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排序方式: 共有1510条查询结果,搜索用时 31 毫秒
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Liana Beni-Adani Naresh Biani Liat Ben-Sirah Shlomi Constantini 《Child's nervous system》2006,22(12):1543-1563
Background and objective The classification of hydrocephalus in newborns and in infants is different from the classification in adulthood. This difference
exists due to disparity in the source pathologies that produce the hydrocephalus, and the practical distinctions in prognosis
and treatment choices. The objective of this paper is to present the spectrum of obstructive-communicating hydrocephalus,
which is more complex in the pediatric group, and to propose the relevance of this particular classification to treatment
options.
Materials and methods The authors categorized infants with active hydrocephalus at time of presentation into the following four groups along the
spectrum of communicating vs obstructive HCP. Group 1: patients with a purely absorptive (communicating) HCP. In these patients,
tetraventricular dilatation is usually observed with occasional extraaxial fluid accumulation. An extracranial CSF diversion
(shunt) is the treatment of choice. Group 2: patients with an obstructive component together with a persistent absorptive
component. In these patients, a technically successful endoscopic procedure will not prevent progression of clinical symptoms
of HCP. An extracranial CSF diversion (shunt) should be the treatment of choice even though some of these patients are currently
treated by endoscopy. Group 3: patients with an obstructive component together with a temporary absorptive component. In these
patients, a technically successful ETV should be followed by temporary CSF drainage [via LP, continuous spinal drainage (CLD),
or ventriculostomy] with or without supplemental medical treatment (i.e., Diamox) for several days. Such temporary drainage
may decrease failure rate in this subgroup. Group 4: patients with a purely obstructive HCP. In these patients, an endoscopic
procedure (ETV) is the treatment of choice. According to this spectrum classification, the authors classify different entities
with representative cases and discuss relevancy to treatment options and prognosis.
Results The data suggest that obstructive hydrocephalus in the very young population may be rather a combination of obstructive and
absorptive problem. The outcome of the patient depends mainly not only on the basic pathology causing the hydrocephalus but
also on the treatment that is chosen and its complications. While bleeding and infection represent the major causes for communicating
hydrocephalus, patients with complex pathologies of congenital type and intra- or interventricular obstructions may reflect
obstructive hydrocephalus. Treatment of these patients may be successful by shuntless procedures if the absorptive problem
is not the major component. In transient absorptive hydrocephalus, temporary measures were effective in many cases leading
to successful procedures of ETV and/or posterior-fossa decompression in selected cases.
Conclusions Shuntless procedures are the dream of a pediatric neurosurgeon provided it solves the problem and does not imply unacceptable
risk. However, the benefit has to be evaluated years after the procedure is performed, as only prospective multicenter studies
will truly show which procedure may have the best overall results in the developing child. Until such studies are available,
understanding the basic pathology or the combination of pathologies leading to hydrocephalus in a given child may open the
window of opportunities for other than shunt surgery in many hydrocephalic children with major obstructive component. 相似文献
5.
W Romaniuk 《Klinika oczna》1992,94(10):301-302
The methods of extracapsular cataract extraction generated some problems connected with postoperative opacification of the posterior capsule. The authors present clinical and experimental methods applied nowadays, intended to prevent these opacifications from forming. 相似文献
6.
Utility of Major Leukocyte Subpopulations for Monitoring Secondary Cytomegalovirus Infections in Renal-Allograft Recipients by PCR 总被引:2,自引:1,他引:2
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Peter Schfer Werner Tenschert Liana Cremaschi Kai Gutensohn Rainer Laufs 《Journal of clinical microbiology》1998,36(4):1008-1014
The feasibility of the major peripheral blood leukocyte (PBL) subsets for use in qualitative and quantitative PCR to monitor secondary cytomegalovirus (CMV) infection and ganciclovir therapy was assessed with 188 blood samples derived from 40 CMV immunoglobulin G-positive renal-allograft recipients. In pp65 antigen-positive patients all leukocyte fractions, but only 79.5% of plasma preparations, were PCR positive. In pp65 antigen-negative samples from patients after antiviral treatment only 7.3% of polymorphonuclear cell (PMNL) samples, but 81.8% of peripheral blood mononuclear cells (PBMC), and 10.9% of plasma samples remained PCR positive. Similarly, in patients with latent infections only 5.0% of PMNL, but 51.7% of PBMC preparations, and 8.0% of plasma samples were PCR positive. Regarding patients with active CMV infection, CMV DNA copy numbers in PMNL correlated significantly with pp65 antigen-positive cell counts before and after onset of ganciclovir therapy. Significant differences in CMV DNA copy numbers in PMNL and plasma were observed (i) between patients with symptomatic infection and those with asymptomatic infection and (ii) between patients with active infection and those with latent infection. In contrast, PBMC harbored equally low CMV DNA levels both in patients with active infection and those with latent infections, and no decline of CMV DNA load in PBMC was observed during antiviral treatment. We conclude that detection of CMV DNA in PMNL, not in PBMC, is associated with active infections and is more sensitive than detection of CMV DNA in plasma. Negative PCR results for PMNL after antiviral therapy indicate recovery, and fewer unwanted positive results occur compared to PBMC and plasma. Therefore, purified PMNL should be preferred for analysis by qualitative CMV PCR to avoid unwanted positive results. The CMV DNA load in PBMC compared with that in PMNL is negligible during active infection, so mixed PBL are sufficient for use in quantitative PCR. 相似文献
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The specification of a germ cell as sperm or oocyte and determination of cell number remain unsolved questions in developmental biology. This paper examines Caenorhabditis elegans FOG-1, a CPEB-related RNA-binding protein that controls the sperm fate. We find that abundant FOG-1 protein is observed transiently in germ cells just prior to their expression of an early sperm-differentiation marker. As the germline tissue elongates, abundant FOG-1 appears more and more distally as sperm become specified, but disappears when the germ line switches to oogenesis. This dynamic pattern is controlled by both globally acting and germline-specific sex-determining regulators. Importantly, the extent of FOG-1 expression corresponds roughly to sperm number in wild-type and mutants, altering sperm number. By contrast, three other key regulators of the sperm/oocyte decision do not similarly correspond to sperm number. We suggest that FOG-1 is precisely modulated in both time and space to specify sperm fate and control sperm number. 相似文献
9.
Fidani L Goulas A Crook R Petersen RC Tangalos E Kotsis A Hardy J 《Neuroscience letters》2004,357(2):152-154
Cholesteryl ester transfer protein (CETP) is reportedly able to affect the amount of cholesterol available for deposition and/or removal from peripheral tissues, in its capacity to mediate the transfer of cholesterol from high density lipoprotein (HDL) to very low density lipoprotein, in exchange for triacylglycerols from the latter. The TaqI B polymorphism of the human CETP gene has been associated with decreased CETP mass and an increase in HDL-cholesterol. While many studies have addressed the atherogenic or anti-atherogenic potential of this polymorphism, little is known about its effect on neurodegeneration, despite the fact that CETP is expressed in the brain and the disturbance of cholesterol homeostasis appears to be an important factor in the pathogenesis of Alzheimer's disease (AD). In this report, we have compared the distribution of the TaqI B polymorphism in an independent population of 102 clinically diagnosed late onset AD patients and a spousal control group of 97 individuals. We have also examined the possible interaction between this polymorphism and two other polymorphisms suspected of affecting cholesterol flux, namely apolipoprotein E APOE epsilon4, and lipoprotein lipase LPLS447X. No statistically significant differences have emerged with respect to either genotype or allele frequencies between the AD and control populations. CETP TaqI B did not interact significantly with either APOE epsilon4 or LPLS447X, in this study. 相似文献
10.
Previous studies have suggested that the optimum length for force generation of the parasternal intercostal (PS) muscles is well above functional residual capacity (FRC). We further explored this issue by examining the pressure-generating capacity of the PS muscles as a function of lung volume in anaesthetized dogs. Upper thoracic spinal cord stimulation (SCS) was used to electrically activate the PS muscles. Changes in airway pressure and parasternal resting length (LR) during airway occlusion were monitored over a wide range of lung volumes during SCS. To assess the effects of parasternal contraction alone, SCS was performed following phrenicotomy and section of the external intercostal, levator costae and triangularis sterni muscles. With increasing lung volume, there were progressive decrements in the capacity of the PS muscles to produce changes in airway pressure. The relationship between PS pressure generation and lung volume was similar to a previous comparable assessment of the external intercostal muscles. The PS muscles shortened during passive inflation and also shortened further (by > 20 % of LR) during SCS. Total shortening (passive plus active) increased progressively with increasing lung volume. Our results indicate that the capacity of the PS muscles to produce changes in airway pressure (a) falls progressively with increasing lung volume and (b) is similar to that of the external intercostal muscles. We speculate that the fall in PS pressure-generating capacity is related, in part, to progressive reductions in end-inspiratory length. 相似文献