Oxidized organic molecules in the tropical free troposphere over Amazonia.

New particle formation (NPF) in the tropical free troposphere (FT) is a globally important source of cloud condensation nuclei, affecting cloud properties and climate. Oxidized organic molecules (OOMs) produced from biogenic volatile organic compounds are believed to contribute to aerosol formation in the tropical FT, but without direct chemical observations. We performed in situ molecular-level OOMs measurements at the Bolivian station Chacaltaya at 5240 m above sea level, on the western edge of Amazonia. For the first time, we demonstrate the presence of OOMs, mainly with 4-5 carbon atoms, in both gas-phase and particle-phase (in terms of mass contribution) measurements in tropical FT air from Amazonia. These observations, combined with air mass history analyses, indicate that the observed OOMs are linked to isoprene emitted from the rainforests hundreds of kilometers away. Based on particle-phase measurements, we find that these compounds can contribute to NPF, at least the growth of newly formed nanoparticles, in the tropical FT on a continental scale. Thus, our study is a fundamental and significant step in understanding the aerosol formation process in the tropical FT.

Silent sinus syndrome: potentially misleading features that should be recognized.

OBJECTIVE: Silent sinus syndrome (SSS) usually manifests clinically as hypoglobus and enophthalmos. Patients may experience different symptoms and may present to an assortment of specialties and delay diagnosis and management. The objective of this article was to describe the different and sometimes misleading signs and symptoms of SSS to improve the level of suspicion and reduce time to diagnosis. METHODS: A retrospective consecutive audit of the records of all patients diagnosed with SSS between 2015 and 2019 in the Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust. Demographic and clinical data including presentation, diagnosis, and symptoms were obtained from the patients' medical files. RESULTS: Ten patients were included; mean age was 42.5 ± 11.5 years (range, 16-56 years). Four patients were initially referred to an ophthalmologist with globe asymmetry, diplopia, eyelid asymmetry, or retraction. Three patients were initially referred to an ear, nose, and throat specialist with facial asymmetry or infraorbital paraesthesia. Two patients were referred from the maxillofacial department with an incidental finding, and the last patient was seen initially by the neurology team with headaches. CONCLUSION: SSS has a variable presentation. Patients may have common or misleading signs. Patients may attend different clinics and subspecialties, and physicians should be aware of the broad range of presenting signs in this condition to prevent delay in diagnosis and further morbidity.

Ankle fractures: Getting it right first time.

INTRODUCTION: Ankle fractures are common injuries presenting to trauma departments and ankle open reduction and internal fixation (ORIF2) is one of the first procedures targeted in early orthopaedic training. Failure to address the fracture pattern with the appropriate surgical technique and hardware may lead to early failure, resulting in revision procedures or premature degenerative change. Patients undergoing revision ORIF are known to be at much greater risk of complications and many of these secondary procedures may be preventable. METHOD: A retrospective analysis of all patients attending our unit for ankle ORIF over a two year period was undertaken. Patients were identified from our Bluespier database and a review of x-rays was undertaken. All patients undergoing re-operation within eight weeks of the primary procedure were studied. The cause of primary failure was established and potential contributing patient and surgical factors were recorded. RESULTS: 236 patients undergoing ankle ORIF were identified. 13 patients (5.5%) returned to theatre for a secondary procedure within eight weeks. Within this group, seven (54%) patients returned for treatment of a neglected or under treated syndesmotic injury, three (23%) for complete failure of fixation, two (15%) with wound problems and one (8%) for medial malleolus mal-reduction. Of the patient group, five (39%) were known type 2 diabetics. Consultants performed two (15%) procedures, supervised registrars five (39%) and unsupervised registrars six (46%) operations. CONCLUSION: Errors are being made at all levels of training in applying basic principles such as restoring fibula length and screening the syndesmosis intra-operatively. Appropriate placement and selection of hardware is not always being deployed in osteopenic bone resulting in premature failure of fixation and fracture patterns are not being fully appreciated. Patients are undergoing preventable secondary procedures in the operative treatment of ankle fractures.

Assessment of accuracy of marker ball placement in pre-operative templating for total hip arthroplasty.

We report the accuracy of positioning of the calibration ball in the process of pre-operative templating for total hip arthroplasty (THA). The ball should be placed in the coronal plane of the hip to provide suitable accuracy. We reviewed 112 post-operative THA radiographs where a calibration ball had been placed. We templated the femoral head size of the implant after calibrating the templating system from the ball. The calibrated femoral head diameter was compared to the known prosthetic head size. A percentage error was calculated. Overall, incorrect placement of the calibration ball resulted in a mean percentage error in templating of 6.8% (median 5.7%; range 0-26%). Such error carries implications with the templating process and may result in incorrect component sizes, leg lengths and offset.

Outcomes of functional weight-bearing rehabilitation of Achilles tendon ruptures.

The introduction of functional rehabilitation for patients with Achilles tendon rupture has dramatically changed treatment programs for this condition. The authors introduced a functional weight-bearing protocol for patients with an acute Achilles tendon rupture treated operatively and nonoperatively in 2002. They hypothesized that no significant differences would exist in the rerupture rates and functional outcomes between the groups. Between 2002 and 2008, the authors collected data on 80 consecutive patients treated with a weight-bearing functional orthosis for complete Achilles tendon rupture. Following evidence-based counseling, 51 patients chose nonoperative treatment and 29 chose operative treatment. Outcome measures included rerupture rates, other complications, and functional scoring. The nonoperative group was a decade older (median age, 47 years [range, 27-80 years]) than the operative group (median age, 37 years [range, 24-55 years]). Rerupture was noted in 2 (4%) patients in the nonoperative treatment group and 1 (3%) patient in the operative group. Two (7%) patients in the operative group developed superficial wound infections and reported no nerve injuries. Median Achilles Tendon Total Rupture Score was 82 points in the nonoperative group and 94 in the operative group. Median Victorian Institute of Sports Assessment-Achilles tendinopathy questionnaire scores were 60 and 91 for the nonoperative and operative groups, respectively. Both groups had low rerupture rates. Functional scores, using the newly validated Achilles Tendon Total Rupture Score, were lower in the nonoperative group.

A novel mutation in the steroidogenic acute regulatory protein gene promoter leading to reduced promoter activity.

We have identified a novel cytosine/thymidine polymorphism of the human steroidogenic acute regulatory (StAR) gene promoter located 3 bp downstream of the steroidogenic factor-1 (SF-1)-binding site and 9 bp upstream of the TATA box (ATTTAAG). Carriers of this mutation have a high prevalence of primary aldosteronism. In transfection experiments, basal StAR promoter activity was unaltered by the mutation in murine Y-1 cells and human H295R cells. In Y-1 cells, forskolin (25 microM, 6 h) significantly increased wild-type promoter activity to 230+/-33% (P<0.05, n=4). In contrast, forskolin increased mutated promoter activity only to 150+/-27%, with a significant 35% reduction compared to wild type (P<0.05, n=3). In H295R cells, angiotensin II (AngII; 10 nM) increased wild-type StAR promoter activity to 265+/-22% (P<0.01, n=3), while mutated StAR promoter activity in response to AngII only reached 180+/-29% of controls (P< 0.01, n=3). Gel mobility shift assays show the formation of two additional complexes with the mutated promoter: one with the transcription repressor DAX-1 and another with a yet unidentified factor, which strongly binds the SF-1 response element. Thus, this novel mutation in the human StAR promoter is critically involved in the regulation of StAR gene expression and is associated with reduced promoter activity, a finding relevant for adrenal steroid response to physiological stimulators.

Laparoscopic surgery for fistulas that complicate diverticular disease.

BACKGROUND: Diverticular disease is complicated by colovesical and colovaginal fistulas in 4-20% of patients. Laparoscopic surgery is usually reserved for selected cases of uncomplicated disease. The aim of this study was to assess the efficacy and effectiveness of laparoscopic surgery in the treatment of those patients. METHODS: Eighteen patients, 15 with colovesical fistulas and three with colovaginal fistulas, were operated on laparoscopically. Prospectively collected data, associated with technical feasibility, short-term outcome and effectiveness, were analysed. RESULTS: Twelve sigmoidectomies, four extended left colectomies and two segmentectomies were performed. Fistulas were treated with simple dissection or mechanical division, and the bladder wall was repaired in two patients. Mean operating time was 237 min (range 165-330). There was one conversion (5.5%) and no post-operative death. Morbidity was 27.7% and included one major complication. Return of gastrointestinal function occurred 2.9 days post-operatively, and the mean hospital stay was 10 days after surgery. During the 5.1-year follow-up period there was one fistula recurrence (5.5%) and no recurrent diverticulitis. CONCLUSIONS: Laparoscopic one-stage surgery was technically feasible and safe, with low morbidity. Effectiveness appears favourable when compared with open surgery, but prospective randomized studies are necessary to support such a conclusion.