Methamphetamine abuse and “meth mouth” in Europe

With easy chemical synthesis from its precursor, methamphetamine (MA) is now widespread in many countries. The abuse of methamphetamine is associated with several negative effects on health, because MA is a neurotoxin and a dangerous central nervous system stimulant. It changes levels of neurotransmitters in the brain, releasing dopamine and inhibiting nor epinephrine uptake which increases sympathetic nervous system activity and can lead to cardiac arrhythmia, hypertension and tachypnea. The consequences of MA abuse are clearly manifested in oral diseases (like “meth mouth”) which is characterised by extensive caries, teeth grinding with ensuing dental wear and trismus. The present review was designed to fill the gap in knowledge about methamphetamine abuse in the European Union (EU) and to illustrate the main clinical effects of prolonged use. After describing the pharmacology and systemic effects of methamphetamine and concentrating on its effects on the mouth, the present review compares the epidemiology and incidence of abuse in the world, particularly the USA and the EU. Key words:Methamphetamine, “Meth mouth”, drug abuse, oral health.     

Bone Microarchitecture Phenotypes Identified in Older Adults Are Associated With Different Levels of Osteoporotic Fracture Risk

Prevalence of osteoporosis is more than 50% in older adults, yet current clinical methods for diagnosis that rely on areal bone mineral density (aBMD) fail to detect most individuals who have a fragility fracture. Bone fragility can manifest in different forms, and a “one-size-fits-all” approach to diagnosis and management of osteoporosis may not be suitable. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides additive information by capturing information about volumetric density and microarchitecture, but interpretation is challenging because of the complex interactions between the numerous properties measured. In this study, we propose that there are common combinations of bone properties, referred to as phenotypes, that are predisposed to different levels of fracture risk. Using HR-pQCT data from a multinational cohort (n = 5873, 71% female) between 40 and 96 years of age, we employed fuzzy c-means clustering, an unsupervised machine-learning method, to identify phenotypes of bone microarchitecture. Three clusters were identified, and using partial correlation analysis of HR-pQCT parameters, we characterized the clusters as low density, low volume, and healthy bone phenotypes. Most males were associated with the healthy bone phenotype, whereas females were more often associated with the low volume or low density bone phenotypes. Each phenotype had a significantly different cumulative hazard of major osteoporotic fracture (MOF) and of any incident osteoporotic fracture (p < 0.05). After adjustment for covariates (cohort, sex, and age), the low density followed by the low volume phenotype had the highest association with MOF (hazard ratio = 2.96 and 2.35, respectively), and significant associations were maintained when additionally adjusted for femoral neck aBMD (hazard ratio = 1.69 and 1.90, respectively). Further, within each phenotype, different imaging biomarkers of fracture were identified. These findings suggest that osteoporotic fracture risk is associated with bone phenotypes that capture key features of bone deterioration that are not distinguishable by aBMD. © 2021 American Society for Bone and Mineral Research (ASBMR).     

Introducing dental students to clinical patient care: The complete denture prosthodontics transition clinic

Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience.     

Regional patterns of bone loss and altered bone remodeling in response to calcium deprivation in laboratory rabbits

Summary This study explores the effects of a calcium-deficient diet on patterns of bone remodeling, and examines regional differences in the amount of bone lost. Skeletally mature female rabbits (n=6) were fed a calcium-deficient diet (0.10% Ca²⁺ and 0.50% P) for 14 weeks. A separate group of rabbits (n=4) were fed a maintenance diet (1.2% Ca²⁺ and 0.45% P). Bone mineral content, serum calcium, and serum phosphorus were measured each week during the experimental period. Following sacrifice, the L₃ vetebra, femoral head, proximal tibial metaphysis, and tibial midshaft were analyzed histomorphometrically. Rabbits had 20% less vertebral bone after only 14 weeks of a calcium-deficient diet. As in human postmenopausal osteoporosis, bone loss in calcium-deficient rabbits occurs in the trabecular bone of the lumbar spine before that in the trabecular bone of the lower extremity. Calcium-deficient diets alone do not lead to increased osteoid volume or thickness. Because bone loss is relatively rapid and because the pattern of loss is similar in some respects to that found in humans, adult rabbits may provide an attractive model of calcium deficiency osteoporosis in a skeletally mature mammal in which remodeling is predominant over modeling.     

Risk factors for rhabdomyolysis with simvastatin and atorvastatin.

OBJECTIVE: To assess the frequency of risk factors for rhabdomyolysis with simvastatin and atorvastatin in cases reported to the Australian Adverse Drug Reactions Advisory Committee (ADRAC). DESIGN: Reports meeting the definition of rhabdomyolysis were reviewed for risk factors including age > or = 70 years, dose > or = 40 mg, hepatic dysfunction, diabetes mellitus, hyperkalaemia, hypothyroidism and the use of concomitant interacting medications. RESULTS: Only one report associated with simvastatin and five reports associated with atorvastatin did not list any risk factors for rhabdomyolysis. Interacting medicines featured in 77% of reports of rhabdomyolysis associated with simvastatin and 44% of reports associated with atorvastatin. A comparison of the age profile for reports of atorvastatin- and simvastatin-associated rhabdomyolysis with that for all adverse drug reaction reports received, and for all reports of muscle disorders, suggested a trend towards an increasing risk of rhabdomyolysis with increasing age with simvastatin but not with atorvastatin. Similarly, comparing prescribed tablet strengths from Pharmaceutical Benefits Scheme data with the HMG-CoA reductase inhibitor ('statin') doses in reports of rhabdomyolysis suggested a dose-related risk with simvastatin, but a less increased risk with high-dose atorvastatin. CONCLUSION: Risk factors for rhabdomyolysis featured in nearly all of the reports of statin-associated rhabdomyolysis and the majority of reports listed multiple risk factors, although dependence on risk factors appeared to be stronger with simvastatin than atorvastatin. The multiplication of risk factors in patients taking simvastatin and atorvastatin should be minimised.     

Importance of the duration of inhibition on intestinal carcinogenesis by difluoromethylornithine in rats

The effect of the duration and sequence of inhibition of intestinal tumor formation in rats was studied to determine whether part time inhibition has any value. Four groups of male Sprague-Dawley rats were given 8 weekly s.c. injections of azoxymethane (AOM) 8 mg/rat. Three groups were given the inhibitor, difluoromethylornithine (DFMO) in the drinking water; one for the entire 26 weeks of the study, one for the first 13 weeks only, and one for the last 13 weeks. A control group was not given the inhibitor. While the continuous treatment group developed the least number of tumors per rat (1.5 vs. 5 for controls), still both groups given the inhibitor for just 13 weeks also developed fewer tumors than controls 5 vs. 3.2 (early treatment) and 5 vs. 2.8 (late treatment). These results show that part time inhibition, including its late application, does reduce intestinal tumor formation in rats.