The effect of topical adrenergic and anticholinergic agents on the choroidal thickness of young healthy adults

The human choroid is capable of rapidly changing its thickness in response to a variety of stimuli. However little is known about the role of the autonomic nervous system in the regulation of the thickness of the choroid. Therefore, we investigated the effect of topical parasympatholytic and sympathomimetic agents upon the choroidal thickness and ocular biometrics of young healthy adult subjects. Fourteen subjects (mean age 27.9 ± 4 years) participated in this randomized, single-masked, placebo-controlled study. Each subject had measurements of choroidal thickness (ChT) and ocular biometrics of their right eye taken before, and then 30 and 60 min following the administration of topical pharmacological agents. Three different drugs: 2% homatropine hydrobromide, 2.5% phenylephrine hydrochloride and a placebo (0.3% hydroxypropyl methylcellulose) were tested in all subjects; each on different days (at the same time of the day) in randomized order. Participants were masked to the pharmacological agent being used at each testing session. The instillation of 2% homatropine resulted in a small but significant increase in subfoveal ChT at 30 and 60 min after drug instillation (mean change 7 ± 3 μm and 14 ± 2 μm respectively; both p < 0.0001). The parafoveal choroid also exhibited a similar magnitude, significant increase in thickness with time after 2% homatropine (p < 0.001), with a mean change of 7 ± 0.3 μm and 13 ± 1 μm (in the region located 0.5 mm from the fovea center), 6 ± 1 μm and 12.5 ± 1 μm (1 mm from the fovea center) and 6 ± 2 μm and 12 ± 2 μm (1.5 mm from the fovea center) after 30 and 60 min respectively. Axial length decreased significantly 60 min after homatropine (p < 0.01). There were also significant changes in lens thickness (LT) and anterior chamber depth (ACD) (p < 0.05) associated with homatropine instillation. No significant changes in choroidal thickness, or ocular biometrics were found after 2.5% phenylephrine or placebo at any examination points (p > 0.05). In human subjects, significant increases in subfoveal and parafoveal choroidal thickness occurred after administration of 2% homatropine and this implies an involvement of the parasympathetic system in the control of choroidal thickness in humans.

Study of the novel non-xanthine heterocyclic compound GU 285 as a potent non-selective adenosine receptor antagonist in the rat

The novel pyrazolo[3,4-d]pyrimidine compound GU285 (4-amino-6-alpha-carbamoylethylthio-1- phenylpyrazolo[3,4-d]pyrimidine, CAS 134896-40-5) was examined for its ability (1) to inhibit binding of adenosine (ADO) receptor ligands in rat brain membranes, (2) to antagonise functional responses to ADO agonists in rat right and left atria and coronary resistance vessels, and (3) to reduce the fall in heart rate and arterial blood pressure produced by the ADO A1 agonist N6-cyclopentyladenosine (CPA) in the intact, anaesthetized rat. GU285 competitively inhibited binding of the ADO A1 agonist [3H]-R-N6-phenylisopropyladenosine (R-PIA) yielding a Ki value of 11 (7-18) nmol.l-1 (geometric mean +/- 95% Cl). When assayed against the ADO A2A selective agonist [3H]-2-[p-(2-carboxyethyl)- phenethylamino]-5'-N-ethylcarboxamidoadenosine, (CGS21680), a Ki of 15 (10-24) nmol.l-1 was obtained. In spontaneously beating right atria, GU285 competitively antagonized negative chronotropic effects of R-PIA with a pA2 of 8.7 +/- 0.3 and in electrically paced left atria, GU285 competitively antagonized negative inotropic effects of R-PIA with a pA2 of 9.0 +/- 0.1. In the potassium-arrested, perfused rat heart GU285 (1 mumol.l-1) antagonized only the high sensitivity, ADO A2B mediated component of the biphasic relaxation of the coronary vasculature produced by NECA. The low sensitivity component was unchanged. GU285 (1 mumol.kg-1) antagonized the negative chronotropic and hypotensive effects of the adenosine A1 agonist CPA in anaesthetized rats, producing a 10-fold rightward shift in the dose-response relationship. These data demonstrate that in the rat, GU285 is a potent, non-selective adenosine receptor antagonist that maintains its activity in vivo.

A linkage study across the T cell receptor A and T cell receptor B loci in families with rheumatoid arthritis

Objective. To examine whether the T cell receptor (TCR) A or TCRB loci exhibit linkage with disease in multiplex rheumatoid arthritis (RA) families. Methods. A linkage study was performed in 184 RA families from the UK Arthritis and Rheumatism Council Repository, each containing at least 1 affected sibpair. The microsatellites D14S50, TCRA, and D14S64 spanning the TCRA locus and D7S509, Vβ6.7, and D7S688 spanning the TCRB locus were used as DNA markers. The subjects were genotyped using a semiautomated polymerase chain reaction-based method. Two-point and multipoint linkage analyses were performed. Results. Nonparametric single-marker likelihood odds (LOD) scores were 0.49 (P = 0.07) for D14S50, 0.65 (P = 0.04) for TCRA, 0.07 (P = 0.29) for D14S64, 0.01 (P = 0.43) for D7S509, 0.0 (P = 0.50) for Vβ6.7, and 0.0 (P = 0.50) for D7S688. By multipoint analysis, there was no evidence of linkage at TCRB (LOD score 0), and the maximum LOD score at the TCRA locus was 0.37 (at D14S50). The presence of a susceptibility locus (LOD score < -2.0) was excluded, with lambda ≤ 1.8 at TCRA and ≤1.4 at TCRB. Conclusion. These linkage studies provide no significant evidence of a major germline-encoded TCRA or TCRB component of susceptibility to RA.

Estrogen receptor α regulates area-adjusted bone mineral content in late pubertal girls

Context: Whether the action of estrogen in skeletal development depends on estrogen receptor α as encoded by the ESR1 gene is unknown. Objectives: The aim of this study was to establish whether the gain in area-adjusted bone mineral content (ABMC) in girls occurs in late puberty and to examine whether the magnitude of this gain is related to ESR1 polymorphisms. Design: We conducted a cross-sectional analysis. Setting: The study involved the Avon Longitudinal Study of Parents and Children (ALSPAC), a population-based prospective study. Participants: Participants included 3097 11-yr-olds with DNA samples, dual x-ray absorptiometry measurements, and pubertal stage information. Outcomes: Outcome measures included separate prespecified analyses in boys and girls of the relationship between ABMC derived from total body dual x-ray absorptiometry scans and Tanner stage and of the interaction between ABMC, Tanner stage, and ESR1 polymorphisms. Results: Total body less head and spinal ABMC were higher in girls in Tanner stages 4 and 5, compared with those in Tanner stages 1, 2, and 3. In contrast, height increased throughout puberty. No differences were observed in ABMC according to Tanner stage in boys. For rs2234693 (PvuII) and rs9340799 (XbaI) polymorphisms, differences in spinal ABMC in late puberty were 2-fold greater in girls who were homozygous for the C and G alleles, respectively (P = 0.001). For rs7757956, the difference in total body less head ABMC in late puberty was 50% less in individuals homozygous or heterozygous for the A allele (P = 0.006). Conclusions: Gains in ABMC in late pubertal girls are strongly associated with ESR1 polymorphisms, suggesting that estrogen contributes to this process via an estrogen receptor α-dependent pathway.

Effect of an estrogen receptor-α intron 4 polymorphism on fat mass in 11-year-old children

Context: in the ESR1 gene encoding estrogen receptor (ER)-α may be associated with fat mass in adults. Objectives: The objective of the study was to establish whether ESR1 polymorphisms influence fat mass in childhood. Design: This was a cross-sectional analysis after genotyping of rs9340799, rs2234693, and rs7757956 ESR1 polymorphisms. Setting: The Avon Longitudinal Study of Parents and Children (ALSPAC) was a population-based prospective study. Participants: Participants included 3097 11-yr-old children with results for ESR1 genotyping, puberty measures, and dual-energy x-ray absorptiometry results. Outcomes: Relationships between ESR1 polymorphisms and indices of body composition were measured. Results: The rs7757956 polymorphism was associated with fat mass (P = 0.002). Total body fat mass (adjusted for height) was reduced by 6% in children with TA/AA genotypes, and risk of being overweight (≥85th centile of fat mass) was decreased by 20%. This genetic effect appeared to interact with puberty in girls (P = 0.05 for interaction): in those with the TT genotype, total body fat mass (adjusted for height) was 18% higher in Tanner stages 3-5 vs. stages 1-2; the equivalent difference was 7% in those with TA/AA genotypes. Furthermore, the risk of being overweight was 36% lower in girls with TA/AA genotypes in Tanner stages 3-5, but no reduction was seen in those in stages 1-2. Neither rs9340799 nor rs2234693 polymorphisms were associated with body composition measures. Conclusions: Fat mass in 11-yr-old children was related to the rs7757956 ESR1 polymorphism. This association was strongest in girls in more advanced puberty, in whom the risk of being overweight was reduced by 36% in those with the TA/AA genotype.

Suggestive linkage of the parathyroid receptor type 1 to osteoporosis

We have investigated the role of 23 candidate genes in the control of bone mineral density (BMD) by linkage studies in families of probands with osteoporosis (lumbar spine [LS] or femoral neck [FN] BMD T score < -2.5) and low BMD relative to an age- and gender-matched cohort (Z score < -2.0). One hundred and fifteen probands (35 male, 80 female) and 499 of their first- or second-degree relatives (223 males and 276 females) were recruited for the study. BMD was measured at the LS and FN using dual-energy X-ray absorptiometry and expressed as age- and gender-matched Z scores corrected for body mass index. The candidate genes studied were the androgen receptor, type I collagen A1 (COLIA1), COLIA2, COLIIA1, vitamin D receptor (VDR), colony-stimulating factor 1, calcium-sensing receptor, epidermal growth factor (EGF), estrogen receptor 1 (ESR1), fibrillin type 1, insulin-like growth factor 1, interleukin-1 alpha (IL-1α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-11 (IL-11), osteopontin, parathyroid hormone (PTH), PTH-related peptide, PTH receptor type 1 (PTHR1), transforming growth factor-beta 1, and tumor necrosis factors alpha and beta. Sixty-four microsatellites lying close to or within these genes were investigated for linkage with BMD. Using the program MapMaker/Sibs there was suggestive evidence of linkage between BMD and PTHR1 (maximum LOD score obtained [MLS] 2.7-3.5). Moderate evidence of linkage was also observed with EGF (MLS 1.8), COLIA1 (MLS 1.7), COLIIA1/VDR (MLS 1.7), ESR1 (MLS 1.4), IL-1α (MLS 1.4), IL-4 (MLS 1.2), and IL-6 (MLS 1.2). Variance components analysis using the program ACT, correcting for proband-wise ascertainment, also showed evidence of linkage (p ≤0.05) at markers close to or within the candidate genes IL- 1α, PTHR1, IL-6, and COLIIA1/VDR. Further studies will be required to confirm these findings, to refine the location of gene responsible for the observed linkage, and to screen the candidate genes targeted at these loci for mutations.

Chemotherapy pretreatment sensitizes solid tumor-derived cell lines to Vα24+ NKT cell-mediated cytotoxicity

There is an increasing awareness of the therapeutic potential for combining immune-based therapies with chemotherapy in the treatment of malignant diseases, but few published studies evaluate possible cytotoxic synergies between chemotherapy and cytotoxic immune cells. Human Vα24 +/Vβ11+ NKT cells are being evaluated for use in cell-based immunotherapy of malignancy because of their immune regulatory functions and potent cytotoxic potential. In this study, we evaluated the cytotoxicity of combinations of chemotherapy and NKT cells to determine whether there is a potential to combine these treatment modalities for human cancer therapy. The cytotoxicity of NKT cells was tested against solid-tumor derived cell lines NCI-H358, DLD-1, HT-29, DU-145, TSU-Pr1 and MDA-MB231, with or without prior treatment of these target cells, with a range of chemotherapy agents. Low concentrations of chemotherapeutic agents led to sensitization of cell lines to NKT-mediated cytotoxicity, with the greatest effect being observed for prostate cancer cells. Synergistic cytotoxicity occurred in an NKT cell in a dose-dependent manner. Chemotherapy agents induced upregulation of cell surface TRAIL-R2 (DR5) and Fas (CD95) expression, increasing the capacity for NKT cells to recognize and kill via TRAIL- and FasL-mediated pathways. We conclude that administration of cytotoxic immune cells after chemotherapy may increase antitumor activities in comparison with the use of either treatment alone.