Malignant endovascular papillary angioendothelioma. Cutaneous borderline tumor

Malignant endovascular papillary angioendothelioma, a rare but distinctive vascular tumor of childhood, was first described in 1969. It was termed malignant because of its mitotic activity, areas of necrosis, and demonstrated ability to metastasize to regional lymph nodes. Despite these features it had a uniformly good prognosis. We report an example of this lesion in a 6-year-old boy that does not show malignant histologic features. Based on its good long-term prognosis and variable histologic features, this lesion is better classified as a borderline vascular tumor.

Detection of herpes simplex infection in cytologic smears

We compare the results of direct immunofluorescence (IF) with cytology (Papanicolaou's stains) for diagnosis of herpes simplex infection. Thirty smears were examined. Yellow-green fluorescence was seen in 17 smears. Only eight of these smears had diagnostic cytology, and nine of the smears with positive fluorescence had none (four) to minimal (five) cytologic changes, suggesting that direct IF is a much more sensitive method for diagnosis of herpes simplex infection in cytologic smears.

Benign hepatocellular tumors in the young. A clinicopathologic spectrum

Hepatic tumors unassociated with cirrhosis were encountered in seven patients aged 10 to 19 years. Four patients had received androgens for aplastic anemia. Two patients had transfusional hemosiderosis. One patient had had a renal transplant 2 1/2 years ago. Two patients are alive at 2 3/4 and 2 1/2 years after surgical resections. Nodules were found at autopsy in the others. The tumors were well differentiated and, in the androgen-related cases, differed from the others in the following features: canalicular bile retention, mild nuclear atypia, and acinar formation. No mitoses, vascular invasion, or metastatic tumor were evident. The clinical setting was variable; different factors, including iron overload and androgen therapy, played a role in the development of tumor. Although the androgen-related cases showed mild cellular atypia, biologic evidence of malignancy was lacking as in most previous reports.

Effects of grinding and storage for one month on retention of vitamin A in premixes and mineral supplements

Tested standardized procedures for handling premixes and mineral supplements from time of sampling to time of analysis for vitamin A have not been developed, which could account for some unexplained inconsistent and low analytical results. Grinding premix samples and storing them in a freezer for one month had little effect on amount of vitamin A found, but there was a significant loss (about 10%) after storage for one month at room temperature. Results on replicated determinations of vitamin A in unground and ground mineral supplements and on effect of storage were somewhat more variable than for premixes, but only the loss (about 12%) during storage for one month at room temperature was significant.

Letter-by-letter reading: psychological descriptions of a neurological syndrome

Following a general description of the characteristics of letter-by-letter reading and a summary of previous explanations of this reading deficit in both neurological and psychological models, four single-case studies of patients with this syndrome are presented. One central topic, addressed by experimental investigation, concerns comprehension of written words. Despite the use of multiple techniques, no evidence was obtained for the hypothesis that comprehension of a word could occur prior to or in the absence of the letter-by-letter analysis required for oral reading. It appears that these patients must do sequential letter identification of a word in order both to understand it and to report it. A second central topic, addressed through analysis of reading errors, concerns procedures for word recognition. Two of the four patients showed a “pure” letter-by-letter syndrome, with no difficulty in word recognition once the component letters had been identified. For the other two patients, an additional lexical deficit often prevented a correctly identified sequence of letters from achieving recognition as the correct word. Alternative interpretations of these patterns are discussed in terms of a process model.

Terminal deoxynucleotidyl transferase expression in acute non-lymphoid leukaemia: an analysis by immunofluorescence

Indirect immunofluorescence for terminal transferase enzyme (TdT) was used to study the blasts of 64 patients with acute non-lymphoid leukaemia (ANLL). In 32 patients no TdT positive cells were seen. In 19 cases a small subpopulation of cells expressing TdT was detected; these constituted up to 5% of total nucleated cells, and it was not clear whether these TdT positive cells were part of the leukaemic process or represented residual normal bone marrow lymphoid cells. The remaining 13 patients had TdT positive cells accounting for 7-90% of the total. In two of these cases TdT was expressed on blasts with myeloid features, representing an aberrant expression of TdT by myeloid cells; in contrast, in three cases mixed populations of TdT positive lymphoid blasts and TdT negative myeloid blasts were observed. In the remaining cases it was not possible to determine whether the TdT positive cells had definite lymphoid or myeloid features. Cytogenetic analysis showed no evidence of the Philadelphia chromosome. Response to treatment was assessed in 11 of the 13 patients. Only one patient remitted with the initial choice of therapy (DAT); four failed to respond to initial regimes of vincristine and prednisone (V & P) while the other five patients did not respond to myelotoxic combinations (DAT). Only one patient subsequently entered complete remission on second line therapy (V & P). This group of patients with TdT+ ANLL had a particularly bad prognosis, and appeared to differ from cases of TdT positive acute undifferentiated leukaemia, which often respond to V & P therapy.

The histones of yeast. The isolation and partial structure of the core histones

The four core histones of yeast chromatin have been isolated. Amino acid composition, electrophoretic mobility and partial sequences identify one variant each of the histones H3 and H4, whereas the histones H2A and H2B are represented by two variants each. In the yeast histones H3 and H4 7% of the residues, positioned in the partial sequences vary if compared with the corresponding histones from higher plants and animals, for the histones H2A and H2B from yeast this figure is 20%.

Hemispheric differences in processing visual patterns

The dichotomies verbal/visuospatial, serial/parallel and analytic/holistic are reviewed with respect to differences in hemispheric processing. A number of experimental parameters may be varied in such tasks, and together with certain frequently-occurring weaknesses of experimental design may account for the often discrepant results hitherto reported. The above factors are systematically reviewed, and three further experiments are reported which attempt to fill in the missing designs. Further evidence is given in support of the hypothesis that right-hemisphere superiority is most apparent in processes leading to identity matching. It is quantitative rather than qualitative, and may depend upon operations on the entire gestalt, such as holistic matching, mental rotation, reflection, distortion, etc., rather than, e.g., simultaneous (parallel) processing of discretely analysed or isolated features or elements. On the other hand left-hemisphere involvement in visuospatial processing is thought to reflect analysis of the configuration into its separable components; such processing may be either serial or parallel, and may frequently lead to a judgement different.

The perception and identification of mirror-reversed patterns

Many species have difficulty in discriminating between mirror-image stimuli, especially those about a vertical axis, and when identificatory rather than purely perceptual processes are involved. Various theories are reviewed. In two experiments involving same-different judgments for pairs of stimuli, triangles or semicircles, these were simultaneously presented either unilaterally or bilaterally, and in mirror or aligned orientations with respect to each other. Mirror oriented stimuli presented to opposite cerebral hemispheres were no more readily matched than those possessing the same orientations (aligned), thus suggesting that at the perceptual level there is no interaction between mirror-corresponding points in the two visual cortices. Foreknowledge of stimulus orientations failed differentially to affect the findings. Two other studies were performed involving manual identification of single letters, correct or mirror oriented, in either visual field. Here, for most subjects, mirror reversal proved either less disruptive or even advantageous when in the visual field which is normally inferior with correctly oriented material. It was concluded that mirror-image confusion at the level of memory is almost certainly a consequence of reversed coding, in some form, in the opposite sides of the brain. A number of incidental findings were made with respect to visual field effects.

Differential hemispheric mediation of nonverbal visual stimuli

Studies employing schematic faces of three features explored the role of the left hemisphere as an analytic processor in difficult discriminations and the role of the right hemisphere in easy gestalt matches. In a discrimination task, the successively presented members of a stimulus pair differed in all three features. When both stimuli went to the same visual field there was a Visual Field X Judgments interaction; judgments same were processed faster in the left visual field. When a test stimulus differing on all three features from a previously memorized target face was matched to the latter, both judgments same and different were made faster for stimuli in the left visual field. However, when the test stimulus and the memory items differed on only one feature the right field proved superior for both judgments same and different.

Diffrential hemispheric mediation of nonverbal visual stimuli

Studies employing schematic faces of three features explored the role of the left hemisphere as an analytic processor in difficult discriminations and the role of the right hemisphere in easy gestalt matches. In a discrimination task, the successively presented members of a stimulus pair differed in all three features. When both stimuli went to the same visual field there was a Visual Field X Judgments interaction; judgments same were processed faster in the left visual field. When a test stimulus differing on all three features from a previously memorized target face was matched to the latter, both judgments same and different were made faster for stimuli in the left visual field. However, when the test stimulus and the memory items differed on only one feature the right field proved superior for both judgments same and different.