Apolipoproteins A-I and B in obese children

Body mass index (BMI), the distribution of fat, birth weight, physical fitness, apolipoproteins (apo) A-I and B, total cholesterol (TC), and high-density lipoprotein cholesterol (HDLC) were studied in 38 obese 10- to 11-year-olds in comparison to 52 age-matched controls. Obese children had higher concentration of apo B and a lower apo A-I:B ratio. Significant correlations were found between (a) apo A-I and physical fitness (r = 0.35, p less than 0.015), triceps skinfold thickness (r = 0.44, p less than 0.01), and birth weight (r = -0.33, p less than 0.05); (b) physical fitness and triceps skinfold thickness (r = 0.38, p less than 0.05), and (c) the apo A-I:B ratio and triceps skinfold thickness (r = 0.31, p less than 0.05). When both obese and control children were grouped together, a correlation was found between BMI and TC (r = 0.24, p less than 0.05), apo B (r = 0.37, p less than 0.001), and the apo A-I:B ratio (r = -0.31, p less than 0.01). Multiple regression analyses indicated a significant positive contribution to the apo A-I level by HDLC and physical fitness and a negative one by birth weight

Apolipoprotein A-I:B ratio and B screening: a preliminary study of 10- and 11-year-old children

The apolipoprotein (apo) A-I:B ratio and the apo B concentration were determined by radial immunodiffusion in dried blood spot samples from 1,767 10- and 11-year-old children. Children with either apo A-I:B ratios below the first percentile or apo B levels above the 99th were recalled and plasma lipid and apolipoprotein profiles were determined for both children and parents. Of 17 children (one family was lost to follow-up) recalled due to abnormal apo A-I:B ratios, apo B levels were above the 95th percentile in 13 children, and of 18 children with abnormal apo B screening levels (three of them also had abnormal apo A-I:B ratios), the plasma apo B level was elevated in 13 children. The 23 children with abnormal blood lipid and/or apolipoprotein concentrations were divided into two main groups: (a) children with type IIa hyperlipoproteinemia and (b) children with hyperapo B lipoproteinemia (hyperapo B) and normal blood lipid levels. Twelve children had the type IIa pattern. Five children likely had familial hypercholesterolemia (FH), the other seven children may have hypercholesterolemia due to obesity or environmental factors. Eleven children had the hyperapo B abnormality. In four children, the elevated apo B level probably was an indication of the occurrence of familial combined hypercholesterolemia (FCH) in the family. Of the remaining seven hyperapo B children, three children also had a parent with hyperapo B and a fourth family suffered from obesity

Synthesis of Novel Inhibitors of IdeS, a Bacterial Cysteine Protease Including Studies of Stereoselective Reductive Aminations

Abstract The cysteine protease IdeS is an IgG degrading enzyme secreted by the bacterium Streptococcus pyogenes to evade the human immune system. In this thesis several inhibitors of IdeS have been synthesized and evaluated. Such inhibitors should be highly useful when elucidating the detailed mechanism of IdeS action. They might also have a potential as treatment of acute and severe infections caused by the bacteria. Further, IdeS has a therapeutic application of its own due to the proteolytic ability and an IdeS inhibitor might contribute during the development. Only irreversible, unselective inhibitors of IdeS were known five years ago. In this thesis, three strategies with the aim to synthesize and identify more inhibitors have been undertaken. Focus was first set on compounds with a substructure resembling the known inhibitors but with reversible warheads, i.e. nitrile, azide and aldehyde functions. The aldehyde derivatives were found to provide the first reversible inhibitors of IdeS. Then, to avoid covalent interactions and obtain more selective inhibitors, a substrate based strategy was undertaken. A 3-aminopiperidine fragment was used as replacement of either of the two residues adjacent to the scissile bond in IgG. Such fragments can be synthesized from N-protected 3-aminopiperidone and amino acid esters in reductive aminations in which a stereogenic center is formed. A series of di-, tri- and tetrapeptide analogues, together with eight peptides covering the cleavage site of IgG, were screened for their capacity to inhibit the cysteine proteases IdeS, SpeB and papain. Several analogues showed inhibition capacity, two compounds showed also high selectivity for IdeS. In contrast, none of the tested peptides showed any inhibition. Computational docking studies indicate that the identified IdeS peptide analogues and the non-active peptides do not share the same binding site in IdeS. Probably, the piperidine moiety hinders the inhibitor to enter the catalytic site. A more detailed study of the stereoselectivity in the reductive aminations affording the 3-aminopiperidine fragment showed that a large protecting group (trityl) together with a large reducing agent (NaBH(O-2- ethylhexanoyl)3) gave the highest diastereomeric ratio. The highest ratio obtained was 21:79 when Lproline methyl ester was used. The newly formed stereogenic center had the R-configuration, determined by chemical correlation. Computer based conformational analysis combined with Boltzmann distribution calculations implies an axial attack by the reducing reagent on the intermediary imine. To improve the potency of the two identified di- and tripeptide analogues synthetic routes to conformationally restricted N-containing bicyclic derivatives was undertaken in a third strategy. Five compounds with different bicyclic scaffolds were screened for their inhibition capacity towards IdeS and papain. One of the compounds was able to inhibit the first step of proteolytic cleavage of IgG by IdeS, a process usually completed in seconds

New Hits as Antagonists of GPR103 Identified by HTS

Preclinical data indicate that GPR103 receptor and its endogenous neuropeptides QRFP26 and QRFP43 are involved in appetite regulation. A high throughput screening (HTS) for small molecule GPR103 antagonists was performed with the clinical goal to target weight management by modulation of appetite. A high hit rate from the HTS and initial low confirmation with respect to functional versus affinity data challenged us to revise the established screening cascade. To secure high quality data while increasing throughput, the binding assay was optimized on quality to run at single concentration. This strategy enabled evaluation of a larger fraction of chemical clusters and singletons delivering 17 new compound classes for GPR103 antagonism. Representative compounds from three clusters are presented. One of the identified clusters was further investigated, and an initial structure–activity relationship study is reported. The most potent compound identified had a pIC₅₀ of 7.9 with an improved ligand lipophilic efficiency

Antibody Affinity Against 2009 A/H1N1 Influenza and Pandemrix Vaccine Nucleoproteins Differs Between Childhood Narcolepsy Patients and Controls

Increased narcolepsy incidence was observed in Sweden following the 2009 influenza vaccination with Pandemrix(®). A substitution of the 2009 nucleoprotein for the 1934 variant has been implicated in narcolepsy development. The aims were to determine (a) antibody levels toward wild-type A/H1N1-2009[A/California/04/2009(H1N1)] (NP-CA2009) and Pandemrix-[A/Puerto Rico/8/1934(H1N1)] (NP-PR1934) nucleoproteins in 43 patients and 64 age-matched controls; (b) antibody affinity in reciprocal competitive assays in 11 childhood narcolepsy patients compared with 21 age-matched controls; and (c) antibody levels toward wild-type A/H1N1-2009[A/California/04/2009(H1N1)] (H1N1 NS1), not a component of the Pandemrix vaccine. In vitro transcribed and translated (35)S-methionine-labeled H1N1 influenza A virus proteins were used in radiobinding reciprocal competition assays to estimate antibody levels and affinity (Kd). Childhood patients had higher NP-CA2009 (p = 0.0339) and NP-PR1934 (p = 0.0246) antibody levels compared with age-matched controls. These childhood controls had lower NP-CA2009 (p = 0.0221) and NP-PR1934 (p = 0.00619) antibodies compared with controls 13 years or older. In contrast, in patients 13 years or older, the levels of NP-PR1934 (p = 0.279) and NP-CA2009 (p = 0.0644) antibodies did not differ from the older controls. Childhood antibody affinity (Kd) against NP-CA2009 was comparable between controls (68 ng/mL) and patients (74 ng/mL; p = 0.21) with NP-CA2009 and NP-PR1934 displacement (controls: 165 ng/mL; patients: 199 ng/mL; p = 0.48). In contrast, antibody affinity against NP-PR1934 was higher in controls with either NP-PR1934 (controls: 9 ng/mL; patients: 20 ng/mL; p = 0.0031) or NP-CA2009 (controls: 14 ng/mL; patients: 23 ng/mL; p = 0.0048). A/H1N1-NS1 antibodies were detected in 0/43 of the narcolepsy patients compared with 3/64 (4.7%) controls (p = 0.272). Similarly, none (0/11) of the childhood patients and 1/21 (4.8%) of the childhood controls had A/H1N1-NS1 antibodies. The higher antibody affinities against NP-PR1934 in controls suggest better protection against wild-type virus. In contrast, the reduced NP-PR1934 antibody affinities among childhood narcolepsy patients suggest poor protection from the wild-type A/H1N1 virus and possibly increased risk for viral damage

Antibody Affinity Against 2009 A/H1N1 Influenza and Pandemrix Vaccine Nucleoproteins Differs Between Childhood Narcolepsy Patients and Controls

Increased narcolepsy incidence was observed in Sweden following the 2009 influenza vaccination with Pandemrix(®). A substitution of the 2009 nucleoprotein for the 1934 variant has been implicated in narcolepsy development. The aims were to determine (a) antibody levels toward wild-type A/H1N1-2009[A/California/04/2009(H1N1)] (NP-CA2009) and Pandemrix-[A/Puerto Rico/8/1934(H1N1)] (NP-PR1934) nucleoproteins in 43 patients and 64 age-matched controls; (b) antibody affinity in reciprocal competitive assays in 11 childhood narcolepsy patients compared with 21 age-matched controls; and (c) antibody levels toward wild-type A/H1N1-2009[A/California/04/2009(H1N1)] (H1N1 NS1), not a component of the Pandemrix vaccine. In vitro transcribed and translated (35)S-methionine-labeled H1N1 influenza A virus proteins were used in radiobinding reciprocal competition assays to estimate antibody levels and affinity (Kd). Childhood patients had higher NP-CA2009 (p = 0.0339) and NP-PR1934 (p = 0.0246) antibody levels compared with age-matched controls. These childhood controls had lower NP-CA2009 (p = 0.0221) and NP-PR1934 (p = 0.00619) antibodies compared with controls 13 years or older. In contrast, in patients 13 years or older, the levels of NP-PR1934 (p = 0.279) and NP-CA2009 (p = 0.0644) antibodies did not differ from the older controls. Childhood antibody affinity (Kd) against NP-CA2009 was comparable between controls (68 ng/mL) and patients (74 ng/mL; p = 0.21) with NP-CA2009 and NP-PR1934 displacement (controls: 165 ng/mL; patients: 199 ng/mL; p = 0.48). In contrast, antibody affinity against NP-PR1934 was higher in controls with either NP-PR1934 (controls: 9 ng/mL; patients: 20 ng/mL; p = 0.0031) or NP-CA2009 (controls: 14 ng/mL; patients: 23 ng/mL; p = 0.0048). A/H1N1-NS1 antibodies were detected in 0/43 of the narcolepsy patients compared with 3/64 (4.7%) controls (p = 0.272). Similarly, none (0/11) of the childhood patients and 1/21 (4.8%) of the childhood controls had A/H1N1-NS1 antibodies. The higher antibody affinities against NP-PR1934 in controls suggest better protection against wild-type virus. In contrast, the reduced NP-PR1934 antibody affinities among childhood narcolepsy patients suggest poor protection from the wild-type A/H1N1 virus and possibly increased risk for viral damage