Familial adenomatous polyposis: desmoid tumours and lack of ophthalmic lesions (CHRPE) associated with APC mutations beyond codon 1444

An earlier study has shown that FAP patients with mutations in codons 136-302 of the APC gene do not develop congenital hypertrophy of the retinal pigment epithelium (CHRPE), whereas those with mutations in codons 463-1387 regularly do. Here we present data on 36 patients from 20 families with mutations in codons 1445-1578. These patients lack CHRPE. Furthermore, with the exception of three prepubertal children all patients with mutations in codons 1445-1578 developed desmoid tumours. This relationship between certain extracolonic manifestations and site of the APC mutation points to a specific role of the APC protein in different tissues.

Resident pulmonary lymphocytes expressing the gamma/delta T-cell receptor

The biological role of cells bearing the gamma delta T-cell antigen receptor (TCR) is as yet unclear. Although there are indications that some gamma delta+ cells can mediate cytotoxicity, their antigen-related functions have not yet been defined. In the mouse, gamma delta+ cells constitute 1-3% of T cells in lymphoid organs. Intestinal intraepithelial lymphocytes (IELs) and dendritic epidermal cells (DECs) also appear to carry the gamma delta TCR. The strategic locations of DECs and IELs have led to the suggestion that gamma delta+ cells could constitute a first line of defence in the vicinity of large surfaces of contact with the environment. We report here that an estimated 8-20% of resident pulmonary lymphocytes (RPLs) are CD3+ alpha beta TCR-, and presumably gamma delta TCR+. Furthermore, mice exposed to aerosols containing a Mycobacterium tuberculosis extract have an increased number of activated CD3+ alpha beta-TCR- pulmonary T cells which can be propagated in vitro.

Primary structure of human T-cell receptor alpha-chain

The T-cell receptor has been studied intensely over the past 10 years in an effort to understand the molecular basis for major histocompatibility complex (MHC) restricted antigen recognition. The use of anti-receptor monoclonal antibodies to isolate and characterize the receptor from human and murine T-cell clones has shown that the protein consists of two disulphide-linked glycopeptides, alpha and beta, distinct from known immunoglobulin light and heavy chains. Like immunoglobulin light and heavy chains, however, both the alpha- and beta-chains are composed of variable and constant regions. Molecular cloning has revealed that the beta-chain is evolutionarily related to immunoglobulins, and is encoded in separate V (variable), D (diversity), J (joining) and C (constant) segments that are rearranged in T cells to produce a functional gene. We report here cDNA clones encoding the alpha-chain of the receptor of the human T-cell leukaemia line HPB-MLT. Using these cDNA probes, we find that expression of alpha-chain mRNA and rearrangement of an alpha-chain V-gene segment occur only in T cells. The protein sequence predicted by these cDNAs is homologous to T-cell receptor beta-chains and to immunoglobulin heavy and light chains, particularly in the V and J segments.

The "three delays" as a framework for examining maternal mortality in Haiti

Haiti has one of the highest rates of maternal mortality in the Caribbean. The "Three Delays" model proposes that pregnancy-related mortality is overwhelmingly due to delays in: (1) deciding to seek appropriate medical help for an obstetric emergency; (2) reaching an appropriate obstetric facility; and (3) receiving adequate care when a facility is reached. This framework was used to analyze a sample of 12 maternal deaths that occurred in a longitudinal cohort of pregnant Haitian women. Because of political upheavals in Haiti during the survey, these deaths are an underestimate of all deaths that occurred in the cohort. Family and friend interviews were used to obtain details about the medical and social circumstances surrounding each death. A delayed decision to see medical care was noted in eight of the 12 cases, whereas delays in transportation only appeared to be significant in two. Inadequate care at a medical facility was a factor in seven cases. Multiple delays were relevant in the deaths of three women. Family and friend interviews suggest that a lack of confidence in available medical options was a crucial factor in delayed or never made decisions to seek care. Expanding the coverage of existing referral networks, improving community recognition of obstetric emergencies, and improving the ability of existing medical institutions to deliver quality obstetric care, are all necessary. However, services will continue to be under-utilized if they are perceived negatively by pregnant women and their families. The current data thus suggest that improvements to Haiti's maternity care system which focus on reducing the third delay--that is, improving the quality and scope of care available at existing medical facilities--will have the greatest impact in reducing needless maternal deaths.

Overexpression of tumor necrosis factor-alpha produces an increase in lung volumes and pulmonary hypertension

Tumor necrosis factor (TNF)-alpha is a key proinflammatory cytokine that is thought to be important in the development of pulmonary fibrosis, whereas its role in pulmonary emphysema has not been as thoroughly documented. In the present study, TNF-alpha was overexpressed in alveolar type II cells under the control of the human surfactant protein C promoter. In this report, we further characterized the pulmonary abnormalities and provided a physiological assessment of these mice. Histopathology of the lungs revealed chronic inflammation, severe alveolar air space enlargement and septal destruction, and bronchiolitis. However, pulmonary fibrosis was very limited and only seen in the subpleural, peribronchiolar, and perivascular regions. Physiological assessment showed an increase in lung volumes and a decrease in elastic recoil characteristic of emphysema; there was no evidence of restrictive lung disease characteristic of pulmonary fibrosis. In addition, the mice raised in ambient conditions in Denver developed pulmonary hypertension. Gelatinase activity was increased in the lavage fluid from these lungs. These results suggest that in these mice TNF-alpha contributed to the development of pulmonary emphysema through chronic lung inflammation and activation of the elastolytic enzymes but by itself was unable to produce significant pulmonary fibrosis.

Expression of new idiotypes following neonatal idiotypic suppression of a dominant clone

The anti-PC antibodies of BALB/c origin bear predominantly the idiotype characteristic of the phosphorylcholine (PC)-binding T15 idiotype than sera from adult mice, and, unlike the latter, they also contain detectable amounts of anti-T15 antibodies. By 2 weeks of age the anti-T15 antibodies are no longer detectable while the T15 idiotype has reached adult levels. Injection of neonatal mice with anti-idiotypic antibodies renders them unresponsive to PC until the 15th week of life. Furthermore, this treatment induces a chronic suppression of the T15 idiotype, since on recovery from unresponsiveness, the neonatally suppressed mice produce anti-PC antibodies which are predominantly T15-negative. In contrast, treatment of adult mice with anti-idiotypic antibodies induces only a transient state of unresponsiveness to PC, and the antibodies produced upon recovery bear the T15 idiotype. These findings are discussed in the context of idiotype anti-idiotype interactions and their possible role in immuno-regulation.

Self heat shock and gamma delta T-cell reactivity

We have investigated the effects of heat shock on T-cell induction and selection in vitro. We find that when cell preparations containing T lymphocytes are incubated for 30 min at 42 degrees C, a selective proliferation of gamma delta + T cells bearing the gamma delta T-cell antigen receptor follows. A greater enrichment of gamma delta + T cells is observed, upon preexposure to mycobacterial antigens in vivo. By comparing the effects of heat shock with that of mitogen or specific T-cell triggering by conventional antigens and by analyzing the gamma delta T-cell receptor genes expressed in cells that proliferate as a result of heat shock induction, we conclude that a subset of murine gamma delta T cells react to antigens on self cells in which a heat shock response was induced.

Exploiting Heavier Organochalcogen Compounds in Donor-Acceptor Cyclopropane Chemistry

Donor-acceptor (D-A) cyclopropanes have gained increased momentum over the past two decades. The use of these highly strained three-membered entities paved the way to innovative and original transformations yielding complex cyclic and acyclic architectures that otherwise might be difficult to address. Since the fundamentals were laid by Wenkert and Reissig in the late 1970s, the field has flourished impressively including asymmetric transformations as well as elegant synthetic applications in the construction of natural occurring products. In this Account, we aim to highlight especially our efforts in the context of an efficient access to sulfur- and selenium-containing compounds, of either cyclic or open-chain nature, by exploiting D-A cyclopropane chemistry. Light will be shed on the three fundamental transformations: ring-opening reactions, cycloadditions, and rearrangements.Our synthetic endeavors started back in 2011 guided by quantum chemical studies to obtain 3,3'-linked bisthiophenes along with an unprecedented rearrangement delivering sulfur- and selenium-containing cagelike scaffolds. Inspired by these surprising results, we further deepened our efforts to the construction of new sulfur-carbon and selenium-carbon bonds within the context of D-A cyclopropane chemistry. In the first instance, we capitalized on the great versatility of organosulfur and organoselenium compounds regarding their amphiphilic character to act either as nucleophilic or as electrophilic species. By such an approach, ring-openings via a nucleophilic attack of sulfenyl and selenyl halides furnished 1,3-bishalochalcogenated products. A similar protocol led us to a desymmetrization reaction of meso-cyclopropyl carbaldehydes employing novel chiral imidazolidinone organocatalysts. In contrast, electrophilic sulfur was supplied by N-(arylthio)succinimide substrates to access thiolated γ-amino acid derivatives and their selenium equivalents.Combining the highly reactive thiocarbonyl compounds and vicinal donor-acceptor substituted cyclopropanes opened new vistas in the field of atom-economic cycloaddition reactions to build up sulfur-containing heterocycles of various sizes. The first systematic study of such transformations was made by our group in 2017 leading to highly decorated thiolanes, whereas an intramolecular approach furnished thia-[n.2.1]bicyclic ring systems. Our investigations were then successfully extended to the synthesis of tetrahydroselenophenes by using capricious selenoketones. Recently, we were able to yield the unsaturated analogues, selenophenes, by a (3 + 2)-cycloaddition of D-A cyclopropanes with ammonium selenocyanates followed by oxidation. The formal insertion of thioketenes was realized by employing 3-thioxocyclobutanones as surrogates for disubstituted thioketenes to obtain 2-substituted tetrahydrothiophenes bearing a semicyclic double bond via a (3 + 2) spiroannulation/(2 + 2) cycloreversion sequence. Even the formation of seven-membered S-heterocycles was realized by (4 + 3)-cycloaddition processes. In 2016, we demonstrated the synthesis of benzo-fused dithiepines from in situ generated ortho-bisthioquinones, whereas the utilization of thia-Michael systems as a hetero-4π-component delivered tetrahydrothiepine derivatives containing just one sulfur atom embedded in the ring system.

Vitamin A supplementation and increased prevalence of childhood diarrhoea and acute respiratory infections

There is uncertainty over whether vitamin A supplementation reduces morbidity among children with subclinical deficiency of the vitamin. Hence a double-blind, placebo-controlled trial of the effect of vitamin A supplementation on childhood morbidity was conducted among 11,124 children aged 6-83 months in the northwest of Haiti. After a random start, children were sequentially assigned by household units to receive either megadose vitamin A or placebo in three distribution cycles 4 months apart. 2 to 8 weeks after each administration of the vitamin A and placebo capsules, indicators of childhood morbidity were reassessed through interviews conducted in the homes of participating families. The vitamin A group was found to have an increased 2-week prevalence of all symptoms and signs of childhood morbidity assessed, including diarrhoea (rate ratio [RR] = 1.09, 95% confidence interval 1.05-1.14), rhinitis (RR = 1.02, 95% confidence interval 1.00-1.04), cold/flu symptoms (RR = 1.04, 95% confidence interval 1.01-1.06), cough (RR = 1.07, 95% confidence interval 1.03-1.11), and rapid breathing (RR = 1.18, 95% confidence interval 1.09-1.27). The study shows an increased 2-week prevalence of diarrhoea and the symptoms of respiratory infections after vitamin A supplementation.

Ring-Opening 1,3-Aminochalcogenation of Donor-Acceptor Cyclopropanes: A Three-Component Approach

A 1,3-aminothiolation was realized by reacting 2-substituted cyclopropane 1,1-dicarboxylates with sulfonamides and N-(arylthio)succinimides. Under Sn(OTf)2 catalysis the transformation proceeded smoothly to the corresponding ring-opened products bearing the sulfonamide in the 1-position next to the donor and the arylthio residue in the 3-position next to the acceptor. The procedure was extended to the corresponding selenium analogues by employing N-(phenylseleno)succinimides as an electrophilic selenium source.

Mechanism of cyclization of pyridine nucleotides by bovine spleen NAD+ glycohydrolase

We have shown that bovine spleen NAD+ glycohydrolase (EC), purified to homogeneity, is a multifunctional enzyme. A time-dependent formation of cADPR from NAD+ that did not exceed 1.5-2% of the reaction products was measurable. The cyclase activity of this enzyme was, however, best evidenced by its transformation of NGD+ into cyclic GDP-ribose (cGDPR). The formation of the cyclic compound could be monitored spectroscopically (UV and fluorescence) and by high-performance liquid chromatography; the product ratio of cGDPR/GDP-ribose was 2:1. Bovine spleen NAD+ glycohydrolase is also able to hydrolyze cADPR (Muller-Steffner et al. (1994) Biochem. Biophys. Res. Commun. 204, 1279-1285); the kinetic parameters (V/Km) measured exclude, however, the possibility that cADPR is a kinetically competent reaction intermediate in the transformation of NAD+ into ADP-ribose. Experimental data indicating that NAD+ glycohydrolase-catalyzed hydrolysis and methanolysis of NA(G)D+ occurred at the expense of the formation of the cyclic compounds are in favor of a reaction mechanism involving the partitioning of a common oxocarbenium reaction intermediate between the different acceptors. Thus E.A(G)DP-ribosyl oxocarbenium intermediate can react according to i) intramolecular processes with the positions N-1 of adenine and N-7 of guanine to give cA(G)DPR as reaction products, and ii) intermolecular reactions with water (formation of A(G)DP-ribose) and methanol (formation of methyl A(G)DP-ribose). We attribute the marked difference in yield of cADPR and cGDPR to the intrinsic reactivity (nucleophilicity and positioning) of the purine N-positions that are involved in the cyclization reactions within the E.A(G)DP-ribosyl oxocarbenium complexes.

Patients with Multiple Sclerosis and concomitant uveitis/periphlebitis retinae are not distinct from those without intraocular inflammation

Recent models of experimental autoimmune encephalomyelitis (EAE) have indicated that antigens co-expressed in the retina and uvea might be of pathogenetic relevance in Multiple Sclerosis (MS). We investigated the clinical spectrum and magnetic resonance imaging of 11 MS patients with concomitant uveitis, and determined the frequency of clinically silent intraocular inflammation in a prospective series of 50 patients. Two of the 11 patients had panuveitis, seven had anterior, and the remaining two had intermediate uveitis. The onset of uveitis preceded that of neurological symptoms by a mean of 8.5 years (range 1-20). None of the 50 MS patients studied prospectively by using slit lamp examinations and dilated funduscopy showed any evidence of uveitis but six patients had signs of retinal inflammation ("periphlebitis retinae"). Cranial MRI did not reveal "atypical" lesional distribution in MS patients with uveitis or periphlebitis retinae. No correlation between the type of MS and uveitis, or between the degree of neurological disability and the type of uveitis was found.

Analysis of tear proteins by one- and two-dimensional thin-layer iosoelectric focusing, sodium dodecyl sulfate electrophoresis and lectin blotting. Detection of a new component: cystatin C

BACKGROUND

Isoelectric focusing (IEF) of tear proteins has not yet been carried out in a satisfactory way. Two-dimensional (2D) electrophoresis, especially in the combination of IEF with SDS, is able to differentiate between proteins in detail. The purpose of this study was therefore to analyze tear proteins by 1D IEF alone and in combination with a 2D pattern, and by IEF followed by lectin staining.

METHODS

Ampholines, covering a broad range from pH 3 to pH 10, were applied. After IEF, semi-dry blotting and incubation with a group II lectin and two group V lectins was performed.

RESULTS

Tear proteins could be separated into 31 single bands. Tear-specific pre-albumin (TSPA), lactoferrin, sIgA, IgG and lysozyme were found to be main components. Isoelectric points (IEPs, pls) of all proteins separated were determined by comparison with IEF standards. 2D patterns of IEF and SDS electrophoresis were obtained for the main subunit components of lactoferrin, sIgA, TSPA, and lysozyme. An additional new component of considerable concentration was focused at pI 8.6 with a subunit MW of 14 kDa. With s-WGA a component at an IEP of 5.2 was visualized, representing transferrin. With SNA, lactoferrin stained as a sharp main band at pI 5.1 with three additional weaker bands at IEPs from 4.8 to 4.9. At IEPs between 4.4 and 6.1, multiple components of sIgA were stained with MAA. The sugar specificity of transferrin at pI 5.2 was beta-GlcNAc. Lactoferrin showed glycation with NANA-alpha-2-6-Gal or NANA-alpha-2-6-GalNAc, whereas the sugar specificity of sIgA was NANA-alpha-2-3-Gal.

CONCLUSIONS

The investigative strategy applied here, including IEF alone, in combination with SDS-electrophoresis, and SDS-electrophoresis followed by lectin staining proved to be a reproducible method for tear protein analysis of hitherto unexperienced capacity. Lectin-stained bands of native tear proteins are not uniformly glycated by one sugar residue, but show various sugar specificities. IgA as a whole molecule is specifically glycated with NANA-alpha-2-3-Gal.

Homing and in situ differentiation of resident pulmonary lymphocytes

At birth, T lymphocytes which colonize the lung are mainly of the gamma delta subset, while alpha beta T cells predominate in the spleen. Thus, the lung is a preferred site for the homing of gamma delta T cells in the perinatal period. However, after birth, the pattern of V gamma gene usage among resident pulmonary lymphocytes (RPL) changes with age, from a predominance of V gamma 6 at birth to a predominance of V gamma 4 in older mice. The generation of the V gamma 6 fraction appears to be thymus dependent, since in athymic nude mice, the V gamma 6 population present at birth is replaced by V gamma 4 T cells. In the postnatal period, both RAG-1 and RAG-2 genes are expressed at high levels in the RPL population. TCR bearing cells are among those that express RAG genes, indicating that maturation of T cells takes place in this organ. In addition, transfer experiments reveal that lymphoid precursors are present in the lung. The stage of differentiation of these precursors will be characterized in future studies. The data presented here indicate that pulmonary T lymphocytes are derived from both migrants of thymic origin and from precursors which have undergone differentiation and selection in the lung. The population that is generated in situ and that has not been selected in the thymus may include cells that are typical for the pulmonary environment.

Protic Ionic Liquid as Reagent, Catalyst, and Solvent: 1-Methylimidazolium Thiocyanate

We propose a new concept of the triple role of protic ionic liquids with nucleophilic anions: a) a regenerable solvent, b) a Brønsted acid inducing diverse transformations via general acid catalysis, and c) a source of a nucleophile. The efficiency of this strategy was demonstrated using thiocyanate-based protic ionic liquids for the ring-opening of donor-acceptor cyclopropanes. A wide variety of activated cyclopropanes were found to react with 1-methylimidazolium thiocyanate under mild metal-free conditions via unusual nitrogen attack of the ambident thiocyanate ion on the electrophilic center of the three-membered ring affording pyrrolidine-2-thiones bearing donor and acceptor substituents at the C(5) and C(3) atoms, respectively, in a single time-efficient step. The ability of 1-methylimidazolium thiocyanate to serve as a triplex reagent was exemplarily illustrated by (4+2)-annulation with 1-acyl-2-(2-hydroxyphenyl)cyclopropane, epoxide ring-opening and other organic transformations.

Dominantly inherited expression of BID, an invariant undiversified T cell receptor delta chain

In BALB/c lung and lymph node gamma delta T cells, a large fraction of the expressed V delta 5 genes consist of an invariant sequence, BID (for BALB/c invariant delta). BID results from a direct joining of the V delta 5, D delta 2, and J delta 1 segments, which conserve their complete germline coding sequences. In C57BL/6 (H-2b) mice, where identical and functional segments are present in the germline, BID is absent. It appears that BID+ gamma delta T cells are positively selected by factors encoded outside of the classical MHC region, as indicated by their dominance in F1(C57BL/6 x BALB/c) and in BALB.B (H-2b) mice. Additional observations, including the expression of BID in BALB/c nu/nu but not in C57BL/6 nu/nu mice, suggest that the expansion of BID+ T cells essentially occurs extrathymically.

Cycloadditions of Donor-Acceptor Cyclopropanes and -butanes using S=N-Containing Reagents: Access to Cyclic Sulfinamides, Sulfonamides, and Sulfinamidines

We present (3+2)- and (4+2)-cycloadditions of donor-acceptor (D-A) cyclopropanes and cyclobutanes with N-sulfinylamines and a sulfur diimide, along with a one-pot, two-step strategy for the formal insertion of HNSO2 into D-A cyclopropanes. These are rare examples of cycloadditions with D-A cyclopropanes and cyclobutanes whereby the 2π component consists of two different heteroatoms, thus leading to five- and six-membered rings containing adjacent heteroatoms.

Chromosomal mapping in the mouse of eight K(+)-channel genes representing the four Shaker-like subfamilies Shaker, Shab, Shaw, and Shal

The four Shaker-like subfamilies of Shaker-, Shab-, Shaw-, and Shal-related K+ channels in mammals have been defined on the basis of their sequence homologies to the corresponding Drosophila genes. Using interspecific backcrosses between Mus musculus and Mus spretus, we have chromosomally mapped in the mouse the Shaker-related K(+)-channel genes Kcna1, Kcna2, Kcna4, Kcna5, and Kcna6; the Shab-related gene Kcnb1; the Shaw-related gene Kcnc4; and the Shal-related gene Kcnd2. The following localizations were determined: Chr 2, cen-Acra-Kcna4-Pax-6-a-Pck-1-Kras-3-Kcn b1 (corresponding human Chrs 11p and 20q, respectively); Chr 3, cen-Hao-2-(Kcna2, Kcnc4)-Amy-1 (human Chr 1); and Chr 6, cen-Cola-2-Met-Kcnd2-Cpa-Tcrb-adr/Clc-1-Hox-1.1-Myk - 103-Raf-1-(Tpi-1, Kcna1, Kcna5, Kcna6) (human Chrs 7q and 12p, respectively). Thus, there is a cluster of at least three Shaker-related K(+)-channel genes on distal mouse Chr 6 and a cluster on Chr 2 that at least consists of one Shaker-related and one Shaw-related gene. The three other K(+)-channel genes are not linked to each other. The map positions of the different types of K(+)-channel genes in the mouse are discussed in relation to those of their homologs in man and to hereditary diseases of mouse and man that might involve K+ channels.

Glypican-2 levels in cerebrospinal fluid predict the status of adult hippocampal neurogenesis

Adult hippocampal neurogenesis is a remarkable form of brain plasticity through which new neurons are generated throughout life. Despite its important roles in cognition and emotion and its modulation in various preclinical disease models, the functional importance of adult hippocampal neurogenesis in human health has not been revealed because of a lack of tools for monitoring adult neurogenesis in vivo. Therefore, we performed an unbiased proteomics screen to identify novel proteins expressed during neuronal differentiation using a human neural stem cell model, and we identified the proteoglycan Glypican-2 (Gpc2) as a putative secreted marker of immature neurons. Exogenous Gpc2 binds to FGF2 and inhibits FGF2-induced neural progenitor cell proliferation. Gpc2 is enriched in neurogenic regions of the adult brain. Its expression is increased by physiological stimuli that increase hippocampal neurogenesis and decreased in transgenic models in which neurogenesis is selectively ablated. Changes in neurogenesis also result in changes in Gpc2 protein level in cerebrospinal fluid (CSF). Gpc2 is detectable in adult human CSF, and first pilot experiments with a longitudinal cohort indicate a decrease over time. Thus, Gpc2 may serve as a potential marker to monitor adult neurogenesis in both animal and human physiology and disease, warranting future studies.