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).     

Prevalence of total tooth loss, dental caries, and periodontal disease in Mexican-American adults: results from the southwestern HHANES

The Southwestern portion of the Hispanic Health and Nutrition Examination Survey (HHANES) was conducted by the National Center for Health Statistics (NCHS) in 1982 and 1983. The survey population was Mexican-Americans residing in five Southwestern states. This report presents data on the prevalence of total tooth loss, dental caries, and periodontal diseases in 3860 Mexican-American adults aged from 18 to 74. Results show that 4.3% of this group was edentulous. Among the dentate, Mexican-Americans had lower overall DMF scores but higher numbers of untreated decayed teeth than did residents of the same region seen in the NHANES I survey in 1971-1974. Caries of the smooth surfaces in both posterior and anterior teeth was more pronounced in the older than in the younger age groups. Mexican-Americans had more gingivitis but fewer periodontal pockets than did the general population in the Western states during NHANES I. The caries pattern in the Mexican-Americans suggests that caries among adults may remain a problem in the future, with the possibility of increased involvement with the aging, although modest, of smooth tooth surfaces.     

Magnetic Resonance Cisternography in the Diagnosis of Delayed Iatrogenic Cerebrospinal Fistula: A Case Report

A 52–year–old woman presented with a clinical picture consistent with bacterial meningitis 3 years after functional endoscopic sinus surgery. Diagnosis of a cerebrospinal fluid (CSF) fistula was made clinically, and the site of the fistula was confirmed using magnetic resonance cisternography. The utilization of this technique in the diagnosis of CSF disorders is gaining popularity. Its usefulness in the context of other imaging modalities is discussed.     

Implementation of Comprehensive School Health Education in Elementary Schools: Focus on Teacher Concerns

ABSTRACT: This paper reports on the effectiveness of a teacher development project in promoting implementation of a comprehensive school health education curriculum among inner city elementary school teachers. The longitudinal evaluation design provides empirical data on the efficacy of a strategy to reduce teachers' concerns and promote use of the curriculum at the classroom level. Data were collected at various points throughout the project period from 156 school staff from five schools. Results from analyses of repeated measures of teachers' feelings of preparedness to teach specific health topics, and the observed relationship between both high and improved feelings of preparation and reported health teaching suggest that teacher development efforts including training and ongoing reinforcement to increase teachers' feelings of preparedness can have significant classroom effects.     

Comparison of purified indium-111 granulocytes and indium-111 mixed leukocytes for imaging of infections

Several methods have been proposed for the separation and labeling of white blood cells for the diagnosis of suspected infection. We retrospectively compared 105 patients imaged with 111In purified granulocytes (GRAN) to 106 patients imaged with 111In mixed leukocytes (MIX). We found that in acute infection the sensitivity of GRAN and MIX were both high and not statistically different. In chronic infections the sensitivities were lower than for acute infections. Again, there was no significant difference between GRAN and MIX with the borderline significant exception of MIX being superior to GRAN in chronic soft tissue infections (p = 0.06). We then had independent observers blindly grade the degree of lesion visualization. We found that delayed images visualized the lesions better than early images (p = 0.0001) and acute infection was better visualized than chronic infection (p = 0.03). We concluded that, in routine clinical practice, MIX is probably the agent of choice for three reasons: (a) easier preparation, (b) comparable sensitivity in acute infection and, (c) borderline superior sensitivity in chronic infection.     

A model of reversible obstructive jaundice in the rat

A model of reversible, extrahepatic biliary obstruction is described. Vessel loop blockade of the biliary tree results in obstructive jaundice while removal of the exteriorized vessel loop provides internal biliary drainage without subsequent laparotomy. This technique combined with a system for chronic venous infusion and arterial blood sampling in the unrestrained rat is ideal for long-term metabolic studies of obstructive jaundice. Male Fisher 344 rats (275-350 g) underwent either the combined procedure of total biliary tract blockade and vascular access or sham operation. Mean serum bilirubin was significantly elevated (12.7 +/- 8.9 mg/dl) in the experimental group and following relief of biliary obstruction significantly dropped below 1 mg/dl in all animals except one. Concomitant changes in alkaline phosphatase, glutamate oxaloacetate transaminase, and glutamate pyruvate transaminase were seen. Experimental and control rats initially lost weight following laparotomy; however, mean body weight stabilized by the 5th postoperative day and was similar in both groups on the 10th postoperative day. This combined procedure is a simple, effective and reproducible method of obstructive jaundice.     

Serodiagnosis of Crimean-Congo haemorrhagic fever.

Several methods for demonstrating antibody to Crimean-Congo haemorrhagic fever virus were compared on serum samples taken from 101 patients during the acute stage of illness and at intervals for up to 59 months thereafter, with emphasis on early detection of the immune response. The deaths of 23 patients on days 5-14 of illness were ascribed to the effects of the disease; two patients died later from other causes. Very few of the patients who died from the acute illness mounted an antibody response detectable by the methods tested. Four patients who died and 18 who recovered were treated with immune plasma collected from recovered patients. Treated patients acquired IgG antibody from the plasma, but it was possible to discern the onset of an endogenous IgM response in those individuals who survived the disease by all of the methods tested. Indirect immunofluorescence (IF) tests detected IgM and/or IgG antibodies at the earliest on day 4 of illness in about 10% of patients who survived the disease, and by day 9 all survivors had antibodies demonstrable by IF. A biotin-streptavidin IF technique offered no advantage over the standard IF test for the early detection of IgG antibody, but demonstrated higher antibody titres and detected IgM antibody earlier in about a quarter of the patients tested. An IgM-capture enzyme-linked immunoassay (ELISA) and an IgG sandwich ELISA demonstrated higher antibody titres than did IF tests, and detected antibody responses at an earlier stage of infection than did IF tests in about one-fifth of patients, but the reverse was true in a similar proportion of instances. A competition ELISA, which detected total antibody activity, produced lower titres than did the IgM and IgG ELISAs, but yielded results which were in close agreement with the findings in IF tests. It was concluded that the IF tests were most convenient for use in making a rapid serodiagnosis of the disease.     

Differential expression of two forms of GABAA receptor gamma 2-subunit in mice.

The gamma-aminobutyric acid type A (GABAA) receptor gamma 2-subunit is important for benzodiazepine action. In previous studies, two forms of gamma 2-subunit have been found which are generated by RNA alternative splicing (gamma 2L and gamma 2S) and differ by the presence or absence of an 8-amino acid insertion in the major intracellular loop between proposed transmembrane domains M3 and M4. We have used the RNase protection assay to study regulation of expression of the two forms of gamma 2-subunit in mouse brain, as judged from mRNA levels. We find that gamma 2L and gamma 2S are differentially expressed in brain regions and that gamma 2S is expressed at a fairly constant level during brain development while gamma 2L increases dramatically with maturation. Their differentially regulated expression suggests further that gamma 2L and gamma 2S form receptors with important functional differences.     

Increased circulating interleukin-7 levels in HIV-1-infected women

Sex-based differences in CD4 T-cell (CD4) counts are well recognized, but the basis for these differences has not been identified. Conceivably, homeostatic factors may play a role in this process by regulating T-cell maintenance and repletion. Interleukin (IL)-7 is essential for normal T-cell production and homeostasis. We hypothesized that differences in IL-7 might contribute to sex-based differences in CD4 counts. Circulating IL-7 levels were analyzed in 299 HIV-1-infected women and men. Regression analysis estimated that IL-7 levels were 40% higher in women than in men (P = 0.0032) after controlling for CD4 count, age, and race. Given the important role of IL-7 in T-cell development and homeostasis, these findings suggest that higher IL-7 levels may contribute to higher CD4 counts in women.