On the enhancement of creativity by alcohol: pharmacology or expectation?

Creative individuals may use psychoactive drugs to enhance their ability to produce creative works, but it is difficult to differentiate the pharmacological effects from other influences. Part of the problem is that creativity defies any simple definition, making it hard to determine when or how much creativity is evident. The other major obstacle is that life circumstances are confounded with the propensity to use drugs (including alcohol), so the causal relation of drugs to creativity is uncertain. We examined this question by an experiment in which subjects were asked to creatively combine pictures of wildflowers that were implicitly organized around a set of three dimensions: color, shape, and number. Pharmacological and expected effects of alcohol were dissociated in the experiment by using the balanced placebo design (BPD). The results showed no pharmacological effect of alcohol on the creative combinations that subjects produced. However, the novelty and structural recombination of the wildflower arrangements were enhanced when subjects thought they had consumed alcohol, whether or not they had actually done so. Implications for measuring creativity and the possible motivation to use drugs for creative effect are discussed.     

Observation of indium-vacancy and indium-hydrogen interactions in Hg1−xCdxTe

We have used a nuclear hyperfine technique, perturbed γγ angular correlation (PAC), to study the interactions between¹¹¹In and native defects and impurities in Hg_1−xCd_xTe. The PAC technique uses the quadrupole interaction of¹¹¹In with local electric field gradients to characterize the local environment of this donor dopant. We observed that when In was diffused into a bulk or thin film sample of Hg_1−xCd_xTe (x=0.21 and x=0.3) at 350°C and the sample was slow cooled, the In occupied sites with near-cubic symmetry, presumably the substitutional metal site. However, when the sample was quenched, a fraction of the In was incorporated into defects characterized by quadrupole interaction strengthsv _Q1 andv _Q2 and asymmetries of ν₁=ν₂=0.08. These defects are attributed to the trapping of a metal vacancy at a next-nearest neighbor site to the In atom. The introduction of hydrogen by boiling the samples in distilled water for >4h eliminated the previously observed PAC signals and created defects characterized byv _Q3=35 MHz, ν₃ <0.1 andv _Q4=MHz, ν₄ <0.1. These defects are attributed to the decoration of the In-V_Hg complex by a hydrogen atom. Hall effect measurements showed that hydrogenation increased the hole concentration in p-type quenched samples and even converted n-type indium-doped samples to p-type. A possible model for hydrogen incorporation which includes self-compensation by vacancy creation is suggested.     

Kinesin mutations cause motor neuron disease phenotypes by disrupting fast axonal transport in Drosophila

Previous work has shown that mutation of the gene that encodes the microtubule motor subunit kinesin heavy chain (Khc) in Drosophila inhibits neuronal sodium channel activity, action potentials and neurotransmitter secretion. These physiological defects cause progressive distal paralysis in larvae. To identify the cellular defects that cause these phenotypes, larval nerves were studied by light and electron microscopy. The axons of Khc mutants develop dramatic focal swellings along their lengths. The swellings are packed with fast axonal transport cargoes including vesicles, synaptic membrane proteins, mitochondria and prelysosomal organelles, but not with slow axonal transport cargoes such as cytoskeletal elements. Khc mutations also impair the development of larval motor axon terminals, causing dystrophic morphology and marked reductions in synaptic bouton numbers. These observations suggest that as the concentration of maternally provided wild-type KHC decreases, axonal organelles transported by kinesin periodically stall. This causes organelle jams that disrupt retrograde as well as anterograde fast axonal transport, leading to defective action potentials, dystrophic terminals, reduced transmitter secretion and progressive distal paralysis. These phenotypes parallel the pathologies of some vertebrate motor neuron diseases, including some forms of amyotrophic lateral sclerosis (ALS), and suggest that impaired fast axonal transport is a key element in these diseases.     

Genomic variation in Trypanosoma cruzi clonal cultures

Spontaneous changes in restriction DNA profiles and pulsed-field gel electrophoresis (PFGE) patterns, along with a concomitant loss of infectivity, were observed in infective clones of Trypanosoma cruzi strain Y either following a number of passages during the exponential growth phase of after subcloning in liver infusion tryptone (LIT) medium using as the probe a genomic fragment of the parasite (pMYP16), indicating naturally occurring rearrangements of DNA sequences. No variation could be detected when the genomic DNA was probed with conserved T. cruzi tubulin and actin genes. There was no correlation between such rearrangements and the life-cycle forms of the parasites, since trypomastigote forms showed the same karyotype and hybridization patterns as did epimastigote forms. The variations observed could be reverted and infectivity, recovered after inoculation of the parasites in newborn mice.     

Dental fear with and without blood-injection fear: implications for dental health and clinical practice

BACKGROUND: It has been suggested that the sympathetic nervous system might play an important role in the development of coronary artery spasm. However, no cardiac imaging modality has been able to demonstrate abnormal sympathetic innervation in patients with coronary artery spasm. The purpose of this study was to assess the presence and location of abnormal sympathetic innervation using iodine 123-metaiodobenzylguanidine (123I-MIBG) single photon emission computed tomography (SPECT) and to evaluate the clinical efficacy of 123I-MIBG SPECT as a noninvasive screening test in patients with coronary artery spasm. METHODS AND RESULTS: Coronary arteriography and a provocative test with intravenous administration of ergonovine maleate were performed in 26 patients (20 men, 6 women, mean age 48.2+/-12.0 years, range 20 to 67 years) who were suspected of having a coronary artery spasm. The subjects were divided into 2 groups: group 1 (n = 18) comprised subjects with a positive provocative test result, and group 2 (n = 8) comprised subjects with negative provocative test results. Ten healthy subjects served as controls. No abnormal MIBG uptake was observed in the control subjects. Abnormal sympathetic nervous innervation using 123I-MIBG SPECT was observed either as a reduced uptake or a defective pattern in the perfused areas in 13 of the 18 regions supplied by vessels of ergonovine-induced vasospasm. Normal sympathetic innervation, as evidenced by normal 123I-MIBG uptake, was noted in all of the 60 segments of normal vessel territories. Reduced uptake of 123I-MIBG was not detected in the perfused areas of 5 vasospasm-induced vessels (perfusion territory of left anterior descending coronary artery [LAD] and the right coronary artery [RCA] in 2 and 3 patients, respectively). The sensitivity and specificity of 123I-MIBG for detection of coronary artery spasm were 72.2% (95% confidence interval [CI] 55% to 89%) and 100%, respectively. The positive predictive and negative predictive values were 100% and 92.3% (95% CI 91% to 93%), respectively. CONCLUSION: 123I-MIBG SPECT is a feasible method to evaluate noninvasively and localize the territories of coronary arteries with spasm. Invasive diagnostic coronary arteriography with ergonovine provocation test may be unnecessary for diagnosis of coronary artery spasm in patients with typical resting pain, negative exercise test or normal thallium perfusion scan results, but showing abnormalities in 123I-MIBG SPECT.     

Use of the green fluorescent protein to rapidly assess viability of E. coli in preserved solutions

E. coli strain HB101 was genetically engineered to a fluorescent phenotype by transformation with a plasmid containing complementary DNA for a green fluorescent protein. The level of fluorescence in the transformed strain was directly proportional to the number of viable cells. There was a rapid decrease in fluorescence when transformed cells were inoculated into lamivudine solutions containing ten different preservative formulations. The decrease in fluorescence correlated to a decrease in the number of viable cells, allowing the relative antimicrobial properties of each solution to be compared. This methods provides a simple, rapid (< 2 min/assay), and accurate means of determining the effects of antimicrobial solutions on the viability of E. coli.     

Critical pharmacologic management in the emergency department

PURPOSE: Starting from a status hypercoagulability previous to substitutive hip and knee surgery, the aim of this work was to investigate the influence of different osteoarthropatic pictures for which arthroplasty is indicated in the activation of the clotting cascade, rheumatoid arthritis (RA) being one of such pictures. PATIENTS AND METHODS: Of 79 patients suitable for prosthetic surgery of hip (53) and knee (26), the preoperative values of several markers, namely, D dimers (D-D), thrombin-antithrombin (TAT) complex, and F1 + 2 prothrombin fragment (F1 + F2) were assessed by enzymoimmunoasay. The mean age of the patients was 65.5 years, and their sex distribution was 50 women and 29 men. The indications for arthroplasty were as follows: osteoarthrosis (62), aseptic necrosis (11), RA (9), articular gout (2), previous fracture (2), more than one diagnosis overlapped in some cases. The results attained were compared with a control group comprised of 33 subjects (16 women and 17 men) with mean age similar to the patient's group (68.06 years). RESULTS: The D-D values in the patients suitable for hip arthroplasty and the TAT values in patients suitable for both types of surgery were significantly higher than those found in the control group (p = 0.012 and 0.01, respectively). The preoperative TAT levels of the RA patients were significantly higher (p = 0.025) than those found in the patients with the other surgical indications. CONCLUSIONS: Previously to the performance of arthroplasty, the patients show hypercoagulative marker values higher than those of age-matched controls. The significant rising of TAT found in RA patients is concordant with the literature, and this fact makes it advisable to include RA among the pathologic situations associated with hypercoagulability, as this is a common indication for substitutive hip and knee surgery with high risk of venous thromboembolic disease.