Serum Procalcitonin (PCT) - Is there a Role as an Early Biomarker in Infected Diabetic Foot Ulcer (IDFU) Patients?

Introduction

Infected diabetic foot ulcers may lead to serious complications if not recognised in the early stage. Diagnosis of infection is particularly challenging at that stage; thus, a sensitive inflammatory biomarker may be helpful. We aimed to evaluate the role of procalcitonin (PCT) as an early biomarker for infected diabetic foot ulcers (IDFU).

Materials and method

This cross-sectional study was conducted at Klinik Rawatan Keluarga (KRK), Orthopedic clinic and wards in Hospital Universiti Sains Malaysia (USM) from May 2020 to December 2020. A total of 264 participants were recruited and divided into three groups: 50 diabetic patients with no ulcers (control), 107 patients with non-infected diabetic foot ulcers (NIDFU), and 107 patients with infected diabetic foot ulcers (IDFU). The level of PCT was taken for all patients. Total white count (TWC) and C-reactive protein (CRP) were taken only for IDFU patients. Diagnosis of infection was based on the Infectious Disease Society of America-International Working Group of Diabetic Foot (IDSA-IMWGDF), and the severity of infection was graded according to the Wagner Classification.

Results

The level of PCT was higher in IDFU than in NIDFU and diabetic patient, with a median (IQR) of 0.355 (0.63) ng/mL, 0.077 (0.15) ng/mL and 0.028 (0.02) ng/mL, respectively. PCT and CRP showed moderate positive correlations in IDFU patients (p<0.001). The sensitivity and specificity were 63.6% and 83.2%, respectively, at the best cut-off at 0.25 ng/mL.

Conclusion

PCT is a valuable biomarker for the diagnosis of infection; however, it adds little value in the early diagnosis of IDFU in view of its low sensitivity.

Erythropoietin Receptor (EPOR) Signaling in the Osteoclast Lineage Contributes to EPO-Induced Bone Loss in Mice

Erythropoietin (EPO) is a pleiotropic cytokine that classically drives erythropoiesis but can also induce bone loss by decreasing bone formation and increasing resorption. Deletion of the EPO receptor (EPOR) on osteoblasts or B cells partially mitigates the skeletal effects of EPO, thereby implicating a contribution by EPOR on other cell lineages. This study was designed to define the role of monocyte EPOR in EPO-mediated bone loss, by using two mouse lines with conditional deletion of EPOR in the monocytic lineage. Low-dose EPO attenuated the reduction in bone volume (BV/TV) in Cx3cr1^Cre EPOR^f/f female mice (27.05%) compared to controls (39.26%), but the difference was not statistically significant. To validate these findings, we increased the EPO dose in LysM^Cre model mice, a model more commonly used to target preosteoclasts. There was a significant reduction in both the increase in the proportion of bone marrow preosteoclasts (CD115⁺) observed following high-dose EPO administration and the resulting bone loss in LysM^Cre EPOR^f/f female mice (44.46% reduction in BV/TV) as compared to controls (77.28%), without interference with the erythropoietic activity. Our data suggest that EPOR in the monocytic lineage is at least partially responsible for driving the effect of EPO on bone mass.

Biochemical and structural insights into Rab12 interactions with RILP and its family members

Alongside its biosynthetic functions, the small GTPase Rab12 negatively regulates mast cell (MC) exocytosis by its interaction with RILP to promote retrograde transport of the MC secretory granules. Given the role of Rab effectors in mediating Rab functions, in this study we used biochemical and in silico tools to decipher Rab12 interactions with its RILP family effectors. We show that Rab12 interacts with RILP, RILP-L1 and RILP-L2 independently of each other, whereby lysine-71, in mouse Rab12, is critical for Rab12 interactions with RILP-L1 or RILP-L2, but is dispensable for the binding of RILP. Focusing on RILP, and relying on molecular dynamics simulations, functional mutational analyses and peptide inhibition assays, we propose a model for the Rab12-RILP complex, consisting of a RILP homodimer and a single molecule of active Rab12, that interacts with the RILP homology domain (RHD) of one RILP monomer and a C-terminal threonine in the other monomer via its switch I and switch II regions. Mutational analyses of RILP RHD also demonstrate its involvement in the regulation of MC secretory granule transport. Jointly, our results provide structural and functional insights into the Rab12-RILP complex on the basis of which new tools could be generated for decoding Rab12 functions.

Optimisation of asymmetric flow field-flow fractionation for the characterisation of nanoparticles in coated polydisperse TiO2 with applications in food and feed

Titanium dioxide (TiO₂) has various applications in consumer products and is also used as an additive in food and feeding stuffs. For the characterisation of this product, including the determination of nanoparticles, there is a strong need for the availability of corresponding methods of analysis. This paper presents an optimisation process for the characterisation of polydisperse-coated TiO₂ nanoparticles. As a first step, probe ultrasonication was optimised using a central composite design in which the amplitude and time were the selected variables to disperse, i.e., to break up agglomerates and/or aggregates of the material. The results showed that high amplitudes (60%) favoured a better dispersion and time was fixed in mid-values (5 min). In a next step, key factors of asymmetric flow field-flow fraction (AF4), namely cross-flow (CF), detector flow (DF), exponential decay of the cross-flow (CF_exp) and focus time (Ft), were studied through experimental design. Firstly, a full-factorial design was employed to establish the statistically significant factors (p < 0.05). Then, the information obtained from the full-factorial design was utilised by applying a central composite design to obtain the following optimum conditions of the system: CF, 1.6 ml min^–1; DF, 0.4 ml min^–1; Ft, 5 min; and CF_exp, 0.6. Once the optimum conditions were obtained, the stability of the dispersed sample was measured for 24 h by analysing 10 replicates with AF4 in order to assess the performance of the optimised dispersion protocol. Finally, the recovery of the optimised method, particle shape and particle size distribution were estimated.

Immunogenicity and Safety of the AS04-adjuvanted Human Papillomavirus-16/18 Cervical Cancer Vaccine in Malaysian Women Aged 18-35 years: A Randomized Controlled Trial

INTRODUCTION

Cervical cancer is the third most common cancer in women worldwide. The HPV-16/18 AS04- adjuvanted vaccine (Cervarix©) has previously been shown to be highly immunogenic with a clinically acceptable safety profile. This phase IIIb, double-blind, randomized (1:1) and placebo controlled trial (NCT00345878) was designed to evaluate the vaccine immunogenicity against HPV-16 and HPV-18 as well as its safety and reactogenicity in Malaysian women.

METHODS

Healthy women aged 18-35 years received intramuscularly three doses of either the vaccine (HPV group) or aluminium hydroxide (ALU group) at 0, 1, and 6 months. Antibody titers were measured by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

A total of 271 eligible subjects were enrolled and 266 subjects completed the study. Initially seronegative subjects in the HPV group showed 100% seroconversion one month post-dose-3 for anti HPV-16 and anti-HPV-18 antibodies with geometric mean titers of 11107.5 (95% CI: 9727.3-12683.4) EL.U/mL and 4273.5 (95% CI: 3771.8-4841.9) EL.U/mL, respectively. Over 96% of subjects in both groups received all three vaccine doses. Solicited local (pain) and general symptoms (myalgia, fatigue, arthralgia and headache) were commonly reported in both HPV and ALU groups. Eight serious adverse events were reported throughout the study (five in the HPV group; three in the ALU group), all considered by investigators to be unrelated to vaccination.

CONCLUSION

The HPV-16/18 AS04-adjuvanted vaccine was immunogenic and generally well tolerated in Malaysian women aged 18-35 years.

Bacterial endocarditis and orthodontics

The purpose of this article is to discuss the prevalence and intensity of bacteraemia associated with orthodontic procedures and help formulate practical guidelines for orthodontists treating children with congenital or acquired heart disease. Preliminary results demonstrate a significant increase in the intensity of bacteraemia from baseline following insertion of an orthodontic separator. The potential for development of bacterial endocarditis (BE) is extremely low, questioning the need for antibiotic prophylaxis for procedures other than extractions. However, for patients who are 'at risk' a very high standard of oral hygiene is essential and much of the responsibility lies with the individual patients to learn to protect themselves.

The control of the free-living stages of Strongyloides papillosus by the nematophagous fungus, Arthrobotrys oligospora

Two laboratory trials were conducted to determine the effect of the addition of spores (conidia) of the nematophagous fungus, Arthrobotrys oligospora, on the development of the ruminant parasite, Strongyloides papillosus, in cultures of bovine faeces. Both studies showed that at a concentration of 2000 conidia/g faeces virtually eliminated infective larvae (> 99% reduction), following 14 days incubation under ideal conditions (25 degrees C and saturated humidity) for free-living development of this parasite species. In one trial, a high level of control was also observed at a 10-fold decrease in conidia concentration (200 spores/g faeces). This work has demonstrated, in principle, that A. oligospora could provide a practical biological control agent against S. papillosus infecting intensively raised young ruminants in the humid tropics/subtropics.

The aetiology of severe community-acquired pneumonia and its impact on initial, empiric, antimicrobial chemotherapy

Of 259 patients admitted to an intensive care unit with severe acute community-acquired pneumonia, 173 had primary infections and 86 had secondary infections. The commonest organism isolated in each group was Streptococcus pneumoniae (51.3 and 36.6% of known isolates in each group respectively). Klebsiella pneumoniae was the next most common isolate (31.9 and 29.3% respectively). A variety of other Gram-negative organisms and Staphylococcus aureus accounted for most of the remaining pathogens. Based on retrospective analysis of data, there appeared to be no difference in the alcohol consumption of patients with infection due to S. pneumoniae and K. pneumoniae. The overall mortality rate for the primary infections was 47.4%, with 68.4% of these infections due to K. pneumoniae and 33.9% due to the pneumococcus (P < 0.002). Among the secondary infections, the overall mortality rate was 40.8% (not significantly different to that of primary infections) with 45.5% due to K. pneumoniae and 23.1% due to the pneumococcus (not significantly different on statistical analysis, probably due to low patient numbers). Our investigation confirms that severe community-acquired pneumonia due to K. pneumoniae is extremely common, even in patients without obvious risk factors for Gram-negative colonization. This organism is contributing to the high mortality rate seen in our intensive care unit among patients with pneumonia, and our empiric therapy for such cases routinely includes a combination of agents active against this organism (e.g. a cephalosporin and an aminoglycoside).