000 and 37000 respectively. Two of these enzymes have been characterized as 5'-adenylic acid deaminase and the heavy form of adenosine deaminase, respectively.

Relationship between inhibition of protein methylase I and inhibition of Rous sarcoma virus-induced cell transformation

A correlation was found between inhibition of protein methylase I and inhibition of virus-induced cell transformation by structural analogs of S-adenosylhomocysteine; all good inhibitors of this enzyme are also good inhibitors of Rous sarcoma virus-induced chicke embryo fibroblast transformation. The inhibitory effect of these analogs was similar on enzymes from normal and transformed cells; no significant variation of the inhibition constants was observed after purification of protein methylase I. From the kinetic constants obtained, a structure-activity relationship can be established for protein methylase I.