Medication Adherence and Belief about Medication among Vietnamese Patients with Chronic Cardiovascular Diseases within the Context of Implementing Measures to Prevent COVID-19.

BACKGROUND: Long-term adherence is crucial for optimal treatment outcomes in chronic cardiovascular diseases (CVDs), especially throughout the COVID-19 wide-spreading periods, making patients with chronic CVDs vulnerable subjects. AIM: To investigate the relationship between the characteristics, beliefs about prescribed medication, COVID-19 prevention measures, and medication adherence among patients with chronic CVDs. METHODS: This is a cross-sectional study of outpatients with chronic CVDs in Southern Vietnam. The specific parts regarding the Beliefs about Medicines Questionnaires (BMQ-Specific) and the General Medication Adherence Scale (GMAS) were applied to assess the beliefs about and adherence to medication. The implementation measures to prevent COVID-19 in patients were evaluated according to the 5K message (facemask, disinfection, distance, no gathering, and health declaration) of the Vietnam Ministry of Health. A multivariable logistic regression with the Backward elimination (Wald) method was used to identify the associated factors of medication adherence. RESULTS: A slightly higher score in BMQ-Necessity compared to BMQ-Concerns was observed. A total of 40.7% of patients were recorded as having not adhered to their medications. Patients' behavior was most frequently self-reported by explaining their non-adherence (34.7%). Statistical associations were found between rural living place, unemployment status, no or only one measure(s) of COVID-19 prevention application, and medication adherence. CONCLUSION: During the COVID-19 spreading stage, patients generally showed a positive belief about medication when they rated the importance of taking it higher than its side effects. The data analysis suggested that rather than patients' beliefs, the clinicians should consider the patient factors, including living place, employment, and the number of epidemic preventive measures applied for guiding the target patients for improving medication adherence.

Concomitant neuroleptic malignant syndrome and diabetes insipidus.

ABSTRACT: Each year, nearly one-fifth of adults in the United States are prescribed at least one psychotropic medication. An increased trend in psychiatric polypharmacy has heightened awareness of drug-drug interactions and the tracking of adverse drug reactions. This article describes a patient who developed concomitant neuroleptic malignant syndrome (NMS) and nephrogenic diabetes insipidus during cross-titration of his antipsychotics while on lithium. The patient's mild form of NMS in turn caused hypovolemia and acute kidney injury. This case study highlights the dangers of polypharmacy and how it can obscure the presentation of even classic adverse reactions.

δ-Tocopherol derivatives from the leaves of Muntingia calabura L.

From an ethyl acetate-soluble fraction of the leaves of Muntingia calabura, one new trimeric δ-tocopherol derivative named as tocomuntin A (1), together with three known δ-tocopherol derivatives (2-4) were isolated. Their structures were elucidated based on the interpretation of NMR and MS spectroscopic data. In this work, δ-tocopherol (3) was found to have α-glucosidase inhibitory activity for the first time (IC50, 47.3 µM).

Characteristics of Rheoencephalography and some Associated Factors on Menopausal Women.

The significant drop in estrogen levels during menopause increases the cardiovascular risks, one of which is cerebrovascular atherosclerosis. Research on rheoencephalography (REG) parameters for the early diagnosis of cerebrovascular atherosclerotic lesions is of great interest to scientists because of its ease of implementation, low cost, and non-invasiveness. The objectives of study are to evaluate the vascular tone, cerebral circulation flow in each hemisphere of the brain of menopausal women, and some associated factors through waveform characteristics and parameters in REG. A controlled cross-sectional descriptive study was conducted on a group of patients including 80 menopausal women and a control group of 46 menstruating women. All patients were measured REG in the frontal-occipital leads by VasoScreen 5000 impedance REG meter. In menopausal women, the percentage of sharp waves, the percentage of clear side waves, and the average REG were all lower than in the control group (p<0.01). The mean conduction time and mean slope ratio was lower than the control group (p<0.001). The mean peak time was higher than the control group (p<0.01). The mean elasticity index (alpha/T) was higher than the control group (p<0.001). Menopausal women have increased vascular tone, the highest in the group of women 50-60 years old, menopause <5 years, having a habit of eating red meat; and decreased blood flow intensity, the highest in the group of women <50 years old. However, the difference was statistically significant only in the left hemisphere (p<0.05). Vascular hypertonia in menopausal women with central obesity was higher than in the non-obese group in both hemispheres (p<0.05). In conclusion, menopausal women had atherosclerosis in both hemispheres of the brain, which was clearly shown in the rate of increased vascular tone. Central obesity may increase the risk of vascular hypertonia 3.75 times in the right and 5.44 times in the left hemisphere.

Brunner's gland hyperplasia associated with lipomatous pseudohypertrophy of the pancreas presenting with gastrointestinal bleeding: A case report.

BACKGROUND: Brunner's gland hyperplasia (BGH) is a rare benign lesion of the duodenum. Lipomatous pseudohypertrophy (LiPH) of the pancreas is an extremely rare disease. Because each condition is rare, the probability of purely coincidental coexistence of both conditions is extremely low. CASE SUMMARY: We report a 26-year-old man presenting to our hospital with symptoms of recurrent upper gastrointestinal bleeding. Upper gastrointestinal endoscopy showed a huge pedunculated polypoid lesion in the duodenum with bleeding at the base of the lesion. Histopathological examination of the duodenal biopsy specimens showed BGH. Besides, abdominal computed tomography and magnetic resonance imaging revealed marked fat replacement over the entire pancreas, confirmed by histopathological evaluation on percutaneous pancreatic biopsies. Based on the radiological and histological findings, LiPH of the pancreas and BGH were diagnosed. The patient refused any surgical intervention. Therefore, he was managed with supportive treatment. The patient's symptoms improved and there was no further bleeding. CONCLUSION: This is the first well-documented case showing the coexistence of LiPH of the pancreas and BGH.

Molecular Identification and Characterization of Probiotic Bacillus Species with the Ability to Control Vibrio spp. in Wild Fish Intestines and Sponges from the Vietnam Sea.

Vibriosis in farmed animals is a serious threat to aquaculture worldwide. Using probiotics and anti-Vibrio antimicrobial substances in aquaculture systems can be a means of preventing Vibrio infections. Therefore, we aimed to characterize and compare 16 potential anti-Vibrio probiotics (Vi+) isolated from marine sponges and fish intestines collected from the Vietnam Sea, as well as an anti-Vibrio bacteriocin to fully explore their application potentials. 16S rRNA sequencing confirmed all Vi+ to be Bacillus species with different strain variants across two sample types. An obvious antimicrobial spectrum toward Gram-negative bacteria was observed from intestinal Vi+ compared to sponge-associated Vi+. The reason was the higher gene frequency of two antimicrobial compounds, non-ribosomal peptides (NRPS) and polyketide type-I (PKS-I) from intestinal Vi+ (66.7%) than sponge-associated Vi+ (14.3% and 0%, respectively). Additionally, a three-step procedure was performed to purify an anti-Vibrio bacteriocin produced by B. methylotrophicus NTBD1, including (i) solvent extraction of bacteriocin from cells, (ii) hydrophobic interaction chromatography, and (iii) reverse-phase HPLC. The bacteriocin had a molecular weight of ~2-5 kDa, was sensitive to proteolysis and thermally stable, and showed a broad antimicrobial spectrum, all of which are essential properties for promising feed additives. This study provides necessary information of the potential of probiotic Bacillus species with anti-Vibrio antimicrobial properties to study their further use in sustainable aquaculture.

Comparison between acupuncture therapy and gabapentin for chronic pain: a pilot study.

BACKGROUND: We examined whether the effect of true electroacupuncture on pain and functionality in chronic pain participants can be differentiated from that of medication (gabapentin) by analyzing quantitative sensory testing (QST). METHODS: We recruited chronic back and neck pain participants who received six sessions (twice weekly) of true electroacupuncture versus sham electroacupuncture or 3 weeks of gabapentin versus placebo treatment. QST profiles, pain scores, and functionality profile were obtained at baseline (visit 1) and after three sessions (visit 4) or six sessions (visit 7) of acupuncture or 3 weeks of gabapentin or placebo. RESULTS: A total of 50 participants were analyzed. We found no differences in QST profile changes (p = 0.892), pain reduction (p = 0.222), or functionality (p = 0.254) between the four groups. A major limitation of this pilot study was the limited number of study participants in each group. CONCLUSION: This pilot study suggests that a large-scale clinical study with an adequate sample size would be warranted to compare acupuncture and medication therapy for chronic pain management. TRIAL REGISTRATION NUMBER: NCT01678586 (ClinicalTrials.gov).

The Role of Lung Ultrasonography in Etiologic Diagnosis of Acute Dyspnea in a Resource Limited Setting.

The aim of the current study was to describe lung ultrasonography (LUS) characteristics and to evaluate the agreement between LUS and chest radiography (CXR) in diagnosis of four conditions causing most acute dyspnea in children, namely, pneumonia, pleural effusion, pneumothorax and acute pulmonary edema in children at a teaching hospital in Vietnam. We reviewed the records of the chidren between January and June 2018, who presented to emergency department (ED) or pediatric intensive care unit (PICU) at children hospital 1 (CH1) with acute dyspnea and had final diagnosis of one of four etiologies including pneumonia, pleural effusion, pneumothorax and acute pulmonary edema. All patients underwent CXR and LUS at the time of admission. Eighty-one children with acute dyspnea including pneumonia (n=65, 80%), pleural effusion (n=9, 11%), pneumothorax (n=3, 4%) and acute pulmonary edema (n=4, 5%) were enrolled. LUS was identified among 100% of cases with pleural effusion and pneumothorax (CXR only showed 73.3% and 50%, respectively); 92.3% of cases with pneumonia (CXR showed 93.8%) and only 75% of cases with acute pulmonary edema (CXR showed 50%). When comparing LUS with CXR, we noticed a good agreeement between the 2 methods in the diagnosis of pneumonia (kappa=0.64, p<0.001). LUS was shown to be a feasible and non-invasive technique which can help clinicians to comfirm the etiology of acute pulmonary dyspnea.

DNA-HPV transition rate and related factors in HPV-infected women in Can Tho city, Vietnam.

OBJECTIVES: To determine DNA-HPV transition rates and related factors in HPV-infected women 18-69 years of age in Can Tho City from 2013 to 2018. METHODS: Both a retrospective and a prospective cohort study were done. Interviews, gynaecological examinations and HPV testing by PCR (cervical fluid) were used to collect data. The results were recorded and compared with those of HPV in 2013 to assess the development of HPV over time. Transition was defined as conversion to HPV-positive state in 2018 from a negative state in 2013. No transition was defined as clearance of HPV when the positive 2013 result was negative in 2018 or when the result remained negative or positive in 2013 and 2018. Factors related to the change were analysed. RESULTS: Among a sample size of 204 cases, the average age of participants was 48.9 ± 10.4 years. Women >45 comprised 63.2% of participants; 82.8% lived with their husbands, 6.4% were divorced, and 2.9% lived apart from their husbands due to work. After 5 years of observation, 16.2% of DNA-HPV cases had converted to HPV-positive state and 66.2% of DNA-HPV cases had cleared to HPV-negative state. Factors related to conversion to HPV-positive state were age ≤ 45 years (3.14 times higher risk of transition than in the >45 age group (95% CI: 1.12-8.8)); change of sexual partner (OR = 3.75 (95% CI: 1.15-12.2)); change of sexual partner by husband (OR = 3.69 (95% CI: 1.20-11.3); sexually transmitted diseases (OR = 5.19 (95% CI: 1.09-24.8)); and a history of vacuum aspiration or dilation and evacuation abortion (OR = 1.4 (95% CI: 0.29-6.4)). CONCLUSIONS: 16.2% of women with DNA-HPV transition converted to HPV-positive state. Changes in sexual habits increase the risk of developing HPV positivity.

TAUX DE TRANSITION ADN-VPH ET FACTEURS CONNEXES CHEZ LES FEMMES INFECTÉES PAR LE VPH À CAN THO CITY, VIETNAM: OBJECTIFS: Déterminer les taux de transition ADN-VPH et les facteurs connexes chez les femmes infectées par le VPH, âgées de 18 à 69 ans à Can Tho City de 2013 à 2018. MÉTHODES: Une étude de cohorte rétrospective et une prospective ont été effectuées. Des entretiens, des examens gynécologiques et des tests pour le VPH par PCR (liquide cervical) ont été utilisés pour collecter des données. Les résultats ont été enregistrés et comparés à ceux du VPH en 2013 afin d'évaluer l'évolution du VPH au fil du temps. La transition a été définie comme étant la conversion d'un état négatif au VPH en 2013 à un état positif en 2018. Aucune transition n'a été définie comme une élimination du VPH lorsque le résultat positif de 2013 était négatif en 2018 ou lorsque le résultat est resté négatif ou positif en 2013 et 2018. Les facteurs liés au changement ont été analysés. RÉSULTATS: Sur un échantillon de 204 cas, l'âge moyen des participantes était de 48,9 ± 10,4 ans. Les femmes > 45 ans représentaient 63,2% des participantes; 82,8% vivaient avec leur mari, 6,4% étaient divorcées et 2,9% vivaient séparées de leur mari à cause de leur travail. Après 5 ans d'observation, 16,2% des cas d'ADN-VPH étaient passés à l'état VPH positif et 66,2% des cas d'ADN-VPH avaient tout éliminé et étaient passés à l'état HPV négatif. Les facteurs liés à la conversion à l'état positif au VPH étaient les suivants: âge ≤ 45 ans (risque de transition de 3,14 fois supérieur à celui du groupe d'âge > 45 ans (IC95%: 1,12 à 8,8)), changement de partenaire sexuel (OR = 3,75 (IC95%: 1,15-12,2)), changement de partenaire sexuel par le mari (OR = 3,69 (IC95%: 1,20-11,3), maladies sexuellement transmissibles (OR = 5,19 (IC95%: 1,09-24,8)) et antécédents d'aspiration ou de dilatation et d'évacuation d'avortement (OR = 1,4 (IC95%: 0,29 à 6,4)). CONCLUSIONS: 16,2% des femmes présentant une transition ADN-VPH sont devenues positives au VPH. Les changements d'habitudes sexuelles augmentent le risque de développer une positivité au VPH.

Levodopa-induced dyskinesia: clinical features, incidence, and risk factors.

Symptoms of Parkinson's disease have been controlled with levodopa for many years; however, motor complications consisting of wearing off of medication effect and dyskinesias tend to occur within a few years of starting levodopa. Motor complications can begin a few months after taking levodopa, with the average time to onset estimated to be 6.5 years. Dyskinesias can be troublesome and require intervention. Levodopa-induced dyskinesia can be composed of a variety of movement disorders including chorea, dystonia, ballism, myoclonus, and akathisia. Based on the clinical pattern, the most common dyskinesia is chorea and choreoathetosis. The clinical manifestations can be divided into three main categories based on their clinical movement patterns and the temporal correlation between the occurrence of dyskinesia and the levodopa dosing: on or peak-dose dyskinesias, biphasic dyskinesias, and Off dyskinesias. Severe cases of dyskinesia have been reported, with the extreme being dyskinesia-hyperpyrexia syndrome. The prevalence of LID has been reported in many studies, but the reported incidence varies. The rate of LID development is from 3 to 94%. The prevalence of LID mainly depends on age at onset, disease duration, and severity, and duration of levodopa therapy. Some of the risk factors for the development of dyskinesia are modifiable. Modifiable risk factors include levodopa dose and body weight. Non-modifiable risk factors include age, gender, duration of disease, clinical subtype, disease progression, disease severity, and genetic factors.

Ligature induced peri-implantitis: tissue destruction and inflammatory progression in a murine model.

OBJECTIVES: The aim of this study was to investigate tissue destruction and inflammatory progression of ligature-induced peri-implantitis in mice and to establish an alternative murine model of peri-implantitis. MATERIAL AND METHODS: Sixty male C57BL/6NCrSlc mice (4-week-old) were used and the maxillary right first molars were extracted. Eight weeks after extraction, custom-made pure titanium machined screw type implants (0.8 × 1.5 mm) were placed, one implant per animal. Four weeks later, 5-0 silk ligatures were applied around implant necks to induce peri-implantitis. Animals were sacrificed at 0 (before ligature), 7, 14, 21 and 28 days after ligature. Half of the samples were analyzed radiologically and histologically to measure bone level change, osteoclast number, density, and distribution. The rest of the samples was used to determine the relative mRNA expression levels of IL-1 and TNF-α with RT-PCR analysis. RESULTS: Bone levels at all sites (buccal, palatal, mesial, distal) decreased 40-50% significantly 28 days after ligature (P < 0.01). Osteoclast number at all post-ligature time points increased significantly (P < 0.05). However, their density at day 28 decreased significantly compared to that of day 21 (P < 0.05). Accordingly, IL-1 and TNF-α mRNA expression increased significantly at the early time points but decreased significantly at day 28 after ligature (P < 0.05). CONCLUSIONS: Inflammatory response followed by significant peri-implant bone resorption suggested 28 days ligation is sufficient to successfully induce peri-implantitis in the current mice model. This model might open a new avenue to study the pathogenesis and mechanism of peri-implantitis.

Profiles of Urine Drug Test in Clinical Pain Patients vs Pain Research Study Subjects.

OBJECTIVE: To examine similarities and differences in urine drug test (UDT) results in clinical pain patients and pain subjects participating in pain research studies. DESIGN: An observational study with retrospective chart review and data analysis. METHODS: We analyzed 1,874 UDT results obtained from 1) clinical pain patients (Clinical Group; n = 1,529) and 2) pain subjects consented to participate in pain research studies (Research Group; n = 345). Since several medications such as opioids used in pain management are drugs of abuse (DOA) and can result in a positive UDT, we specifically identified those cases of positive UDT due to nonprescribed DOA and designated these cases as positive UDT with DOA (PUD). RESULTS: We found that 1) there was a higher rate of PUD in clinical pain patients (41.3%) than in pain research study subjects (14.8%); 2) although subjects in the Research Group were informed ahead of time that UDT will be conducted as a screening test, a substantial number (14.8%) of pain research study subjects still showed PUD; 3) there were different types of DOA between clinical pain patients (cannabinoids as the top DOA) and research study subjects (cocaine as the top DOA); and 4) a common factor associated with PUD was opioid therapy in both Clinical Group and Research Group. CONCLUSION: These results support previous findings that PUD is a common finding in clinical pain patients, particularly in those prescribed opioid therapy, and we suggest that UDT be used as routine screening testing in pain research studies.

Effects of Spinal Cord Stimulation on Pain Thresholds and Sensory Perceptions in Chronic Pain Patients.

OBJECTIVE: Spinal cord stimulation (SCS) has been in clinical use for nearly four decades. In earliest observations, researchers found a significant increase in pain threshold during SCS therapy without changes associated with touch, position, and vibration sensation. Subsequent studies yielded diverse results regarding how SCS impacts pain and other sensory thresholds. This pilot study uses quantitative sensory testing (QST) to objectively quantify the impact of SCS on warm sensation, heat pain threshold, and heat pain tolerance. MATERIALS AND METHODS: Nineteen subjects with an indwelling SCS device for chronic pain were subjected to QST with heat stimuli. QST was performed on an area of pain covered with SCS-induced paresthesia and an area without pain and without paresthesia, while the SCS was turned off and on. The temperature at which the patient detected warm sensation, heat pain, and maximal tolerable heat pain was used to define the thresholds. RESULTS: We found that all three parameters, the detection of warm sensation, heat pain threshold, and heat pain tolerance, were increased during the period when SCS was on compared with when it was off. This increase was observed in both painful and non-painful sites. CONCLUSION: The observed pain relief during SCS therapy seems to be related to its impact on increased sensory threshold as detected in this study. The increased sensory threshold on areas without pain and without the presence of SCS coverage may indicate a central (spinal and/or supra-spinal) influence from SCS.

Effect of 1.5% Topical Diclofenac on Clinical Neuropathic Pain.

BACKGROUND: Neuropathic pain is a condition resulting from injury to the peripheral and/or central nervous system. Despite extensive research over the last several decades, neuropathic pain remains difficult to manage. METHODS: The authors conducted a randomized, placebo-controlled, double-blinded, and crossover clinical trial to examine the effect of 1.5% topical diclofenac (TD) on neuropathic pain. The authors hypothesized that 1.5% TD would reduce the visual pain score and improve both quantitative sensory testing and functional status in subjects with neuropathic pain. The authors recruited subjects with postherpetic neuralgia and complex regional pain syndrome. The primary outcome was subject's visual pain score. RESULTS: Twenty-eight subjects completed the study (12 male and 16 female) with the mean age of 48.8 yr. After 2 weeks of topical application, subjects in 1.5% TD group showed lower overall visual pain score compared with placebo group (4.9 [1.9] vs. 5.6 [2.1], difference: 0.8; 95% CI, 0.1 to 1.3; P = 0.04) as well as decreased burning pain (2.9 [2.6] vs. 4.3 [2.8], difference, 1.4; 95% CI, 0.2 to 2.6; P = 0.01). There were no statistical differences in constant pain, shooting pain, or hypersensitivity over the painful area between the groups. This self-reported improvement of pain was corroborated by the decreased pain summation detected by quantitative sensory testing. There were no statistically significant changes in functional status in these subjects. There were no complications in both groups. CONCLUSION: The findings indicate that 1.5% TD may serve as an effective treatment option for patients with neuropathic pain from postherpetic neuralgia and complex regional pain syndrome.

Increased pain sensitivity in chronic pain subjects on opioid therapy: a cross-sectional study using quantitative sensory testing.

OBJECTIVE: The aim of this study was to compare the sensitivity to experimental pain of chronic pain patients on opioid therapy vs chronic pain patients on non-opioid therapy and healthy subjects by quantitative sensory testing (QST). SETTING: There is a growing body of evidence demonstrating that chronic use of opioid drugs may alter pain sensitivity. Identifying the characteristic changes in thermal pain sensitivity in chronic opioid users will be helpful in diagnosing pain sensitivity alterations associated with chronic opioid use. METHODS: Utilizing an office-based QST technique, we examined thermal pain threshold, tolerance, and temporal summation in 172 chronic pain subjects receiving opioid therapy, 121 chronic pain subjects receiving non-opioid therapy, and 129 healthy subjects. RESULTS: In chronic pain subjects receiving opioid therapy, there were detectable differences in QST characteristics compared with both chronic pain subjects receiving non-opioid therapy and healthy subjects. Specifically, in chronic pain subjects receiving opioid therapy, 1) sensitivity to heat pain was increased; threshold to heat pain was significantly lower; 2) tolerance to supra-threshold heat pain was significantly decreased; and 3) temporal pain summation was exacerbated, as compared with chronic pain subjects receiving non-opioid therapy. In a subgroup of chronic pain subjects receiving opioid therapy with increased heat pain sensitivity, their average opioid medication dosage was significantly higher than those who had an above-average heat pain threshold. Moreover, a subset of chronic pain subjects on opioid therapy exhibited a significant decrease in diffuse noxious inhibitory control (DNIC) compared with chronic pain subjects on non-opioid therapy. CONCLUSION: These findings suggest that a subset of QST parameters can reflect opioid-associated thermal pain sensitivity alteration, including decreased heat pain threshold, decreased cold and heat pain tolerance, diminished DNIC, and/or exacerbated temporal summation.

Clinical interpretation of opioid tolerance versus opioid-induced hyperalgesia.

Opioid analgesics are commonly used to manage moderate to severe pain. However, the long-term use of opioids could lead to opioid tolerance (OT) and opioid-induced hyperalgesia (OIH). Distinguishing OIH from OT would impact the practice of opioid therapy because opioid dose adjustment may differentially influence OT and OIH. Currently, there are no standard criteria of OT versus OIH causing considerable ambiguity in clinical interpretation and management of these conditions. The authors designed a practitioner-based survey consisting of 20 targeted questions. Answering these questions would require responders' actual clinical experiences with opioid therapy. The survey was conducted between 2011 and 2012 through direct mails or e-mails to 1,408 physicians who are currently practicing in the United States. The authors find that certain clinical characteristics (eg, increased pain despite opioid dose escalation) are often used by practitioners to make differential diagnosis of OT and OIH despite some overlap in their clinical presentation. A key difference in clinical outcome is that OT and OIH could be improved and exacerbated by opioid dose escalation, respectively. Our survey results revealed a significant knowledge gap in some responders regarding differential diagnosis and management of OT and OIH. The results also identified several issues, such as opioid dose adjustment and clinical comorbidities related to OT and OIH, which require future patient-based studies.

Lack of correlation between opioid dose adjustment and pain score change in a group of chronic pain patients.

UNLABELLED: Despite the increasing use of opioid analgesics for chronic pain management, it is unclear whether opioid dose escalation leads to better pain relief during chronic opioid therapy. In this study, we retrospectively analyzed clinical data collected from the Massachusetts General Hospital Center for Pain Medicine over a 7-year period. We examined 1) the impact of opioid dose adjustment (increase or decrease) on clinical pain score; 2) gender and age differences in response to opioid therapy; and 3) the influence of clinical pain conditions on the opioid analgesic efficacy. A total of 109 subjects met the criteria for data collection. We found that neither opioid dose increase, nor decrease, correlated with point changes in clinical pain score in a subset of chronic pain patients over a prolonged course of opioid therapy (an average of 704 days). This lack of correlation was consistent regardless of the type of chronic pain including neuropathic, nociceptive, or mixed pain conditions. Neither gender nor age differences showed a significant influence on the clinical response to opioid therapy in these subjects. These results suggest that dose adjustment during opioid therapy may not necessarily alter long-term clinical pain score in a group of chronic pain patients and that individualized opioid therapy based on the clinical effectiveness should be considered to optimize the treatment outcome. PERSPECTIVE: The study reports a relationship, or lack thereof, between opioid dose change and clinical pain score in a group of chronic pain patients. The study also calls for further investigation into the effectiveness of opioid therapy in the management of chronic nonmalignant pain conditions.

Effects of G-quartet DNA stationary phase destabilization on fibrinogen peptide resolution in capillary electrochromatography.

The migration of fibrinogen peptides in capillaries coated with G-quartet-forming DNA oligonucleotides in open-tubular CEC (OTCEC) was studied, in order to investigate factors affecting the retention of peptides on G-quartet DNA stationary phases. At 25 degrees C, the peptides eluted in the same order in OTCEC using a two-plane G-quartet DNA stationary phase as in CZE, including two peptides that were completely overlapped. It was found that baseline resolution of the coeluting peptides could be achieved in the OTCEC experiment, but not in CZE, at run temperatures of 35-40 degrees C. A stationary phase formed by a scrambled-sequence oligonucleotide that does not form a G-quartet did not provide any resolution of the two coeluting peptides, even at the higher temperatures, indicating that some destabilization of the G-quartet enhances resolution but that some degree of G-quartet structure is necessary. The effects of destabilization were further explored through variation of the cations (sodium or potassium) used in attachment of the G-quartet oligonucleotide to the capillary surface and in the mobile-phase buffer. Resolution was lower when a more stable, four-plane G-quartet stationary phase was used, supporting the conclusion that some flexibility in the G-quartet structure facilitates differential interactions that resolve otherwise coeluting peptides. The increase in peptide resolution upon destabilization of the G-quartet structure could prove to be an important factor in the application of G-quartet DNA stationary phases for nonaffinity-based separation of native proteins and peptides.

Selectivity of quadruplex DNA stationary phases toward amino acids in homodipeptides and alanyl dipeptides.

Series of dipeptides, including homodipeptides and alanyl dipeptides, were separated using quadruplex (G-quartet) DNA stationary phases in open-tubular capillary electrochromatography (OTCEC). The stationary phases were constructed by covalently attaching the DNA oligonucleotides to the inner capillary surface. Three different G-quartet forming oligonucleotides were investigated: the two-plane G-quartet forming thrombin-binding aptamer, the four-plane analogue of the thrombin-binding aptamer, and a two-plane oligonucleotide identical to the thrombin-binding aptamer except for the replacement of the guanine by thymine in the central bridging loop of the G-quartet structure. Results were compared with results obtained using capillary electrophoresis on a bare capillary and OTCEC using an oligonucleotide with the same base composition as the thrombin-binding aptamer but in a different sequence that does not allow G-quartet formation as the stationary phase.