A Model of Differential Mammary Growth Initiation by Stat3 and Asymmetric Integrin-α6 Inheritance

Multiple cancer-related genes both promote and paradoxically suppress growth initiation, depending on the cell context. We discover an explanation for how this occurs for one such protein, Stat3, based on asymmetric cell division. Here, we show that Stat3, by Stathmin/PLK-1, regulates mitotic spindle orientation, and we use it to create and test a model for differential growth initiation. We demonstrate that Integrin-α6 is polarized and required for mammary growth initiation. Spindles orient relative to polar Integrin-α6, dividing perpendicularly in normal cells and parallel in tumor-derived cells, resulting in asymmetric or symmetric Integrin-α6 inheritance, respectively. Stat3 inhibition randomizes spindle orientation, which promotes normal growth initiation while reducing tumor-derived growth initiation. Lipid raft disruption depolarizes Integrin-α6, inducing spindle-orientation-independent Integrin-α6 inheritance. Stat3 inhibition no longer affects the growth of these cells, suggesting Stat3 acts through the regulation of spindle orientation to control growth initiation.

Regulation of pH by Carbonic Anhydrase 9 Mediates Survival of Pancreatic Cancer Cells With Activated KRAS in Response to Hypoxia

BACKGROUND & AIMS

Most pancreatic ductal adenocarcinomas (PDACs) express an activated form of KRAS, become hypoxic and dysplastic, and are refractory to chemo and radiation therapies. To survive in the hypoxic environment, PDAC cells upregulate enzymes and transporters involved in pH regulation, including the extracellular facing carbonic anhydrase 9 (CA9). We evaluated the effect of blocking CA9, in combination with administration of gemcitabine, in mouse models of pancreatic cancer.

METHODS

We knocked down expression of KRAS in human (PK-8 and PK-1) PDAC cells with small hairpin RNAs. Human and mouse (Kras^G12D/Pdx1-Cre/Tp53/Rosa^YFP) PDAC cells were incubated with inhibitors of MEK (trametinib) or extracellular signal-regulated kinase (ERK), and some cells were cultured under hypoxic conditions. We measured levels and stability of the hypoxia-inducible factor 1 subunit alpha (HIF1A), endothelial PAS domain 1 protein (EPAS1, also called HIF2A), CA9, solute carrier family 16 member 4 (SLC16A4, also called MCT4), and SLC2A1 (also called GLUT1) by immunoblot analyses. We analyzed intracellular pH (pHi) and extracellular metabolic flux. We knocked down expression of CA9 in PDAC cells, or inhibited CA9 with SLC-0111, incubated them with gemcitabine, and assessed pHi, metabolic flux, and cytotoxicity under normoxic and hypoxic conditions. Cells were also injected into either immune-compromised or immune-competent mice and growth of xenograft tumors was assessed. Tumor fragments derived from patients with PDAC were surgically ligated to the pancreas of mice and the growth of tumors was assessed. We performed tissue microarray analyses of 205 human PDAC samples to measure levels of CA9 and associated expression of genes that regulate hypoxia with outcomes of patients using the Cancer Genome Atlas database.

RESULTS

Under hypoxic conditions, PDAC cells had increased levels of HIF1A and HIF2A, upregulated expression of CA9, and activated glycolysis. Knockdown of KRAS in PDAC cells, or incubation with trametinib, reduced the posttranscriptional stabilization of HIF1A and HIF2A, upregulation of CA9, pHi, and glycolysis in response to hypoxia. CA9 was expressed by 66% of PDAC samples analyzed; high expression of genes associated with metabolic adaptation to hypoxia, including CA9, correlated with significantly reduced survival times of patients. Knockdown or pharmacologic inhibition of CA9 in PDAC cells significantly reduced pHi in cells under hypoxic conditions, decreased gemcitabine-induced glycolysis, and increased their sensitivity to gemcitabine. PDAC cells with knockdown of CA9 formed smaller xenograft tumors in mice, and injection of gemcitabine inhibited tumor growth and significantly increased survival times of mice. In mice with xenograft tumors grown from human PDAC cells, oral administration of SLC-0111 and injection of gemcitabine increased intratumor acidosis and increased cell death. These tumors, and tumors grown from PDAC patient-derived tumor fragments, grew more slowly than xenograft tumors in mice given control agents, resulting in longer survival times. In Kras^G12D/Pdx1-Cre/Tp53/Rosa^YFP genetically modified mice, oral administration of SLC-0111 and injection of gemcitabine reduced numbers of B cells in tumors.

CONCLUSIONS

In response to hypoxia, PDAC cells that express activated KRAS increase expression of CA9, via stabilization of HIF1A and HIF2A, to regulate pH and glycolysis. Disruption of this pathway slows growth of PDAC xenograft tumors in mice and might be developed for treatment of pancreatic cancer.

Targeting Hypoxia-Induced Carbonic Anhydrase IX Enhances Immune-Checkpoint Blockade Locally and Systemically

Treatment strategies involving immune-checkpoint blockade (ICB) have significantly improved survival for a subset of patients across a broad spectrum of advanced solid cancers. Despite this, considerable room for improving response rates remains. The tumor microenvironment (TME) is a hurdle to immune function, as the altered metabolism-related acidic microenvironment of solid tumors decreases immune activity. Here, we determined that expression of the hypoxia-induced, cell-surface pH regulatory enzyme carbonic anhydrase IX (CAIX) is associated with worse overall survival in a cohort of 449 patients with melanoma. We found that targeting CAIX with the small-molecule SLC-0111 reduced glycolytic metabolism of tumor cells and extracellular acidification, resulting in increased immune cell killing. SLC-0111 treatment in combination with immune-checkpoint inhibitors led to the sensitization of tumors to ICB, which led to an enhanced Th1 response, decreased tumor growth, and reduced metastasis. We identified that increased expression of CA9 is associated with a reduced Th1 response in metastatic melanoma and basal-like breast cancer TCGA cohorts. These data suggest that targeting CAIX in the TME in combination with ICB is a potential therapeutic strategy for enhancing response and survival in patients with hypoxic solid malignancies.

Stat3 regulates centrosome clustering in cancer cells via Stathmin/PLK1

Cancer cells frequently have amplified centrosomes that must be clustered together to form a bipolar mitotic spindle, and targeting centrosome clustering is considered a promising therapeutic strategy. A high-content chemical screen for inhibitors of centrosome clustering identified Stattic, a Stat3 inhibitor. Stat3 depletion and inhibition in cancer cell lines and in tumours in vivo caused significant inhibition of centrosome clustering and viability. Here we describe a transcription-independent mechanism for Stat3-mediated centrosome clustering that involves Stathmin, a Stat3 interactor involved in microtubule depolymerization, and the mitotic kinase PLK1. Furthermore, PLK4-driven centrosome amplified breast tumour cells are highly sensitive to Stat3 inhibitors. We have identified an unexpected role of Stat3 in the regulation of centrosome clustering, and this role of Stat3 may be critical in identifying tumours that are sensitive to Stat3 inhibitors.

Clinical outcome scores for arthroscopic femoral osteochondroplasty in femoroacetabular impingement: a quantitative systematic review

BACKGROUND AND AIMS

Femoroacetabular impingement is the abnormal contact of the proximal femur and acetabulum during motion. It causes hip pain and joint degeneration in young patients. This systematic review aims to clarify the clinical effect of arthroscopic femoral osteochondroplasty for cam lesions and to review the available literature for the general medical readership, including providers of primary and secondary care.

METHODS AND RESULTS

Electronic databases were searched for studies of arthroscopic femoral osteochondroplasty in primary femoroacetabular impingement. A total of 2618 article titles, 242 abstracts and 33 full text articles were considered. Ultimately nine studies with clinical outcome scores met the inclusion criteria and were included in the qualitative systematic review. Six studies were suitable for meta-analysis using an inverse variance, random effects model (RevMan software). In the nine studies, improvements were seen in Western Ontario and McMaster Universities Osteoarthritis index, Non-arthritic Hip Score and Modified Harris Hip Scores. Across the six studies suitable for meta-analysis (537 patients), a 24-point weighted mean improvement in Non-arthritic hip score was seen. This yielded a large overall effect size of 1.6.

CONCLUSION

Arthroscopic femoral osteochondroplasty appears to be a beneficial treatment for primary femoroacetabular impingement, with a large effect size seen across six eligible studies.

Controlling equine influenza: policy networks and decision-making during the 2007 Australian equine influenza outbreak

Rapid, evidence-based decision-making is critical during a disease outbreak response; however, compliance by stakeholders is necessary to ensure that such decisions are effective - especially if the response depends on voluntary action. This mixed method study evaluated technical policy decision-making processes during the 2007 outbreak of equine influenza in Australia by identifying and analysing the stakeholder network involved and the factors driving policy decision-making. The study started with a review of the outbreak literature and published policy documents. This identified six policy issues regarding policy modifications or differing interpretations by different state agencies. Data on factors influencing the decision-making process for these six issues and on stakeholder interaction were collected using a pre-tested, semi-structured questionnaire. Face-to-face interviews were conducted with 24 individuals representing 12 industry and government organizations. Quantitative data were analysed using social network analysis. Qualitative data were coded and patterns matched to test a pre-determined general theory using a method called theory-oriented process-tracing. Results revealed that technical policy decisions were framed by social, political, financial, strategic and operational considerations. Industry stakeholders had influence through formal pre-existing channels, yet specific gaps in stakeholder interaction were overcome by reactive alliances formed during the outbreak response but outside the established system. Overall, the crisis management system and response were seen as positive, and 75-100% of individuals interviewed were supportive of, had interest in and considered the outcome as good for the majority of policy decisions, yet only 46-75% of those interviewed considered that they had influence on these decisions. Training to increase awareness and knowledge of emergency animal diseases (EADs) and response systems will improve stakeholder participation in emergency disease management and preparedness for future EAD incursions.

Thrombogenic factors and recurrent coronary events

BACKGROUND

Thrombosis is a pivotal event in the pathogenesis of coronary disease. We hypothesized that the presence of blood factors that reflect enhanced thrombogenic activity would be associated with an increased risk of recurrent coronary events during long-term follow-up of patients who have recovered from myocardial infarction.

METHODS AND RESULTS

We prospectively enrolled 1045 patients 2 months after an index myocardial infarction. Baseline thrombogenic blood tests included 6 hemostatic variables (D-dimer, fibrinogen, factor VII, factor VIIa, von Willebrand factor, and plasminogen activator inhibitor-1), 7 lipid factors [cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, lipoprotein(a), apolipoprotein (apo)A-I, and apoB], and insulin. Patients were followed up for an average of 26 months, with the primary end point being coronary death or nonfatal myocardial infarction, whichever occurred first. The hemostatic, lipid, and insulin parameters were dichotomized into their top and the lower 3 risk quartiles and evaluated for entry into a Cox survivorship model. High levels of D-dimer (hazard ratio, 2.43; 95% CI, 1.49, 3.97) and apoB (hazard ratio, 1.82; 95% CI, 1.10, 3.00) and low levels of apoA-I (hazard ratio, 1.84; 95% CI, 1.10, 3.08) were independently associated with recurrent coronary events in the Cox model after adjustment for 6 relevant clinical covariates.

CONCLUSIONS

Our findings indicate that a procoagulant state, as reflected in elevated levels of D-dimer, and disordered lipid transport, as indicated by low apoA-1 and high apoB levels, contribute independently to recurrent coronary events in postinfarction patients.

Antibacterial activity of lidocaine in mixtures with Diprivan

We have studied the antibacterial activity of different concentrations of 0.005-2% lidocaine (lignocaine) in mixtures with Diprivan (propofol), against micro-organisms commonly implicated in sepsis as a result of extrinsically contaminated Diprivan. Bacterial colony counts were reduced progressively with increasing concentrations of lidocaine. Bacteriostatic and bactericidal concentrations of lidocaine were 0.2-2%. Lidocaine 2% was not bactericidal for one of the seven organisms tested. By inhibiting bacterial replication, lidocaine, when added to Diprivan to reduce pain on injection, may possibly reduce the harmful consequences if extrinsic contamination occurs.

The effect of temperature upon pain during injection of propofol

Propofol has been shown to cause pain on injection. This study investigated the effect of warming propofol to 37 degrees C on the pain of intravenous injection. One hundred and one women on outpatient gynaecology lists were allocated to receive propofol either at room temperature or at 37 degrees C. Warming propofol decreased the incidence of pain on injection by 37% (p < 0.001), and also decreased the severity of pain reported by patients (p < 0.001). We conclude that warming propofol to 37 degrees C provides a simple and safe method of reducing the incidence of pain on injection without the addition of other agents.

Plasma specific gravity for identifying hypovolaemia

To define ranges of plasma specific gravity useful for identifying volume depletion in older adults, plasma specific gravity was measured in 170 young adults (mean age 28 years) and 100 retirees (mean age 81 years), and ranges of values likely to be associated with volume depletion were defined. Subsequently, measurements of plasma specific gravity were made in 68 older emergency room (ER) patients (mean age 74 years), a few of whom had obvious reasons for being hypovolaemic, e.g. dehydrating diarrhoea, and these results were compared to those for the control groups. Ranges for plasma specific gravity useful for identifying volume depletion were designated as possible hypovolaemia (1.0265-1.0279), probable hypovolaemia (1.0280-1.0294), and hypovolaemia (> or = 1.0295). Using these definitions, there were more older ER patients compared to both young and old control group subjects, respectively, with probable hypovolaemia (21% vs. 5% and 8%; p < 0.03) and hypovolaemia (16% vs. 0% and 0%; p < 0.03). This study establishes ranges for plasma specific gravity for young and old adults likely to be associated with hypovolaemia, and shows that based upon measurement of plasma specific gravity, older ER patients may often be hypovolemic even in the absence of obvious fluid-wasting illnesses. Future studies are needed to identify the risk factors for hypovolaemia in ER patients, and more vigorously substantiate the findings of this study.

Tracheal intubation without neuromuscular block in children

We have studied 80 healthy children, aged 2-14 yr, undergoing adenotonsillectomy in a double-blind, randomized design. Tracheal intubation facilitated by either suxamethonium 1.5 mg kg-1 or alfentanil 15 micrograms kg-1 was compared after induction of anaesthesia with propofol 3-4 mg kg-1. The quality of tracheal intubation was graded according to the ease of laryngoscopy, position of the vocal cords, coughing, jaw relaxation and movement of limbs. There were no significant differences in the overall assessment of intubating conditions between the two groups, and all children underwent successful tracheal intubation. Fewer patients coughed (P < 0.014) and limb movement was less common (P < 0.007) after tracheal intubation facilitated by suxamethonium. Alfentanil attenuated the haemodynamic responses to tracheal intubation.

Tracheal intubation after induction of anaesthesia with propofol, alfentanil and i.v. lignocaine

We have assessed tracheal intubating conditions in 60 ASA I or II patients after induction of anaesthesia with propofol 2.5 mg kg-1 and alfentanil 10 or 20 micrograms kg-1 with or without i.v. lignocaine 1 mg kg-1. No neuromuscular blocking agents were administered. Patients were allocated randomly to four groups: group 1 = propofol-alfentanil 10 micrograms kg-1; group 2 = propofol-alfentanil 10 micrograms kg-1-lignocaine 1 mg kg-1; group 3 = propofol-alfentanil 20 micrograms kg-1; group 4 = propofol-alfentanil 20 micrograms kg-1-lignocaine 1 mg kg-1. Intubating conditions were assessed as acceptable or unacceptable on the basis of a scoring system dependent on ease of laryngoscopy, vocal cord position and coughing on insertion of the tracheal tube. Intubating conditions were acceptable in 20%, 73%, 73% and 93% of patients in groups 1-4, respectively. Intubating conditions were better and there was less coughing in the lignocaine group.

Evaluation of a disposable patient-controlled analgesia device in children

A disposable patient-controlled analgesia (PCA) device was evaluated in 20 children after major abdominal, urological and orthopaedic surgery. All patients were given a high dependency level of nursing care in general wards. Efficacy (as assessed by hourly pain scores) was comparable to that achieved in a matched control group of 20 children who used the Graseby PCA system. Safety was confirmed by monitoring arterial oxygen saturation, sedation scores and ventilatory frequency. Morphine consumption was similar with the two techniques, but varied widely between patients. The disposable device has a complementary role to play in the provision of a comprehensive pain relief service for children.

Clinical and electrophysiological assessments in ALS patients

Since the relationships between traditional assessments in ALS patients have not been defined, three clinical and four electrophysiological assessments were performed in a cross-sectional study of 87 ALS patients. The clinical assessments produced Norris ALS scores, muscle strength scores and illness durations (DUR). The electrophysiological assessments produced scores for motor unit interference pattern, denervation potentials, compound muscle action potential, and fasciculations. The individual muscle scores were averaged to produce mean scores, and Spearman rank correlations were performed on the mean scores. The association between Norris ALS and mean muscle strength (MMS) scores is significant (p less than .001, rs = 0.84), and these scores are significantly correlated with mean interference pattern (0.77, 0.82), mean denervation potential (-0.63, -0.70), and mean compound muscle action potential scores (0.55, 0.60), respectively. Correlations between IP and DP scores (-0.71), IP and CMAP scores (0.62), and DP and CMAP (-0.56) scores are also significant. Scatterplots of the data and regression lines suggest linear relationships between each of these assessments. Illness duration and fasciculation scores are not strongly correlated (rs less than 0.55) with any of the other clinical or electrophysiological assessments.

Naloxone and experimental spinal cord injury: effect of varying dose and intensity of injury

We have reported previously that high-dose (10 mg/kg) and megadose naloxone (as high as 150 mg/kg) failed to promote recovery of motor function after spinal cord injury in rat. In view of these negative results, in comparison to some reports of benefit of naloxone in the literature, the present study was undertaken to assess lower doses, using a modified 3 x 4 factorial design, to evaluate a range of lower doses in relation to various intensities of cord injury. Sprague-Dawley rats were assigned randomly to 10 groups (n = 10) relating to two factors: intensity of injury and dosage of naloxone. A dynamic-load injury was induced with a 10-g weight dropped from a height of 2.5 cm, 5.0 cm, or 17.5 cm. Animals were treated with naloxone 1 mg/kg, 4 mg/kg, 10 mg/kg, or saline (control). Tests of motor recovery were carried out weekly for 4 weeks postinjury. Histopathological morphometric analysis of the spinal cords was carried out for measurement of residual gray and white matter at the epicenter of the cord injury. In general, the behavioral data showed no improvement in recovery of function, with the possible exception of naloxone at a dosage of 4 mg/kg (not statistically significant at 4 weeks). Independent of naloxone treatment, there was a significant difference among the three intensities of injury. Pathologically, a difference could not be demonstrated in relation to dosage of naloxone, but as in the case of the behavioral data, a graded response occurred as a function of intensity of injury.

Experimental spinal cord injury: qualitative and quantitative histopathologic evaluation

This study involved a morphometric analysis of an experimental model of spinal cord injury. The spinal cords of rats were injured by a weight drop at T8 level. Animals were sacrificed 4 weeks after injury, and histopathologic examination of the spinal cords was carried out qualitatively and also quantitatively with the aid of computer-assisted morphometry. Total cross-sectional areas of residual gray and white matter were determined at five regularly spaced intervals through the injured cord segment. The histologic findings were correlated with height of weight-drop and motor recovery in the hind limbs at 4 weeks postinjury. The weight-drop injury was found to produce a longitudinally asymmetrical cavitary defect, which was better assessed by a series of cross-sectional profiles than by a single histologic cross-section through the epicenter (site of maximal impact) of the cord injury. There was a strong correlation between height of weight-drop and amount of residual tissue (gray and white matter) at the epicenter. A correlation was also found between height of weight-drop and a composite of residual tissue evaluated at multiple levels through the injury site. By comparison with cross-sectional morphometry at the epicenter, multiple cross-sections, reflecting volume of residual tissue in the longitudinal extent of injury, showed greater statistical correlation with functional (behavioral) outcome. This "volumetric" assessment of the total region of injury is therefore recommended as preferable to a histopathologic evaluation limited to the epicenter.

Risk stratification in patients with first non-Q wave infarction: limited value of the early low level exercise test after uncomplicated infarcts. The Multicenter Post-Infarction Research Group

Risk stratification using clinical and historical variables plus early low level exercise testing was performed in 141 patients with a first non-Q wave myocardial infarction. The 111 patients who performed the exercise test had a 3.6% cardiac mortality rate in the first year compared with 13.3% in the 30 patients who could not exercise (p = 0.063), and a 1 year incidence rate of recurrent cardiac events (cardiac death or recurrent nonfatal myocardial infarction) of 10.8% compared with 23.3% (p = 0.127). Patients who developed ischemia (ST depression or angina) during the test had an increased incidence of cardiac events in the year after the infarction (odds ratio greater than 3, p less than 0.05). When patients were subgrouped by the presence or absence of pulmonary congestion, the discriminatory value of the exercise test was seen to reside primarily in the cohort with pulmonary congestion. For example, ST depression during exercise in this group identified patients with a 71% incidence of cardiac events in the year after the infarction compared with 5.3% for those without ST depression (odds ratio 45, p = 0.002). In the patients without pulmonary congestion, the exercise test had no discriminatory value. It is concluded that early low level exercise testing has a limited role after an uncomplicated non-Q wave infarction, but is useful in patients with clinical markers of higher risk.

Experimental spinal cord injury: effect of a calcium channel antagonist (nicardipine)

Variable benefits from the use of a number of calcium channel blockers in experimental spinal cord injury have been reported. To our knowledge, these agents have not been previously tested in a contusion model of cord injury in which neurological outcome is one of the critical outcome parameters. We carried out preliminary behavioral toxicity testing to identify a range of low, moderate, and high dosage levels of the calcium channel blocker, nicardipine; these dosage levels were to be used subsequently in formal testing. After laminectomy at T8 under general anesthesia in rats, a 10-g weight was dropped from a height of 5 cm onto the spinal cord. The animals were randomly assigned to four groups: control or one of three nicardipine treatment groups: (a) low dose (1 mg/kg, followed by a continuous 23-hour infusion of 0.5 mg/kg/hour), (b) moderate dose (10 mg/kg, followed by 5 mg/kg/hour for 23 hours, and (c) high dose (20 mg/kg, followed by 23-hour infusion of 10 mg/kg/hour). Functional recovery was tested over the course of 4 weeks with the Tarlov scale, the inclined plane, and a sensory-motor battery of tests (combined behavioral score). After sacrifice at 4 weeks, morphometric analysis of residual gray and white matter was performed at the epicenter of the spinal cord injury. Statistical analysis of the behavioral data failed to reveal any differences among the control or nicardipine treatment groups. The morphometric analysis similarly failed to show differences between the control and any treatment group.(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of low-level exercise testing early after acute myocardial infarction in patients taking beta-blocking agents

The value of low-level exercise testing early after acute myocardial infarction (AMI) in 207 patients taking beta-blocking drugs was evaluated in a multicenter study of prognosis after AMI. After stratifying patients according to the absence of significant rales upon admission or pulmonary congestion on the admitting chest x-ray, the results of the exercise test (ability to complete the 9-minute protocol) permitted a large cohort (108 patients, 52% of exercising patients) with no deaths from cardiac causes in the year after AMI to be identified. The results suggest that even in patients taking beta-blocking agents, low-level exercise testing together with clinical stratification has value in identifying a large group of patients with a good prognosis after AMI.

Epidemiology of human T cell leukemia virus type I infection in East Sepik Province, Papua New Guinea

A serological survey of 317 healthy residents of rural Papua New Guinea (PNG) showed a 26% prevalence of antibodies to human T cell leukemia virus type I (HTLV-I). Antibody to HTLV-I was detected in 16% of children less than or equal to 10 years old (including an 18-month-old child) and increased to greater than or equal to 24% in subjects greater than 20 years old. Prospective examination for antibody in 104 residents of one village revealed a seroconversion rate of 13% over a one-year period. The mean titer of antibody in these subjects (1:183) was lower (P less than .0005) than that in persons who were persistently seropositive (1:718). Analysis for clustering of infected subjects suggested that personal contact within the home played a role in the horizontal spread of HTLV-I. These data indicate that HTLV-I infection has a higher prevalence in PNG than in other endemic parts of the world, exposure occurs at an early age, and infection and/or seroconversion is common in adults as well as in children.

Low-level exercise testing after myocardial infarction: usefulness in enhancing clinical risk stratification

Of 866 patients enrolled in our multicenter study, 667 performed a low-level exercise test early after myocardial infarction, most before discharge. Excluding seven patients who died before the test could be considered, there was a 14% 1 year cardiac mortality in 192 patients who did not take the test (150 for medical and 42 for logistic reasons) compared with 5% in those who did (p less than .0001). Of those who took the test, 12% subsequently underwent bypass grafts surgery compared with 14% of those who did not (p greater than .05). Decreased mortality in the year after the infarction in those taking the test was associated with an increase in blood pressure to 110 mm Hg or higher (3% vs 18%; p less than .001), ability to complete the 9 min test (3% vs 8%; p less than .01), and the absence of couplets (4% vs 13%; p less than .05) or any ventricular ectopic depolarizations (4% vs 7%, p less than .05) before, during, or after exercise. Achievement of a blood pressure of 110 mm Hg or higher during exercise in patients with no evidence of pulmonary congestion on the chest x-ray identified a group of 454 patients (70% of those taking the test) with a 1 year cardiac mortality of 1% compared with 13% in the remaining patients (p less than .0001). Logistic models showed that the exercise test contributed independent prognostic information for cardiac death, new infarction, and bypass surgery. Results of low-level exercise testing before hospital discharge combined with clinical features of the infarction can effectively identify patients at low risk for subsequent cardiac mortality.

Bleeding pancreaticoduodenal artery aneurysm

A case of ruptured pancreaticoduodenal artery aneurysm diagnosed by arteriography and successfully treated surgically is presented.

Surgical aspects of carotid-vertebral insufficiency

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