The effect of time of day on apnoea index in the sleeping rat

This study tested the hypothesis that apnoea index would be greater during daytime sleep than nighttime sleep in the rat. Electroencephalogram and electromyogram were monitored via biotelemetry implant and respiration was measured using whole body plethysmography in six male rats in two separate 34h recording sessions per animal. Apnoeas were classified as "spontaneous" or "post-sigh". Daily average spontaneous apnoea index was 35 times greater (p<0.0001) during rapid eye movement (REM) sleep than in non-REM (NREM) sleep. In contrast, daily average post-sigh apnoea index was not significantly greater in REM sleep than in non-REM (NREM) sleep (p=0.39). There was a greater post-sigh apnoea index during daytime REM than during nighttime REM (p=0.043) but REM-related spontaneous apnoea index was unaffected by time of day. There was no day to night difference in spontaneous apnoea index or post-sigh apnoea index during NREM sleep. Respiratory variability (coefficient of variation for breath duration and tidal volume) was not affected by time of day in REM or NREM sleep. We conclude that the circadian timing system has no effect on apnoea index during NREM sleep in the rat, but it may influence the propensity for post-sigh apnoea during REM sleep.     

Do therapists address ethnic and racial differences in cross-cultural psychotherapy?

Ethnic and racial differences between client and therapist affect therapy processes and outcomes, but little is known about the extent to which therapists have dialogues about their differences in therapy. A survey on this topic was completed by 689 APA-licensed psychologists with experience conducting cross-cultural therapy. Most psychologists reported having such discussions, but with less than half of their cross-ethnic/racial clients. Therapists and clients were equally likely to initiate discussions. Reasons for discussing differences varied greatly. Therapists consistently described themselves as comfortable with and skilled at these discussions, and reported that discussions facilitated therapy. Therapists who were female, older, nonminority, less experienced with diverse clients, and viewed training as an important factor were more likely to have discussions about differences. Results point to the need to better understand if, when, and how ethnic and racial differences should be addressed in therapy. (PsycINFO Database Record (c) 2011 APA, all rights reserved).     

In utero repair of gastroschisis in the sheep (Ovis aries) model

Objective

Gastroschisis is associated with inflammatory changes in the exposed bowel which leads to intestinal dysmotility after postnatal repair. The insult is a combined effect of amniotic fluid exposure and mechanical constriction. We hypothesized that in utero anatomic repair is possible in a sheep model, and that it may halt the inflammatory damage caused by both mechanisms.

Methods

Gastroschisis was surgically created in mid-gestation (day 75) in 8 sheep fetuses. On gestational day 100, 2 fetuses underwent open fetal gastroschisis repair, where the eviscerated bowel was returned to the peritoneal cavity, and the abdominal wall was primarily closed. All fetuses were harvested at 135 days of gestation.

Results

Six fetuses survived the initial operation, and both fetuses that underwent gastroschisis repair survived to term. At 100 and 135 days of gestation, the eviscerated bowel showed progressive signs of inflammation and peel development. The gross and microscopic inflammatory changes in the gastroschisis bowel at 100 days of gestation were completely resolved at term following in utero repair.

Conclusion

In utero anatomic repair of gastroschisis is possible in mid-gestation in the fetal lamb model, and it appears to ameliorate the inflammatory process.     

Measurement of limb volume: laser scanning versus volume displacement

BACKGROUND: Determining the prevalence and treatment success of surgical lymphedema requires accurate and reproducible measurement. A new method of measurement of limb volume is described. METHODS: A series of inanimate objects of known and unknown volume was measured using digital laser scanning and water displacement. A similar comparison was made with 10 human volunteers. Digital scanning was evaluated by comparison to the established method of water displacement, then to itself to determine reproducibility of measurement. RESULTS: (1) Objects of known volume: Laser scanning accurately measured the calculated volume but water displacement became less accurate as the size of the object increased. (2) Objects of unknown volume: As average volume increased, there was an increasing bias of underestimation of volume by the water displacement method. The coefficient of reproducibility of water displacement was 83.44 ml. In contrast, the reproducibility of the digital scanning method was 19.0 ml. (3) Human data: The mean difference between water displacement volume and laser scanning volume was 151.7 ml (SD +/- 189.5). The coefficient of reproducibility of water displacement was 450.8 ml whereas for laser scanning it was 174 ml. CONCLUSION: Laser scanning is an innovative method of measuring tissue volume that combines precision and reproducibility and may have clinical utility for measuring lymphedema.     

Early massive transfusion in trauma patients: Canadian single-centre retrospective cohort study

Purpose

To determine associations between red blood cell (RBC) transfusion and early and late clinical outcomes in massively transfused adult trauma patients.

Methods

A retrospective cohort study (1992–2001) including 260 patients receiving ≥10 RBC units ≤24 hr after admission to a university-affiliated trauma centre. We extracted demographic and clinical data and used multivariable regression to determine independent effects of RBC transfusion on clinical outcomes.

Results

Patients had a high (mean [standard deviation]) injury severity score (ISS) (42.5 [15.1]), a high admission sequential organ failure assessment (SOFA) score (8.4 [3.8]), and a high hospital mortality (58.5%). They received 38 (25–64) (median [interquartile range]) blood components within 48 hr, including 19 (14–28) RBC units. For 143 patients surviving ≥48 hr, the maximum SOFA score was associated with RBC units transfused before 48 hr (linear regression beta coefficient 0.075, P < 0.0001), lower nadir hemoglobin before 48 hr (0.034, P = 0.03), age (0.032, P = 0.015), and admission SOFA (0.59, P < 0.0001). The RBC units transfused by 48 hr were not associated with either hospital mortality (n = 35) among patients surviving ≥48 hr (independent predictors, age [logistic regression odds ratio (OR) 1.06, 95% confidence interval 1.03–1.10], ISS [OR 1.07, 1.02–1.13], and maximum SOFA score [OR 1.56, 1.27–1.93]) or 48-hr mortality (n = 117) (independent predictors, admission SOFA [1.65, 1.45–1.88] and later year of hospital admission [OR 1.15, 1.02–1.29]).

Conclusions

Hospital mortality is high among massively transfused trauma patients. Among early survivors, 48-hr RBC transfusion volume is associated with increased organ dysfunction, but not hospital mortality. Also, it is not associated with 48-hr mortality. Future research should continue to explore methods to improve hemostasis and minimize the need for RBC transfusion.     

Resolution of obstructive sleep apnea with epilepsy surgery? Expanding the relationship between sleep and epilepsy

Recent studies suggest a higher than expected prevalence of obstructive sleep apnea (OSA) in patients with refractory epilepsy. In some cases, treatment of OSA improves seizure control. We report a case in which clinically significant OSA disappeared after left frontal lobe resection that produced a near seizure free state. This occurred in the absence of the usual factors, such as weight or medication change or variation in polysomnography (PSG) recording methodology, that often confound the comparison of sequential PSGs over time. Our patient underwent PSG with 18-channel EEG recording pre- and postoperatively using standardized scoring techniques. Baseline testing revealed an apnea-hypopnea index (AHI) of 24 with severe oxygen desaturations reaching a nadir of 62%. Postoperative testing found both the AHI and oxygen saturation normalized as well as a marked reduction in spike rate. We hypothesize that the pathophysiology of OSA in patients with epilepsy may be impacted by frequent, extensive interictal epileptiform discharges (IEDs) and/or seizures altering upper airway control during sleep.     

Development of an anti-porcine CD34 monoclonal antibody that identifies hematopoietic stem cells

OBJECTIVES: The isolation of porcine hematopoietic stem cells (HSC) would be an important step toward development of porcine-to-human chimerism for induction of tolerance in clinical xenotransplantation. CD34 is a common marker of HSC and has not been developed as a marker in pigs. In this study we have generated and characterized a monoclonal antibody (mAb) that identifies porcine CD34 on a subset of porcine bone marrow (BM) stem/progenitor cells. METHODS: The porcine CD34 gene was cloned and a recombinant protein produced. An anti-porcine CD34 mAb was produced that could detect both the recombinant protein and a subset of porcine BM cells. The CD34(+) cells were phenotyped by lineage and HSC associated markers. Furthermore, the CD34(+) cells were analyzed by colony-forming unit (CFU) assay. RESULTS: Two splice variants of the porcine CD34 gene were cloned and a recombinant protein produced for mAb production. The mAb developed can detect both the recombinant protein and the native CD34 protein on a range of pig tissues, including BM. This subset of BM cells was negative for hematopoietic lineage makers, including CD3, CD14, and CD21 and positive for other known porcine HSC markers, including CD90, CD172a, histocompatibility complex (MHC) class I, and MHC class II. Moreover, the CD34(+) BM cells were enriched for multilineage progenitor cells as determined by CFU assay. CONCLUSIONS: Similar to human and mouse CD34, pig CD34 detects a subset of BM progenitor cells. This mAb will now provide a means for isolating porcine CD34(+) cells to be further analyzed for HSC activity and to assess their potential to develop pig-to-human chimeras to induce xenograft tolerance.