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Biomedical subjects

S Fishman

Publications and source records attributed to S Fishman.

At least 37 records · Page 2Linked to original sources
PubMed1999

Human brain activation under controlled thermal stimulation and habituation to noxious heat: an fMRI study.

Brain activity was studied with functional magnetic resonance imaging (fMRI) following thermal stimulation. Two groups (n = 6/group) of human male volunteers were given up to four noxious (46 degrees C) and four non-noxious (41 degrees C) stimuli. In the 46 degrees C experiment, positive signal changes were found in the frontal gyri, anterior and posterior cingulate gyrus, thalamus, motor cortex, somatosensory cortex (SI and SII), supplementary motor area, insula, and cerebellum. Low-level negative signal changes appeared in the amygdala and hypothalamus. All regions activated by 46 degrees C were also activated by 41 degrees C. However, except for SI and thalamus, significantly more activation was observed for the 46 degrees C stimulus. A significant attenuation of the signal change was observed by the third stimulus for the 46 degrees C, but not for 41 degrees C experiment. Similar findings were replicated in the second group. These fMRI findings specify differences between somatosensory and pain sensation and suggest a number of rich avenues for future research.

Adult↗
PubMed1999

Elevated serum vascular endothelial growth factor in children and young adults with Crohn's disease.

Vascular endothelial growth factor (VEGF) is a cytokine released by fibroblasts, epithelial cells, and leukocytes that potentiates vascular permeability and growth of new capillaries. Because of these multiple effects, VEGF has been postulated to play a role in the pathogenesis of autoimmune disease, as well as in wound healing. We hypothesized that VEGF was potentially important in mediating the vascular permeability and angiogenesis seen in Crohn's disease, and therefore that VEGF would be increased in the serum of children with Crohn's disease. Serum was obtained from 73 children and young adults with Crohn's disease, 47 with ulcerative colitis, and 29 controls. VEGF levels were measured by enzyme-linked immunosorbent assay. Mean VEGF levels were significantly higher in patients with Crohn's disease (436.4 +/- 37.2 pg/ml) than in ulcerative colitis (306 +/- 41.1 pg/ml) or control (167.8 +/- 29.6 pg/ml) patients. Serum VEGF also correlated significantly with disease activity, being elevated in patients with moderate/severe Crohn's disease and ulcerative colitis. We conclude that serum VEGF is released by inflamed tissues in children with Crohn's disease. This multifunctional cytokine could promote inflammation by increasing vascular permeability or promote wound healing by mediating capillary growth.

Adolescent↗
PubMed1999

Nissen fundoplication and Boix-Ochoa antireflux procedure: comparison between two surgical techniques in the treatment of gastroesophageal reflux in children.

Over a period of 19 years an antireflux procedure was performed for gastroesophageal reflux in 59 children. Thirty-two patients underwent Nissen fundoplication and 27 children underwent the Boix-Ochoa antireflux procedure. Six patients died between two and 15 months post surgery of unrelated causes. Follow-up period from six months to 18 years was available in 45 (85%) of the surviving patients. This report summarizes the complications and long-term results with the two surgical procedures and their comparisons. The follow-up evaluation included parental interview and physical examination. Upper GI series and pH monitoring were performed only in children with signs and symptoms of recurrent GER or other post-operative complications. At follow-up with a mean period of 8.7 years following Nissen fundoplication, 87.5% showed good results without any residual symptoms. However, the overall complication rate was as high as 50%. Following the Boix-Ochoa antireflux procedure, 17 (81%) children showed excellent results while four children had recurrent GER. This occurred in two neurologically impaired children and two patients following esophageal atresia repair. No other post-operative complications were encountered with the Boix-Ochoa antireflux procedure. In our experience, the Boix-Ochoa antireflux procedure should be the procedure of choice in the surgical treatment of GER in otherwise normal children while the Nissen fundoplication is preferable in neurologically impaired children and in patients with GER following esophageal atresia repair.

Female↗
PubMed1999

Persistence of self in advanced Alzheimer's disease.

PURPOSE: To determine if evidence of the persistence of a sense of self or personal identity could be found in people in the middle and late stages of Alzheimer's disease. The theme of diminishing self pervades both the popular and professional literature on Alzheimer's disease. DESIGN: Qualitative using conversational analysis. The purposive sample was 23 residents of two urban nursing homes in the southeastern United States who were in the middle and late stages of Alzheimer's disease. Their mean Mini-Mental State examination score was 10.65. Nineteen subjects were women, four were men in this 1993-1997 study. METHODS: Analysis of 45 conversations lasting 30 minutes with nursing home residents with a diagnosis of probable Alzheimer's disease. Use of the first person indexical and other evidence, such as awareness and reactions to the changes that had taken place, in support of and counter to the notion of persistence of self, were sought in conversational analysis. FINDINGS: Respondents used the first person indexical frequently, freely, and coherently. Evidence was also present that participants were aware of their cognitive changes. Many struggled to provide an explanation, but none mentioned Alzheimer's disease. CONCLUSIONS: Evidence suggests the persistence of awareness of self into the middle and late stages of Alzheimer's disease. Failure to recognize the continuing awareness of self and the human experience of the person in the middle and late stages can lead to task-oriented care and low expectations for therapeutic interventions. The bafflement noted in respondents suggests that people should be told their diagnosis and offered an explanation of what this diagnosis means.

Alzheimer Disease↗
PubMed1998

Acute plasticity in the human somatosensory cortex following amputation.

We studied a patient after amputation of an arm and found that in less than 24 h stimuli applied on the ipsilateral face were referred in a precise, topographically organized, modality-specific manner to distinct points on the phantom. Functional magnetic resonance imaging (fMRI) performed one month later showed that brush-evoked activity in the brain demonstrates objective signal changes which correlate with perceptual changes in the phantom hand. This finding in humans corresponds to the observations of immediate plasticity in cortical pathways described in animals, including primates. The results suggest that reorganization of sensory pathways occurs very soon after amputation in humans, potentially due to the unmasking of ordinarily silent inputs rather than sprouting of new axon terminals.

Adult↗
PubMed1998

The expression of MDP-1, a component of Drosophila embryonic basement membranes, is modulated by apoptotic cell death.

Using a novel monoclonal antibody we have studied the expression of a large proteoglycan-type molecule in Drosophila embryos. This molecule is secreted exclusively by migratory, embryonic hemocytes/macrophages and was therefore named MDP-1 for Macrophage-Derived Proteoglycan-1. Expression of MDP-1 begins late during hemocyte differentiation, after these cells have left their birthplace in the head mesoderm. At this time, macrophages are engaged in extracellular matrix deposition and the phagocytosis of cell debris generated by apoptotic events in various parts of the embryo, in particular from the developing central nervous system. Embryos deficient for programmed cell death display a greatly reduced amount of MDP-1 deposition in tissues that normally undergo morphogenetic cell death. This suggests a regulatory role for apoptosis in the terminal differentiation of Drosophila hemocytes. MDP-1 is initially deposited around the developing central nervous system and is later found in basement membrane structures surrounding various other organs, such as the gut, Malpighian tubules and part of the tracheal system. The temporal and localized deposition of MDP-1 suggests that it may play a role in delineating the central nervous system structure during axonogenesis and may participate in the formation of a functional 'blood-brain barrier' in Drosophila.

Animals↗
PubMed1997

Communicating with individuals with Alzheimer's disease: examination of recommended strategies.

Meaningful conversation with individuals in the later stages of Alzheimer's disease (AD) has been considered difficult if not impossible. Limiting communication to simple concrete subjects and closed-ended questions is frequently recommended. Thirty-five 30 minute conversations with individuals with advanced AD (mean Mini-Mental State Examination [MMSE] = 10) were transcribed and the interactions examined. No significant differences in length or relevance of response by type of question was found indicating that subjects were able to respond to open-ended questions. Use of broad opening statements or questions, establishing commonalities, speaking as equals, and sharing of self-facilitated expression of feeling; recognizing themes with salience for the individual helped to maintain the discussion.

Affect↗
PubMed1994

Symptoms of patients with silent ischemia as detected by thallium stress testing.

This study was undertaken to determine whether patients with silent ischemia (SI) (a positive thallium stress test without chest pain) have nonchest-pain symptoms that might serve as "anginal equivalents." Two hundred ninety-four individuals on completing a stress test were requested to score ten symptoms on a questionnaire (0 absent; 3 severe). Forty-three with a positive test had pains (chest, back, arm, and/or jaw) (no SI), whereas 93 with a positive test did not (SI). Patients with SI and patients without SI did not differ as to age, gender, or clinical features (including presence of diabetes or a history of myocardial infarction), but patients with SI were less likely to report a history of effort-related chest pains. Patients with SI exercised longer and had a higher peak heart rate. Patients were comparable with respect to myocardial ischemia (ST segment depression, double product, thallium lung uptake, and positive thallium scintigrams) and severity of coronary disease. Patients with SI complained less of weakness (p < 0.02) and tended to have lower overall symptom scores (4.2 +/- 0.3 vs 5.4 +/- 0.6), but breathlessness was comparable for both groups. On multivariate analysis, no nonanginal symptom was associated with SI. Only absence of a history of chest pain with activity and longer exercise time were related to SI. Patients with SI have similar clinical features as those with angina but tend to be less symptomatic with myocardial ischemia even for symptoms other than chest pain.

Exercise Test↗
PubMed1993

Meconium testing for cocaine metabolite: prevalence, perceptions, and pitfalls.

OBJECTIVES: We determined the prevalence of prenatal cocaine use in a racially mixed sample of urban and suburban mothers and correlated its use with maternal demographics and newborn measurements. STUDY DESIGN: Meconium from 621 consecutive newborns delivered at two university-affiliated urban hospitals were assayed for benzoylecgonine. Maternal and infant characteristics were linked anonymously with the results. Statistical analysis included t test, Fisher's exact test, Duncan's multiple range analysis, and analysis of covariance, with a value of p < 0.05 considered significant. RESULTS: We found that 3.4% of meconium samples had benzoylecgonine levels exceeding 0.1 micrograms/ml. Its presence was statistically correlated with maternal and neonatal characteristics. A nurse's opinion of cocaine use was correct 22% of the time. CONCLUSIONS: Prenatal cocaine use was statistically associated with multiparity, multigravidity, late-onset and clinic-based prenatal care, public assistance, nonwhite race, and low academic achievement. A nurse's opinion was a poor predictor of maternal cocaine use. Cocaine-exposed infants were significantly smaller, and this correlated best with nonwhite background.

Birth Weight↗