Disruption of poly (ADP-ribose) polymerase (PARP) protects against stress-evoked immunocompromise

BACKGROUND

Chronic stress, mediated by adrenal hormones, is a major risk factor in the progression and outcome of human disease. While the secretion of adrenal hormones is known to be the primary endocrine mediator of stress-induced immunocompromise, the molecular mechanisms underlying the immunocompromise remain unspecified. Overproduction of the nuclear enzyme, poly (ADP-ribose) polymerase (PARP) has been implicated in the molecular pathway that leads to cell death by energy depletion following stress.

MATERIALS AND METHODS

Wild-type (WT) mice and mice with targeted disruption of the gene encoding PARP-1 (PARP-1 -/-) were subjected to 2 wk daily cold-water swim; splenocyte proliferation, anti-KLH IgG, and serum corticosterone concentrations were assessed. Additional mice of each genotype received daily i.p. injections of dexamethasone (DEX) (0.75 mg/kg) for 2 wk, and splenocyte proliferation and anti-KLH IgG were assessed.

RESULTS

Splenocyte proliferation and specific antibody concentrations of stressed WT mice were reduced by ~20% of their pre-stress levels. In contrast, PARP-1 -/- mice maintained normal cell-mediated and humoral immune function following enforced cold-water swim stress. PARP-1 -/- mice also failed to compromise immune function following DEX treatment, whereas WT mice displayed significant reductions of immune function following this treatment.

CONCLUSIONS

These results provide support for the involvement of PARP activation in immunological damage following physical stress. These results suggest that glucocorticoid-induced immunosuppression may require the activation of PARP in order for apoptosis of immune cells to take place. Taken together, these results suggest that therapies designed to inhibit PARP may prove valuable in the treatment of stress-related diseases.

Delayed gastric emptying in ventilated critically ill patients: measurement by 13 C-octanoic acid breath test

OBJECTIVE

To measure gastric emptying in ventilated critically ill patients with a new noninvasive breath test.

DESIGN

Single-center, open study.

SETTING

Combined medical and surgical intensive care unit of a university hospital.

SUBJECTS

Thirty unselected mechanically ventilated critically ill patients receiving gastric feeding and 22 healthy volunteers.

INTERVENTIONS

None.

PATIENTS

After 4 hrs without feeding, intragastric infusion of 100 mL of a liquid meal (Ensure) labeled with 100 microL 13C-octanoic acid. End-expiratory breath samples were collected into evacuated tubes from the respirator circuit every 5 mins for the first hour, then every 15 mins for 3 hrs. End-expiratory breath samples were also collected from volunteers studied supine after an overnight fast following an identical infusion via a nasogastric tube. Breath 13CO2 was measured with an isotope ratio mass spectrometer.

MEASUREMENTS AND MAIN RESULTS

Performance of the breath test posed no difficulty or interference with patient care. The CO2 level was >1% in 1297/1300 breath samples, indicating satisfactory end-expiratory timing. Data are median and interquartile range. Gastric emptying was slower in patients compared with volunteers: gastric emptying coefficient 2.93 (2.17-3.39) vs. 3.58 (3.18-3.79), p <.001 and gastric half emptying time, derived from the area under the 13CO2 curve, 155 min (130-220) vs. 133 min (120-145), p <.008. Fourteen of the 30 patients had a gastric emptying coefficient <95% of all volunteers and 11 had a gastric half emptying time longer than 95% of all volunteers. The Acute Physiology and Chronic Health Evaluation (APACHE II) score (median 22, range 13-43) either at admission or on the day of the study did not correlate with gastric emptying coefficient.

CONCLUSION

Gastric emptying of a calorie-dense liquid meal is slow in 40% to 45% of unselected mechanically ventilated patients in a combined medical and surgical intensive care unit. The 13C-octanoic acid breath test is a novel and useful bedside technique to measure gastric emptying in these patients.

Subfascial Endoscopic Perforator Surgery is More Cost-Effective Than Compression Bandaging for Healing Venous Ulcers

Objective:

To determine whether subfascial endoscopic perforator surgery (SEPS) is more cost-effective than compression bandaging for healing venous ulcers.

Design:

Cost analyses based on theoretical patients supposing the two methods are equally effective in healing venous ulcers.

Setting:

District hospital.

Patients:

A theoretical population of 200 patients with unilateral leg ulceration due to incompetent perforating veins.

Intervention:

The cost of SEPS was calculated based on outpatient visits, investigations and surgery including complications, with varying failure and re-ulceration rates. The cost of compression bandaging was estimated from published data and compared with that of SEPS.

Results:

The average cost per patient undergoing SEPS was £723. In 100 patients with an operative failure rate of 2% and a 10% re-ulceration rate, the cost increased to £818/patient in the first year (£16/ulcer-free week). A re-ulceration rate of 35% increased the cost to £23/ulcer-free week. However, the cost of compression bandage was £33/ulcer-free week using the same model, with healing rates of 50–70% at 20–40 weeks and a recurrence rate of 18–30% at 30–40 weeks.

Conclusion:

In a theoretical model SEPS was more cost-effective in healing venous ulcers due to incompetent perforators compared with compression bandaging.

Age-related changes in frontal and temporal lobe volumes in men: a magnetic resonance imaging study

BACKGROUND

Imaging and postmortem studies provide converging evidence that, beginning in adolescence, gray matter volume declines linearly until old age, while cerebrospinal fluid volumes are stable in adulthood (age 20-50 years). Given the fixed volume of the cranium in adulthood, it is surprising that most studies observe no white matter volume expansion after approximately age 20 years. We examined the effects of the aging process on the frontal and temporal lobes.

METHODS

Seventy healthy adult men aged 19 to 76 years underwent magnetic resonance imaging. Coronal images focused on the frontal and temporal lobes were acquired using pulse sequences that maximized gray vs white matter contrast. The volumes of total frontal and temporal lobes as well as the gray and white matter subcomponents were evaluated.

RESULTS

Age-related linear loss in gray matter volume in both frontal (r = -0.62, P<.001) and temporal (r = -0.48, P<.001) lobes was confirmed. However, the quadratic function best represented the relationship between age and white matter volume in the frontal (P<.001) and temporal (P<.001) lobes. Secondary analyses indicated that white matter volume increased until age 44 years for the frontal lobes and age 47 years for the temporal lobes and then declined.

CONCLUSIONS

The changes in white matter suggest that the adult brain is in a constant state of change roughly defined as periods of maturation continuing into the fifth decade of life followed by degeneration. Pathological states that interfere with such maturational processes could result in neurodevelopmental arrests in adulthood.

Behavioral and pharmacological treatment methods for pregnant smokers: issues for clinical practice

Active and passive exposure to tobacco smoke are the most serious and preventable causes of poor maternal, fetal, and infant outcomes in the United States. Unfortunately, the majority of pregnant smokers do not quit smoking before or during pregnancy or after childbirth. We describe a standardized behavioral counseling model and discuss issues to consider in recommending the use of pharmacotherapy during pregnancy. Although the Food and Drug Administration no longer classifies nicotine replacement therapy (NRT) as contraindicated during pregnancy, precautions should be carefully considered for use in this population. This paper provides a synopsis of the risks of exposure to tobacco smoke during pregnancy and the postpartum; estimates the population at risk and the potential for increased cessation if effective health education methods during pregnancy were routinely provided; presents a meta-analysis of "best practice" patient education methods for pregnant smokers; and estimates the number of pregnant heavy smokers who might be eligible for NRT. We suggest five issues for the physician to consider before recommending NRT medications to pregnant patients who are heavy smokers. The judicious use of NRT medications may significantly reduce harm to the infants of heavy smokers. More evidence derived from large population-based research, however, is needed to provide guidance to the physician about NRT eligibility, dose, scheduling, and effectiveness in clinical practice.

Planning and policy for emergency services: four fallacies, two problems and some possible solutions

This paper examines some of the misapprehensions that have often underpinned the planning of accident and emergency services in the UK. Accident and emergency (A&E) is not a homogenous group of activities and the different components that make up the service should be planned separately. This planning needs to be accompanied by some significant redesign to meet growing patient expectations. In particular, there is a major challenge for services to offer local access in an environment in which acute care is increasingly centralized.

Continuing Education for Nurses in Tianjin Municipality, the People's Republic of China

BACKGROUND

A descriptive survey examined continuing education experiences of hospital nurses working in Tianjin Municipality, the third largest municipality in The People's Republic of China.

METHOD

Fourteen hospitals and two hundred nurses were selected randomly.

RESULTS

Over two thirds of the nurses had attended continuing education events in the previous few years. Learning experiences included on-site and off-site workshops; associate degree courses; and teaching strategies of mostly lectures, films and videos. Major barriers discouraging nurses from participating included lack of time, cost, distance, and being denied permission to attend. Nurses working in rural and suburban hospitals reported less access to continuing education opportunities than nurses in urban hospitals. Ninety-six percent of respondents reported they had made changes in their clinical practice as a result of the continuing education activities.

CONCLUSION

Strategies to reduce barriers to continuing education and future research examining the impact of continuing nursing education on clinical practice in China need to be developed.

Factors associated with cane use among community dwelling older adults

Guided by the Theory of Planned Behavior (TPB), this study examined factors associated with cane use among community dwelling older adults. Data were collected in a cross-sectional survey of a convenience sample of 106 community residing older adults in Ottawa, Canada. Using a stepwise discriminant analysis, subjective norms, attitudes, and age surfaced as the key variables associated with cane use in this sample. The discriminant function accounted for 67% of the variance in cane use and correctly classified 91% of cases (Wilks's lambda = 0.33, lambda2 = 110.12, df = 3, p < 0.0001). The findings provide evidence for the utility of the TPB in its application to understanding cane use behaviors of older persons and have important implications for the design of theory-based fall prevention interventions to enhance the acceptance and effective use of mobility aids.

Increased CSF volumes are associated with diminished subjective responses to cocaine infusion

We evaluated the hypothesis that ventricular and cortical CSF volume increases are associated with reductions in the magnitude of euphoric effects produced by intravenous IV cocaine infusion in cocaine dependent (CD) individuals. Eleven CD patients participating in a cocaine-infusion study and eleven control subjects underwent magnetic resonance imaging (MRI). Two CSF regions of interest (lateral ventricles and frontal cortex CSF) and two comparison regions (third ventricle and posterior cortex CSF) were measured. Self-reported ratings of the intensity of euphoric response ("high") were obtained from the CD subjects at 3, 10, and 30 minutes after IV administration of cocaine. A significant negative correlation was observed between the volume of the lateral ventricles and subjective ratings of the "high" experienced at 3 minutes, but not at 10 and 30 minutes after cocaine infusion. In contrast, a significant negative correlation between frontal cortex CSF volume and the intensity of euphoric response was observed at 30 minutes after IV cocaine. No significant associations were observed between the volumes of the two comparison regions and any subjective ratings of "high." No significant volume differences were observed between the CD and control groups in any region. The results suggest larger lateral ventricular volumes are associated with a decrease in immediate euphoria while larger frontal cortex CSF volumes are associated with a decrease in the duration of the euphoria induced by cocaine infusion. The age-related brain volume reductions underlying the volume increase in these two CSF spaces may be the neurobiological basis of the age-related reduction in the rates of addiction.

Pre-eclampsia is associated with marked alterations in sleep architecture

STUDY OBJECTIVES

Pre-eclampsia is currently the predominant cause of maternal and fetal morbidity and mortality. Diurnal blood pressure variation is flattened or reversed in pre-eclampsia; however, sleep has not been extensively investigated in this disease. Our objective was therefore to study sleep architecture in this group of patients.

STUDY DESIGN

Full polysomnography using the Compumedics Sleepwatch System or Compumedics p-series.

SETTING

NA.

PATIENTS

25 pre-eclamptic patients and 17 primigravidas with normal pregnancies and no history of cardiovascular disease or sleep disorder. With the exception of one subject, all pre-eclamptics were taking clonidine (a known suppressant of rapid eye movement-REM-sleep) for control of their hypertension.

INTERVENTIONS

NA.

RESULTS

Pre-eclamptic subjects had markedly altered sleep architecture, with a markedly increased percentage of time spent in slow-wave sleep (SWS) (21 * 2% versus 43 * 3%, p<0.001). There was a longer latency to rapid eye movement (REM) sleep (92 * 11 mins vs. 205 * 23 mins in control and pre-eclamptic subjects, respectively, p<0.001) and reduced time spent in REM (18 * 1% and 10 * 2% in control and pre-eclamptic subjects, respectively, p<0.001).

CONCLUSIONS

While the increased REM latency and decreased REM time are most likely due to clonidine, this is unlikely to also account for the increased SWS. Two possible explanations for this include cerebral edema and release of cytokines, which are known to alter sleep structure.