EFFECTS OF NALOXONE, GLYCYRRHIZIC ACID, DEXAMETHASONE AND DEOXYCORTICOSTERONE IN REPETITIVE STRESS

1. The present study examined the effect of naloxone (NAL), glycyrrhizic acid (GCA), deoxycorticosterone (DOC) and dexamethasone (DEX) on daily repeated 2 h chronic restrained stress (RS) on the locomotor activity (LA) of rats tested in the open field arena to elucidate the possible roles of opioids, glucocorticoids and mineralocorticoids in response to stress. 2. Intact and adrenalectomized (ADX) rats were either injected with 0.1 mL of NAL (0.32 microgram/100 g BW), 2.4 mg/kg DOC or 120 micrograms/kg DEX or had 1.0 mg/mL GCA dissolved in their drinking water or normal saline (for the ADX group) dissolved in their drinking water. 3. In intact groups, treatment with NAL completely blocked the stress response and treatment with GCA, DOC and DEX partially prevented the stress response. Adaptation occurred on either days 4, 5, 6 or 7 for intact rats treated with DEX, DOC, GCA or control rats, respectively. All ADX control rats died following the first 2 h RS. Adrenalectomized rats treated with DEX or DOC adapted later compared with intact rats, while rats given either GCA or NAL were unable to block or adapt to chronic RS. 4. These findings demonstrate that the stress response is primarily mediated by endogenous opioids, in that it is blocked by NAL. Both mineralocorticoids and glucocorticoids, which can act centrally to inhibit endorphins, partially blocked the stress response. The effect of GCA in intact rats was similar to that of both DEX and DOC in intact rats. Adrenalectomized rats treated with GCA (despite their lack of endogenous corticosterone) showed a stress response that was significantly different from the other ADX groups, implying that GCA had effects independent of endogenous corticosterone.     

SHORT- AND LONG-TERM EFFECTS OF GLYCYRRHIZIC ACID IN REPETITIVE STRESS

1. This study was carried out to determine the effect of short-term and long-term ingestion of glycyrrhizic acid on the response to 2 h of restraint stress by measuring locomotor activity and plasma corticosterone levels. 2. Male Sprague-Dawley rats were randomly assigned into four groups, each group having eight rats. Group 1 (control) was given ordinary tap water, while groups 2 (short term), 3 and 4 (both long term) were given tap water containing 1 mg/mL glycyrrhizic acid to drink for 10 days, 4 weeks and 9 weeks, respectively. All the rats were subjected to 2 h of restraint stress and the locomotor activity assessed using an activity test in an open field arena followed by blood sampling to determine the plasma corticosterone level. These procedures were repeated daily for 14 days. 3. The basal locomotor activity scores for rats given glycyrrhizic acid for 10 days or 4 weeks were similar to those of controls; however, that of the rats treated long term with glycyrrhizic acid was significantly lower (21.0 +/- 3.0 squares crossed; P < 0.0005). Following the first period of restraint stress there was a highly significant decrease in locomotor activity, which remained significantly lower until the seventh and subsequent periods, indicating an adaptation to the repeated stress had occurred. Although the decrease in locomotor activity was partially blocked and adaptation to repetitive stress was enhanced in the rats given glycyrrhizic acid for 10 days, this was not seen in rats treated with glycyrrhizic acid for 4 or 9 weeks. The corticosterone levels in control rats were significantly elevated for 4-5 days following the exposure to repetitive stress but decreased gradually from day 7 onwards. However, both short- and long-term glycyrrhizic acid-treated rats had higher plasma corticosterone levels than the controls (P < 0.05). 4. In conclusion, repetitive restraint stress caused decreased locomotor activity associated with increased plasma corticosterone levels, both of which, in normal rats, decreased with adaptation to stress. The stress response was partially blocked and adaptation enhanced in rats given glycyrrhizic acid for 10 days, but not in rats given glycyrrhizic acid for 4 and 9 weeks. Glycyrrhizic acid ingestion caused high plasma corticosterone.     

Does prophylactic sotalol and magnesium decrease the incidence of atrial fibrillation following coronary artery bypass surgery: a propensity-matched analysis

Background  

Atrial fibrillation can occur in up to 40% of patients undergoing coronary surgery.     

急性重度毒蕈中毒性肝炎抢救成功1例

1　病例报告　男 ,16岁 .误食毒蕈后出现恶心 ,呕吐伴有腹痛、腹泻 4d,每日大便 4～ 12次 ,为稀水便 ,有心慌、气短、发热 ,在当地医院以“毒蕈中毒”救治 ,症状无缓解 ,为进一步治疗于 2 0 0 0 - 0 8- 31转入我院 .查体 :T37.8℃ ,P110次·min-1 ,R18次·min-1 ,BP14/ 9k Pa.全身皮肤黄染 ,巩膜重度黄染 ,心肺无阳性体征 .腹平坦 ,上腹部有压痛 ,肌紧张及反跳痛 ,肝脾未触及 ,肝区有叩击痛 ,移动性浊音阳性 .入院后患者出现烦躁 ,意识不清 ,心率时快时慢 ,血压不稳定 .肝功 :T- BIL 2 5 4.1μmol· L-1 ,D- BIL 16 9.5 μmol· L-1 …     

An antibody that facilitates hematopoietic engraftment recognizes CD44

Pretreatment of recipients with the monoclonal antibody (MoAb) S5 facilitates engraftment of bone marrow from mismatched, unrelated donors in the canine transplantation model. In the direct comparisons reported here, the S5 glycoprotein (gp) was found to have structural homology to CD44 that in humans has been implicated in adhesive interactions of one type of effector cell, the lymphocyte. The S5 antigen and gp90Hermes-1 exhibited codistribution on canine peripheral blood cells. Both S5 and Hermes-1 (anti-CD44) MoAbs recognized 90-Kd species in radioimmune precipitations of 125I surface-labeled canine peripheral blood lymphocytes and bone marrow cells. Competitive antibody binding experiments showed that the epitope detected by S5 was distinct from that bound by Hermes-1 but overlapped with those defined by two other known anti-CD44 reagents, IM7 and Hutch-1. Sequential immunoprecipitation with S5 and Hermes-1 indicated that the two antibodies recognize the same or overlapping subsets of membrane gps. Tryptic digestion of S5 and anti-CD44 immunoprecipitates generated two major iodinated peptides of 27 and 35 Kd in both cases, a further indication of structural homology. Similarly, after N-glycanase digestion, S5 and CD44 immunoprecipitates were resolved to a single 68- Kd species. These findings suggest that CD44-mediated adhesive events may affect the fate of transplanted hematopoietic cells. The previous implications of this gp in T-lymphocyte activation and lymphocyte adhesion to endothelium thus provide useful paradigms to analyze its function in the bone marrow transplant setting.     

The use of opioids in neonates. A retrospective study of 933 cases

This is a retrospective study on the use of postoperative opioids in neonates admitted to the surgical intensive care unit at Great Ormond Street over a 5-year period (1980-84). A total of 131 (14%) babies received opioids out of 933 neonates admitted to the unit. The use of opioids increased from 9.7% to 27.2% of admitted cases during the survey period. Postoperative ventilation of the lungs was necessary in 240 (25.7%) cases and 88 (36.6%) of these were given opioids. Four babies initially failed to wean from controlled ventilation as a result of opioid induced respiratory depression. A total of 51 (7.35%) spontaneously breathing neonates received opioids and seven (13.7%) of these developed apnoea or respiratory failure thought to be induced by opioids. The administration of opioids by nurses occurred most frequently in the late evening and early hours of the morning, when medical cover is at its lowest level.     

A Brief, Intensive, Clinically Focused Geriatrics Course During the Third Year of Medical School

During the next several decades, the aging of the "baby boom" generation in the United States will result in a dramatic increase in the number of patients aged 65 and older seeking medical care, but current projections suggest that the shortage of geriatrics-trained specialists will only worsen during this time period. As a result, the care of elderly patients will largely fall to other types of physicians. Consequently, it is imperative that medical school training include exposure to the basic skills needed to care safely for older adults. This goal is challenging, because the number of geriatric medicine faculty in most academic medical centers is small, and multiple other medical specialties are also vying for time in a busy medical school curriculum. Whether a 3-day course conducted during the third year of medical school could teach basic principles of geriatric medicine in a time- and manpower-effective manner was explored. It was found that even this brief exposure to geriatrics could have meaningful effects on student knowledge of and comfort with geriatrics.