Randomized Controlled Trial of a Cohesive Eight-Week Evolution Unit That Incorporates Molecular Genetics and Principles of the Next Generation Science Standards.

In response to calls for curricular materials that integrate molecular genetics and evolution and adhere to the K-12 Next Generation Science Standards (NGSS), the Genetic Science Learning Center (GSLC) at the University of Utah has developed and tested the "Evolution: DNA and the Unity of Life" curricular unit for high school biology. The free, 8-week unit illuminates the underlying role of molecular genetics in evolution while providing scaffolded opportunities to engage in making arguments from evidence and analyzing and interpreting data.  We used a randomized controlled trial design to compare student learning when using the new unit with a condition in which teachers used their typical (NGSS-friendly) units with no molecular genetics. Results from nationwide testing with 38 teachers (19 per condition) and their 2269 students revealed that students who used the GSLC curriculum had significantly greater pre/post gain scores in their understanding of evolution than students in the comparison condition; the effect size was moderate. Further, teacher implementation data suggest that students in the treatment condition had more opportunities to engage in argumentation from evidence and have in-class discussions than students in the comparison classes. We consider study implications for the secondary and postsecondary science education community.

Coronary spasm and cardiac arrest from carcinoid crisis during laser bronchoscopy.

Bronchoscopic manipulation of an endobronchial carcinoid can precipitate a carcinoid crisis. Coronary artery spasm is an uncommon manifestation of carcinoid crisis, and has never been reported as a complication of flexible bronchoscopy. We report a case of a 10-year-old girl who developed coronary artery spasm and cardiac arrest during neodymiumyttrium aluminum garnet (Nd-YAG) laser photoresection of an endobronchial carcinoid. Recognition of this unusual presentation of a carcinoid crisis is important as the treatment approach differs from standard resuscitation protocols.

Effect of cranial surgery and brain tumor size on emergence from anesthesia.

BACKGROUND: Knowing which neurosurgical patients are at risk for delayed awakening may lead to better utilization of intensive care resources and avoid the risk and cost of pharmacologic reversal and diagnostic tests. METHODS: The authors compared anesthetic emergence from complex spinal surgery (spine; n = 47) with that from craniotomy for supratentorial nonfrontal (n = 22), frontal (n = 34), or posterior fossa tumor (n = 28). A further comparison involved patients with small versus large (diameter > 30 mm, mass effect) tumors. The standardized anesthetic regimen consisted of induction with 2-4 mg/kg-1 thiopental and 1-2 micrograms/kg-1 sufentanil, followed by maintenance with nitrous oxide, 0.2-0.5 micrograms.kg-1.h-1 sufentanil and < or = 0.5% isoflurane. Sufentanil administration was terminated on dural or spinal muscle closure, isoflurane during skin closure, and nitrous oxide during dressing application. After discontinuing nitrous oxide, a minineurologic examination was performed every 15 min for 1 h, then hourly for 4 h and at 24 h. RESULTS: Craniotomy patients performed less well than spinal surgery patients on the minineurologic examination 15 and 30 min after discontinuing nitrous oxide. At 15 min, fewer patients with large (vs. small) tumors were oriented to time (58% vs. 87%; P < 0.01) or place (67% vs. 90%; P < 0.01). Forty-two percent of patients with large tumors still had an abnormal minineurologic examination score versus 15% of patients with small tumors. At 30 min, these values were 28% and 8%, respectively (P < 0.05). Seventy-one percent of patients with large tumors were oriented to time compared to 97% for small lesions (P < 0.01). Emergence from anesthesia was similar for spinal surgery patients and patients with small brain tumors. CONCLUSION: Patients undergoing craniotomy for large intracranial mass lesions awaken more slowly than patients after spinal surgery or craniotomy for small brain tumor.

Effect of cocaine on the contracture response to 1% halothane in patients undergoing diagnostic muscle biopsy for malignant hyperthermia.

Two case reports have cited the recreational use of cocaine as possible trigger of a malignant hyperthermia (MH) crisis. We evaluated whether toxic concentrations of cocaine altered the in vitro muscle response to halothane during contracture tests for MH. Twenty-two patients were studied. Muscle biopsies were obtained and first tested for MH susceptibility with 3% halothane and caffeine contracture testing. Ten patients were diagnosed as MH-susceptible and 12 as MH non-susceptible, in accordance with the North American Malignant Hyperthermia Group protocol. Then, muscle strips were exposed to 1% halothane in the presence and absence of 0.1 mmol.L-1 cocaine. Cocaine alone did not affect baseline muscle tension in either group. With 1% halothane, MH non-susceptible muscle showed no contracture with or without cocaine. In contrast, in the presence of 1% halothane, MH-susceptible muscle showed either no change in contracture (six patients), an increase (two patients), or a decrease (two patients) when exposed to cocaine. However, the overall effect of cocaine on muscle contracture in the presence of 1% halothane was insignificant in both groups. We conclude that cocaine, even at toxic levels, does not have a direct effect on skeletal muscle contractility and thus is safe for MH-susceptible patients.

Portable anesthesia transport system.

Medical procedures that require general anesthesia outside of the traditional operating room setting have become commonplace. This paper describes a portable inhalational anesthesia machine developed for use in these outlying areas within the hospital. The device combines the basic components of vaporizer, oxygen analyzer, oxygen flow-meter, disposable carbon dioxide absorber and oxygen flush valve into a small package that may be carried with one hand. The unit may be used as a tabletop anesthesia machine or may be attached to a patient transport bed by means of a dedicated stand.

Fiber-type specific caffeine sensitivities in normal human skinned muscle fibers.

Caffeine sensitivity was studied in chemically skinned muscle fibers from vastus lateralis muscle obtained by biopsy during reconstructive knee surgery from 15 otherwise healthy young individuals. Muscle fiber type was determined by contracture occurring in strontium (slow-oxidative, type I fiber) or calcium (both type I and type II, fast glycolytic fiber) solutions and in several fibers after contracture testing by ATPase enzyme histochemistry. Caffeine sensitivity (mean +/- SD), defined as the threshold concentration inducing more than 10% of the maximal tension obtained with a calcium 3 x 10(-5) mM solution was 2.7 +/- 1.3 mM in 37 type I fibers, whereas it was 6.9 +/- 2.4 mM in 61 type II fibers. A paired t test showed a significantly increased sensitivity to caffeine in type I fibers (P less than 0.001) in 13 individuals in whom the two fiber types were identified. The mean (+/- SD) difference between type I and type II fibers was 4.1 +/- 1.9 mM. Type I fibers contracted with greater tension in response to the increasing concentration of caffeine than did type II fibers (P less than 0.05). These skinned fiber studies showed significantly different caffeine sensitivities between human type I and type II muscle fibers, as previously shown in animal muscles. The findings that human type I muscle fibers have higher caffeine sensitivity than type II muscle fibers should be helpful for the interpretation of the in vitro contracture test done in muscle strips containing type I and type II fibers in varying proportions.

Effect of etomidate on the electroencephalogram of patients with epilepsy.

Etomidate was given intravenously to 12 epileptic patients undergoing craniotomy for surgical removal of their seizure focus. Electroencephalograms were recorded by means of subdural electrodes. Nine of the 12 patients showed an increase in epileptiform activity. In six of the nine patients, the activity was marked.