MR imaging of the normal and abnormal clivus

We retrospectively reviewed 330 T1-weighted sagittal images, 80 T2-weighted sagittal images, and 83 gadopentetate-dimeglumine-enhanced scans of normal adults to determine the MR appearance of the normal adult clivus. MR images of 21 patients with an abnormal clivus (19 with tumor invasion and two with marrow reconversion) were also evaluated restrospectively and compared with those of the control group to assess MR features distinguishing the two groups. Our study revealed that a normal adult clivus consisted of low- and high-intensity portions mixed in various proportions on T1-weighted images. The low-intensity portion was isointense or hyperintense relative to the pons and always contained foci of bright signal intensity. The low-intensity tumor of a pathologic clivus tended to be hypointense relative to the pons (17/19), and was completely devoid of foci of bright signal intensity. The normal adult clivus was approximately isointense relative to the pons on T2-weighted images. Clival tumors were grossly hyperintense relative to the pons on T2-weighted images in 11 of 17 patients. In the remaining six patients, either a portion of or the entire lesion was isointense relative to the pons and, therefore, was not detectable on T2-weighted images. A normal adult clivus can enhance to some degree (19/83). Clival tumors were found to enhance intensely. A clivus of very low signal intensity (signal void) on T1- or T2-weighted images was always abnormal. The clivus with marrow reconversion was uniformly hypointense relative to the pons on T1-weighted images and isointense relative to normal marrow on T2-weighted images.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of intention to learn novel, environmental sounds on the novelty P3 and old/new recognition memory.

Brain electrical activity was recorded while 32 young adults listened to frequent tones, infrequent target tones, and infrequent novel environmental sounds (some of which repeated). Subjects in the incidental group were not informed about the novel sounds, while subjects in the intentional group were informed and, in addition, were asked to memorize them for a subsequent memory test. Following the novelty oddball task, all subjects were given an old/new sound recognition memory task. The novelty P3 showed a more anterior scalp distribution and an effect of repetition in the incidental compared to the intentional group, suggesting that pre-categorizing the novel sounds influenced how they were processed. For the intentional group only, a subsequent memory effect was elicited by novel sounds that were subsequently recognized compared to those that were not, although both groups showed robust old/new ERP effects during the recognition task. The robust subsequent memory effects in the intentional group were associated with greater recognition accuracy of familiar environmental sounds relative to the incidental group. These data suggest that the encoding activity reflected in the ERP subsequent memory effect may have engendered an advantage in subsequent recognition memory performance.     

Book Review: SCI & Sexuality. The Research and Training Center on Independent Living,University of Kansas/Life Span Institute,Lawrence KS. 1999. 32 pp.

Sexuality and Disability -     

Clinical characteristics of malignant melanomas developing in persons with dysplastic nevi

A total of 452 patients with dysplastic nevi (DN) were followed prospectively by repetitive, complete cutaneous examinations in order to determine the clinical features of early malignant melanomas (MM) arising in them. Sixteen patients (3.5%) developed 18 newly diagnosed MM during an average follow-up period of 27 months. Twelve of the 18 MM were in situ and all of the primary invasive MM diagnosed prospectively in this follow-up were less than 0.89 mm in Breslow thickness, implying an excellent prognosis. The principal clinical clue to the diagnosis of MM was change in a preexisting pigmented lesion. Total-body photographs were very useful in helping to identify the early MM in these patients.     

Beta-carotene serum response in young and elderly females

This study was designed to investigate the effects of aging and food intake on the serum beta-carotene (BC) response curve in humans. Ten elderly (71 +/- 4 years) and 17 young (28 +/- 7 years) healthy females were given 15 mg BC with a semi-solid test meal devoid of BC and vitamin A. All the elderly and 10 young subjects (control A) received a test meal of 500 kcal while the remaining 7 young subjects (control B) were given 700 kcal. Subsequently, blood was drawn hourly for 8 h and again at 24 and 48 h. Serum carotenoids and retinoids were measured by HPLC and triglycerides (TG) and cholesterol by enzymatic methods. Small intestinal transit time was determined in the elderly and in control group A by a breath hydrogen test following ingestion of lactulose (12 g) with the test meal. The area under the absorption curve (AUC) of serum BC over the first 8 h was higher in the elderly subjects than in either control group A or B (P less than 0.001). The slopes of the BC and TG curves were significantly higher as compared to control A, but similar to control B. There was a positive correlation between the ascending slopes of the BC and TG absorption curves of all groups (P less than 0.001). The AUC of the retinyl ester serum response of the elderly group was greater than that of control A (P less than 0.001). The slope of this curve was steeper (P less than 0.01) in the elderly group as compared to control A, but was similar to control B. Intestinal transit time was similar in all groups. In young subjects, the larger test meal of control group B appeared to increase the rate of absorption of BC. These data indicate that the rate of intact BC absorption and its conversion to retinyl esters may be enhanced in old age as compared to younger subjects receiving the same amount of food. Age-related alterations of enterocytes and the intestinal lumen could account for this phenomenon.     

The association of biliary and pancreatic anomalies with periampullary duodenal diverticula. Correlation with clinical presentations

Fifty-eight symptomatic patients with periampullary duodenal diverticula (PDD) were examined for pancreatic and biliary anomalies using endoscopic retrograde cholangiopancreatography (ERCP), ultrasonography, and other imaging modalities. The pathologic findings in these patients were compared with those in a matched group of 58 patients without PDD, who were simultaneously undergoing a similar investigation for the same clinical presentations. Pathologic findings in the pancreas and/or biliary tree were detected in 70.7% of all patients with PDD, compared with 39.7% in the control group. In patients with PDD, pancreatobiliary anomalies were detected in all patients who presented with jaundice, 85% of patients with pancreatitis, and 27.8% of patients with abdominal pain, as compared with 60%, 40%, and 17%, respectively, in the control group. In 23 patients, ERCP findings demonstrated pancreatobiliary abnormalities that were not detected by other imaging modalities. Fifteen of the patients with PDD and pancreatobiliary anomalies had undergone cholecystectomy between six months and five years previously. We conclude that ERCP is essential in the investigation of all patients with PDD, especially those presenting with jaundice or pancreatitis. Biliary surgery in patients with PDD and a dilated bile duct should include a biliary drainage procedure to prevent recurrence of pancreatobiliary disease.     

Subcutaneous fat necrosis of the newborn: light, ultrastructural and histochemical microscopic studies

Multiple subcutaneous plaques and nodules appeared on the back and the dorsal proximal area of the extremities of a 9-day-old male infant after a complicated prenatal period necessitating cesarean section. The clinical and histological features were diagnostic of subcutaneous fat necrosis of the newborn. Light microscopy revealed adipocyte necrosis, a lymphohistiocytic infiltrate, and needle-shaped clefts within adipocytes and macrophages. Ultrastructurally, there were aggregations of electron-lucent spaces in the form of spindles and needles arranged in parallel within the altered adipocytes; macrophages surrounded these cells or their fragments and invaded the fat lobules. Enzyme histochemical staining, not previously reported in the literature, showed that acid phosphatase, leucine aminopeptidase, and indoxyl and non-specific esterases were present in the areas of fat necrosis.