Multichannel cochlear implantation in obliterated cochleas using the Gantz procedure

Gantz, et al, reported two patients with extensive cochlear ossification in which cochlear implantation was done with a Nucleus 22-Channel Cochlear Implant after extensive cochlear drill-out. One of the patients did well with 20 functioning electrode pairs. We report an additional three patients with extensive cochlear ossification who received Nucleus 22-Channel Cochlear Implants. All three patients had extensive cochlear drill-out as described by Gantz, et al. All three patients have use of all 21 electrode pairs with amperages typical of conventional implantation in two of the three and slightly increased levels in the third. Extensive bilateral cochlear ossification does not seem to be an absolute contraindication for multi-channel cochlear implantation.     

Ophthalmoplegia and ptosis in congenital fiber type disproportion

Bilateral ophthalmoplegia and ptosis is reported for the first time in a patient with a rare neuromuscular disorder, congenital fiber type disproportion (CFTD). The importance of limb muscle biopsy in the diagnostic evaluation is emphasized. A summary is presented of other congenital neuromuscular diseases which may have associated ophthalmoplegia.     

Effect of different dialysis membranes on platelet function. A tool for biocompatibility evaluation

Intradialytic coagulative and platelet activation, one of the main consequences of blood-membrane contact, was studied in a group of 5 RDT patients with a comparative evaluation of 3 different dialytic membranes: Cuprophan (CU), Polysulfone (PS) and Cellulose Triacetate (CT). Each patient underwent 5 consecutive dialysis sessions with the above mentioned membranes. Intradialytic platelet activation was studied through a morpho-functional evaluation between the mean platelet volume (MPV) and Serotonin (S), beta-Thromboglobulin (beta-TG) and Platelet Factor 4 (PF4) serum levels. These determinations were made before HD (time 0) and after 30', 120', and 240'. We also checked the intradialytic status of thrombogenesis and fibrinolysis determining aPTT, thrombin time, fibrinogen, antithrombin III (AT III), alpha-2 antiplasmin and plasminogen, at the same time intervals. All membranes tested (CU, PS, CT) caused appreciable intradialytic platelet activation, above all after 15' and at the end of dialysis sessions, more marked for CU than PS or CT. In particular MPV showed a decrease throughout the session (-5% at 30' and -9% at 240') while S, beta TG and PF4 peripheral blood levels showed a significant increase at the same intervals with CU membrane. Lastly coagulative and fibrinolytic parameters showed no significant differences among any of the membranes tested.     

原位合成钛基复合材料增强体TiC的微结构特征

利用钛与石墨之间的自蔓燃高温合成反应经普通的钛合金铸造工艺制备了TiC增强的钛基复合材料。借助X射线衍射仪、光学金相显微镜和透射电镜分析了钛基复合材料的物相组成和增强体的微观结构。结果表明：复合材料由TiC增强体和基体钛合金组成。TiC显示 两种不同的形态：树枝晶状和等轴或近似等轴状。原位合成的增强体TiC以溶解-析出的方式生长。从二元相图分析,凝固过程经历三个阶段： 初晶TiC,二元共晶β-Ti+TiC和固态相变。由于成分过冷的形成,初晶TiC以树枝晶的形态生长。二元共晶TiC以等轴或近似等轴状生长。少量的TiC在形核与长大的过程中形成孪晶结构,孪晶面是(111)面。     

The vascularity and remodelling of subchondrial bone and calcified cartilage in adult human femoral and humeral heads. An age- and stress-related phenomenon

A quantitative study of the vascularity and a qualitative study of the remodelling of the calcified cartilage and subchondral bone end-plate of adult human femoral and humeral heads were performed with respect to age. In the femoral head the number of vessels per unit area was found to fall 20% from adolescence until the seventh decade and in the humeral head 15% until the sixth decade. Thereafter an increase was noted in the femur but none in the humerus. More vessels were present at all ages in the more loaded areas of the articular surfaces: 25% more for the femur and 15% more for the humerus. The degree of active remodelling by endochondral ossification declined 50% from adolescence until the seventh decade in the femoral head, and 30% until the sixth decade in the humeral head, rising thereafter to levels comparable to those found at young ages. More remodeling was noted in the more loaded areas at all ages.     

The chromosomal distribution of mouse odorant receptor genes

Odorant receptors (ORs) on nasal olfactory sensory neurons are encoded by a large multigene family. Each member of the family is expressed in a small percentage of neurons that are confined to one of several spatial zones in the nose but are randomly distributed throughout that zone. This pattern of expression suggests that when the sensory neuron selects which OR gene to express it may be confined to a particular zonal gene set of several hundred OR genes but select from among the members of that set via a stochastic mechanism. Both locus-dependent and locus-independent models of OR gene choice have been proposed. To investigate the feasibility of these models, we determined the chromosomal locations of 21 OR genes expressed in four different spatial zones. We found that OR genes are clustered within multiple loci that are broadly distributed in the genome. These loci lie within paralogous chromosomal regions that appear to have arisen by duplications of large chromosomal domains followed by extensive gene duplication and divergence. Our studies show that OR genes expressed in the same zone map to numerous loci; moreover, a single locus can contain genes expressed in different zones. These findings raise the possibility that OR gene choice may be locus-independent or involve consecutive stochastic choices.     

Cerebrovascular complications of HIV in children

Two uncommon but important cerebrovascular manifestations of human immunodeficiency virus (HIV) infection in children are arteritis with formation of fusiform aneurysms and arterial sclerosis with vascular occlusion. We studied the CT and MR imaging features of HIV in two girls and one boy (9 to 18 years old) and compared them with autopsy findings in two patients. One of the children had findings consistent with small areas of subacute infarction and the other two had fusiform dilatation of the major vessels of the circle of Willis. The ischemic lesions and arteriopathy were confirmed at autopsy. In one patient, an incidental B-cell lymphoma (not visible on the imaging studies) was diagnosed.