Turn structures in CGRP C-terminal analogues promote stable arrangements of key residue side chains

The 37-amino acid calcitonin gene-related peptide (CGRP) is a potent endogenous vasodilator thought to be implicated in the genesis of migraine attack. CGRP antagonists may thus have therapeutic value for the treatment of migraine. The CGRP C-terminally derived peptide [D(31),P(34),F(35)]CGRP(27-37)-NH(2) was recently identified as a high-affinity hCGRP(1) receptor selective antagonist. Reasonable CGRP(1) affinity has also been demonstrated for several related analogues, including [D(31),A(34),F(35)]CGRP(27-37)-NH(2). In the study presented here, conformational and structural features in CGRP(27-37)-NH(2) analogues that are important for hCGRP(1) receptor binding were explored. Structure-activity studies carried out on [D(31),P(34),F(35)]CGRP(27-37)-NH(2) resulted in [D(31),P(34),F(35)]CGRP(30-37)-NH(2), the shortest reported CGRP C-terminal peptide analogue exhibiting reasonable hCGRP(1) receptor affinity (K(i) = 29.6 nM). Further removal of T(30) from the peptide's N-terminus greatly reduced receptor affinity from the nanomolar to micromolar range. Additional residues deemed critical for hCGRP(1) receptor binding were identified from an alanine scan of [A(34),F(35)]CGRP(28-37)-NH(2) and included V(32) and F(37). Replacement of the C-terminal amide in this same peptide with a carboxyl, furthermore, resulted in a greater than 50-fold reduction in hCGRP(1) affinity, thus suggesting a direct role for the amide moiety in receptor binding. The conformational properties of two classes of CGRP(27-37)-NH(2) peptides, [D(31),X(34),F(35)]CGRP(27-37)-NH(2) (X is A or P), were examined by NMR spectroscopy and molecular modeling. A beta-turn centered on P(29) was a notable feature consistently observed among active peptides in both series. This turn led to exposure of the critical T(30) residue to the surrounding environment. Peptides in the A(34) series were additionally characterized by a stable C-terminal helical turn that resulted in the three important residues (T(30), V(32), and F(37)) adopting consistent interspatial positions with respect to one another. Peptides in the P(34) series were comparatively more flexible at the C-terminus, although a large proportion of the [D(31),P(34),F(35)]CGRP(27-37)-NH(2) calculated conformers contained a gamma-turn centered on P(34). These results collectively suggest that turn structures at both the C-terminus and N-terminus of CGRP(27-37)-NH(2) analogues may help to appropriately orient critical residues (T(30), V(32), and F(37)) for hCGRP(1) receptor binding.

The experimental herbicide CGA 325'615 inhibits synthesis of crystalline cellulose and causes accumulation of non-crystalline beta-1,4-glucan associated with CesA protein

Developing cotton (Gossypium hirsutum) fibers, cultured in vitro with their associated ovules, were used to compare the effects of two herbicides that inhibit cellulose synthesis: 2,6-dichlorobenzonitrile (DCB) and an experimental thiatriazine-based herbicide, CGA 325'615. CGA 325'615 in nanomolar concentrations or DCB in micromolar concentrations causes inhibition of synthesis of crystalline cellulose. Unlike DCB, CGA 325'615 also causes concomitant accumulation of non-crystalline beta-1,4-glucan that can be at least partially solubilized from fiber walls with ammonium oxalate. The unusual solubility of this accumulated glucan may be explained by its strong association with protein. Treatment of the glucan fraction with protease changes its size distribution and leads to precipitation of the glucan. Treatment of the glucan fraction with cellulase digests the glucan and also releases protein that has been characterized as GhCesA-1 and GhCesA-2--proteins that are believed to represent the catalytic subunit of cellulose synthase. The fact that cellulase treatment is required to release this protein indicates an extremely tight association of the glucan with the CesA proteins. In addition, CGA 325'615, but not DCB, also causes accumulation of CesA protein and a membrane-associated cellulase in the membrane fraction of fibers. In addition to the effects of CGA 325'615 on levels of both of these proteins, the level of both also shows coordinate regulation during fiber development, further suggesting they are both important for cellulose synthesis. The accumulation of non-crystalline glucan caused by CGA 325'615 mimics the phenotype of the cellulose-deficient rsw1 mutant of Arabidopsis that also accumulates an apparently similar glucan (T. Arioli, L. Peng, A.S. Betzner, J. Burn, W. Wittke, W. Herth, C. Camilleri, H. Hofte, J. Plazinski, R. Birch et al. [1998] Science 279: 717).

First-trimester prenatal diagnosis of a familial subtelomeric translocation

A new fluorescent in situ hybridization (FISH) technique utilizes a complete set of telomeric probes to screen for deletions or rearrangements within the subtelomeric regions of all chromosomes on a single slide. Such cryptic chromosome rearrangements would otherwise remain undetected by standard cytogenetic analysis. In this case report, we describe the first-trimester prenatal diagnosis of an unbalanced rearrangement in a family where such a cryptic subtelomeric rearrangement is segregating. Interestingly the fetus was also noted to have an increased nuchal translucency at the time first-trimester chorionic villus sampling was performed and a FISH diagnosis made. The result was subsequently confirmed on fetal material obtained after elective termination of the pregnancy. We believe this to be the first report in the literature (as by Medline, December 1999) of a first-trimester prenatal diagnosis using such subtelomeric probes where confirmation by conventional cytogenetic analysis was not possible.

A new locus for autosomal dominant familial exudative vitreoretinopathy maps to chromosome 11p12-13

We report a new locus for familial exudative vitreoretinopathy (FEVR), on chromosome 11p12-13 in a large autosomal dominant pedigree. Statistically significant linkage was achieved across a 14-cM interval flanked by markers GATA34E08 and D11S4102, with a maximum multipoint LOD score of 6.6 at D11S2010. FEVR is a disease characterized by the failure of development of peripheral retinal blood vessels, and it is difficult to diagnose clinically because of the wide spectrum of fundus abnormalities associated with it. The identification of a new locus is important for genetic counseling and potentiates further studies aimed toward the identification of a gene with an important role in angiogenesis within neuroepithelial tissues. Such a gene may also have a role in the genetic predisposition to retinopathy of prematurity, a sporadic disorder with many clinical similarities to FEVR.

Growth and change in the prescribing of anti-depressants in New Zealand: 1993-1997

AIMS

To examine changes in the prescribing of anti-depressants in New Zealand from 1993-1997, in terms of expenditure, the number of dispensings and days of therapy supplied.

METHOD

Data on subsidised dispensings of anti-depressant drugs during 1993 to 1997 were obtained from PHARMAC and analysed using SAS.

RESULTS

The overall size of the anti-depressant market increased considerably over the study period. Government expenditure rose 2.25 times, and 1.65 times as many days of anti-depressant medication were supplied in 1997 as in 1993. Most of this was due to the growth in prescribing of newer anti-depressants, but the use of older drugs remained constant.

CONCLUSIONS

In common with other countries, the use of newer agents is contributing to increased overall use of anti-depressant medication and government expenditure in New Zealand. Use of older drugs has not diminished substantially.

Regional variation in anti-depressant dispensings in New Zealand: 1993-1997

AIMS

To examine regional differences in the prescribing of anti-depressants in New Zealand from 1993 to 1997, and to examine the composition and dynamics of these differences.

METHODS

Data on every subsidised dispensing of anti-depressant drugs 1993 to 1997 were obtained from PHARMAC and analysed using SAS. Each dispensing was allocated to a regional council area on the basis of the location of the dispensing pharmacy.

RESULTS

Prescribing of anti-depressants increased with time in all regions. However, there was substantial regional variation in prescribing rates per-capita, the highest being 2.28 to 2.49 times the lowest in every year. Regions also varied substantially in the mix of newer and older drugs used, although newer drugs became increasingly important in every region.

CONCLUSIONS

Regional differences in anti-depressant prescribing are large. Further research with different data sources is required to explore the reasons for this variation.

Human hepatocyte cell lines proliferating as cohesive spheroid colonies in alginate markedly upregulate both synthetic and detoxificatory liver function

BACKGROUND/AIMS

Bio-artificial liver support systems for treatment of hepatic failure require maintained expression of hepatocyte function in vitro. We studied cultures of human hepatocyte cell-lines proliferating within alginate beads, investigating the hypothesis that 3-dimensional cohesive colonies of hepatocyte cell-lines would achieve polarity and cell-to-cell contact resulting in upregulation of function.

METHODS

HepG2 and HHY41 human cell lines in alginate beads were cultured for >20 days.

RESULTS

Proliferation was maintained for 20 days. Production of albumin, prothrombin, fibrinogen, alpha-1-acid glycoprotein and alpha-1-antitrypsin was maintained throughout, maximal at days 8-10, when upregulation was 300-1100% compared with monolayer cultures at similar cell number per unit volume. Detoxificatory functions: ethoxyresorufin deethylase activity, androstenedione metabolism, and urea synthesis from arginine was also increased several-fold. Function returned to pre-freezing levels within 18 h of thawing after cryopreservation of cells in alginate. Electron microscopy revealed spherical colonies of cells of cuboidal shape, with cell-to-cell contact via desmosomes and junctional complexes, abundant microvilli, and cytoplasmic appearances suggesting transcriptionally active hepatocytes.

CONCLUSION

Hepatocyte cell-lines, proliferating in alginate express a range of liver-specific functions at levels approaching those found in vivo, relevant to their use in liver support systems.

A fifth locus for primary autosomal recessive microcephaly maps to chromosome 1q31

Primary microcephaly is a genetic disorder in which an affected individual has a head circumference >3 SDs below the age- and sex-related mean. A small but apparently normally formed brain is the reason for the reduced head circumference, and, probably because of this, all affected individuals are mentally retarded. The condition is genetically heterogeneous, and four loci have already been identified. We now report a fifth locus, MCPH5, which is an 8-cM region mapping to chromosome 1q31, defined by the markers GATA135F02 and D1S1678.

A new locus for autosomal recessive non-syndromal sensorineural hearing impairment (DFNB27) on chromosome 2q23-q31

Non-syndromic sensorineural deafness is an extremely genetically heterogeneous condition. We have used autozygosity mapping in a large consanguineous United Arab Emirate family to identify a novel locus for autosomal recessive non-syndromic sensorineural deafness, DFNB27, on chromosome 2q23-q31, with a maximum two-point lod score of 5.18 at theta = 0 for marker D2S2257. The DFNB27 locus extends over a 17 cM region between D2S2157 and D2S2273, and may overlap the DFNA16 locus for dominantly inherited, fluctuating, progressive non-syndromal hearing loss. However, genotype data suggests that the locus is likely to be refined to between D2S326 and D2S2273 and thus distinct from the DFNA16 locus.

N,N-Diethyl-4-(phenylpiperidin-4-ylidenemethyl)benzamide: a novel, exceptionally selective, potent delta opioid receptor agonist with oral bioavailability and its analogues

The design, synthesis, and pharmacological evaluation of a novel class of delta opioid receptor agonists, N, N-diethyl-4-(phenylpiperidin-4-ylidenemethyl)benzamide (6a) and its analogues, are described. These compounds, formally derived from SNC-80 (2) by replacing the piperazine ring with a piperidine ring containing an exocyclic carbon carbon double bond, were found to bind with high affinity and exhibit excellent selectivity for the delta opioid receptor as full agonists. 6a, the simplest structure in the class, exhibited an IC(50) = 0.87 nM for the delta opioid receptors and extremely high selectivity over the mu receptors (mu/delta = 4370) and the kappa receptors (kappa/delta = 8590). Rat liver microsome studies on a selected number of compounds show these olefinic piperidine compounds (6) to be considerably more stable than SNC-80. This novel series of compounds appear to interact with delta opioid receptors in a similar way to SNC-80 since they demonstrate similar SAR. Two general approaches have been established for the synthesis of these compounds, based on dehydration of benzhydryl alcohols (7) and Suzuki coupling reactions of vinyl bromide (8), and are herewith reported.

New diarylmethylpiperazines as potent and selective nonpeptidic delta opioid receptor agonists with increased In vitro metabolic stability

Nonpeptide delta opioid agonists are analgesics with a potentially improved side-effect and abuse liability profile, compared to classical opioids. Andrews analysis of the NIH nonpeptide lead SNC-80 suggested the removal of substituents not predicted to contribute to binding. This approach led to a simplified lead, N, N-diethyl-4-[phenyl(1-piperazinyl)methyl]benzamide (1), which retained potent binding affinity and selectivity to the human delta receptor (IC(50) = 11 nM, mu/delta = 740, kappa/delta > 900) and potency as a full agonist (EC(50) = 36 nM) but had a markedly reduced molecular weight, only one chiral center, and increased in vitro metabolic stability. From this lead, the key pharmacophore groups for delta receptor affinity and activation were more clearly defined by SAR and mutagenesis studies. Further structural modifications on the basis of 1 confirmed the importance of the N, N-diethylbenzamide group and the piperazine lower basic nitrogen for delta binding, in agreement with mutagenesis data. A number of piperazine N-alkyl substituents were tolerated. In contrast, modifications of the phenyl group led to the discovery of a series of diarylmethylpiperazines exemplified by N, N-diethyl-4-[1-piperazinyl(8-quinolinyl)methyl]benzamide (56) which had an improved in vitro binding profile (IC(50) = 0.5 nM, mu/delta = 1239, EC(50) = 3.6 nM) and increased in vitro metabolic stability compared to SNC-80.

Allograft rejection results from a failed attempt by the immune system to protect foreign tissue

The focus of our research is to understand the immune response to foreign tissue. We believe that a dichotomy exists within the immune response to an allograft such that part of the response is dedicated to the protection of the graft. Nevertheless, in a dominantly graft-aggressive environment, rejection typically ensues. In this article, we describe models that have been set up to test directly the ability of potentially protective aspects of the immune response to prevent allograft rejection. We discuss our data in the context of a growing body of exciting and often controversial literature.

Randomized trial of a specialist genetic assessment service for familial breast cancer

BACKGROUND

Because of the growing demand for genetic assessment, there is an urgent need for information about what services are appropriate for women with a family history of breast cancer. Our purpose was to compare the psychologic impact and costs of a multidisciplinary genetic and surgical assessment service with those of current service provisions.

METHODS

We carried out a prospective randomized trial of surgical consultation with (the trial group) and without (the control group) genetic assessment in 1000 women with a family history of breast cancer. All P: values are from two-sided tests.

RESULTS

Although statistically significantly greater improvement in knowledge about breast cancer was found in the trial group (P: =.05), differences between groups in other psychologic outcomes were not statistically significant. Women in both groups experienced statistically significant reductions in anxiety and found attending the clinics to be highly satisfying. An initial specialist genetic assessment cost pound 14.27 (U.S. $22.55) more than a consultation with a breast surgeon. Counseling and genetic testing of affected relatives, plus subsequent testing of family members of affected relatives identified as mutation carriers, raised the total extra direct and indirect costs per woman in the trial group to pound 60.98 (U.S. $96.35) over costs for the control subjects.

CONCLUSIONS

There may be little benefit in providing specialist genetics services to all women with a family history of breast cancer. Further investigation of factors that may mediate the impact of genetic assessment is in progress and may reveal subgroups of women who would benefit from specialist genetics services.

Aicardi-Goutières syndrome displays genetic heterogeneity with one locus (AGS1) on chromosome 3p21

We have studied 23 children from 13 families with a clinical diagnosis of Aicardi-Goutières syndrome. Affected individuals had developed an early-onset progressive encephalopathy that was characterized by a normal head circumference at birth, basal ganglia calcification, negative viral studies, and abnormalities of cerebrospinal fluid comprising either raised white cell counts and/or raised levels of interferon-alpha. By means of genomewide linkage analysis, a maximum-heterogeneity LOD score of 5.28 was reached at marker D3S3563, with alpha=.48, where alpha is the proportion of families showing linkage. Our data suggest the existence of locus heterogeneity in Aicardi-Goutières syndrome and highlight potential difficulties in the differentiation of this condition from pseudo-TORCH (toxoplasmosis, rubella, cytomegalovirus, and herpes simplex virus types 1 and 2) syndrome.

The endothelium and cytokine secretion: the role of peroxidases as immunoregulators

The endothelium is frequently exposed to many proinflammatory mediators. The present study was done to determine the effects of human recombinant myeloperoxidase (MPO) and porcine eosinophil peroxidase (EPO) on certain endothelial cell (HUVEC) functions. The following areas were evaluated: (1) production of reactive oxygen intermediates (ROI), (2) cytokine secretion, and (3) regulation of mRNA cytokine transcripts. Both MPO and EPO induced the production of ROI, but an enzymatically inactive form of MPO (iMPO) was the most effective. Enzymatically inactive MPO, but not MPO, induced the secretion of interleukins 6 and 8 and granulocyte-monocyte colony-stimulating factor. A ribonuclease protection assay indicated that both iMPO and MPO upregulated mRNA cytokine transcripts; however, the former was markedly more effective. The simultaneous addition of EPO and iMPO resulted in a decrease in cytokine-specific mRNA. These data indicate a major role for peroxidases in the regulation of inflammation.

Effects of a glyconutrient on macrophage functions

Previous studies have shown that mannosylated bovine serum albumin (mBSA) enhances the respiratory burst (RB), phagocytosis, and killing of Candida albicans and Escherichia coli by resident murine peritoneal macrophages (Mphi). Upregulation of the above Mphi functions was associated with the binding of mBSA to the macrophage mannose receptor. The present study was done to determine if certain glyconutrients could stimulate Mphi functions in a similar manner. Resident peritoneal murine Mphi collected from C57BL/6 mice were exposed to the glyconutrients for 10 and 60 min. The RB was measured using chemiluminescence. Both phagocytosis and killing were measured after incubation with each of the following microorganisms: Candida albicans, Escherichia coli and Staphylococcus aureus. The percent phagocytosis and killing were determined using fluorescence microscopy. Results indicated that certain glyconutrients, caused a dose and time dependent effect on Mphi-induced killing of all three microorganisms.

A model protocol evaluating the introduction of genetic assessment for women with a family history of breast cancer

Randomised controlled trials allow comparisons to be made between different models of service delivery, but have not been used in the field of clinical genetics. With the advent of clinical governance, the evidence provided by such trials will be increasingly important in informing and shaping clinical genetics practice. The TRACE project (Trial of genetic assessment in breast cancer) is a randomised controlled trial of genetic assessment for women who are at increased risk of breast cancer because of their family history. The absence of cancer genetics service provision in Wales before this study gave a window of opportunity in which this important trial could be conducted. The present paper describes how TRACE will provide crucial evidence regarding the psychosocial as well as resource implications of adding individualised genetic assessment, genetic counselling, and (where appropriate) gene testing to typical advice and surveillance from a hospital breast clinic. In addition, it is anticipated that TRACE will represent a model for future trials of service delivery in the increasing number of complex genetic disorders where evidence on the economic implications of screening and management is currently limited.

Elderly people. Old testament

Primary care groups need to address the needs of elderly people. Elderly people and their carers should be consulted about services. Elderly service users can be enthusiastic participants in consultation initiatives.

A third novel locus for primary autosomal recessive microcephaly maps to chromosome 9q34

Primary autosomal recessive microcephaly is a clinical diagnosis of exclusion in an individual with a head circumference >/=4 SDs below the expected age-and-sex mean. There is associated moderate mental retardation, and neuroimaging shows a small but structurally normal cerebral cortex. The inheritance pattern in the majority of cases is considered to be autosomal recessive. Although genetic heterogeneity for this clinical phenotype had been expected, this has only recently been demonstrated, with the mapping of two loci for autosomal recessive primary microcephaly: MCPH1 at 8p and MCPH2 at 19q. We have studied a large multiaffected consanguineous pedigree, using a whole-genome search, and have identified a third locus, MCPH3 at 9q34. The minimal critical region is approximately 12 cM, being defined by the markers cen-D9S1872-D9S159-tel, with a maximum two-point LOD score of 3.76 (recombination fraction 0) observed for the marker D9S290.

Increased dendritic MAP2 expression in the hippocampus in schizophrenia

Microtubule associated proteins (MAPs) are central to the development of normal neuronal cytoarchitecture and have been reported to be altered in schizophrenia. In 12 schizophrenic (DSM-III-R criteria) and 12 control hippocampi, we estimated the MAP2 immunoreactive dendritic length using antibodies that recognize total MAP2 (MAP2-T), and a non-phosphorylated form of MAP2 (MAP2-NP). Within the corona ammonis (CA) subregions, and the subiculum, we estimated, for each antibody, the length of the immunoreactive dendritic arborisation using a stereological length estimation technique based on Bouffon's Needle principle and image analysis computer software. Controlling for the confounding effects of age and post-mortem delay, we have found an elevation in overall MAP2-NP immunoreactive dendritic length among schizophrenic subjects in the CA3 (F=5.9, p=0.03), CA2 (F=6.5, p=0.02), CA1 (F=8.3, p=0.01) and subicular (F=9.5, p=0.008) hippocampal subregions. Similar analyses of MAP2-T immunoreactive dendritic length demonstrated significant elevations in the CA1 (F=8.3, p=0.02), CA4 (F=4.9, p=0.04) and subicular (F=7.4, p=0.01) regions. The findings of this quantitative study of increased MAP2 immunoreactive dendritic arborisation in schizophrenia are most likely to reflect either an altered dendritic arborisation or a generalised increase in levels of MAP2 with the hippocampal pyramidal neurons. These findings add to the growing literature indicating the presence of synaptodendritic abnormalities in schizophrenia.

Loss-of-function mutations in the cathepsin C gene result in periodontal disease and palmoplantar keratosis

Papillon-Lefèvre syndrome, or keratosis palmoplantaris with periodontopathia (PLS, MIM 245000), is an autosomal recessive disorder that is mainly ascertained by dentists because of the severe periodontitis that afflicts patients. Both the deciduous and permanent dentitions are affected, resulting in premature tooth loss. Palmoplantar keratosis, varying from mild psoriasiform scaly skin to overt hyperkeratosis, typically develops within the first three years of life. Keratosis also affects other sites such as elbows and knees. Most PLS patients display both periodontitis and hyperkeratosis. Some patients have only palmoplantar keratosis or periodontitis, and in rare individuals the periodontitis is mild and of late onset. The PLS locus has been mapped to chromosome 11q14-q21 (refs 7, 8, 9). Using homozygosity mapping in eight small consanguineous families, we have narrowed the candidate region to a 1.2-cM interval between D11S4082 and D11S931. The gene (CTSC) encoding the lysosomal protease cathepsin C (or dipeptidyl aminopeptidase I) lies within this interval. We defined the genomic structure of CTSC and found mutations in all eight families. In two of these families we used a functional assay to demonstrate an almost total loss of cathepsin C activity in PLS patients and reduced activity in obligate carriers.