First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment.

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9 GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36 GeV/c^{2}, rejecting cross sections above 9.2×10^{-48} cm at the 90% confidence level.

A novel mechanical inclinometer device to measure acetabular cup inclination in total hip arthroplasty.

It is well recognised that acetabular cup orientation influences patient function and implant survival post-THR. Reliable intra-operative determination of cup orientation remains a challenge. We describe the design and testing of a novel mechanical inclinometer to measure intra-operative acetabular cup inclination. The aim was to design a generic inclinometer to measure acetabular inclination to within + 5° without requiring modification to existing instrumentation while remaining easy to handle, robust/reusable, and sterilizable. The device was drafted using CAD software, prototyped using a 3D printer and constructed using stainless steel. Two experiments were undertaken to test accuracy: (1) the absolute accuracy was tested; (2) placement of an acetabular component using the device was compared to a freehand technique using a sawbone pelvis. 18 surgeons were asked to place an uncemented acetabular cup in a saw bone pelvis to a target of 40°. The average root-mean-square error was 1.1° (SD: 0.9°). Comparison showed that with the freehand component placement 50% of the surgeons were outside the specified range (35°-45°) where all participants achieved placement within range when using the inclinometer. This work demonstrates that the design and initial testing of a mechanical inclinometer which is suitable for use in determining the acetabular cup inclination in THR.

Tuberculosis infection of the talonavicular joint.

Isolated tuberculosis osteomyelitis affecting the foot is extremely rare. Symptoms are nonspecific and haematological investigations are often unhelpful making diagnosis difficult. We report the case of a 41-year-old female who presented with a 7-month history of a painful hindfoot following a minor ankle sprain. Inflammatory markers were mildly raised and initial radiographs showed only some mild narrowing of the talonavicular joint. MRI scanning suggested osteomyelitis centred over the talonavicular joint. Open biopsy confirmed areas of caseous necrosis but no acid-fast bacilli were seen. The final diagnosis was confirmed with culture of mycobacterium tuberculosis. A good recovery was seen following debridement and commencement of anti-tuberculosis chemotherapy. Unless an awareness of this condition exists, the diagnosis and therefore the appropriate treatment can often be delayed which may lead to significant consequences for the patient.

Gene expression in human chondrocytes in late osteoarthritis is changed in both fibrillated and intact cartilage without evidence of generalised chondrocyte hypertrophy.

OBJECTIVES: To investigate changes in gene expression in fibrillated and intact human osteoarthritis (OA) cartilage for evidence of an altered chondrocyte phenotype and hypertrophy. METHODS: Paired osteochondral samples were taken from a high-load site and a low-load site from 25 OA joints and were compared with eight similar paired samples from age-matched controls. Gene expression of key matrix and regulatory genes was analysed by quantitative real-time reverse transcription-polymerase chain reaction on total RNA extracted from the cartilage. RESULTS: There was a major change in chondrocyte gene expression in OA cartilage. SOX9 (38-fold) and aggrecan (4-fold) gene expression were both lower in OA (p<0.001), and collagen I (17-fold) and II (2.5-fold) gene expression were each increased in a subset of OA samples. The major changes in gene expression were similar at the fibrillated high-loaded site and the intact low-loaded site. There was no evidence of a generalised change in OA to proliferative or hypertrophic phenotype as seen in the growth plate, as genes associated with either stage of differentiation were unchanged (PTHrPR), or significantly downregulated (collagen X (14-fold, p<0.002), VEGF (23-fold, p<0.02), BCL-2 (5.6-fold, p<0.001), matrilin-1 (6.5-fold, p<0.001)). In contrast MMP-13 was significantly upregulated in the OA cartilage samples (5.3-fold, p<0.003). CONCLUSIONS: The expression of key chondrocyte genes, including aggrecan and SOX9, was decreased in OA cartilage and the changes were similar in both fibrillated high-loaded and intact low-loaded cartilage on the same joint. However, there was no significant upregulation of type X collagen, and other genes associated with chondrocyte further differentiation and hypertrophy.

A conservative approach for proximal interphalangeal joint arthroplasty.

Access to the proximal interphalangeal joint of the finger for arthroplasty is difficult without detaching its stabilizers or dividing the tendons that cross it, which then require repair and slow rehabilitation. We describe a method that conserves both, so facilitating post-operative rehabilitation.A C-shaped incision is made on the dorsum of the finger. The lateral bands of the extensor expansion are separated from the central slip proximally to the extensor hood. They are then retracted to expose the condyles of the proximal phalanx, which are excised. The PIP joint is then dislocated between the central slip and a lateral band allowing the remainder of the head to be excised. The middle and proximal phalanges are then prepared to accept the prosthesis. The prosthesis is then inserted and the joint is reduced. The lateral bands of the extensor mechanism are sutured back to the central slip before the skin is closed.

Implication of a novel multiprotein Dam1p complex in outer kinetochore function.

Dam1p, Duo1p, and Dad1p can associate with each other physically and are required for both spindle integrity and kinetochore function in budding yeast. Here, we present our purification from yeast extracts of an approximately 245 kD complex containing Dam1p, Duo1p, and Dad1p and Spc19p, Spc34p, and the previously uncharacterized proteins Dad2p and Ask1p. This Dam1p complex appears to be regulated through the phosphorylation of multiple subunits with at least one phosphorylation event changing during the cell cycle. We also find that purified Dam1p complex binds directly to microtubules in vitro with an affinity of approximately 0.5 microM. To demonstrate that subunits of the Dam1p complex are functionally important for mitosis in vivo, we localized Spc19-green fluorescent protein (GFP), Spc34-GFP, Dad2-GFP, and Ask1-GFP to the mitotic spindle and to kinetochores and generated temperature-sensitive mutants of DAD2 and ASK1. These and other analyses implicate the four newly identified subunits and the Dam1p complex as a whole in outer kinetochore function where they are well positioned to facilitate the association of chromosomes with spindle microtubules.

The staged management of complex entero-urinary fistulae.

OBJECTIVE: To present the results of the staged management of complex entero-urinary fistulae. PATIENTS AND METHODS: Ten patients with complex entero-urinary fistulae were reviewed; all patients were referred to a national intestinal failure unit after failed treatment in other centres. Each patient was treated in three stages. The acute stage involved proximal defunctioning and distal drainage of both the gastrointestinal and urinary tracts to isolate the fistula, together with the eradication of sepsis. The recovery stage involved total parenteral nutrition, organ support, radiological planning of surgical reconstruction and intensive nursing. The reconstructive stage followed when the patient was stable, nutritionally replenished and intra-abdominal sepsis was controlled. Surgery was undertaken jointly by urological and gastrointestinal surgeons. RESULTS: The fistulae were treated successfully in all patients, with functional restoration in four, and/or diversion of the gastrointestinal and urological tracts in six. The mean (range) time to reconstruction was 5 (1-20) months. There were no postoperative deaths. CONCLUSION: A staged multidisciplinary approach with delayed reconstruction can achieve a successful outcome in the management of complex entero-urinary fistulae.

Mite-plant associations from the eocene of southern australia.

Acarodomatia or "mite houses" are located on leaves of many present-day angiosperms and are inhabited by mites that may maintain leaf hygiene. Eocene deposits in southern Australia have yielded acarodomatia on fossil leaves of Elaeocarpaceae and Lauraceae and also contain oribatid mites with close affinities to those that inhabit the acarodomatia of the closest living relatives of the fossil plant taxa. The data indicate that mite-plant associations may have been widespread in southern Australia 40 million years ago.