Feedback delays and relaxation expectancies in EMG biofeedback

The use of noncontingent feedback controls in studies of the efficacy and process of electromyographic (EMG) biofeedback may yield results confounded by differential expectancies for relaxation. Furthermore, the role of expectancies in producing psychological and physical relaxation as well as reducing muscle activity is unclear. This study investigated the effects of feedback delays and induced relaxation expectancies on EMG activity and experienced relaxation. One hundred four non-clinical subjects participated in one auditory frontal EMG biofeedback training session. Subjects were assigned to one of four computerized feedback delay conditions (0.0037, 0.7493, 2.2481, 6.7444 s) and to one of two relaxation expectancy conditions (positive or negative). During 20 minutes of biofeedback training, all groups decreased frontal activity. Feedback delays interacted with training epochs in affecting EMG; the longest delay group reduced frontal activity more slowly than the shortest delay group during training. Positive relaxation expectancies produced greater experienced relaxation than did negative relaxation expectancies. Instrumental and expectancy factors in EMG biofeedback appear to operate independently of each other by reducing physiological activity and producing psychological relaxation respectively.This study was completed by the first author under the direction of the second author in partial fulfillment of the requirements for the Master of Arts degree. We gratefully acknowledge the computerization advice and assistance provided by Larry Wheeler, and the assistance in data collection provided by Dawn Dexter and Michael Winstanley.     

Effects of intravenous infusions of prostaglandin D2 in man

Prostaglandin D₂ (PGD₂) was infused intravenously into normal male volunteers. Seven subjects received infusions of 16, 32, 64 ng/kg/min and six of these a further dose of 128 ng/kg/min. Each individual's maximum dose was limited by discomfort caused by intense facial flushing and nasal congestion. At these doses there was no significant effect on systolic or diastolic blood pressure nor on spirometric measurements. There was a small but statistically significant tachycardia at 64 and 128 ng/kg/min. Collagen- and adenosine diphosphate (ADP)-induced platele aggregation was not affected at any of the infusion rates. Infused PGD₂ is unlikely to be a useful antithrombotic agent.     

Studies of the characterisation of prostanoid receptors: A proposed classification

Comparison of rank orders of agonist potency of the anturally occurring prostanoids. PGD₂, PGE₂, PGF₂α and PGI₂ as well as the stable TxA₂ mimetic, U-46619, on a range of smooth muscle preparations provides evidences evidence for the existence of distinct receptors for PGE₂. PGF₂α and TxA₂. Since others have provided evidence for the existence of distinct receptors for PGD₂ and PGI₂, we suggest that receptors exist for each of these naturally occurring 2-series prostanoids. Results obtained with two specific prostanoid receptor blocking drugs, SC-19220 and AH 19437, supported and extend these conclusions. SC-19220 selectively block some but not all PGE-sensitive receptors. While AH 19437 selectively blocks all U-46619/TxA₂-sensitive receptors. A nomenclature for prostanoid receptors is proposed,; in which each receptor is designated the letter P preceded by a letter signifying the most potent natural prostanoid agonist at than receptor, such that receptors sensitivity to PGs D₂, E₂, F₂α, I₂ and TxA₂ become DP-, EP-, FP- and TP- receptors respectively. Where some sub-division is required within a receptor group, e.g. EP-receptors (SC-19220-sensitive and SC-19220-insensitive), subcript numbers may be used such that these are EP₁ and EP₂ subtypes. The resulting scheme is a working hypothesis and its confirmation requires the development of potent selective prostanoid receptor blocking drugs for each postulated type.     

Lipoprotein lipase (LPL) deficiency: a new patient homozygote for the preponderant mutation Gly188Glu in the human LPL gene and review of reported mutations: 75 % are clustered in exons 5 and 6

We have investigated the lipoprotein lipase (LPL) gene of a 2-year-old patient presenting classical features of the familial LPL deficiency including undetectable LPL activity. DNA sequence analysis of exon 5 identified the patient as a homozygote for the Gly188Glu mutation, frequently involved in this disease. A review of cases of LPL deficiency with molecular study of the LPL gene showed a total number of 221 reported mutations involved in this disease. Gly188Glu was involved in 23.5 % of cases and 74.6 % of mutations were clustered in exons 5 and 6. Based on these observations, we propose a method of screening for mutations in this gene.     

Helminth eggs in animal coprolites from a Middle Pleistocene site in Europe

This paper reports on the discovery of dicrocoelid eggs in a coprolite collected in an archeological layer dated earlier than 550,000 yr BP (before present) from the Caune de l'Arago cave (Tautavel, Pyrénées-Orientales, France). It is the first trematode egg finding in an isolated coprolite from the Middle Pleistocene context.     

Non-occlusal dental microwear variability in a sample of Middle and Late Pleistocene human populations from Europe and the Near East

Non-occlusal, buccal tooth microwear variability has been studied in 68 fossil humans from Europe and the Near East. The microwear patterns observed suggest that a major shift in human dietary habits and food processing techniques might have taken place in the transition from the Middle to the Late Pleistocene populations. Differences in microwear density, average length, and orientation of striations indicate that Middle Pleistocene humans had more abrasive dietary habits than Late Pleistocene populations. Both dietary and cultural factors might be responsible for the differences observed. In addition, the Middle Paleolithic Neanderthal specimens studied show a highly heterogeneous pattern of microwear when compared to the other samples considered, which is inconsistent with a hypothesis of all Neanderthals having a strictly carnivorous diet. The high density of striations observed in the buccal surfaces of several Neanderthal teeth might be indicative of the inclusion of plant foods in their diet. The buccal microwear variability observed in the Neanderthals is compatible with an overall exploitation of both plant and meat foods on the basis of food availability. A preliminary analysis of the relationship between buccal microwear density and climatic conditions prevailing in Europe during the Late Pleistocene has been attempted. Cold climatic conditions, as indicated by oxygen isotope stage data, seem to be responsible for higher densities of microwear features, whereas warmer periods could correspond to a reduced pattern of scratch density. Such a relationship would be indicative of less abrasive dietary habits, perhaps more meat dependent, during warmer periods.