First-in-Class Selenium-Containing Potent Serotonin Receptor 5-HT6 Agents with a Beneficial Neuroprotective Profile against Alzheimer's Disease

Alzheimer's disease (AD) has a complex and not-fully-understood etiology. Recently, the serotonin receptor 5-HT6 emerged as a promising target for AD treatment; thus, here a new series of 5-HT6R ligands with a 1,3,5-triazine core and selenoether linkers was explored. Among them, the 2-naphthyl derivatives exhibited strong 5-HT6R affinity and selectivity over 5-HT1AR (13-15), 5-HT7R (14 and 15), and 5-HT2AR (13). Compound 15 displayed high selectivity for 5-HT6R over other central nervous system receptors and exhibited low risk of cardio-, hepato-, and nephrotoxicity and no mutagenicity, indicating its "drug-like" potential. Compound 15 also demonstrated neuroprotection against rotenone-induced neurotoxicity as well as antioxidant and glutathione peroxidase (GPx)-like activity and regulated antioxidant and pro-inflammatory genes and NRF2 nuclear translocation. In rats, 15 showed satisfying pharmacokinetics, penetrated the blood-brain barrier, reversed MK-801-induced memory impairment, and exhibited anxiolytic-like properties. 15's neuroprotective and procognitive-like effects, stronger than those of the approved drug donepezil, may pave the way for the use of selenotriazines to inhibit both causes and symptoms in AD therapy.

Studies on Aryl-Substituted Phenylalanines: Synthesis, Activity, and Different Binding Modes at AMPA Receptors

A series of racemic aryl-substituted phenylalanines was synthesized and evaluated in vitro at recombinant rat GluA1-3, at GluK1-3, and at native AMPA receptors. The individual enantiomers of two target compounds, (RS)-2-amino-3-(3,4-dichloro-5-(5-hydroxypyridin-3-yl)phenyl)propanoic acid 37 and (RS)-2-amino-3-(3'-hydroxybiphenyl-3-yl)propanoic acid 38, were characterized. (S)-37 and (R)-38 were identified as the only biologically active isomers, both being antagonists at GluA2 receptors with Kb of 1.80 and 3.90 μM, respectively. To address this difference in enantiopharmacology, not previously seen for amino acid-based AMPA receptor antagonists, X-ray crystal structures of both eutomers in complex with the GluA2 ligand binding domain were solved. The cocrystal structures of (S)-37 and (R)-38 showed similar interactions of the amino acid parts but unexpected and different orientations and interactions of the biaromatic parts of the ligands inside the binding site, with (R)-38 having a binding mode not previously identified for amino acid-based antagonists.

High frequency ultrasonography: a complementary diagnostic method in evaluation of primary cutaneous melanoma

AIM

The aim of our study was to assess the usefulness of high frequency ultrasonography in the diagnosis of melanoma.

METHODS

We examined 84 patients with suspicious melanocytic skin lesions, including 19 cases of melanoma. In vivo high-resolution ultrasonography (30 MHz) was performed prior to excision.

RESULTS

In ultrasound scans early melanomas presented as flat oval or fusiform shaped structures and were clearly demarcated, while advanced melanomas were characterized by a roundish shape with less distinct borders. The ultrasonographic thickness of in situ melanomas ranged from 0.02 to 0.85 mm. In the case of invasive tumors, the mean thickness evaluated by high frequency ultrasonography was 10.7% higher compared to the Breslow Score (1.44±0.8 mm and 1.3±0.88 mm, respectively). In all melanomas of Breslow Score of 1 mm or more ultrasound also indicated a Breslow Score of 1 mm or more.

CONCLUSION

High frequency ultrasound examination has limited value in differential diagnosis of melanoma, but it gives a clear picture of the size and depth of the tumor. The method should be used as a complementary method (after dermoscopy and, where applicable, reflectance confocal microscopy) in preoperative evaluation of the tumor. In some cases of locally advanced melanoma, ultrasound examination may allow to reduce the number of surgical procedures and favor the decision of a one-time surgical treatment (removal of primary tumor and sentinel lymph node biopsy at the same time).

Congenital hyperinsulinism in Polish patients--how can we optimize clinical management?

INTRODUCTION

Congenital hyperinsulinism of Infancy (CHI) comprises heterogenic defects of insulin secretion with diverse molecular aetiology, histological features, severity of symptoms, and response to pharmacotherapy. The study aimed to establish the first clinical characteristics of Polish patients with CHI and to propose a novel clinical algorithm allowing the prioritisation of genetic and radiology studies, based on patient's characteristics and response to pharmacotherapy.

MATERIAL AND METHODS

Thirty-one patients with CHI were recruited from five reference centres in Poland. Clinical and biochemical parameters were statistically evaluated and compared to those of a control group (n = 30).

RESULTS

CHI predisposes to increased birth weight (p = 0.004), lower Apgar score (p = 0.004), perinatal complications (74%), and neurological implications (48%). Diagnostic process and therapy were inconsistent. A trial of pharmacotherapy was applied in 21 patients (68%), and diagnostic imaging with 18F-L-DOPA PET was performed in only 3. Eighteen patients (58%) were surgically treated, including 8 infants (44%) aged less than 2 months. Depending on the type of resection, further hypoglycaemia was observed postoperatively in 50% (n = 9) and hyperglycaemia in 39% (n = 7) of cases. Based on foregoing results, a clinical algorithm was proposed.

CONCLUSIONS

Standardisation of clinical management with the use of pharmacotherapy, genetic screening, and diagnostic imaging will allow the optimisation of therapy and minimisation of treatment complications.

Membranous glomerulopathy in an adult patient with X-linked agammaglobulinemia receiving intravenous gammaglobulin

BACKGROUND

Immune complex deposition in the subepithelial zone of glomerular capillaries can lead to membranous glomerulopathy.

OBJECTIVE

To present the case of a 23-year-old man with X-linked agammaglobulinemia (XLA) who developed idiopathic membranous glomerulopathy while receiving intravenous immunoglobulin (IVIG).

METHODS

We performed an immunological workup, genetic testing, and a renal biopsy.

RESULTS

XLA was confirmed with less than 0.02% CD19+ cells in the blood after sequence analysis revealed a nonfunctional BTK gene. The patient presented with microhematuria, which persisted for 3 years and spanned treatment with 5 different preparations of intravenous gammaglobulin. Immunohistochemistry revealed membranous glomerulopathy.

CONCLUSION

Although endogenous serum immunoglobulin (Ig) production is severely impaired in XLA, rare B lymphocytes that have managed to mature can produce functional IgG antibodies. The pathogenic immune complexes could reflect IVIG reacting with polymorphic autoantigens, an endogenous IgG-producing clone reacting with a common idiotype present in the IVIG, or both.

The CDR-H3 repertoire from TdT-deficient adult bone marrow is a close, but not exact, homologue of the CDR-H3 repertoire from perinatal liver

Compared with adult bone marrow (BM), the composition of the perinatal liver CDR-3 of the Ig H chain (CDR-H3) repertoire is marked by a paucity of N nucleotides and by enrichment for use of J(H) proximal DQ52 and D(H) proximal V(H) and J(H) gene segments. To test the extent to which these differences reflect limited perinatal TdT activity versus differences in the fetal/adult environment, we used the Hardy scheme to sort fractions B-F B lineage cells from TdT-deficient BALB/c adult BM. V(H)7183-containing VDJCμ transcripts from these cells were amplified, cloned, sequenced, and compared with transcripts from wild-type perinatal liver and adult BM. The pattern of V(H)DJ(H) usage in TdT-deficient BM largely matched that of TdT-sufficient adult cells. What minor differences were detected in the pro-B cell stage tended to diminish with B cell maturation, suggesting strong environmental or Ag-driven pressure to achieve a specific range of V(H)DJ(H) usage regardless of the extent of N nucleotide addition. However, although the patterns of V(H)DJ(H) usage in the TdT-deficient B lineage cells paralleled that of wild-type adult cells, the length distribution, global amino acid composition, and charge distribution of the CDR-H3 repertoire proved to be a close, although not exact, homologue of the CDR-H3 repertoire first expressed by late pre-B cells in the TdT-insufficient perinatal liver. Thus, although differing in V(H) content, TdT-deficient mice appear to represent a good, although not perfect, model for testing the role of perinatal CDR-H3 limitations on late B cell development and Ab responses.

Developmental Regulation of Immunoglobulin CDR-H3 Content through Control of DH and JH Usage in Mice (88.4)

The ability to generate antibodies to specific antigens develops in a controlled, programmed fashion during ontogeny. This process occurs in parallel with the regulated development of antibody repertoire diversity. Compared to adult, the human fetal antibody repertoire is enriched for use of most DH-proximal VH gene segment. The CDR-H3 repertoire is depleted of N nucleotides and enriched for DQ52, the most JH-proximal DH; and for DH-proximal JH2 and 3. The murine fetal antibody repertoire is also enriched for the use of the most DH proximal VH gene segment and depleted of N nucleotides. However, the extent to which DH and JH usage is controlled is unclear. We used surface expression of CD43, BP-1, CD19, IgM and IgD to sort B lineage cells from BALB/cJ perinatal liver, then used RT-PCR to amplify VH7183-containing VDJCμ transcripts. We observed increased use of JH-proximal, DHQ52 and DH-proximal JH2 at all stages of development. Patterns of VH7183-DH-JH usage and CDR-H3 content during B cell development in 18 day fetal liver and neonatal liver were compared to those of adult bone marrow. When evaluated by length and hydrophobicity, evidence of CDR-H3 repertoire selection was most evident in the transition from Hardy Fraction C to D. Our results indicate that regulation of the antibody repertoire ontogeny in mouse shares more similarities with human than previously appreciated. Supported by NIH AI48115.

Serum levels of soluble TNF alpha receptor type I and the severity of systemic sclerosis

Several abnormalities of cytokines have been shown to occur in systemic scleroderma; however their correlation with clinical parameters is controversial. Since serum concentrations of cytokine receptors have been shown to correlate with inflammatory processes, including systemic sclerosis, the aim of our study was to compare serum concentrations of TNF alpha receptor type 1 with the concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), soluble interleukin-2 receptor (sIL-2R) and aminoterminal propeptide of procollagen type III (PIII NP). The findings were correlated with the clinical parameters and antibody patterns, and with the disease severity. Serum samples were studied with the use of enzyme-linked immunosorbent assay (ELISA) or radioimmunoassay (RIA) for sTNF alpha R1, sICAM-1, sIL-2R and PIII NP. The series comprised 36 patients with systemic scleroderma: 13 with diffuse variety and 23 with limited variety, and 7 with Raynaud's disease. Healthy volunteers (n = 25) were chosen from doctors and/or other laboratory staff. Increased levels of sTNF alpha-receptor type 1 were found in 77% of patients with diffuse variety and in only 30% of patients with limited form. Increased serum concentrations in patients with diffuse scleroderma and limited variety were found for sICAM-1 54% and 65%, for sIL-2R 46% and 15%, and for PIIINP 77% and 50%, respectively. There were significant correlations between serum levels of sTNF alpha-receptor type 1 and PIIINP (r = 0.653, p < 0.0001), and sTNF alpha-receptor type 1 and sIL-2R (r = 0.625, p < 0.0001), but not between sTNF alpha-receptor type 1 and sICAM-1 (r = 0.127, p < 0.526). Clinical analysis revealed that serum concentrations of sTNF alpha-RI seem to correlate best with the severity of the disease and, as the only parameter, correlated with lung involvement. The study showed that, in addition to recognized parameters of scleroderma severity (IL-2R, PIIINP), a new important marker appears to be sTNF alpha-receptor type 1.

The effect of dietary selenium deficiency on the antioxidant enzyme system in the gastrointestinal tract of the rat

The effect of selenium deficiency on the glutathione content and antioxidant enzymes in the gastrointestinal mucosa was studied. It was found that under Se-deficiency the level of glutathione increased, whereas the activity of Se-dependent glutathione peroxidase decreased. The activities of catalase and glutathione-S-transferase were unaffected. Malondialdehyde content was markedly increased in the glandular stomach of Se-deficient rats.