Facial nerve communication with ansa cervicalis - An unusual anatomical variation

Neural connections of the seventh cranial nerve with its neighboring nerves are common and well documented; however, communication with ansa cervicalis is as yet unknown. We present a case with such a connection found during cadaveric dissection, with hitherto unknown consequences. In this specimen, after giving the marginal mandibular and cervical branches, the cervicofacial division continued distally to communicate with the distal loop of ansa cervicalis. Presence of such connection may result in facial muscle paralysis on injury to the ansa or strap muscle paralysis on injury to the facial nerve, depending on the direction of nerve fibers. Such unusual connections bring to light the need for extreme care during surgeries in the neck to safeguard any such connections and when using the ansa as donor.

Glyphosate, AMPA and glufosinate in soils and earthworms in a French arable landscape

Although Glyphosate-based herbicides are often marketed as environmentally friendly and easily biodegradable, its bioavailability and risks to wildlife raise significant concerns. Among non-target organisms, earthworms which live in close contact with the soil can be directly exposed to pesticides and harmed. We investigated soil contamination and the exposure of earthworms to glyphosate, its metabolite AMPA, and glufosinate in an arable landscape in France, both in treated (i.e. temporary grasslands and cereal fields under conventional farming), and nontreated habitats (i.e. hedgerows, permanent grasslands and cereal fields under organic farming) (n = 120 sampling sites in total). Glyphosate, AMPA and glufosinate were detected in 88%, 58% and 35% of the soil samples, and in 74%, 38% and 12% of the earthworm samples, respectively. For both glyphosate and AMPA, concentrations in soils were at least 10 times lower than predicted environmental concentrations. However, the maximum glyphosate soil concentration measured (i.e., 0.598 mg kg-1) was only 2 to 3 times lower than the concentrations revealed to affect earthworms (survival and avoidance) in the literature. These compounds were found both in conventional and organic farming fields, thus supporting a recent study, and for the first time they were detected in hedgerows and grasslands. However, glyphosate and AMPA were more frequently detected in soils from cereal fields and hedgerows than in grasslands, and median concentrations measured in soils from cereal fields were significantly higher than in the two other habitats. Bioaccumulation of glyphosate and AMPA in earthworms was higher than expected according to the properties of the molecules. Our findings raised issues about the high occurrence of glyphosate and AMPA in soils from cropped and more natural areas in arable landscapes. They also highlight the potential for transfer of these molecules in terrestrial food webs as earthworms are prey for numerous animals.

Orthopaedic assessment unit: a service model for the delivery of orthopaedic trauma care in a major trauma centre during the global pandemic (COVID-19)

INTRODUCTION

We describe a new service model, the Orthopaedic Assessment Unit (OAU), designed to provide care for trauma patients during the COVID-19 pandemic. Patients without COVID-19 symptoms and isolated musculoskeletal injuries were redirected to the OAU.

METHODS

We prospectively reviewed patients throughput during the peak of the global pandemic (7 May 2020 to 7 June 2020) and compared with our historic service provision (7 May 2019 to 7 June 2019). The Mann-Whitney and Fisher Exact tests were used to test the statistical significance of data.

RESULTS

A total of 1,147 patients were seen, with peak attendances between 11am and 2pm; 96% of all referrals were seen within 4h. The majority of patients were seen by orthopaedic registrars (52%) and nurse practitioners (44%). The majority of patients suffered from sprains and strains (39%), followed by fractures (22%) and wounds (20%); 73% of patients were discharged on the same day, 15% given follow up, 8% underwent surgery and 3% were admitted but did not undergo surgery. Our volume of trauma admissions and theatre cases decreased by 22% and 17%, respectively (p=0.058; 0.139). There was a significant reduction of virtual fracture clinic referrals after reconfiguration of services (p<0.001).

CONCLUSIONS

Rapid implementation of a specialist OAU during a pandemic can provide early definitive trauma care while exceeding national waiting time standards. The fall in trauma attendances was lower than anticipated. The retention of orthopaedic staff in the department to staff the unit and maintain a high standard of care is imperative.

Clinical outcome and predictors of severity in scrub typhus patients at a tertiary care hospital in Chandigarh, India

BACKGROUND & OBJECTIVES

Scrub typhus is an under-reported rickettsial illness caused by Orientia tsutsugamushi which is transmitted by trombiculid mites. Serious complications are not uncommon and multiorgan dysfunction may develop leading to death. Paucity of data on the clinical spectrum and determinants of aftermath may be contributing to higher mortality in the region. A prospective study was done to describe the spectrum of organ dysfunction in serologically confirmed cases of scrub typhus and document predictors of adverse outcomes.

METHODS

This prospective study was carried out in patients diagnosed to have scrub typhus by IgM ELISA. The clinical features, investigations and complications among survivors were statistically compared to those in the deceased. Fisher's exact test, t-test and logistic regression have been applied where appropriate.

RESULTS

The study population comprised of 123 patients. Majority of patients (62%) had one or more organ dysfunction. Ten patients (8.1%) did not survive. Complications documented were acute kidney injury (AKI) in 35%, hepatitis in 29.2%, acute respiratory distress syndrome (ARDS) in 26%, shock in 13%, meningitis in 5.7%, disseminated intravascular coagulation (DIC) in 2.6%, pancreatitis in 2.6% and myocarditis in 1.6%. Certain clinical features, biochemical parameters and complications had statistically significant correlation with the outcome. The mean SOFA score was considerably higher in those who did not survive. Interpretation &conclusion: Patients developing hepatic dysfunction, acute kidney injury and respiratory distress should be identified early and intensively monitored. The SOFA score can be utilized to assess the severity at admission and rapidly triage the sicker patients.

Negative pressure wound therapy versus gauze dressings for the treatment of contaminated traumatic wounds

OBJECTIVE

This compares hospital suction negative pressure wound therapy (NPWT) with conventional gauze dressings in traumatic soft-tissue injury at a tertiary care centre.

METHODS

A prospective control study was conducted between September 2012 and November 2014. Patients with one or more traumatic soft-tissue injuries with contaminated wounds were allocated to either a test group (received NPWT) or control group (received conventional gauze). Wounds were assessed by two orthopaedic surgeons. If grade A was achieved, the wound was covered with split-thickness skin graft, flap or delayed primary closure; otherwise, revision debridement and NPWT/saline gauze dressings were applied. Descriptive statistics (mean, standard deviation and proportions) were used to summarise the study variables. The 95% confidence intervals (CI) for difference of mean were used. Chi-square test and Fisher's exact test were used to observe an association between the qualitative data and outcome variables. Unpaired T-Test and Mann-Whitney U test were used for analysis of the quantitative data. A p<0.05 was considered statistically significant.

RESULTS

A total of 104 patients were included. The mean number of dressings per patient was significantly lower in the NPWT group (3.4) than in the control group (20.7) (p<0.001). The time between injury and complete closure (12.5 versus 21.4 days) as well as duration of hospital stay (17.3 versus 23.8 days) was significantly less in the NPWT group (p<0.05).

CONCLUSION

NPWT has a role in healing traumatic wounds and can be delivered effectively through hospital suction NPWT, which can also reduce the cost of therapy. We recommend its regular use in all patients presenting with post-traumatic, soft-tissue injuries when primary coverage is not possible.

The establishment rate of a sheep nematode: Revisiting classics using a meta-analysis of 87 experiments

Strongyle nematode establishment rate in their host is a highly variable life history trait, which makes it difficult to estimate. A meta-analysis was applied to the nematode Teladorsagia circumcincta of sheep in order to acquire a general framework of the factors modulating this life trait. A linear model was built with individual data on 540 infected lambs extracted from 13 articles. Lambs breed and age, time lag between last infection and the interaction between infection mode, infective dose and the number of repeated infective doses were significantly related with the establishment rate. The influence of infection mode on nematode establishment rate was also evaluated by comparing nematode establishment rate distributions within lamb populations infected under different conditions. Natural and repeated experimental infections lead to similar distribution of establishment rate. Conversely, these infection conditions resulted in different parasite establishment rates in average (12.7 and 23.4%, respectively). Three hypotheses are discussed to explain this result: immune protective response, host avoidance behaviour and parasite virulence.

Estimation of abomasum strongyle nematode infections in sheep at necropsy: Tentative proposals for a simplified technique

Several necropsy techniques are available for estimating the abundance of gastro-intestinal nematodes in abomasum of ruminants. Standardization of techniques is needed to allow accurate comparisons between laboratories. Here we propose a standardized technique for estimating the abundance of worms. We intend to compare the worms' number estimations in lambs and ewes based on contents and washings, to determine the uniformity of worm counts in aliquots, and to estimate the total worm number from washings. The digesta (or "contents") and the washings of the abomasum are treated separately. The worms of each subsample are diluted with water and the total number of worms is estimated on a small volume (aliquots) of these subsamples. The use of aliquots assumes that the worms are uniformly distributed in the whole volume of each subsample. We first confirmed that the use of aliquots is appropriate in most cases. We then show that the use of the washings alone allows a faster and a suitable estimation of the total worm burden for all strongyle species of the abomasum in both ewes and lambs. The evaluation of our necropsy procedure is a first step to a standardized technique which should be improved by validation in other laboratories.

The early drug selection of nematodes to anthelmintics: stochastic transmission and population in refuge

We have developed an individual-based model to reflect the complexity of the early phase of drug resistance selection in a nematode/sheep model. The infection process consists of the stochastic ingestion of infective larvae spatially aggregated in clumps. Each clump corresponds to infective larvae, which are the offspring of the mature nematodes from a given sheep. We studied the dynamics of the parasitic population and the frequency of the recessive resistance alleles during selection by anthelmintic treatments. The interaction between genetic and demographic processes illustrated the trade-off between the control of the infection and the delay of resistance selection. We confirmed the importance of the number of treatments and their timing. The same treatment frequency may result in different outcomes on resistance selection in relation to the size of the refuge (infective larvae on pasture). Treatment applied during the summer (when the mortality of infective larvae on pasture was high), may lead to a rapid selection of drug resistance and a lack of control of sheep and pasture contamination. We showed that higher stocking rates were also a force in promoting the resistance allele selection.

Estimation of methicillin-resistant Staphylococcus aureus transmission by considering colonization pressure at the time of hospital admission

Our objective was to evaluate the accuracy of a methicillin-resistant Staphylococcus aureus (MRSA) rate using the imported MRSA reservoir identified at the time of hospital admission. Two indicators were used: the number of imported MRSA patient-days/total number of patient-days [representing colonization pressure (CP) at the time of admission] and the incidence of hospital-acquired MRSA isolated from clinical samples expressed as density/100 patient-days for carriers identified at the time of admission [representing the incidence taking CP into account (ICP)]. The variations of these indicators were analysed and compared with two more common indicators: percentage of MRSA acquired in our hospital and the incidence of hospital-acquired MRSA isolated from clinical samples expressed as density/1000 patient-days within three four-month periods during 2002. Common indicators varied similarly, with marked decline during the third period; first-period CP was twice that of other periods (P<10(-6)) and the highest (>two-fold) ICP was seen in the summer (second) period (P<0.001) when the personnel/patient ratio was the lowest. Thus, comparison of different indicators within four-month periods underlines important differences between common and novel indicators. Despite several limitations, ICP should be helpful in the interpretation of MRSA surveillance data, particularly for estimating the extent of MRSA transmission.

[Consequences of replacing abacavir for indinavir in successful antiretroviral treatment of a patient with HIV infection]

INTRODUCTION

Simplification of combined antiretroviral therapy in HIV-infected patients is possible, but virological success can be compromised by the development or emergence of resistant viruses.

CASE

Worsening renal functioning in a patient under successful combination antiretroviral therapy resulted led to the replacement of indinavir by abacavir. Eight weeks later, his viral load rose and he developed a mutant virus resistant to all the nucleoside analogs.

DISCUSSION

Our case report illustrates the danger of streamlining combined antiretroviral therapy composed only of nucleoside analogs in patients already successfully treated with nucleoside analogs, by exposing them to the risk of the emergence of a mutant virus.

Modelling macroparasite aggregation using a nematode-sheep system: the Weibull distribution as an alternative to the Negative Binomial distribution?

Macroparasites are almost always aggregated across their host populations, hence the Negative Binomial Distribution (NBD) with its exponent parameter k is widely used for modelling, quantifying or analysing parasite distributions. However, many studies have pointed out some drawbacks in the use of the NBD, with respect to the sensitivity of k to the mean number of parasites per host or the under-representation of the heavily infected hosts in the estimate of k. In this study, we compare the fit of the NBD with 4 other widely used distributions on observed parasitic gastrointestinal nematode distributions in their sheep host populations (11 datasets). Distributions were fitted to observed data using maximum likelihood estimator and the best fits were selected using the Akaike's Information Criterion (AIC). A simulation study was also conducted in order to assess the possible bias in parameter estimations especially in the case of small sample sizes. We found that the NBD is seldom the best fit for gastrointestinal nematode distributions. The Weibull distribution was clearly more appropriate over a very wide range of degrees of aggregation, mainly because it was more flexible in fitting the heavily infected hosts. Moreover, the Weibull distribution estimates are less sensitive to sample size. Thus, when possible, we suggest to carefully check on observed data if the NBD is appropriate before conducting any further analysis on parasite distributions.

Impact of screening for MRSA carriers at hospital admission on risk-adjusted indicators according to the imported MRSA colonization pressure

We evaluated the impact of the different components of a screening programme of methicillin-resistant Staphylococcus aureus (MRSA) carriers at hospital admission on the value of two risk-adjusted rates: the proportion of imported MRSA and an indicator of the MRSA colonization pressure (ICP), and the incidence of MRSA acquired and detected in our hospital. Indicators were calculated: (1) with no screening programme; (2) with a programme limited to the intensive care unit (ICU); (3) with a programme extended to patients with risk factors for MRSA carriage hospitalized in non-ICU wards. The programme included an automatic alert. Systematic sampling of patients with risk factors hospitalized in non-ICU settings detected nearly 50% of carriers at admission. The proportion of MRSA imported into our hospital varied from 35.4% without any screening programme to 71.8% when all components of our screening programme were considered (P<10(-4)). The ICP varied from 3.1% (31/985) with the complete programme to 10.4% (31/297) without any screening programme (P<10(-6)). Screening patients with risk factors for MRSA carriage hospitalized in non-ICU wards resulted in a 51% increase of the calculated proportion of imported strains and a 58% decrease of the ICP. The two studied indicators were strongly dependent on the screening strategy for MRSA carriers implemented at admission. The screening strategy for patients admitted to non-ICU wards who have risk factors for MRSA carriage seems to be the determinant for the interpretation of certain risk-adjusted indicators of MRSA cross-transmission. Comparisons of these indicators must consider the setting in which the screening programmes are implemented.

Cardiovascular disease in patients with diabetes: clinical considerations

Cardiovascular disease is the major cause of morbidity and mortality in patients with diabetes. Diabetic individuals have a 200% to 400% greater risk for vascular disease than nondiabetics, with a disproportionately greater burden of disease complications in non-white minorities. Although the atherosclerotic plaques in the two groups are similar, diabetics have more severe and more diffuse disease than nondiabetics. Recent advances in the treatment of coronary disease have improved survival for diabetics and nondiabetics, but diabetics still have double the case fatality rate as nondiabetics, and diabetic women have particularly poor outcomes. Diabetic individuals also have an increased frequency of silent ischemia, systolic and diastolic left ventricular dysfunction, and cardiac autonomic neuropathy. The high frequency of modifiable risk factors provides great opportunities for prevention, the cornerstones of therapy being glycemic control, aggressive risk factor modification, and ongoing patient surveillance and monitoring to facilitate early disease detection and prompt intervention. In patients with coronary disease who require revascularization, both mechanical coronary interventions and bypass surgery are effective therapies. Patients with multivessel coronary disease have better results following bypass surgery with arterial grafts than following coronary interventions. However, diabetic patients are at increased risk for poor long-term outcome following either revascularization modality, with high rates of restenosis following mechanical interventions and the development of atherosclerosis in conduits following bypass surgery.

Spectroscopic studies on angiotensin I-converting enzyme

We used near and far UV spectrophotometry for the re-evaluation of the molar extinction coefficient at 280 nm (epsilon 280) of pulmonary angiotensin-converting enzyme (ACE), for the determination of its tryptophan and tyrosine contents and to follow-up guanidine denaturation. ACE purity was assessed by both SDS-PAGE and capillary electrophoresis performed in denaturing conditions. The maxima of the near UV spectrum of purified ACE, dissolved in phosphate buffer pH 6.5, was at 279 nm; with an estimated M(r) of 160 kD, epsilon 280 of native ACE was 1.5 +/- 0.05 x 10(5) (mol/l)-1 x cm-1. Denaturation of ACE by 6 mol/l guanidine hydrochloride produced a hypochromic effect of 23% at 280 nm and led to a blue shift of 3.5 nm. In guanidine solution, absorbance measurements at 288 and 280 nm predicted a ratio of 1 between tyrosine and tryptophan, whereas it was 1.8 with the measure of the amplitude of the spectral bands at 283 and 292 nm of the second derivative of the near UV spectrum. Unfolding of the peptide chain in 6 mol/l guanidine was also well characterized by the second derivative of the far UV spectrum, in parallel with the complete loss of enzymatic activity although the protein remained whole as judged on SDS-PAGE. We also re-evaluated ACE zinc content by atomic absorption spectroscopy and demonstrated that ACE molecule obviously contains two zinc atoms.

[Vascular effects of adenosine-triphosphate]

This study assessed the effects of adenosine triphosphate (ATP) on systemic vascular resistances during the hypothermic cardiopulmonary bypass phase of cardiac surgery. Twenty patients scheduled for cardiac surgery were randomly divided into an ATP group (n = 10), and a placebo group (n = 10). Anaesthesia was similar for all the patients (diazepam, fentanyl and pancuronium). During the heart arrest phase, and as soon as the arterial pressure, the level in the venous return reservoir, and the pump flow rate had all been in steady state for 5 min, ATP or placebo was injected into the venous line of the oxygenator. Injection speed was doubled every three minutes, twice. The following ATP doses were administered: 0.012, 0.025 and 0.05 mg.kg-1.min-1. The level in the venous return reservoir was kept constant. Mean arterial pressure (MAP) and pump flow rate (DP) were assessed every half minute. Systemic vascular resistances were calculated with the relationship MAP/DP. Changes in vascular capacitance were directly proportional to changes in DP as the heart had been excluded, and all the blood returned to the pump, the blood volume being kept constant. MAP and DP remained unchanged in the placebo group. In the opposite ATP induced a dose-related systemic vasodilation: MAP decreased from 82.8 +/- 12.5 mmHg (control) to 66.0 +/- 14.8 mmHg, 59.8 +/- 10.6 mmHg, and 49.0 +/- 4.7 mmHg with 0.012, 0.025 and 0.05 mg.kg-1.min-1 ATP respectively. The MAP returned to preinfusion control levels when the ATP infusion was discontinued (90.0 +/- 17.8 mmHg). The DP, and therefore venous return, did not change, neither during ATP infusion, nor after its discontinuation.(ABSTRACT TRUNCATED AT 250 WORDS)