Presence of optrA-mediated linezolid resistance in multiple lineages and plasmids of Enterococcus faecalis revealed by long read sequencing.

Transferable linezolid resistance due to optrA, poxtA, cfr and cfr-like genes is increasingly detected in enterococci associated with animals and humans globally. We aimed to characterize the genetic environment of optrA in linezolid-resistant Enterococcus faecalis isolates from Scotland. Six linezolid-resistant E. faecalis isolated from urogenital samples were confirmed to carry the optrA gene by PCR. Short read (Illumina) sequencing showed the isolates were genetically distinct (>13900 core SNPs) and belonged to different MLST sequence types. Plasmid contents were examined using hybrid assembly of short and long read (Oxford Nanopore MinION) sequencing technologies. The optrA gene was located on distinct plasmids in each isolate, suggesting that transfer of a single plasmid did not contribute to optrA dissemination in this collection. pTM6294-2, BX5936-1 and pWE0438-1 were similar to optrA-positive plasmids from China and Japan, while the remaining three plasmids had limited similarity to other published examples. We identified the novel Tn6993 transposon in pWE0254-1 carrying linezolid (optrA), macrolide (ermB) and spectinomycin [ANT(9)-Ia] resistance genes. OptrA amino acid sequences differed by 0-20 residues. We report multiple variants of optrA on distinct plasmids in diverse strains of E. faecalis. It is important to identify the selection pressures driving the emergence and maintenance of resistance against linezolid to retain the clinical utility of this antibiotic.

AAV2/1 CD74 Gene Transfer Reduces ß-amyloidosis and Improves Learning and Memory in a Mouse Model of Alzheimer's Disease.

Modulation of the amyloid-ß (Aß) trafficking pathway heralds a new therapeutic frontier for Alzheimer's disease (AD). As CD74 binds to the amyloid-ß precursor protein (APP) and can suppresses Aß processing, we investigated whether recombinant adeno-associated virus (AAV) delivery of CD74 could reduce Aß production and affect disease outcomes. This idea was tested in a mouse AD model. Cotransduction of AAV-tetracycline-controlled transactivator (tTA) and AAV-tet-response element (TRE)-CD74 resulted in CD74 expression, reduced Aß production in mouse neurons containing the human APP with familial AD-linked mutations. Stereotaxic injection of AAV-TRE-GFP or CD74 into the hippocampi of an AD mouse, defined as a TgCRND8 × calmodulin-dependent protein kinase II derived promoter-tTA double-transgenic, reduced Aß loads and pyramidal neuronal Aß accumulation in the hippocampus. Immunofluorescent studies showed that APP colocalization with Lamp1 was increased in CD74-expressing neurons. Moreover, Morris water maze tasks demonstrated that mice treated with AAV-TRE-CD74 showed improved learning and memory compared to AAV-TRE-GFP control animals. These results support the idea that CD74-induced alteration of Aß processing could improve AD-associated memory deficits as shown in mouse models of human disease.

Presenilin-1 familial Alzheimer's disease mutation alters hippocampal neurogenesis and memory function in CCL2 null mice.

Aberrations in hippocampal neurogenesis are associated with learning and memory, synaptic plasticity and neurodegeneration in Alzheimer's disease (AD). However, the linkage between them, ß-amyloidosis and neuroinflammation is not well understood. To this end, we generated a mouse overexpressing familial AD (FAD) mutant human presenilin-1 (PS1) crossed with a knockout (KO) of the CC-chemokine ligand 2 (CCL2) gene. The PS1/CCL2KO mice developed robust age-dependent deficits in hippocampal neurogenesis associated with impairments in learning and memory, synaptic plasticity and long-term potentiation. Neurogliogenesis gene profiling supported ß-amyloid independent pathways for FAD-associated deficits in hippocampal neurogenesis. We conclude that these PS1/CCL2KO mice are suitable for studies linking host genetics, immunity and hippocampal function.

Pathologic processing of the total mesorectal excision.

Total mesorectal excision (TME) is the current optimal surgical treatment for patients with rectal carcinoma. A complete TME is related to lower local recurrence rates and increased patient survival. Many confounding factors in the patient's anatomy and prior therapy can make it difficult to obtain a perfect plane, and thus a complete TME. The resection specimen can be thoroughly evaluated, grossly and microscopically, to identify substandard surgical outcomes and increased risk of local recurrence. Complete and accurate data reporting is critical for patient care and helps surgeons improve their technique.

CCL2 affects ß-amyloidosis and progressive neurocognitive dysfunction in a mouse model of Alzheimer's disease.

Neuroinflammation affects the pathobiology of Alzheimer's disease (AD). Notably, ß-amyloid (Aß) deposition induces microglial activation and the subsequent production of proinflammatory neurotoxic factors. In maintaining brain homeostasis, microglial plasticity also enables phenotypic transition between toxic and trophic activation states. One important control for such cell activation is through the CC-chemokine ligand 2 (CCL2) and its receptor, the CC-chemokine receptor 2. Both affect microglia and peripheral macrophage immune responses and for the latter, cell ingress across the blood-brain barrier. However, how CCL2-CC-chemokine receptor 2 signaling contributes to AD pathogenesis is not well understood. To this end, we now report that CCL2 deficiency influences behavioral abnormalities and disease progression in Aß precursor protein/presenilin-1 double-transgenic mice. Here, increased cortical and hippocampal Aß deposition is coincident with the formulation of Aß oligomers. Deficits in peripheral Aß clearance and in scavenger, neuroprogenitor, and microglial cell functions are linked to deficient Aß uptake. All serve to accelerate memory dysfunction. Taken together, these data support a role of CCL2 in innate immune functions relevant to AD pathogenesis.

Intra-articular injection of hyaluronic acid is not superior to saline solution injection for ankle arthritis: a randomized, double-blind, placebo-controlled study.

BACKGROUND: Intra-articular injections of hyaluronic acid are potentially useful to treat ankle osteoarthritis, yet their effectiveness has not been proven. Both single and multiple-dose treatments for ankle arthritis with use of various hyaluronic acid products have been recommended, but few high-quality studies have been published. The aim of this study was to compare the effectiveness of a single intra-articular injection of hyaluronic acid with a single intra-articular injection of normal saline solution (placebo) for osteoarthritis of the ankle. METHODS: Sixty-four patients with ankle osteoarthritis who met all study criteria were randomly assigned to a single intra-articular injection of 2.5 mL of low-molecular-weight, non-cross-linked hyaluronic acid or a single intra-articular injection of 2.5 mL of normal saline solution. The primary outcome measure was the change from baseline in the American Orthopaedic Foot & Ankle Society (AOFAS) clinical rating score at the six-week and twelve-week follow-up examination. Secondary outcome measures included the Ankle Osteoarthritis Scale score and patient-reported pain with use of a visual analog pain scale. RESULTS: Of the sixty-four patients randomized and treated, eight patients withdrew, leaving fifty-six patients who completed the entire study. There was one mild adverse event (1.6%) among the sixty-four patients. At six weeks and twelve weeks, the mean AOFAS scores in the hyaluronic acid group had improved from baseline by 4.9 and 4.9 points, respectively, whereas the mean AOFAS scores in the placebo group initially worsened by 0.4 point at six weeks and then improved by 5.4 points at twelve weeks. While the change at twelve weeks from baseline was substantial for both groups, the between-group differences were not significant. CONCLUSIONS: We found that a single intra-articular injection of low-molecular-weight, non-cross-linked hyaluronic acid is not demonstrably superior to a single intra-articular injection of saline solution for the treatment of osteoarthritis of the ankle.

The sensitivity and specificity of sentinel lymph node biopsy for breast cancer at Baylor University Medical Center at Dallas: a retrospective review of 488 cases.

Sentinel lymph node (SLN) biopsy has become the standard of care for breast carcinoma management, as it precludes the negative morbid effects-including decreased shoulder range of motion, lymphedema, and paresthesias-of unnecessary axillary lymph node dissection. However, the method of pathologic evaluation of the lymph node has been scrutinized to obtain the greatest sensitivity, specificity, and negative predictive value, ultimately for the benefit of the patient. This retrospective study analyzed 488 biopsies completed by two surgeons and read by multiple pathologists affiliated with Pathologists Biomedical Laboratories. When metastatic disease was not grossly obvious, analysis of the SLN began with touch imprint cytology and, if necessary, a frozen section analysis. On the subsequent day, three levels of the SLN were analyzed with hematoxylin and eosin stain and immunohistochemistry with cytokeratin AE1-3 and the appropriate control. Touch imprint cytology and/or frozen section analysis (where applicable) correctly identified 78 of 89 macrometastases, with a sensitivity of 88%, specificity of 100%, and negative predictive value of 97%. Sensitivity was 72% for micrometastases and 60% for isolated tumor cells, each with 100% specificity. In conclusion, the sensitivity and specificity of SLN biopsy at our institution compares with the higher end of percentages reported in the literature.

Transient tadpole pupil associated with primary uncomplicated medial rectus reattachment.

The authors report a case of reversible tadpole pupil, which occurred during a routine primary uncomplicated bimedial recession in a 2½-year-old child. This case highlights a phenomenon underreported by the ophthalmic community significant in the assessment of depth of anesthesia.

Periorbital necrotizing fasciitis: outcomes using a CT-guided surgical debridement approach.

PURPOSE: The surgical management of necrotizing fasciitis usually involves early radical/wide and aggressive debridement of involved areas. We describe 5 cases of periorbital necrotizing fasciitis (NF), managed using a computed tomographic (CT)-guided approach to surgical debridement. METHODS: Retrospective case series review. RESULTS: Five patients (4 female, 1 male; age range 39-81) were treated for periorbital NF. The diagnosis was confirmed in all cases with blood cultures and wound swabs. All patients were managed medically by a surviving sepsis regimen. CT scans confirmed suprafascial infection and excluded orbital cellulitis. Four patients had minimal surgical debridement to the surface muscle. All patients survived. Four out of 5 patients underwent delayed reconstruction. CONCLUSIONS: Periorbital NF behaves differently from NF of other areas. CT-guided surgical debridement of the superficial muscle maximizes preservation of healthy tissue and facilitates reconstruction. Delayed reconstruction allows fibrosis to settle and good cosmetic and functional results are possible. However, NF remains potentially lethal and close observation and a flexible management plan are required.

The convex retina: optical coherence tomography in hypermetropic shift, without choroidal folds, from intraconal cavernous haemangioma.

A 36-year-old female referred with improving unaided vision in her left myopic eye was found to have a left 4.5 diopter hypermetropic shift. Examination revealed a left 2 mm proptosis but was otherwise normal with no choroidal folds on fundoscopy and bilateral 6/5 corrected vision. Her visual field and B scan image were also unremarkable. Optical Coherence Tomography (OCT) imaging demonstrated left-sided anterior retinal bowing with a convex retinal appearance. Magnetic Resonance Imaging (MRI) confirmed a well-circumscribed intraconal mass. The intraconal mass was successfully removed via lateral orbitotomy and confirmed as a cavernous haemangioma on histological assessment. We document these OCT findings and review published ultrasound detected scleral deformation from similar retro-orbital mass cases.

Systematic review of the effectiveness of population screening for colorectal cancer.

AIM: To estimate the effectiveness of colorectal cancer screening with faecal occult blood testing (FOBT), flexible sigmoidoscopy (FS), and combinations of FOBT and FS in preventing colorectal cancer (CRC) deaths. METHOD: A systematic review was conducted examining randomised controlled trials (RCTs) published between 1997 and 2004 inclusive. A systematic search of Medline, Embase, Current Contents, and the Cochrane Library was undertaken. Studies that evaluated screening with FOBT, FS or combinations of FOBT and FS, were appraised. A meta-analysis of population-based trials of FOBT was conducted. RESULTS: Four RCTs were identified that examined FOBT screening. The three trials that investigated guaiac-based FOBT found CRC mortality was reduced in the screening group. In the two population-based trials, the pooled relative risk was 0.86 (95%CI 0.79-0.93). A fourth RCT was identified, with shorter term follow-up, which considered FOBT screening combined with FS compared with FOBT alone. No significant reduction in CRC mortality was reported in this trial. CONCLUSION: There is high-quality evidence showing that guaiac-based FOBT screening reduces mortality from CRC. No such evidence exists for screening with FS either alone, or in combination with FOBT, but this should be re-evaluated once data become available from four large ongoing trials.

A clinician's approach to clinical ethical reasoning.

We offer a systematic strategy that situates clinical ethical reasoning within the paradigm of clinical reasoning. The trajectory of this strategy parallels clinical reasoning: a plain statement of the initial problem, careful gathering of data, a differential diagnostic assessment, and articulation and confirmation of a justified plan. This approach pays special attention to the goals of medical care, because so much depends on whether or not physician and patient share the same goals. This approach also addresses the heterogeneity of clinical problems that at first appear ethical and acknowledges the ethical pluralism that pervades clinical ethics.

Chronic liver disease mortality attributable to hepatitis B and C in New Zealand.

BACKGROUND: This research aimed to estimate the prevalence and population attributable risk percent (PAR%) of hepatitis B (HBV) and C (HCV) infection among chronic liver disease (CLD) deaths in New Zealand. The PAR% is the percentage of CLD cases attributable to either HBV or HCV. Within New Zealand, there are large differences in HBV prevalence by ethnic group, so prevalence and PAR% estimates were made separately for the three major ethnic groups. METHODS: The study sample was selected from CLD deaths between 1992 and 1997. Data were extracted from hospital records and coroners' reports. The prevalence and PAR% of HBV and HCV were estimated. RESULTS: Data were extracted for 303 of 359 decedents selected for inclusion. Hepatitis B virus and HCV test results were identified in 67 and 43%, respectively. Among those cases tested, the prevalence (and estimated PAR%) of HBV infection was 68% (PAR% 66%) for Pacific people, 54% (PAR% 52%) for Maori and 10% (PAR% 10%) for European New Zealanders. The prevalence (and estimated PAR%) of past or present HCV infection ranged between 8 and 15% (PAR% 8-14%) for the three major ethnic groups. CONCLUSIONS: The present study has demonstrated that HBV and HCV infections are important contributors to CLD mortality in New Zealand. With the introduction of universal hepatitis B vaccination in the late 1980s, we would expect the burden of CLD deaths attributable to HBV to decrease in the future. However, the burden of CLD deaths due to HCV is likely to increase.