Transient anesthetic-induced worsening of existing left-sided weakness in a patient undergoing elective anterior cervical discectomy

The differential diagnosis of new or worsening focal neurologic deficits on emergence from anesthesia is broad. Cerebral ischemia or hemorrhage, focal seizures, and acute metabolic abnormalities can all result in similar neurologic findings. Intravenously administered anesthetic agents also have been reported to cause new or worsening focal neurologic deficits in patients with a history of preexisting deficits. A patient who suffered such a reversible deficit related to anesthesia is presented.     

Large femoral bone loss after hip revision using the uncemented proximally porous-coated Bi-Metric prosthesis: 22 hips followed for a mean of 6 years

Background and purpose Periprosthetic bone loss after uncemented femoral hip revision is a matter of concern. We have used a proximally porous- and hydroxyapatite-coated prosthesis (Bi-Metric) in revision since 1989 and now we report the bone changes. This prosthesis is intended to distribute the forces more evenly and to avoid proximal femoral unloading.Methods 22 patients were unilaterally reoperated because of aseptic loosening. Only patients with a healthy contralateral hip were included. Mean age at revision was 69 (55–80) years. Bone defects were graded by Gustilo-Pasternak and Endo-Klinik classifications. Clinical assessment was performed with Harris hip score. We used radiographs and dual-energy X-ray absorptiometry to evaluate migration, femoral remodeling, and bone mineral density after 72 (30–158) months.Results The mean Harris hip score was 74 (30–100) points at follow-up. Mild thigh discomfort was present in 1 patient and moderate thigh pain in 3 patients. There was no loosening or subsidence. Osteolysis seen at revision had diminished in 19 of the 22 hips at follow-up. We noted a large reduction in bone mineral density. It was most pronounced in Gruen regions 1, 2, 6, and 7.Interpretation Revision with this stem is a reliable procedure; however, we noted a large degree of proximal bone loss that could lead to later mechanical complications or fractures.     

Molecular mechanism of thioredoxin regulation in photosynthetic A2B2-glyceraldehyde-3-phosphate dehydrogenase

Chloroplast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a light-regulated, NAD(P)H-dependent enzyme involved in plant photosynthetic carbon reduction. Unlike lower photosynthetic organisms, which only contain A(4)-GAPDH, the major GAPDH isoform of land plants is made up of A and B subunits, the latter containing a C-terminal extension (CTE) with fundamental regulatory functions. Light-activation of AB-GAPDH depends on the redox state of a pair of cysteines of the CTE, which can form a disulfide bond under control of thioredoxin f, leading to specific inhibition of the NADPH-dependent activity. The tridimensional structure of A(2)B(2)-GAPDH from spinach chloroplasts, crystallized in the oxidized state, shows that each disulfide-containing CTE is docked into a deep cleft between a pair of A and B subunits. The structure of the CTE was derived from crystallographic data and computational modeling and confirmed by site-specific mutagenesis. Structural analysis of oxidized A(2)B(2)-GAPDH and chimeric mutant [A+CTE](4)-GAPDH revealed that Arg-77, which is essential for coenzyme specificity and high NADPH-dependent activity, fails to interact with NADP in these kinetically inhibited GAPDH tetramers and is attracted instead by negative residues of oxidized CTE. Other subtle changes in catalytic domains and overall conformation of the tetramers were noticed in oxidized A(2)B(2)-GAPDH and [A+CTE](4)-GAPDH, compared with fully active A(4)-GAPDH. The CTE is envisioned as a redox-sensitive regulatory domain that can force AB-GAPDH into a kinetically inhibited conformation under oxidizing conditions, which also occur during dark inactivation of the enzyme in vivo.     

Fulminant endogenous <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> endophthalmitis: imaging findings

Endogenous endophthalmitis is a rare but serious complication of Klebsiella pneumoniae infection that has been predominantly reported to occur in diabetic patients of East Asian origin with K. pneumoniae liver abscesses. The clinical symptoms and signs of endogenous endophthalmitis are nonspecific and may mimic other causes of an acute non-traumatic eye. Permanent visual loss and blindness are common sequelae because of delayed diagnosis and treatment. Computed tomography and magnetic resonance imaging can help to differentiate endophthalmitis from other causes of acute non-traumatic eye when the clinical findings are equivocal. Fluid attenuated inversion recovery and diffusion-weighted imaging with apparent diffusion coefficient map are superior to T2-weighted and gadolinium-enhanced T1-weighted sequences in demonstrating intra-ocular abscesses.     

Cricoid cartilage and esophagus: CT scan study of the dynamic variability of their relative positions

Introduction  Cricoid pressure occludes the esophagus (E) by compressing it between the cricoid cartilage (CC) and the body of the sixth cervical vertebra (C6). This technique is used to prevent passive regurgitation during the induction of anesthesia in patients at high risk for regurgitation. Failures of this technique had been described and a possible displacement of the E relative to the CC had been reported, but there is no study about displacement during antero-posterior movements of the head. Aim  The aim of our study was to evaluate the displacement of the CC relative to the cervical E, during flexion and extension movements of the head. Materials and methods  We retrospectively studied X-ray computed tomography (CT) images of 21 patients with suspected cervical trauma. Patients were in the supine position. In the first series of images, the head was positioned at maximal flexion by means of a support placed under the external occipital protuberance. In the second series of images, the head was maintained in extension by means of a support placed under the shoulders. Each position was obtained as far as possible within the limits of pain and restricted movement. In flexion and extension, we used the lowest slice from the cricoid cartilage. The variables measured were: diameters of CC (CD) and E (OD), left and right lateral displacements of E. Results  A total of 13 CT were analyzed. CD and OD as well as OD/OC ratios did not vary significantly in flexion and extension. We noticed 61.5 and 92.3% (respectively in flexion and in extension) of left or right displacement: 23% of patients presented right displacement in both flexion and extension; 38.5% of patients did not present any right displacement in flexion or in extension; 61.5% of patients presented left displacement in both flexion and extension. More generally, almost 92% of patients presented displacement either in flexion or extension, or both. Discussion  In our study, it can be seen that the E is clearly displaced with regard to the CC, that this displacement is favored by extension. Only 2/13 patients have an “over than 3 mm” displacement in extension whereas 5/13 in flexion. So, even if there are more displacements in extension, they are inferior to 3 mm and may not be considered as significant considering the occlusion of E. According to our results, the extension position of the head produces more displacement of the E but should preserve the containment of the cricoid pressure if we consider the thickness of the E wall.     

Injection drug use among street-involved youth in a Canadian setting

Background  

Street-involved youth contend with an array of health and social challenges, including elevated rates of blood-borne infections and mortality. In addition, there has been growing concern regarding high-risk drug use among street-involved youth, in particular injection drug use. We undertook this study to examine the prevalence of injection drug use and associated risks among street-involved youth in Vancouver, Canada.     

Unstable housing and hepatitis C incidence among injection drug users in a Canadian setting

Background  

There has emerged growing recognition of the link between housing and health. Since Vancouver, Canada has had increasing concerns with homelessness brought about by urban renewal in the lead-up to the 2010 Winter Olympic Games, we evaluated hepatitis C virus (HCV) incidence among injection drug users (IDU) with and without stable housing.     

Comprehensive short-term outcome assessment of selective dorsal rhizotomy

This study retrospectively evaluated the safety and efficacy of selective dorsal rhizotomy (SDR) in participants who underwent a rigorous selection process, uniform surgical procedure, and a standardized postoperative rehabilitation process. Outcome measures assessed were the Ashworth scale for spasticity, the Gillette Gait Index (GGI) for overall gait pathology, oxygen cost for gait efficiency, and the Gillette Functional Assessment Questionnaire (functional walking ability scale; [FAQ]) for functional mobility. Outcomes were evaluated for 136 children (81 males, 55 females; mean age 7y 3mo [SD 2y 1mo], range 3y 5mo-18y 9mo) for an average of 18.3 months (SD 4.4mo) postoperatively. All participants had a diagnosis of cerebral palsy (CP): 10 quadriplegia, 19 triplegia, and 107 diplegia. Preoperative Gross Motor Function Classification System levels were: Level I n=6; Level II n=64; Level III n=59, and Level IV n=7. All outcome measures improved for the group as a whole. Spasticity improved with 66 to 92% of possible gain in Ashworth scores; GGI was 7.5 times more likely to have a good as opposed to a poor outcome; energy efficiency improved in over half of the participants, and the FAQ demonstrated a statistically significant improvement of 0.9 levels (p<0.001). The rate of complications was low, with peri- and postoperative complications resolved by time of discharge.