Design, synthesis, and biological evaluation of bivalent ligands targeting dopamine D2-like receptors and the μ-opioid receptor

Currently, there is mounting evidence that intermolecular receptor-receptor interactions may result in altered receptor recognition, pharmacology and signaling. Heterobivalent ligands have been proven useful as molecular probes for confirming and targeting heteromeric receptors. This report describes the design and synthesis of novel heterobivalent ligands for dopamine D-2-like receptors (D-2-likeR) and the -opioid receptor (OR) and their evaluation using ligand binding and functional assays. Interestingly, we identified a potent bivalent ligand that contains a short 18-atom linker and combines good potency with high efficacy both in -arrestin2 recruitment for OR and MAPK-P for D4R. Furthermore, this compound was characterized by a biphasic competition binding curve for the D4R-OR heterodimer, indicative of a bivalent binding mode. As this compound possibly bridges the D4R-OR heterodimer, it could be used as a pharmacological tool to further investigate the interactions of D4R and OR

Ultrasound settings significantly alter arterial lumen and wall thickness measurements

Background. Flow-mediated dilation (FMD) and carotid intima-medial thickness (CIMT), measured by ultrasound, are widely used to test the efficacy of cardioprotective interventions. Although assessment methods vary, automated edge-detecting image analysis software is routinely used to measure changes in FMD and CIMT. We aimed to quantify the effect that commonly adjusted ultrasound settings have on arterial lumen and wall thickness measurements made with CIMT measurement software. Methods. We constructed phantom arteries from a tissue-mimicking agar compound and scanned them in a water bath with a 10 MHz multi-frequency linear-array probe attached to a high-resolution ultrasound machine. B-mode images of the phantoms were recorded with dynamic range (DR) and gain set at five decibel (dB) increments from 40 dB to 60 dB and -10 dB to +10 dB respectively. Lumen diameter and wall-thickness were measured off-line using CIMT measurement software. Results. Lumen measurements: there was a strong linear relationship between DR and gain and measured lumen diameter. For a given gain level, a 5 dB increase in DR reduced the measured lumen diameter by 0.02 ± 0.004 mm (p \u3c 0.001). For a given DR level, a 5 dB increase in gain reduced measured lumen diameter by 0.04 ± 0.004 mm (p \u3c 0.001). A 5 mm increase in distance between the ultrasound probe and the artery reduced measured lumen diameter by 0.04 ± 0.03 mm (p \u3c 0.001). CIMT measurements: For a fixed gain level, a 5 dB increase in DR increased measured wall thickness by 0.003 ± 0.002 mm (p \u3c 0.001). The effects of increasing gain were not consistent and appeared to vary depending on the distance between the artery and the ultrasound probe and the thickness of the artery wall. Conclusion. DR, gain and probe distance significantly alter lumen diameter and CIMT measurements made using image analysis software. When CIMT and FMD are used to test the efficacy of cardioprotective interventions, the DR, gain and probe position used to record baseline scans should be documented and replicated in post-treatment scans in individual trial subjects. If more than one sonographer or imaging centre is used to collect data, the study protocol should document specific DR and gain settings to be used in all subjects

Desacetyl-α-melanocyte stimulating hormone and α-melanocyte stimulating hormone are required to regulate energy balance.

OBJECTIVE: Regulation of energy balance depends on pro-opiomelanocortin (POMC)-derived peptides and melanocortin-4 receptor (MC4R). Alpha-melanocyte stimulating hormone (α-MSH) is the predicted natural POMC-derived peptide that regulates energy balance. Desacetyl-α-MSH, the precursor for α-MSH, is present in brain and blood. Desacetyl-α-MSH is considered to be unimportant for regulating energy balance despite being more potent (compared with α-MSH) at activating the appetite-regulating MC4R in vitro. Thus, the physiological role for desacetyl-α-MSH is still unclear. METHODS: We created a novel mouse model to determine whether desacetyl-α-MSH plays a role in regulating energy balance. We engineered a knock in targeted QKQR mutation in the POMC protein cleavage site that blocks the production of both desacetyl-α-MSH and α-MSH from adrenocorticotropin (ACTH1-39). RESULTS: The mutant ACTH1-39 (ACTHQKQR) functions similar to native ACTH1-39 (ACTHKKRR) at the melanocortin 2 receptor (MC2R) in vivo and MC4R in vitro. Male and female homozygous mutant ACTH1-39 (Pomctm1/tm1) mice develop the characteristic melanocortin obesity phenotype. Replacement of either desacetyl-α-MSH or α-MSH over 14 days into Pomctm1/tm1 mouse brain significantly reverses excess body weight and fat mass gained compared to wild type (WT) (Pomcwt/wt) mice. Here, we identify both desacetyl-α-MSH and α-MSH peptides as regulators of energy balance and highlight a previously unappreciated physiological role for desacetyl-α-MSH. CONCLUSIONS: Based on these data we propose that there is potential to exploit the naturally occurring POMC-derived peptides to treat obesity but this relies on first understanding the specific function(s) for desacetyl-α-MSH and α-MSH

Carotid intima-medial thickness measured on multiple ultrasound frames: evaluation of a DICOM-based software system

United Kingdo

Genetic and Mechanistic Evaluation for the Mixed-Field Agglutination in B3 Blood Type with IVS3+5G>A ABO Gene Mutation

Background: The ABO blood type B3 is the most common B subtype in the Chinese population with a frequency of 1/900. Although IVS3+5G.A (rs55852701) mutation of B gene has been shown to associate with the development of B3 blood type, genetic and mechanistic evaluation for the unique mixed-field agglutination phenotype has not yet been completely addressed. Methodology/Principal Findings: In this study, we analyzed 16 cases of confirmed B3 individuals and found that IVS3+5G.A attributes to all cases of B3. RT-PCR analyses revealed the presence of at least 7 types of aberrant B3 splicing transcripts with most of the transcripts causing early termination and producing non-functional protein during translation. The splicing transcript without exon 3 that was predicted to generate functional B3 glycosyltransferase lacking 19 amino acids at the N-terminal segment constituted only 0.9 % of the splicing transcripts. Expression of the B3 cDNA with exon 3 deletion in the K562 erythroleukemia cells revealed that the B3 glycosyltransferase had only 40 % of B1 activity in converting H antigen to B antigen. Notably, the typical mixed-field agglutination of B3-RBCs can be mimicked by adding anti-B antibody to the K562-B3 cells. Conclusions/Significance: This study thereby demonstrates that both aberrant splicing of B transcripts and the reduced B3 glycosyltransferase activity contribute to weak B expression and the mixed-field agglutination of B3, adding to th

Trends in healthcare utilization among older Americans with colorectal cancer: A retrospective database analysis

<p>Abstract</p> <p>Background</p> <p>Analyses of utilization trends (cost drivers) allow us to understand changes in colorectal cancer (CRC) costs over time, better predict future costs, identify changes in the use of specific types of care (eg, hospice), and provide inputs for cost-effectiveness models. This retrospective cohort study evaluated healthcare resource use among US Medicare beneficiaries diagnosed with CRC between 1992 and 2002.</p> <p>Methods</p> <p>Cohorts included patients aged 66+ newly diagnosed with adenocarcinoma of the colon (n = 52,371) or rectum (n = 18,619) between 1992 and 2002 and matched patients from the general Medicare population, followed until death or December 31, 2005. Demographic and clinical characteristics were evaluated by cancer subsite. Resource use, including the percentage that used each type of resource, number of hospitalizations, and number of hospital and skilled nursing facility days, was evaluated by stage and subsite. The number of office, outpatient, and inpatient visits per person-year was calculated for each cohort, and was described by year of service, subsite, and treatment phase. Hospice use rates in the last year of life were calculated by year of service, stage, and subsite for CRC patients who died of CRC.</p> <p>Results</p> <p>CRC patients (mean age: 77.3 years; 44.9% male) used more resources than controls in every category (<it>P </it>< .001), with the largest differences seen in hospital days and home health use. Most resource use (except hospice) remained relatively steady over time. The initial phase was the most resource intense in terms of office and outpatient visits. Hospice use among patients who died of CRC increased from 20.0% in 1992 to 70.5% in 2004, and age-related differences appear to have evened out in later years.</p> <p>Conclusion</p> <p>Use of hospice care among CRC decedents increased substantially over the study period, while other resource use remained generally steady. Our findings may be useful for understanding CRC cost drivers, tracking trends, and forecasting resource needs for CRC patients in the future.</p

A new approach to treatment of resistant gram-positive infections: potential impact of targeted IV to oral switch on length of stay

BACKGROUND: Patients prescribed intravenous (IV) glycopeptides usually remain in hospital until completion of this treatment. Some of these patients could be discharged earlier if a switch to an oral antibiotic was made. This study was designed to identify the percentage of inpatients currently prescribed IV glycopeptides who could be discharged earlier if a switch to an oral agent was used, and to estimate the number of bed days that could be saved. We also aimed to identify the patient group(s) most likely to benefit, and to estimate the number of days of IV therapy that could be prevented in patients who remained in hospital. METHODS: Patients were included if they were prescribed an IV glycopeptide for 5 days or more. Predetermined IV to oral antibiotic switch criteria and discharge criteria were applied. A multiple logistic regression model was used to identify the characteristics of the patients most likely to be suitable for earlier discharge. RESULTS: Of 211 patients, 62 (29%) could have had a reduced length of stay if they were treated with a suitable oral antibiotic. This would have saved a total of 649 inpatient days (median 5 per patient; range 1–54). A further 31 patients (15%) could have switched to oral therapy as an inpatient thus avoiding IV line use. The patients most likely to be suitable for early discharge were those with skin and soft tissue infection, under the cardiology, cardiothoracic surgery, orthopaedics, general medical, plastic surgery and vascular specialities, with no high risk comorbidity and less than five other regularly prescribed drugs. CONCLUSION: The need for glycopeptide therapy has a significant impact on length of stay. Effective targeting of oral antimicrobials could reduce the need for IV access, allow outpatient treatment and thus reduce the length of stay in patients with infections caused by antibiotic resistant gram-positive bacteria

Perceived control over condom use among sex workers in Madagascar: a cohort study

<p>Abstract</p> <p>Background</p> <p>Women's perceived control over condom use has been found to be an important determinant of actual condom use in some studies. However, many existing analyses used cross-sectional data and little quantitative information exists to characterize the relationships between perceived control and actual condom use among sex worker populations.</p> <p>Methods</p> <p>We assessed the association between measures of perceived condom use control and self-reported use of male condoms employing data from a longitudinal pilot study among 192 sex workers in Madagascar.</p> <p>Results</p> <p>In multivariable models, a lack of perceived control over condom use with a main partner and having a main partner ever refuse to use a condom when asked were both associated with an increased number of sex acts unprotected by condoms in the past week with a main partner (RR 1.86; 95% CI 1.21-2.85; RR 1.34; 95% CI 1.03-1.73, respectively). Conversely, no measure of condom use control was significantly associated with condom use with clients.</p> <p>Conclusion</p> <p>Perceived control over condom use was an important determinant of condom use with main partners, but not clients, among sex workers in Madagascar. Programs working with sex workers should reach out to main and commercial partners of sex workers to increase male condom use.</p

Differential gene expression in human granulosa cells from recombinant FSH versus human menopausal gonadotropin ovarian stimulation protocols

<p>Abstract</p> <p>Background</p> <p>The study was designed to test the hypothesis that granulosa cell (GC) gene expression response differs between recombinant FSH and human menopausal gonadotropin (hMG) stimulation regimens.</p> <p>Methods</p> <p>Females < 35 years-old undergoing IVF for tubal or male factor infertility were prospectively randomized to one of two stimulation protocols, GnRH agonist long protocol plus individualized dosages of (1) recombinant (r)FSH (Gonal-F) or (2) purified human menopausal gonadotropin (hMG; Menopur). Oocytes were retrieved 35 h post-hCG, and GC were collected. Total RNA was extracted from each GC sample, biotinylated cRNA was synthesized, and each sample was run on Human Genome Bioarrays (Applied Microarrays). Unnamed genes and genes with <2-fold difference in expression were excluded.</p> <p>Results</p> <p>After exclusions, 1736 genes exhibited differential expression between groups. Over 400 were categorized as signal transduction genes, ~180 as transcriptional regulators, and ~175 as enzymes/metabolic genes. Expression of selected genes was confirmed by RT-PCR. Differentially expressed genes included A kinase anchor protein 11 (AKAP11), bone morphogenetic protein receptor II (BMPR2), epidermal growth factor (EGF), insulin-like growth factor binding protein (IGFBP)-4, IGFBP-5, and hypoxia-inducible factor (HIF)-1 alpha.</p> <p>Conclusions</p> <p>Results suggest that major differences exist in the mechanism by which pure FSH alone versus FSH/LH regulate gene expression in preovulatory GC that could impact oocyte maturity and developmental competence.</p