Physiological and behavioural adaptations by big brown bats hibernating in dry rock crevices.

Winter energy stores are finite and factors influencing patterns of activity are important for overwintering energetics and survival. Hibernation patterns (e.g., torpor bout duration and arousal frequency) often depend on microclimate, with more stable hibernacula associated with greater energy savings than less stable hibernacula. We monitored hibernation patterns of individual big brown bats (Eptesicus fuscus; Palisot de Beauvois, 1796) overwintering in rock-crevices that are smaller, drier, and less thermally stable than most known cave hibernacula. While such conditions would be predicted to increase arousal frequency in many hibernators, we did not find support for this. We found that bats were insensitive to changes in hibernacula microclimate (temperature and humidity) while torpid. We also found that the probability of arousal from torpor remained under circadian influence, likely because throughout the winter during arousals, bats commonly exit their hibernacula. We calculated that individuals spend most of their energy on maintaining a torpid body temperature a few degrees above the range of ambient temperatures during steady-state torpor, rather than during arousals as is typical of other small mammalian hibernators. Flight appears to be an important winter activity that may expedite the benefits of euthermic periods and allow for short, physiologically effective arousals. Overall, we found that big brown bats in rock crevices exhibit different hibernation patterns than conspecifics hibernating in buildings and caves.

Association between intraoperative opioid administration and 30-day readmission: a pre-specified analysis of registry data from a healthcare network in New England.

BACKGROUND: The use of intraoperative opioids may influence the rate of postoperative complications. This study evaluated the association between intraoperative opioid dose and the risk of 30-day hospital readmission. METHODS: We conducted a pre-specified analysis of existing registry data for 153 902 surgical cases performed under general anaesthesia at Massachusetts General Hospital and two affiliated medical centres. We examined the association between total intraoperative opioid dose (categorised in quintiles) and 30-day hospital readmission, controlling for several patient-, anaesthetist-, and case-specific factors. RESULTS: Compared with low intraoperative opioid dosing [quintile 1, median (inter-quartile range): 8 (4-9) mg morphine equivalents], exposure to high-dose opioids during surgery [quintile 5: 32 (27-41) equivalents] is an independent predictor of 30-day readmission [odds ratio (OR) 1.15 (95% confidence interval 1.07-1.24); P<0.001]. Ambulatory surgery patients receiving high opioid doses were found to have the greatest adjusted risk of readmission (OR 1.75; P<0.001) with a clear dose-response effect across quintiles (P for trend <0.05), and were more likely to be readmitted early (postoperative days 0-2 vs 3-30; P<0.001). Opioid class modified the association between total opioid dose and readmission, with longer-acting opioids demonstrating a stronger influence (P<0.001). We observed significant practice variability across individual anaesthetists in the utilisation of opioids that could not be explained by patient- and case-specific factors. CONCLUSIONS: High intraoperative opioid dose is a modifiable anaesthetic factor that varies in the practice of individual anaesthetists and affects postoperative outcomes. Conservative standards for intraoperative opioid dosing may reduce the risk of postoperative readmission, particularly in ambulatory surgery.

Association between intraoperative non-depolarising neuromuscular blocking agent dose and 30-day readmission after abdominal surgery.

BACKGROUND: We hypothesised that intraoperative non-depolarising neuromuscular blocking agent (NMBA) dose is associated with 30-day hospital readmission. METHODS: Data from 13,122 adult patients who underwent abdominal surgery under general anaesthesia at a tertiary care hospital were analysed by multivariable regression, to examine the effects of intraoperatively administered NMBA dose on 30-day readmission (primary endpoint), hospital length of stay, and hospital costs. RESULTS: Clinicians used cisatracurium (mean dose [SD] 0.19 mg kg-1 [0.12]), rocuronium (0.83 mg kg-1 [0.53]) and vecuronium (0.14 mg kg-1 [0.07]). Intraoperative administration of NMBAs was dose-dependently associated with higher risk of 30-day hospital readmission (adjusted odds ratio 1.89 [95% Confidence Interval (CI) 1.26-2.84] for 5th quintile vs 1st quintile; P for trend: P<0.001), prolonged hospital length of stay (adjusted incidence rate ratio [aIRR] 1.20 [95% CI 1.11-1.29]; P for trend: P<0.001) and increased hospital costs (aIRR 1.18 [95% CI 1.13-1.24]; P for trend: P<0.001). Admission type (same-day vs inpatient surgery) significantly modified the risk (interaction term: aOR 1.31 [95% CI 1.05-1.63], P=0.02), and the adjusted odds of readmission in patients undergoing ambulatory surgical procedures who received high-dose NMBAs vs low-dose NMBAs amounted to 2.61 [95% CI 1.11-6.17], P for trend: P<0.001. Total intraoperative neostigmine dose increased the risk of 30-day readmission (aOR 1.04 [1.0-1.08], P=0.048). CONCLUSIONS: In a retrospective analysis, high doses of NMBAs given during abdominal surgery was associated with an increased risk of 30-day readmission, particularly in patients undergoing ambulatory surgery.

Comparison of Whole Ovary Cryotreatments for Fertility Preservation.

The goal of this study was to compare a traditional slow-freeze method (TF) with an open unidirectional slow freeze cooling system (UF) for whole ovary cryopreservation. Therefore, whole pig ovaries were randomly assigned to (A) fresh control, (B) traditional slow freeze (TF) or (C) unidirectional slow freeze (UF). Ovaries were perfused with 10% DMSO in Krebs-Ringer. For TF, whole ovaries were placed in specimen jars containing 10% DMSO and placed into a specialized container for freezing filled with propan-2-ol. For UF, whole ovaries were placed within a specially designed container containing 10% DMSO and transferred to a specialized freezing machine (CTE 920). Histological evaluation demonstrated intact morphology of follicles in all groups; however, an overall decrease of follicle numbers in TF (46%) and UF (50%) compared to fresh control. Live/dead assay indicated significantly lower populations of live cells in both TF (60%) and UF (58%) compared to fresh tissue (74%). TUNEL assay confirmed a difference in percentage of apoptotic follicles between fresh and TF, but there was no significant difference between fresh and UF. To improve the structural and functional integrity of whole ovaries, further investigation, especially into directional freezing, is needed. Whole ovary cryopreservation could provide opportunities for women facing fertility loss due to chemo- or radiotherapy treatment.

H1N1 influenza is here.

On 11 June WHO announced that the spread of H1N1 had reached pandemic phase 6. Since then countries around the world have increased their planning and preparedness for the continuing pandemic. Guidelines have been issued and circulated but confusion continues over their interpretation. We need to remind ourselves of the principles behind control measures and educate and reinforce standard infection control procedures in the acute hospital setting.

HIV subtypes in Scotland, 2000-2006.

The purpose of this study was to document the dynamics of HIV-1 subtypes in Scotland over a 6-year period. Viral RNA from all-new diagnoses was amplified by nested PCR and sequenced in the gag and/or env regions. Subtype was assigned by phylogenetic analysis, and aligned with demographic data including likely route and geographical origin of infection. We present data on 80% of all new diagnoses in Scotland between April 2000 and April 2006. Within the background of an expanding epidemic, subtype B predominates in men who have sex with men and intravenous drug users but there is a small but consistent number of UK-acquired infections in these risk groups caused by non-B subtypes. In heterosexuals, non-B subtypes acquired abroad, especially Africa, are still the largest group but again UK-acquired numbers are rising. The social and clinical significance of the spread of non-B subtypes in different ethnic and risk groups remains to be established.

Long-term comparison of rituximab treatment for refractory systemic lupus erythematosus and vasculitis: Remission, relapse, and re-treatment.

OBJECTIVE: Current treatments for systemic lupus erythematosus (SLE) and vasculitis contribute to mortality and incapacity and are only partially effective; thus, newer therapies are clearly needed. Depletion of B cells has led to disease control in patients with autoimmune disorders. We sought to assess the long-term efficacy and safety of a B cell-depleting therapy in patients with SLE and patients with vasculitis. METHODS: In a prospective study with a median followup of 24 months, 11 patients with active or refractory SLE and 11 patients with active or refractory antineutrophil cytoplasmic antibody-associated vasculitis (AAV) received a course of therapy with rituximab (an anti-CD20 monoclonal antibody) along with a single dose of intravenous cyclophosphamide. RESULTS: Remission followed rapid B cell depletion, with response rates of 100% among the 11 patients with SLE (6 patients had a complete response, and 5 patients had a partial response) and 91% among the 11 patients with AAV (9 patients had a complete response, and 1 patient had partial remission). A renal response occurred in all 6 patients with lupus nephritis. Clinical improvement was accompanied by significant reductions in the daily dose of prednisolone. Relapse occurred in 64% of the patients with SLE and in 60% of those with AAV. B cell return preceded relapse in the majority of patients, and further treatment with rituximab proved effective. IgG and IgM levels were maintained in the normal range. The incidence of infective complications was low; however, infusion reactions were common, and human antichimeric antibodies developed in 5 of 14 patients. CONCLUSION: B cell depletion offers the prospect of sustained disease remission and improved disease control combined with low toxicity in patients with active or refractory SLE or AAV. Relapse following treatment is common, but re-treatment is rapidly effective.

Mechanisms of apoptosis during reovirus infection.

Reovirus infection has proven to be an excellent experimental system for studying mechanisms of virus-induced pathogenesis. Reoviruses induce apoptosis in a wide variety of cultured cells in vitro and in target tissues in vivo, including the heart and central nervous system. In vivo, viral infection, tissue injury, and apoptosis colocalize, suggesting that apoptosis is a critical mechanism by which disease is triggered in the host. This review examines the mechanisms of reovirus-induced apoptosis and investigates the possibility that inhibition of apoptosis may provide a novel strategy for limiting virus-induced tissue damage following infection.

Attributions of control and seropositivity among Latinos: examining the predictive utility of the locus of control construct.

This investigation explored the utility of the health locus of control construct in predicting the mental health quality of life (MHQOL) ratings of 72 Latinos living with HIV/AIDS. After controlling for patient CD4 count, viral load, time since diagnosis, Physical Health Quality of Life and acculturative status, Powerful Others Locus of Control beliefs accounted for a significant increment of the variance in Mental Health Quality of Life. In a similar model, Internal Locus of Control failed to predict MHQOL. Discussion and implications highlight how cultural considerations may broaden investigations of health among diverse, minority populations.

HIV-1 subtype in Scotland: the establishment of a national surveillance system.

Historically, subtype B viruses in men who have sex with men (MSM) and injecting drug users (IDU) dominated the HIV epidemic in the United Kingdom, whereas non-B heterosexual infections dominate globally. Heterosexual contact is now the most common route of transmission in the United Kingdom. Here we monitor HIV subtype in Scotland, and link it to origin of infection. HIV-1 sequence was generated from new diagnoses and the subtype thus obtained linked with demographic data. Virus was subtyped from 80% (137/171) of all new diagnoses in Scotland. Of 58 individuals infected by heterosexual contact, 74% (43) harboured non-B viruses, contrasting with 7% (5/68) of those infected by IDU or MSM. Eighty-four per cent of non-Bs (46/55) were probably acquired outside the United Kingdom, but nine individuals probably acquired their non-B infection in the United Kingdom. Non-B subtypes of HIV-1 predominate in recently diagnosed, heterosexually acquired infections in Scotland and are present in all risk groups, even those with no exposure outside the United Kingdom.

Intrapartum epidural catheter migration: a comparative study of three dressing applications.

We compared three types of catheter fixation application for their ability to minimize the incidence and magnitude of epidural catheter movement during labour. Patients were randomized to have their epidural catheter secured by a Tegaderm dressing (group T; n = 35), a Tegaderm dressing plus filter-shoulder fixation (group F; n = 39), or a Niko Epi-Fix dressing (group N; n = 37). The length of catheter visible at the patient's skin surface was recorded (to the nearest 0.5 cm) after insertion and before removal; the difference was defined as 'catheter movement'. Outward movement of the catheter was greatest when a Niko Epi-Fix was used (P < 0.01). Concerning minimization of displacement of the epidural catheter per se, only a Tegaderm dressing with additional filter-shoulder fixation proved more effective than using a Niko Epi-Fix dressing (P < 0.05).

Prevention and management of hypotension during spinal anaesthesia for elective Caesarean section: a survey of practice.

Hypotension during obstetric spinal anaesthesia has traditionally been managed by such measures as fluid preloading, positioning of the patient and the use of vasoconstrictors. However, studies and reports have regularly appeared in the literature disputing the value of conventional management, in particular, the fluid preload. With this in mind, we surveyed UK consultant obstetric anaesthetists to determine current practice in this area. Of the 558 respondents, 486 (87.1%) stated that they routinely give a fluid preload. The fluid chosen by 405 (83.3%) of the preloaders was Hartmann's solution and the usual volume, chosen by 194 (39.9%), was 1000 ml. A simple left lateral position was preferred by 221 respondents (39.6%) overall and in the treatment of hypotension, ephedrine was the sole vasoconstrictor selected by 531 (95.2%). Heavy bupivacaine 0.5% was the local anaesthetic chosen by 545 (97.7%) and 407 (72.9%) respondents indicated the use of additional spinal drugs.

Protein kinase C and intracellular calcium are required for amphetamine-mediated dopamine release via the norepinephrine transporter in undifferentiated PC12 cells.

The role of protein kinase C and intracellular Ca(2+) on amphetamine-mediated dopamine release through the norepinephrine plasmalemmal transporter in undifferentiated PC12 cells was investigated. The selective protein kinase C inhibitor chelerythrine completely inhibited endogenous dopamine release elicited by 1 microM amphetamine. Direct activation of protein kinase C increased dopamine release in a Ca(2+)-insensitive, imipramine-sensitive manner and the release was not additive with amphetamine. Exocytosis was not involved since these events were not altered by either deletion of extracellular Ca(2+) or reserpine pretreatment. Down-regulation of protein kinase C activity by long-term phorbol ester treatment resulted in a dramatic decrease in amphetamine-mediated dopamine release with no apparent effect on [(3)H]dopamine uptake. To more completely examine a role for Ca(2+), intracellular Ca(2+) was chelated in the cells. Depletion of intracellular Ca(2+) considerably decreased dopamine release in response to 1 microM amphetamine compared with vehicle-treated cells, but had no effect on the [(3)H]dopamine uptake. Thus, our results suggest that amphetamine-mediated dopamine release through the plasmalemmal norepinephrine transporter is highly dependent on protein kinase C activity and intracellular but not extracellular Ca(2+). Furthermore, protein kinase C and intracellular Ca(2+) appear to regulate [(3)H]dopamine inward transport and amphetamine-mediated outward transport of dopamine independently in PC12 cells.

Report on the development of a procedure to prevent placement of feeding tubes into the lungs using end-tidal CO2 measurements.

OBJECTIVE: To determine the accuracy of a technique using capnography to prevent inadvertent placement of small-bore feeding tubes and Salem sump tubes into the lungs. SETTING: Twelve-bed medical intensive care unit (MICU) in a 557-bed teaching hospital. PATIENTS: A total of 25 ventilated adult MICU patients were studied-5 in phase 1 and 20 in phase 2. DESIGN: Phase 1 tested the ability of the end-tidal CO2 (ETCO2) monitor to detect flow (and thus accurately detect CO2) through small-bore feeding tubes. A small-bore feeding tube, with stylet in place, was placed 5 cm through the top of the tracheostomy tube ventilator adapter in five consecutive patients. The distal end of the feeding tube was attached to the ETCO2 monitor. The ETCO2 level and waveform were assessed and recorded. Because CO2 waveforms were successfully detected, a convenience sample of 20 adult MICU patients who were having feeding tubes placed (13 Salem sump tubes, 7 small-bore feeding tubes) was then studied. The technique consisted of attaching the ETCO2 monitor to the tubes and observing the ETCO2 waveform throughout placement. RESULTS: The study hypothesis was supported. Of the seven small-bore feeding tubes tested, all were successfully placed on initial insertion. Placement was confirmed by absence of an ETCO2 waveform and by radiograph. Of the 13 Salem sump tubes, 9 were placed successfully on first attempt and confirmed by absence of CO2 and by air bolus and aspiration of stomach contents. ETCO2 waveforms were detected with insertion of four of the Salem sump tubes; the tubes were immediately withdrawn, and placement was reattempted until successful. CONCLUSIONS: The technique described is a simple, cost-effective method of assuring accurate gastric tube placement in critically ill patients.

Quantitative analysis of myocardial perfusion changes with transmyocardial laser revascularization.

Transmyocardial laser revascularization (TLR) is a technique of creating left ventricular transmural channels in patients with refractory angina. We aimed to measure perfusion changes quantitatively using technetium-99m methoxyisobutyl isonitrile. Perfusion scans were performed on 94 TLRs and in 94 control patients at rest and during exercise at assessment, and 3-, 6-, and 12-month follow-up. A serial set of scans allowed direct comparison of each patient over all visits. Bull's-eyes were divided into 5 anatomic regions and a 20-region model. Severity values were calculated for rest, stress, and each cardiac region using a threshold of 1 for analysis. Higher scores indicated greater severity of ischemia and lower perfusion. At 3-month follow-up, the severity was significantly worse during TLR than in control patients both during stress (0.172 +/- 0.003 and 0.161 +/- 0.003, respectively, p = 0.007) and at rest (0.170 +/- 0.003 and 0.158 +/- 0.003, respectively, p = 0.002). At 6 months, severity during stress was 0.176 +/- 0.003 with TLR and 0.162 +/- 0.003 in controls (p = 0.001), with no significant difference at rest. At 12 months, there was no significant difference between TLR and control groups at stress and rest. Regional severity deteriorates during TLR compared with control patients anteriorly (p = 0.001, p = 0.0016, p = 0.005 at 3, 6, and 12 months), apically (p = 0.005, p = 0.0046, p = 0.032, respectively), and laterally (p <0.0001, p = 0.001, p = 0.002, respectively). An apparent improvement is observed in the inferoseptal region at 6- and 12-month follow-up-an area not lasered. Thus, TLR appears to produce deterioration in resting myocardial perfusion in lasered regions, and improvement in nonlasered regions, with no difference in exercise-induced myocardial ischemia compared with that in control patients.

The weaning continuum use of Acute Physiology and Chronic Health Evaluation III, Burns Wean Assessment Program, Therapeutic Intervention Scoring System, and Wean Index scores to establish stages of weaning.

OBJECTIVE: To determine whether four stages of weaning (acute, prewean, wean, and outcome) could be identified by using clinical instruments designed to quantify severity of illness, patient stability, or weaning readiness. The instruments used were the Acute Physiology and Chronic Health Evaluation (APACHE III), the Therapeutic Intervention Scoring System (TISS), the Burns Wean Assessment Program (BWAP), and the Wean Index (WI). The stages were adapted from those proposed by the American Association of Critical Care Nurses Third National Study Group's Weaning Continuum Model. DESIGN: Prospective, convenience cohort. This study was part of a larger study designed to test an outcomes managed approach to weaning by using an outcomes manager and a clinical pathway. SETTING: University medical intensive care unit. PATIENTS: Adult patients requiring mechanical ventilation >3 days admitted to the medical intensive care unit between November 1994 and May 1995. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Scores for the APACHE III, TISS, BWAP, and WI were collected on 97 patients every other day until they weaned, were transferred, or died. Outcomes described for each stage of weaning were dated on the clinical pathway when achieved. Comments about patient stability and ventilator progress also were recorded along with a subjective determination of the stage of weaning. We used decision rules to identify time intervals for each stage of weaning and outcomes attained by stage. Finally, APACHE III, TISS, BWAP, and WI scores were placed in each stage by date for analysis. The APACHE III, TISS, and BWAP scores were able to differentiate the acute, prewean, and wean stages but not the outcome stage. CONCLUSIONS: By identifying distinct scores for each stage, we may be able to better explore appropriate interventions for the stages as well as predict weaning outcomes. Indices that include physiologic and respiratory factors can differentiate weaning stages, but respiratory factors alone cannot.