Predictors of opioid use for rib fractures in a regional Australian hospital.

BACKGROUND: Rib fractures (RFs) are the leading type of single serious injury in New South Wales trauma patients. Uncontrolled pain drives the sequelae of atelectasis, pneumonia, respiratory failure, and death in severe cases. Opioids are the mainstay of management; however, they carry numerous adverse effects. Understanding patient or injury factors which predict opioid requirement is important to tailor management. Existing evidence is limited to metropolitan trauma centres (MTCs). METHODS: We conducted an observational, retrospective, single-centre cohort study of all admissions to Albury Wodonga Health diagnosed with one or more RFs and discharged between January 1st, 2017, and December 31st, 2022, inclusive. Data collected included demographics, injury characteristics, and management, including analgesia. LASSO regression was performed to determine predictors of average daily opioid use for the first five days of admission in oral morphine equivalents (mg). R2 and root mean square error (RMSE) were calculated to assess model performance. RESULTS: We included 624 patients. LASSO selected number of RFs, fracture displacement score, pulmonary contusion, new injury severity score, age, chest tube use, chronic pain history, opioid history and upper or middle lateral RF location categories as predictors. Sex, middle anterior, middle posterior, and lower RF location categories were excluded by LASSO. The out of sample R2 was 28.6 %. On the scale of log OME, the RMSE was 1.08. CONCLUSION: The model is effective at identifying predictors of opioid use in this regional centre, which are similar to those described in evidence from MTCs. However, the low R2 with wide prediction intervals limits its utility on an individual level.

Intraoperative methadone for day-case gynaecological laparoscopy: A double-blind, randomised controlled trial.

Optimal pain relief in day-case surgery is imperative to patient comfort and timely discharge from hospital. Short-acting opioids are commonly used for analgesia in modern anaesthesia, allowing rapid recovery after surgery. Plasma concentration fluctuations from repeated dosing of short-acting opioids can cause patients to oscillate between analgesia with potential adverse effects, and inadequate analgesia requiring rescue dosing. Methadone's unique pharmacology may offer effective and sustained analgesia with less opioid consumption, potentially reducing adverse effects. Using a double-blind, randomised controlled trial, we compared post-anaesthesia care unit opioid consumption between day-case gynaecological laparoscopy patients who received either intravenous methadone (10 mg), or short-acting opioids intraoperatively. The primary outcome was post-anaesthesia care unit opioid consumption in oral morphine equivalents. Secondary outcomes included total opioid consumption, discharge opioid consumption, pain scores (0-10) until discharge, adverse effects (respiratory depression, postoperative nausea and vomiting, excess sedation), and rate of admission. Seventy patients were randomly assigned. Patients who received methadone consumed on average 9.44 mg fewer oral morphine equivalents in the post-anaesthesia care unit than the short-acting group (18.02 mg vs 27.46 mg, respectively, 95% confidence interval 0.003 to 18.88, P = 0.050) and experienced lower postoperative pain scores at every time point, although absolute differences were small. There was no evidence of lower hospital or discharge opioid consumption. No significant differences between the methadone and short-acting groups in other outcomes were identified: respiratory depression 41.2% versus 31.4%, Padjusted >0.99; postoperative nausea and vomiting 29.4% versus 42.9%, Padjusted >0.99; overnight admission 17.7% versus 11.4%, Padjusted >0.99; excess sedation 8.82% versus 8.57%, Padjusted >0.99. This study provides evidence that, although modestly, methadone can reduce post-anaesthesia care unit opioid consumption and postoperative pain scores after day-case gynaecological laparoscopy. There were no significant differences in any secondary outcomes.

Self-reported intimate partner violence among men who have sex with men at an urban Australian sexual health clinic.

BACKGROUND: In Australia, 17% of women and 6% of men have experienced intimate partner violence (IPV). Although most IPV research has focused on heterosexual partnerships, studies suggest that men who have sex with men (MSM) may experience IPV at similar or higher rates than those documented among women. IPV may also take different forms among MSM and have different health and social impacts. This study aims to assess the utility of a screening tool for identifying and responding to IPV among MSM attending a sexual health clinic in Sydney, Australia. METHODS: Between 1 June 2020 and 30 June 2022, MSM clients were screened using standardised questions to identify IPV experienced within the preceding 12months. Answers to the screening questions were correlated with data collected routinely at the initial clinic visit, including age, employment, country of birth, drug and alcohol use, sexual partner numbers, and any history of sex work, pre-exposure prophylaxis use and HIV status, as well as any bacterial STI diagnosed at the initial visit. RESULTS: There were 2410 eligible clients and of these, 2167 (89.9%) were screened during the study period. A total of 64 men (3.0%) (95% CI 2.3-3.8%) reported experiencing physical violence or intimidation in the past 12months. Controlling for age, men who were born in Australia were 2.03 (95% CI: 1.04-3.01) times more likely to report IPV, and men who had Medicare were 2.43 (95% CI: 0.95-3.90) times more likely to report IPV than those who did not. Those who had ever injected drugs were 5.8 (95% CI: 1.87-9.73) times more likely to report IPV, and men with sexualised drug use were 4.11 (95% CI: 2.03-6.19) times more likely. Those that were employed or studying were 72% (95%CI: 0.13-0.42) less likely to report IPV. CONCLUSIONS: The prevalence of reported IPV in our study was lower than that reported by others, which may be due to differences in recruitment methods and questions asked. Associations between IPV in MSM and injecting drug use and sexualised drug use highlight that clinicians should be aware of the impact and potential for IPV particularly in those with risk factors.

What is the prevalence of orthostatic hypotension in an Australasian emergency department population?

OBJECTIVE: Orthostatic hypotension (OH) is associated with increased morbidity and there is limited research on the prevalence in the Australian ED population. The aim was to determine the prevalence of OH in an Australian ED population. Secondary outcomes included any associations of OH with symptoms, presenting complaints, patient demographics, or hospital admission, and the timing of OH findings. METHODS: Patients presenting to a regional Australasian ED underwent orthostatic measurements at 1, 3 and 5 min of standing following 5 min of supine bed rest. OH was defined as a drop in systolic and/or diastolic blood pressure by ≥20 and ≥10 mmHg, respectively. RESULTS: Of the 312 patients who were enrolled in the study, 69 (22.1%, 95% confidence interval 17.7-27.2%) had OH and 76.8% of cases were detected after 3 min of standing. There was evidence of difference in the prevalence of OH with age (P < 0.001). Similarly, there was evidence of a difference in supine systolic and diastolic blood pressure measurements (P = 0.012 and P < 0.001, respectively) between orthostatic and normotensive subjects. No association was found with OH and hospital admission, presenting complaints or comorbid medical illnesses. CONCLUSIONS: In this single Australian ED population, there was a high prevalence of OH (22.1%) with most cases detected within 3 min of standing. A higher-powered study across multiple sites would better substantiate these findings.

Human lower leg muscles grow asynchronously.

Muscle volume must increase substantially during childhood growth to generate the power required to propel the growing body. One unresolved but fundamental question about childhood muscle growth is whether muscles grow at equal rates; that is, if muscles grow in synchrony with each other. In this study, we used magnetic resonance imaging (MRI) and advances in artificial intelligence methods (deep learning) for medical image segmentation to investigate whether human lower leg muscles grow in synchrony. Muscle volumes were measured in 10 lower leg muscles in 208 typically developing children (eight infants aged less than 3 months and 200 children aged 5 to 15 years). We tested the hypothesis that human lower leg muscles grow synchronously by investigating whether the volume of individual lower leg muscles, expressed as a proportion of total lower leg muscle volume, remains constant with age. There were substantial age-related changes in the relative volume of most muscles in both boys and girls (p < 0.001). This was most evident between birth and five years of age but was still evident after five years. The medial gastrocnemius and soleus muscles, the largest muscles in infancy, grew faster than other muscles in the first five years. The findings demonstrate that muscles in the human lower leg grow asynchronously. This finding may assist early detection of atypical growth and allow targeted muscle-specific interventions to improve the quality of life, particularly for children with neuromotor conditions such as cerebral palsy.

Decreased rates of hospital-acquired infection after introduction of an active surveillance, virtual glucose management system.

Addition of an active surveillance virtual glucose management (VGM) system to usual consultation-based diabetes inpatient care at our hospital was associated with a decrease in hospital-acquired infection from 8.7% (17/196) to 3.5% (6/172) with an adjusted odds ratio of 0.17 (95%CI: 0.05-0.61), and a reduction in hypoglycemic and hyperglycemic patient-stay days.

Protolytic equilibria of ACE inhibitors in micellar solution of nonionic surfactant Brij 35.

The acid-base equilibria of six ACE inhibitors (ACEIs), captopril, cilazapril, enalapril, lisinopril, quinapril, and ramipril, were investigated in the presence of micelles of nonionic surfactant Brij 35. The pKa values were potentiometrically determined at 25 °C and at a constant ionic strength (0.1 M NaCl). The obtained potentiometric data were evaluated in the computer program Hyperquad. On the basis of the shift in the pKa values (ΔpKa) determined in micellar media in relation to the pKa values previously determined in "pure" water, the effect of Brij 35 micelles on ACEIs ionization was estimated. The presence of nonionic Brij 35 micelles caused a shift in the pKa values of all ionizable groups of the investigated ACEIs (ΔpKa from - 3.44 to + 1.9) while shifting the protolytic equilibria of both acidic and basic groups toward the molecular form. The Brij 35 micelles expressed the most pronounced effect on the ionization of captopril among the investigated ACEIs and stronger effect on the ionization of amino than on the ionization of carboxyl groups. The obtained results suggest that ionizable functional groups of ACEIs are involved in interactions with palisade layer of nonionic Brij 35 micelles, which potentially can be considered in physiological conditions. Distribution diagrams of the investigated ACEIs equilibrium forms as a function of pH indicate that the change in distribution is most strongly expressed in pH range 4-8, which includes biopharmaceutically important pH values.

CCNE1 and survival of patients with tubo-ovarian high-grade serous carcinoma: An Ovarian Tumor Tissue Analysis consortium study.

BACKGROUND: Cyclin E1 (CCNE1) is a potential predictive marker and therapeutic target in tubo-ovarian high-grade serous carcinoma (HGSC). Smaller studies have revealed unfavorable associations for CCNE1 amplification and CCNE1 overexpression with survival, but to date no large-scale, histotype-specific validation has been performed. The hypothesis was that high-level amplification of CCNE1 and CCNE1 overexpression, as well as a combination of the two, are linked to shorter overall survival in HGSC. METHODS: Within the Ovarian Tumor Tissue Analysis consortium, amplification status and protein level in 3029 HGSC cases and mRNA expression in 2419 samples were investigated. RESULTS: High-level amplification (>8 copies by chromogenic in situ hybridization) was found in 8.6% of HGSC and overexpression (>60% with at least 5% demonstrating strong intensity by immunohistochemistry) was found in 22.4%. CCNE1 high-level amplification and overexpression both were linked to shorter overall survival in multivariate survival analysis adjusted for age and stage, with hazard stratification by study (hazard ratio [HR], 1.26; 95% CI, 1.08-1.47, p = .034, and HR, 1.18; 95% CI, 1.05-1.32, p = .015, respectively). This was also true for cases with combined high-level amplification/overexpression (HR, 1.26; 95% CI, 1.09-1.47, p = .033). CCNE1 mRNA expression was not associated with overall survival (HR, 1.00 per 1-SD increase; 95% CI, 0.94-1.06; p = .58). CCNE1 high-level amplification is mutually exclusive with the presence of germline BRCA1/2 pathogenic variants and shows an inverse association to RB1 loss. CONCLUSION: This study provides large-scale validation that CCNE1 high-level amplification is associated with shorter survival, supporting its utility as a prognostic biomarker in HGSC.

MCM3 is a novel proliferation marker associated with longer survival for patients with tubo-ovarian high-grade serous carcinoma.

Tubo-ovarian high-grade serous carcinomas (HGSC) are highly proliferative neoplasms that generally respond well to platinum/taxane chemotherapy. We recently identified minichromosome maintenance complex component 3 (MCM3), which is involved in the initiation of DNA replication and proliferation, as a favorable prognostic marker in HGSC. Our objective was to further validate whether MCM3 mRNA expression and possibly MCM3 protein levels are associated with survival in patients with HGSC. MCM3 mRNA expression was measured using NanoString expression profiling on formalin-fixed and paraffin-embedded tissue (N = 2355 HGSC) and MCM3 protein expression was assessed by immunohistochemistry (N = 522 HGSC) and compared with Ki-67. Kaplan-Meier curves and the Cox proportional hazards model were used to estimate associations with survival. Among chemotherapy-naïve HGSC, higher MCM3 mRNA expression (one standard deviation increase in the score) was associated with longer overall survival (HR = 0.87, 95% CI 0.81-0.92, p < 0.0001, N = 1840) in multivariable analysis. MCM3 mRNA expression was highest in the HGSC C5.PRO molecular subtype, although no interaction was observed between MCM3, survival and molecular subtypes. MCM3 and Ki-67 protein levels were significantly lower after exposure to neoadjuvant chemotherapy compared to chemotherapy-naïve tumors: 37.0% versus 46.4% and 22.9% versus 34.2%, respectively. Among chemotherapy-naïve HGSC, high MCM3 protein levels were also associated with significantly longer disease-specific survival (HR = 0.52, 95% CI 0.36-0.74, p = 0.0003, N = 392) compared to cases with low MCM3 protein levels in multivariable analysis. MCM3 immunohistochemistry is a promising surrogate marker of proliferation in HGSC.

Serum concentrations of estriol vary widely after application of vaginal oestriol cream.

AIMS: The aim of this study was to establish the pharmacokinetic profile of serum oestriol (E3 ) concentrations over 24 h following application of vaginal E3 in chronic users (>12 weeks of E3 use). The interindividual and intraindividual differences before and after E3 were examined. METHODS: Ten women participated. Vaginal cream was omitted for ≥36 h prior to the study days. Blood sampling was performed for E3 , oestradiol and oestrone concentrations prior to cream application and at 1, 2, 3, 5, 8, 10, 12 and 24 h afterwards. In five women, all samples were repeated on a separate day. RESULTS: E3 was absorbed rapidly in most women. Peak serum E3 concentration occurred around 2 h (range 1-5 h). The decline in E3 concentrations was also rapid: falling <100 pmol L-1 in six out of ten women within 8 h and returning to ≤ 10 pmol L-1 at 24 h in nine out of the ten patients. Interindividual variability for peak concentrations was considerable (mean 546 pmol L-1 ; 95% CI 349-743). Area under the concentration-time curve (AUC) values over a dosage interval also varied widely: mean 2145 pmol.h L-1 ; 95% CI 1422-3233. However, repeated measurements in the same woman were highly (peaks: ρ = 0.94) or moderately (AUC: P = 0.74) correlated. CONCLUSIONS: Postmenopausal E3 concentrations are negligible. Serum E3 concentrations of chronic users of E3 cream varied greatly; however, concentrations declined rapidly within 8 h, generally reaching 'postmenopausal' levels by 24 h. The basis for the variation between subjects needs further elucidation. Additional research is required to establish the safety of topical E3 .

Systemic Anti-Cancer Therapy Use in Palliative Care Outpatients With Advanced Cancer.

PURPOSE: To evaluate factors associated with continuation of systemic anti-cancer therapy (SACT) after palliative care consultation, and SACT administration in the last 30 days of life, in outpatients with cancer referred to palliative care. Timing of referral was of particular interest. METHODS: Patient, disease, and treatment-related factors associated with SACT before and after palliative care, and in the last 30 days of life, were identified using 3-level multinomial logistic regression. Referral to palliative care was categorized by time from death as early (>12 months), intermediate (6-12 months), and late (≤6 months). RESULTS: Of the 337 patients, 240 (71.2%) received SACT for advanced cancer; of these, 126 (52.5%) received SACT only prior to palliative care while 114 (47.5%) also received SACT afterward. Only 35/337 (10.4%) received SACT in the last 30 days of life. On multivariable analysis, factors associated with continuing SACT after palliative care consultation were a cancer diagnosis for <1 year (OR 3.09, p = 0.01), breast primary (OR 11.88, p = 0.0008), and early (OR 28.8, p < 0.001) or intermediate (OR 6.67, p < 0.001) referral timing. No factors were significantly associated with receiving SACT in the last 30 days versus earlier, but the median time from palliative care referral to death in those receiving SACT in the last 30 days versus stopping SACT earlier was 1.78 versus 4.27 months. CONCLUSION: Patients who received SACT following palliative care consultation were more likely to be referred early; however, patients receiving SACT in their last 30 days tended to be referred late.

Pain in patients with newly diagnosed or relapsed acute leukemia.

PURPOSE: Acute leukemia (AL) is associated with substantial morbidity and mortality. We assessed the prevalence and correlates of pain in patients with newly diagnosed or relapsed AL. METHODS: Patients with newly diagnosed or relapsed AL admitted to a comprehensive cancer center completed the Memorial Symptom Assessment Scale (MSAS), which assesses prevalence, severity, and distress associated with pain and other symptoms. Factors associated with severe pain were assessed using logistic regression. Two raters completed chart reviews in duplicate for patients with severe pain (MSAS severity ≥ 3/4) to determine the site of pain. RESULTS: Three hundred eighteen patients were recruited from January 2008 to October 2013: 245 (77.0%) had acute myeloid or acute promyelocytic leukemia (AML/APL) and 73 (23.0%) had acute lymphoblastic leukemia (ALL); 289 (90.9%) were newly diagnosed and 29 (9.1%) had relapsed disease. Pain was reported in 156/318 (49.2%), of whom 55/156 (35.3%) reported severe pain (≥ 3/4). Pain was associated with all psychological symptoms (all p < 0.005) and some physical symptoms. Severe pain was associated with younger age (p = 0.02), worse performance status (p = 0.04), ALL diagnosis (p = 0.04), and time from onset of chemotherapy (p = 0.03), with pain peaking at 4 weeks after chemotherapy initiation. The most common sites of severe pain were oropharynx (22; 40%), head (12; 21.8%), and abdomen (11; 20%). Only 3 patients (0.9%) were referred to the symptom control/palliative care team during the month prior to or following assessment. CONCLUSIONS: Pain is frequent, distressing, and predictable in patients undergoing induction chemotherapy for AL. Further research is needed to assess the efficacy of early supportive care in this population.

Antipsychotic Deprescription for Older Adults in Long-term Care: The HALT Study.

OBJECTIVES: Despite limited efficacy and significant safety concerns, antipsychotic medications are frequently used to treat behavioral and psychological symptoms of dementia (BPSD) in long-term residential care. This study evaluates the sustained reduction of antipsychotic use for BPSD through a deprescribing intervention and education of health care professionals. DESIGN: Repeated-measures, longitudinal, single-arm study. SETTING: Long-term residential care of older adults. PARTICIPANTS: Nursing staff from 23 nursing homes recruited 139 residents taking regular antipsychotic medication for ≥3 months, without primary psychotic illness, such as schizophrenia or bipolar disorder, or severe BPSD. INTERVENTION: An antipsychotic deprescribing protocol was established. Education of general practitioners, pharmacists, and residential care nurses focused on nonpharmacological prevention and management of BPSD. MEASUREMENTS: The primary outcome was antipsychotic use over 12-month follow-up; secondary outcomes were BPSD (Neuropsychiatric Inventory, Cohen-Mansfield Agitation Inventory, and social withdrawal) and adverse outcomes (falls, hospitalizations, and cognitive decline). RESULTS: The number of older adults on regular antipsychotics over 12 months reduced by 81.7% (95% confidence interval: 72.4-89.0). Withdrawal was not accompanied by drug substitution or a significant increase in pro-re-nata antipsychotic or benzodiazepine administration. There was no change in BPSD or in adverse outcomes. CONCLUSION: In a selected sample of older adults living in long-term residential care, sustained reduction in regular antipsychotic use is feasible without an increase of BPSD.

А theoretical study on ionization of sartans in aqueous media and on interactions with surfactant micelles.

The ionization order of sartans in aqueous media and possible way of interactions between their equilibrium forms and surfactant micelles have been theoretically investigated. The examined sartans are ampholytes (irbesartan and losartan) and a diacid (valsartan) with the close values of ionization constants. In order to get a better insight in the overlapped protolytic equilibria of sartans and to predict an affinity of the equilibrium forms interacting with micelles as biomembrane mimetic systems, the theoretical study was performed. Energy calculation of the optimized structures of the equilibrium forms was performed at the B3LYP/6-31G (d,p) level of the Density Functional Theory (DFT). The results of the theoretical study helped to assign the experimentally determined pKa values to the corresponding ionizable centers and confirmed that in all examined compounds, the higher pKa values can be attributed to ionization of tetrazole. The molecular descriptor values showed that sartans interact predominantly with the micelle surfaces. The equilibrium forms of ampholytes demonstrate higher affinity to the micelles, as compared to the forms of the diprotic acid. Additionally, it was shown that the uncharged molecular forms of ampholytes are more lipophylic then their zwitterionic forms.

Factors Associated with Early Referral to Palliative Care in Outpatients with Advanced Cancer.

BACKGROUND: Although timely palliative care is recommended for patients with advanced cancer, referrals to palliative care services are often late. OBJECTIVES: To identify factors associated with early referral to an oncology palliative care clinic and to describe symptom severity according to timing of referral. DESIGN: We conducted a retrospective review of 337 patients with advanced cancer referred to outpatient palliative care at a comprehensive cancer center. We gathered data related to patient demographics, diagnosis, and referral. Timing of referral was categorized as early (>12 months before death), intermediate (6-12 months before death), or late (<6 months before death). Ordinal logistic regression was used to determine factors related to referral timing, and the Kruskal-Wallis test to determine symptom severity in each referral timing category. RESULTS: Of the 337 patients, 232 (69%) referrals were late, 60 (18%) intermediate, and 45 (13%) early. On multivariable analysis, earlier referral was associated with earlier primary cancer diagnosis (p = 0.004), and referral for pain and symptom management (p = 0.001). Patients who were referred late had worse overall Edmonton Symptom Assessment System distress scores, as well as worse tiredness, nausea, drowsiness, appetite, and wellbeing (all p ≤ 0.001). Severity of pain, shortness of breath, anxiety, and depression did not differ based on time of referral. CONCLUSIONS: A longer disease course and referral for symptom management were associated with earlier referral, whereas overall symptom burden was higher for late referrals. Further research is required on combining symptom screening with timely referral to improve symptom management in advanced cancer.

Patient-Reported Functional Status in Outpatients With Advanced Cancer: Correlation With Physician-Reported Scores and Survival.

CONTEXT: Performance status measures are increasingly completed by patients in outpatient cancer settings, but are not well validated for this use. OBJECTIVES: We assessed performance of a patient-reported functional status measure (PRFS, based on the Eastern Cooperative Oncology Group [ECOG]), compared with the physician-completed ECOG, in terms of agreement in ratings and prediction of survival. METHODS: Patients and physicians independently completed five-point PRFS (lay version of ECOG) and ECOG measures on first consultation at an oncology palliative care clinic. We assessed agreement between PRFS and ECOG using weighted Kappa statistics, and used linear regression to determine factors associated with the difference between PRFS and ECOG ratings. We used the Kaplan-Meier method to estimate the patients' median survival, categorized by PRFS and ECOG, and assessed predictive accuracy of these measures using the C-statistic. RESULTS: For the 949 patients, there was moderate agreement between PRFS and ECOG (weighted Kappa 0.32; 95% CI: 0.28-0.36). On average, patients' ratings of performance status were worse by 0.31 points (95% CI: 0.25-0.37, P < 0.0001); this tendency was greater for younger patients (P = 0.002) and those with worse symptoms (P < 0.0001). Both PRFS and ECOG scores correlated well with overall survival; the C-statistic was higher for the average of PRFS and ECOG scores (0.619) than when reported individually (0.596 and 0.604, respectively). CONCLUSION: Patients tend to rate their performance status worse than physicians, particularly if they are younger or have greater symptom burden. Prognostic ability of performance status could be improved by using the average of patients and physician scores.

Protolytic Equilibria of Sartans in Micellar Solutions of Differently Charged Surfactants.

Protolytic equilibria of irbesartan, losartan, and valsartan have been investigated in the presence and absence of differently charged anionic (sodium dodecyl sulfate), cationic (cetyltrimethylammonium bromide), and nonionic (4-octylphenol polyethoxylate and polyoxyethylene (23) lauryl ether) surfactants. Ionization constants were determined by potentiometric titration at a constant ionic strength (0.1 M NaCl) and temperature 25°C. The effect of surfactants was estimated, based on a shift in apparent ionization constants (pKa(app)) determined in micellar solutions against the pKa(w) values in water. The anionic surfactant caused an increase in the pKa(app) values of sartans (up to 1.72 pK units), while the cationic surfactant had an opposite effect and caused a reduction in pKa(app) values (up to -1.44 pK units). These results point out to the fact that the ionizable groups of sartans are involved in electrostatic interactions with the charged surface of the ionic micelles. Shift in the pKa(app) values in the presence of nonionic surfactants (from -0.86 to +1.30) is a consequence of the interactions of drugs with the hydrophilic palisade layer. Significant changes in the distribution profiles of the equilibrium forms (from -44% to +80%) are observed at the biopharmaceutically important pH 4.5 value and can be considered in terms of the potential influence on intestinal absorption and bioavailability.

Arteriovenous fistula aneurysm in patients on regular hemodialysis: prevalence and risk factors.

BACKGROUND/AIMS: Compared to all other complications, literature data about vascular access aneurysm (VAA) are the scarcest. The aim of this cross-sectional study was to evaluate the prevalence of arteriovenous fistula (AVF) aneurysms and to confirm the risk factors for their appearance. METHODS: The presence, number and morphological characteristics of AVF aneurysms were confirmed, and according to the score of AVF aneurysm (the sum of the length and width in cm), patients were classified into group 1 (score ≤12) and group 2 (score >12). Analysis included the last data from the medical records including vascular calcifications score. RESULTS: Out of 181 patients, 150 with native fistula were included in this study. Aneurysmatic changes were detected in 90 (60%) patients, and the majority had two or more aneurysms. VAA were more frequent in patients with adult polycystic kidney disease (ADPKD) than in other diagnostic categories. By using forward stepwise logistic regression, we confirmed that patients on high-flux hemodialysis (HD) had 5.3-fold higher risk, and patients with diabetes mellitus had 5.8-fold less risk for developing AVF aneurysm. While vascular calcification score did not influence the incidence of VAA, higher PWV had significant negative influence on formation of AVF aneurysm (OR 1.25, 95% CI 1.003-1.56, p = 0.047). By ROC curve analysis, it was determined that patients who were longer than 5.7 years on HD had greater risk for developing VAA (area = 0.741, p = 0.000). CONCLUSION: This single-center study confirmed the very high prevalence of VAA (60%). Aneurysms were more frequent in patients with ADPKD and in those who had longer dialysis vintage on high-flux membranes with higher blood flow rate.

Ultra-thin-layer chromatography mass spectrometry and thin-layer chromatography mass spectrometry of single peptides of angiotensin-converting enzyme inhibitors.

The separation of structurally related angiotensin-converting enzyme (ACE) inhibitors lisinopril, cilazapril, ramipril and quinapril and their corresponding active diacid forms (prilates) by conventional TLC silica gel 60 plates was contrasted with that afforded by monolithic ultra-thin-layer chromatographic (UTLC) plates. For the use of UTLC plates technical modifications of the commercially available equipments for the sample application, development and detection were made. Plates were developed in modified horizontal developing chamber using ethyl acetate-acetone-acetic acid-water (4:1:0.25:0.5, v/v). Detection of the separated compounds was performed densitometrically in absorption/reflectance mode at 220 nm and after exposure to iodine also by image analysis. The obtained results showed that monolithic layer is more efficient for the separation of structurally similar polar compounds, such as prilates than conventional silica layers. Identification of the compounds was confirmed by ESI-MS after their on-line extraction from the UTLC and TLC plates by means of Camag TLC-MS interface.

Acid-base equilibria and solubility of loratadine and desloratadine in water and micellar media.

Acid-base equilibria in homogeneous and heterogeneous systems of two antihistaminics, loratadine and desloratadine were studied spectrophotometrically in Britton-Robinson's buffer at 25 degrees C. Acidity constant of loratadine was found to be pK(a) 5.25 and those of desloratadine pK(a1) 4.41 and pK(a2) 9.97. The values of intrinsic solubilities of loratadine and desloratadine were 8.65x10(-6) M and 3.82x10(-4) M, respectively. Based on the pK(a) values and intrinsic solubilities, solubility curves of these two drugs as a function of pH were calculated. The effects of anionic, cationic and non-ionic surfactants applied in the concentration exceeding critical micelle concentration (cmc) on acid-base properties of loratadine and desloratadine, as well as on intrinsic solubility of loratadine were also examined. The results revealed a shift of pK(a) values in micellar media comparing to the values obtained in water. These shifts (DeltapK(a)) ranged from -2.24 to +1.24.