Essential oils of three Baccharis species

The essential oils of the aerial parts of three Baccharis species ( B. articulata, B. myrtilloides, and B. rufescens) were examined by GC and GC/MS. The major constituents were for B. articulata: beta-caryophyllene (16.8%), trans-nerolidol (15.6%); for B. myrtilloides: germacrene D (9.5%) and for B. rufescens: limonene (14.4%) and trans-nerolidol (14.5%).     

Differential heart-rate responses to person in nervous and normal pointer dogs

Members of two behaviorally contrasting lines of purebred pointer dogs were tested during development at ages 3, 6, and 9 months for heart-rate response to the presence of and petting by a human. Dogs of the Nervous line, which show retreat, fearfulness, and freezing postures in the presence of humans and novel objects, exhibited at all ages a reduced heart rate with the person in the chamber and during petting. Dogs of the Normal line, which show friendliness and playfulness with humans and exploratory behavior toward novel objects, exhibited at 6 and 9 months an increased heart rate with the person in the chamber and a reduction of heart rate toward beseline during petting. Reciprocal crosses of the two lines clearly showed at 3 months the pattern characteristic of the male parent, while at 6 months the pattern for both hybrid types did not resemble the Nervous-line bradycardia pattern, but showed reduced aspects of the patterns of both lines. The data suggest a genetic explanation for markedly different physiologic effects of an emotion-provoking stimulus, which elicits what appears to be a negative emotional effect in one line and a positive emotional effect in the other line.This research was supported in part by the Veterans Administration Research Service and in part by the Marie Wilson Howells Memorial Fund of the Department of Psychiatry and Behavioral Sciences, University of Arkansas for Medical Sciences.     

Marijuana effects on immunity: suppression of human natural killer cell activity of delta-9-tetrahydrocannabinol

Delta-9-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, was tested for its ability to modulate human natural killer (NK) cell function. THC was toxic for peripheral blood lymphocytes at 20 micrograms/ml but not at 10 micrograms/ml or less. This component of marijuana also was inhibitory for NK activity against K562, a human tumor cell line at concentrations down to 5 micrograms/ml when pre-incubated with the effector cells. Suppression of NK function was dependent upon the concentration of THC and the length of time of pre-incubation but was independent of the ratio of effector to target cells. Prostaglandins were not involved in suppression of NK activity.     

Is there hardening of the heart during medical school?

PURPOSE: To determine whether vicarious empathy (i.e., to have a visceral empathic response, versus role-playing empathy) decreases, and whether students choosing specialties with greater patient contact maintain vicarious empathy better than do students choosing specialties with less patient contact. METHOD: The Balanced Emotional Empathy Scale was administered at the beginning of each academic year at the University of Arkansas for Medical Sciences for four classes, 2001-2004. Students also reported their gender and specialty choice. Specialty choice was classified as core (internal medicine, family medicine, obstetrics-gynecology, pediatrics, and psychiatry) or noncore (all other specialties). RESULTS: Vicarious empathy significantly decreased during medical education (P < .001), especially after the first and third years. Students choosing core careers had higher empathy than did those choosing noncore careers. Men choosing core careers initially had empathy exceeding population norms, but their empathy fell to be comparable with that of norms by the end of their third year. The empathy of men choosing noncore careers was comparable with that of norms. Women choosing core careers had empathy scores comparable with those of norms, but the scores of women choosing noncore careers fell below those of the norms by their second year. CONCLUSIONS: The findings suggest that undergraduate medical education may be a major determinant differentially affecting the vicarious empathy of students on the basis of gender and/or specialty choice. The greatest impact occurred in men who chose noncore specialties. The significant decrease in vicarious empathy is of concern, because empathy is crucial for a successful physician-patient relationship.     

ERbeta isoform expression in colorectal carcinoma: an in vivo and in vitro study of clinicopathological and molecular correlates

Colorectal carcinoma shows several sex-related differences with regard to incidence, response to chemotherapy and microsatellite instability. These differences may relate to differential expression of ERbeta1 (wild-type) as well as the truncated ERbeta2 and ERbeta5 splice variant isoforms, which have recently been detected in normal and malignant colorectal epithelium. This hypothesis was tested through the study of ERbeta isoform protein and/or mRNA expression amongst 91 primary colorectal carcinoma cases and 20 colorectal carcinoma cell lines. Study of the latter showed an absolute correlation between mRNA and protein expressions for ERbeta1 and ERbeta2. ERbeta1 and ERbeta2 protein expression was lost in 22% and 49%, respectively, of the primary colorectal carcinomas. By contrast, ERbeta5 expression was found in all primary colorectal carcinomas and all colorectal carcinoma cell lines studied. Lower ERbeta1 protein expression was associated with poorer differentiation, higher pT stage and absence of microsatellite instability. Higher ERbeta2 protein expression was associated with right-sided location and presence of lymph node metastases. Protein expression of ERbeta1 correlated positively with expression of the oestrogen-responsive protein trefoil factor 1 (TFF1). There was no correlation between ERbeta protein isoform expression and response to 5-fluorouracil therapy, tumour proliferation, or thymidylate synthase expression. These data suggest that ERbeta1 and/or ERbeta2 isoform expression may have prognostic value and may explain sex-related differences in microsatellite instability and colorectal carcinoma. The opposing associations shown by ERbeta1 and/or ERbeta2 in relation to colorectal carcinoma are in keeping with differential activities shown by the two isoforms.     

Antibody-mediated enhancement of Legionella pneumophila-induced interleukin 1 activity.

The ability of antibody specific for Legionella pneumophila to enhance the induction of interleukin 1 (IL-1) production by murine peritoneal, splenic, and pulmonary macrophages in response to the bacterium was examined. Two preparations of L. pneumophila were utilized, a formalin-killed whole-cell preparation and viable bacteria. We measured both secreted (sIL-1) and cell membrane-associated (mIL-1) activities after incubation of the macrophages with the bacterial preparations in the presence or absence of the antibody. Both bacterial preparations induced sIL-1 and mIL-1 activities in each of the macrophage populations tested. These activities were generally enhanced by pretreating the bacteria with antibody, with the greatest enhancing activity observed for the formalin-killed preparations at lower doses of bacteria.     

The effect of structural aberrations of the chromosomes on reproductive fitness in man

Methods are presented to estimate relative fitness of carriers as a function of fertility, survival, are generation time in pedigrees under incomplete ascertainment. A large sample of diverse chromosomal aberrations reveals significant effects on all three parameters, giving a relative fitness of .769 +/- .039. There is no significant shift in segregation frequency. Implications of these results for population dynamics of structural rearrangements are discussed. The following paper applies these methods to specific classes of aberrations.     

The Operation of Immunological Networks in Graves'' Disease

Association between Graves' disease and HLA--B8 has been previously documented, as have been associations between 1 gG heavy chain allotype markers (Gm). We found a significant increase in the phenotype fnb/fb (ie. positivity for fb) in patients with Graves' disease compared to controls, raising the possibility of allotypic restriction of thyroid stimulating antibodies thought to be causally related to the disease. The influence of fb on the susceptibility to Graves' disease was found to be independent of HLA--B8 status suggesting that the immunological network operated by the Histocompatibility-linked genes is independent of that centered around IgG allotypes. It is postulated that, whereas the former genes determine the level of helper T lymphocyte function in the production of thyroid stimulating antibodies in Graves' disease, a person who also happens to carry the Gm marker fb would be assured of the production of IgG antibodies with thyroid stimulatory activity.     

Dietary and mechanically induced rabbit iliac-femoral atherosclerotic lesions: a chemical and morphologic evaluation

The effect of combining chronic endothelial injury and intermittent meal feeding of a high and low cholesterol, coconut oil, peanut oil diet on plama lipid and lipoprotein content and on the formation of atherosclerotic lesions within the iliac-femoral artery of rabbits was studied. Alternate feeding of a 1 or 0.1% cholesterol, 3% coconut oil, 3% peanut oil diet for 3 to 14 weeks resulted in a 4- to 11-fold increase in plasma cholesterol with 59 to 79% of the plasma cholesterol eluting in a molecular weight fraction comparable to human low density lipoproteins (LDL). In the iliac-femoral artery, an atherosclerotic intimal lesion with an average cross-sectional area of 0.452 mm2 was present in 98% of the animals. The lesion was typically eccentric in location and contained both superficial- and deep-intimal lipid-filled monocyte-macrophages, extracellular lipid, smooth muscle cells, and extracellular connective tissue matrix. The relative percent lipid composition of the iliac-femoral lesion was 62% cholesteryl ester, 21% free cholesterol, and 17% phospholipid. Thus, we conclude that the combination of meal feeding a cholesterol/fat diet, dietary regimen and chronic mild endothelial injury in the rabbit results in (1) a diet-induced hypercholesterolemia in which LDL appear to be the predominant lipoprotein; and (2) a lesion within the iliac-femoral artery comparable in histologic and chemical composition to a human fatty streak.