New criteria for positron emission tomographic diagnosis of brain glioma using 11C-methionine

The study was based on the data of positron emission tomography (PET) and L-[methyl]-[11C]-methionine used in 117 patients with suspected brain tumor. PET data on 74 patients with histologically verified cerebral tumors were analyzed in detail. New additional criteria for assessing PET scans, which formed the PET syndromes of astrocytomas, anaplastic astrocytomas, and glioblastomas. Operative and histological verification confirmed the high validity of the proposed criteria for defining the type of a tumor.     

Dietary fat, body weight, and cancer: contributions of studies in rodents to understanding these cancer risk factors in humans

Understanding diet and energy balance as risk factors for breast, colon, and other cancers requires information on the contribution of each factor and of interactions among factors to cancer risk. Rodent models for breast cancer provide extensive data on effects of dietary fat and calories, energy balance, body weight gain, and physical activity on tumor development. Analyses of the combined data from many studies have shown clearly that quality and quantity of dietary fat and energy balance contribute independently to increased mammary gland tumorigenesis. These findings were seen in female rats fed diets high in fat (35-40% of calories) compared to rats fed control diets, with approximately 10% of calories as fat (Fay and Freedman, 1997, Breast Cancer Res. Treat. 46, 215-223). The methods used permit comparison of experimental and epidemiological data, and they may be useful in extrapolating between species and developing public health recommendations. In addition to the contributions of lifetime-diet composition, intake, energy balance, and physical activity to cancer risk, there are questions about the timing and duration of alterations in these factors and about the "dose-response" characteristics of cancer risk to the factors. Endocrine mechanisms may be significant in mammary gland tumor risk, but experimental and epidemiological data indicate that cancers at other sites, such as colon and liver, also are influenced by the factors listed. Other diet and lifestyle factors that influence energy, or specifically fat, metabolism may also affect risk for cancers that are promoted by increased intake of fat and calories. Studies of separate and interactive effects of dietary fat, black tea, weight gain, and mammary gland tumorigenesis (Rogers, et al, 1998, Carcinogenesis 19, 1269-1273) have been analyzed. Using adjustment of carcinogenesis endpoints for body weight, tumor burden, and latency, they were found to be related to weight gain within treatment groups in 2 of 3 experiments.      

Behavioural effects of glutamate receptor agonists in morphine-dependent rats

Glutamate receptors are implicated in the development and expression of drug dependence. Substantial experimental evidence suggests that antagonists acting at the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors attenuate the severity of opioid withdrawal. However, it is less clear whether opioid withdrawal can be potentiated by agonists of glutamate receptors. The present study evaluated the behavioural effects of various agonists of glutamate receptors, as well as a nitric oxide (NO) donor, in morphine-dependent rats trained to discriminate 0.1 mg/kg of naloxone from saline. None of the following drugs produced appreciable levels of naloxone-like responding (substitution tests) or potentiated the discriminative stimulus effects of naloxone: NMDA (3-56 mg/kg), glycine (100-1000 mg/kg), glutamate (1000-3000 mg/kg), kainate (0.3-3 mg/kg), isosorbide dinitrate (30-300 mg/kg). Nevertheless, expression of some morphine withdrawal-like somatic and behavioural signs ('wet-dog'-like shaking, scream on touch, ptosis, tremor, chewing, weight loss) was facilitated by NMDA, glycine, and isosorbide dinitrate. These results suggest that, compared to somatic symptoms, subjective effects of opioid withdrawal (as reflected by discriminative stimulus effects) are not mimicked by direct activation of glutamate receptors.     

Successful pregnancy in transfusion-dependent thalassaemia

Successful pregnancy in a transfusion-dependent thalassaemic patient receiving subcutaneous desferrixaomine is reported. This is the first such case to be described.     

Hypoaldosteronism in three sibs due to 18-dehydrogenase deficiency

Three sibs all presented in the early neonatal period with a salt-losing syndrome. The salt-losing form of congenital adrenal hyperplasia was diagnosed and appropriate treatment with glucocorticosteroids, mineralocorticosteroids, and additional dietary salt started. Although early life was maintained with difficulty, with age all 3 children required decreasing amounts of replacement steroids to maintain normal plasma electrolyte balance. They were reinvestigated at the ages of 15 years and 8 years (twins), when cortisol synthesis and metabolism proved normal, but aldosterone synthesis was blocked by deficiency of 18-dehydrogenase. Rational treatment of these cases of a salt-losing syndrome in which aldosterone synthesis alone is blocked due to lack of the enzyme 18-dehydrogenase requires the administration of a mineralocorticosteroid drug only. Since deoxycorticosterone (acetate or pivalate) requires intramuscular administration, as life-long therapy oral fludrocortisone is preferable. Although fludrocortisone has glucocorticoid activity, the "hydrocortisone equivalent" effect of the small dosage used was unlikely to inhibit either pituitary corticotrophin or growth hormone production.     

Biomarkers of periodontal inflammation in the Australian adult population

Background:  Several inflammatory biomarkers are implicated in the pathogenesis of periodontitis including interleukin-1β (IL-1β) and C-reactive protein (CRP). This study investigated the presence of these factors in gingival crevicular fluid (GCF) and their relationship to clinical and social determinants of periodontitis in the Australian population.
Methods:  Equal numbers of periodontitis cases and non-cases were sampled during oral epidemiologic examination in the National Survey of Adult Oral Health. GCF was sampled from four sites where probing pocket depth (PPD) and recession were recorded. From these, IL-1β and CRP were quantified by ELISA and the log amount of GCF IL-1β (pg) per person and the proportion of adults with detectable CRP was computed.
Results:  Periodontitis cases (n = 511) had significantly higher levels of IL-1β and CRP than non-cases (n = 562). PPD, clinical attachment loss, plaque and gingivitis indices were positively associated with elevated levels of both biomarkers. Levels of both were positively associated with age, low socio-economic position and non-Australian birth.
Conclusions:  The presence of IL-1β and CRP in GCF are associated with periodontal disease parameters within the Australian population. The levels of both biomarkers are influenced by age, education and eligibility for public dental care.     

雷米普利和氯沙坦对动脉粥样硬化早期形成的影响

目的 :研究雷米普利和氯沙坦对动脉粥样硬化 (atherosclerosis,AS)早期形成的影响。方法 :将 4 4只金黄地鼠随机分为 5组 ,分别给常规饲料 (对照组 )、高脂饲料 (含 10 %椰子油和 0 .0 5 %胆固醇 )、高脂饲料加雷米普利 (2mg·kg 1)、高脂饲料加氯沙坦 (10mg·kg 1)和高脂饲料加雷米普利 (2mg·kg 1)与氯沙坦 (10mg·kg 1)处理12周 ,测定血压、血脂、AS斑块面积和肝组织中胆固醇含量的变化。结果 :数据表明雷米普利和氯沙坦不论是单独应用还是联合应用均能有效降低平均动脉压 (P <0 .0 0 1)和肝组织中胆固醇的含量 ,雷米普利能显著降低血浆中甘油三酯的水平 (P <0 .0 5 ) ,结果还显示雷米普利与氯沙坦联合应用能提升血浆中高密度脂蛋白 (P <0 .0 5 ) ,各药物处理组的AS斑块面积有不同程度降低但无统计学意义。结论 :雷米普利与氯沙坦具有一定的抑制AS形成作用 ,其机制可能与降低血压和改变脂代谢有关。     

Alterations in synaptic curvature in the dentate gyrus following induction of long-term potentiation,long-term depression,and treatment with the N-methyl-d-aspartate receptor antagonist CPP

Alterations in curvature of the post synaptic density (PSD) and apposition zone (AZ), are believed to play an important role in determining synaptic efficacy. In the present study we have examined curvature of PSDs and AZs 24 h following homosynaptic long-term potentiation (LTP), and heterosynaptic long-term depression (LTD) in vivo, in awake adult rats. High frequency stimulation (HFS) applied to the medial perforant path to the dentate gyrus induced LTP while HFS stimulation of the lateral perforant path induced LTD in the middle molecular layer of the dentate gyrus (DG). Curvature changes were analysed in this area using three dimensional (3-D) reconstructions of electron microscope images of ultrathin serial sections. Very large and significant changes in 3-D measurements of AZ and PSD curvature occurred 24 h following both LTP and LTD, with a flattening of the normal concavity of mushroom spine heads and a change to convexity for thin spines. An N-methyl-d-aspartate (NMDA) receptor antagonist CPP (3-[(R)-2-Carboxypiperazin-4-yl]-propyl-1-phosphonic acid) blocked the changes in curvature of mushroom and thin spine PSDs and apposition zones, actually increasing the concavity of mushroom spines as the spine engulfed the presynaptic bouton. In order to establish whether these changes resulted from the effect of the NMDA antagonist or from its coincidence with synaptic activation during testing we examined the effects of CPP alone on PSD and apposition zone curvature. It was found that CPP alone also caused a small decrease in curvature of both PSD and apposition zone of mushroom and thin spines.