Validation and clinical utility of the executive function performance test in persons with traumatic brain injury.

This study examined the relationships between the Executive Function Performance Test (EFPT), the NIH Toolbox Cognitive Function tests, and neuropsychological executive function measures in 182 persons with traumatic brain injury (TBI) and 46 controls to evaluate construct, discriminant, and predictive validity. Construct validity: There were moderate correlations between the EFPT and the NIH Toolbox Crystallized (r = -.479), Fluid Tests (r = -.420), and Total Composite Scores (r = -.496). Discriminant validity: Significant differences were found in the EFPT total and sequence scores across control, complicated mild/moderate, and severe TBI groups. We found differences in the organisation score between control and severe, and between mild and severe TBI groups. Both TBI groups had significantly lower scores in safety and judgement than controls. Compared to the controls, the severe TBI group demonstrated significantly lower performance on all instrumental activities of daily living (IADL) tasks. Compared to the mild TBI group, the controls performed better on the medication task, the severe TBI group performed worse in the cooking and telephone tasks. Predictive validity: The EFPT predicted the self-perception of independence measured by the TBI-QOL (beta = -0.49, p < .001) for the severe TBI group. Overall, these data support the validity of the EFPT for use in individuals with TBI.

miR-210 is a target of hypoxia-inducible factors 1 and 2 in renal cancer, regulates ISCU and correlates with good prognosis.

BACKGROUND: Clear cell renal cancer frequently harbours von Hippel-Lindau (VHL) gene mutations, leading to stabilisation of the hypoxia-inducible factors (HIFs) and expression of their target genes. We investigated HIF-1 and HIF-2 in the regulation of microRNA-210 (miR-210), and its clinical relevance in renal tumours. METHODS: RCC4 and 786-O renal cancer cell lines transfected with either an empty vector or functional VHL and incubated in normoxia or hypoxia were examined for miR-210 expression. Hypoxia-inducible factor siRNAs were used to examine their regulation of miR-210. Seventy-one clear cell renal tumours were sequenced for VHL mutations. Expression of miR-210, VHL, CA9, ISCU and Ki-67 were determined by immunohistochemistry and qRT-PCR. RESULTS: In addition to HIF-1 regulating miR-210 in renal cancer, HIF-2 can regulate this microRNA in the absence of HIF-1. MicroRNA-210 is upregulated in renal cancer compared with normal renal cortex tissue. MicroRNA-210 correlates negatively with its gene target ISCU at the protein and mRNA level. MicroRNA-210 correlated with positive outcome variables and negatively with Ki-67. CONCLUSION: We provide further evidence of miR-210 activity in vivo, and show that high miR-210 expression is associated with better clinico-pathological prognostic factors.

Implications of tree expansion in shrubland ecosystems for two generalist avian predators.

Shrublands globally have undergone structural changes due to plant invasions, including the expansion of native trees. Removal of native conifer trees, especially juniper (Juniperus spp.), is occurring across the Great Basin of the western U.S. to support declining sagebrush (Artemisia spp.) habitats and associated wildlife species, such as greater sage-grouse (Centrocercus urophasianus). One justification for conifer removal is that it may improve survival of sagebrush-associated wildlife by reducing the abundance of avian predators. However, the relationship between conifer expansion and predator distributions has not been explicitly evaluated. Further, although structural characteristics of habitat are important for generalist predators, overall prey abundance may also affect habitat use by predators. We examined habitat use of common ravens (Corvus corax) and red-tailed hawks (Buteo jamaicensis), two generalist predators whose populations are increasing in western North America, to variation in structural characteristics and prey distributions in sagebrush habitat that has experienced conifer expansion. Structural characteristics of habitat were important predictors of habitat use for both ravens and red-tailed hawks, whereas measures of prey abundance were unimportant for both species likely because generalist predators can use a wide variety of food resources. Ravens, but not red-tailed hawks, responded positively to increasing cover of juniper and the probability of habitat use was highest (> 0.95) where juniper cover within 100 m was > 20%. Habitat use by red-tailed hawks, but not ravens, was greater near cliffs but was not associated with juniper cover. Our study suggests that the removal of conifer in similar environments may lower the probability of habitat use for ravens, a common predator with significant impacts on many prey species. Therefore, we suggest conifer removal may improve sage-grouse reproductive success and survival depending on responses to conifer removal from other predators. Our results may be reflective of similar changes in rangeland ecosystems around the world undergoing expansion of conifer and other woody vegetation. Though species identities differ from sagebrush habitats, generalist avian predators in other habitats may have similar relationships with structural resources.

Successful treatment of a chronic oroantral fistula infected with extensively drug resistant bacteria using long-term oesophageal tube feeding and several non-conventional treatments in a horse.

BACKGROUND: Chronic oroantral fistulae (OAF) with secondary sinusitis can occur following repulsion of cheek teeth in horses. CASE REPORT: An 8-year-old Andalusian cross gelding presented with an iatrogenic clinical crown fracture of tooth 209, which underwent repulsion of its apical portion (day 0). The horse was treated with intramuscular penicillin and intravenous gentamicin (5 days), followed by oral trimethoprim-sulphonamide (10 days) and then oral doxycycline (14 days). The acute iatrogenic OAF created during the initial repulsion persisted; a chronic OAF was identified on day 24. On day 48, septic sinusitis with multidrug-resistant (MDR) Escherichia coli was confirmed. Although susceptible to enrofloxacin in vitro, 30 days of therapy was unsuccessful. Subsequent serial cultures grew multiple MDR and extensively drug-resistant (XDR) gram-negative microorganisms. Whole-genome sequencing (WGS) revealed multiple sequence types of E. coli, with a range of resistance and virulence genes. The orientation of the OAF, regional osteomyelitis and septic sinusitis were confirmed with computed tomography on day 70. On day 74, enteral nutrition was provided through a cervical oesophagostomy tube for 3 months for prevention of oral feed contamination. The OAF was treated with various alternative therapeutics, including apple cider vinegar, propolis and amikacin impregnated products, until resolution on day 116. CONCLUSION: These non-conventional therapeutics, antimicrobials and long-term oesophagostomy contributed to the successful treatment of a complicated OAF. In the future, WGS may be useful to inform antimicrobial selection when MDR or XDR organisms are identified.

Identification of a family of muscarinic acetylcholine receptor genes.

Complementary DNAs for three different muscarinic acetylcholine receptors were isolated from a rat cerebral cortex library, and the cloned receptors were expressed in mammalian cells. Analysis of human and rat genomic clones indicates that there are at least four functional muscarinic receptor genes and that these genes lack introns in the coding sequence. This gene family provides a new basis for evaluating the diversity of muscarinic mechanisms in the nervous system.

Cloning and expression of the human and rat m5 muscarinic acetylcholine receptor genes.

The human and rat genes for a fifth muscarinic receptor have been cloned and expressed in mammalian cells. The 532 amino acid human protein has 89% sequence identity to the 531 amino acid rat protein and is most closely related to the m3 receptor. Both proteins are encoded by single exons. The receptor has intermediate affinity for pirenzepine and low affinity for AF-DX 116, and it increases metabolism of phosphatidylinositol when stimulated with carbachol. Expression of mRNA has yet to be observed in brain or selected peripheral tissues, suggesting that either it is substantially less abundant than m1-m4 or its distribution is quite different.

Randomised placebo controlled trial of non-invasive ventilation for hypercapnia in cystic fibrosis.

BACKGROUND: The clinical benefits of domiciliary non-invasive positive pressure ventilation (NIV) have not been established in cystic fibrosis (CF). We studied the effects of nocturnal NIV on quality of life (QoL), functional and physiological outcomes in CF subjects with awake hypercapnia (arterial carbon dioxide pressure PaCO2>45 mm Hg). METHODS: In a randomised, placebo controlled, crossover study, eight subjects with CF, mean (SD) age 37 (8) years, body mass index 21.1 (2.6) kg/m2, forced expiratory volume in 1 s 35 (8)% predicted and PaCO2 52 (4) mm Hg received 6 weeks of nocturnal (1) air (placebo), (2) oxygen and (3) NIV. The primary outcome measures were CF specific QoL, daytime sleepiness and exertional dyspnoea. Secondary outcome measures were awake and asleep gas exchange, sleep architecture, lung function and peak exercise capacity. RESULTS: Compared with air, NIV improved the chest symptom score in the CF QoL Questionnaire (mean difference 10; 95% CI 5 to 16; p = 0.002) and the transitional dyspnoea index score (mean difference 3.1; 95% CI 1.2-5.0; p = 0.01). It reduced maximum nocturnal pressure of transcutaneous CO2 (PtcCO2 mean difference -17 mm Hg; 95% CI -7 to -28 mm Hg; p = 0.005) and increased exercise performance on the Modified Shuttle Test (mean difference 83 m; 95% CI 21 to 144 m; p = 0.02). NIV did not improve sleep architecture, lung function or awake PaCO2. CONCLUSION: 6 weeks of nocturnal NIV improves chest symptoms, exertional dyspnoea, nocturnal hypoventilation and peak exercise capacity in adult patients with stable CF with awake hypercapnia. Further studies are required to determine whether or not NIV can improve survival.

Lung volumes in diffuse obstructive pulmonary syndromes.

Lung volumes in irreversible diffuse obstructive pulmonary syndromes (DOPS(I)) have been studied by using an analog of the lung that simulates an 18-breath nitrogen washout. The functional residual capacity (FRC), the dead space volume (Vd), the distribution of ventilation, as well as the pattern of lung emptying have been measured in normal subjects and those with obstructive syndromes. The Vd increased progressively with severity of the obstructive syndrome, as did FRC. For all subjects, both normal and obstructed, the ratio of Vd/FRC remained relatively fixed with the regression line of Vd upon FRC showing a minimal value for Vd of 67 cm(3). Vd increased by an average value of 33 cm(3) per liter of lung volume above this value. The increase in FRC resulted from the increased volume of the poorly ventilated compartment for the most part. X-ray evidence of emphysema was poorly correlated with the changes in Vd or FRC. A significant increase in anatomical Vd in DOPS(I) makes up an appreciable portion of the total Vd (physiological).

Structural studies on human muscle fatty acid binding protein at 1.4 A resolution: binding interactions with three C18 fatty acids.

BACKGROUND: Muscle fatty acid binding protein (M-FABP) is one of a family of cytosolic lipid-binding proteins involved in fatty acid processing. In order to investigate the precise interactions between M-FABP and its ligands and to understand the structural basis of differential binding affinity, we have compared the structures of M-FABP in complex with three C18 fatty acids. RESULTS: We describe the crystal structures of M-FABP in complex with n-octadecanoate (stearate), trans-delta 9-octadecenoate (elaidate) and cis-delta 9-octadecenoate (oleate). These structures were refined using least-squares positional and anisotropic temperature factor refinement to final R-factors of 11.4%, 12.1% and 13.2% respectively for all the data between 8.0 A and 1.4 A resolution. CONCLUSIONS: Stearate, elaidate and oleate each adopt highly similar U-shaped conformations when they bind to M-FABP within a large interior binding cavity, which also contains 13 ordered water molecules. The atomic structure of the protein is virtually identical, regardless of the nature of the bound ligand. The fatty acid is thought to enter the interior cavity of the protein via a portal in its surface while interior solvent is released through a secondary opening. The ligand affinity can be correlated with the conformational energy and the solubility of the bound ligand.

Thermal expansion of hen egg-white lysozyme. Comparison of the 1.9 A resolution structures of the tetragonal form of the enzyme at 100 K and 298 K.

The average structural and dynamic properties of tetragonal hen egg-white lysozyme have been compared, in structures refined at 1.9 A resolution, using data collected at 100 K and 298 K. The molecule expands by 1.8% over this temperature range with the expansion occurring primarily in its small sub-atomic-sized spaces in an anisotropic manner. Hen egg-white lysozyme consists of two domains: domain 1 (residues 40 to 88) is composed primarily of beta-sheet and is observed to expand by only 0.3%; domain 2 (residues 1 to 39 and 89 to 129) is chiefly alpha-helix and is observed to expand by 2.2%. This is consistent with previous observations that proteins composed primarily of alpha-helix expand more with temperature than do those composed primarily of beta-sheet. The largest movement in the molecule is undergone by the two domains of the structure that move further apart as the temperature is raised. This motion is not a cleft opening but rather consists of a tilt by 2.3 degrees of domain 1 away from domain 2. Within the individual domains the largest movement is undergone by loop T1 of domain 2, consisting of residues 17 to 23. This loop moves in the opposite direction to the rest of the molecule as the temperature is raised. Average temperature factors for the room-temperature and low-temperature structures are 15.2 A2 and 8.1 A2, respectively, when all protein atoms are considered, while these values are 14.0 A2 and 7.8 A2, when only main-chain atoms (N, C alpha, C) are taken into account. An examination of the main-chain averaged B-factor per residue shows that residues involved in intermolecular protein-protein contacts, with symmetry-related molecules, have somewhat lower B-factors than the average and undergo smaller than average changes in B-factor as the temperature is lowered.

The three-dimensional structures of a polysaccharide binding antibody to Cryptococcus neoformans and its complex with a peptide from a phage display library: implications for the identification of peptide mimotopes.

The three-dimensional structure of 2H1, a protective monoclonal antibody to Cryptococcus neoformans, has been solved at 2.4 A resolution, in both its unbound form and in complex with the 12 amino acid residue peptide PA1 (GLQYTPSWMLVG). PA1 was previously identified as a potential mimotope of the cryptococcal capsular polysaccharide by screening of a phage display peptide library. Peptide binding is associated with only minor rearrangements of some side-chains and a small shift in the H2 loop of the antibody. The peptide assumes a tightly coiled conformation consisting of one inverse gamma-turn and one type II beta-turn that serves to place the entire peptide motif, consisting of ThrP5, ProP6, TrpP8, MetP9 and LeuP10, into a depression in the antibody combining site. A small number of H-bonds between peptide and antibody contribute to the affinity and specificity. Poor steric complementarity between PA1 and the antibody heavy chain along with the fact that the majority of the interactions between 2H1 and PA1 involve van der Waals interactions with the light chain may explain why this peptide acts as only a partial mimotope of the capsular polysaccharide epitope.

Sarcoidosis and HTLV-1 infection.

An asymptomatic, homosexual, white man was found to have an abnormal chest x ray. A presumptive diagnosis of sarcoidosis was made, but pulmonary function tests and a transbronchial biopsy were normal. He then remained asymptomatic for 10 years until he developed a progressive spastic paraparesis. At this point, antibodies to human T cell lymphotropic virus type 1 (HTLV-1) were identified in the serum and cerebrospinal fluid, and the diagnosis of HTLV-1 associated myelopathy was made, the history suggesting sexual exposure to HTLV-1 many years previously. HTLV-1 is associated with a spectrum of immune related disorders, including a pulmonary sarcoid-like syndrome. Infection with this chronic proinflammatory retrovirus should be considered in the differential diagnosis of all immune disorders in at risk individuals.

Molecular mapping of the 8.12 SLE-associated idiotype specificity at the single amino acid level.

The 8.12 idiotype is expressed in elevated titer in the serum of patients with systemic lupus erythematosus and is a marker for a subpopulation of anti-DNA antibodies that possess a V(lambda)II encoded light chain. This study utilized a eukaryotic expression system to identify the structural basis for expression of this idiotype. Reversion of the 8.12+ DSC light chain to the hslv215.23/DPL11 germline gene reveals that the 8.12 idiotype is encoded in the germline. The 8.12+ DSC and the 8.12 AS17 light chains, both belonging to the V(lambda)II family, were subjected to site directed mutagenesis, to localize amino acids important for expression of the 8.12 idiotype. Point mutations were performed in CDR1, CDR2, FR3 and CDR3, in positions where the 8.12+ DSC differs from the 8.12-AS17. Amino acids in CDR1 and the CDR2 proximal region of FR3, but not the J proximal region of CDR3, play a crucial role in 8.12 reactivity. The 3-D structure of Mcg, a human IgG1, with which DSC shares a sequence homology of 92.3% has been examined to visualize the effect of each of the mutations and to identify the surface on DSC that comprises the idiotype.

Point mutations in the beta chain CDR3 can alter the T cell receptor recognition pattern on an MHC class I/peptide complex over a broad interface area.

To study how the T cell receptor interacts with its cognate ligand, the MHC/peptide complex, we used site directed mutagenesis to generate single point mutants that alter amino acids in the CDR3beta loop of a H-2Kb restricted TCR (N30.7) specific for an immunodominant peptide N52-N59 (VSV8) derived from the vesicular stomatitis virus nucleocapsid. The effect of each mutation on antigen recognition was analyzed using wild type H-2Kb and VSV8 peptide, as well as H-2Kb and VSV8 variants carrying single replacements at residues known to be exposed to the TCR. These analyses revealed that point mutations at some positions in the CDR3beta loop abrogated recognition entirely, while mutations at other CDR3beta positions caused an altered pattern of antigen recognition over a broad area on the MHC/peptide surface. This area included the N-terminus of the peptide, as well as residues of the MHC alpha1 and alpha2 helices flanking this region. Assuming that the N30 TCR docks on the MHC/peptide with an orientation similar to that recently observed in two different TCR-MHC/peptide crystal structures, our findings would suggest that single amino acid alterations within CDR3beta can affect the interaction of the TCR with an MHC surface region distal from the predicted CDR3beta-Kb/VSV8 interface. Such unique recognition capabilities are generated with minimal alterations in the CDR3 loops of the TCR. These observations suggest the hypothesis that extensive changes in the recognition pattern due to small perturbations in the CDR3 structure appears to be a structural strategy for generating a highly diversified TCR repertoire with specificity for a wide variety of antigens.

Cerebrospinal fluid immunoglobulin quotients, kappa/lambda ratios, and viral antibody titres in neurological disease.

A description has been given of cerebrospinal fluid (CSF) immunoglobulins in 355 patients with demyelinating, infectious, neuropathic, and other neurological disorders. An increase in the CSF IgG/albumin quotient was observed in 19/36 (53%) cases of definite multiple sclerosis (MS), in 13/47 (28%) cases of probable or possible MS, in 6/9 (67%) cases of proven herpes simplex viral encephalitis (HSVE), in 3/4 (75%) cases of neurosyphilis, in 1/1 case of subacute sclerosing panencephalitis (SSPE), in 2/9 )22%) cases of other central nervous system infections, and in 2/12 (17%) cases of polyneuritis when compared with a group of 236 patients having other neurological disorders. In constrast, a relative increase in the CSF IgA of IgM was seen only in some of the patients with central nervous system infections. It was also found that the quotient CSF/serum IgG, expressed as a percentage of the CSF/serum albumin, was better in distinguishing patients with definite or suspected MS from those with other neurological disorders than the quotients IgG/albumin or IgG/total protein. The CSF K/lambda ratio and the CSF and serum complement-fixing antibody titre to measles and herpes simplex virus were measured in many of the patients. In general, abnormalities of these measurements were associated with raised IgG/albumin quotients. However, in eight patients with definite or suspected MS, a normal IgG/albumin quotient was found with abnormal CSF K/lambda ratios (6 cases) or abnormal CSF titres of measles antibody (7 cases). In addition, two patients, with HSVE had normal IgG/albumin ratios but detectable herpes antibody in the CSF. These findings suggest that the measurement of the relative concentration of CSF immunoglobulin in combination with the K/lambda ratio and antibody titre to various viruses may supplement each other in the endeavour to detect central nervous system immunglobulin sysnthesis in neurological diseases.

A cDNA encoding the precursor of the rat neuropeptide, neurokinin B.

We have isolated a cDNA clone from a rat cerebral cortex library which encodes the 116 amino acid precursor of the neuropeptide, neurokinin B. The precursor has 68% amino acid homology to the bovine precursor and encodes a single peptide of the tachykinin family. Except for possible small variations at both ends of the message, there appears to be only a single species of neurokinin B mRNA in rat cerebral cortex. In situ hybridization histochemistry indicates that the message is widely distributed in the rat brain in a pattern distinct from that of substance P message.

The use of percutaneous endoscopic gastrostomy (PEG) feeding tubes in patients with neurological disease.

Percutaneous endoscopic gastrostomy (PEG) is being used increasingly in the treatment of patients with neurogenic dysphagia to improve nutrition and prevent choking and aspiration pneumonia. PEG is used in a wide range of general medical conditions, but its role in clinical neurology is sometimes controversial. This paper reviews the place of PEG in the management of 32 patients with a variety of chronic and progressive neurological disorders. All the patients found it to be an effective and acceptable method of feeding that prevented weight loss, reduced chest infections, facilitated nursing care and improved their quality of life. PEG has an important role in neurological rehabilitation.

Glutamate stimulation of 45Ca uptake by rat striatal synaptosomes.

The effects of acidic excitatory amino acids and 60 mM K+ on 45Ca uptake by synaptosomes prepared from rat striatum were examined. Both glutamic acid and 60 mM K+ significantly stimulated the uptake of 45Ca and these effects were antagonized by 30 mM Mg2+ and 0.5 mM La3+ but not by 5 microM tetrodotoxin. Neither kainic acid nor N-methyl-D,L-aspartic acid significantly affected the uptake of 45Ca. The results suggest that glutamate may activate a presynaptic receptor that is directly linked to calcium channels.

Case report: Kaposi's sarcoma: an unusual presentation.

Kaposi's sarcoma (KS) is the most common tumor associated with HIV-1 infection, affecting 30% of HIV-infected homosexual men before the advent of highly active antiretroviral therapy (HAART). In the era of HAART, the incidence of KS has markedly declined. KS usually presents with cutaneous lesions, but it may involve other organs, most commonly the pulmonary and gastrointestinal systems. Isolated pulmonary KS without cutaneous involvement is rare, although intrathoracic KS is seen in up to 75% of patients with KS. We describe an unusual case of a patient with AIDS and isolated endobronchial KS despite a normal arterial pO2, normal pulmonary function tests, no cutaneous KS, and normal chest computed tomographic findings.