Transcranial Doppler Velocities and Angiographic Vasospasm after SAH: A Diagnostic Accuracy Study.

BACKGROUND AND PURPOSE: After aneurysmal SAH, transcranial Doppler is commonly used to monitor cerebral vasospasm. The diagnostic accuracy of transcranial Doppler flow velocity values in detecting angiographic vasospasm in patients requiring urgent endovascular intervention has not been established. MATERIALS AND METHODS: We performed a retrospective analysis of a consecutive series of patients with aneurysmal SAH who underwent transcranial Doppler (index test) within 24 hours of conventional angiography (reference test). The judgment of 33%, 50%, and 66% degree of vessel narrowing on angiography was independently established by multiple neuroendovascular clinicians. Vessel-specific per-segment and per-patient transcranial Doppler velocities were studied using receiver operating characteristic curves, the Youden index, and minimal acceptable sensitivity models. Optimal mean flow-velocity thresholds were explored to calculate sensitivity and specificity using a per-patient judgment of vasospasm of at least 50% angiographic narrowing in any large arterial segment except A1. RESULTS: In 221 patients, vasospasm was found in 15%, 8%, and 4% of arteries when the degree of reference angiographic luminal narrowing was 33%, 50%, and 66%, respectively. Mean flow velocities were significantly higher in vasospastic segments (P = . 001), but per-segment exploratory analyses yielded unsound mean flow velocity thresholds. The Youden and minimal acceptable sensitivity models proposed mean flow velocity thresholds of approximately 160 cm/s for the anterior circulation and 80 cm/s for the posterior circulation in the per-patient diagnosis of angiographic vasospasm (≥50%), yielding a sensitivity of 80%-90% (95% CI, 0.77-0.96), but with a corresponding specificity of 50% (95% CI, 0.40-0.56). CONCLUSIONS: In this study, a threshold transcranial Doppler mean flow-velocity value that would accurately diagnose ≥50% angiographic vasospasm remained elusive.

Antibiotic management of acute pharyngitis in primary care.

The Centre for Health Protection of the Department of Health has convened the Advisory Group on Antibiotic Stewardship Programme in Primary Care (the Advisory Group) to formulate guidance notes and strategies for optimising judicious use of antibiotics and enhancing the Antibiotic Stewardship Programme in Primary Care. Acute pharyngitis is one of the most common conditions among out-patients in primary care in Hong Kong. Practical recommendations on the diagnosis and antibiotic treatment of acute streptococcal pharyngitis are made by the Advisory Group based on the best available clinical evidence, local prevalence of pathogens and associated antibiotic susceptibility profiles, and common local practice.

Canadian perspectives: update on inhibition of ALK-positive tumours in advanced non-small-cell lung cancer.

Background: Inhibition of the anaplastic lymphoma kinase (alk) oncogenic driver in advanced non-small-cell lung carcinoma (nsclc) improves survival. In 2015, Canadian thoracic oncology specialists published a consensus guideline about the identification and treatment of ALK-positive patients, recommending use of the alk inhibitor crizotinib in the first line. New scientific literature warrants a consensus update. Methods: Clinical trials of alk inhibitor were reviewed to assess benefits, risks, and implications relative to current Canadian guidance in patients with ALK-positive nsclc. Results: Randomized phase iii trials have demonstrated clinical benefit for single-agent alectinib and ceritinib used in treatment-naïve patients and as second-line therapy after crizotinib. Phase ii trials have demonstrated activity for single-agent brigatinib and lorlatinib in further lines of therapy. Improved responses in brain metastases were observed for all second- and next/third-generation alk tyrosine kinase inhibitors in patients progressing on crizotinib. Canadian recommendations are therefore revised as follows:■ Patients with advanced nonsquamous nsclc have to be tested for the presence of an ALK rearrangement.■ Treatment-naïve patients with ALK-positive disease should initially be offered single-agent alectinib or ceritinib, or both sequentially.■ Crizotinib-refractory patients should be treated with single-agent alectinib or ceritinib, or both sequentially.■ Further treatments could include single-agent brigatinib or lorlatinib, or both sequentially.■ Patients progressing on alk tyrosine kinase inhibitors should be considered for pemetrexed-based chemotherapy.■ Other systemic therapies should be exhausted before immunotherapy is considered. Summary: Multiple lines of alk inhibition are now recommended for patients with advanced nsclc with an ALK rearrangement.

(18)F-fluorodeoxyglucose positron-emission tomography-computed tomography to diagnose recurrent cancer.

BACKGROUND: Sometimes the diagnosis of recurrent cancer in patients with a previous malignancy can be challenging. This prospective cohort study assessed the clinical utility of (18)F-fluorodeoxyglucose positron-emission tomography-computed tomography ((18)F-FDG PET-CT) in the diagnosis of clinically suspected recurrence of cancer. METHODS: Patients were eligible if cancer recurrence (non-small-cell lung (NSCL), breast, head and neck, ovarian, oesophageal, Hodgkin's or non-Hodgkin's lymphoma) was suspected clinically, and if conventional imaging was non-diagnostic. Clinicians were asked to indicate their management plan before and after (18)F-FDG PET-CT scanning. The primary outcome was change in planned management after (18)F-FDG PET-CT. RESULTS: Between April 2009 and June 2011, 101 patients (age, median 65 years; 55% female) were enroled from four cancer centres in Ontario, Canada. Distribution by primary tumour type was: NSCL (55%), breast (19%), ovarian (10%), oesophageal (6%), lymphoma (6%), and head and neck (4%). Of the 99 subjects who underwent (18)F-FDG PET-CT, planned management changed after (18)F-FDG PET-CT in 52 subjects (53%, 95% confidence interval (CI), 42-63%); a major change in plan from no treatment to treatment was observed in 38 subjects (38%, 95% CI, 29-49%), and was typically associated with (18)F-FDG PET-CT findings that were positive for recurrent cancer (37 subjects). After 3 months, the stated post-(18)F-FDG PET-CT management plan was actually completed in 88 subjects (89%, 95% CI, 81-94%). CONCLUSION: In patients with suspected cancer recurrence and conventional imaging that is non-diagnostic, (18)F-FDG PET-CT often provides new information that leads to important changes in patient management.

Polar freshwater cyanophage S-EIV1 represents a new widespread evolutionary lineage of phages.

Cyanobacteria are often the dominant phototrophs in polar freshwater communities; yet, the phages that infect them remain unknown. Here, we present a genomic and morphological characterization of cyanophage S-EIV1 that was isolated from freshwaters on Ellesmere Island (Nunavut, High Arctic Canada), and which infects the polar Synechococcus sp., strain PCCC-A2c. S-EIV1 represents a newly discovered evolutionary lineage of bacteriophages whose representatives are widespread in aquatic systems. Among the 130 predicted open reading frames (ORFs) there is no recognizable similarity to genes that encode structural proteins other than the large terminase subunit and a distant viral morphogenesis protein, indicating that the genes encoding the structural proteins of S-EIV1 are distinct from other viruses. As well, only 19 predicted coding sequences on the 79 178 bp circularly permuted genome have homology with genes encoding proteins of known function. Although S-EIV1 is divergent from other sequenced phage isolates, it shares synteny with phage genes captured on a fosmid from the deep-chlorophyll maximum in the Mediterranean Sea, as well as with an incision element in the genome of Anabaena variabilis (ATCC 29413). Sequence recruitment of metagenomic data indicates that S-EIV1-like viruses are cosmopolitan and abundant in a wide range of aquatic systems, suggesting they have an important ecological role.

Post-translational modifications of PTEN and their potential therapeutic implications.

PTEN is a tumor suppressor gene localized to human chromosome 10q23.31, a genomic region frequently lost in glioblastoma and prostate cancer. The fact that PTEN encodes a lipid phosphatase with specificity towards phosphatidylinositol-3,4,5-triphosphate renders it a gate-keeper of the phosphatidylinositol 3-kinase pathway. Numerous physiological processes have been ascribed to this evolutionarily conserved molecule including proliferation, cell size determination, survival, differentiation, and cell fate specification. Indeed, mutation in PTEN gene is the genetic cause of Cowden Syndrome. Structurally, the 54-kilodalton protein is composed of two major functional domains crucial for catalytic and membrane binding functions. Additional regulatory regions in both amino- and carboxyl-termini further dictate its structural integrity, catalytic activity, and subcellular localization. Extensive characterization of PTEN primary coding sequence has revealed a multitude of post-translational modifications that fine-tune its biochemical properties. These include phosphorylation, ubiquitination, redox modifications, and acetylation. This article aims to provide an in-depth review of the diverse post-translational modifications of PTEN, focusing on their biological relevance in both normal and cancer cells. The potential applications to cancer therapy by modulating the post-translational modifications of PTEN will also be discussed.

Are Hong Kong doctors following the Global Initiative for Asthma guidelines: a questionnaire "Survey on Asthma Management"?

OBJECTIVE: To assess the standard of asthma management by doctors in Hong Kong. DESIGN: Cross-sectional postal questionnaire survey. SETTING: Hong Kong. PARTICIPANTS: Practising doctors registered with the Medical Council of Hong Kong were sent a questionnaire between August and December 2007. MAIN OUTCOME MEASURES: Respondents' responses to questions on demographic data, parameters routinely used to assess asthma control, the pattern of asthma medication prescribing, and seven different case scenarios assessing their ability to classify asthma control and management. RESULTS. We received 410 completed questionnaires from general practitioners (55%), internists (22%), paediatricians (11%), and other specialists (12%). The majority (82%) explained the pathology of asthma to at least some of their patients and tried to identify aggravating factors of the asthma (91%). Fewer observed the inhalation technique of their patients (68%) and prescribed a written asthma management plan (33%). The main medications prescribed to adults and children with asthma were inhaled corticosteroids, inhaled short-acting beta-2 agonists, and combinations of an inhaled corticosteroid and a long-acting beta-2 agonist. In adults and children, long-acting beta-2 agonist alone (without inhaled corticosteroid) was being used to treat asthma by 45% and 36% of the doctors, respectively. Also, 94% of the respondents correctly classified the control status in four out of the seven case scenarios and 31% chose the correct medications when responding to seven of the 14 questions asked. CONCLUSIONS: Asthma management practice of Hong Kong doctors falls short of the standards recommended by international guidelines. More effort in improving their knowledge is urgently warranted.

KLF6, a candidate tumor suppressor gene mutated in prostate cancer.

Kruppel-like factor 6 (KLF6) is a zinc finger transcription factor of unknown function. Here, we show that the KLF6 gene is mutated in a subset of human prostate cancer. Loss-of-heterozygosity analysis revealed that one KLF6 allele is deleted in 77% (17 of 22) of primary prostate tumors. Sequence analysis of the retained KLF6 allele revealed mutations in 71% of these tumors. Functional studies confirm that whereas wild-type KLF6 up-regulates p21 (WAF1/CIP1) in a p53-independent manner and significantly reduces cell proliferation, tumor-derived KLF6 mutants do not. Our data suggest that KLF6 is a tumor suppressor gene involved in human prostate cancer.

Regulation of PTEN binding to MAGI-2 by two putative phosphorylation sites at threonine 382 and 383.

We have reported previously that the PTEN COOH-terminal 33 amino acids play a role in the maintenance of PTEN protein stability (Tolkacheva and Chan, Oncogene, 19: 680-689, 2000). By site-directed mutagenesis, we identified two threonine residues within this COOH-terminal region at codon 382 and 383 that may be targets for phosphorylation events. Interestingly, PTEN mutants rendered phosphorylation-incompetent at these two sites, T382A/T383A, and were found to have drastically reduced expression in cultured cells. The enhanced degradation of PTEN was most likely mediated by the proteosome-dependent pathway, we have evidence that PTEN was polyubiquitinated. More interestingly, the non-phosphorylated forms of PTEN displayed significantly greater binding affinity than the wild-type protein to a previously identified PTEN interacting partner, MAGI-2/ARIP1. On the basis of all these data, we propose that PTEN recruitment to the cell-cell junction may be regulated through the phosphorylation of its COOH terminus.

Axillary vein thrombosis secondary to congenital stricture in a left-sided superior vena cava.

We describe a case of axillary vein thrombosis secondary to unusual venous anatomy. A patient with a strictured left-sided superior vena cava and axillary vein thrombosis was successfully treated with thrombolysis. The underlying stricture was treated with angioplasty and stenting.

R-Ras3, a brain-specific Ras-related protein, activates Akt and promotes cell survival in PC12 cells.

The GTP-binding protein, R-Ras3/M-Ras, is a novel member of the Ras subfamily of GTPases which shows highest sequence similarity to the TC21 gene. R-Ras3 is highly expressed in both human and mouse brain and ectopic expression of a constitutively active mutant of R-Ras3 induces cellular transformation in NIH3T3 cells. To gain further insight into the normal cellular function of R-Ras3, we examined the ability of R-Ras3 in activating several known intracellular signaling cascades. We observed that R-Ras3 is a relatively weak activator of the mitogen-activated protein kinase/extracellular-signal-regulated kinases (MAPK/ERKs) when compared to the H-Ras oncogene. On the contrary, both R-Ras3 and H-Ras activated the Jun N-terminal kinase (JNK) to a similar extent. Under similar experimental conditions, R-Ras3 significantly stimulated one of the phosphatidylinositol 3-kinase (PI3-K) downstream substrates, Akt/PKB/RAC (Akt), which has been extensively implicated in mediating cell survival signaling. The activation of Akt by R-Ras3 was most likely to be PI3-K-dependent since this biochemical event was blocked by the pharmacological inhibitors, Wortmannin and LY294002, as well as by a dominant negative mutant of PI3-K. More importantly, R-Ras3 affinity-precipitated PI3-K from cell extracts in a GTP-dependent manner, and associated lipid kinase activity was readily detectable in R-Ras3 immune complexes. The biological significance of R-Ras3 in inducing Akt kinase activity is evidenced by the ability of an activated R-Ras3 to confer cell survival in the rat pheochromocytoma cell line, PC12. As expected, this biological activity of R-Ras3 was also abrogated by the addition of LY294002. Thus, R-Ras3 represents a novel G-protein which may play a role in cell survival of neural-derived cells.

Regulatory proteins of R-Ras, TC21/R-Ras2, and M-Ras/R-Ras3.

We studied the regulation of three closely related members of Ras family G proteins, R-Ras, TC21 (also known as R-Ras2), and M-Ras (R-Ras3). Guanine nucleotide exchange of R-Ras and TC21 was promoted by RasGRF, C3G, CalDAG-GEFI, CalDAG-GEFII (RasGRP), and CalDAG-GEFIII both in 293T cells and in vitro. By contrast, guanine nucleotide exchange of M-Ras was promoted by the guanine nucleotide exchange factors (GEFs) for the classical Ras (Ha-, K-, and N-), including mSos, RasGRF, CalDAG-GEFII, and CalDAG-GEFIII. GTPase-activating proteins (GAPs) for Ras, Gap1(m), p120 GAP, and NF-1 stimulated all of the R-Ras, TC21, and M-Ras proteins, whereas R-Ras GAP stimulated R-Ras and TC21 but not M-Ras. We did not find any remarkable difference in the subcellular localization of R-Ras, TC21, or M-Ras when these were expressed with a green fluorescent protein tag in 293T cells and MDCK cells. In conclusion, TC21 and R-Ras were regulated by the same GEFs and GAPs, whereas M-Ras was regulated as the classical Ras.

Transforming growth factor-beta 1 suppresses serum deprivation-induced death of A549 cells through differential effects on c-Jun and JNK activities.

Transforming growth factor (TGF)-beta1, a pleiotropic cytokine involved in regulating growth and differentiation, can exert both pro-apoptotic and anti-apoptotic effects depending on the cell type or circumstances. We observed that TGF-beta1 blocked apoptosis resulting from serum withdrawal in A549 human lung carcinoma cells. This was associated with suppression of JNK activation that occurs concomitant with the onset of apoptosis in the absence of TGF-beta1, suggesting that JNK plays an active role in the death process and that TGF-beta1 exerts its protective influence by altering JNK activity. Overexpression of a dominant negative mutant form of SEK1, an upstream activator of JNK, likewise suppressed JNK activation and inhibited apoptosis. Investigation of early events following TGF-beta1 treatment revealed an early induction and phosphorylation of c-Jun that was absent in cells subjected to serum withdrawal alone. That TGF-beta1-induced expression of c-Jun is important for survival was supported by the finding that overexpression of non-phosphosphorylatable dominant negative mutant c-Jun, c-Jun(S73A), attenuated the protective influence of TGF-beta1. Our findings suggest that JNK activation is a late but essential event in serum deprivation-induced apoptosis in A549 cells. TGF-beta1 prevents apoptosis, in part, through the early induction and phosphorylation of c-Jun, which in turn results in attenuated JNK activation.

Inhibition of H-Ras transformation by the PTEN/MMAC1/TEP1 tumor suppressor gene.

The human PTEN/MMAC1/TEP1 (PTEN) tumor suppressor gene encodes a phosphatase with specificity towards the D3 phosphate of phosphatidylinositides. PTEN mutations have been reported in the endometrioid type of uterine tumors which are associated with frequent activations of the Ras oncogenes. In this study, we report the ability of PTEN to potently inhibit H-Ras induced morphological transformation and anchorage-independent growth in NIH3T3 cells. This novel activity of PTEN was correlated more with its ability to suppress the phosphatidylinositol 3-kinase (PI3-K)-dependent signaling cascade, but not the mitogen-activated protein kinase (MAPK) pathway. To define the minimal region in PTEN protein that is responsible for this anti-oncogenic activity, a panel of carboxyl-terminal truncation mutants was generated. While deletions of 4 and 33 amino acids do not have marked effects, removal of up to 68 amino acids drastically reduced the ability of PTEN to inhibit Ras transformation. The propensity of these mutants to suppress Ras transformation is correlated with their relative ability to dephosphorylate inositol (1,3,4,5)-tetrakisphosphate in vitro, and to suppress Akt kinase activity in cultured cells. In addition, we have evidence to suggest that the C-terminal region of PTEN contributes to the stability of the encoded gene product.

Differential roles of Akt, Rac, and Ral in R-Ras-mediated cellular transformation, adhesion, and survival.

Multiple biological functions have been ascribed to the Ras-related G protein R-Ras. These include the ability to transform NIH 3T3 fibroblasts, the promotion of cell adhesion, and the regulation of apoptotic responses in hematopoietic cells. To investigate the signaling mechanisms responsible for these biological phenotypes, we compared three R-Ras effector loop mutants (S61, G63, and C66) for their relative biological and biochemical properties. While the S61 mutant retained the ability to cause transformation, both the G63 and the C66 mutants were defective in this biological activity. On the other hand, while both the S61 and the C66 mutants failed to promote cell adhesion and survival in 32D cells, the G63 mutant retained the ability to induce these biological activities. Thus, the ability of R-Ras to transform cells could be dissociated from its propensity to promote cell adhesion and survival. Although the transformation-competent S61 mutant bound preferentially to c-Raf, it only weakly stimulated the mitogen-activated protein kinase (MAPK) activity, and a dominant negative mutant of MEK did not significantly perturb R-Ras oncogenicity. Instead, a dominant negative mutant of phosphatidylinositol 3-kinase (PI3-K) drastically inhibited the oncogenic potential of R-Ras. Interestingly, the ability of the G63 mutant to induce cell adhesion and survival was closely associated with the PI3-K-dependent signaling cascades. To further delineate R-Ras downstream signaling events, we observed that while a dominant negative mutant of Akt/protein kinase inhibited the ability of R-Ras to promote cell survival, both dominant negative mutants of Rac and Ral suppressed cell adhesion stimulated by R-Ras. Thus, the biological actions of R-Ras are mediated by multiple effectors, with PI3-K-dependent signaling cascades being critical to its functions.

Control of shivering under regional anesthesia in obstetric patients with tramadol.

PURPOSE: Tramadol in a dose of 1 mg x kg(-1) iv is effective in the treatment of shivering after general anesthesia. The current study aimed to investigate (1) whether tramadol was equally effective for shivering under regional anesthesia in obstetric patients and (2) whether effective treatment could be achieved with lower doses. METHODS: In a randomised, double-blind study, 36 obstetric patients who shivered during Cesarean section under regional anesthesia and who requested anti-shivering treatment were allocated to one of three groups for iv treatment: Group T0.5 received tramadol 0.5 mg x kg(-1) (n = 12), Group T0.25 tramadol 0.25 mg x kg(-1) (n = 13) and Group NS normal saline 0.05 ml x kg(-1) (n = 11). Treatment efficacy was evaluated subjectively by the parturient as no improvement, slight improvement, or marked improvement. The attending anesthesiologist who was blinded also independently noted the time elapsed from treatment to the time shivering subsided. Side effects such as nausea, vomiting or sedation and Apgar scores of the newborn were also noted. RESULTS: Eighty percent of parturients in Group T0.5 and 92% in Group T0.25 were judged by observers to have shivering controlled compared with 27% in Group NS (P < 0.001). The response rates of Group T0.5 and Group T0.25 were not different. There was no increased incidence of side effects in the treatment groups. CONCLUSION: We conclude that tramadol iv was effective in the treatment of intraoperative shivering during regional anesthesia for Cesarean section. There was no demonstrable difference in response rate or incidence of side effects between the two doses of 0.5 mg x kg(-1) and 0.25 mg x kg(-1).

Renal dietitians' perspective: identification, prevalence, and intervention for malnutrition in dialysis patients in Texas.

OBJECTIVE: Determine the prevalence of malnutrition per facility standards; examine interventions used to treat malnutrition; and share experiences, concerns, and solutions to problems in the management of malnutrition in dialysis patients in Texas. DESIGN: Structured survey questionnaires. SETTING: 196 outpatient hemodialysis (HD) and 86 peritoneal dialysis (PD) programs in End-Stage Renal Disease (ESRD) Network of Texas, Inc. PARTICIPANTS: Renal dietitians who worked in Texas dialysis facilities that treated chronic, outpatient adult, and pediatric ESRD patients on HD or PD. MEASIRES: Criteria used to identify malnourished patients, prevalence of malnutrition in dialysis recipients, prevalence and types of interventions used to manage malnourished patients, and participation in quality management activities among renal dietitians. RESULTS: For facilities that treated both HD and PD patients in 1996: (1) a significantly greater proportion of PD patients were identified as malnourished than HD patients; (2) facilities that had a high percentage of malnourished HD patients also had a high percentage of malnourished PD patients; (3) a significantly greater proportion of PD patients received commercial nutrition supplements than HD patients; and (4) use of tube feedings, intradialytic parenteral nutrition, intraperitoneal parenteral nutrition, and total parenteral nutrition among HD and PD patients decreased significantly from the past to the current survey year. Renal dietitians shared their experiences, concerns and solutions to problems in the management of malnutrition in this population. CONCLUSION: Results indicate a need to improve the nutritional status of malnourished dialysis patients, to increase consideration of tube feedings as viable nutrient delivery routes, and to maximize involvement of renal dietitians in the quality management process. With the cooperative effort of staff, care givers, patients, and family, early identification and appropriate interventions may improve the nutritional status and quality of life of dialysis patients. This is a US government work. There are no restrictions on its use.

Phages infecting Vibrio vulnificus are abundant and diverse in oysters (Crassostrea virginica) collected from the Gulf of Mexico.

Phages infecting Vibrio vulnificus were abundant (> 10(4) phages g of oyster tissue-1) throughout the year in oysters (Crassostrea virginica) collected from estuaries adjacent to the Gulf of Mexico (Apalachicola Bay, Fla.; Mobile Bay, Ala.; and Black Bay, La.). Estimates of abundance ranged from 10(1) to 10(5) phages g of oyster tissue-1 and were dependent on the bacterial strain used to assay the sample. V. vulnificus was near or below detection limits (< 0.3 cell g-1) from January through March and was most abundant (10(3) to 10(4) cells g-1) during the summer and fall, when phage abundances also tended to be greatest. The phages isolated were specific to strains of V. vulnificus, except for one isolate that caused lysis in a few strains of V. parahaemolyticus. Based on morphological evidence obtained by transmission electron microscopy, the isolates belonged to the Podoviridae, Styloviridae, and Myoviridae, three families of double-stranded DNA phages. One newly described morphotype belonging to the Podoviridae appears to be ubiquitous in Gulf Coast oysters. Isolates of this morphotype have an elongated capsid (mean, 258 nm; standard deviation, 4 nm; n = 35), with some isolates having a relatively broad host range among strains of V. vulnificus. Results from this study indicate that a morphologically diverse group of phages which infect V. vulnificus is abundant and widely distributed in oysters from estuaries bordering the northeastern Gulf of Mexico.