Predictors of Adherence to an Antidepressant Medication Regimen Among Patients Diagnosed with Depression in Taiwan

This study explored the predictors of medication adherence among Taiwanese people with major depression and dysthymic disorder. Previous research indicates that depressed patients vary in compliance with their medication regimen. Poor compliance reduces the therapeutic effect of medication. Self-report questionnaires were used for this cross-sectional study conducted with 181 outpatients diagnosed with major depression or dysthymic disorder. About 50% of depressed patients reported good medication adherence. The predictors of adherence were patient income, treatment efficacy, and understanding the importance of continuing medication. Professionals should use collaborative communication and cultural values clarification with depressed patients and their families to improve the awareness of illness and to increase the likelihood of medication compliance.     

Detection of chymase activity using a specific peptide probe conjugated onto gold nanoparticles

Gold nanoparticles (AuNPs) can be applied in biosensors using fluorescence resonance energy transfer (FRET) technique. Based on this technique, we have established a sensitive and efficient biosensing method by modifying a peptide-probe onto AuNPs to detect proteinase enzyme activity in this study. This biosensing method was designed for chymase activity detection and applied in kidney disease diagnosis. In this study, 16 nm-AuNPs were used to construct the AuNPs-based fluorescence peptide probe (named AuNPs-peptide probe) for chymase activity determination. The peptide sequence is FITC-Acp-DRVYIHPFHLDDDDDC, which comprises a fluorophore at the N-terminal end, an enzyme (chymase) substrate (DRVYIHPFHL), a spacer (DDDDD) and cysteine (C) to conjugate to AuNPs surface. When the enzyme catalyzes the substrate sequence, the fluorophore drifts away from AuNPs and the fluorescence emitting signal can be excited at 495 nm and detected at 515 nm. The results indicate that the time required for the AuNPs-peptide probe for activity detection of chymase was only 15 min, and a linear correlation from 10 to 100 ng mL⁻¹ of chymase was acquired. The chymase reaction would be significantly inhibited by addition of specific chymase inhibitor chymostatin. The AuNPs-peptide probe was tested for the detection of high concentrations of trypsin and chymotrypsin, but only minor emitted fluorescence intensity was detected. According to these results, sensitivity and specificity of the AuNPs-peptide probe for chymase detection have been confirmed. AuNPs-peptide probe was successfully used for the detection of renal chymase activity; and the results indicate the pathogenically increased chymase activity in kidney tissue of nephropathic mice from aristolochic acid I treatment.

The gold nanoparticles (AuNPs) peptide probe functionalized with specific peptide sequences was developed for the sensitive and efficient detection of chymase activity.     

Disproportionate Reduction of Serotonin Transporter May Predict the Response and Adherence to Antidepressants in Patients with Major Depressive Disorder: A Positron Emission Tomography Study with 4-[18F]-ADAM

Background:

Many lines of evidence suggest the role of serotonin transporter (SERT)-mediated reuptake of serotonin in the pathophysiology and treatment of major depressive disorder (MDD). This study aimed to examine whether the pretreatment of SERT binding potential or SERT binding ratio between terminal projection regions relative to the midbrain raphe nuclei was associated with treatment outcomes to SERT-targeted antidepressants.

Methods:

We recruited 39 antidepressant-naïve patients with MDD and 39 heathy controls. Positron emission tomography with N,N-dimethyl-2-(2-amino-4-[¹⁸F]fluorophenylthio)benzylamine (4-[¹⁸F]-ADAM) was used to measure in vivo SERT availability prior to antidepressant treatment. The 21-item Hamilton Depression Rating Scale (HDRS) was use to assess the severity of depression from baseline to week 6. All the patients with MDD had HDRS scores of 18 or more.

Results:

Pretreatment SERT binding in the thalamus and striatum positively correlated with an early reduction in HDRS scores at week 3. Nonresponders and dropout patients showed a proportionate reduction in SERT binding in the terminal projection regions and midbrain compared to healthy controls. In contrast, a disproportionate reduction in SERT binding in the terminal projection regions relative to midbrain was observed in responders.

Conclusions:

The results of this study suggested that a disproportionate reduction in SERT binding between terminal projection regions and midbrain may predict better treatment outcomes in patients with MDD.     

Preoperative staging of gastric cancer by endoscopic ultrasound: the prognostic usefulness of ascites detected by endoscopic ultrasound

BACKGROUND: Endoscopic ultrasound (EUS) is the standard modality in local preoperative staging of gastric cancers and is reputedly able to detect ascites. However, the association between ascites detected by EUS and local tumor staging, peritoneal carcinomatosis, or survival after surgery is not well documented. GOALS: To assess the accuracy, sensitivity, and specificity of EUS in the preoperative staging and detection of ascites in gastric cancers. We also try to correlate ascites with histologic staging, tumor differentiation, and survival rate of gastric carcinoma after surgery. STUDY: The retrospective analysis was made in 57 consecutive patients with histologically confirmed gastric adenocarcinomas that underwent EUS before surgery. The accuracy of EUS was compared with the final surgical-pathologic findings. We estimated the prognostic usefulness by analyzing the clinicopathologic features of gastric adenocarcinomas and following up their survival rates. RESULTS: The overall T staging was 88% accurate by EUS. The accuracy for T staging was as follows: T1, 100%; T2, 33%; T3, 93%; and T4, 100%. About 50% of T2 cases were overstaged. The overall accuracy, sensitivity, and specificity of detecting lymph node metastasis by EUS were 79%, 79%, and 80%, respectively. One of the seven T1 cancers had regional lymph node metastasis, and it was missed by EUS, although the T classification was precisely staged based on finding submucosal invasion. A total of 22 patients (39%) had ascites detected by EUS; both the sensitivity and specificity of EUS in demonstrating ascites were 100% in our study. Ascites was significantly correlated with the depth of tumor invasion ( = 0.036), lymph node metastasis ( = 0.008), and poor cellular differentiation ( = 0.007), but it was not significantly correlated with macroscopic peritoneal carcinomatosis. The survival rate after surgical treatment was poor in those with gastric cancers with lymph node metastasis, ascites, or poorly differentiated tumors ( < 0.05). However, multivariate analysis showed that lymph node metastasis was the only significant prognostic predictor ( = 0.004). CONCLUSIONS: Endoscopic ultrasound is a valuable diagnostic tool in the local staging of gastric cancers and demonstration of ascites. Although the surgical treatment of gastric cancers with lymph node metastasis, ascites, or poor differentiation had poorer survival rate, only lymph node metastasis was proved to be a significant prognostic predictor in multivariate analysis.     

GPCR dimerization in brainstem nuclei contributes to the development of hypertension

Background and Purpose

μ-Opioid receptors, pro-opiomelanocortin and pro-enkephalin are highly expressed in the nucleus tractus solitarii (NTS) and μ receptor agonists given to the NTS dose-dependently increased BP. However, the molecular mechanisms of this process remain unclear. In vitro, μ receptors heterodimerize with α_2A-adrenoceptors. We hypothesized that α_2A-adrenoceptor agonists would lose their depressor effects when their receptors heterodimerize in the NTS with μ receptors.

Experimental Approach

We microinjected μ-opioid agonists and antagonists into the NTS of rats and measured changes in BP. Formation of μ receptor/α_2A-adrenoceptor heterodimers was assessed with immunofluorescence and co-immunoprecipitation methods, along with proximity ligation assays.

Key Results

Immunofluorescence staining revealed colocalization of α_2A-adrenoceptors and μ receptors in NTS neurons. Co-immunoprecipitation revealed interactions between α_2A-adrenoceptors and μ receptors. In situ proximity ligation assays confirmed the presence of μ receptor/α_2A-adrenoceptor heterodimers in the NTS. Higher levels of endogenous endomorphin-1 and μ receptor/α_2A-adrenoceptor heterodimers were found in the NTS of hypertensive rats, than in normotensive rats. Microinjection of the μ receptor agonist [D-Ala², MePhe⁴, Gly⁵-ol]-enkephalin (DAMGO), but not that of the α_2A-adrenoceptor agonist guanfacine, into the NTS of normotensive rats increased μ receptor/α_2A-adrenoceptor heterodimer formation and BP elevation. The NO-dependent BP-lowering effect of α_2A-adrenoceptor agonists was blunted following increased formation of μ receptor/α_2A-adrenoceptor heterodimers in the NTS of hypertensive rats and DAMGO-treated normotensive rats.

Conclusions and Implications

Increases in endogenous μ receptor agonists in the NTS induced μ receptor/α_2A-adrenoceptor heterodimer formation and reduced the NO-dependent depressor effect of α_2A-adrenoceptor agonists. This process could contribute to the pathogenesis of hypertension.     

Pharmacokinetic Interaction of the Direct Renin Inhibitor Aliskiren with Furosemide and Extended‐Release Isosorbide‐5‐Mononitrate in Healthy Subjects

This study investigated the pharmacokinetics, safety, and tolerability of aliskiren administered alone or in combination with either the loop diuretic furosemide or an oral extended‐release formulation of isosorbide‐5‐mononitrate (ISMN). In separate studies, 22 healthy subjects (ages 18–45 years) received either ISMN 40 mg or furosemide 20 mg once‐daily for 3 days followed by a 3‐day washout. Subjects then received aliskiren 300 mg once‐daily for 7 days followed by combination therapy for 3 days. Pharmacokinetic assessments were taken at regular intervals over 24 h after dosing on the last day of each treatment period. At steady state, aliskiren AUC_τ was decreased by 7% (geometric mean ratio [90% CI], 0.93 [0.84, 1.04]), and C_max by 20% (0.80 [0.65, 0.97]) with furosemide coadministration compared with aliskiren administration alone. Aliskiren coadministration reduced furosemide AUC_τ by 28% (0.72 [0.64, 0.81]) and C_max by 49% (0.51 [0.39, 0.66]) compared with furosemide alone. Coadministration of aliskiren and ISMN was associated with only minor changes in the pharmacokinetic parameters of aliskiren (AUC_τ 1.03 [0.90, 1.18]; C_max 0.94 [0.69, 1.29]) and ISMN (AUC_τ 0.88 [0.71, 1.10]; C_max 0.94 [0.79, 1.13]). Headache and dizziness were the most common adverse events in both studies; dizziness and BP values below normal (SBP <90 and/or DBP <50 mmHg) were more frequent with aliskiren and ISMN coadministration than with either agent alone. Coadministration of aliskiren and ISMN had no clinically relevant effect on either aliskiren or ISMN pharmacokinetics. In conclusion, coadministration of aliskiren and furosemide reduced furosemide exposure and had a minor effect on aliskiren pharmacokinetics. The clinical significance of reduced systemic exposure to furosemide during coadministration of aliskiren is uncertain.