Post-Carotid Endarterectomy Hypertension. Part 1: Association with Pre-operative Clinical, Imaging, and Physiological Parameters.

OBJECTIVE/BACKGROUND: Post-endarterectomy hypertension (PEH) is a well recognised, but poorly understood, phenomenon after carotid endarterectomy (CEA) that is associated with post-operative intracranial haemorrhage, hyperperfusion syndrome, and cardiac complications. The aim of the current study was to identify pre-operative clinical, imaging, and physiological parameters associated with PEH. METHODS: In total, 106 CEA patients undergoing CEA under general anaesthesia underwent pre-operative evaluation of 24 hour ambulatory arterial blood pressure (BP), baroreceptor sensitivity, cerebral autoregulation, and transcranial Doppler measurement of cerebral blood flow velocity (CBFv) and pulsatility index. Patients who met pre-existing criteria for treating PEH after CEA (systolic BP [SBP] > 170 mmHg without symptoms or SBP > 160 mmHg with headache/seizure/neurological deficit) were treated according to a previously established protocol. RESULTS: In total, 40/106 patients (38%) required treatment for PEH at some stage following CEA (26 in theatre recovery [25%], 27 while on the vascular surgical ward [25%]), while seven (7%) had SBP surges > 200 mmHg back on the ward. Patients requiring treatment for PEH had a significantly higher pre-operative SBP (144 ± 11 mmHg vs. 135 ± 13 mmHg; p < .001) and evidence of pre-existing impairment of baroreceptor sensitivity (3.4 ± 1.7 ms/mmHg vs. 5.3 ± 2.8 ms/mmHg; p = .02). However, PEH was not associated with any other pre-operative clinical features, CBFv, or impaired cerebral haemodynamics. Paradoxically, autoregulation was better preserved in patients with PEH. All four cases of hyperperfusion associated symptoms were preceded by PEH. Length of hospital stay was significantly increased in patients with PEH (p < .001). CONCLUSION: In this study, where all patients underwent CEA under general anaesthesia, PEH was associated with poorly controlled pre-operative BP and impaired baroreceptor sensitivity, but not with other peripheral or central haemodynamic parameters, including impaired cerebral autoregulation.

Optimising treatment parameters for Radiofrequency Induced Thermal Therapy (RFiTT): A comparison of the manufacturer's treatment guidance with a locally developed treatment protocol.

OBJECTIVE: Radiofrequency induced Thermal Therapy (RFiTT) is an established endovenous device for the treatment of varicose veins. Our aim was to compare the manufacturer's treatment guidance with a locally developed treatment protocol on early truncal ablation rates between two patient cohorts. METHODS: The study was a retrospective analysis of prospectively collected data from 534 patients treated for incompetent truncal saphenous veins between June 2009 and December 2012. Patients were treated either according to the manufacturer's guidance (Treatment 1), a single pullback rate of ≥1.5 s/cm, or according to local protocol (Treatment 2), repeated vein treatment to visibly occlude the vein lumen. Follow-up at 6 weeks and 12 months included duplex examination, assessment of complications, and pain scores for the first postoperative week. RESULTS: 14 patients did not attend follow-up, leaving 98 patients (142 saphenous trunk treatments) who received Treatment 1 and 422 patients (566 saphenous trunk treatments) who received Treatment 2. The two groups were well matched for age, sex, and preoperative vein parameters. Six week occlusion rates were significantly different, with more treatment failures after Treatment 1 (Treatment 1 5.6% vs. Treatment 2 0.9%; p = .0001). Treatment 1 was more likely to produce incomplete ablation (3.5% vs. 0.9%) and non-ablation (2.1% vs. 0.0%) compared with Treatment 2. No major complications occurred in either group and functional outcomes were otherwise comparable between the two treatment methods. Longer-term follow-up at 12 months in the first 100 patients undergoing Treatment 2 demonstrated maintenance of the early advantage, with partial recanalisations in 9% and 2% for Treatments 1 and 2, respectively. CONCLUSIONS: Six weeks after treatment with RFiTT, a protocol of repeated vein treatments to visibly obliterate the vein lumen produced more reliable venous occlusion compared with manufacturer's guidance. This advantage is maintained at 12 months.

Changes in middle cerebral artery velocity after carotid endarterectomy do not identify patients at high-risk of suffering intracranial haemorrhage or stroke due to hyperperfusion syndrome.

OBJECTIVES: To determine if significant increases in middle cerebral artery velocity (MCAV) or pulsatility index (PI) during and immediately after carotid endarterectomy (CEA) were predictive of patients suffering a stroke due to the hyperperfusion syndrome (HS) or intracerebral haemorrhage (ICH). METHODS: Transcranial Doppler (TCD) mean/peak MCAV and PI were recorded pre-operatively; pre-clamp; 1-min post-declamping; 10-min post-declamping and 30-min post-operatively. The study was divided into two time periods; Group 1 (1995-2007); where there was no formal guidance for managing post-CEA hypertension (PEH) and Group 2 (2008-2012); where written guidelines for treating PEH were available. RESULTS: 11/1024 patients in Group 1 (1.1%) suffered a stroke due to HS/ICH, compared to 0/426 patients (0.0%) in Group 2 (p = 0.02). In Group 1; intra-operative increases >100% in mean/peak MCAV and PI at 1 and 10-min post-clamp release had positive predictive values (PPV) of 1.2%, 6.3% and 20.0% and 2.9%, 8.0% and 16.6% respectively. Post-operatively; a >100% increase in mean and peak MCAV had a PPV of 6.3% and 2.7% respectively. CONCLUSION: We were unable to demonstrate that significant increases in MCAV and PI were able to predict patients at increased risk of suffering a post-operative stroke due to HS or ICH. The provision of written guidance for managing PEH in Group 2 patients was associated with virtual abolition of ICH/HS.

Deep wound infection after proximal femoral fracture: consequences and costs.

The purpose of this study was to assess the impact of deep wound infection after surgery for proximal femoral fracture (PFF) on the patient in terms of mortality and social consequences, and on the National Health Service in terms of financial burden. Sixty-one cases of PFF over a six-year period were complicated with deep surgical wound infection. These cases were compared with a matched control group of 122 patients without infection. Infected cases had greatly increased hospital stay (P<0.001), were 4.5 times less likely to survive to discharge (P=0.002), and if they survived, were three times less likely to return to their original residence (P=0.05). The total cost of treatment per infected case was 24,410 pound sterling compared with 7210 pound sterling for controls (P<0.001). Meticillin-resistant Staphylococcus aureus (MRSA) infection increased admission length and cost compared with non-MRSA infection (P=0.02). Deep wound infection after PFF is a devastating and costly complication for both the patient and the healthcare services. The cost consequences should be considered when allocating resources to trauma services to ensure adequate provision to minimize infection risks and to accommodate treatment costs in this vulnerable group.

Physiological responses of Gracilariopsis longissima (S.G. Gmelin) Steentoft, L.M. Irvine and Farnham (Rhodophyceae) to sub-lethal copper concentrations.

Through a series of comparative experiments the relative effects of copper (Cu) exposure on the growth and physiology (chlorophyll fluorescence, ion leakage, O(2) evolution and pigmentation) of the red seaweed Gracilariopsis longissima was investigated. Of the various physiological end-points measured, growth proved to be the most sensitive with reductions in relative growth rate (RGR) observed at a concentration of 12.5 microg l(-1) Cu, with zero growth above about 300 microg l(-1). A significant increase in ion leakage and reduction in phycobiliprotein concentrations were evident, but only at the highest concentration tested (500 microg l(-1)), at which point shrinkage of apical tips also occurred. Photosynthetic rates, as measured by chlorophyll fluorescence and oxygen evolution, were first impaired at 250 microg l(-1), with a 30% reduction in photosynthetic efficiency (F(v)/F(m)) and a 60% reduction in oxygen evolution. There were no discernible effects on respiration rates or chlorophyll a and beta-carotene content over this concentration range. It was hypothesised that the observed uncoupling of growth and photosynthesis at low Cu concentrations might be explained by the release of dissolved organic matter (DOC), resulting in less available energy for growth. No such increase in DOC was apparent. Alternative explanations to account for the uncoupling, including the diversion of energy for maintenance of cell integrity and induction of protective mechanisms, are discussed.

The home stretch, a first analysis of the nearly completed genome of Rhodobacter sphaeroides 2.4.1.

Rhodobacter sphaeroides 2.4.1 is an alpha-3 purple nonsulfur eubacterium with an extensive metabolic repertoire. Under anaerobic conditions, it is able to grow by photosynthesis, respiration and fermentation. Photosynthesis may be photoheterotrophic using organic compounds as both a carbon and a reducing source, or photoautotrophic using carbon dioxide as the sole carbon source and hydrogen as the source of reducing power. In addition, R. sphaeroides can grow both chemoheterotrophically and chemoautotrophically. The structural components of this metabolically diverse organism and their modes of integrated regulation are encoded by a genome of approximately 4.5 Mb in size. The genome comprises two chromosomes CI and CII (2.9 and 0.9 Mb, respectively) and five other replicons. Sequencing of the genome has been carried out by two groups, the Joint Genome Institute, which carried out shotgun-sequencing of the entire genome and The University of Texas-Houston Medical School, which carried out a targeted sequencing strategy of CII. Here we describe our current understanding of the genome when data from both of these groups are combined. Previous work had suggested that the two chromosomes are equal partners sharing responsibilities for fundamental cellular processes. This view has been reinforced by our preliminary analysis of the virtually completed genome sequence. We also have some evidence to suggest that two of the plasmids, pRS241a and pRS241b encode chromosomal type functions and their role may be more than that of accessory elements, perhaps representing replicons in a transition state.

Microleakage under amalgam restorations lined with Copalite, Amalgambond Plus, and Vitrebond.

To evaluate the effectiveness of 3 cavity-preparation lining agents in reducing microleakage under amalgam restorations, the apices of 64 human molars were sealed with amalgam, and Class V preparations were placed. Following storage and thermocycling, the molars were placed in acid fuchsin for 24 hours, then sectioned longitudinally. Ranked data were used to score dye penetration. A Kruskal-Wallis statistical test was used to compare the three groups to the control. Teeth treated with glass ionomer cement showed a statistically significant increase (p = .0227) in dye penetration. Dye penetration increased when Amalgambond Plus and glass ionomer resin liner were placed under amalgam restorations. No difference in dye penetration was observed when Copalite was applied. Results of this study do not support routine use of these agents under amalgam restorations for control of microleakage.

Rock pool algae: species composition determined by chance?

The algal flora was sampled in 15 intertidal rock pools, selected for habitat uniformity within a limited area. The distribution of species agreed closely with that expected at random, whether examined by the distribution of associations, by nesting, by chequerboarding or by incidence functions. The simplest explanation is that differences in specific composition between the pools are caused by chance.

Making reference: the cohesive use of pronouns in the narrative discourse of hemidecorticate adolescents.

The cohesive use of referential language in narrative production reveals communicative goals as well as specific aspects of language use. A formalism for analyzing pronominal cohesion was developed and applied to the narrative discourse of three hemidecorticate adolescents. The results revealed hemisphere-dependent differences in overall narrative skill as well as distinct individual discourse strategies. Neither left hemidecorticate planned narration in extended discourse units: One demonstrated a linear and highly explicit discourse style with redundant over-statement of referent nouns and the other produced narratives cluttered with pronouns of both correct and ambiguous reference, relying on nonpersonal pronouns at considerable cost to narrative specificity. The right hemidecorticate produced narratives that were more economical in form and richer in content: He was the only subject able to maintain simultaneous story lines with multiple pronouns and referential relationships cohesively embedded. All subjects expressed at least some story content, but only the right hemidecorticate narratives conveyed suggestion and implication as well as explicit statement.

Patients with rheumatic fever recurrences.

An evaluation is made as to the effectiveness of a rheumatic fever followup clinic in preventing recurrences. Forty-nine recurrences are known to have occurred in 228 patients. Oral rather than intramuscular benzathine penicillin prophylaxis, positive oral or pharyngeal culture of Streptococcus pyogenes and large sibship were found to be associated with recurrences.

World climates and food supply variations.

Most areas of famine could be greatly reduced with proper planning. Improvements in food production in nearby relatively favorable areas could alleviate the present situation whereby a disastrous food shortage must become "newsworthy" throughout the world before the ponderous machinery of international assistance and very expensive intercontinental staple grain shipments are made. Such planning would allow man to be far less at the mercy of the annual whims of seasonal weather for his food supply.