The HIF-1α/PLOD2 axis integrates extracellular matrix organization and cell metabolism leading to aberrant musculoskeletal repair

While hypoxic signaling has been shown to play a role in many cellular processes, its role in metabolism-linked extracellular matrix (ECM) organization and downstream processes of cell fate after musculoskeletal injury remains to be determined. Heterotopic ossification (HO) is a debilitating condition where abnormal bone formation occurs within extra-skeletal tissues. Hypoxia and hypoxia-inducible factor 1α (HIF-1α) activation have been shown to promote HO. However, the underlying molecular mechanisms by which the HIF-1α pathway in mesenchymal progenitor cells (MPCs) contributes to pathologic bone formation remain to be elucidated. Here, we used a proven mouse injury-induced HO model to investigate the role of HIF-1α on aberrant cell fate. Using single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics analyses of the HO site, we found that collagen ECM organization is the most highly up-regulated biological process in MPCs. Zeugopod mesenchymal cell-specific deletion of Hif1α (Hoxa11-CreERT2; Hif1afl/fl) significantly mitigated HO in vivo. ScRNA-seq analysis of these Hoxa11-CreERT2; Hif1afl/fl mice identified the PLOD2/LOX pathway for collagen cross-linking as downstream of the HIF-1α regulation of HO. Importantly, our scRNA-seq data and mechanistic studies further uncovered that glucose metabolism in MPCs is most highly impacted by HIF-1α deletion. From a translational aspect, a pan-LOX inhibitor significantly decreased HO. A newly screened compound revealed that the inhibition of PLOD2 activity in MPCs significantly decreased osteogenic differentiation and glycolytic metabolism. This suggests that the HIF-1α/PLOD2/LOX axis linked to metabolism regulates HO-forming MPC fate. These results suggest that the HIF-1α/PLOD2/LOX pathway represents a promising strategy to mitigate HO formation.

An evaluation of metabolic risks for coronary death in the Asia Pacific region

AIM

To investigate the generalizability of current definitions of the metabolic syndrome in Asia-Pacific populations, and whether information on metabolic risk factors could be better used to discriminate fatal coronary heart disease (CHD) risk.

METHODS AND RESULTS

Analyses were performed on individual participant data from 26 cohorts involving 329, 166 participants from the Asia Pacific region. Sensitivity and specificity estimates for CHD death associated with cut-points as defined by the U.S. National Cholesterol Education Panel (NCEP) were determined for component risk factors of a modified NCEP-defined metabolic syndrome. Five cohorts (6437 subjects, 53 CHD deaths) measuring all five risk factors at baseline were used to evaluate the association between the metabolic syndrome and CHD, and to compare risk discrimination using a definition including each risk factor as a continuous variable. Sensitivity and specificity estimates for risk factor cut-points varied considerably by region (Asia versus Australia/New Zealand) and moderately by sex. The adjusted hazard ratio for CHD death associated with the modified NCEP-defined metabolic syndrome was 2.05 (95%CI, 1.13-3.72). On receiver operator characteristic analysis, the area-under-the-curve for CHD death was 0.586 (95%CI: 0.439-0.732) for the modified NCEP-defined metabolic syndrome, and 0.733, 95%CI: 0.664-0.802) for a definition including each of the metabolic risk factors in their continuous form.

CONCLUSION

Specific cut-points for metabolic risk factors are not generalizable between populations. This finding is not restricted to measures of central obesity. A multivariable definition of the metabolic syndrome including all risk factors as continuous variables improves CHD risk discrimination substantially.

Physical therapy assessment and treatment protocol for nursing home residents

This article describes a standard protocol for assessing physical function in elderly nursing home residents. Major physical dimensions that are measured with the protocol include range of motion, muscle force, muscle reflex activity, sensation, soft tissue status, balance/coordination, and posture. A practical, functionally prioritized treatment model based on the assessment is also presented. The standardized assessment and treatment plan may be useful to the physical therapist in (1) planning and prioritizing treatment, (2) identifying when goals have been met, (3) recognizing when there is a need for treatment plan modification, and (4) educating physical therapy students in applying problem-solving skills in their treatment sessions.

Prospective evaluation of gastric emptying in the self-poisoned patient

The authors prospectively studied the effect of gastric emptying (GE) and activated charcoal (AC) upon clinical outcome in acutely self-poisoned patients. Presumed overdose patients (n = 808) were treated using an alternate day protocol based on a 10-question cognitive function examination and presenting vital sign parameters. Asymptomatic patients (n = 451) did not receive GE. AC was administered to asymptomatic patients only on even days. GE in the remaining symptomatic patients (n = 357) was performed only on even days. On emptying days, alert patients had ipecac-induced emesis while obtunded patients received gastric lavage. AC therapy followed gastric emptying. On nonemptying days, symptomatic patients were treated only with AC. No clinical deterioration occurred in the asymptomatic patients treated without GE. AC use did not alter outcome measures in asymptomatic patients. GE procedures in symptomatic patients did not significantly alter the length of stay in the emergency department, mean length of time intubated, or mean length of stay in the intensive care unit. Gastric lavage was associated with a higher prevalence of medical intensive care unit admissions (P = .0001) and aspiration pneumonia (P = .0001). The data support the management of selected acute overdose patients without GE and fail to show a benefit from AC in asymptomatic overdose patients.

Enhanced isolation of Campylobacter jejuni by cold enrichment in Campy-thio broth

Isolation of Campylobacter jejuni from human feces by direct inoculation to Campy-BAP (Scott Laboratories, Inc., Fiskeville, R.I.) was compared with isolation after overnight enrichment at 4 degrees C in Campy-thio broth followed by subculture to Campy-BAP. Of 54 positive specimens, 19 were positive only after enrichment, and 5 were positive only on the direct plate. Among 36 positive patients, 10 were detected by enrichment only and 2 by direct plating only. Laboratories using Campy-BAP should include cold enrichment in Campy-thio broth for optimum recovery of C. jejuni.