Wilms' tumor with intracaval thrombus in the UK Children's Cancer Study Group UKW3 trial

Background/Purpose

To define the clinical characteristics and surgical management of intracaval involvement in patients enrolled in the UKW3 trial (1991-2001), which recommended elective preoperative chemotherapy for such cases.

Methods

Cases were identified from preoperative imaging and surgical trial forms. These asked specific questions about whether the surgeon suspected intracaval extension at diagnosis or found it at nephrectomy. For tumors with Wilms' histology, original case notes were examined.

Results

Of 842 patients registered in UKW3, 730 (87%) had Wilms' tumor. Among them, 59 (8.1%) had evidence of intracaval extension, either documented at diagnosis (53) or found unexpectedly at nephrectomy (6). Intracaval extension was also seen in tumors of other histology. The level of thrombus was intraatrial (10), suprahepatic (9), retrohepatic (8), infrahepatic (26), and unknown (6). The median age at diagnosis was 3.75 years compared to 2.97 years in patients without inferior vena cava thrombus (P < .0001). Fifty-two of 59 received preoperative chemotherapy. Thirty-one (52%) needed cavotomy, and 3 (30%) with intraatrial extension required cardiopulmonary bypass. The commonest operative complication was significant hemorrhage and resulted in mortality in 3 cases.

Conclusions

Preoperative chemotherapy is a useful adjunct to shrink the tumor and thrombus. This reduces the requirement for cavotomy and cardiopulmonary bypass. Intraoperative hemorrhage remains a significant cause of operative morbidity and mortality.     

下斜肌转位术对伴有下斜肌亢进DVD的矫正作用

目的 探讨下斜肌转位术对伴有下斜肌亢进的垂直分离性斜视(dissociated verticaldeviation,DVD)原在位垂直斜视的矫正作用.方法应用下斜肌转位术治疗34例(46只眼)伴有下斜肌亢进DVD患者的垂直斜视,18例合并水平斜视者同期手术矫正,手术前后测量原在位垂直斜视度及下斜肌亢进程度,并进行统计学比较.结果原在位垂直斜视度5m远距离平均矫正(13.57±9.74)PD(t=9.450,P<0.01),95%置信区间为(10.67,16.46)PD.33cm近距离平均矫正(13.28±9.98)PD(t=9.029,P<0.01),95%置信区间为(10.32,16.25)PD.下斜肌亢进程度从术前平均+2降至术后0(Wilcoxon符号秩检验,Z=5.957,P<0.01),差异均具有统计学意义.结论下斜肌转位术是治疗伴有下斜肌亢进DVD的有效手段.合并之下斜肌亢进同时得以消除.     

Neonatal sensorineural hearing loss affects neurone size in cat auditory midbrain

We examined the effect of a neonatal sensorineural hearing loss on the soma area of neurones in the central nucleus of the inferior colliculus (ICC) in adult cats to evaluate the role of auditory experience on neuronal atrophy within the auditory midbrain. Three groups of animals were used: bilaterally deafened, unilaterally deafened and normal hearing controls. Soma area measurements were made from the laminated central and medial divisions of the ICC of eight deafened and two normal hearing cats. A small but significant reduction in soma area was evident for bilaterally deafened animals compared with normal hearing controls (P<0.05, Dunnett’s test). In contrast, there was no significant difference in mean soma area between normal hearing and unilaterally deafened animals (P>0.05) irrespective of whether the ICC examined was ipsi- or contralateral to the deafened ear. These results demonstrate that the reduction in soma area of auditory brainstem neurones reported following a sensorineural hearing loss is also evident at the level of the auditory midbrain.     

布加综合征下腔静脉梗阻的超声分型探讨

目的 探讨布加综合征下腔静脉梗阻的超声分型。方法 对128例布加综合征患者的超声声像图进行分析、分型，除瘤栓阻塞型外全部病例均经X线下腔静脉造影证实。结果根据病因及声像图表现将布加综合征下腔静脉梗阻分为四种类型：膜型狭窄型、膜型闭塞型、节段性狭窄型、瘤栓阻塞型。结论 超声检查可显示布加综合征下腔静脉梗阻的部位、类型、范围和梗阻程度，对布加综合征的诊断、分型及治疗方案的选择具有重要意义，是筛选和诊断布加综合征的首选方法。     

Tonotopic bands produced by tones commenced long after 2-deoxyglucose injection

Presentation of two different tones at two different time periods each under two different types (¹⁴C or ³H) of 2-deoxyglucose (2-DG) produced two bands of labelling in the inferior colliculus (IC) of a guinea pig. Filtering tests revealed that both bands were produced by only one of the labels (¹⁴C). Four guinea pigs were given one injection of 2-DG and then stimulated with two tones, each presented at different time periods. Two bands of labelling were produced in IC, with one band being produced by tones given 55–90 min after injection. The implications of this long lasting effect of 2-DG are discussed for the general 2-DG model and for sequential double labelling experiments.     

Postnatal development of the corticotectal projection in cats.

Although numerous physiological studies have provided compelling evidence for the involvement of the corticotectal projection in the normal development of visual response properties of neurons in the superior colliculus, little information is available on the morphological development of corticotectal axons. Thus, our goal was to determine the postnatal changes characterizing the development of the topography and morphology of corticotectal axon arbors. Topographically restricted injections of Phaseolus vulgaris leucoagglutinin were made into striate cortex to label corticotectal axons and their terminal arbors. Following injections of similar size and location in kittens and adult cats, a similar, localized region of the superior colliculus was labeled at all ages. However, while present in the appropriate topographic location in colliculus, the corticotectal projection revealed a greater tangential distribution in kittens than adults. Corticotectal terminal zones underwent a twofold decrease in tangential area during the first 8 weeks after birth. From corticotectal terminal zones in kittens, extended many fine collaterals that ended as growth cones and radiated up to 1 mm from the focus of the terminal zone. By 8 weeks after birth, these immature collaterals were no longer observed, and the corticotectal terminal zone was indistinguishable from those in 12-week-old kittens and adult cats. Corticotectal axon arbors became more specialized in the first 8 weeks after birth; both en passant and terminal swellings increased in diameter, and terminal swellings increased in number, although the total number of swellings per unit length of axon remained relatively stable. The number of axonal branches increased threefold between 1 and 8 weeks after birth. Thus, as the corticotectal projection becomes spatially restricted during development, individual arbors become progressively more intricate with regard to focused collateral branching and the elaboration of complex axonal specializations.     

The distribution of hexokinase compared to cytochrome oxidase and acetylcholinesterase in the somatosensory cortex and the superior colliculus of the rat

The distribution of hexokinase, a general glycolytic enzyme, was compared to that of cytochrome oxidase and acetylcholinesterase (AChE) in the somatosensory cortex and the superior colliculus of the rat. The vibrissal barrel fields of the adult rat contain high hexokinase and cytochrome oxidase activity and low AChE activity. In the superior colliculus, hexokinase activity was highest in cell layers and discrete foci of intense activity were observed in the deep grey layer. This distribution was different from that of both cytochrome oxidase and AChE in this structure.     

Decortication abolishes place but not cue learning in rats

The experiments examined whether decorticate rats are able to acquire a place learning strategy, as compared with a cue learning strategy, to successfully navigate from one place to another and whether the hippocampus, in the absence of the neocortex, contributes to successful performance. Decorticate rats, with or without hippocampectomy, were unable to locate an “invisible” platform submerged at a fixed place in a tank of cool water (made opaque by milk), rather they scrabbled at the edges of the tank and failed even to initiate search strategies. They were able to learn to swim directly to the platform if it was visible. Their ability to find the hidden platform was not enhanced by presurgical experience or two-stage ablations with training before and after ablations. When pretrained on the cue task and tested on the place task, they learned to inhibit scrabbling at the tank edges and “search” in a haphazard fashion for the hidden platform, but they never learned to swim directly toward it. When decorticate rats, trained on the cue task, received superior colliculus or basal ganglia removal in a second operation, cue learning was abolished. Hippocampal removal after decortication left performance on the cue task unaffected. The results demonstrate: (1) the integrity of the neocortex is essential for place learning; (2) the brainstem, including superior colliculus and basal ganglia, is sufficient for cue learning; and (3) in the absence of the neocortex the hippocampus plays no role in guiding either type of navigation. It is concluded that sensorimotor subsystems of the forebrain play a special role as detector-response systems for guiding behaviour in response to constellations of distal stimuli, whereas subcortical structures are sufficient for navigation to a single stimulus.     

Auditory space representation in the superior colliculus of the big brown bat, Eptesicus fuscus

The auditory response areas of 123 superior collicular (SC) units of Eptesicus fuscus were studied under free-field acoustic stimulus conditions. A stimulus was delivered from a loudspeaker placed 14 cm in front of a bat. The best frequency of a unit was determined by changing the stimulus frequency until the minimum threshold was measured. A best frequency stimulus was then delivered as the loudspeaker was moved across the auditory space to determine the response center of the auditory response area of each unit. The response center was defined as the direction at which the unit had its lowest minimum threshold. The stimulus intensity was then raised 2–20 dB above the lowest minimum threshold of the unit and the response area for each stimulus intensity was determined.The response area of a unit expands with stimulus intensity, but the expansion is not even in all directions. The size of the response area of a unit does not correlate with its minimum threshold, best frequency, or recording depth. Response centers of 7 units were located directly in front of the animal, but most response centers were located in a limited portion of the contralateral auditory space.Although each unit has a response center which is the point of maximal sensitivity, the point-to-point representation of the auditory space is not systematically organized. We suggest that an animal with highly mobile external pinnae may not need an orderly auditory space map in its neural tissue for accurate sound localization.     

Optic fiber development between dual transplants of retina and superior colliculus placed in the occipital cortex

Summary Fetal rat retina was excised from donor rats at 15 days of gestation and transplanted to the occipital cortex of neonatal host rats in combination with and adjacent to: 1) the appropriate portion of the superior colliculus to serve as a specific target tissue in an attempt to stimulate an outgrowth of optic fibers from the isolated retinal transplant; 2) a sample of the medial thalamus to provide a alternate tissue not normally recipient to the retinofugal projection, thereby serving as a control to further test for the target specificity of the axonal outgrowth from the retinal transplant. After 5–30 days of development samples of transplant and surrounding host cortex were removed and subjected to light and electron microscopic study.The fetal retina has been shown to develop successfully while located in the occipital cortex but this tissue does not form a significant number of optic fibers nor does it demonstrate the normal quantity of ganglion cells, (Matthews et al. 1981). A dual transplant of fetal retina and medial thalamus demonstrates the major types of neurons and sensory elements in the retina as well as concentrations of large neurons in the thalamus. Examination of these transplants with a silver stain, as well as electron microscopy, revealed a network of axons coursing within the transplanted thalamic neuropil but few axons traversing the interface between the retinal and thalamic transplant. Additionally, no axons coursed out of the retina into the surrounding host cortex.Similar studies of dual transplants of retina and superior colliculus revealed marked concentrations of fibers projecting from the periphery of the retinal tissue, extending deep into the adjacent superior colliculus and merging with the tangle of axons found within this tissue. It should be emphasized, however, that such outgrowths from the retina were clearly restricted to those portions in apposition to the transplanted tectum. No axons were found extending from the opposite surface of the retinal transplant in contact with the host cortex.A quantitative analysis of ganglion cell populations in the transplant demonstrated that these were somewhat reduced in all retinal transplants with the exception of those regions located adjacent to a transplant of superimental enlargement of a peripheral target organ during early stages of development reduces the amount of spontaneous neuronal degeneration resulting from a failure to establish functional connections with the available postsynaptic sites in the target.Our experiments indicate that the use of multiple transplants may provide a useful model system for further exploration of the relationship between developing CNS neurons and tissues within the CNS or the periphery which receive their input.