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PubMed1979

[Oral manifestations of Letterer-Siwe disease. Clinical and histological study of lesions centered in the mouth of a infant with acute and disseminated histiocytosis X].

The clinical, radiological and histological aspects of acute histiocytosis X of Letterer-Siwe disease are reviewed after personal observation of such cases. In spite of many advanced hypotheses the etiopathogenesis of Histiocytosis X is wide open to research. The diagnosis became possible by the discovery of histiocyte cells of a special order, the X-bodies, under the E. M. Recent research allows a classification of Letterer-Siwe disease, Hand-Schüller-Christian disease, and the eosinophilic granuloma under the same nosologic grouping. Finally, the prognosis of the Letterer-Siwe disease-so far much in the dark-may be improved by a properly conducted therapy.

Bone and Bones↗
PubMed1978

[Abt-Letterer-Siwe disease. Diagnosis and therapy (author's transl)].

An infant with Abt-Letterer-Siwe disease is reported. The diagnosis was established by histopathology and electron microscopy.--2. Complete remission was achieved with vinblastine and prednisone. Treatment, however, in these cases has to be continued for a longer period of time.--3. Early diagnosis and therapy are important because Abt-Letterer-Siwe disease is lethal in most untreated cases. With adequate chemotherapy, long remissions or cures can be expected in about 70% of the cases.--4. In Abt-Letterer-Siwe disease, the racket-like Langerhans cell granules are found by electron microscopy within the specific infiltrating cells. The demonstration of these organells allows the unequivocal diagnosis in cases with uncharacteristic clinical or histopathological appearance. The same structures are characteristic of Hand-Schüller-Christian disease and of eosinophilic granuloma. The electron microscopic findings confirm the grouping of these three diseases together as "histiocytosis X".

Biopsy↗
PubMed1979

Visual persistence and code selection in short-term memory for letters.

Four experiments were conducted to examine temporal changes in visual and name codes and the relationship between them. Unlike earlier studies, the design included (a) several levels of visual similarity in addition to the conventional same case and different case conditions and (b) physical- as well as name-match tasks to provide direct evidence about subjects' retention of form information. The main results were as follows: First, the presence of multiple typefonts in the stimulus set does not eliminate convergence between the reaction time functions for the physical- and name-match conditions in a name-match task. Second, inclusion of a physical-match task, requiring subjects to retain form information, does not necessarily eliminate convergence in a primary, name-match task. When the secondary task does reduce convergence, however, the results suggest that it does this through its effect on the name-match function rather than on the physical-match function. Third, apart from difficulties with within-cluster typefont combinations, particularly at long interstimulus intervals, subjects can generally retain and use reliable information about letter form over the ISI range (.5--4.0 sec) used in the experiments. The results were thought to be consistent with the conclusion that convergence results from a combination of (a) a nonoptional decrease in the accessibility of the visual code as a function of increasing ISI and (b) an optional increase in the accessibility of the name code. Under ISI conditions at least, convergence cannot be attributed to either generation of a visual code of the alternative form of the target letter or to the absence of relevant form information.

Discrimination Learning↗
PubMed1979

Studies of letter identification using qualitative error analysis: effects of speed stress, tachistoscopic presentation, and word context.

In Experiment 1 subjects named letters under a response deadline chosen so that an appreciable number of errors would be produced. The stimulus confusions were analyzed via the same mathematical models of stimulus recognition that have been applied to the confusion matrices generated in tachistoscopic experiments. Both the Luce choice model and the informed guessing model (a new model having a simple and elegant process interpretation) provided excellent fits to the data. The parameter values of the informed guessing model changed in logical and interpretable ways with changes in the response deadline. In Experiment 2 a direct comparison was made of the types of errors produced in the data-limited tachistoscopic situation and the resource-limited response deadline situation. It was found that, relative to the response deadline task, identification in the tachistoscopic task is much more likely to be based on partial information. In Experiments 3 and 4 the same research methodology was applied to the problem of the effect of a word context on letter perception. The methodology allowed this problem to be addressed in the context of both response deadline and tachistoscopic tasks. Several advantages of the methodology for investigating other issues of interest to cognitive psychologists are discussed.

Discrimination Learning↗
PubMed1978

Letterer-Siwe disease. Presentation as an otologic problem.

Letterer-Siwe disease is one of the three clinical syndromes that are collectively known as histiocytosis X. This is the most aggressive form of histiocytosis and is frequently fatal. Recently, however, early treatment with chemotherapeutic agents and steroids has prolonged survival and has even resulted in remission of a number of cases. This paper draws attention to a persistent external otitis as an early symptom of Letterer-Siwe disease and identifies, histologically, involvement of the external auditory canal.

Child, Preschool↗
PubMed1979

Individual differences in visual discrimination of letters.

Research on the distinctive features of letters has been inconclusive. Investigators may have overlooked individual variations in their data which would have supported feature-extraction hypotheses but were concealed by analyses which averaged data into group means. Response latencies from a matching discrimination task with the 26 English capital letters were analyzed with INDSCAL, a multidimensional scaling procedure which weights individual contributions to a psychological space. Underlying a dimensions were linearity, curvature, angularity, and closure. The solution disclosed that individuals utilized these features differentially in the visual discriminations. The results suggest that future research in visual feature extraction will benefit from the examination of individual variations in the perceptual process.

Discrimination Learning↗
PubMed1979

Word context effects on letter recognition.

24 subjects were asked to determine whether a target letter was present in a tachistoscopically exposed word. The presence of the target was detected faster if the target was clarly sounded in the word, that is, the target G in the word TIGER was detected faster than the target G in the word RIGHT. This effect was strongest among subjects whose over-all response time was below the median value. This result was interpreted as evidence that (1) a word is recognized as a whole before its component parts are analyzed, (2) the transformation of the word from visual to acoustic code occurs before the analysis of the individual letters, and (3) individual differences in efficiency of target detection depend on a subject's over-all response time.

Adolescent↗
PubMed1978

[Notes on respiratory and cardiac pathology in an unpublished letter of Maurizio Bufalini].

An unpublished letter written by Maurizio Bufalini on 8th January 1820 describes a clinical case of considerable gravity characterized by asthma with pleural effusion and "dilatation of the vena cava". On this basis, the state of knowledge of asthma in that period, particularly in relation to heart diseases, is reviewed. Following a careful examination of the letter, the possibility that M. Bufalini may have been a forerunner of the modern concept of cor pulmonale is suggested.

Asthma↗
PubMed1979

[Goethe's personal testimony on his work with "organic creatures". II. Letters (1776-1817)].

Once more following the Sophien-Ausgabe of Weimar, Author gives an extract from GOETHE's Letters to literati, scientists, and princes of his time, concerning notices on his employment about sciences without botany. The GOETHE's own words reflect his engagement better than any description from a second hand. Anatomists may take an especial interest in the letters No 1903 to HERDER and No 1904 to CHARLOTTE v. STEIN (both dated the March 27, 1784) which demonstrate the discoverer's mirth in finding out the human os intermaxillare.

Anatomy↗
PubMed1978

Retinal locus and the identification of tachistoscopically presented letters by retarded and nonretarded individuals.

Two-letter stimulus displays, differing in the magnitude of the horizontal spatial separation between the letters, were presented tachistoscopically to retarded and nonretarded persons. Assuming that the spatial separations are linearly related to retinal location, I derived an estimate of the stimulus-recognition threshold for each group by employing the method of constant stimuli. The data indicated a similar stimulus-recognition threshold and a similar decrement in the accuracy of responding as the stimulus separations increased. These findings suggested that reported differences in iconic memory between retarded and nonretarded individuals are most likely related to a postretinal stage of cognitive processing. Studies of iconic memory must take into account not only the influence of retinal locus but also the finding that, as the task becomes more difficult, retarded individuals may be less willing to respond.

Adult↗
PubMed2026

Understanding FDA's reasons for nonapproval: A systematic review of complete response letters in cell and gene therapy.

BACKGROUND AIMS: Cell and gene therapy products face unique regulatory challenges due to their biological complexity and the stringent expectations for manufacturing control, analytical testing, and clinical assessment. As the pipeline grows, understanding the drivers of FDA non‑approval is increasingly important for improving first‑cycle success and reducing development delays. In this study, we aimed to characterize the frequency and impact of refuse‑to‑file actions, major amendments, and complete response letters issued for biologics licensing applications; and to identify recurring patterns of deficiencies contributing to delayed approval. METHODS: Publicly available documents were extracted from the FDA website. Data from each approved cell and gene therapy product's regulatory history-including complete responses, major amendments, inspection timing, and cited deficiencies-were compiled and categorized across clinical, quality, and labeling domains. RESULTS: Analysis showed that informational deficiencies were common across modalities. Major amendments occurred in roughly half of applications, and complete responses had the most significant impact. Quality deficiencies appeared in all complete responses and were the predominant barrier, while clinical and labeling issues were less frequent but meaningful when present. CONCLUSION: Overall, these findings highlight the need for proactive FDA engagement, comprehensive readiness, and early inspection preparation to reduce regulatory risk and improve first cycle approval outcomes.

Humans↗
PubMed1978

The tachistoscopic recognition of letters under whole and partial report procedures as related to intelligence.

Investigations of the short-term memory task performance of retarded individuals have indicated that these individuals demonstrate a deficit in the mechanisms necessary for the acquisition, storage and/or retrieval of information. The present study examined the tachistoscopic letter recognition task performance of retarded and non-retarded individuals under a partial report and a whole report procedure. The results revealed that the retarded subjects did significantly more poorly relative to the non-retarded subjects under both procedures. The data were interpreted as indicating that the retarded subjects were inefficient in their strategy to make the simultaneous imput task manageable. Further, the data provided no support for the suggestion that a visual-to-auditory encoding process exists between iconic and short-term memory.

Adult↗
PubMed1979

Assessing consumer satisfaction from letters to the hospital.

A private psychiatric hospital's evaluation research unit assessed consumer satisfaction with service by analyzing the content of letters written in response to an invitation to comment on the hospital experience. Respondents included relatives and referring agents of those who had received treatment. They expressed greatest satisfication with the helpfulness of the hospital, general patient care, and the quality of the clinical staff. They expressed much dissatisfaction with communication, such as adequacy of information about patients' treatment and progress, and with management rules and procedures. The analysis showed that the older the patient and the fewer the number of previous hospitalizations, the greater was the satisfaction expressed.

Adult↗
PubMed1979

Visual-field asymmetries in letter recognition: evidence for asymmetry in early visual registration.

Two experiments on visual-field differences in tachistoscopic letter recognition are described. In the first, a bright pre-exposure field with a black fixation point was used, and the conventionally expected dominance of the right visual field was found. However, a large number of "blank" trials were observed, in which subjects completely failed to detect the presence of the flashed target. These "blanks" were themselves significantly asymmetric between visual fields, suggesting that asymmetry in early stimulus registration may play an unsuspected role in typical measures of cerebral asymmetry in recognition accuracy. This was confirmed in a second experiment in which use of dark pre-exposure fields eliminated "blanks" and led to higher over-all accuracy, with no visual-field differences. Implications for interpretation of laterality data with normal subjects are discussed.

Adult↗
PubMed1978

[Study on the effectiveness of the "Berlin Letters for Seniors (author's transl)].

The effectiveness of the "Berlin Letters for Seniors" (LFS) will be tested by a longitudinal study. Two Measurement Points (MP) are scheduled: 1976 and 1978. The total sample (N = 3000) comprehends two subsamples of receivers and non-receivers. Data were/will be collected by a questionnaire. A preliminary analysis of the MP I data shows that the two subsamples are comparable as to demographic variables and relevant attitudes; so they may serve as experimental versus control group. An examination of what the readers' concept of the LFS was like, proved that though reservation was recognizable approval prevails.

Aged↗
PubMedDate not supplied

Letterer-Siwe disease: report of case.

Initial oral symptoms of Letterer-Siwe disease reveal the importance of a dentist in establishing this diagnosis. This case is important in that the patient was five months old, at which time an early diagnosis was made and treatment had begun. Because most cases occur in young children, a high level of suspicion is necessary, because the oral manifestations and radiographic findings in children may often resemble the periapical, periodontal or cystic involvements frequently seen first by the dentist. The oral lesions were necrotic, hemorrhagic, and degenerative gingival tissues in the maxillary molar area. Loss of alveolar bone was evident. There was precocious eruption of seven primary teeth, which were slightly mobile. Dentally, prophylaxis and fluoride applications were supportive measures.

Bone Marrow↗