Treatment with PB125® Increases Femoral Long Bone Strength in 15-Month-Old Female Hartley Guinea Pigs.

Nuclear factor-erythroid 2-related factor-2 (Nrf2) is a transcription factor that serves as a master regulator of anti-inflammatory agents, phase I xenobiotic, and phase II antioxidant enzymes, all of which provide a cytoprotective role during disease progression. We hypothesized that oral administration of a purported phytochemical Nrf2-activator, PB125®, would increase long bone strength in aging Hartley guinea pigs, a model prone to musculoskeletal decline. Male (N = 56) and female (N = 56) guinea pigs were randomly assigned to receive daily oral treatment with either PB125® or vehicle control. Animals were treated for a consecutive 3-months (starting at 2-months of age) or 10-months (starting at 5-months of age) and sacrificed at 5-months or 15-months of age, respectively. Outcome measures included: (1) ANY-maze™ enclosure monitoring, (2) quantitative microcomputed tomography, and (3) biomechanical testing. Treatment with PB125® for 10 months resulted in increased long bone strength as determined by ultimate bending stress in female Hartley guinea pigs. In control groups, increasing age resulted in significant effects on geometric and structural properties of long bones, as well as a trending increase in ultimate bending stress. Furthermore, both age and sex had a significant effect on the geometric properties of both cortical and trabecular bone. Collectively, this work suggests that this nutraceutical may serve as a promising target and preventive measure in managing the decline in bone mass and quality documented in aging patients. Auxiliary to this main goal, this work also capitalized upon 5 and 15-month-old male and female animals in the control group to characterize age- and sex-specific differences on long bone geometric, structural, and material properties in this animal model.

Left ventricular morphology influences mortality after the Norwood operation.

BACKGROUND: Within the spectrum of congenital heart disease referred to as hypoplastic left heart syndrome (HLHS), there is variation in the morphology and function of the left ventricle which could influence outcomes after stage I Norwood palliation. OBJECTIVE: To determine if left ventricular (LV) morphology is associated with outcome after stage I Norwood palliation for HLHS. METHODS: Echocardiograms were reviewed from 108 patients who had undergone Norwood palliation at our institution over the past 11 years. Total cardiac diameter, thickness of the interventricular septum (IVS), LV area and LV myocardial area were calculated. Competing risk analysis was performed for survival to a stage II operation and to determine potential predictors. RESULTS: From the Norwood operation up to stage II operation, mortality was predicted by IVS thickness, while the absence of right ventricular (RV) dysfunction was predictive of survival to stage II operation. For the complete pathway, from Norwood to the Fontan operation, mortality was predicted by IVS, a lower RV fractional area change and the presence of significant tricuspid regurgitation. Cardiac transplantation during this period was predicted by a lower RV fractional area change (p = 0.02) and a larger LV area in diastole. CONCLUSIONS: These results indicate that LV hypertrophy and decreased RV function adversely effect survival after the Norwood operation. They suggest that LV morphology, especially septal hypertrophy, can influence outcomes in HLHS and should be considered when evaluating treatment options.

Evidence for a critical period in the development of excitability and potassium currents in mouse lumbar superficial dorsal horn neurons.

The output of superficial dorsal horn (SDH; laminae I-II) neurons is critical for processing nociceptive, thermal, and tactile information. Like other neurons, the combined effects of synaptic inputs and intrinsic membrane properties determine their output. It is well established that peripheral synaptic inputs to SDH neurons undergo extensive reorganization during pre- and postnatal development. It is unclear, however, how membrane properties or the subthreshold whole cell currents that shape SDH neuron output change during this period. Here we assess the intrinsic membrane properties and whole cell currents in mouse SDH neurons during late embryonic and early postnatal development (E15-P25). Transverse slices were prepared from lumbar spinal cord and whole cell recordings were obtained at 32 degrees C. During this developmental period resting membrane potential (RMP) became more hyperpolarized (by approximately 10 mV, E15-E17 vs. P21-P25) and input resistance decreased (1,074 +/- 78 vs. 420 +/- 27 MOmega). In addition, action potential (AP) amplitude and AP afterhyperpolarization increased, whereas AP half-width decreased. Before and after birth (E15-P10), AP discharge evoked by intracellular current injection was limited to a single AP at depolarization onset in many neurons (>41%). In older animals (P11-P25) this changed, with AP discharge consisting of brief bursts at current onset ( approximately 46% of neurons). Investigation of major subthreshold whole cell currents showed the rapid A-type potassium current (I(Ar)) dominated at all ages examined (90% of neurons at E15-E17, decreasing to >50% after P10). I(Ar) expression levels, based on peak current amplitude, increased during development. Steady-state inactivation and activation for I(Ar) were slightly less potent in E15-E17 versus P21-P25 neurons at potentials near RMP (-55 mV). Together, our data indicate that intrinsic properties and I(Ar) expression change dramatically in SDH neurons during development, with the greatest alterations occurring on either side of a critical period, P6-P10.

A review of 15-year experience with anomalous origin of the left coronary artery.

BACKGROUND: Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare condition presenting in infancy with acute myocardial ischaemia. AIMS: A retrospective study was undertaken to assess the presenting features and long-term outcome of all cases of ALCAPA presenting to our institution over a 15-year period. METHODS: All the cases were located using the hospital discharge system and charts were reviewed. RESULTS: The mean age at diagnosis was 4.5 months (2 weeks to 16 months). The predominant presenting symptoms were irritability, pallor, and tachypnoea. The predominant electrocardiogram findings were Q waves and ST segment changes in the anterolateral chest leads. One died from the 11 patients in our series. CONCLUSION: The outcome for surgical re-implantation in infants with a diagnosis of ALCAPA is very good however, early diagnosis is crucial to survival. Although once successfully repaired, patients in general were free of symptoms, ventricular dysfunction was usually present, requiring long-term follow-up.

MRI appearance of muscle denervation.

Muscle denervation results from a variety of causes including trauma, neoplasia, neuropathies, infections, autoimmune processes and vasculitis. Traditionally, the diagnosis of muscle denervation was based on clinical examination and electromyography. Magnetic resonance imaging (MRI) offers a distinct advantage over electromyography, not only in diagnosing muscle denervation, but also in determining its aetiology. MRI demonstrates characteristic signal intensity patterns depending on the stage of muscle denervation. The acute and subacutely denervated muscle shows a high signal intensity pattern on fluid sensitive sequences and normal signal intensity on T1-weighted MRI images. In chronic denervation, muscle atrophy and fatty infiltration demonstrate high signal changes on T1-weighted sequences in association with volume loss. The purpose of this review is to summarise the MRI appearance of denervated muscle, with special emphasis on the signal intensity patterns in acute and subacute muscle denervation.

Recent consensus on the classification of rhinosinusitis--a way forward for research and practice?

Prior classification of rhinitis was into three categories: acute, subacute and chronic rhinosinusitis. The advantages of this classification were obvious but they were offset by some disadvantages. For example, the previous classification did not take account of the mechanisms underlying the condition or the clinical outcome. Hence, there was a need for evidence-based sinusitis classification guidelines. The American Academy of Otolaryngology-Head and Neck Surgery and other related societies published a classification of the condition and suggested clinical research strategies for patients with rhinosinusitis. The main conclusion was that sinusitis should be divided into four categories: acute (bacterial) rhinosinusitis, chronic rhinosinusitis (CRS) without polyps, CRS with polyps, and allergic fungal sinusitis. The aim of this current paper is to discuss the consensus for nomenclature, outline the proposed classification of different types of rhinosinusitis and to suggest some ways that we may audit these guidelines.

Automation of sample mounting for macromolecular crystallography.

A standard sample holder and vial for cryocooled macromolecular crystals has been defined for use with robotic sample changers. This SPINE standard sample holder is a modified version, with added features and specifications, of sample holders in common use. In particular, the SPINE standard meets the precision required for automatic sample exchange and includes a cap that is identified by a two-dimensional datamatrix code as well as an optional vial. At the ESRF, the sample holder standard is in use with the EMBL/ESRF/BM14 robotic sample changer (SC3) which is installed on eight beamlines. The SC3 can hold up to 50 crystals stored in five baskets. A datamatrix reader in the SC3 ensures safe management of the sample flow and facilitates fully automatic screening and characterization of samples. Tools for handling and transporting 50 samples in a dry shipping dewar have been developed. In addition to the SC3, the SPINE sample holder is currently compatible with a number of other robotic sample changers.

A comparison of temporal bone fracture classification systems.

OBJECTIVES: To compare the traditional and otic capsule classification system of temporal bone fractures for clinical relevance. DESIGN: A retrospective review of all patients with a radiological diagnosis of a skull-base fracture over a 5-year period. SETTING: All patients were seen at Beaumont Hospital, the national tertiary referral centre for Neuro-otology. PARTICIPANTS: Patients with a clinical diagnosis of skull fracture were identified from the hospitals in patient enquiry (HIPE) database. Of 338 patients, 31 (9%) were identified as having a temporal bone fracture on high-resolution CT scanning. MAIN OUTCOME AND MEASURES: The rate and distribution of each major clinical complications within each classification system to establish if either one was more clinically useful. RESULTS: Fractures were classified as mixed in 14 (45%), longitudinal in 9 (29%) and horizontal in 8 (26%). Alternatively, 2 (7%) were otic capsule violating and 29 (93%) were otic capsule sparing. Seventeen patients (54.8%) sustained a hearing loss. Seven patients (23%) sustained a facial nerve injury. Four (13%) developed a cerebrospinal fluid (CSF) leak. Of all clinical findings only sensorineural hearing loss occurred significantly more often in the horizontal as opposed to the longitudinal group (P = 0.029) and in the otic violating as opposed to the otic sparing group (P = 0.013). CONCLUSIONS: We acknowledge that the relatively small size of our cohort diminishes the statistical power of our conclusions. However, we found that the otic capsule-based classification system was not significantly better than the traditional system in predicting the likelihood of sustaining specific injuries from fractures of the temporal bone.

Atrioventricular block after transcatheter closure of perimembranous ventricular septal defects.

OBJECTIVE: To look at the presentation, treatment and outcome of patients who developed atrioventricular block after transcatheter closure of a perimembranous ventricular septal defect (PMVSD) with the Amplatzer PMVSD device. SETTING: Three tertiary referral centres for paediatric cardiology in two countries. RESULTS: All three patients presented within 10 days of the procedure. All three patients were treated with intravenous steroids. A permanent pacemaker was inserted in all patients but no pacemaker required activation after two months. CONCLUSION: Complete atrioventricular block occurring in the weeks after device occlusion of a PMVSD appears to resolve quickly. Continued involvement in multicentre device databases is required to monitor safety.

The changing face of lateral sinus thrombosis.

Lateral sinus thrombosis is a life threatening complication of middle ear disease, the presentation, diagnosis and management of which has seen many changes in recent times. While the introduction of antibiotics has been associated with a reduction in the incidence and associated morbidity/mortality of this complication, their use has also altered the clinical features of presentation, consequently diagnosis requires a high index of suspicion. Radiological advances, in particular magnetic resonance imaging and magnetic resonance venography, have improved our ability to diagnose this complication pre-operatively, and now are the diagnostic investigations of choice. Intraoperative sigmoid sinus exploration and removal of all necrotic clot are essential steps of surgical management together with appropriate antimicrobial treatment, however the role of anticoagulation therapy remains controversial. We present four recent cases of sigmoid sinus thrombosis and discuss the clinical presentation, investigation and management of this disease.

Induction of nasal hyper-responsiveness by allergen challenge in allergic rhinitis: the role of afferent and efferent nerves.

BACKGROUND: Hyper-responsiveness of nasal secretory function and volume changes are features of allergic rhinitis (AR) that are mediated in part by neural mechanisms. The finding of nasal hyper-responsiveness in subjects with AR who are currently symptomatic, but not in those who are currently out of season and asymptomatic, suggests that induction of neural reflexes in allergic subjects occurs as a result of allergic inflammation. OBJECTIVES: To investigate whether allergen exposure in subjects with asymptomatic seasonal allergic rhinitis (SAR) may lead to induction of neural reflexes, and to investigate the components of the reflexes involved in this induction. METHODS: Asymptomatic subjects with (out-of-season) SAR underwent a nasal bradykinin challenge, before and 24 h after preceding ipsilateral (n = 11) and contralateral (n = 11) antigen challenge. Challenges were performed and nasal secretions collected using filter paper disks, and changes in nasal minimal cross-sectional area (A(min)) were measured using acoustic rhinometry. RESULTS: Preceding ipsilateral antigen challenge led to the induction of a contralateral secretory reflex (P = 0.01), which was absent in control experiments (P = 0.34). Ipsilateral secretion weights were also enhanced. Preceding contralateral antigen challenge also induced a contralateral secretory reflex (P = 0.03). Enhancement of the reduction in contralateral A(min) was also seen (P = 0.02). Ipsilateral responses were unchanged. CONCLUSIONS: Allergen exposure in asymptomatic allergic subjects leads to induction of neural reflexes, resulting in nasal hyper-responsiveness, which persists beyond the resolution of the acute allergic response. Our data suggest that the mechanisms of allergen-induced hyper-responsiveness involve both afferent and efferent components.

An alternative technique for nasal biopsy.

OBJECTIVES/HYPOTHESIS: The objective was to investigate the effectiveness of co-phenylcaine as a topical anesthetic agent for nasal mucosal biopsy. STUDY DESIGN: A prospective study. METHODS: Nasal mucosal biopsy specimens were taken from a site just anterior to the inferior turbinate following topical anesthesia with co-phenylcaine. All volunteers graded pain according to standard visual analogue scale (0-10) (VAS) scoring, and all were followed up after 24 hours for any epistaxis. RESULTS: Ninety nasal biopsy specimens were removed from 41 patients in all. Eight-two percent did not report any discomfort following this procedure (VAS score, 0). Ten patients reported mild discomfort (VAS scores ranging between, 1 and 3) and only six reported pain (VAS scores ranging from 5 to 7). However, five of these patients agreed to further biopsy and documented no discomfort during the repeat procedure. Only one patient required immediate intervention for hemorrhage after the procedure. In cases in which bleeding occurred (seven patients) it was documented within the first 6 hours, was minimal in content, and was controlled with local pressure. No systemic side effects were experienced. CONCLUSION: Co-phenylcaine is a suitable topical anesthetic agent for nasal mucosal biopsy. Removal of nasal tissue from a site anterior to the inferior turbinate can be performed under direct vision and provides sufficient tissue for histological assessment.

The potential of virtual laryngoscopy in the assessment of vocal cord lesions.

Virtual laryngoscopy is a useful adjunctive radiological tool in the assessment of laryngeal lesions. A total of 10 patients requiring direct laryngoscopy for the investigation of laryngeal lesions underwent preoperative virtual laryngoscopy using three-dimensional reconstruction of two-dimensional computerized tomography (CT) images. All lesions were correctly diagnosed on virtual laryngoscopy before direct laryngoscopy. Its main advantages are that it does not require general anaesthesia, it allows three-dimensional visualization of the airway beyond areas of narrowing and it gives a highly accurate representation of vocal cord lesions, both in terms of definition and spatial representation. Its disadvantages are that it does not provide histology, it requires an air-mucosa interface to produce an image and it cannot identify functional lesions of the vocal cords.

Somatostatin therapy for glomus tumors: a report of two cases.

Glomus tumors of the head and neck are benign vascular lesions that often provide dilemmas in management. The presence of somatostatin receptors on the tumor cell surface has facilitated an additional imaging technique in the form of radiolabeled octreotide scanning. The use of the somatostatin analogue, octreotide, also provides a therapeutic option for inoperable or recurrent tumors. We present two patients, one with a surgically inaccessible tumor that recurred after primary radiotherapy and one who underwent incomplete resection because of the tumor's proximity to the internal carotid artery. Neither tumor has shown further growth 5 and 3 years after treatment with octreotide, respectively.

Crystal structures of penicillin acylase enzyme-substrate complexes: structural insights into the catalytic mechanism.

The crystal structure of penicillin G acylase from Escherichia coli has been determined to a resolution of 1.3 A from a crystal form grown in the presence of ethylene glycol. To study aspects of the substrate specificity and catalytic mechanism of this key biotechnological enzyme, mutants were made to generate inactive protein useful for producing enzyme-substrate complexes. Owing to the intimate association of enzyme activity and precursor processing in this protein family (the Ntn hydrolases), most attempts to alter active-site residues lead to processing defects. Mutation of the invariant residue Arg B263 results in the accumulation of a protein precursor form. However, the mutation of Asn B241, a residue implicated in stabilisation of the tetrahedral intermediate during catalysis, inactivates the enzyme but does not prevent autocatalytic processing or the ability to bind substrates. The crystal structure of the Asn B241 Ala oxyanion hole mutant enzyme has been determined in its native form and in complex with penicillin G and penicillin G sulphoxide. We show that Asn B241 has an important role in maintaining the active site geometry and in productive substrate binding, hence the structure of the mutant protein is a poor model for the Michaelis complex. For this reason, we subsequently solved the structure of the wild-type protein in complex with the slowly processed substrate penicillin G sulphoxide. Analysis of this structure suggests that the reaction mechanism proceeds via direct nucleophilic attack of Ser B1 on the scissile amide and not as previously proposed via a tightly H-bonded water molecule acting as a "virtual" base.

Relationship between intracoronary and peripheral expression of soluble cell adhesion molecules.

BACKGROUND: Elevated levels of soluble cell adhesion molecules (sCAMs) have been reported in various coronary artery disease processes. The principle stimulus for expression of sCAMs is believed to be an inflamed atherosclerotic plaque within the coronary vessel. The relationship between levels of sCAMs in the coronary circulation and the peripheral circulation has not been defined. The primary aim of this study was to define the relationship between levels of sCAMs sampled from the systemic circulation and from the coronary circulation. We also set out to document the acute expression of soluble CAMs following coronary angioplasty with or without stent implantation. METHODS: The coronary sinus was cannulated in patients undergoing LAD angioplasty. Samples were drawn from left coronary ostium (LCO) and coronary sinus (CS) and femoral vein simultaneously before, immediately after and 4 h after the PTCA procedure. Levels of sICAM-1, sVCAM-1, sE-selectin and sP-selectin were measured using ELISA technique. RESULTS: 10 patients (7 male/3 female, 61+/-11 y) entered the study. There was no significant difference in the levels of sICAM-1, sVCAM-1, sE-selectin and sPselectin whether sampled from left coronary ostium, coronary sinus or femoral vein at all time points. There was no significant change in the acute expression of sICAM-1, sVCAM-1 and sE-selectin following coronary angioplasty. Levels of sP-selectin fell significantly during the PTCA procedure (142+/-7 ng/ml to 64+/-6 ng/ml, P<0.001) but then rose again after 4 h and returned toward baseline levels at 24 h. CONCLUSION: Levels of soluble CAMs sampled in the systemic circulation directly reflect levels in the coronary circulation. Coronary angioplasty results in rapid fall in levels of sP-selectin which returns to normal within 24 h following the procedure.

A thermophilic mini-chaperonin contains a conserved polypeptide-binding surface: combined crystallographic and NMR studies of the GroEL apical domain with implications for substrate interactions.

A homologue of the Escherichia coli GroEL apical domain was obtained from thermophilic eubacterium Thermus thermophilus. The domains share 70 % sequence identity (101 out of 145 residues). The thermal stability of the T. thermophilus apical domain (Tm>100 degrees C as evaluated by circular dichroism) is at least 35 degrees C greater than that of the E. coli apical domain (Tm=65 degrees C). The crystal structure of a selenomethione-substituted apical domain from T. thermophilus was determined to a resolution of 1.78 A using multiwavelength-anomalous-diffraction phasing. The structure is similar to that of the E. coli apical domain (root-mean-square deviation 0.45 A based on main-chain atoms). The thermophilic structure contains seven additional salt bridges of which four contain charge-stabilized hydrogen bonds. Only one of the additional salt bridges would face the "Anfinsen cage" in GroEL. High temperatures were exploited to map sites of interactions between the apical domain and molten globules. NMR footprints of apical domain-protein complexes were obtained at elevated temperature using 15N-1H correlation spectra of 15N-labeled apical domain. Footprints employing two polypeptides unrelated in sequence or structure (an insulin monomer and the SRY high-mobility-group box, each partially unfolded at 50 degrees C) are essentially the same and consistent with the peptide-binding surface previously defined in E. coli GroEL and its apical domain-peptide complexes. An additional part of this surface comprising a short N-terminal alpha-helix is observed. The extended footprint rationalizes mutagenesis studies of intact GroEL in which point mutations affecting substrate binding were found outside the "classical" peptide-binding site. Our results demonstrate structural conservation of the apical domain among GroEL homologues and conservation of an extended non-polar surface recognizing diverse polypeptides.

Intracranial complications of acute frontal sinusitis.

Despite advances in the diagnosis and treatment of acute frontal sinusitis, there is still significant occurrence of intracranial complications. Urgent surgical evacuation of any intracranial collection is required; however, the surgical management of the associated sinusitis remains controversial. Ten patients presented to this department over a 12-month period with subdural empyema secondary to acute frontal sinusitis. Four patients had a coexisting Pott's puffy tumour and one patient had a periorbital abscess. Each patient was managed using a multidisciplinary approach. A frontal sinus trephine/drain +/- antral washout was performed at the same time as craniotomy with evacuation of the empyema. With this approach only two patients suffered long-term morbidity in our series, in the form of persistent neurological or cognitive deficit. No patient required a definitive sinus procedure. This study emphasizes the need for the early assessment and intervention of patients with an intracranial complication secondary to acute frontal sinusitis. Further assessment of the underlying sinus disease is indicated during outpatient follow up after the acute episode.