保存7天单采血小板的体外研究

本项研究的目的是确定单采血小板可允许保存的条件,包括容积、血小板成分的含量和特殊血小板成分保存袋内的血小板总量。材料和方法 本研究用单采机(COBE Spectra LRS Turbo,version 7,Gambro BCT,Denver,CO)从自愿献血者采集血小板成分,献血者符合 FDA和 AABB 献血标准,并在献血小板成分之前 7天内,没有服用改变血小板成分作用的药物和抗生素。控制每袋血小板成分的浓度和容积,以检测这些变量。悬浮在血浆中的血小板成分保存在特制的PVC合成的塑料袋中,枸椽酸钠抗凝,在22℃温控的恒温箱中震荡8天。     

Receptor tyrosine kinase stimulates cell-matrix adhesion by phosphatidylinositol 3 kinase and phospholipase C-gamma 1 pathways

Receptor tyrosine kinases are known to be important in growth and differentiation. We have recently found that c-kit, the tyrosine kinase receptor for steel factor, also regulates cell-matrix adhesion. Because Steel factor helps regulate cell migration and localization, this may be an important biologic function. Integrin adhesiveness is regulated within minutes by c-kit. The signaling pathways for tyrosine kinase stimulation of integrin adhesiveness and their relation to pathways that regulate growth and differentiation over much longer time periods remain uncharacterized. We have studied the effector pathways by which receptor tyrosine kinases regulate cell-matrix adhesion using wild-type and mutant forms of the platelet-derived growth factor (PDGF) receptor, which is closely related to c-kit. The PDGF receptor expressed in mast cells is as potent as c-kit in stimulating adhesion to fibronectin. We show that induction of adhesion is regulated through two independent pathways of phosphatidylinositol 3 kinase (PI3K) and phospholipase C- gamma 1 (PLC gamma)-protein kinase C by elimination of autophosphorylation sites required for activation of PI3K and PLC gamma or in combination with downregulation of protein kinase C or wortmannin. By contrast, a receptor mutated in both the PI3K and PLC gamma association sites can still stimulate mast cell growth, indicating a crucial role of these effector molecules in regulating adhesion rather than cell growth.     

A case of maple syrup urine disease misdiagnosed as Tetanus neonatorum on admission

A case of Maple Syrup Urine Disease (MSUD) is presented with clinical signs and symptoms on admission resembling neonatal tetanus. Diagnosis had to be differentiated between MSUD and other metabolic disorders and neonatal infections (especially neonatal tetanus because of severe opisthotonos) and generalized seizures of the patient. Early diagnosis of the MSUD patient is very important for effective therapy and better long-term prognosis as well as genetic counselling and prenatal diagnosis for future pregnancies.     

Facet joint arthrography in lumbar spondylolysis: anatomic basis for spread of contrast medium

Facet arthrograms in patients with lumbar spondylolyses show spread of contrast medium through pars interarticularis defects into the adjacent ipsilateral facet joint space and across the midline into the contralateral joint space. Transverse and sagittal sections of facet joints from 141 postmortem lumbar spines were studied. Five examples of spondylolysis were found. Anatomic studies of the relationship of the joint recesses to the pars interarticularis demonstrated the basis for the patterns of spread of contrast medium observed radiographically in this and previous series. The pars interarticularis forms the only boundary between the inferior recess of one facet joint and the superior recess of the adjacent joint. Fracture through the pars interarticularis establishes communication between adjacent ipsilateral joints and opens a communication to the retrodural space, through which contrast medium can track to the contralateral joint.     

Complications experienced in the rehabilitation of zone I flexor tendon injuries with dynamic traction splinting

A retrospective review of all flexor tendon repairs done between January 1985 to June 1987 determined the complication rate with our method of rehabilitation. One hundred sixty-three flexor tendon lacerations in 83 patients were reviewed. Follow-up ranged from 6 to 42 months. All patients participated in the same 12-week rehabilitation protocol. All patients had passive motion exercises of the interphalangeal joints in the first 2 weeks. We believe that passive stretching of zone I injuries during the first 2 weeks contributed to the zone I complication rate. Of the 20 patients with zone I tendon-to-tendon repairs, 7 patients had significant complications. The 35% complication rate found with zone I injuries has prompted us to modify our postoperative rehabilitation protocol in zone I injuries.     

Using Cluster Analysis to Examine Dietary Patterns: Nutrient Intakes, Gender, and Weight Status Differ Across Food Pattern Clusters

Objective This study explored the usefulness of cluster analysis in identifying food choice patterns of three groups of adults in relation to their energy intake.Design Food frequency data were converted to percentage of total energy from 38 food groups and entered into a cluster analysis procedure. Subjects in the emerging food group patterns were compared in terms of weight status, demographics, and the nutrition composition of their usual diet.Setting Data were collected as part of three studies in two US metropolitan areas using identical protocols. Participants were university employees (103 women and 99 men) who volunteered for a reliability study of health behavior questionnaires and moderately obese volunteers (223 women and 101 men) to two weight-loss studies who were recruited by newspaper advertisements.Statistical analysis performed Subjects were clustered according to food energy sources using the FASTCLUS procedure in the Statistical Analysis System. One-way analysis of variance and χ² analysis were then performed to compare the weight status, nutrient intakes, and demographics of the food patterns.Results Six food pattern clusters were identified. Subjects in the two clusters associated with high consumption of pastry and meat had significantly higher fat intakes (P=.0001). Subjects in two other clusters, those associated with high intake of skim milk and a broad distribution of energy sources had significantly higher micronutrient levels (P=.0001). Body mass index and the distribution of gender were also significantly different across clusters.Conclusions The success of cluster analysis in identifying dietary exposure categories with unique demographic and nutritional correlates suggests that the approach may be useful in epidemiologic studies that examine conditions such as obesity, and in the design of nutrition interventions. J Am Diet Assoc. 1997:97:272–279.     

Carnitine deficiency: a possible cause of gastrointestinal dysmotility

An infant with delayed development and peripheral myopathy, nourished on a soy-based liquid diet deficient in carnitine, had gastrointestinal dysmotility manifested by postprandial vomiting, oral drooling, delayed gastric emptying and infrequent bowel movements. Oesophageal manometry showed a reduced lower oesophageal sphincter pressure for age with abnormal distal motility. Serum carnitine concentration was 9.9 mumol l-1. After dietary supplementation of carnitine the gastrointestinal symptoms resolved, oesophageal manometry returned to normal, and serum carnitine increased to 37.2 mumol l-1. Dietary carnitine deficiency in infancy may be a cause of smooth muscle dysmotility of the gastrointestinal tract.     

Paranasal sinus hemorrhage: evaluation with MR imaging

Computed tomography (CT) and magnetic resonance (MR) imaging were performed in ten patients with paranasal sinus hemorrhage after trauma. Acute or subacute hemorrhage was detected on MR images by using T1- and T2-weighted imaging to identify the chemical state of the blood and to differentiate blood from mucosal thickening and sinus effusion. Surgical proof of intrasinus hemorrhage was obtained in only two cases. Displaced fractures, associated cerebral contusions, and traumatic encephalocele were well shown on MR imaging. Nondisplaced and minimally displaced fractures were better evaluated with CT.     

On the use of absorbing discs to sample mucosal surface liquids

A common technique to sample airway mucosal 'surface' liquids is with absorbing discs of filter paper. The present study examined the efficacy of this technique by analysing tracheal liquids of control and capsaicin (0.1 nmol)-exposed guinea-pig airways. Mucosal fluids, obtained by topically applied discs or by a specific lavage procedure, and tracheal tissue were sampled. The animals had received FITC-dextran (MW 70 kDa) intravenously and this specific plasma tracer was analysed in the sampled material. Under control conditions significantly more FITC-dextran was found in the discs than in the tracheal lavage fluids (P less than 0.001) despite the fact that the lavaged mucosal surface was much larger than that covered by the discs. Capsaicin significantly increased the content of FITC-dextran in all fluids sampled as well as in the airway tissue. In all cases concentrations of FITC-dextran in the disc fluids did not differ much from that in the tissue samples. These data suggest that absorbing discs severely disturb the epithelial-barrier function and sample subepithelial fluid and solutes including macromolecules. As demonstrated in this study by the elevated content of a plasma tracer molecule an inflammatory process may, nevertheless, be traced in the mixture of surface and tissue fluids that is sampled by the discs.     

Changes in body composition during 12 months after discontinuation of growth hormone therapy in young adults with growth hormone deficiency from childhood

Little is known about the velocity of changes in body composition after discontinuation of GH therapy at final height. The aim of this study was to describe the changes of fat distribution in male and female GH deficient young adults during the first year after discontinuation of GH therapy. Ten Dutch GH deficient young adults who had reached final height were retested and confirmed to be still GH deficient. These preliminary results demonstrate that the greatest gain in subcutaneous fat, measured by skinfold thickness, was observed in the first 3 months after GH withdrawal. Intra-abdominal fat was measured by CT scan at 0 and 12 months study time. The mean gain in intra-abdominal fat after 12 months was dramatically high (48%). We conclude that the subcutaneous and intra-abdominal fat mass increased dramatically in young GH deficient Dutch adults with GH deficiency, after discontinuation of therapy, especially in the first three months. This indicates that GH therapy should be restarted as soon as possible, after reconfirming the diagnosis of GH deficiency in adults. This will reduce the risk for these patients of diseases associated with overweight, such as cardiovascular diseases.