Relationship between insomnia and pain in patients with chronic orofacial pain

OBJECTIVE

Few studies have investigated specific associations between insomnia and orofacial pain (OFP). The aim of this cross-sectional study was to examine relationships of insomnia with pain, mental health, and physical health variables among treatment-seeking patients with chronic OFP.

METHODS

OFP diagnosis, demographics, insomnia symptoms, pain intensity, interference, and duration, mental health measures, and number of medical comorbidities were extracted from the medical records of 450 patients receiving an initial appointment at a university-affiliated tertiary OFP clinic. T-tests compared differences between patients with and without insomnia symptomatology, and between patients with different insomnia subtypes (delayed onset/early wakening).

RESULTS

Compared to patients without insomnia, those with elevated insomnia symptomatology (45.1%) reported higher pain intensity (60.70 ± 20.61 vs 44.15 ± 21.69; P < .001) and interference (43.81 ± 29.84 vs 18.40 ± 23.43; P < 0.001), depression/anxiety symptomatology (5.53 ± 3.32 vs 2.72 ± 2.66; P < 0.001), dissatisfaction with life (21.63 ± 6.95 vs 26.50 ± 6.21; P < .001), and number of medical comorbidities (6.72 ± 5.37 vs 4.37 ± 4.60; P < .001). Patients with Sleep Onset Latency insomnia (SOL-insomnia) (N = 76) reported higher pain intensity (t = 3.57; P < 0.001), and pain interference (t = 4.46; P < .001) compared to those without SOL-insomnia. Those with Early Morning Awakening insomnia (EMA-insomnia) (N = 71) did not significantly differ from those without EMA-insomnia on any of the variables. Differences remained significant after adjusting for age, sex, primary OFP diagnosis, and pain intensity.

CONCLUSIONS

Insomnia is associated with pain outcomes and should be appropriately managed when treating patients with chronic OFP.

Social health in young women with chronic pain

Introduction

Chronic pain may negatively affect social functioning, but no study to date has examined the specific social impact of different chronic pain conditions in young women, and whether living with multiple chronic overlapping pain conditions (COPCs) differently influences social domains.

Objectives

This study aimed to assess social functioning (social isolation, hostility, informational support satisfaction, social roles, emotional support, friendships, and family relationships) among young women with chronic pain compared with pain-free controls and to test whether the number of COPCs influenced the extent of social burden.

Methods

Participants aged 18 to 30 years with a physician-confirmed diagnoses of migraine, fibromyalgia, or temporomandibular disorder (TMD) and pain-free controls were invited to participate from across the United States. After confirming eligibility, participants completed a 1-hour REDCap online questionnaire assessing social functioning.

Results

One hundred four participants (mean age 24.54 ± 3.35 years) were included (n = 26 with TMD, n = 25 with fibromyalgia, n = 25 with migraine, and n = 28 controls). All 3 chronic pain groups combined reported worse functioning than controls on friendship (P = 0.038), social isolation (P = 0.002), and social roles (P < 0.001). There were no differences on social variables between the 3 chronic pain groups (all P's > 0.05). Compared with those with 3 COPCs, participants with 1 condition reported better family relationships (P = 0.024).

Conclusions

Experience of chronic pain-regardless of the specific pain condition-may negatively affect some areas of social functioning in young women.

Evolution of adherence and self-reported symptoms over 36 months with mandibular advancement device therapy for obstructive sleep apnea: a retrospective study

STUDY OBJECTIVES

Mandibular advancement devices (MAD) constitute a feasible option for management of mild-to-moderate obstructive sleep apnea (OSA) and in severe cases, when indicated. As a chronic condition, the management of OSA with MAD requires long-term patient adherence to treatment. The aim of the study was to investigate adherence to MAD therapy during a 36-month observation period in relation to changes in self-reported symptoms and objective response to therapy.

METHODS

Retrospective chart review of patients referred to the Orofacial Pain Clinic (University of Kentucky) between 2016 and 2021 for management of OSA with MAD was performed. Based on a posttreatment sleep study with MAD in situ, participants were subdivided into optimal response (> 50% reduction of baseline apnea-hypopnea index) and suboptimal response (< 50% reduction of baseline apnea-hypopnea index) groups. Outcomes included self-reported adherence to MAD use, self-reported OSA symptoms including snoring, apneic episodes, tiredness upon awakening, fatigue, and sleep quality (on a 100-mm numerical rating scale), and daytime sleepiness (0-24 on the Epworth Sleepiness Scale). Intragroup and intergroup differences at different time points over a 36-month observation period were assessed with one-way and repeated-measures analysis of variance.

RESULTS

Of 54 participants included (46.3% female, age 64.4 ± 10.71 years), 30 (55.6%) achieved optimal response and 24 (44.4%) achieved suboptimal response. At baseline, participants with optimal response differed from those with suboptimal response in apnea-hypopnea index (P = .007), snoring (P = .026), and sleep quality (P = .042). Although fluctuating in both groups, no difference was found over time in adherence (7 nights/wk, 7 h/night) and in OSA symptoms (all P > .05).

CONCLUSIONS

Adherence to MAD was maintained over 36 months regardless of fluctuation in self-reported OSA symptoms and effectiveness of MAD therapy.

CITATION

Sangalli L, Yanez-Regonesi F, Moreno-Hay I. Evolution of adherence and self-reported symptoms over 36 months with mandibular advancement device therapy for obstructive sleep apnea: a retrospective study. J Clin Sleep Med. 2024;20(4):487-496.

Malocclusions, Sleep Bruxism, and Obstructive Sleep Apnea Risk in Pediatric ADHD Patients: A Prospective Study

OBJECTIVES

Literature presents conflicting results regarding malocclusions, Obstructive Sleep Apnea (OSA) and sleep bruxism in children with ADHD. Aim of this study was to evaluate the prevalence of these parameters.

METHODS

A prospective study was conducted on 40 consecutive ADHD children referred to the Paediatric Dentistry Unit of Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Rome. All subjects underwent an orthodontic examination and were screened for OSA and sleep bruxism. Data were compared to a sex- and aged-matched control group.

RESULTS

Prevalence of high risk of OSA in children with ADHD was 62.5% compared to 10% in the control group (p < .00001). No differences were found in any of the occlusal variables examined between children with ADHD and controls (p > .05). An increased prevalence of sleep bruxism was observed in ADHD children (40%) compared to controls (7.5%) (p < .001).

CONCLUSIONS

A higher prevalence of OSA risk and probable sleep bruxism were observed in ADHD patients compared with controls. No significant differences were observed in malocclusions d.

Sleep bruxism: The past, the present, and the future-evolution of a concept

BACKGROUND

The concept of sleep bruxism (SB) has evolved exponentially over the past several decades. Many theories and hypotheses have been proposed as to the definition, pathophysiology, and management of SB, from the early 1960s through the present. The role of peripheral factors, such as dental occlusion, in the pathogenesis of SB has been discarded.

TYPES OF STUDIES REVIEWED

The authors searched several electronic databases (ie, PubMed, Google Scholar, Web of Science, Embase, and Ovid MEDLINE) for studies on bruxism. The search was conducted from January 1961 through May 2023 and yielded 4,612 articles, of which 312 were selected for comprehensive review after eliminating duplicates and nonfocused articles.

RESULTS

There has been an evident progressive shift from the role of peripheral factors, such as dental occlusion, to more central factors, such as the involvement of a central pattern generator as well as the autonomic nervous system, in the genesis of bruxing movements. There is continued robust interest in the dental community to elucidate the contributing factors involved in SB.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

The neurophysiology of SB appears to be leaning more toward central rather than peripheral factors. There is increasing evidence of the role of the autonomic nervous system, genetics, and comorbidities in the genesis of SB. The scientific literature seems to refute the role of dental occlusion in the causation of bruxing movements. As per the literature, there has been a paradigm shift in the definition and genesis of SB and its possible dental implications and management, which also highlights the need for succinct scientific studies in this regard.

A review of animal models for burning mouth syndrome: Mechanistic insights and knowledge gaps

OBJECTIVES

The underlying mechanisms of burning mouth syndrome (BMS) remain unclear leading to challenges and unsatisfactory management. Current treatments focus primarily on symptom relief, with few consistently achieving a 50% reduction in pain. This review aims to explore animal models of BMS to gain a better understanding of the underlying mechanisms and to discuss potential and existing knowledge gaps.

METHODS

A comprehensive review of PubMed® , Google Scholar, and Scopus was performed to assess advances and significant gaps of existing rodent models that mimic BMS-related symptoms.

RESULTS

Rodent models of BMS involve reproduction of dry-tongue, chorda tympani transection, or overexpression of artemin protein. Existing preclinical models tend to highlight one specific etiopathogenesis and often overlook sex- and hormone-specific factors.

CONCLUSION

Combining aspects from various BMS models could prove beneficial in developing comprehensive experimental designs and outcomes encompassing the multifaceted nature of BMS.

Effectiveness of dental monitoring system in orthodontics: A systematic review

BACKGROUND

Dental monitoring (DM) constitutes a recent technological advance for the remote monitoring of patients undergoing an orthodontic therapy. Especially in times of health emergency crisis, the possibility of relying on remote monitoring could be particularly useful.

OBJECTIVES

To assess the effectiveness of DM in orthodontic care.

ELIGIBILITY

Studies conducted on healthy patients undergoing orthodontic care where DM was applied, assessing a change in treatment duration, emergency appointments, in-office visits, orthodontic relapse, early detection of orthodontic emergencies and improvement of oral health status.

INFORMATION SOURCES

PubMed, Web of Science and Scopus were searched for publications until November 2022.

RISK OF BIAS

Quality assessment was performed with the STROBE Checklist.

DATA EXTRACTION

Data were extracted independently by two reviewers, and discrepancies were resolved with a third reviewer.

INCLUDED STUDIES

Out of 6887 records screened, 11 studies were included.

SYNTHESIS OF RESULTS

DM implemented to the standard orthodontic care was found to significantly decrease the number of in-office visits by 1.68-3.5 visits and showed a possible trend towards improvement of aligner fit. Conversely, evidence does not support a reduction of treatment duration and emergency appointments. The assessment of the remaining variables did not allow any qualitative synthesis.

CONCLUSIONS

This review highlighted that DM implemented to standard orthodontic care can significantly decrease the number of in-office visits and may potentially result in an improved aligner fit. Due to the low quality of most of the included studies and the heterogeneity of the orthodontic system where DM was applied, studies with different investigation team and rigorous methodology are advocated.

Impact of Concurrent Use of N95 and Surgical Masks on Peripheral Oxygen Saturation and Heart Rate Frequency-A Prospective Study during the COVID-19 Outbreak

Background and Objectives: The COVID-19 outbreak has necessitated the prolonged use of N95 facemasks in addition to traditional surgical facemasks by healthcare workers. The aim of this study was to investigate the effect of wearing N95 facemasks in addition to surgical facemasks on peripheral oxygen saturation (SpO2) and heart rate (HR) among dental professionals during routine care. Materials and Methods: This prospective study compared SpO2 and HR between dental providers wearing N95 + surgical facemasks vs. wearing a surgical facemask only. SpO2 and HR were recorded using a portable pulse oximeter before wearing the facemask (T0); at 30 min (T1); at 1 h (T2); and at the end of clinical activity (T3). Inter-group and intra-group differences were assessed with independent t tests and repeated measures ANOVA, respectively. Results: A total of 88 participants (57 wearing N95 + surgical facemasks, and 31 wearing a surgical facemask only) completed the study. The two groups did not statistically differ in SpO2 at different timepoints nor showed any intra-group differences. The participants wearing N95 + surgical facemasks exhibited a statistically higher HR at T0 (p = 0.007), T2 (p = 0.010), and T3 (p = 0.014) compared to those wearing a surgical facemask only. A statistically significant decrease was observed in HR between T0 and T3 in those wearing N95 + surgical facemasks (p = 0.012). No intra-group differences were seen in HR over time in those wearing a surgical facemask only. Conclusions: The continuous use of an N95 in addition to a surgical facemask did not show any significant effects in SpO2 during routine care; however, the concurrent use of an N95 and a surgical facemask seemed to be accompanied by a decrease in HR, although the values remained within the normal range.

The relationship between possible, probable, or definite sleep bruxism and sleep quality: A systematic review

It has been suggested that sleep bruxism may interrupt sleep continuity, hence potentially influencing sleep quality. The aim of this study was to systematically review the relationship between possible, probable, and definite sleep bruxism and sleep quality in otherwise healthy individuals. A systematic search on sleep bruxism and sleep quality was performed in seven databases until 19 December 2022. Eligible articles were screened, and quality assessment was performed via the Joanna Briggs Institute Scale. Of 3681 articles screened, 13 were included in this study. Of these, six evaluated the relationship between sleep quality and possible sleep bruxism, three with probable sleep bruxism, and four with definite sleep bruxism. An association between poor sleep quality and sleep bruxism was found among those individuals diagnosed with possible and probable sleep bruxism. However, the studies conducted in individuals with definite sleep bruxism failed to demonstrate any association. With more reliable measures to evaluate sleep bruxism, a relationship between sleep bruxism and sleep quality was not evident.

Leveraging machine learning to create user-friendly models to mitigate appointment failure at dental school clinics

PURPOSE/OBJECTIVES

This study had a twofold outcome. The first aim was to develop an efficient, machine learning (ML) model using data from a dental school clinic (DSC) electronic health record (EHR). This model identified patients with a high likelihood of failing an appointment and provided a user-friendly system with a rating score that would alert clinicians and administrators of patients at high risk of no-show appointments. The second aim was to identify key factors with ML modeling that contributed to patient no-show appointments.

METHODS

Using de-identified data from a DSC EHR, eight ML algorithms were evaluated: simple decision tree, bagging regressor classifier, random forest classifier, gradient boosted regression, AdaBoost regression, XGBoost regression, neural network, and logistic regression classifier. The performance of each model was assessed using a confusion matrix with different threshold level of probability; precision, recall and predicted accuracy on each threshold; receiver-operating characteristic curve (ROC) and area under curve (AUC); as well as F1 score.

RESULTS

The ML models agreed on the threshold of probability score at 0.20-0.25 with Bagging classifier as the model that performed best with a F1 score of 0.41 and AUC of 0.76. Results showed a strong correlation between appointment failure and appointment confirmation, patient's age, number of visits before the appointment, total number of prior failed appointments, appointment lead time, as well as the patient's total number of medical alerts.

CONCLUSIONS

Altogether, the implementation of this user-friendly ML model can improve DSC workflow, benefiting dental students learning outcomes and optimizing personalized patient care.

Sex as a Biological Variable in Oral Diseases: Evidence and Future Prospects

The interest of the scientific community on sex and gender differences in health and disease has increased substantially over the past 25 to 30 y as a result of a long process of events and policies in the biomedical field. This is crucial as compelling evidence from human and animal model studies has demonstrated that sex and gender influence health, molecular and cellular processes, and response and predisposition to disease. The present scoping review aims to provide a synthesis of sex differences in oral diseases, ranging from periodontal disease to orofacial pain conditions, from risk of caries development to apical periodontitis. Overall, findings from this review further support a role for sexual dimorphism influencing disease predisposition and/or progression in oral diseases. Of note, this review also highlights the lack of consideration of additional factors such as gender and other psychosocial and external factors potentially influencing oral health and disease. New conceptual frameworks capable of capturing multiple fundamental domains and measurements should be developed in clinical and preclinical studies to inform sex-based individualized preventive and treatment strategies.

Occupations associated with treatment seeking and biopsychosocial functioning at a tertiary orofacial pain clinic: A cross-sectional study

BACKGROUND

The aim of this study was to describe whether certain occupations were over- or underrepresented and to compare biopsychosocial functioning by types of occupation and employment status among adults seeking orofacial pain (OFP) treatment.

METHODS

The authors extracted self-reported employment status, occupation, and biopsychosocial functioning from initial appointment records of 444 treatment-seeking adults at a university-affiliated OFP clinic. The authors categorized occupations in major and minor occupational groups according to the 2018 Standard Occupational Classification. The authors compared proportions between their sample and the corresponding state level, using a ratio and 95% CI (1.00 = equal representation in sample vs state, < 1.00 = underrepresentation, > 1.00 = overrepresentation).

RESULTS

Among major occupational categories, health care practitioners and technical occupations were the most common in the study sample (22.4%) and the second most overrepresented (ratio, 3.20; 95% CI, 2.59 to 3.97) after the arts, design, entertainment, sports, and media occupations (ratio, 3.95; 95% CI, 2.15 to 7.26). Among minor occupational categories, teachers and instructors were the most common in the study sample (11.2%) and the most overrepresented (ratio, 90.71; 95% CI, 65.67 to 125.30), followed by managers (ratio, 43.87; 95% CI, 29.61 to 64.99) and photographers (ratio, 40.89; 95% CI, 10.23 to 163.4). No differences were observed in biopsychosocial functioning between major occupational categories. However, those not working due to health reasons or disability had worse biopsychosocial functioning (insomnia, anxiety and depression, life satisfaction, sleep health, pain intensity, pain-related interference; all P < .034) than those who were employed.

CONCLUSIONS

Several occupations are strongly over- and underrepresented among adults seeking OFP treatment. Differences were not explained by biopsychosocial functioning.

PRACTICAL IMPLICATIONS

Future research should attempt to identify and address the underlying mechanisms of association between occupation and seeking care for OFP.

Assessment of dental ergonomics among dental students: A retrospective study

INTRODUCTION

Musculoskeletal (MSK) disorders account for 11%-98% of occupational health issues for dental professionals, with an onset as early as in dental school. Dental ergonomics is among the risk factors; thus, a prompt assessment is crucial in preventing future MSK pain. The aim of this study was to retrospectively assess dental ergonomics of second-year dental students after dedicated lectures were introduced in the predoctoral curriculum.

METHODS

Three cohorts of second-year dental students were evaluated during preclinical activity in July 2019, January 2022, and December 2022 by an Occupational Therapy (OT) faculty and calibrated OT students. Dental ergonomics was assessed with the Rapid Upper Limb Assessment (RULA). Dental student cohorts were compared with one-way analysis of variance (ANOVA).

RESULTS

The average RULA final score of 409 participants was 5.1 ± 0.9, with no difference between the three cohorts (p = 0.676). The January 2022 cohort scored significantly lower in wrist-arm score than that of 2019 (p = 0.001) and December 2022 (p = 0.046). Neck and lower limb posture were significantly higher in January 2022 cohort than in 2019 (p = 0.001 and 0.013) and December 2022 (p = 0.001 and 0.005) cohorts. The December 2022 cohort revealed a medium, high and extremely high risk of developing MSK of 40.2%, 37.1%, and 21.6%, respectively, with no difference between sexes.

CONCLUSION

The risk of developing MSK pain was medium-high in predoctoral dental students and was not related to sex. The overall dental ergonomics required attention and rapid change. Further implementation of varied forms of teaching and monitoring of dental ergonomics from the early years of education is recommended to prevent development of MSK pain at young age and foster better postural habits.

Prevalence of Malocclusions in Down Syndrome Population: A Cross-Sectional Study

Background and Objectives: A higher prevalence of dental malocclusion has been suggested among individuals with Down Syndrome (DS) compared to controls, although no studies to date have investigated such a difference according to age group. Therefore, the aim of this study was to compare the prevalence of dental malocclusion and other orthodontic measures between DS and non-syndromic (non-DS) individuals across three age groups of children, adolescents, and adults. Materials and Methods: This cross-sectional study was conducted on a total of 147 patients. Of those, 72 were diagnosed with DS and were divided into N = 15 children (<10 years), N = 23 adolescents (10-18 years) and N = 34 adults (>18 years). The remaining 75 patients were sex- and age-matched controls. The two groups were compared according to age group in terms of the prevalence of dental malocclusion, measures of sagittal, vertical, and transverse discrepancy, facial profile, and probable sleep bruxism with chi-square tests for proportion. Results: The DS patients consistently exhibited a higher prevalence of Class 3 malocclusion, concave profile and anterior crossbite compared to the non-DS patients, regardless of age group. The non-DS adolescents presented with a significantly higher prevalence of convex profile than the DS adolescents. The adolescent and adult DS patients most commonly presented with a maxillary transverse discrepancy and posterior crossbite compared to the non-DS controls. The DS adults had a higher prevalence of probable sleep bruxism. Conclusions: Patients with DS showed a higher prevalence of Class 3 malocclusion, concave profile and anterior crossbite compared to non-DS controls, regardless of age group. Other orthodontic measures showed a fluctuation according to the age group considered.

Self-reported improvement in obstructive sleep apnea symptoms compared to treatment response with mandibular advancement device therapy: a retrospective study

PURPOSE

Mandibular advancement device (MAD) is recognized as the treatment option for management of obstructive sleep apnea (OSA) in mild-moderate cases or those unable to tolerate positive airway pressure therapy. Post-treatment sleep study is recommended to establish MAD efficacy when maximal therapeutic benefit is achieved based on OSA symptom improvement or maximum anatomical protrusion. The aim of this study was to investigate the difference between responders and non-responders in OSA symptom improvement and predictors of treatment success.

METHODS

Medical charts of patients referred to the Orofacial Pain Clinic between 2016 and 2021 for management of OSA with MAD were retrospectively evaluated. Participants with post-treatment sleep study with MAD in situ were included. Participants were categorized as responders according to different criteria: 50% reduction in apnea-hypopnea index (AHI) compared to baseline; post-treatment AHI ≤ 10 with ≥ 50% reduction from baseline; AHI ≤ 5 with ≥ 50% reduction. OSA symptoms included snoring, apneas, sleep quality, tiredness upon awakening, daytime sleepiness, and subjective improvement. Differences in pre- and post-treatment variables within/between groups and predictors were analyzed with t test and logistic regression.

RESULTS

Among 53 participants (30 females), mean age was 64.2 ± 10.7 and pre-treatment was AHI 23.3 ± 17.2. Depending upon the criteria, responders ranged between 26 and 57%. At first follow-up after MAD delivery, non-responders reported less tiredness upon awakening (p = 0.003), better sleep quality (p = 0.005), and greater subjective improvement (p = 0.012) than responders. Among significant OSA symptoms, tiredness upon awakening, poorer sleep quality, and less subjective improvement were consistently found as predictors of treatment response.

CONCLUSION

Subjective improvement, sleep quality, and tiredness upon awakening significantly improved in non-responders at first follow-up compared to responders, according to the strictest definition of treatment response. Therefore, a post-treatment sleep study is crucial to confirm proper management of OSA with MAD.

Calcitonin Gene-Related Peptide-Mediated Trigeminal Ganglionitis: The Biomolecular Link between Temporomandibular Disorders and Chronic Headaches

A bidirectional causal relationship has been established between temporomandibular disorders (TMDs) and chronic headaches. Recent advances in the neurobiology of chronic pain offer a framework for understanding the comorbidity between these two conditions that might reside in the shared biomolecular mechanisms of peripheral and central sensitization. The initiation of these processes is inflammatory in nature and is most likely mediated by key molecules, including calcitonin gene-related peptide (CGRP). This scoping review proposes that CGRP-mediated neuroinflammation in the trigeminal ganglion may partly explain the biomolecular bidirectional link between TMDs and chronic headaches. Finally, clinical implications of this neuropathologic process are briefly discussed.

Xerogenic medications may contribute to decreased unstimulated salivary flow in patients with oral burning and/or gastro-esophageal reflux disease

Background

Patients who complain of mucosal burning sensations (i.e., glossodynia and gastro-esophageal reflux disease, GERD) often take multiple medications. However, the relationship between xerogenic medication intake and salivary flow in these patients has not been thoroughly examined.

Methods

A retrospective study of 192 consecutive patients diagnosed with glossodynia (ICD-10-CM) at a regional center over a six-year period was performed. Data from electronic health records were extracted and relationships between medication intake, unstimulated whole salivary flow rate (UWSFR), xerostomia and GERD were determined by chi-square, t-test, and correlation analysis.

Results

Of 134 records that met inclusion criteria, 87.1% of patients reported daily intake of one or more xerogenic medications. Two or more xerogenic medications were taken significantly more often by patients with glossodynia reporting GERD than those with glossodynia without GERD (p = .02). UWSFR was negatively correlated with number of medications [r(103) = −.277, p = .005] and xerogenic medications [r(103) = −.195, p = .049]. The lowest UWSFR was observed with use of trazodone and cyclobenzaprine.

Conclusions

Daily xerogenic medication intake, hyposalivation, and xerostomia were commonly present and potentially interrelated in patients who suffer from glossodynia and/or GERD.

Practical implications

Clinicians should be aware of the consequences of prescribing multiple and certain xerogenic medications in reducing UWSFR, especially in patients physiologically at risk of hyposalivation such as those suffering from GERD and/or glossodynia.

The impact of sleep components, quality and patterns on glymphatic system functioning in healthy adults: A systematic review

OBJECTIVE

The glymphatic system is thought to be responsible for waste clearance in the brain. As it is primarily active during sleep, different components of sleep, subjective sleep quality, and sleep patterns may contribute to glymphatic functioning. This systematic review aimed at exploring the effect of sleep components, sleep quality, and sleep patterns on outcomes associated with the glymphatic system in healthy adults.

METHODS

PubMed®, Scopus, and Web of Science were searched for studies published in English until December 2021. Articles subjectively or objectively investigating sleep components (total sleep time, time in bed, sleep efficiency, sleep onset latency, wake-up after sleep onset, sleep stage, awakenings), sleep quality, or sleep pattern in healthy individuals, on outcomes associated with glymphatic system (levels of amyloid-β, tau, α-synuclein; cerebrospinal fluid, perivascular spaces; apolipoprotein E) were selected.

RESULTS

Out of 8359 records screened, 51 studies were included. Overall, contradictory findings were observed according to different sleep assessment method. The most frequently assessed sleep parameters were total sleep time, sleep quality, and sleep efficiency. No association was found between sleep efficiency and amyloid-β, and between slow-wave activity and tau. Most of the studies did not find any correlation between total sleep time and amyloid-β nor tau level. Opposing results correlated sleep quality with amyloid-β and tau.

CONCLUSIONS

This review highlighted inconsistent results across the studies; as such, the specific association between the glymphatic system and sleep parameters in healthy adults remains poorly understood. Due to the heterogeneity of sleep assessment methods and the self-reported data representing the majority of the observations, future studies with universal study design and sleep methodology in healthy individuals are advocated.

Clinical effects of different prescriptions on the inclination of maxillary and mandibular incisors by using passive self-ligating brackets

Objective

Controlling the incisal inclination is fundamental in orthodontics. However, the relationship between the inclination prescription and its clinical outcome is not obvious, and the incisal inclination changes generated by different bracket prescriptions were investigated.

Methods

Twenty-eight non-extraction dental Class II patients (15 females, 13 males; mean age = 12.9) were retrospectively analyzed. Patients were treated using passive self-ligating fixed appliances with three inclination prescriptions for maxillary incisors (high, standard, low), and two for mandibular incisors (standard, low). Clinical outcomes were compared among different prescriptions, and regression analysis was used to explain the effects of bracket prescriptions and to understand the prescription selection criteria (α = 0.05).

Results

For maxillary central incisors, low and high prescriptions were related to linguoversion (p = 0.046) and labioversion (p = 0.005), respectively, while standard prescription maintained the initial dental inclination. Maxillary lateral incisors did not show significant changes. For mandibular incisors, low prescription led to linguoversion (p = 0.005 for central incisors, p = 0.010 for lateral incisors), while standard prescription led to labioversion (p = 0.045 for central incisors, p = 0.005 for lateral incisors). The factors affecting inclination changes were the imposed change and selected prescription, while prescription selection was influenced by the initial dental inclination and initial intercanine distance.

Conclusions

The direction of correction of incisal inclination can be controlled by choosing a certain prescription, but the final inclination may show limited consistency with it. The amount of imposed inclination change was the most relevant predictor of the clinical outcome.

A Rare Case of Idiopathic Painful Nervus Intermedius Neuropathy in a 13-Year-Old Female: A Case Report and Discussion in the Context of the Literature

(1) Background: Painful nervus intermedius neuropathy involves continuous or near-continuous pain affecting the distribution of the intermedius nerve(s). The diagnosis of this entity is challenging, particularly when the clinical and demographic features do not resemble the typical presentation of this condition. To the best of our knowledge, only three case reports have described the occurrence of nervus intermedius neuropathy in young patients. (2) Case Description: A 13-year-old female referred to the orofacial pain clinic with a complaint of pain located deep in the right ear and mastoid area. The pain was described as constant, throbbing and dull, with an intensity of 7/10 on numerical rating scale, characterized by superimposed brief paroxysms of severe sharp pain. The past treatments included ineffective pharmacological and irreversible surgical approaches. After a comprehensive evaluation, a diagnosis of idiopathic painful nervus intermedius neuropathy was given, which was successfully managed with the use of gabapentin. (3) Conclusions and Practical Implications: The diagnosis and treatment of neuropathic pain affecting the nervus intermedius can be challenging due to the complex nature of the sensory innervation of the ear. The diagnosis can be even more challenging in cases of atypical clinical and demographic presentations, which in turn may result in unsuccessful, unnecessary, and irreversible treatments. Multidisciplinary teams and constant knowledge update are fundamental to provide good quality of care to our patients and not to overlook any relevant signs or symptoms.

Low Dose Naltrexone for Treatment of Burning Mouth Syndrome

OBJECTIVE

The International Classification of Disease defines burning mouth syndrome (BMS) as a chronic intraoral burning sensation, with no identifiable local or systemic cause. Since current management is often unsatisfactory, the aim of this report is to describe a new treatment modality (i.e., low-dose naltrexone [LDN]).

STUDY DESIGN

A 62-year-old woman presented with the complaint of burning on the tongue of 3 years' duration. Existing comorbidities were fibromyalgia, irritable bowel syndrome, headache, and interstitial cystitis. Her reported pain intensity ranged from 2/10 (morning) to 8/10 (evening) on a numeric rating scale. With the diagnosis of BMS and hyposalivation, and in light of her current clonazepam use and fibromyalgia, a dry mouth protocol and LDN (3 mg) were prescribed.

RESULTS

After 1 month, her pain intensity decreased by 50%, with no pain upon awakening. After 2 months, the widespread pain associated with her chronic morbidities also reduced by 50%, and her headache disappeared. After adjusting LDN dose to 4.5 mg, the patient was stable at 6 months, with 50% reduction of widespread pain and 2/10 BMS pain, and no reported side effects.

CONCLUSIONS

These preliminary results suggest that LDN may be a feasible and effective treatment for BMS, especially in patients' refractory to traditional treatment.

Remote digital monitoring during the retention phase of orthodontic treatment: A prospective feasibility study

Objective

To evaluate if a remote digital monitoring system added at the end of orthodontic treatment could positively influence the retention phase by reducing the occurrence of misfit of removable appliances, number of emergency appointments (EA), and orthodontic relapse.

Methods

Twenty-seven patients who completed active orthodontic treatment were divided into the study and control groups. In addition to the standard chairside follow-up appointments at month 1 (T1), month 3 (T2), month 6 (T3), the study group patients were monitored using Dental Monitoring^® with monthly intra-oral scans. Occurrence of misfit of removable retainers, number of EAs, and intercanine width change were recorded for both groups. Differences in EAs and retainer fit were assessed using the chi-square test. Intra-group and inter-group differences in the intercanine width were assessed with Friedman test and Mann–Whitney U test, respectively (α = 0.05).

Results

The study group showed a significantly lower occurrence of misfit of removable retainers (p = 0.027) compared to the control group. No significant inter- and intra-group difference was found in the EAs and intercanine width change at each time-point.

Conclusions

Integrating remote monitoring systems, such as Dental Monitoring^®, to the retention phase of the orthodontic treatment may lower the occurrence of misfit of removable retainers. However, a small sample size and a short observation period limit the strength of this evidence. These preliminary results tentatively suggest that remote monitoring technologies may be beneficial, especially during the COVID-19 pandemic, when the regularity of in-office visits might be disrupted.

Pediatric Chronic Orofacial Pain: A Narrative Review of Biopsychosocial Associations and Treatment Approaches

Pediatric chronic orofacial pain (OFP) is an umbrella term which refers to pain associated with the hard and soft tissues of the head, face, and neck lasting >3 months in patients younger than 18 years of age. Common chronic pediatric OFP diagnoses include temporomandibular disorder, headaches, and neuropathic pain. Chronic OFP can adversely affect youth's daily functioning and development in many areas of well-being, and may be associated with emotional stress, depression, functional avoidance, and poor sleep, among other negative outcomes. In this mini-review, we will discuss common psychological comorbidities and familial factors that often accompany chronic pediatric OFP conditions. We will also discuss traditional management approaches for pediatric orofacial pain including education, occlusal appliances, and psychological treatments such as relaxation, mindfulness-based interventions, and cognitive-behavioral treatments. Finally, we highlight avenues for future research, as a better understanding of chronic OFP comorbidities in childhood has the potential to prevent long-term pain-related disability in adulthood.

Proposed parameters of optimal central incisor positioning in orthodontic treatment planning: A systematic review

OBJECTIVE

Planning of incisal position is crucial for optimal orthodontic treatment outcomes due to its consequences on facial esthetics and occlusion. A systematic summary of the proposed parameters is presented.

METHODS

Studies on Google Scholar©, PubMed©, and Cochrane Library, providing quantitative information on optimal central incisor position were included.

RESULTS

Upper incisors supero-inferior position (4-5 mm to upper lip, 67-73 mm to axial plane through pupils), antero-posterior position (3-4 mm to Nasion-A, 3-6 mm to A-Pogonion, 9-12 mm to true vertical line, 5 mm to A-projection, 9-10 mm to coronal plane through pupils), bucco-lingual angulation (4-7° to occlusal plane perpendicular on models, 20-22° to Nasion-A, 57-58° to upper occlusal plane, 16-20° to coronal plane through pupils, 108-110° to anterior-posterior nasal spine), mesio-distal angulation (5° to occlusal plane perpendicular on models). Lower incisors supero-inferior position (41-48 mm to soft-tissue mandibular plane), antero-posterior position (3-4 mm to Nasion-B, 1-3 mm to A-Pogonion, 12-15 mm to true vertical line, 6-8 mm to coronal plane through pupils), bucco-lingual angulation (1-4° to occlusal plane perpendicular on models, 87-94° to mandibular plane, 68° to Frankfurt plane, 22-25° to Nasion-B, 105° to occlusal plane, 64° to lower occlusal plane, 21° to A-Pogonion), mesio-distal angulation (2° to occlusal plane perpendicular on models).

CONCLUSIONS

Although these findings can provide clinical guideline, they derive from heterogeneous studies in terms of subject characteristics and reference methods. Therefore, the optimal incisal position remains debatable.

Telehealth Increases Access to Brief Behavioral Interventions in Orofacial Pain Clinic during COVID-19 Pandemic: A Retrospective Study

Objective

Aim of the study was to test if orofacial pain patients were more likely to start and complete a brief psychological intervention for managing certain chronic orofacial pain conditions (physical self-regulation, PSR) via telehealth (during the COVID-19 pandemic) vs. in-person (prior to the COVID-19 pandemic). Exploratory aim was to describe demographic factors that may influence the patients to start and complete PSR.

Methods

Retrospective medical charts of all patients seen at a university-affiliated tertiary orofacial pain clinic between July–December 2019 (in person, pre-pandemic) and July–December 2020 (telehealth, during pandemic) were reviewed. Charts were examined for demographic information and to compare the number of patients who started and completed PSR during each study period (chi-squared test).

Results

Of 248 new patients seen in the clinic during 2019 period, 25 started PSR in-person (10.08%). Of 252 new patients seen during 2020 period, 53 started PSR via telehealth (21.03%). Patients were more likely to start PSR (OR = 6.21, p<.001, CI = 2.499 to 15.435) and more likely to complete all three sessions of PSR (OR = 5.69, p<.001, CI = 2.352 to 13.794) when it was offered via telehealth than in-person. Among those who started PSR via telehealth, patients from metropolitan areas were more likely to start the intervention than those from non-metropolitan areas (p=.045).

Conclusions

Offering brief psychological pain interventions via telehealth in tertiary orofacial pain clinics has demonstrated feasibility and may improve willingness to participate in psychological treatments. Results need to be replicated with prospective data as modality was confounded with pandemic in the current study.

Effects of remote digital monitoring on oral hygiene of orthodontic patients: a prospective study

Background

Remote digital monitoring during orthodontic treatment can help patients in improving their oral hygiene performance and reducing the number of appointments due to emergency reasons, especially in time of COVID-19 pandemic where non-urgent appointments might be discouraged.

Methods

Thirty patients scheduled to start an orthodontic treatment were divided into two groups of fifteen. Compared to controls, study group patients were provided with scan box and cheek retractor (Dental Monitoring®) and were instructed to take monthly intra-oral scans. Plaque Index (PI), Gingival Index (GI), and White Spot Lesions (WSL) were recorded for both groups at baseline (t₀), every month for the first 3 months (t₁, t₂, t₃), and at 6 months (t₄). Carious Lesions Onset (CLO) and Emergency Appointments (EA) were also recorded during the observation period. Inter-group differences were assessed with Student's t test and Chi-square test, intra-group differences were assessed with Cochran’s Q-test (significance α = 0.05).

Results

Study group patients showed a significant improvement in plaque control at t₃ (p = 0.010) and t₄ (p = 0.039), compared to control group. No significant difference was observed in the number of WSL between the two groups. No cavities were detected in the study group, while five CLO were diagnosed in the control group (p = 0.049). A decreased number of EA was observed in the study group, but the difference was not significant.

Conclusions

Integration of a remote monitoring system during orthodontic treatment was effective in improving plaque control and reducing carious lesions onset. The present findings encourage orthodontists to consider this technology to help maintaining optimal oral health of patients, especially in times of health emergency crisis.

Attitude towards Telemonitoring in Orthodontists and Orthodontic Patients

The purpose of this study was to analyze the attitude of dentists and patients towards the use of Dental Monitoring^TM (DM), an orthodontic telemonitoring software. Thus, two different specially prepared specific questionnaires were administered to 80 dentists (40 were general dentists and 40 orthodontists) and 80 orthodontic patients. All dentists judged positively telemonitoring, as 96.25% of them considered telemonitoring indicative of high tech and high-quality treatment; 100% considered it a way to reduce the number of in-office visits; 17.5% agreed on a weekly telemonitoring frequency, 40% on a biweekly, and 42.5% on a lower frequency. Further, 97.5% of patients judged positively telemonitoring; 81.25% of them considered telemonitoring indicative of high-tech treatment; 81.25% declared to be interested in reducing the number of in-office visits through telemonitoring; 27.5% agreed on taking self-picture every week, 57.5% every two weeks, and 15% on a lower frequency. Both patients and dentists positively judged telemonitoring, considering it a technologically advanced tool increasing the perception of quality and accuracy of the treatment. Both groups were interested in reducing the number of in-office visits, although not all of them revealed to be ready to invest more money and time in it.

Distal Arteriovenous Fistulas in Elderly Hemodialysis Patients

Dialysis access procedures and complications are an important cause of morbidity and hospitalization for chronic hemodialysis patients. Subjects over 65 years old have a higher incidence of co-morbid factors (diabetes mellitus, atherosclerosis, neoplasms, heart failure), therefore the correct choice in terms of timing and type of permanent access is extremely important. As elbow fistulas are often complicated by heart failure and PTFE grafts have a higher risk of thrombosis, we decided to evaluate the success rate of distal fistula as primary dialysis access in elderly patients. We carried out a retrospective study to identify survival predictors and actual vascular network saving.

Between January 1991 and September 2000, 277 vascular access procedures were performed on 198 elderly patients (age 65 or older). The first anastomosis was positioned as peripherally as possible. In cases of patients with poor peripheral vasculature or three co-morbid factors, vascular access was first created at the origin of radial artery (Toledo-Pereyra fistula). Survival (Kaplan – Meyer analysis) was significantly higher for Toledo-Pereyra fistulas compared to wrist and snuff-box ones, in spite of the presence of a high incidence of co-morbid factors. We conclude that Toledo-Pereyra fistula is an efficient primary choice in elderly patients.

Evaluation of the protective effects of alpha-tocopherol and retinol against ochratoxin A cytotoxicity

Ochratoxin A (OTA), a mycotoxin frequently present in food and feedstuffs, produces a wide range of toxic effects, including cell death via lipid peroxidation. In one human and four animal cell lines we determined the half lethal concentration (LC50) of OTA, its effect on reactive oxygen species (ROS) production, and its ability to induce cytochrome p450 activity. We also examined the protective effect of alpha-tocopherol and all-trans-retinol in the most sensitive cell lines (i.e. bovine mammary epithelia, for which LC50 was 0.8 microg/ml (24 h), and Madin Darby canine kidney, for which LC50 was 4.3 microg/ml (48 h)). Pre-incubation for 3 h with either antioxidant significantly (P<0.05) ameliorated the OTA-induced reduction in cell viability and significantly decreased (P<0.05) ROS production. These findings indicate that oxidative stress is an important factor in OTA cytotoxicity. Supplementation with antioxidant molecules may counteract the short-term toxicity of this mycotoxin.

105VITRIFICATION OF BOVINE EMBRYOS USING THE CLV METHOD

Vitrification has become the preferred method for cryopreserving in vitro-produced bovine embryos (IVP). Here we introduce a technique for vitrification developed at CryoLogic (the CLV Method), in conjunction with a study comparing the post-thaw viability of IVP embryos frozen by the widely used open pulled straw method (OPS—Vajta et al., 1997 Cryo-Letters 18, 191) and the new CLV Method. Vitrification on thin metal surfaces has been explored and demonstrated previously (Le Gal &amp; Massip 1999, Cryobiology 38, 290), and Dinnyes presented a Solid Surface Vitrification (SSV) (Dinnyes et al., 2000, Biol. Reprod. 63, 513). The CLV Method utilizes vitrification on the surface of a solid metal block. This surface has been custom shaped and treated to enhance vitreous formation. The method also includes handling, storage and thawing protocols designed to avoid damage from crystallization of the unstable glass. Briefly, the block is precooled in LN2 to −196°C. Up to 10 embryos are collected into a droplet of medium (3μL), on the end of a fibre carrier attached to a handle. The droplet is presented to the vitrification surface, where it is converted into a glass bead by cooling rates comparable to that of plunging into solid/liquid phase nitrogen (−210°C) (Arav et al., 2001 Theriogenology 55, 313). The glass bead, fibre and handle are transferred quickly into a half-sealed, precooled straw, and the handle seals the open end. A bead is thawed very rapidly by removing the handle, fibre and bead from the straw and transferring the bead into washing medium. COCs collected from bovine ovaries obtained from abattoirs were matured, fertilized and cultured for 6 days (Fry et al., 2003 Theriogenology 59, 446). Embryos reaching the blastocyst or expanding blastocyst stage of development were graded (Grades 1, 2, and 3), equilibrated for 5min in HEPES-199 medium with 20% FCS (HFm), placed in HFm with 10% EG, and 10% DMSO (VS1) for 2min, and then transferred to HFm with 20% EG, 20% DMSO (VS2) for 30s (Vajta). Between 5 and 10 IVP embryos were processed and collected for vitrification, either in an OPS plunged into LN2, or in a 3μL droplet vitrified by the CLV Method. The two sets of specimens were stored in LN2, and later thawed. Both OPS tips and beads were thawed in 0.5mL of HFm with 0.2M sucrose at 39°C. Embryos were maintained at 39°C, examined after 5min for contraction, and again after 6 h for re-expansion. They were then transferred to culture medium, incubated and examined at 24 and 48h to assess hatching. As shown in Table 1, the CLV method appears to be satisfactory for maintaining membrane integrity (expansion) and developmental potential (hatching) for even poorer grade embryos, that might be more sensitive to the stresses of cryopreservation. Table 1 Re-expansion and hatching rates of graded thawed bovine embryos vitrified by OPS or CLV methods

Rumen-protected choline administration to transition cows: effects on milk production and vitamin E status

We investigated the influence of rumen-protected choline (RPC) supplementation on milk production, lipid metabolism and vitamin E status in dairy cows receiving a silage-based diet. Twenty-six Italian Holstein multiparous cows were assigned by weight and average production in the previous lactation, to one of two groups: control (no RPC supplementation) and RPC (supplemented with 20 g/day rumen-protected choline chloride). Treatment began 14 days before expected calving and continued for 30 days after parturition. Choline administration significantly increased milk production during the first month of lactation and also the concentration (and total secretion) of choline in milk, but did not affect fat or protein concentrations in milk, or plasma levels of glucose, beta-hydroxybutyrate, cholesterol and non-esterified fatty acids (NEFA). However, around parturition, NEFA concentrations in plasma were lower in treated animals than in controls, suggesting improved lipid metabolism as a result of choline supplementation. Choline supplementation also increased alpha-tocopherol plasma concentrations, suggesting a novel aspect in dairy cows.

Hemoperitoneum in a continuous ambulatory peritoneal dialysis patient caused by a hepatocarcinoma treated with percutaneous embolization

Hemoperitoneum is an infrequent but normally benign complication in continuous ambulatory peritoneal dialysis (CAPD) patients. It can occur at any time during peritoneal dialytic treatment. Hemoperitoneum is not associated with a specific disease and usually disappears spontaneously. In 20% of cases, however, hemoperitoneum is severe and requires specific investigation and emergency therapy. We report a case of hemoperitoneum in a 70-year-old, anti-hepatitic C virus-positive woman. After 48 months of CAPD treatment, a bloody peritoneal effluent developed, with severe anemia (hematocrit decreased from 30% to 20%). An abdominal computed tomography scan showed three hepatic lesions with signs of hepatic neoplasms; selective hepatic arteriography confirmed the diagnosis. Chemoembolization of the three lesions was performed, and hemoperitoneum disappeared within a few hours.

Direct effect of the correction of acidosis on plasma parathyroid hormone concentrations, calcium and phosphate in hemodialysis patients: a prospective study

BACKGROUND

Metabolic acidosis contributes to renal osteodystrophy and together with hyperphosphatemia, hypocalcemia and altered vitamin D metabolism may result in increased levels of intact parathyroid hormone (iPTH) and metastatic calcifications. However, the impact of the correction of metabolic acidosis on iPTH levels and calcium-phosphate metabolism is still controversial.

STUDY DESIGN

The effects of the correction of metabolic acidosis on serum concentrations of iPTH, calcium (Ca), phosphate (PO(4)) and alkaline phosphatase were prospectively studied. Twelve uremic patients on maintenance hemodialysis (HD) for 49 months (median; range 6-243 months) with serum bicarbonate levels < or =20 mmol/l were studied before and after 3 months of oral sodium bicarbonate supplementation. Predialysis serum bicarbonate, arterial pH, ionized calcium, plasma sodium, plasma potassium, serum creatinine, hemoglobin, K(t)/V, postdialysis body weight, predialysis systolic and diastolic blood pressure were also evaluated before and after correction.

RESULTS

Serum bicarbonate levels and arterial pH increased respectively from 19.3 +/- 0.6 to 24.4 +/- 1.2 mmol/l (p < 0.0001) and 7.34 +/- 0.03 to 7.40 +/- 0.02 (p < 0.001). iPTH levels decreased significantly from 399 +/- 475 to 305 +/- 353 pg/ml (p = 0.026). No changes in total serum Ca, plasma PO(4), serum akaline phosphatase, K(t)/V, serum creatinine, hemoglobin, body weight, predialysis systolic and diastolic blood pressures were observed. iCa decreased significantly.

CONCLUSIONS

Our study demonstrates that the correction of metabolic acidosis in chronic HD patients reduces iPTH concentrations in HD patients with secondary hyperparathyroidism possibly by a direct effect on iPTH secretion.

Correction of metabolic acidosis increases serum albumin concentrations and decreases kinetically evaluated protein intake in haemodialysis patients: a prospective study

BACKGROUND

Metabolic acidosis in haemodialysis (HD) patients increases whole body protein degradation while the correction of acidosis reduces it. However, the effects of the correction of acidosis on nutrition have not been clearly demonstrated.

STUDY DESIGN

In this study we have evaluated the effects of 3 months of correction of metabolic acidosis by oral sodium bicarbonate supplementation on protein catabolic rate (PCRn) and serum albumin concentrations in 12 uraemic patients on maintenance HD for at least 6 months (median 49 months; range 6-243 months). Pre-dialysis serum bicarbonate, arterial pH, serum albumin, total serum proteins, serum creatinine, plasma sodium, haemoglobin, PCRn, Kt/V, and TACurea, were evaluated before and after correction.

RESULTS

Serum bicarbonate levels and arterial pH increased respectively from 19.3 +/- 0.6 mmol/l to 24.4 +/- 1.2 mmol/l (P < 0.0001) and 7.34 +/- 0.03 to 7.40 +/- 0.02 (P < 0.0001). Serum albumin increased from 34.9 +/- 2.1 g/l to 37.9 +/- 2.9 g/l (P < 0.01), while PCRn decreased from 1.11 +/- 0.17 g/kg/day to 1.03 +/- 0.17 g/kg/day (P < 0.001). No changes in Kt/V, total serum proteins, serum creatinine, plasma sodium, haemoglobin, body weight, pre dialysis systolic and diastolic blood pressure, and intradialytic weight loss were observed.

CONCLUSIONS

Our data demonstrate that correction of metabolic acidosis improves serum albumin concentrations in HD patients. The correction of acidosis induces a decrease in PCRn values, as evaluated by kinetic criteria, suggesting that in the presence of moderate to severe acidosis this parameter does not reflect the real dietary protein intake of the patients probably as a result of increased catabolism of endogenous proteins. The correction of metabolic acidosis should be considered of paramount importance in HD patients.

Feasibility of a long-term low-sodium diet in mild hypertension

The present study set out to assess the feasibility of long-term moderate dietary sodium restriction in patients with mild hypertension in general practice. After screening and a run-in phase of 6-8 weeks, a total of 77 previously undiagnosed mildly hypertensive patients were identified. Half of them were randomized to receive a few simple dietary instructions from their general practitioners in order to reduce salt usage; the others were randomized to receive no advice. The patients were followed up for 12 months with quarterly visits. A total of 56 patients (72.7%) completed the study, 26 on a low-sodium diet (LD) and 30 on their usual diet (UD). At each visit in the diet phase, patients provided 24h urine, which was analysed for volume and sodium concentration in order to assess their sodium intake. Blood pressure, heart the rate and body weight were recorded. The mean urinary sodium excretion for all diet phase visits overlapped in the two groups (177.0 +/- 32.9 vs. 169.3 +/- 49.4 mEq/24h respectively in the LD and UD groups). Nevertheless the mean systolic and diastolic blood pressures for all diet phase visits were significantly lower in the LD than in UD group (144.2 +/- 11.1/91.6 +/- 6.4 and 148.0 +/- 13.7/95.6 +/- 4.7 mmHg respectively, P less than 0.01). Our data suggest that it is not feasible at present to reduce sodium intake in mild hypertensives with simple and inexpensive dietary instructions, the only ones suitable for widespread application in general practice.

Placental transfer, tissue distribution, and pharmacokinetics of cyclosporine in the pregnant rabbit

The disposition of cyclosporine during pregnancy is described for the first time using the pregnant rabbit model. After a detailed kinetic study, in which a 5 mg/kg dose of cyclosporine was used, the apparent tissue-to-blood partition coefficients were determined at steady state in six pregnant rabbits after a two-step infusion of cyclosporine for 8 hr at a mean arterial blood concentration of 1.25 mg/liter, detected by HPLC. Muscle and fat were major drug deposits, and the maternal kidney--site of considerable side effects--accumulated the highest concentration of the drug. Spleen, mammary gland, liver, lung, heart, bile, and adrenal gland showed intermediate ability to accumulate the drug. The whole fetus accumulated little cyclosporine, and the drug was not detectable in maternal and fetal brains and in the amniotic fluid. At delivery, the mean cyclosporine concentration in fetal blood was 0.07 mg/liter, amounting to 6% of the mother's concentration. It would appear that diffusional resistance governs the transfer of cyclosporine into brain and fetus. Although caution obviously must be applied in extrapolating experimental data to clinical situations, the present findings do suggest that: a) exposure of the fetus to cyclosporine is low at a high maternal steady-state concentration; and b) caution should be applied in suggesting breastfeeding by these patients, since cyclosporine was found in a considerable amount in the mammary gland.

Cyclosporine pharmacokinetics in rats and interspecies comparison in dogs, rabbits, rats, and humans

The pharmacokinetics of cyclosporine, a potent immunosuppressive agent, are described for rats given 5 mg/kg iv, measuring blood concentrations by a specific HPLC method. Cyclosporine followed first-order kinetics and blood concentrations vs. time data were adequately described by a three-compartment open model system. The mean half-life of the lambda 1 phase was 0.11 hr, that of the lambda 2 phase was 1.82 hr, and the half-life of the estimated lambda 3 phase was 23.79 hr. The mean apparent volume of distribution and Vss were 5.69 and 4.54 liters/kg, respectively. The mean blood total body clearance was 3.38 ml/min/kg. The literature was reviewed to obtain comparable data from other mammalian species, and satisfactory kinetic information was found for humans, dogs, and rabbits. Interspecies variants in physiological parameters and cyclosporine pharmacokinetics were considered and treated as a property and consequence of body size (allometry), nullifying anatomical and physiological differences between species. A relationship between pharmacokinetic time (a variable in terms of chronological time) and body weight was found. It is suggested that the metabolic capacity (based on liver weight) to eliminate cyclosporine is similar in humans, rabbits, and rats, whereas the dog showed a potentially double capacity to metabolize the drug. However, metabolic and pharmacodynamic studies are also needed to predict toxicity accurately among species.

ATP as a marker of excitotoxin-induced nerve cell death in vivo

In an attempt to find an marker for nerve cell death in vivo, the ATP content was measured in the rat dorsal hippocampus within hours or days following in the local injection of the excitotoxins quinolinic or kainic acid. Beginning or completed neuronal degeneration is accompanied by significant decreases in ATP levels. Selective blockade of the quinolinic acid-induced decrement in ATP content by D-(-) 2-amino-7-phosphonoheptanoic acid indicates that ATP measurements may of value for the rapid in vivo screening of the anti-neurotoxic properties of pharmacologically distinct excitatory amino acid receptor antagonists.

Reversed-phase high-performance liquid chromatography determination of cyclosporin in human blood

A high-performance liquid chromatographic (HPLC) method for determination of cyclosporin A (CyA) in blood, using cyclosporin D (CyD) as internal standard, is described. The method is specific, precise, reproducible, accurate, and isocratic, and it requires no derivatization. It is more rapid than previously described methods. Its detection limit is 25 ng/ml, suitable for quantitation of the drug at clinically observed concentrations. No interference was found by any of the other commonly coadministered drugs tested. Comparison of measurements in patients' blood with radioimmunoassay (RIA) results showed lower estimates by the chromatographic technique. Because measurements of the drug in blood banks spiked with pure CyA were similar with the two techniques, the nonspecificity of RIA, probably related to cyclosporin metabolites, was demonstrated. Because the chromatographic technique is simple, it should be preferred to RIA in therapeutic drug monitoring.