Ancient Sheep Genomes Reveal Four Millennia of North European Short-Tailed Sheep in the Baltic Sea Region.

Sheep are among the earliest domesticated livestock species, with a wide variety of breeds present today. However, it remains unclear how far back this diversity goes, with formal documentation only dating back a few centuries. North European short-tailed (NEST) breeds are often assumed to be among the oldest domestic sheep populations, even thought to represent relicts of the earliest sheep expansions during the Neolithic period reaching Scandinavia <6,000 years ago. This study sequenced the genomes (up to 11.6X) of five sheep remains from the Baltic islands of Gotland and Åland, dating from the Late Neolithic (∼4,100 cal BP) to historical times (∼1,600 CE). Our findings indicate that these ancient sheep largely possessed the genetic characteristics of modern NEST breeds, suggesting a substantial degree of long-term continuity of this sheep type in the Baltic Sea region. Despite the wide temporal spread, population genetic analyses show high levels of affinity between the ancient genomes and they also exhibit relatively high genetic diversity when compared to modern NEST breeds, implying a loss of diversity in most breeds during the last centuries associated with breed formation and recent bottlenecks. Our results shed light on the development of breeds in Northern Europe specifically as well as the development of genetic diversity in sheep breeds, and their expansion from the domestication center in general.

Burns management in the military and humanitarian setting.

Burns are an unpredictable element of the modern battlespace and humanitarian operations. Most military burns are small and may not be a significant challenge for deployed healthcare assets but usually render the individual combat ineffective until healed. However, larger burns represent a more significant challenge because of the demand for fluid resuscitation therapy, early surgical intervention and regular wound management that can rapidly deplete surgical capabilities. Beyond the initial injury, longer-term consequences, such as psychological morbidity and loss of functional independence, are rarely considered as part of an ongoing care plan. Globally, most of the morbidity and mortality associated with burns are seen in less economically developed countries and are frequently associated with conflicts and natural disasters, but with simple interventions and resources, outcomes in these environments can be markedly improved. Prehospital providers should be confident to manage the initial assessment of a burn, including triaging for evacuation and packaging for safe transfer. This article provides an overview for prehospital providers on the management of thermal burns in military and humanitarian settings, with additional considerations for the management of chemical and electrical injuries.

St Andrew's COVID-19 surgery safety (StACS) study: The Burns Centre experience.

BACKGROUND: The COVID-19 pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has the potential to significantly impact burns patients both directly through infective complications of an immunocompromised cohort, and indirectly through disruption of care pathways and resource limitations. The pandemic presents new challenges that must be overcome to maintain patient safety; in particular, the potential increased risks of surgical intervention, anaesthesia and ventilation. This study comprehensively reviews the measures implemented to adapt referral pathways and mitigate the risk posed by COVID-19 during the height of the pandemic, within a large Burns Centre. METHODS: A prospective cohort study was designed to assess patients treated at the Burns Centre during the UK COVID-19 pandemic peak (April-May 2020), following implementation of new safety measures. All patients were analysed for 30-day mortality. In addition, a prospective controlled cohort study was undertaken on all inpatients and a random sample of outpatients with telephone follow-up at 30 days. These patients were divided into three groups (operative inpatients, non-operative inpatients, outpatients). COVID-19 related data collected included test results, contact with proven cases, isolation status and symptoms. The implemented departmental service COVID-19 safety adaptations are described. RESULTS: Of 323 patients treated at the Burns Centre during the study period, no 30-day COVID-19 related deaths occurred (0/323). Of the 80 patients analysed in the prospective controlled cohort section of the study, 51 underwent COVID-19 testing, 3.9% (2/51) were positive. Both cases were in the operative group, however in comparison to the non-operative and outpatient groups, there was no significant increase in COVID-19 incidence in operative patients. CONCLUSIONS: We found no COVID-19 related mortality during the study period. With appropriate precautions, burns patients were not exposed to an increased COVID-19 risk. Similarly, burns patients undergoing operative management were not at a significantly increased risk of contracting COVID-19 in comparison to non-operative groups.

Deliberating performance targets workshop: Potential paths for emerging PM2.5 and O3 air sensor progress.

The United States Environmental Protection Agency held an international two-day workshop in June 2018 to deliberate possible performance targets for non-regulatory fine particulate matter (PM2.5) and ozone (O3) air sensors. The need for a workshop arose from the lack of any market-wide manufacturer requirement for Ozone documented sensor performance evaluations, the lack of any independent third party or government-based sensor performance certification program, and uncertainty among all users as to the general usability of air sensor data. A multi-sector subject matter expert panel was assembled to facilitate an open discussion on these issues with multiple stakeholders. This summary provides an overview of the workshop purpose, key findings from the deliberations, and considerations for future actions specific to sensors. Important findings concerning PM2.5 and O3 sensors included the lack of consistent performance indicators and statistical metrics as well as highly variable data quality requirements depending on the intended use. While the workshop did not attempt to yield consensus on any topic, a key message was that a number of possible future actions would be beneficial to all stakeholders regarding sensor technologies. These included documentation of best practices, sharing quality assurance results along with sensor data, and the development of a common performance target lexicon, performance targets, and test protocols.

A review of the evidence for threshold of burn injury.

INTRODUCTION: Burn injury is common and depth is one measure of severity. Although the depth of burn injury is determined by many factors, the relationship between the temperature of the injurious agent and exposure duration, known as the time-temperature relationship, is widely accepted as one of the cornerstones of burn research. Moritz and Henriques first proposed this relationship in 1947 and their seminal work has been cited extensively. However, over the years, readers have misinterpreted their findings and incorporated misleading information about the time-temperature relationship into a wide range of industrial standards, burn prevention literature and medicolegal opinion. AIM: The purpose of this paper is to present a critical review of the evidence that relates temperature and time to cell death and the depth of burn injury. These concepts are used by researchers, burn prevention strategists, burn care teams and child protection professionals involved in ascertaining how the mechanism of burning relates to the injury pattern and whether the injury is consistent with the history. REVIEW METHODS: This review explores the robustness of the currently available evidence. The paper summarises the research from burn damage experimental work as well as bioheat transfer models and discusses the merits and limitations of these approaches. REVIEW FINDINGS: There is broad agreement between in vitro and in vivo studies for superficial burns. There is clear evidence that the perception of pain in adult human skin occurs just above 43°C. When the basal layer of the epidermis reaches 44°C, burn injury occurs. For superficial dermal burns, the rate of tissue damage increases logarithmically with a linear increase in temperature. Beyond 70°C, rate of damage is so rapid that interpretation can be difficult. Depth of injury is also influenced by skin thickness, blood flow and cooling after injury. There is less clinical evidence for a time-temperature relationship for deep or subdermal burns. Bioheat transfer models are useful in research and becoming increasingly sophisticated but currently have limited practical use. Time-temperature relationships have not been established for burns in children's skin, although standards for domestic hot water suggest that the maximum temperature should be revised downward by 3-4°C to provide adequate burn protection for children. CONCLUSION: Time-temperature relationships established for pain and superficial dermal burns in adult human skin have an extensive experimental modeling basis and reasonable clinical validation. However, time-temperature relationships for subdermal burns, full thickness burns and burn injury in children have limited clinical validation, being extrapolated from other data, and should be used with caution, particularly if presented during expert evidence.

Optimising ballistic facial coverage from military fragmenting munitions: a consensus statement.

VIRTUS is the first United Kingdom (UK) military personal armour system to provide components that are capable of protecting the whole face from low velocity ballistic projectiles. Protection is modular, using a helmet worn with ballistic eyewear, a visor, and a mandibular guard. When all four components are worn together the face is completely covered, but the heat, discomfort, and weight may not be optimal in all types of combat. We organized a Delphi consensus group analysis with 29 military consultant surgeons from the UK, United States, Canada, Australia, and New Zealand to identify a potential hierarchy of functional facial units in order of importance that require protection. We identified the causes of those facial injuries that are hardest to reconstruct, and the most effective combinations of facial protection. Protection is required from both penetrating projectiles and burns. There was strong consensus that blunt injury to the facial skeleton was currently not a military priority. Functional units that should be prioritised are eyes and eyelids, followed consecutively by the nose, lips, and ears. Twenty-nine respondents felt that the visor was more important than the mandibular guard if only one piece was to be worn. Essential cover of the brain and eyes is achieved from all directions using a combination of helmet and visor. Nasal cover currently requires the mandibular guard unless the visor can be modified to cover it as well. Any such prototype would need extensive ergonomics and assessment of integration, as any changes would have to be acceptable to the people who wear them in the long term.

Middle cranial fossa sphenoidal region dural arteriovenous fistulas: anatomic and treatment considerations.

BACKGROUND AND PURPOSE: DAVFs rarely involve the sphenoid wings and middle cranial fossa. We characterize the angiographic findings, treatment, and outcome of DAVFs within the sphenoid wings. MATERIALS AND METHODS: We reviewed the clinical and radiologic data of 11 patients with DAVFs within the sphenoid wing that were treated with an endovascular or with a combined endovascular and surgical approach. RESULTS: Nine patients presented with ocular symptoms and 1 patient had a temporal parenchymal hematoma. Angiograms showed that 5 DAVFs were located on the lesser wing of sphenoid bone, whereas the other 6 were on the greater wing of the sphenoid bone. Multiple branches of the ICA and ECA supplied the lesions in 7 patients. Four patients had cortical venous reflux and 7 patients had varices. Eight patients were treated with transarterial embolization using liquid embolic agents, while 3 patients were treated with transvenous embolization with coils or in combination with Onyx. Surgical disconnection of the cortical veins was performed in 2 patients with incompletely occluded DAVFs. Anatomic cure was achieved in all patients. Eight patients had angiographic and clinical follow-up and none had recurrence of their lesions. CONCLUSIONS: DAVFs may occur within the dura of the sphenoid wings and may often have a presentation similar to cavernous sinus DAVFs, but because of potential associations with the cerebral venous system, may pose a risk for intracranial hemorrhage. Curative embolization through a transarterial or transvenous approach is the primary therapeutic strategy for these lesions. In incompletely embolized patients, exclusion of any refluxing cortical veins is necessary.

Surgical strategies for aneurysms deemed unclippable and uncoilable.

Although most cerebral aneurysms can nowadays be successfully treated either by standard clipping or sole coiling, a subset of aneurysms may not be amenable to standard clipping or coiling and require alternative treatment options. Surgical options, other than clipping and/or endovascular options other than sole coiling, may be the optimal treatment plan for some complex aneurysms. Surgical strategies for such complex aneurysms include parent artery occlusion, revascularization procedures and flow redirection. In this article, we review which factors are predictive of failure of conventional aneurysm treatment options; summarize key information needed to orient treatment decision; and discuss surgical options for unclippable and uncoilable aneurysms.

Patient satisfaction following nipple-areolar complex reconstruction and tattooing.

BACKGROUND: Nipple-areolar complex (NAC) reconstruction and tattooing complete and compliment reconstruction of the breast mound. Patient satisfaction with NAC reconstruction and tattoo, independent from breast mound reconstruction is evaluated in this study. METHODS: Patients who underwent nipple tattooing between January 2001 and June 2008 were sent a postal questionnaire retrospectively. Questions included those regarding reconstruction type, patient satisfaction with NAC reconstruction and tattoo outcome, and complications. RESULTS: 110 patients with completed questionnaires were included from the 172 patients who were invited. Median follow up time was 38.5 months (1-86). Eighty eight percent reported overall satisfaction with their NAC reconstruction. Seventy percent of patients were satisfied with their nipple tattoos. All procedures were done in a day case setting and eighty-nine patients reported no postoperative complications. The commonest causes for disappointment were lack of projection of the NAC reconstruction and fading of tattoos. Ninety-six percent of women stated that NAC reconstruction and tattooing were important to them, and 93% of the patients would undergo the procedures again. CONCLUSION: We believe that NAC reconstruction is an important and integral part of breast reconstruction. This study should inform surgeons and patients regarding outcome, possible complications and the potential need and timing of further tattooing.

Symptomatic Rathke's cleft cysts: a report of 24 cases.

We review the clinical, hormonal and imaging features of 24 consecutive patients with symptomatic Rathke's cleft cysts (RCCs), and assess the long-term effectiveness and complications of transsphenoidal cyst removal. Out of 250 consecutive patients, 24 (10%) underwent endonasal transsphenoidal surgery for RCC; 19 (79%) were women. Symptoms at presentation included headaches (83%), hyperprolactinemia (38%), central hypothyroidism (21%), galactorrhea (13%), diabetes insipidus (13%), IGF-1 deficiency (13%), central adrenal insufficiency (8%) and visual loss (8%). In total, 37% of women had irregular menses and 60% of men sexual dysfunction and hypogonadism. Two girls presented with precocious puberty. Cyst size varied from 7 to 25 mm. Fifteen (60%) had a suprasellar component. Initial and 3-month post-operative imaging revealed complete cyst resection in 23 of 24 patients. Headaches resolved in 65% of subjects and visual loss resolved in both patients who presented with this symptom. Of those presenting with endocrinopathy, 56% had improvement of at least one anterior pituitary axis; two subjects (8%), both with suprasellar RCC, developed a new hormone deficiency post-operatively and two sujects young girls, (8%) had RCC recurrence, one at 36 months after surgery, requiring a second operation, and the other had a small asymptomatic recurrence 6 months after surgery. In conclusion, RCC accounts for 10 % of surgically treated sellar and suprasellar masses. Headache, hyperprolactinemia, menstrual irregularities and sexual dysfunction are common presenting symptoms. Simple cyst removal via a transsphenoidal approach offers a safe and effective treatment. Cyst recurrence may be more common in children.

The discovery of viral hepatitis: a military perspective.

Viral hepatitis is one of the most common infectious diseases and over the years the jaundice associated with it has been known by many names. Several viruses are now known to cause hepatitis in humans, but sixty years ago, these viruses were unknown. In the years before and during the Second World War, there emerged a significant understanding of the clinical and epidemiological nature of the disease due to the dedicated efforts of doctors and scientists around the world. By the end of the war years, the discrete entities of Hepatitis A and B had been identified and preventative measures were proving to be effective. However, the bane of viral hepatitis was far from being resolved.

Assessment of cerebral blood flow by means of blood-flow-volume measurement in the internal carotid artery: comparative study with a 133xenon clearance technique.

BACKGROUND AND PURPOSE: We sought to evaluate a new, angle-independent ultrasonic device for assessment of blood flow volume (BFV) in the internal carotid artery (ICA). METHODS: Nineteen patients and 4 healthy volunteers were enrolled in a comparative study conducted in the Care Unit of the Division of Neurosurgery at UCLA Medical Center. All patients had been admitted because of severe brain injury: 15 patients with severe head trauma (Glasgow Coma Scale score< or =8) and 4 patients with subarachnoid hemorrhage due to aneurysm rupture. In all patients and subjects, cerebral blood flow (CBF) values obtained with the 133xenon-clearance technique were compared with BFV measurements in the ipsilateral ICA. RESULTS: Hemispheric CBF values showed a close and linear correlation with BFV measurements (r=0.76, P<0.0001). Global CBF values showed a higher correlation with the total BFV value obtained from both ICAs (r=0.84, P<0.0001). With 37 mL x min(-1) x 100 g(-1) as a cutoff value for the ischemic range, a BFV value of 220 mL/min would yield a positive predictive value of 91.7% and a negative predictive value of 82.6% (sensitivity 73.3%, specificity 95%). Conversely, BFV sensitivity and specificity were 60% and 96%, respectively, for the hyperemic range defined by a CBF value >55 mL x min(-1) x 100 g(-1) (positive predictive value of 85.7% and negative prediction value of 85.7%). CONCLUSIONS: BFV measurements with this new technology proved to accurately correlate with CBF values evaluated by the 133xenon-clearance technique. These results support the implementation of this technique for bedside assessment of cerebral hemodynamics in critically ill neurosurgical patients.

Acute seizures after intracerebral hemorrhage: a factor in progressive midline shift and outcome.

OBJECTIVE: To determine whether early seizures that occur frequently after intracerebral hemorrhage (ICH) lead to increased brain edema as manifested by increased midline shift. METHODS: A total of 109 patients with ischemic stroke (n = 46) and intraparenchymal hemorrhage (n = 63) prospectively underwent continuous EEG monitoring after admission. The incidence, timing, and factors associated with seizures were defined. Serial CT brain imaging was conducted at admission, 24 hours, and 48 to 72 hours after hemorrhage and assessed for hemorrhage volume and midline shift. Outcome at time of discharge was assessed using the Glasgow Outcome Scale score. RESULTS: Electrographic seizures occurred in 18 of 63 (28%) patients with ICH, compared with 3 of 46 (6%) patients with ischemic stroke (OR = 5.7, 95% CI 1.4 to 26.5, p < 0.004) during the initial 72 hours after admission. Seizures were most often focal with secondary generalization. Seizures were more common in lobar hemorrhages but occurred in 21% of subcortical hemorrhages. Posthemorrhagic seizures were associated with neurologic worsening on the NIH Stroke Scale (14.8 vs 18.6, p < 0.05) and with an increase in midline shift (+ 2.7 mm vs -2.4 mm, p < 0.03). There was a trend toward increased poor outcome (p < 0.06) in patients with posthemorrhagic seizures. On multivariate analysis, age and initial NIH Stroke Scale score were independent predictors of outcome. CONCLUSION: Seizures occur commonly after ICH and may be nonconvulsive. Seizures are independently associated with increased midline shift after intraparenchymal hemorrhage.

Delayed increase in extracellular glycerol with post-traumatic electrographic epileptic activity: support for the theory that seizures induce secondary injury.

Early post-traumatic seizures occur commonly and may have adverse clinical consequences. In order to determine the significance of post-traumatic seizures, we performed a prospective assessment of the consequences of epileptic activity by assessing the change in extracellular glycerol levels. Glycerol is a marker of cellular membrane breakdown. Thirteen patients underwent combined electroencephalography (EEG) and cerebral microdialysis monitoring. Two patients had seizures on EEG with associated delayed elevations of glycerol associated with the seizure activity. Higher mean levels of glycerol were present in those patients with seizures compared to those without seizures (p < 0.001). Preliminary evidence suggests that post-traumatic seizures lead to additional membrane injury as reflected by elevated extracellular glycerol levels.

Metabolic suppressive therapy as a treatment for intracranial hypertension--why it works and when it fails.

Thirty years after its first description metabolic suppressive therapy is still controversial in patients with intractable intracranial hypertension. In this study high dose propofol was used to induce metabolic suppression. The effects on intracranial pressure (ICP) and the cerebral metabolic rates for oxygen and glucose (CMRO2 and CMRGlc) are reported. A total of 28 studies were performed on 14 head injured patients. A Xenon133 cerebral blood flow (CBF) and a CO2-reactivity (CO2R) test were performed prior to induction of metabolic suppression. The following parameters were continuously monitored: EEG, etCO2, SjvO2, ICP, MAP and bilateral MCA flow velocity (VMCA). PCO2 was obtained before and during propofol-induced EEG burst-suppression in arterial and jugular-venous blood. CMRO2, CMRGlc and Metabolic Ratio (MR = CMRO2/CMRGlc) were calculated. MR < 0.6 was defined as relative hyperglycolysis. ICP decreased by 24.1 +/- 29.0% during burst-suppression. Arterial, jugular-venous and etCO2 also decreased. Multiple regression analysis revealed that CO2 was the strongest predictor for ICP. Lower baseline ICP and normal CO2 reactivity were predictors for normal metabolic suppression reactivity. In studies with normal metabolic ratio, ICP reduction was associated with a reduction in CMRO2. In studies with hyperglycolysis, ICP reduction was poor but CMRGlc decreased significantly. In conclusion, intact CO2R, normal or only moderately elevated ICP and normal MR are predictive of ICP reduction with high dose propofol after head injury.

Is CPP therapy beneficial for all patients with high ICP?

Induced blood pressure elevation has become a popular treatment for intracranial hypertension. However, there remains a concern that in some patients blood pressure elevation will further elevate ICP. This study was conducted to test the hypothesis that increasing MAP decreases ICP. A total of 47 studies were performed on 23 intubated patients with head injury. MAP and SjvO2 were continuously monitored. MAP was raised significantly by 13.8 (5.9) mmHg (t-test; p < 0.0001) using phenylephrine infusion. The percent change ICP per mmHg increase in MAP (% delta ICP/mm Hg MAP) was calculated. Pearson correlation coefficient, t-test and logistic regression analysis were used for statistical evaluation. Increasing MAP resulted in a decrease in ICP in 38.3% and in an increase in ICP in 61.7% out of 47 studies. The following characteristics were seen in patients in whom a decrease in ICP was associated with an increase in MAP: High GCS (r = -0.61; p = 0.004) and low SjvO2 ((2 = 4.89; p = 0.027). In patients with lower GCS and high SjvO2 an increase in MAP resulted in an increase in ICP. We concluded that in the majority of studies increasing MAP was followed by an increase in ICP. CPP therapy has a selective indication in patients with high GCS, low SjvO2 and increased ICP.