Differences between mentally retarded and nonretarded persons' efficiency of auditory sentence processing

Mentally retarded adolescents and MA-matched nonretarded children participated in three experiments designed to examine differences in language-processing efficiency. A compressed speech technique was used in Experiments 1 and 2. Experiment 3 relied on a sentence-picture verification procedure. Our results suggest that retarded and nonretarded individuals differ in the speed with which they are able to execute the semantic-analytic processes but not necessarily the phonological encoding processes that are involved in auditory language comprehension. In addition, the data suggest a possible group difference in the quality of the semantic representation encoded during sentence processing.     

Radiation dose reduction during hysterosalpingography: an application of scanning-beam digital radiography

Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.     

Development of the student placement evaluation form: A tool for assessing student fieldwork performance

Evaluation of students undertaking fieldwork education placements is a critical process in the health professions. As training programs and practice evolve, systems for assessing students need to be reviewed and updated constantly. In 1995, staff of the occupational therapy training program at the University of Queensland, Australia decided to develop a new tool for assessing student fieldwork performance. Using an action research methodology, a team developed the Student Placement Evaluation Form, a flexible and comprehensive criterion-referenced evaluation tool. The present paper examines action research as an appropriate methodology for considering real-life organisational problems in a systematic and participatory manner. The action research cycles undertaken, including preliminary information gathering, tool development, trial stages and current use of the tool, are detailed in the report. Current and future development of the tool is also described.     

Enamel loss associated with orthodontic adhesive removal on teeth with white spot lesions: an in vitro study.

Teeth with white spot lesions (WSL) might be more prone to enamel loss during bracket debonding. This in vitro study compared enamel loss from teeth with (n = 14) and without (n = 14) WSL after polishing with low-speed finishing burs or disks (Sof-Lex, 3M ESPE, St Paul, Minn). Debonded surfaces were analyzed with a contact stylus profilometer, and digitized data were compared with baseline readings by using AnSur NT software (Regents, University of Minnesota, Minneapolis, Minn). Specimen surfaces were also examined with a scanning electron microscope. Two-way analysis of variance was performed to analyze the data. In teeth without WSL, the volume losses were 0.16 mm(3) for the bur group and 0.10 mm(3) for the disk group; the mean maximum depths were 47.7 microm for the bur group and 54.3 microm for the disk group. In teeth with WSL, the volume losses were 0.06 and 0.17 mm(3), and the mean maximum depths were 35.1 and 48.7 microm for the bur and disk groups, respectively. There were no significant differences in enamel loss between the 2 groups of teeth without WSL (P =.12). However, in teeth with WSL, the burs removed less enamel than the disks (P = 0.006). Scanning electron microscope examination showed that any damage on the enamel surface was usually located in the cervical third of the teeth. On most specimens, even though tooth surfaces appeared resin-free to the naked eye, there were remnants of it. The differences between groups were so small that they might be clinically insignificant.     

Humoral control of water and electrolyte excretion during water restriction

The goals of the present study were twofold: first, to assess the renal excretory and hormonal responses to chronic water restriction in dogs whose sodium retaining mechanisms had been stimulated through dietary sodium (Na+) deprivation; second, to determine the mediator(s) of the natriuresis which was observed with water restriction in these sodium deprived dogs. Three groups of dogs maintained on a low Na+ diet (5 mEq/day) for two weeks underwent a three day period of water restriction. In normal, intact dogs Group 1 (N = 5), water restriction resulted in a significant increase in Na+ excretion with a net cumulative loss of 26.3 +/- 2.6 mEq over three days. The natriuresis was associated with a significant increase in plasma vasopressin (PAVP) (1.7 to 10.2 pg/mliter) and a significant fall in plasma aldosterone (PALDO) from the levels observed with Na+ restriction alone (24.9 to 12.4 ng/dliter). The natriuresis could not be explained by decreases in food intake as determined by control studies in four dogs. Group 2 (N = 6) dogs had a decrease in PALDO with water restriction that was prevented by means of continuous i.v. aldosterone infusion (6.0 micrograms/kg/day). Dogs in this group failed to demonstrate a natriuresis during three days of water restriction, despite the fact that PAVP rose from 3.3 +/- 0.8 to a peak level of 14.95 +/- 1.9 pg/mliter. Group 3 (N = 6) dogs underwent selective neurohypophysectomy, thus preventing the rise in PAVP during three days of water restriction. In this group, PALDO also remained unchanged from the Na+ deprived level during water restriction, and no natriuresis was observed. We conclude: 1) that the natriuresis which occurs with water restriction is a potent physiological response that occurs even in the Na+ restricted state; and 2) this natriuresis can be explained by a fall in PALDO and not the rise in PAVP.     

Merkel Cell Carcinoma Arising from the Subcutaneous Fat of the Arm with Intact Skin

BACKGROUND: Merkel cell carcinoma is a rare malignant neuroendocrine neoplasm characteristically arising from the dermis of sunlight-exposed skin. It rarely arises outside the skin. OBJECTIVE: We present a patient with primary Merkel cell carcinoma arising from subcutaneous fat, with no involvement of the overlying skin. We describe the clinical manifestations and magnetic resonance imaging (MRI) findings. METHODS: We report a 63-year-old woman with a primary lesion of Merkel cell carcinoma that arose from the subcutaneous fat layer of the left arm. The lesion presented as a subcutaneous nodule with intact overlying skin. MRI showed that the nodular lesion was located entirely in the subcutaneous fat layer, with no involvement of the dermis. Peritumoral infiltration around the lesion and enlarged lymph nodes deep to the lesion were noted. The patient received wide excision of the lesion with dissection of the regional lymph nodes and adjuvant radiotherapy and chemotherapy. RESULTS: Histopathologic examination confirmed the diagnosis of Merkel cell carcinoma with local lymphatic metastasis, and the lesion was completely located in the subcutaneous fat, with no involvement of the dermis. These findings were well correlated with MRI findings. CONCLUSION: Primary Merkel cell carcinoma may arise from the subcutaneous fat and present as an entirely subcutaneous lesion with intact skin. MRI is helpful to evaluate the local extension of the lesion and regional lymphatic metastasis.