Migration of asbestos fibres from subcutaneous injection sites in mice

Crocidolite asbestos fibres, suspended in physiological saline, were injected subcutaneously into one or both flanks of 95 CBA/Lac female mice; 75 control mice received injections of saline only. Most animals were killed at chosen intervals of between 2 and 42 days after injection but some were left for longer periods of up to 623 days. At autopsy, many lymphoid and non-lymphoid structures were removed and examined for the presence of asbestos by the following techniques: haematoxylin and eosin staining followed by conventional and polarized light microscopy; Perl''s stain; microincineration followed by phase-contrast microscopy; maceration with KOH followed by phase-contrast microscopy; and electron microscopy.     

Perception of motion trajectory of object from the moving cast shadow in infants

A moving cast shadow of the object affects the perception of the object's trajectory in adults [Kersten, D., Mamassian, P., & Knill, D. C. (1997). Moving cast shadow induce apparent motion in depth. Perception, 26, 171-192]. In the present study, we investigated by using a habituation-dishabituation procedure whether infants at 4- to 7-months old discriminate the motion trajectory of a ball from the moving shadow it casts. In Experiment 1, 4- to 5-month-old and 6- to 7-month-old were tested for ability to discriminate between a "depth" display containing a ball and a cast shadow with a diagonal trajectory and an "up" display containing a ball with a diagonal trajectory and a cast shadow with a horizontal trajectory. Six- and 7-month-old, but not 4- and 5-month-old, infants looked significantly longer at the "up" display than at the "depth" display. In Experiment 2, we tested whether 4- to 5-month-old and 6- to 7-month-old infants would perceive "up" motion as categorically different from "depth" depending on the object's 3-D trajectory. We used displays containing a ball and a cast shadow with the same trajectories as those in Experiment 1 except that the cast shadows appeared above the ball. These displays did not produce 3-D impressions in adults. Neither age group of infants exhibited significant differences between "up" and "depth" displays. When the results from the two experiments are considered, 6- and 7-month-old infants discriminated the motion trajectory of the ball from the moving cast shadows. This developmental emergence of depth perception from a moving cast shadow at 6 months of age is consistent with that of other pictorial depth cues.     

Prediction of sensitivity of rectal cancer cells in response to preoperative radiotherapy by DNA microarray analysis of gene expression profiles

Preoperative radiotherapy has been widely used to improve local control of disease and to improve survival in the treatment of rectal cancer. However, the response to radiotherapy differs among individual tumors. Our objective here was to identify a set of discriminating genes that can be used for characterization and prediction of response to radiotherapy in rectal cancer. Fifty-two rectal cancer patients who underwent preoperative radiotherapy were studied. Biopsy specimens were obtained from rectal cancer before preoperative radiotherapy. Response to radiotherapy was determined by histopathologic examination of surgically resected specimens and classified as responders or nonresponders. By determining gene expression profiles using human U95Av2 Gene Chip, we identified 33 novel discriminating genes of which the expression differed significantly between responders and nonresponders. Using this gene set, we were able to establish a new model to predict response to radiotherapy in rectal cancer with an accuracy of 82.4%. The list of discriminating genes included growth factor, apoptosis, cell proliferation, signal transduction, or cell adhesion-related genes. Among 33 discriminating genes, apoptosis inducers (lumican, thrombospondin 2, and galectin-1) showed higher expression in responders whereas apoptosis inhibitors (cyclophilin 40 and glutathione peroxidase) showed higher expression in nonresponders. The present study suggested the possibility that gene expression profiling may be useful in predicting response to radiotherapy to establish an individualized tailored therapy for rectal cancer. Global expression profiles of responders and nonresponders may provide insights into the development of novel therapeutic targets.     

A case of bacterial aneurysm that occurred in the external carotid artery

Occurrence of a mycotic aneurysm extracranially is extremely rare. We report our experience with a case of mycotic aneurysm that occurred in the external carotid artery accompanying infectious endocarditis. The case was a 33-year-old male. He visited our hospital with principal complaints of weakness in the lower left side and visual difficulty. Multiple cerebral infarctions were noted in a head MRI. In addition, vegetation was noted on the mitral valve in an echocardiogram, and the patient was admitted to cardiology for infectious endocarditis. Aneurysms were noted in the external carotid artery and the posterior cerebral artery in a cerebral angiogram performed before valve replacement. After administration of antibiotics for 5 weeks, radical surgery was performed for the external carotid artery aneurysm that had remained unchanged. With a satisfactory postoperative course, the patient was able to walk independently after mitral valve replacement and was discharged. We have scoured the literature with regard to mycotic aneurysm occurring extracranially and have studied this case because of this characteristic. When performing cerebral angiography to search for a mycotic aneurysm, the area outside the cranium as well as inside must be closely examined.     

Postoperative change of the cross-sectional area of back musculature after 5 surgical procedures as assessed by magnetic resonance imaging

Many investigators have reported that persistent low back pain may occur after posterior surgical intervention, and studies have investigated the histologic and histochemical changes in back muscle after posterior lumbar spine surgery. The purpose of the current study is to compare the pre- and postoperative cross-sectional area of the back musculature among 5 surgical groups including anterior lumbar interbody fusion, which has no direct invasion of the back musculature, using magnetic resonance imaging, and to correlate the clinical results with the degree of atrophy. The cross-sectional area of the back musculature was measured before and after surgery in T2-weighted axial magnetic resonance images using a computer-linked digitizer. The degree of atrophy (atrophy ratio) was calculated as a ratio of the postoperative cross-sectional area to the preoperative cross-sectional area. Clinical results were evaluated using the Japanese Orthopaedic Association's scores for the management of low back pain. Atrophy of the back musculature was confirmed in each group. However, no significant difference was seen in the atrophy ratio between the groups. Back musculature atrophy occurred even in anterior lumbar interbody fusion, which does not involve any direct surgery of the back muscle. A positive correlation was noted between the atrophy ratio and operation time only in posterior surgery, especially in nonfusion surgery. In conclusion, the current study suggests that a shorter operation time may minimize back muscle injury, and shows that factors inducing back musculature atrophy include not only direct invasion of the back muscle via a posterior approach, but also postoperative external fixation.     

Transient cerebellar mutism caused by bilateral damage to the dentate nuclei after the second posterior fossa surgery. Case report

The authors report on the case of a 6-year-old boy who underwent resection of a midline cerebellar tumor. The boy was able to speak fluently after the operation. Magnetic resonance (MR) imaging showed that the right dentate nucleus had been partially removed along with the tumor, but that the left dentate nucleus remained with the residual tumor. A second operation was performed to remove the residue, after which the child suffered mutism. Three weeks post-surgery, he could only communicate through gestures. He started speaking I week later and regained normal speech 2 months after the operation. Final MR imaging revealed gross-total removal of the tumor and dentate nucleus on the injured left side. The cerebellar mutism was considered to have been caused by bilateral damage to the dentate nuclei and not by unilateral damage.