朝藿素D的分离和结构

从朝鲜淫羊藿(Epimedium koreanum)地上部分分离得到一新黄酮成分(I)和一已知化合物(II)。经光谱解析,证明I的结构为5,7,3',4'-tetrahydroxy-5'-prenylflavone,命名为朝藿素D(epimedokoreanin D);II为2-hydroxy-3,4,6,7-tetramethoxy-9,10-dihydrophenanthren。     

Mechanisms of Acetaldehyde-Mediated Growth Inhibition: Delayed Cell Cycle Progression and Induction of Apoptosis

Chronic ethanol exposure has been associated with pleiotropic effects on cellular function in vivo and in vitro, including inhibition of growth. To date, it has been difficult to dissociate the primary effects of ethanol from the effects of ethanol metabolism, generation of acetaldehyde, and reducing equivalents. We have previously described the development of a Chinese hamster ovary cell line, A-10, which expresses a transfected murine-liver alcohol dehydrogenase. Cultures of these cells accumulate acetaldehyde due to the low level of aldehyde dehydrogenase. One noticeable effect of chronic acetaldehyde exposure, but not ethanol exposure, is the inhibition of cell growth. This study focuses on the mechanisms that underlie this growth inhibition. Our studies with the A-10 cell on the rates of [³H]thymidine incorporation and flow cytometry of asynchronous cultures indicated that acetaldehyde did not lead to arrest of the cell cycle in the G₁ phase as has been found in other models of ethanol exposure. Rather, we observed a generalized delay in cell cycle progression. However, the slower cell cycle did not account exclusively for the slower rates of cell accumulation. Chronic exposure to acetaldehyde also increased the rate of cell death. The increased rate of cell death was both cumulative and dose-dependent. The dead cells accumulated in the medium and were apoptotic. Apoptosis was confirmed using morphological criteria and quantitation of DNA fragmentation. These data lend additional support to the idea that chronic acetaldehyde exposure can affect the mechanisms that regulate cell division and the apoptotic program.     

Upper Gastrointestinal Hemorrhage Associated with Cutaneous Application of Diclofenac Gel

We present four cases of upper gastrointestinal hemorrhage associated with the cutaneous application of diclofenac (Voltaren Emulgel). The patients' ages ranged from 24 to 85 yr. Three of the patients had used the medication three times daily for at least 2 wk before the onset of bleeding. In two cases, the treatment was indicated for backache which, retrospectively, was attributable to a peptic ulcer. In those two patients, the hemorrhage was massive, requiring blood transfusions. Because systemic absorption of nonsteroidal anti-inflammatory drugs from topical formulations has been documented, caution should be exercised when prescribing these formulations to patients with a history of peptic ulcer.     

Characterization of a quantitative assay for the in vitro transformation of normal human diploid fibroblasts to anchorage independence by chemical carcinogens

We have characterized an assay for the quantitative measurement of the frequency of conversion to anchorage-independent growth of N-acetoxy-2-acetylaminofluorene-treated normal human diploid fibroblasts. We investigated the effects of the following parameters on the absolute number and on the frequency of anchorage-independent colonies scored: (a) the number of cells seeded per dish; (b) the type of posttreatment medium; (c) the number of population doublings allowed posttreatment prior to seeding in suspension; and (d) the carcinogen dose. The assay was linear over the range of 1.9 X 10(3) to 3.8 X 10(4) cells seeded per 6-mm dish for both total colonies scored and the induced frequency of anchorage-independent growth. The medium used posttreatment affected both the frequency and the kinetics of appearance of the anchorage-independent phenotype. The number of population doublings and the number of days allowed posttreatment prior to assaying for anchorage-independent growth potential also influenced the frequency of recovery of this phenotype. Under standardized conditions, the assay yielded a dose-response relationship for transformation to anchorage independence over the concentration range of 0 to 10 microM N-acetoxy-2-acetylaminofluorene.     

Intestinal microvascular exchange in the rat during luminal perfusion with formyl-methionyl-leucyl-phenylalanine

Formyl-methionyl-leucyl-phenylalanine (FMLP), a peptide released from bacteria in the gut lumen, is known to both attract and activate neutrophils. The aim of this study was to determine whether luminal perfusion with 1 microM FMLP alters microvascular permeability, blood flow, and neutrophil migration in the small intestine of control rats and rats treated with antineutrophil serum. Microvascular permeability to total plasma proteins was determined from an analysis of lymphatic protein fluxes. Myeloperoxidase activity was used as an index of tissue neutrophil count. Intestinal blood flow was measured using radiolabeled microspheres and the reference blood sample method. In control rats, luminal perfusion with FMLP caused significant increases in blood flow, lymph flow, lymph protein clearance, and microvascular permeability, but it did not alter tissue myeloperoxidase activity. In rats treated with antineutrophil serum, tissue myeloperoxidase levels were reduced by approximately 55%, and the FMLP-induced changes in lymph flow, lymph protein clearance, and microvascular permeability were significantly attenuated. In vitro experiments with isolated rat neutrophils revealed that 1 microM FMLP elicits significant chemotaxis and degranulation yet minimally enhances superoxide production. The results of this study indicate that peptides produced by microorganisms in the gut lumen can increase intestinal microvascular permeability. The FMLP-induced alterations in microvascular exchange appear to be mediated by activated neutrophils.     

The use of fibrin adhesive in the repair of chondral and osteochondral injuries

Fibrin adhesive proved to be useful in the reattachment of chondral and osteochondral fragments. Its use is based on sound biological principles. It offers a number of advantages over internal fixation; it causes no further damage to the cartilage, even small chondral fragments can be reattached and a second operation for the removal of metalwork is unnecessary. Its bonding strength provides only contact stability, so that immobilization in plaster for 3 weeks is always necessary. In the last 5 years we have used fibrin adhesive in 28 patients for the fixation of 39 chondral or osteochondral fragments. Of these, 26 cases were followed up for periods of 6 months to 5 years. Twelve patients were examined arthroscopically; 9 of them showed complete healing of the fragments, and only 3 slight localized degenerative changes. In 15 cases we were able to see radiological healing. All except two showed union of the fragments and restoration of the joint surface. In view of our results fibrin adhesive can be recommended for the operative management of cartilage injuries.     

CT in the early diagnosis of herpes simplex encephalitis

Herpes simplex is the most common cause of sporadic viral encephalitis. The recent development of specific antiviral chemotherapeutic agents offers new optimism for patients with this disorder if therapy is begun on or before the fifth day of the disease. Eight patients with herpes simplex encephalitis were studied by CT, and a characteristic but not pathognomonic pattern was observed. In each case a low density lesion was noted in the medial portion of the temporal lobe with extension into the Island of Reil. Sparing of the lenticular nucleus was observed in all cases. Mass effect and streaky linear enhancement after contrast administration was also seen. Unfortunately, the findings may be subtle or absent before the fifth day of disease, and thus CT scans must be examined with a high index of suspicion if the correct diagnosis is to be made at a time when therapy may prove useful. Hemorrhagic areas are rarely observed on CT in this disorder despite the frequent occurrence on pathologic studies. The full extent of involvement may not be appreciated on scans obtained during the first 10 days of the disease.     

Effectiveness of nonpenetrating trabeculectomy in aphakic patients with glaucoma

Nonpenetrating trabeculectomy was performed on 28 aphakic eyes consisting of 18 with chronic open-angle glaucoma and 10 with secondary and/or complicated glaucoma. The canal of Schlemm and the juxtacanalicular trabecular meshwork were excised for a length of 4 mm beneath a 6 mm x 6 mm scleral flap. At one year postoperatively, 72.0% of all patients were controlled, 24% required no antiglaucoma medications. However, 88% of chronic simple glaucoma patients were satisfactorily controlled. The mean follow-up period was 1.4 years. Minimal complications have been encountered to date. Nonpenetrating trabeculectomy may be valuable as an initial procedure in aphakic patients who require glaucoma filtration surgery.     

Priorities and indications of computed tomography in clinical practice

Summary Because of its technical capabilities, its rapidity and its non-invasive nature, computed tomography (CT) has given a new scope to neurological diagnosis and to the understanding of various aspects of neurological science. The availability of this test is determined by the patient load. If precise clinical indications are not considered, patients requiring CT the most may be denied immediate examination because less urgent cases may be occupying valuable diagnostic time. Moreover, the test is relatively expensive for the individual patient and for the community; this presents another facet of its use that should be taken into account.The technical limitations and clinical priorities to be considered when a physician is entertaining this test for a patient have been outlined. The indications have been divided into absolute and relative, according to the degree of clinical urgency. As a result, a priority guideline for diagnostic CT has been provided.Recipient of USDHS Teacher-Investigator Award 5KO 7NS 11061-04.