Fetal median sacral artery anatomy study by micro-CT imaging

PURPOSE

The median sacral artery (MSA) is the termination of the dorsal aorta, which undergoes a complex regression and remodeling process during embryo and fetal development. The MSA contributes to the pelvic vascularization and may be injured during pelvic surgery. The embryological steps of MSA development, anastomosis formation and anatomical variations are linked, but not fully understood.

METHODS

The pelvic vascularization and more precisely the MSA of a human fetus at 22 weeks of gestation (GW) were studied using micro-CT imaging. Image treatment included arterial segmentations and 3D visualization.

RESULTS

At 22 GW, the MSA was a well-developed straight artery in front of the sacrum and was longer than the abdominal aorta. Anastomoses between the MSA and the internal pudendal arteries and the superior rectal artery were detected. No evidence was found for the existence of a coccygeal glomus with arteriovenous anastomosis.

CONCLUSIONS

Micro-CT imaging and 3D visualization helped us understand the MSA central role in pelvic vascularization through the ilio-aortic anastomotic system. It is essential to know this anastomotic network to treat pathological conditions, such as sacrococcygeal teratomas and parasitic ischiopagus twins (for instance, fetus in fetu and twin-reversed arterial perfusion sequence).

The position of a written document in preoperative information for pediatric surgery: A randomized controlled trial on parental anxiety, knowledge, and satisfaction

INTRODUCTION

Preoperative information is a legal and ethical obligation. Very little studies have evaluated the preoperative information method in pediatrics. Having a child operated on is stressful for the parents. Improving information is a way to lower their anxiety. Our study aims to measure the impact of a leaflet, which supports spoken information on parental anxiety, the comprehension-memorization of the information and their satisfaction.

MATERIALS & METHODS

Prospective study including 178 patients of outpatient surgery, randomized in two groups: spoken information versus spoken information supported by a leaflet, which is then handed out to the parents. The messages were identical: physiopathology, risks without treatment, surgical technique and its possible complications, description of the hospitalization day, and postoperative care. Parental evaluation was made with self-questionnaires after the preoperative consultation, then on the day of surgery. At each moment we evaluated the level of anxiety, satisfaction of information quality and the comprehension-memorization of the data.

RESULTS

Written information significantly improves the scores of comprehension-memorization, parental satisfaction and significantly decreases the level of anxiety.

CONCLUSION

Significant impact of the written document as communication support in pediatric surgery, validating the method and encouraging it to be generalized to other pediatric surgery acts.

LEVEL OF EVIDENCE

Level I.

TYPE OF STUDY

Prognosis study.

Escape of anions from geminate recombination in THF due to charge delocalization

Geminate recombination of 24 radical anions (M˙^-) with solvated protons (RH₂⁺) was studied in tetrahydrofuran (THF) with pulse radiolysis. The recombination has two steps: (1) diffusion of M˙^- and RH₂⁺ together to form intimate (contact and solvent separated) ion pairs, driven by Coulomb attraction; (2) annihilation of anions due to proton transfer (PT) from RH₂⁺ to M˙^-. The non-exponential time-dependence of the geminate diffusion was determined. For all molecules protonated on O or N atoms the subsequent PT step is too fast (<0.2 ns) to measure, except for the anion of TCNE which did not undergo proton transfer. PT to C atoms was as slow as 70 ns and was always slow enough to be observable. A possible effect of charge delocalization on the PT rates could not be clearly separated from other factors. For 21 of the 24 molecules studied here, a free ion yield (71.6 ± 6.2 nmol J^-1) comprising ∼29% of the total, was formed. This yield of "Type I" free ions is independent of the PT rate because it arises entirely by escape from the initial distribution of ion pair distances without forming intimate ion pairs. Three anions of oligo(9,9-dihexyl)fluorenes, F_n˙^- (n = 2-4) were able to escape from intimate ion-pairs to form additional yields of "Type II" free ions with escape rate constants near 3 × 10⁶ s^-1. These experiments find no evidence for an inverted region for proton transfer.

Correction: Escape of anions from geminate recombination in THF due to charge delocalization

Correction for ‘Escape of anions from geminate recombination in THF due to charge delocalization’ by Hung-Cheng Chen et al., Phys. Chem. Chem. Phys., 2017, 19, 32272–32285.

The efficacy of HI-6 DMS in a sustained infusion against percutaneous VX poisoning in the guinea-pig

Post-exposure nerve agent treatment usually includes administration of an oxime, which acts to restore function of the enzyme acetylcholinesterase (AChE). For immediate treatment of military personnel, this is usually administered with an autoinjector device, or devices containing the oxime such as pralidoxime, atropine and diazepam. In addition to the autoinjector, it is likely that personnel exposed to nerve agents, particularly by the percutaneous route, will require further treatment at medical facilities. As such, there is a need to understand the relationship between dose rate, plasma concentration, reactivation of AChE activity and efficacy, to provide supporting evidence for oxime infusions in nerve agent poisoning. Here, it has been demonstrated that intravenous infusion of HI-6, in combination with atropine, is efficacious against a percutaneous VX challenge in the conscious male Dunkin-Hartley guinea-pig. Inclusion of HI-6, in addition to atropine in the treatment, improved survival when compared to atropine alone. Additionally, erythrocyte AChE activity following poisoning was found to be dose dependent, with an increased dose rate of HI-6 (0.48mg/kg/min) resulting in increased AChE activity. As far as we are aware, this is the first study to correlate the pharmacokinetic profile of HI-6 with both its pharmacodynamic action of reactivating nerve agent inhibited AChE and with its efficacy against a persistent nerve agent exposure challenge in the same conscious animal.

[Impact of a written document for preoperative information on the use of Internet by parents]

INTRODUCTION

Preoperative information is a legal and ethical obligation. Very few studies have evaluated the preoperative information method in pediatrics. Having a child operated on is stressful for parents. The use of Internet to look for data on the pathology and its treatment is frequent, but often unprofitable and sometimes even harmful. This study aimed to measure the impact of a leaflet, which supports spoken information in preoperative consultation, on parents' use of the Internet before surgery.

MATERIAL AND METHODS

Prospective study including 178 patients of outpatient surgery, randomized into two groups: spoken information alone versus spoken information supported by a personalized leaflet, which is then handed out to the parents. The messages were identical: physiopathology, risks without treatment, surgical technique, possible complications, description of the hospitalization day, and postoperative care. Parental evaluation was carried out with self-administered questionnaires after the preoperative consultation, then on the day of surgery. At each moment the rate of Internet use, its reasons, and the benefits were evaluated.

RESULTS

The written document significantly reduced the use of the Internet by parents regardless of the child's age, their degree of anxiety, their level of understanding, and the time between consultation and the intervention.

CONCLUSION

This study confirms the significant impact of the leaflet as a communication tool in pediatric surgery and the substantial utility for parents. This encourages us to generalize this method to other pediatric surgery acts.

High pressure balloon dilatation of the ureterovesical junction in primary obstructive megaureter: Infectious morbidity

INTRODUCTION

The objective of this study is to investigate the infectious morbidity associated with high-pressure balloon dilatation (HPBD) and an indwelling double J stent, in primary obstructive megaureter.

METHODS

We reviewed the cases of 12 patients undergoing endoscopic treatment for primary obstructive megaureter from January 2012 to January 2015. The characteristics of the infection and data concerning the patient and the intervention were analyzed.

RESULTS

The frequency of preoperative urinary tract infection (UTI) was 58%. The procedure was feasible in 100% of cases. Two patients required a second dilatation. One patient underwent Cohen's ureteral reimplantation after failure of the second dilatation. The frequency of postoperative UTI was 25%. All these infections occurred in patients with a double J stent. None of the patients had UTI after stent removal. None of the patients developed postoperative vesicoureteral reflux (VUR) after HPBD.

CONCLUSION

Endoscopic balloon dilatation has been shown to have good short- mid- and long-term outcomes. In our experience, the morbidity of this procedure mostly results from infections, exclusively related to the use of a double J stent. The placement of a double J stent has a significant medical and economic impact. A definitive decision about the utility of double J stents will require studies of further dilatation without the placement of a double J stent.

LEVEL OF EVIDENCE

4.

Assessment of the Effects of MPTP and Paraquat on Dopaminergic Neurons and Microglia in the Substantia Nigra Pars Compacta of C57BL/6 Mice

The neurotoxicity of paraquat dichloride (PQ) was assessed in two inbred strains of 9- or 16-week old male C57BL/6 mice housed in two different laboratories and compared to the effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). PQ was administered by intraperitoneal injections; either once (20 mg/kg) or twice (10 mg/kg) weekly for 3 weeks, while MPTP-HCl was injected 4 times on a single day (20 mg/kg/dose). Brains were collected 8, 16, 24, 48, 96 or 168 hours after the last PQ treatment, and 48 or 168 hours after MPTP treatment. Dopamine neurons in the substantia nigra pars compacta (SNpc) were identified by antibodies to tyrosine hydroxylase (TH⁺) and microglia were identified using Iba-1 immunoreactivity. The total number of TH⁺ neurons and the number of resting and activated microglia in the SNpc at 168 hours after the last dose were estimated using model- or design-based stereology, with investigators blinded to treatment. In a further analysis, a pathologist, also blinded to treatment, evaluated the SNpc and/or striatum for loss of TH⁺ neurons (SNpc) or terminals (striatum), cell death (as indicated by amino cupric silver uptake, TUNEL and/or caspase 3 staining) and neuroinflammation (as indicated by Iba-1 and/or GFAP staining). PQ, administered either once or twice weekly to 9- or 16-week old mice from two suppliers, had no effect on the number of TH⁺ neurons or microglia in the SNpc, as assessed by two groups, each blinded to treatment, using different stereological methods. PQ did not induce neuronal cell loss or degeneration in the SNpc or striatum. Additionally, there was no evidence of apoptosis, microgliosis or astrogliosis. In MPTP-treated mice, the number of TH⁺ neurons in the SNpc was significantly decreased and the number of activated microglia increased. Histopathological assessment found degenerating neurons/terminals in the SNpc and striatum but no evidence of apoptotic cell death. MPTP activated microglia in the SNpc and increased the number of astrocytes in the SNpc and striatum.

Comparison of Infrared Thermal Detection Systems for mass fever screening in a tropical healthcare setting

Objectives

Fever screening systems, such as Infrared Thermal Detection Systems (ITDS), have been used for rapid identification of potential cases during respiratory disease outbreaks for public health management. ITDS detect a difference between the subject and ambient temperature, making deployment in hot climates more challenging. This study, conducted in Singapore, a tropical city, evaluates the accuracy of three different ITDS for fever detection compared with traditional oral thermometry and self-reporting in a clinical setting.

Study design

This study is a prospective operational evaluation conducted in the Singapore military on all personnel seeking medical care at a high-volume primary healthcare centre over a one week period in February 2014.

Methods

Three ITDS, the STE Infrared Fever Screening System (IFSS), the Omnisense Sentry MKIII and the handheld Quick Shot Infrared Thermoscope HT-F03B, were evaluated. Temperature measurements were taken outside the healthcare centre, under a sheltered walkway and compared to oral temperature. Subjects were asked if they had fever.

Results

There were 430 subjects screened, of whom 34 participants (7.9%) had confirmed fever, determined by oral thermometer measurement. The handheld infrared thermoscope had a very low sensitivity (29.4%), but a high specificity (96.8%). The STE ITDS had a moderate sensitivity (44.1%), but a very high specificity (99.1%). Self-reported fevers showed good sensitivity (88.2%) and specificity (93.9%). The sensitivity of the Omnisense ITDS (89.7%) was the highest among the three methods with good specificity (92.0%).

Conclusion

The new generation Omnisense ITDS displayed a relatively high sensitivity and specificity for fever. Though it has a lower sensitivity, the old generation STE ITDS system showed a very high specificity. Self-reporting of fever was reliable. The handheld thermograph should not be used as a fever-screening tool under tropical conditions.

•

The new generation fever screening system displayed a relatively high sensitivity and specificity for fever.

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Self-reporting of fever was reliable compared to measured temperature.

•

The handheld thermograph should not be used as a fever-screening tool under tropical conditions.

Performance of case definitions for influenza surveillance

Influenza-like illness (ILI) case definitions, such as those from the European Centre for Disease Control and Prevention, World Health Organization (WHO) and United States Centers for Disease Control and Prevention, are commonly used for influenza surveillance. We assessed how various case definitions performed during the initial wave of influenza A(H1N1) pdm09 infections in Singapore on a cohort of 727 patients with two to three blood samples and whose symptoms were reviewed fortnightly from June to October 2009. Using seroconversion (≥ 4-fold rise) to A/California/7/2009 (H1N1), we identified 36 presumptive influenza A(H1N1)pdm09 episodes and 664 episodes unrelated to influenza A(H1N1)pdm09. Cough, fever and headache occurred more commonly in presumptive influenza A(H1N1)pdm09. Although the sensitivity was low (36%), the recently revised WHO ILI case definition gave a higher positive predictive value (42%) and positive likelihood ratio (13.3) than the other case definitions. Results including only episodes with primary care consultations were similar. Individuals who worked or had episodes with fever, cough or sore throat were more likely to consult a physician, while episodes with Saturday onset were less likely, with some consultations skipped or postponed. Our analysis supports the use of the revised WHO ILI case definition, which includes only cough in the presence of fever defined as body temperature ≥ 38 °C for influenza surveillance.

Dietary administration of paraquat for 13 weeks does not result in a loss of dopaminergic neurons in the substantia nigra of C57BL/6J mice

Several investigations have reported that mice administered paraquat dichloride (PQ·Cl2) by intraperitoneal injection exhibit a loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). In this study, male and female C57BL/6J mice were administered PQ·Cl2 in the diet at concentrations of 0 (control), 10, and 50ppm for a duration of 13weeks. A separate group of mice were administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) during week 12 as positive controls to produce a loss of dopaminergic neurons in the SNpc. The comparative effects of PQ and MPTP on the SNpc and/or striatum were assessed using neurochemical, neuropathological, and stereological endpoints. Morphological and stereological assessments were performed by investigators 'blinded' to the origin of the tissue. Neither dose of PQ·Cl2 (10 or 50 ppm in the diet) caused a loss of striatal dopamine or dopamine metabolite concentrations in the brains of mice. Pathological assessments of the SNpc and striatum showed no evidence of neuronal degeneration or astrocytic/microglial activation. Furthermore, the number of tyrosine hydroxylase-positive (TH(+)) neurons in the SNpc was not reduced in PQ-treated mice. In contrast, MPTP caused a decrease in striatal dopamine concentration, a reduction in TH(+) neurons in the SNpc, and significant pathological changes including astrocytic and microglial activation in the striatum and SNpc. The MPTP-induced effects were greater in males than in females. It is concluded that 13weeks of continuous dietary exposure of C57BL/6J mice to 50ppm PQ·Cl2 (equivalent to 10.2 and 15.6mg PQ ion/kg body weight/day for males and females, respectively) does not result in the loss of, or damage to, dopaminergic neurons in the SNpc.

Sustained meticillin-resistant Staphylococcus aureus control in a hyper-endemic tertiary acute care hospital with infrastructure challenges in Singapore

Background

Meticillin-resistant Staphylococcus aureus (MRSA) has been entrenched in Singapore hospitals since the 1980s, with an excess of 600 non-duplicate cases of infections (120 bacteraemia episodes) each year in our 995-bed university hospital. Approximately 5% of our hospital beds are used as isolation facilities.

Aim

To study the impact of an MRSA control bundle that was implemented via gradual geographic extension across hospital wards.

Methods

The bundle included active surveillance on admission and transfer/discharge to identify ward-based acquisition of MRSA, isolation and cohorting of MRSA-infected patients, enhanced hand hygiene initiatives, and publicly displayed feedback of MRSA acquisition and hand hygiene compliance rates. Implementation was between October 2006 and June 2010 in order to provide lead-time for the incremental development of infrastructural capacity, and to develop an ethic of infection prevention among staff. Results were analysed via interrupted time-series analysis.

Findings

MRSA infections fell midway through the implementation, with MRSA bacteraemia declining from 0.26 [95% confidence interval (CI): 0.18–0.34] cases per 1000 inpatient-days in the first quarter of 2004 to 0.11 (95% CI: 0.07–0.19) cases per 1000 inpatient-days in the first quarter of 2012. MRSA acquisition rates fell a year after the programme had been fully implemented, whereas hand hygiene compliance rose significantly from 47% (95% CI: 44–49) in the first quarter of 2009 to 69% (95% CI: 68–71) in the first quarter of 2012.

Conclusion

Successful staged implementation of an MRSA bundle in a hyper-endemic setting is sustainable and represents a model that may be adapted for similar settings.

Pharmacokinetic, neurochemical, stereological and neuropathological studies on the potential effects of paraquat in the substantia nigra pars compacta and striatum of male C57BL/6J mice

The pharmacokinetics and neurotoxicity of paraquat dichloride (PQ) were assessed following once weekly administration to C57BL/6J male mice by intraperitoneal injection for 1, 2 or 3 weeks at doses of 10, 15 or 25 mg/kg/week. Approximately 0.3% of the administered dose was taken up by the brain and was slowly eliminated, with a half-life of approximately 3 weeks. PQ did not alter the concentration of dopamine (DA), homovanillic acid (HVA) or 3,4-dihydroxyphenylacetic acid (DOPAC), or increase dopamine turnover in the striatum. There was inconsistent stereological evidence of a loss of DA neurons, as identified by chromogenic or fluorescent-tagged antibodies to tyrosine hydroxylase in the substantia nigra pars compacta (SNpc). There was no evidence that PQ induced neuronal degeneration in the SNpc or degenerating neuronal processes in the striatum, as indicated by the absence of uptake of silver stain or reduced immunolabeling of tyrosine-hydroxylase-positive (TH(+)) neurons. There was no evidence of apoptotic cell death, which was evaluated using TUNEL or caspase 3 assays. Microglia (IBA-1 immunoreactivity) and astrocytes (GFAP immunoreactivity) were not activated in PQ-treated mice 4, 8, 16, 24, 48, 96 or 168 h after 1, 2 or 3 doses of PQ. In contrast, mice dosed with the positive control substance, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 10mg/kg/dose×4 doses, 2 h apart), displayed significantly reduced DA and DOPAC concentrations and increased DA turnover in the striatum 7 days after dosing. The number of TH(+) neurons in the SNpc was reduced, and there were increased numbers of degenerating neurons and neuronal processes in the SNpc and striatum. MPTP-mediated cell death was not attributed to apoptosis. MPTP activated microglia and astrocytes within 4 h of the last dose, reaching a peak within 48 h. The microglial response ended by 96 h in the SNpc, but the astrocytic response continued through 168 h in the striatum. These results bring into question previous published stereological studies that report loss of TH(+) neurons in the SNpc of PQ-treated mice. This study also suggests that even if the reduction in TH(+) neurons reported by others occurs in PQ-treated mice, this apparent phenotypic change is unaccompanied by neuronal cell death or by modification of dopamine levels in the striatum.