Karl Bremer Hospital

Mitochondrial bioenergetics of PBMCs have been linked with several factors that contribute to a better understanding of several human diseases. Due to the complex logistics of clinical studies, samples are often cryopreserved for later analysis. Current data on whether cryopreservation negatively affects the mitochondrial function of PBMCs is discrepant. We isolated and cryopreserved peripheral blood mononuclear cells (PBMCs) from human whole blood and tested mitochondrial function using a substrate-uncoupler-inhibitor-titration protocol on the Oroboros instrument. After three months of storage in a cryopreservation medium (at -80°C), several aspects of mitochondrial bioenergetics were measured. We demonstrate that cryopreservation did not adversely affect mitochondrial parameters (routine, leak, complex-I linked OXPHOS, cytochrome-c response, ETS capacity, the contributions of the N and S-pathways to ETS, ROX, complex-IV activity and mitochondrial coupling). Therefore, after three months of cryopreservation at -80°C, human PBMC-mitochondria were fully coupled and functional. Therefore, clinical studies may cryopreserve PBMCs for later mitochondrial analyses.

We draw attention to a less well-known complication of hydatid disease.

Children have an increased risk of developing radiation-induced secondary malignancies compared to adults, due to their high radiosensitivity and longer life expectancy. In contrast to the epidemiological evidence, there is only a handful of radiobiology studies which investigate the difference in radiosensitivity between children and adults at a cellular level. In this study, the previous results on the potential age dependency in chromosomal radiosensitivity were validated again by means of the cytokinesis-block micronucleus (CBMN) assay in T-lymphocytes isolated from the umbilical cord and adult peripheral blood of a South African population. The isolated cells were irradiated with 60Co γ-rays at doses ranging from 0.5 Gy to 4 Gy. Increased radiosensitivities of 34%, 42%, 29%, 26% and 16% were observed for newborns compared to adults at 0.5, 1, 2, 3 and 4 Gy, respectively. An immunophenotypic evaluation with flow cytometry revealed a significant change in the fraction of naïve (CD45RA+) T-lymphocytes in CD4+ and CD8+ T-lymphocytes with age. Newborns co-expressed an average of 91.05% CD45RA+ (range: 80.80–98.40%) of their CD4+ cells, while this fraction decreased to an average of 39.08% (range: 12.70–58.90%) for adults. Similar observations were made for CD8+ cells. This agrees with previous published results that the observed differences in chromosomal radiosensitivity between newborn and adult T-lymphocytes could potentially be linked to their immunophenotypic profiles.

The radiosensitivity of haematopoietic stem and progenitor cells (HSPCs) to neutron radiation remains largely underexplored, notwithstanding their potential role as target cells for radiation-induced leukemogenesis. New insights are required for radiation protection purposes, particularly for aviation, space missions, nuclear accidents and even particle therapy. In this study, HSPCs (CD34+CD38+ cells) were isolated from umbilical cord blood and irradiated with 60Co γ-rays (photons) and high energy p(66)/Be(40) neutrons. At 2 h post-irradiation, a significantly higher number of 1.28 ± 0.12 γ-H2AX foci/cell was observed after 0.5 Gy neutrons compared to 0.84 ± 0.14 foci/cell for photons, but this decreased to similar levels for both radiation qualities after 18 h. However, a significant difference in late apoptosis was observed with Annexin-V+/PI+ assay between photon and neutron irradiation at 18 h, 43.17 ± 6.10% versus 55.55 ± 4.87%, respectively. A significant increase in MN frequency was observed after both 0.5 and 1 Gy neutron irradiation compared to photons illustrating higher levels of neutron-induced cytogenetic damage, while there was no difference in the nuclear division index between both radiation qualities. The results point towards a higher induction of DNA damage after neutron irradiation in HSPCs followed by error-prone DNA repair, which contributes to genomic instability and a higher risk of leukemogenesis.

IntroductionTraditional vital signs are seen as an important part of trauma assessment, despite their poor predictive value in this regard.ObjectiveThis study evaluated whether the difference between systolic blood pressure (SBP), heart rate (HR), respiratory rate (RR) and shock index (SI) taken in the emergency department (ED) and prehospital can predict 48 h mortality postadmission following trauma.MethodsRetrospective cohort was obtained from the Trauma Audit and Research Network. Subjects were excluded if head or spinal injuries, prehospital intubation or CPR were present. Main outcome was 48 h mortality. The difference (delta, Δ) between ED and prehospital values were used as study variables (ie, ΔSI=SI-ED minus SI-prehospital). Accuracy was assessed using area under receiver operator characteristic curve (AUROC). AUROC coordinates were used to identify 95% specificity cut points and described further using sensitivity and likelihood ratios (LRs).ResultsSignificant AUROC statistics were revealed for ΔSBP (0.57) and ΔRR (0.56) for the full sample, ΔSBP (0.62) and ΔSI (0.65) for moderate, and ΔRR (0.6) for severe injury. Best LRs were 3.4 and 2.4 for ΔRR and ΔSI, respectively, but sensitivities were low (<=26%). Cut point values for ΔSBP, ΔRR and ΔSI were 37 mm Hg, 8 breaths/min and 0.2, respectively.DiscussionΔSBP and ΔRR performed best overall, but ΔSI performed best in the moderate injury group, suggesting earlier identification with ΔSI. Use of Δ values result in good rule-in of 48 h mortality and may supplement trauma treatment decisions.

BackgroundRaised blood pressure (and heart rate (HR)) due to anxiety in a clinical situation is well described and is called the white coat effect (WCE). It is not known whether the pain and anxiety that results from trauma causes a measurable WCE.MethodsA sample of patients with a non-haemorrhagic injury from the Trauma Audit and Research Network (TARN) was compared with a healthy, non-injury sample from the Health Survey for England (HSE) databases. Two-way analysis of variance with rank transformation of data was used to compare systolic blood pressure (SBP) and HR between the groups at different ages. In the injured group, the SBP and HR were also compared between spinally immobilised and non-immobilised patients.ResultsThere was a statistically significant difference between the groups for both HR and SBP (p<0.001). Median HR remained approximately 10 bpm higher in the TARN set when compared to the HSE set, irrespective of age. The difference for SBP was not considered clinically relevant (the highest was 5 mm Hg). There was no significant difference between immobilised and non-immobilised patients, for either HR or SBP (p=0.07 and 0.3, respectively).DiscussionMedian HR remained approximately 10 bpm higher in the TARN (injury) set compared to the HSE (non-injury, control) set, irrespective of age. Understanding that HR reacts in this way for mild to moderately injured patients is important as it will affect clinical interpretation during the initial assessment.

PA-824 is a novel nitroimidazo-oxazine under evaluation as an antituberculosis agent. A dose-ranging randomized study was conducted to evaluate the safety, tolerability, pharmacokinetics, and early bactericidal activity of PA-824 in drug-sensitive, sputum smear-positive adult pulmonary-tuberculosis patients to find the lowest dose giving optimal bactericidal activity (EBA). Fifteen patients per cohort received oral PA-824 in doses of 50 mg, 100 mg, 150 mg, or 200 mg per kg body weight per day for 14 days. Eight subjects received once-daily standard antituberculosis treatment with isoniazid, rifampin, pyrazinamide, and ethambutol (HRZE) as a positive control. The primary efficacy endpoint was the mean rate of decline in log CFU of Mycobacterium tuberculosis in sputum incubated on agar plates from serial overnight sputum collections, expressed as log(10) CFU/day/ml sputum (± standard deviation). The mean 14-day EBA of HRZE was consistent with previous studies (0.177 ± 0.042), and that of PA-824 at 50 mg, 100 mg, 150 mg, and 200 mg was 0.063 ± 0.058, 0.091 ± 0.073, 0.078 ± 0.074, and 0.112 ± 0.070, respectively. Although the study was not powered for testing the difference between arms, there was a trend toward significance, indicating a lower EBA at the 50-mg dose. Serum PA-824 levels were approximately dose proportional with respect to the area under the time-concentration curve. All doses were safe and well tolerated with no dose-limiting adverse events or clinically significant QTc changes. A dose of 100 mg to 200 mg PA-824 daily appears to be safe and efficacious and will be further evaluated as a component of novel antituberculosis regimens for drug-sensitive and drug-resistant tuberculosis.

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