Timing of ICAM-I Expression in a Canine Model of Post-Haemorrhagic Cerebral Vasospasm

SUMMARY

Temporal alterations in endothelial intercellular adhesion molecule I (ICAM-I) expression during the course of post-haemorrhagic cerebral vasospasm (PHCV) are correlated with angiographic and histologic changes in the canine basilar artery. Angiography was performed in six dogs to obtain baseline measurements of basilar artery diameter. In three dogs subarachnoid haemorrhage (SAH) was created by performing percutaneous puncture of the cisterna magna, and replacing 7 ml of cerebrospinal fluid with 7 ml of arterial blood. The remaining three dogs were used as controls. Daily angiography was performed on all dogs to determine the percent reduction in basilar artery diameter (%RBAD). One dog from each group was sacrificed after 24 hours. The remaining two dogs in each group were sacrificed after 48 hours. Each basilar artery was perfusion fixed and subjected to histologic, and immunohistochemical analysis. In the SAH group, the average %RBAD was 4 (+/- 3) at 24 hours, and 36 (+/- 1) at 48 hours. In the control group, the average %RBAD was - 1 (+/- 1) at 24 hours, and 0 (+/- 2) at 48 hours. Endothelial edema and endothelial expression of ICAM-I were found at 24 hours.At 48 hours post-SAH there was widespread endothelial desquamation, but no evidence of ICAM-I expression. In the control group, histology was normal and no ICAM-I expression was found at 24 or 48 hours. The results suggest that a brief window of therapeutic efficacy exists during the first postictal 24 hours where ICAM-I antagonists may be useful in suppressing the pathogenesis of PHCV.

[The influence of interferon alpha neutralizing antibodies on the therapeutic effectiveness in patients with chronic viral hepatitis]

OBJECTIVE

To study the influence of interferon alpha (IFN-alpha) neutralizing antibody (NA) on the therapeutic effectiveness of IFN-alpha.

METHODS

30 healthy persons and 116 patients with chronic viral hepatitis treated with IFN-alpha were studied, and the NA in their sera were tested by using the antiviral neutralizing bioassay (ANB).

RESULTS

None was positive for NA in sera of the healthy persons and patients before IFN-alpha treatment, 20 of 116 patients developed NA after IFN-alpha therapy, the positivity was 17.2% (20/116). NA appeared after 2 months of alpha IFN treatment, all 20 patients were positive after 6 months. The NA positivity in treated groups of IFN-alpha 2a, IFN-alpha 2b and IFN-alpha 1b were 34.6%, 13.2% and 11.5% respectively. The clearance rates of virus in NA-positive group and NA high-titered group were significantly lower than those in NA-negative group and NA low-titered group (P < 0.01 and P < 0.05, respectively) In contrast, the relapse rates of virus in NA-positive group was markedly higher than that in NA-negative group (P < 0.05).

CONCLUSION

NA may develop with its regularity in the chronic viral hepatitis patients treated with alpha IFN. The frequencies of NA development are related with the subtypes of alpha IFN used. NA can inhibit IFN activity, thereby affecting the therapeutic effectiveness of IFN.

Robust representations for faces: evidence from visual search

We report evidence from visual search that people can develop robust representations for highly overlearned faces. When observers searched for their own face versus the face of an unfamiliar observer, search slopes and intercepts revealed consistently faster processing of self than stranger. These processing advantages persisted even after hundreds of presentations of the unfamiliar face and even for atypical profile and upside-down views. Observers not only showed rapid asymptotic recognition of their own face as the target, but could reject their own face more quickly as the distractor. These findings suggest that robust representations for a highly overlearned face may (a) mediate rapid asymptotic visual processing, (b) require extensive experience to develop, (c) contain abstract or view-invariant information, (d) facilitate a variety of processes such as target recognition and distractor rejection, and (e) demand less attentional resources.

Binocular rivalry and visual awareness in human extrastriate cortex

We used functional magnetic resonance imaging (fMRI) to monitor stimulus-selective responses of the human fusiform face area (FFA) and parahippocampal place area (PPA) during binocular rivalry in which a face and a house stimulus were presented to different eyes. Though retinal stimulation remained constant, subjects perceived changes from house to face that were accompanied by increasing FFA and decreasing PPA activity; perceived changes from face to house led to the opposite pattern of responses. These responses during rivalry were equal in magnitude to those evoked by nonrivalrous stimulus alternation, suggesting that activity in the FFA and PPA reflects the perceived rather than the retinal stimulus, and that neural competition during binocular rivalry has been resolved by these stages of visual processing.

The effect of face inversion on the human fusiform face area

Inversion severely impairs the recognition of greyscale faces and the ability to see the stimulus as a face in two-tone Mooney images. We used functional magnetic resonance imaging to study the effect of face inversion on the human fusiform face area (FFA). MR signal intensity from the FFA was reduced when greyscale faces were presented upside-down, but this effect was small and inconsistent across subjects when subjects were required to attend to both upright and inverted faces. However when two-tone faces were inverted, the MR signal from the FFA was substantially reduced for all subjects. We conclude that (i) the FFA responds to faces per se, rather than to the low-level visual features present in faces, and (ii) inverted greyscale faces can strongly activate this face-specific mechanism.

Diagnosis and treatment of pulmonary hamartoma

From 1970 to 1997, 67 patients with pulmonary hamartoma were operated on in our hospital. There were 38 men and 29 women with a M/F ratio of 1.3:1. The mean age was 47 years (range 21 to 82 years). The peak incidence was 40 to 60 years. 39% patients had pulmonary symptoms: hemoptysis, cough, phlegm and chest pain. All were solitary. 68.7% tumors were located in right lung and 64.2% in upper or middle lobe. 80.6% hamartomas were less than 3 cm in transverse diameter. On chest films, the opacity was homogeneous in 79.1% cases, heterogeneous in 20.9% and calcifications in 9.0%. The vast majority of shadows were heterogeneous on CT films. Operation is the best treatment for hamartomas. Postoperative mortality was 1.5%. There was none recurrences and canceration during the follow-up (mean 14 years).

Respiratory rate and signs in roentgenographically confirmed pneumonia among children in China

A clinical study was conducted in three Chinese community hospitals to investigate the reliability of respiratory rate and various clinical signs in the diagnosis of pneumonia among 54 children less than 5 years of age. Anteroposterior chest film was used as the diagnostic standard. The cutoff criterion for rapid breathing was 50 breaths/minute for infants ages 2 to 11 months and 40/minute in children 1 to 5 years old. Rapid breathing was a better predictor of pneumonia than rales (positive predictive values of 74.5 and 66.9%). Nasal flaring, chest indrawing, stridor and cyanosis of the tongue had predictive values of > 86%, but these clinical signs were observed in only a small proportion of patients. We recommend that village health workers use rapid breathing for diagnosis of pneumonia, rather than auscultation which is difficult and has proved unreliable. Sensitivity, specificity and positive and negative predictive values are presented for seven signs and symptoms of pneumonia.