Distribution of beta-amyloid precursor and B-cell lymphoma protooncogene proteins in the rat retina after optic nerve transection or vascular lesion

The expression of beta-amyloid precursor protein (APP) and B-cell lymphoma protooncogene protein (Bcl-2) in retinal cells in the rat was studied using immunocytochemistry at different times after intraorbital optic nerve transection or vascular lesion. Three hours to one month after transection of the optic nerve, a significant increase in APP and Bcl-2 immunostaining was observed in retinal Müller glia but not in retinal neurons. In contrast, injury to blood vessels that supply the eye without cutting the optic nerve resulted in a complete loss of APP and Bcl-2 immunostaining in Müller cells and an increase in immunoreactivity in distinct populations of retinal neurons. The overall pattern of APP immunostaining in Müller cells and neurons was essentially the same as that of Bcl-2 under identical experimental conditions. These results suggest that the expression of APP and Bcl-2 in retinal cells is dependent on the nature and severity of injury, and that rapid and common mechanisms are involved in regulating the expression of these molecules.     

Critical carotid artery stenosis: diagnosis, timing of surgery, and outcome

PURPOSE: Patients with critical carotid artery stenoses have been considered to be at high risk for carotid artery occlusion necessitating urgent or emergency endarterectomy once the stenosis is identified. Included in this group of patients are those with carotid string sign or atheromatous pseudoocclusion (APO). This review was conducted to determine the impact of the severity of stenosis including APO on the treatment and outcome of patients undergoing carotid endarterectomy. METHODS: The records of 203 consecutive carotid endarterectomies performed in 197 patients were reviewed in detail. Patients were stratified into a critical stenosis group (80% to 99% diameter) and noncritical stenosis group based on noninvasive vascular laboratory and carotid arteriography results. Comparisons were performed of demographic data, atherosclerotic risk factors, carotid artery disease presentation, interval between arteriography and endarterectomy, operative details, and surgical results between the critical and noncritical groups and between patients in the critical group with and without APO. RESULTS: Carotid endarterectomies were performed on 91 critical carotid artery stenoses and 112 noncritical stenoses. The groups did not differ significantly with regards to demographics, risk factors, carotid artery disease presentation, mean back pressure, and operative use of shunt or patch closure. For the critical group the interval between arteriography and endarterectomy was 8.63 +/- 2.38 days compared with 9.64 +/- 2.14 days for the noncritical group (mean +/- SEM, p = 0.75). No patient in either group progressed to occlusion in the interval between arteriography and endarterectomy. Perioperative strokes occurred in two patients (2%) in the critical group and four patients (3.6%) in the noncritical group (p = 0.09). Likewise, no significant difference was demonstrated in these variables when comparing patients with critical carotid artery stenosis and APO with those without APO. CONCLUSIONS: The presence of a critical carotid artery stenosis including APO did not impact on the treatment or outcome of patients requiring endarterectomy nor did it imply the need for emergency intervention to prevent thrombosis. Surgical intervention can proceed after evaluation and optimization of comorbid conditions without undue concern for interval thrombosis.     

Extensive salivary contamination due to concurrent use of chewing tobacco during I-131 radioablative therapy

Although multiple authors have reported on various causes of external I-131 contamination after administration of radioiodine, to the authors' knowledge there have been no reported cases of external contamination from salivary secretions due to expectoration of chewing tobacco. A case of extensive I-131 contamination of a hospital room, furniture, and plumbing due to indiscriminate use of chewing tobacco during an inpatient I-131 radioablative therapy is presented.     

Prognostic importance of left ventricular diastolic filling velocity profiles in dilated cardiomyopathy

To determine the prognostic importance of pulsed Doppler-derived left ventricular diastolic filling velocity profiles and the relationship between Doppler variables and clinical functional status, the follow-up outcome of 58 patients with dilated cardiomyopathy and symptoms of left ventricular dysfunction was analysed. During a mean follow-up period of 31.2 +/- 12.8 months, 23 died of either progressive pump failure or sudden death. Peak early filling velocity (E) was higher and late atrial filling velocity (A) lower in nonsurvivors than in survivors. The E/A ratio was higher and the deceleration time (DT) of early diastole shorter in nonsurvivors. The mortality was significantly higher in patients with an E/A ratio > 2 or a DT < 150 ms than in those without. Repeated Doppler echocardiographic examinations in 31 of 35 survivors after intense treatment showed decreased E, increased A, reduced E/A ratio and prolonged DT in 18 patients with clinical functional improvement, whereas these measurements were unaltered in the remaining 13 patients whose functional status was unchanged or deteriorated. This study suggests that pulsed Doppler-derived left ventricular diastolic filling variables may be important predictors of outcome in dilated cardiomyopathy and provide useful measures in observing the effects of therapy during long-term follow-up of the patients.     

Analysis of a conformation-independent epitope and a conformational epitope in a protein: a study on cobrotoxin from Taiwan cobra venom

The antibodies against cobrotoxin were separated into two antibody preparations by successive affinity chromatographies on reduced and S-carboxymethylated (RCM)-cobrotoxin-Sepharose, and cobrotoxin-Sepharose columns. The antibodies (abbreviated as Abcf-i) that bound with the RCM-cobrotoxin-Sepharose were verified to specifically recognize the continuous epitopes of cobrotoxin, which were insensitive to conformational changes. Whilst the antibodies (abbreviated as Abcf-d) that did not bind with the RCM-cobrotoxin-Sepharose column recognized the conformational epitopes in cobrotoxin. The two antibody preparations were employed to screen the antigenic peptides derived from the proteolytic hydrolysate of cobrotoxin and RCM-cobrotoxin. Five antigenic peptides (AP-4, AP-5, AP-10, AP-11, and AP-12) were obtained from the acid protease A-digested hydrolysate of cobrotoxin, and two antigenic peptides (V8-2 and V8-4) were found in the hydrolysate of RCM-cobrotoxin after hydrolysis with Saccharomyces aureus V8 protease. The segments at positions 1-21 and 22-38 encompassed the peptide fractions, AP-4, AP-5, V8-2, and V8-4, that reacted with Abcf-i, indicating that the two segments bore the continuous epitopes of cobrotoxin. Alternatively, AP-10, AP-11, and AP-12 reacted with both Abcf-i and Abcf-d. The structures of the three peptides had a common segment at positions 43-62, suggesting that this region comprised the conformation-independent epitopes as well as conformational epitopes in cobrotoxin. These results reflected that the conformation-independent and conformational epitopes in a protein can be separately identified.     

Histological evaluation of therapy using a calcium hydroxide dressing for teeth with incompletely formed apices and periapical lesions

Periapical tissue response was evaluated histologically in teeth of 6-month-old dogs with incomplete root formation and periapical lesions in order to compare the effects of two calcium hydroxide-containing pastes prepared with different vehicles on induced root apex formation and repair of the periapical region. A group of teeth with no root canal dressing was used as control. After induction of the periapical lesion, the root canals were instrumented and filled with one of the two pastes (Calen and Calasept), which were renewed monthly for 90 days. At the end of the follow-up period (3 months), the animals were killed. Block sections from the actual areas were dissected free and prepared for histopathological analysis. Both calcium hydroxide pastes helped induce apical sealing and repair of the region, but the Calen paste yielded better results than Calasept. The induced mineralized tissue was predominantly of the cementoid type after the use of both pastes, but the inflammatory infiltrate was significantly less intense with the use of the Calen paste. In the control group, the absence of a root canal dressing impaired the process of periapical repair and yielded no apical root closure in any of the cases analyzed.     

Alcohol expectancies, problem drinking, and adverse health consequences

This study evaluated a measure of positive and negative expected effects of alcohol and their subjective evaluation in the identification of college freshmen at high risk for problem drinking and associated morbidities. It was hypothesized that greater expectations of positive outcomes and fewer negative evaluations of negative outcomes would be associated with reports of heavier drinking and more alcohol-related health problems. College freshmen (n = 328) completed a standardized measure of expectations and subjective evaluations of positive and negative outcomes associated with drinking, and a questionnaire assessing drinking patterns and common alcohol-related health problems. Fifty-two percent of students were male and the mean age was 17.9 years (SD = 0.5). Students' expectations of positive outcomes and their subjective evaluations of both positive and negative outcomes from drinking were significantly correlated with drinking and alcohol-related health problems indices (p < 0.001). Gender, expectation of positive outcomes, and evaluation of negative outcomes explained 29% of the variance in drinking and 15% of the variance in alcohol-related health problems indices. Heavier-drinking students and those reporting more health problems expected more positive effects on their sociability and sexuality (p < 0.03) and were less concerned about cognitive and behavioral impairment as a result of drinking (p < 0.001). Students with more health problems were less concerned that drinking would lead to risk-taking or aggressive behavior (p < 0.003). Positive and negative outcome expectancies and their subjective evaluations accounted for a significant portion of the variability in drinking and alcohol-related health problems.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of polymerase chain reaction amplification of Mycobacterium leprae-specific repetitive sequence in biopsy specimens from leprosy patients

Biopsy specimens were obtained from 102 leprosy patients before chemotherapy and examined by polymerase chain reaction (PCR) using the primers amplifying the 372-bp DNA of a repetitive sequence of Mycobacterium leprae. The PCR results were then compared with bacterial indices (BI) of slit-skin smears and biopsy specimens. The intensities of DNA bands were in general correlated with the numbers of acid-fast bacilli, and even a sample with only one organism gave a PCR positive result. Ten 5-micron sections from each frozen tissue sample were pooled and processed for DNA preparation. PCR was positive for 11 (73.3%) of 15 biopsy specimens with BI of 0 determined for the paraffin sections from the same biopsy samples. PCR also gave positive results for 84 (96.6%) of 87 BI positive biopsy samples. Although the difference in overall results between the two methods was not statistically significant, PCR seemed to have an advantage over microscopic examination in detecting M. leprae in biopsy specimens negative for acid-fast bacilli. Further evaluation of PCR using more specimens from leprosy patients who are bacteriologically negative is warranted to ensure PCR's advantage over the conventional microscopic examination for the diagnosis of leprosy.