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Biomedical subjects

T Sherman

Publications and source records attributed to T Sherman.

At least 19 recordsLinked to original sources
PubMed1994

Myocardial viability in asynergic regions subtended by occluded coronary arteries: relation to the status of collateral flow in patients with chronic coronary artery disease.

OBJECTIVES: This study aimed to determine whether angiographically visualized collateral vessels in patients with chronic coronary artery disease imply the presence of viable myocardium in asynergic regions subtended by completely occluded coronary arteries. BACKGROUND: Patients with chronic coronary artery disease who are being considered for revascularization frequently exhibit angiographically visualized collateral vessels to completely occluded coronary arteries supplying severely asynergic myocardial regions. However, little is known about the relation between angiographic collateral flow and myocardial viability in these patients. METHODS: We studied 42 patients with 78 completely occluded coronary arteries supplying asynergic territories. Angiographic collateral vessels were interpreted as absent (grade 1) in 14 patients, minimal (grade 2) in 27 and well developed (grade 3) in 37. Myocardial viability was determined with positron emission tomography using nitrogen-13 (N-13) ammonia and fluorine-18 (F-18) deoxyglucose for assessment of regional perfusion and glucose uptake, respectively. Positron emission tomographic patterns were interpreted as mismatch (perfusion defect with enhanced F-18 deoxyglucose uptake); transmural match (severe concordant reduction or absence of both perfusion and F-18 deoxyglucose uptake) or nontransmural match (mild to moderate concordant reduction of both perfusion and F-18 deoxyglucose uptake). RESULTS: There was no significant correlation (p = 0.14) between the severity of perfusion deficit assessed by positron emission tomography and the collateral grade. The extent of mismatch was unrelated to either the presence or the magnitude of collateral vessels. Conversely, with increasing collateral vessels from grade 1 to 3, the total extent of positron emission tomographic match remained similar, whereas the ratio of transmural to nontransmural match decreased. Myocardial viability was usually present in severely hypokinetic regions (82%). It was lower in akinetic-dyskinetic regions (49%). Of the 64 regions with angiographic collateral vessels, 37 (58%) (95% confidence interval [CI] 46% to 70%) showed positron emission tomographic mismatch. In contrast, 7 (50%) of 14 (95% CI 24% to 76%) regions without collateral vessels on angiography exhibited positron emission tomographic mismatch. The presence of angiographically visualized collateral vessels was a sensitive (84%) but not specific (21%) marker of viability. CONCLUSIONS: In patients with chronic coronary artery disease, angiographically visualized collateral vessels to asynergic myocardial regions subtended by occluded coronary arteries do not always imply the presence of viable myocardium, suggesting that revascularization may not always provide a functional benefit.

Adult↗
PubMed1994

Cognitive/neuropsychological studies of children with a schizophrenic disorder.

This article summarizes a series of cognitive/neuropsychological studies of children with schizophrenia. One set of studies, which surveyed a broad range of neuropsychological functions, revealed no evidence that children with schizophrenia are consistently impaired in sensory, perceptual, or language functions. Rather, the studies showed that children with schizophrenia performed poorly on tasks requiring sensory, perceptual, and language processing that made extensive demands on information-processing capacity. A second series of studies, which examined visual information processing by manipulating the processing demands of span of apprehension tasks, yielded similar findings. The key characteristic of tasks that elicit impaired performance in children with schizophrenia is that the task makes extensive demands on processing resources. This suggests that these children have limited information-processing capacity. Three hypotheses are proposed concerning the cognitive processes that are impaired in children with schizophrenia: (1) the cognitive processes that seem to be impaired in these children are part of a more general, hierarchically organized attention system; (2) the component processes of the system are subserved by different brain structures; and (3) the structures are part of a network that includes the frontal lobe and thalamus in interaction with the reticular activating system.

Adolescent↗
PubMed1992

Innovative desktop learning tools. Implications for rural hospitals and physicians.

Innovative methods of providing workplace education for health care professionals may be a key to the survival of rural hospitals in America. Such methods must overcome time, distance, cost and organizational constraints, and take into account the structure of the learning experience. The Texas Hospital Education and Research Foundation has recently been involved in two programs that tested new approaches to worker education using distance-learning strategies. The projects--resource sharing among rural directors of nursing and training for cancer tumor registrars--used computer-conferencing technology. A new model using existing satellite, audio-conferencing, and computer-based instruction augmented by computer conferencing is proposed. The Computer-Related Assisted Distance Learning Enhancement (CRADLE) model integrates existing technologies to provide education to health care workers at their desktop. The Cancer Learning Center (CLC) tested peer collaboration, the primary component of the model. The ultimate goal is to have the system available to all tumor registrars in Texas, and to secure funding to implement rural nursing and rural high-school health occupations education projects. Current projects from set-up through results are presented.

Computer Communication Networks↗
PubMed1992

Non-verbal communication skills of surgically treated children with infantile spasms.

The authors present preliminary findings on the effects of surgery on the development of early non-verbal social communication skills in eight children with intractable infantile spasms. After a mean follow-up of 15.2 months, there was no statistically significant change in the post-surgical non-verbal communication behavior of these children beyond the expected developmental change. Implications of these findings for the developmental impairment associated with infantile spasms are discussed.

Cerebral Cortex↗
PubMed1992

Early onset intractable seizures: nonverbal communication after hemispherectomy.

The nonverbal communication skills of 10 children (mean age = 44.2 months) who underwent hemispherectomy for early onset intractable seizures were tested before and after surgery. A within-group analysis suggests that the 10 seizure-free children used more nonverbal communication after a mean follow-up period of 11.2 months than before surgery. Young normal language age matches were available for the 4 older and higher functioning subjects in the sample. Before surgery, the surgical subjects used less requesting gestures than did the normal children. After surgery, these differences were no longer apparent. The patients also employed more gestures to focus an adult's attention on objects and events than language-age-matched normal children. The children who underwent left or right hemispherectomy used similar nonverbal communication behaviors. The study's findings suggest that children with early onset intractable seizures have impaired early social communication that improves to some extent after hemispherectomy.

Child, Preschool↗
PubMed1990

Information processing deficits of schizophrenic children with formal thought disorder.

The relations among formal thought disorder, the partial report span of apprehension task, the distractibility factor on the Wechsler Intelligence Scale for Children-Revised (WISC-R), and IQ scores were examined in 31 schizophrenic children, aged 7.4 to 12.5 years. The partial report span of apprehension scores of the schizophrenic children correlated significantly with their illogical thinking scores. Their scores on loose associations were significantly associated with the WISC-R distractibility factor score. The attention/information processing deficits that might underlie the clinical manifestations of illogical thinking and loose associations in childhood onset schizophrenia are discussed.

Attention↗
PubMed1987

Cryptogenic abscess of the liver. Evidence of underlying reticuloendothelial cell dysfunction.

Evidence of underlying liver disease and reticuloendothelial system dysfunction was sought in five adults with histories of idiopathic or "cryptogenic" liver abscess. Although no evidence of underlying liver disease was obtained (median follow-up, 3.4 years; range, 2.1 to 4.8 years), four of five individuals demonstrated a marked impairment in their ability to clear antibody-tagged erythrocytes from the systemic circulation. The results of this study suggest that patients who develop cryptogenic abscesses of the liver have an underlying reticuloendothelial cell defect that may predispose them to liver abscess formation.

Adolescent↗
PubMed1987

Nonverbal communication and play correlates of language development in autistic children.

The aim of this study was to determine the social and cognitive correlates of language acquisition in autistic children. Functional and symbolic play skills were shown to be associated with language abilities in a sample of young autistic children (mean CA 54.5 months), thereby replicating previous findings. Certain types of nonverbal communication skills were also shown to be significant correlates of language development in this group of autistic children. These involved the ability to use gestures to coordinate visual attention between social partners with respect to objects or events. The play and nonverbal communication variables were not significantly correlated, suggesting that these variables reflect independent psychological factors associated with language development in young autistic children.

Autistic Disorder↗
PubMed1987

Speech patterning of natural discourse of well and depressed mothers and their young children.

The speech behavior of 14 depressed and 18 nondepressed mothers during conversations with their 3-year-old children was examined in this study. Given the general motor retardation, reduced energy level, and social withdrawal of depressed individuals, the speech patterns of depressed mothers were predicted to differ from the speech patterns of well mothers. Depressed mothers vocalized less often and responded less quickly to the cessation of their children's speech than healthy mothers. However, in a mildly stressful situation (awaiting a doctor's visit) the depressed mothers, but not the healthy mothers, significantly increased their level of speech productivity. Children of the depressed mothers spoke less than children of healthy women, particularly while sitting and eating lunch with their mothers. The observed difference in the mothers' behaviors was interpreted as an indication that the 2 groups of children are exposed to very different patterns of socialization. The offspring of depressed women are being taught both to keep social interaction to a minimum and to be overreactive to even mild stresses. The differences in the children's behavior may indicate that already these 3-year-old children have learned to keep their interactions with their mother to a minimum. This manner of adaptation may have negative effects on the child's continued social, emotional, and cognitive development.

Adult↗
PubMed1986

Social interactions of autistic, mentally retarded and normal children and their caregivers.

The social interactions of young autistic children and their caregivers were contrasted to interactions involving normal and mentally retarded controls. The autistic children displayed a much lower frequency of attention sharing behaviors, such as pointing to or showing objects. Alternatively, the autistic children directed as much looking, vocalizing and proximity behaviors toward their caregivers as did the other groups. Thus, although the autistic children did not show a clear lack of responsiveness to their caregivers, they did display a significant deficit in indicating behaviors during child-caregiver interaction.

Attention↗
PubMed1986

Defining the social deficits of autism: the contribution of non-verbal communication measures.

Young autistic children were compared to normal and control samples on measures of non-verbal communication skills and object play skills. Deficits in non-verbal indicating behaviors best discriminated the children diagnosed as autistic from the other groups. Although the autistic children also exhibited deficits in object play behavior, these deficits did not add appreciably to the discriminant function based on the non-verbal communication behaviors. These results suggest that a deficit in the development of non-verbal indicating behaviors is a significant characteristic of young children who receive the diagnosis of autism.

Autistic Disorder↗
PubMed1985

Pulsed ultraviolet lasers and the potential for safe laser angioplasty.

Endoscopic laser ablation of atheroma using continuous wave lasers is limited by imprecise control of thermal ablation, resulting in a crater that expands in width and depth, with thermal damage to adjacent normal tissue. We compared the gross and histologic effects of pulsed 308 mm excimer irradiation to continuous-wave Nd:YAG and Argon Ion laser irradiation, and pulsed 1,060 nm, 532 nm, 355 nm, and 266 nm laser irradiation in 205 atherosclerotic aortic segments. In contrast to the continuous-wave Nd: YAG, Argon Ion, and pulsed 1,060 nm, 532 nm, and 355 nm laser irradiation, which produced gross and histologic evidence of uncontrolled ablation, the 308 nm and 266 nm pulsed lasers induced incisions that conformed precisely to the beam configuration without gross evidence of thermal injury. The incision edges from these two lasers were histologically smooth and comparable to a scalpel incision. Our histologic findings suggest that rapid, precise endoscopic ablation of vascular and nonvascular tissue can be performed at these shorter pulsed wavelengths with very high precision with relatively little damage or risk to adjacent tissue.

Aorta, Abdominal↗
PubMed1985

Delineation of peripheral and coronary detail by intraoperative angioscopy.

In this study, the development of intraoperative angioscopy, the value of the information obtained, and the problems encountered with the procedure are reported. Eight angioscopes, 1.5 to 2.8 mm in diameter, with a line resolution of greater than 0.4 mm at 5 mm, were used. One-hundred ten angioscopic investigations were performed in 46 patients; 24 at peripheral bypass surgery and 22 at coronary artery bypass surgery. These included 68 arteries, 28 new anastomoses, six old grafts, five laser angioplasties, and three in situ vein grafts. The most important finding was that angioscopic data provide information not available from probes or angiography. Angioscopic findings were responsible for a change in surgical procedures in 12 patients (26%) including three anastomotic revisions, three alterations in graft site placement, and two repeat thrombectomies. The most significant technical problems were lack of steerability and insufficient irrigation, which resulted in poor angiographic images. Further technical development is necessary before routine intraoperative angioscopy is practical. Nevertheless, if these problems are resolved, angioscopy will provide unique, high-resolution information which can directly alter surgical therapy.

Angioplasty, Balloon↗
PubMed1985

Categorization skills in infants.

The prototypical category-learning experiences with which infants are confronted are ones in which they have had prior experience with and have clearly noted the differences among a set of objects. Their task, then, is to notice also the similarities among the objects and to form a category based on these similarities. The goals of the current experiments were to create a laboratory situation in which it was clear that 10-month-old infants were distinguishing one category exemplar from another, and then to determine the structure of the category representation the infants developed under these learning conditions. A set of artificially created face stimuli was used in which the mean and modal prototypes were distinct. The infants' performance could not be explained by the context theory; they appear to have retained a count of the feature values observed during study. These data give support to the claim that prior to language, infants have available strategies for abstracting category-level information from their perceptual experiences with discriminable objects and events.

Attention↗
PubMed1984

Studies of visual information processing in schizophrenic children.

11 children meeting DSM III criteria for schizophrenia (mean age approximately 12 years), a group of normal children matched in mean mental age to the schizophrenic children, and a group of younger normal children (mean age 6.6 years) were administered a series of visual information-processing tasks in order to isolate core information-processing impairments in childhood onset schizophrenia. In Experiment 1, the schizophrenic children showed impairment relative to the MA-matched normals and performed at the level of the younger normal children on a forced-choice partial-report version of the span-of-apprehension task. Previous research has shown that this task is sensitive to dysfunction in both actively and partially recovered schizophrenic adults as well as a subset of foster children at risk for schizophrenia. Experiment 2 delimited the source of the information-processing impairment in schizophrenic children by ruling out a number of possible causes of impairment and suggesting that schizophrenic children use the same information-acquisition strategies as MA-matched children but less efficiently. Experiment 3 revealed that, consistent with the previous research, the schizophrenic children were comparable with the MA-matched controls on a full-report span-of-apprehension task that placed heavy demands on iconic and short-term memory. Both the schizophrenic and MA-matched normals performed significantly better than the younger normal children. Taken collectively, the results of the three experiments suggest that all groups of children engaged in a serial information-processing strategy while performing on the partial-report version of the span-of-apprehension task. The differential impairment of the schizophrenic children on the partial-report versions but not the full-report version of the span-of-apprehension task seems to reflect inefficiencies in controlled attentional processes that normally develop during middle childhood.

Attention↗