Anticipatory saccades in smooth pursuit: task effects and pursuit vector after saccades.

The dramatic improvement in smooth pursuit performance seen while analyzing the pursuit target has been ascribed to attention enhancement. With a periodic constant velocity target trajectory we ran a concurrent listening condition instead, to see if this mild distraction would degrade performance. Performance improved somewhat with the listening task, suggesting that displacing attentional effort from pursuit accuracy, rather than increasing it, brings better pursuit performance.

Age-related changes in brain: II. Positron emission tomography of frontal and temporal lobe glucose metabolism in normal subjects.

While many neuropsychological studies have demonstrated age-related performance alterations in tests thought to reflect frontal and temporal lobe function, there is little direct observation and comparison of these hypothesized brain changes in vivo. The cerebral glucose metabolism of frontal, temporal, and cerebellar regions was examined in 40 young (mean = 27.5 +/- 4.

Fine-needle aspiration cytologic diagnosis of lymphoepithelioma-like carcinoma of the lung. Report of two cases with immunohistochemical study.

Lymphoepithelioma is a term used to describe an undifferentiated carcinoma with prominent lymphoid infiltration in the nasopharynx. Recently, tumors with similar histology, designated as lymphoepithelioma-like carcinomas, have been described in other sites including the lung. The authors report two cases of pulmonary lymphoepithelioma-like carcinoma that were correctly diagnosed by fine-needle aspiration cytology.

Cytologic features of Kimura's disease in fine-needle aspirates. A study of eight cases.

Kimura's disease is a chronic inflammatory disorder of unknown etiology, presenting usually as painless subcutaneous swellings in the head and neck region or in the salivary glands. The cytologic features of fine-needle aspirates of eight cases of Kimura's disease were studied with reference to the histologic appearance of the subsequent surgical specimens. In the cytologic smears, the prominent feature was the presence of significant numbers of eosinophils in a background of lymphoid cells.

Hepatocellular carcinoma metastasizing to the brain and orbit: report of three cases.

Hepatocellular carcinoma rarely metastasizes to the brain or orbit. We report 3 clinically manifest examples, one of which occurred in a 13-yr-old boy. In 2 cases the intracranial metastasis was the initial presenting lesion.

Fine needle aspiration diagnosis of angiomyolipoma of the liver using a cell block with immunohistochemical study. A case report.

Fine needle aspiration diagnosis of hepatic angiomyolipoma has been reported rarely. Below we report one such case diagnosed by examination of a cell block. The presence of epithelioid smooth muscle cells, mature adipocytes, thick-walled vessels and extramedullary hematopoiesis established the diagnosis.

Principal axes and surface fitting methods for three-dimensional image registration.

We evaluated the effect of the image acquisition parameters on the accuracy of the principal axes and surface-fitting techniques for three-dimensional image registration. Using two types of phantom objects, MR brain image and a mathematically defined ellipsoid, we simulated pairs of scans with known acquisition parameters, including longitudinal coverage, magnitude of mis-registration, number of sections and section thickness. Both methods are sensitive to the systematic deformation of contours.

Biliary adenofibroma. A heretofore unrecognized benign biliary tumor of the liver.

Benign biliary tumors of the liver are uncommon. In this report, we describe a distinctive biliary tumor of 7-cm diameter occurring in the right lobe of the liver of a 74-year-old Chinese woman. The lesion, characterized by a complex tubulocystic nonmucin secreting biliary epithelial and an abundant fibroblastic stromal components, is distinct from other well-recognized biliary lesions.

Hippocampal atrophy in early Alzheimer's disease: anatomic specificity and validation.

We evaluated three groups of elderly individuals who were carefully screened to rule out clinically significant diseases that could affect cognition. They were matched for age and education. The groups included normals (N = 18), Alzheimer's Disease (AD) patients (N = 15), and minimally impaired individuals with memory complaints and impairments but who did not fulfill criteria for AD (N = 17).

Liver changes in reactive haemophagocytic syndrome.

Hepatomegaly and deranged liver functions are common findings in reactive haemophagocytic syndrome (RHS). We report the findings of 12 fatal cases of RHS in which histological materials of the liver are available for study. The underlying diseases of these patients included lymphoma/leukaemia (6 cases), disseminated undifferentiated carcinoma of the ovary (1 case), disseminated nasopharyngeal carcinoma complicated by tuberculosis (1 case), adenovirus pneumonia (1 case), pneumococcal pneumonia (1 case), typhoid fever (1 case), and possible drug intoxication (1 case).

Hepatic angiomyolipomas with a deceptive trabecular pattern and HMB-45 reactivity.

We report two cases of giant hepatic angiomyolipoma with a prominent component of epithelioid smooth muscle cells exhibiting a distinctive trabecular arrangement. These cells possessed peripherally vacuolated and centrally condensed hyaline cytoplasm. The nuclei were eccentrically placed in the cytoplasm.

Solitary necrotic nodule of the liver: parasitic origin?

Aims: To report further cases of solitary necrotic nodule of the liver and to study its nature.

Methods: Seven nodules were retrieved from 4000 necropsy and surgical liver specimens coming to light over the past five years. All of them satisfied the diagnostic criteria of solitary necrotic nodule: a solid lesion with a central necrotic core and a hyalinised fibrotic capsule containing elastic fibres.

Disseminated Penicillium marneffei infection in HIV-infected subject.

Penicillium marneffei is a rare human pathogen predominantly affecting residents of South-east Asia. We report four fatal cases from Hong Kong in human immunodeficiency virus-infected patients. The diagnosis was established by histological examination and confirmed by isolation of the fungus.

Saccades in pursuit eye tracking reflect motor attention processes.

A dysfunction of pursuit eye tracking in psychiatric patients has been well documented, but its cause has not. Recent speculation implicates a pathological disinhibition of saccades in these patients. However, great variability in tracking performance was found among nine normal subjects, and tracking quality improved in each when asked to perform a simple analysis of the tracking target: saccade counts and amplitudes decreased, as did a root-mean-square (RMS) error measure of overall tracking performance.

Endocrine cell hyperplasia of the uterine cervix. A precursor of neuroendocrine carcinoma of the cervix?

A 33-year-old woman who presented with vaginal bleeding was diagnosed to have neuroendocrine small cell carcinoma based on cervical smear and biopsy. Hysterectomy was performed, and a tumor measuring 5.5 X 2 mm was found at the squamocolumnar junction of the uterine cervix.

Reaction of the anionic acetylation agent methyl acetyl phosphate with D-3-hydroxybutyrate dehydrogenase.

Methyl acetyl phosphate is a competitive inhibitor of the reduction of acetoacetate by D-3-hydroxybutyrate dehydrogenase. The material also irreversibly inactivates the enzyme. The kinetics of the inactivation are consistent with methyl acetyl phosphate acetylating the conjugate base of a hydrogen bond donor.

The histological changes in the testis, epididymis and prostate gland of the red-bellied tree squirrel, Callosciurus erythraeus, during the growth and reproductive cycle.

The male reproductive glands of the red-bellied tree squirrel, Callosciurus erythraeus, in the infantile, and prepubertal males, as well as sexually functional, degenerating and redeveloping adults were studied histologically. In the infant, testes are characterized with solid seminiferous tubules filled with primordial germ cells and Sertoli cells. Interstitial cells are sparse.

A comparison of the effects of atenolol and metoprolol on attention.

Additional side-effects of two beta-blockers, atenolol (hydrophilic) and metoprolol (lipophilic), were measured in 18 normal male volunteers in a randomized double-blind placebo-controlled crossover study. A saccadic eye movement reaction time (RT) task, a manual RT version of the Stroop Colour-Word Task, the Span of Apprehension Task, and the Continuous Performance Task were presented on a graphics display screen. Standard cognitive effects were replicated on all measures.