Patterns of cerebral injury and clinical presentation in the vascular disruptive syndrome of monozygotic twins

The prenatal histories, clinical courses, and neuroradiographic studies of 8 infants who had survived the in utero demise of a homozygous co-twin were reviewed. Three distinct modes of clinical presentation were found: (1) severe neonatal encephalopathy with seizures; (2) a more benign neonatal course with onset of seizures and profound developmental disabilities within the first 6 months of age; (3) late infantile presentation with seizures. Only the third group had milder outcomes. Neuroradiographic studies demonstrated two pathologic patterns: varying degrees of periventricular white matter infarction with migrational abnormalities observed with earlier demise of the co-twin, and multicystic encephalomalacia observed when the demise occurred at or near term. Pathophysiology is uncertain and most likely multifactorial. Exsanguination injury to the survivor can occur acutely following co-twin demise, so urgent delivery may be appropriate at or near term.     

White cell subsets in apheresis and filtered platelet concentrates

BACKGROUND: White cell (WBC)-reduced platelet concentrates (PCs) are defined by their absolute WBC count, a criterion which provides no information regarding the various WBC subsets contained in the PC. These heterogeneous cells are known to mediate different physiologic and pathophysiologic functions and account for distinct adverse transfusion responses. This study describes a method which allows the detection and quantification of these subsets and characterizes their presence in a variety of platelet components. STUDY DESIGN AND METHODS: Random-donor pooled PCs (RD PCs) and single-donor apheresis PCs (SD PCs) were studied. RD PCs consisting of 6 units of 2- to 3-day old PCs were randomly assigned to be filtered with one of four WBC-reduction filters from three different manufacturers (n=34). The residual WBCs were pelleted by centrifugation and isolated on a density gradient. The various WBC subsets were quantified by flow cytometry in unfiltered and filtered PCs using fluorescence and two-angle light scatter. SD PCs obtained with two manufacturer's systems and three processing protocols (n=30) were studied in like manner. RESULTS: WBC counts for non-WBC- reduced PCs averaged 3 × 10(8) in RD PCs and ranged from 8.6 to 9.6 × 10(6) per SD PC. Residual WBC counts in filtered PCs ranged from 2.3 × 10(4) to 2.2 × 10(5) and those in WBC-reduced SD PCs averaged 2.2 × 10(5) per unit. The data demonstrate significant phenotypic differences among PCs produced with various procedures. All SD PCs and two of four filtered RD PCs contained five WBC populations including granulocytes and monocytes, while RD PCs filtered with the remaining manufacturer's devices contained only lymphocytes. CONCLUSION: The data confirm that distinct phenotypic differences exist among PCs prepared with different devices and/or procedures. It is suggested that as for non-generic pharmaceuticals, the clinical benefits of these various PCs should be individually proved.     

The effect of malonyldialdehyde on erythrocyte deformability

The addition of malonyldialdehyde (5-20 micro M) to human erythrocytes results in a marked decrease in cellular deformability as measured with a counter-rotating, cone plate Rheoscope when low shear forces (2.5-25 dynes/sq cm) are applied. At high shear forces (125-500 dynes/sq cm), malonyldialdehyde at 5 micro M had no effect on deformability, although at concentrations of 10 and 20 micro M a small but statistically significant decrease was evident. These effects of this crosslinking agent are observed in the absence of alterations in cell volume and intracellular viscosity. The results obtained are in accord with the view that the polymerization of membrane constituents may contribute to the events that lead to the removal from the circulation of either aging cells or cells exposed to peroxidation-initiating agents.     

Digital radiography.Results of a survey (part A) and a consensus conference (part B)

Digital imaging (digital image intensifier radiography, storage phosphor/selenium radiography) is increasingly becoming commonplace in radiology departments for diagnostic purposes. Despite 10 years of experience, the advantages and disadvantages of those methods are still heavily discussed among users, financiers and prescribers. This paper is to offer additional arguments for a thorough and objective discussion. No further comments or interpretations have been added to this paper. This paper consists of two main parts, A and B. The first part deals with the results of a user survey, the other part presents the results, i. e. statements, of a consensus conference.     

烟酰胺类和吡啶丙烯酰胺类衍生物的合成及扩血管活性

烟酰胺类和吡啶丙烯酰胺类衍生物的合成及扩血管活性傅焕建，朱莉亚，林紫云（中国医学科学院，中国协和医科大学药物研究所，北京１０００５０）高血压流行病学的调查表明［１］，我国每年至少有９５万以上高血压病人，所以高血压病是一类常见病，多发病。目前临床应用的...