中药贝母类的研究——ⅩⅦ.贝母鳞叶上表皮显微观察

本文对浙贝母Fritillaria thunbergii Miq.等20种贝母的鳞叶上(内)表皮进行了显微观察,发现种间在表皮细胞形状、大小和垂周壁部位角质栓(cuticular peg)的形状,大小和排列等方面有一定区别,可作为新的鉴别依据。全文除描述外,列出检索表,并附主要特征图。     

Intravenous digital subtraction renal angiography: use in screening for renovascular hypertension

Intravenous digital subtraction renal angiography (DSRA) has been compared with conventional angiography only in small, selected series of hypertensive patients. The authors prospectively examined with intravenous DSRA 94 patients at increased risk for renovascular hypertension and compared these studies with conventional angiography. A stenosis of at least one main renal artery was identified with intravenous DSRA in 22 patients and confirmed in 20 patients. No significant stenoses were seen with conventional angiography in any of the 64 patients in whom lesions were not seen with intravenous DSRA. Since inadequate DSRA studies were considered positive for renal artery stenosis, the sensitivity of intravenous DSRA was 100% (25 of 25); specificity, 93% (64 of 69); positive predictive value, 83% (25 of 30); and negative predictive value, 100% (64 of 64). The authors conclude that intravenous DSRA is a sensitive test for identifying stenosis of the main renal arteries and is appropriate to use as a screening test among patients at increased risk for renovascular hypertension.     

Focal Adhesion Kinase Is Important for Fluid Shear Stress‐Induced Mechanotransduction in Osteoblasts

Mechanical loading of bone is important for maintenance of bone mass and structural stability of the skeleton. When bone is mechanically loaded, movement of fluid within the spaces surrounding bone cells generates fluid shear stress (FSS) that stimulates osteoblasts, resulting in enhanced anabolic activity. The mechanisms by which osteoblasts convert the external stimulation of FSS into biochemical changes, a process known as mechanotransduction, remain poorly understood. Focal adhesions are prime candidates for transducing external stimuli. Focal adhesion kinase (FAK), a nonreceptor tyrosine kinase found in focal adhesions, may play a key role in mechanotransduction, although its function has not been directly examined in osteoblasts. We examined the role of FAK in osteoblast mechanotransduction using short interfering RNA (siRNA), overexpression of a dominant negative FAK, and FAK^?/? osteoblasts to disrupt FAK function in calvarial osteoblasts. Osteoblasts were subjected to varying periods oscillatory fluid flow (OFF) from 5 min to 4 h, and several physiologically important readouts of mechanotransduction were analyzed including: extracellular signal‐related kinase 1/2 phosphorylation, upregulation of c‐fos, cyclooxygenase‐2, and osteopontin, and release of prostaglandin E₂. Osteoblasts with disrupted FAK signaling exhibited severely impaired mechanical responses in all endpoints examined. These data indicate the importance of FAK for both short and long periods of FSS‐induced mechanotransduction in osteoblasts.     

Blood donation leads to a decrease in natural killer cell activity: a study in normal blood donors and cancer patients

Transfusion-induced immunosuppression has long been known to be beneficial for organ transplantation patients, but recent retrospective studies suggest that blood transfusions may be detrimental for patients with cancer. If autologous blood is used to avoid immunosuppression, the assumption is that the procedure, involving blood donation, is immunologically neutral. In the present study, this assumption was evaluated by monitoring 33 normal blood donors and 16 colorectal cancer patients before and after donation of 1 (500 mL) and 2 units of blood, respectively. The cancer patients belonged to the autologous arm of a randomized trial in which the effects of allogeneic versus autologous blood on cancer prognosis were studied. The patients donated 2 units of blood with an interval of 3 to 4 days between donations. Flow cytometric analysis revealed that blood donation by normal donors and cancer patients had no effect on the proportion of B, T, and natural killer (NK) cells. Only the total number of lymphocytes was significantly decreased in the normal donors on Day 12 after donation. Blood donation had no significant effect on T-cell function assessed by phytohemagglutinin stimulation in normal donors or in cancer patients donating 2 units of blood. A significant depression of NK cell function (88% and 74% of predonation levels) was observed in normal donors on Days 2 and 5 after donation; on Day 12, the activity was again normal. Colorectal cancer patients had a significantly depressed NK cell activity (54% of predonation activity) on Day 12 after the first donation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Normalization of enhanced hepatic gluconeogenesis by the antiglucocorticoid RU 38486 in acutely uraemic rats

Hepatic amino acid uptake, urea and glucose production are increased in acute uraemia. It has been shown that this metabolic pattern is mediated by glucocorticoids. Accordingly, the administration of the antiglucocorticoid RU 38486 to acutely uraemic rats resulted in a reduction of serum urea-N and glucose levels. To clarify whether this effect is due to a reduction in hepatic gluconeogenesis we examined the effect of the antiglucocorticoid RU 38486 on urea and glucose formation in isolated hepatocytes from sham-operated (SHAM) and bilaterally nephrectomized (BNX) rats receiving RU 38486 or the vehicle only. Hepatic glucose production in BNX rats was considerably increased from Na-pyruvate (+79%), alanine (+174%), glutamine (+158%), and serine (+87%) compared with SHAM animals. Concomitantly, hepatic urea formation was also enhanced from amino acid substrates in acutely uraemic rats. When uraemic animals were treated with RU 38486, glucose production from amino acids and Na-pyruvate was reduced to the range of SHAM animals or even lower. This effect could not be demonstrated in SHAM-operated controls. A comparable decrement in hepatic urea production was observed in BNX rats treated with the antiglucocorticoid. Thus, glucocorticoids appear to play a key role in the abnormal hepatic urea and glucose production of acutely uraemic rats.     

Nationwide survey of home transfusion practices

BACKGROUND: Limited information exists on home transfusion practices. STUDY DESIGN AND METHODS: In 1995, a survey requesting data for 1994 was sent to 1273 American Association of Blood Banks (AABB) institutional members and 113 non-AABB home health care agencies that provide out-of-hospital transfusions. RESULTS: Of 943 respondents, 102 provide blood to a home transfusion program, 37 provide blood and run a home transfusion program, and 13 run a home transfusion program only, for a total of 152 (16%) with some involvement in home blood transfusions. Most of the 50 respondents with a home transfusion program are licensed by their state and accredited by the Joint Commission on Accreditation of Healthcare Organizations. All respondents have written policies for home transfusion, and 90 percent require a signed informed-consent document before initiating transfusions in the home. Most have policies requiring that there be a second adult and a telephone in the home, that the home be deemed safe for transfusion, that the patient's physician be readily available, and that the patient have had prior transfusions. The most common component issued by the blood providers was red cells, followed by platelets. White cell-reduced components were always provided by 36 percent of respondents. The most common patient diagnosis was cancer. Home transfusions were provided primarily by registered nurses. Only 14 percent of respondents indicated that the medical director of the blood bank is responsible for approving a patient for home transfusion. A posttransfusion visit is performed by 46 percent of respondents. CONCLUSION: Although most facilities have policies for the administration of home transfusions, there remains marked heterogeneity among blood providers and transfusionists regarding home transfusion practices.     

Feasibility of intravenous gemcitabine and an intraperitoneal platinum agent in the treatment of ovarian cancer

The goal of this study is to determine the feasibility of intravenous gemcitabine and an intraperitoneal platinum agent in the treatment of patients with ovarian cancer. We performed a retrospective chart review of patients with primary, persistent or recurrent ovarian cancer, who received intravenous gemcitabine and an intraperitoneal platinum agent. Patients received gemcitabine (750 mg/m2) intravenous on days 1 and 8 and cisplatin (100 or 60 mg/m2) intraperitoneal on day 1 every 21 - 28 days. An alternate regimen was composed of gemcitabine (750 mg/m2) intravenous and carboplatin (AUC 5) intraperitoneal on day 1 every 21 days. Dose reductions occurred at the discretion of the prescribing physician.Intravenous gemcitabine and an intraperitoneal platinum agent were administered to 12 patients with advanced primary or recurrent ovarian cancer. Myelosuppression was the most common toxicity. Grade 3 or 4 thrombocytopenia, neutropenia and anemia occurred in 7, 8 and 2 patients respectively. Dose reductions were required in 7 of 12 patients. 10 of 12 patients received 6 cycles of the regimen. Treatment was discontinued prior to 6 cycles in 2 of 12 patients secondary to progression in one case and to grade 4 neutropenia and thrombocytopenia in another.The combination of intravenous gemcitabine and an intraperitoneal platinum agent appears to be a feasible regimen in patients with ovarian cancer. The most common toxicity was myelosuppression, which resulted in dose reductions in almost half of the patients.