If you build it, will they come? Is test site availability a root cause of geographic disparities in COVID-19 testing?

OBJECTIVES: The purpose of this study was to examine the relationship between test site availability and testing rate within the context of social determinants of health. STUDY DESIGN: A retrospective ecological investigation was conducted using statewide COVID-19 testing data between March 2020 and December 2021. METHODS: Ordinary least squares and geographically weighted regression were used to estimate state and ZIP code level associations between testing rate and testing sites per capita, adjusting for neighbourhood-level confounders. RESULTS: The findings indicate that site availability is positively associated with the ZIP code level testing rate and that this association is amplified in communities of greater economic deprivation. In addition, economic deprivation is a key factor for consideration when examining ethnic differences in testing in medically underserved states. CONCLUSION: The study findings could be used to guide the delivery of testing facilities in resource-constrained states.

Diffusion MR imaging acquisition and analytics for microstructural delineation in pre-clinical models of TBI.

Significant progress has been made toward improving both the acquisition of clinical diffusion-weighted imaging (DWI) data and its analysis in the uninjured brain, through various techniques including a large number of model-based solutions that have been proposed to fit for multiple tissue compartments, and multiple fibers per voxel. While some of these techniques have been applied to clinical traumatic brain injury (TBI) research, the majority of these technological enhancements have yet to be fully implemented in the preclinical arena of TBI animal model-based research. In this review, we describe the requirement for preclinical, MRI-based efforts to provide systematic confirmation of the applicability of some of these models as indicators of tissue pathology within the injured brain. We review how current DWI techniques are currently being used in animal TBI models, and describe how both acquisition and analytic techniques could be extended to leverage the progress made in clinical work. Finally, we highlight remaining gaps in the preclinical pipeline from data acquisition to final analysis that currently have no real, preclinical-based correlate.

Long-term outcomes of laparoscopic large hiatus hernia repair with nonabsorbable mesh.

The use of mesh to augment suture repair of large hiatus hernias remains controversial. Repair with mesh may help reduce the recurrence rate of primary repair, but concerns about the potential for serious complications, such as mesh erosion or stricturing, continue to limit its use. We aim to evaluate the long-term outcome of primary hiatus hernia repair with lightweight polypropylene mesh (TiMesh) specifically looking at rates of clinical recurrence, dysphagia, and mesh-related complications. From a prospectively maintained database, 50 consecutive patients who underwent elective primary laparoscopic hiatal hernia repair with TiMesh between January 2005 and December 2007 were identified. Case notes and postoperative endoscopy reports were reviewed. Clinical outcomes were evaluated using a structured questionnaire, including a validated dysphagia score. Of the 50 patients identified, 36 (72%) were contactable for follow-up. At a median follow-up of 9 years, the majority of patients (97%) regarded their surgery as successful. Twelve patients (33%) reported a recurrence of their symptoms, but only 4 (11%) reported that their symptoms were as severe as prior to the surgery. There was no significant difference between pre- and postoperative dysphagia scores. Postoperative endoscopy reports were available for 32 patients at a median time point of 4 years postoperatively, none of which revealed any mesh-related complications. One patient had undergone a revision procedure for a recurrent hernia at another institution. In this series, primary repair of large hiatus hernia with nonabsorbable mesh was not associated with any adverse effects over time. Patient satisfaction with symptomatic outcome remained high in the long term.

Small-angle neutron scattering study of a dense microemulsion system formed with an ionic liquid.

Mixtures of water, octane and 1-octanol with 1-tetradecyl-3-methylimidazolium chloride (C14MIM·Cl), often referred to as a surface active ionic liquid (SAIL), form water-in-oil microemulsions that have potential application as extraction media for various metal ions. Here, we present a structural study by small-angle neutron scattering (SANS) of dense microemulsions formed by surfactant-rich mixtures of these four compounds to understand how the SAIL can be used to tune the structures and properties of the microemulsions. The SANS experiments revealed that the microemulsions formed are composed of two phases, a water-in-oil microemulsion and a bicontinuous microemulsion, which becomes the dominant phase at high surfactant concentration. In this concentration regime, the surfactant film becomes more rigid, having a higher bending modulus that results from the parallel stacking of the imidazolium ring of the SAIL. At lower surfactant concentrations, the molecular packing of the SAIL does not change with the water content of the microemulsion. The results presented here correlate well with previously observed changes in the interaction between the IL cation and metal ions (Y. Tong, L. Han and Y. Yang, Ind. Eng. Chem. Res., 2012, 51, 16438-16443), while the capacity of the microemulsion system for water remains high enough for using the system as an extraction medium.

Long-term temporal trends and estimated transmission rates for Mycobacterium bovis infection in an undisturbed high-density badger (Meles meles) population.

We describe epidemiological trends in Mycobacterium bovis infection in an undisturbed wild badger (Meles meles) population. Data were derived from the capture, clinical sampling and serological testing of 1803 badgers over 9945 capture events spanning 24 years. Incidence and prevalence increased over time, exhibiting no simple relationship with host density. Potential explanations are presented for a marked increase in the frequency of positive serological test results. Transmission rates (R0) estimated from empirical data were consistent with modelled estimates and robust to changes in test sensitivity and the spatial extent of the population at risk. The risk of a positive culture or serological test result increased with badger age, and varied seasonally. Evidence consistent with progressive disease was found in cubs. This study demonstrates the value of long-term data and the repeated application of imperfect diagnostic tests as indices of infection to reveal epidemiological trends in M. bovis infection in badgers.

Race and obesity disparities among adults living in gentrifying neighborhoods.

There is a paucity of research seeking to understand race disparities in obesity among individuals living in a gentrifying neighborhood. American Community Survey data were used to identify gentrifying neighborhoods. In a cross-sectional analysis, these data were then linked to the 2014 Medical Expenditure Panel Survey, yielding an analytic sample of 887 Black and White adults. Obesity was based on body mass index ≥ 30 kg/m2. After controlling for potential confounders, Black adults living in gentrifying neighborhoods had a higher prevalence of obesity (PR: 1.39; 95% CI: 1.03, 1.88) than White adults living in gentrifying neighborhoods. Gentrification may have no impact on reducing Black-White obesity disparities in the US.

Cinematic reflectometry using QIKR, the quite intense kinetics reflectometer.

The Quite Intense Kinetics Reflectometer (QIKR) will be a general-purpose, horizontal-sample-surface neutron reflectometer. Reflectometers measure the proportion of an incident probe beam reflected from a surface as a function of wavevector (momentum) transfer to infer the distribution and composition of matter near an interface. The unique scattering properties of neutrons make this technique especially useful in the study of soft matter, biomaterials, and materials used in energy storage. Exploiting the increased brilliance of the Spallation Neutron Source Second Target Station, QIKR will collect specular and off-specular reflectivity data faster than the best existing such machines. It will often be possible to collect complete specular reflectivity curves using a single instrument setting, enabling "cinematic" operation, wherein the user turns on the instrument and "films" the sample. Samples in time-dependent environments (e.g., temperature, electrochemical, or undergoing chemical alteration) will be observed in real time, in favorable cases with frame rates as fast as 1 Hz. Cinematic data acquisition promises to make time-dependent measurements routine, with time resolution specified during post-experiment data analysis. This capability will be deployed to observe such processes as in situ polymer diffusion, battery electrode charge-discharge cycles, hysteresis loops, and membrane protein insertion into lipid layers.

Automatic determination of crystal structure.

Several crystallographic computer programs have been organized into one large automatic program for solving crystal structures. The emphasis of this organization has been to produce a noninteractive system, that is, to have all decisions made by the computer. Input data are the raw intensity data, cell constants, space group, chemical formula, and other miscellaneous items. The output is a stereo picture of the contents in a unit cell. The program, operating in a noninteractive mode, has successfully solved compounds of unknown structure; in addition, for a test compound of completely unknown composition, this program deduced the correct structure with an average error in bond distance of 0.05 angstrom and an average error in bond angle of 7 degrees .

X-ray Scattering Studies of Aligned, Stacked Surfactant Membranes.

X-ray scattering studies were performed to understand the structure and correlations in the lamellar phases of thick, freely suspeded films of (i) the hydrated phospholipid dimyristoylphosphotidylcholine (DMPC) and (ii) the ternar system consisting of the surfactant sodium dodecyl sulfate (SDS), cosurfactant (pentanol), and water. The films were drawn in a temperature- and humidity-controlled environment, where the layers were oriented to within 0.1 degrees . In the DMPC system, this made it possible to directly observe the orientation of the P(beta') modulation and to identify phase L(beta') as three distinct phases distinguished by the direction of chain tilt with respect to the lattice. In the L(alpha) phase of the ternary system, power law behavior of the (0,0,L) structure factor arising from the algebraic decay of layer correlatios was observed in single crystals.

Critical evaluation of a novel DualMesh repair for large hiatal hernias.

BACKGROUND: The use of mesh for laparoscopic repair of large hiatal hernias may reduce recurrence rates in comparison to primary suture repair. However, there is a potential risk of mesh-related oesophageal complications due to prosthesis erosion. The aim of this study was to critically evaluate a novel mesh (DualMesh) repair of hiatal hernias with particular reference to intraluminal erosion. METHOD: Medical records of 19 patients who underwent laparoscopic hiatal hernia repair with DualMesh reinforcement of the crural closure were reviewed from a prospectively collected database. Quality of life and symptom analysis was performed using quality of life in reflux and dyspepsia (QOLRAD) questionnaires pre- and postoperatively after 6 weeks, 6 months, 1 year and 2 years. Barium studies were performed on patients pre-operatively and two years postoperatively to assess hernia recurrence. After 2 years, oesophagogastric endoscopy was performed to assess signs of erosion. RESULTS: Mean patient age was 70.5 years (range 49-85 years). Two years after hiatal hernia repair, there was significant improvement in quality-of-life scores (QOLRAD: p < 0.001). Follow-up barium studies performed at 31.3 months (range 29-40 months) after surgery showed moderate recurrent hernias (>4 cm) in 1/14 patients (7%). Endoscopies performed at 34.4 months (range 28-41 months) after surgery did not show any signs of prosthetic erosion. CONCLUSION: Laparoscopic reinforcement of primary hiatal closure with DualMesh leads to a durable repair in patients with large hiatal hernias. Long-term endoscopic follow-up did not show any signs of mesh erosion after prosthetic reinforcement of the crural repair.

Short-term symptom and quality-of-life comparison between laparoscopic Nissen and Toupet fundoplications.

Laparoscopic antireflux surgery is an established method of treatment of gastroesophageal reflux disease (GERD). This study evaluates the efficacy of Nissen versus Toupet fundoplication in alleviating the symptoms of GERD and compares the two techniques for the development of post-fundoplication symptoms and quality of life (QOL) at 12 months post-surgery. In this prospective consecutive cohort study, 94 patients presenting for laparoscopic antireflux surgery underwent either laparoscopic Nissen fundoplication (LN) (n = 51) from February 2002 to February 2004 or a laparoscopic Toupet fundoplication (LT) (n = 43) from March 2004 to March 2006, performed by a single surgeon (G. S. S.). Symptom assessment, a QOL scoring instrument, and dysphagia questionnaires were applied pre- and postoperatively. At 12 months post-surgery, patient satisfaction levels in both groups were high and similar (LT: 98%, LN: 90%; P = 0.21). The proportion of patients reporting improvement in their reflux symptoms was similar in both groups (LT: 95%, LN: 92%; P = 0.68), as were post-fundoplication symptoms (LT: 30%, LN: 37%; P = 0.52). Six patients in the Nissen group required dilatation for dysphagia compared with one in the Toupet group (LT: 2%, LN: 12%; P = 0.12). One patient in the Nissen group required conversion to Toupet for persistent dysphagia (P = 0.54). In this series, overall symptom improvement, QOL, and patient satisfaction were equivalent 12 months following laparoscopic Nissen or Toupet fundoplication. There was no difference in post-fundoplication symptoms between the two groups, although there was a trend toward a higher dilatation requirement and reoperation after Nissen fundoplication.

Bioisosteric ferrocenyl aminoquinoline-benzimidazole hybrids: Antimicrobial evaluation and mechanistic insights.

Phenyl- and bioisosteric ferrocenyl-derived aminoquinoline-benzimidazole hybrid compounds were synthesised and evaluated for their in vitro antiplasmodial activity against the chloroquine-sensitive NF54 and multi-drug resistant K1 strains of the human malaria parasite, Plasmodium falciparum. All compounds were active against the two strains, generally showing enhanced activity in the K1 strain, with resistance indices less than 1. Cytotoxicity studies using Chinese hamster ovarian cells revealed that the hybrids were relatively non-cytotoxic and demonstrated selective killing of the parasite. Based on favourable in vitro antiplasmodial and cytotoxicity data, the most active phenyl (4c) and ferrocenyl (5b) hybrids were tested in vivo against the rodent Plasmodium berghei mouse model. Both compounds caused a reduction in parasitemia relative to the control, with 5c displaying superior activity (92% reduction in parasitemia at 4 × 50 mg/kg oral doses). The most active phenyl and ferrocenyl derivatives showed inhibition of ß-haematin formation in a NP-40 detergent-mediated assay, indicating a possible contributing mechanism of antiplasmodial action. The most active ferrocenyl hybrid did not display appreciable reactive oxygen species (ROS) generation in a ROS-induced DNA cleavage gel electrophoresis study. The compounds were also screened for their in vitro activity against Mycobacterium tuberculosis. The hybrids containing a more hydrophobic substituent had enhanced activity (<32.7 µM) compared to those with a less hydrophobic substituent (>62.5 µM).

Evaluation of DualMesh for repair of large hiatus hernia in a porcine model.

BACKGROUND: Prosthetic fascial grafts are frequently used for augmentation of cruroplasty in large hiatus hernia repair to decrease the chances of recurrence. Potential complications such as intraluminal erosion may be related to the constant movement of mesh and diaphragm over the outer surface of the esophagus. This study aimed to evaluate DualMesh for repair of large hiatal defects in a porcine model. METHODS: In this study, 18 Landrace x large white x Duroc crossbred pigs underwent either primary hiatal repair or tension-free prosthetic repair using DualMesh (80 x 50 mm or 80 x 100 mm). The animals were killed at 3 or 28 weeks for macroscopic and histologic evaluation of the hiatal region and gastroesophageal junction. RESULTS: All grafts had become encapsulated at 28 weeks, and the majority had filmy adhesions only to the visceral aspect. In all models, the esophagus moved freely over the cut edge of the prosthesis. No signs of intraluminal erosion were documented. At histologic examination, significant ingrowth was noted on the porous side of the mesh, whereas no defined mesothelial layer was identified on the capsule of the nonporous side. CONCLUSION: In this animal model of large hiatus hernia repair, DualMesh showed optimal characteristics in terms of host tissue incorporation on the porous side and absence of adhesions on the visceral side of the prosthesis. The absence of adhesions and intraluminal erosion in this study may provide reassurance to surgeons using mesh at the hiatus.

Total esophagogastric dissociation in adult neurologically impaired patients with severe gastroesophageal reflux: an alternative approach.

Patients with neuromuscular impairment, such as cerebral palsy or myotonic dystrophy, often suffer from oropharyngeal neuromuscular incoordination and severe gastresophageal reflux (GER). In 1997, Bianchi proposed total esophagogastric dissociation (TEGD) as an alternative to fundoplication and gastrostomy to eliminate totally the risk of recurrence of GER in neurologically impaired children. Little information exists about the best management for adult patients with severe neurological impairment in whom recurrent GER develops after failed fundoplication. We present our experience in three adult patients with neurological impairment in whom TEGD with Roux-en-Y esophagojejunostomy and feeding gastrostomy was performed for permanent treatment of GER.

Laparoscopic paraesophageal hernia repair: quality of life outcomes in the elderly.

Paraesophageal hernias (PEH) occur when there is herniation of the stomach through a dilated hiatal aperture. These hernias occur more commonly in the elderly, who are often not offered surgery despite the failure of medical treatment to address mechanical symptoms and life-threatening complications. The aim of this study was to assess the impact of laparoscopic repair of PEH on quality of life in an elderly population. Data were collected prospectively on 35 consecutive patients aged >70 years who had laparoscopic repair of a symptomatic PEH between December 2001 and September 2005. The change in quality of life was assessed using a validated questionnaire, the Quality of Life in Reflux and Dyspepsia questionnaire (QOLRAD), and by patient interviews. Patients were assessed preoperatively, and at 6 weeks, 6 months, 12 months, 1 year, and 2 years postoperatively. Mean patient age was 77 years (range 70-85); mean American Society of Anesthesiologists class was 2.7 (range 1-3). There were 28 women and 7 men. There was one readmission for acute reherniation, which required open revision. Total complication rate was 17.1%. All complications were treated without residual disability. There was no 30-day mortality, and median hospital stay was 3 days (range 2-14). Completed questionnaires were obtained in 30 of 35 patients (85.7%). There was a significant improvement in quality of life, as measured with QOLRAD, at all postoperative time points (P < 0.001). Laparoscopic PEH repair can be performed with acceptable morbidity in symptomatic patients refractory to conservative treatment and is associated with a significant improvement in quality of life. Our data support elective repair of symptomatic PEH in the elderly, a population who may not always be referred for a surgical opinion.

The utility of FDG-PET in the preoperative staging of esophageal cancer.

Accurate staging of esophageal cancer is important when determining which patients will potentially benefit from curative surgery. The aim of this study was to evaluate the incremental effect of 2-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) when used in addition to standard staging modalities. Patients referred to two surgeons in an Australian metropolitan teaching hospital with esophageal or esophago-gastric junction malignancy between May 2002 and December 2006 were included. Patients who had undergone prereferral treatment with chemotherapy or radiotherapy were excluded. Patients undergoing resection for gastrointestinal stromal tumors or high-grade dysplasia within Barrett's esophagus were also excluded. Clinical and non-clinical data were recorded prospectively. Pretreatment staging included routine CT scan and selective endoscopic ultrasound (EUS). FDG-PET was performed in patients judged to have curable disease on CT scanning and EUS. From a total of 130 eligible patients, 76 were judged to have curable disease on the basis of CT and EUS findings. Of these 76 patients, 19 (25%) were excluded from surgery due to additional information obtained from FDG-PET. The addition of FDG-PET to routine preoperative staging resulted in the exclusion from surgery of 19 (25%) patients who prior to the introduction of FDG-PET would have undergone attempted resection. FDG-PET should be performed in all patients under consideration for esophagogastric resection in order to avoid resection in patients with disseminated disease.

Nephro-cutaneous fistula in a dog.

Nephro-cutaneous fistula, although reported in humans, has not been reported in the dog. In humans the majority of cases develop in patients with a history of previous renal surgery, renal trauma, renal tumours, or chronic urinary tract infection with abscess formation. The dog in this report developed a nephro-cutaneous fistula secondary to a traumatic induced renal abscess with formation of a draining sinus tract to the exterior of the body. The animal underwent simple nephrectomy, which resulted in complete resolution of the fistula.

Ipsilateral vascularised ulnar transposition autograft for limb-sparing surgery of the distal radius in 2 dogs with osteosarcoma.

Canine osteosarcoma is the most commonly diagnosed primary bone tumour in the dog, affecting mainly large and giant breed dogs with the predilection site being the metaphysis of long bones, specifically the distal radius, proximal humerus, distal femur and proximal tibia and fibula. Treatment options are either palliative or curative intent therapy, the latter limb amputation or limb-sparing surgery together with chemotherapy. This article describes the use of an ipsilateral vascularised ulnar transposition autograft as well as chemotherapy in 2 dogs with osteosarcoma of the distal radius. Both dogs showed minimal complications with the technique and both survived over 381 days following the surgery. Complications seen were loosening of the screws and osteomyelitis. The procedure was well tolerated with excellent limb use. This technique is indicated for use in cases with small tumour size that have not broken through the bone cortex.

Unsaturated fatty acid requirements for growth and survival of a rat mammary tumor cell line.

A cell line, the growth and survival of which is markedly affected by linoleic acid, has been established from a carcinogen-induced rat mammary tumor. The cells have been continuously passaged in 5% rat serum plus 10% fetal calf serum-supplemented medium. The rat serum component was found to be indispensalbe, for when it was omitted the growth rate rapidly declined and the cells died by 5 to 7 days. Removal of the rat serum from the growth medium also resulted in a dramatic loss of Oil Red O-positive droplets in the cells, suggesting that the lipid component of rat serum might be a major growth-promoting principle in rat serum. This is likely since the total lipid fraction, but not the delipidized protein fraction, could largely supplant requirement of the cells for rat serum. Pure linoleic acid was found to be effective in maintaining the cell growth in delipidized serum or in whole fetal calf serum-supplemented medium. Fatty acid analysis revealed a 19-fold higher amount of linoleic acid in rat serum than in fetal calf serum.

The H+/ATP stoichiometry of the (H+ +K+)-ATPase of dog gastric microsomes.

Gastric microsomal vesicles isolated from dog fundic mucosa were shown to be relatively ion tight and have a low level of proton permeability. The H+ translocase, basal ATPase and K+-activated ATPase activities of these vesicles were measured and the H+/ATP stoichiometry calculated using either the total K+-ATPase or the K+-stimulatable component (total K+-ATPase--basal ATPase). The former estimations consistently gave stoichiometric of approximately one, whereas the use of only the K+-stimulatable component gave widely differing values. Measurement of the dephosphorylation of the enzyme under basal conditions revealed both a labile and a stable phosphoenzyme component. The rate of decay of the labile component completely accounted for the basal ATPase activity observed. We conclude that the basal ATPase associated with our preparations is a spontaneous dephosphorylation of the phosphoenzyme occurring in the absence of K+ and that the H+/ATP stoichiometry of the gastric ATPase is one.