Biomedical subjects
Publications and source records attributed to E Sobel.
The case history of a 19-year-old female with left ankle pain of 18 months' duration is presented. The reader is encouraged to make his or her own diagnosis after reviewing the history, laboratory values, and imaging. The final diagnosis with a full explanation and differential diagnosis will follow.
First-day thallium-201 myocardial perfusion scans and technetium-99m RBC gated scintiangiography were performed during the initial clinical and prognostic evaluation of 69 patients with suspected acute myocardial infarction. Patients were monitored for clinical course, diagnosis confirmation, and use of specialty services (cardiac catheterization, percutaneous balloon angioplasty, and cardiac surgery) during hospitalization. Myocardial infarction, confirmed in 20 patients, was associated with significantly more left ventricular dilatation, lower ejection fractions, lower peak left ventricular filling rates, wall motion abnormalities, and thallium-201 perfusion defects than nonmyocardial infarction patients. Among all patients, left ventricular dilatation carried a relative risk of myocardial infarction of 5.8; low ejection fraction and right ventricular dilatation were strongly associated with myocardial infarction. A logistic model for congestive heart failure included: left ventricular dilation, lower mean left ventricular filling rates and time to peak filling rates, and abnormal thallium-201 lung:heart uptakes. Among nonmyocardial infarction patients, subsequent cardiac catheterization was predicted by the presence of anterior thallium-201 perfusion defects, Killip functional class II-III, and ischemia on ECG. These findings suggest that early detection of myocardial perfusion defects and cardiac dysfunction by radionuclide scans enhances initial evaluation of suspected acute myocardial infarction patients. Additional studies are needed to confirm these findings.
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We conducted a case-control study of the possible association of occupations with likely exposure to electromagnetic fields and Alzheimer's disease (AD) with patients from the Alzheimer Disease Treatment and Diagnostic Center, Rancho Los Amigos Medical Center, Downey, CA. Patients with definite or probable AD were the case subjects (86 male, 240 female). Patients with cognitive impairment/dementia other than vascular dementia were control subjects (76 male, 76 female). The study was limited to patients who were at least age 65 at the time of their first examination at Rancho Los Amigos. The odds ratio for both sexes combined was adjusted for sex, education, and age at onset. The odds ratio for males was adjusted only for age at onset, and the odds ratio for females was adjusted for both education and age at onset. The adjusted odds ratio for both sexes was 3.93 (p = 0.006), 95% CI = (1.5 to 10.6). For males the adjusted odds ratio was 4.90 (p = 0.01), 95% CI = (1.3 to 7.9), and for females the adjusted odds ratio was 3.40 (p = 0.10), 95% CI = (0.8 to 16.0). These results are consistent with previous findings regarding the hypothesis that electromagnetic field exposure is etiologically associated with the occurrence of AD.
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The longitudinal epiphyseal bracket is a rare ossification defect of bones of the hands and feet and results in an abnormal epiphysis that is C-shaped, longitudinally oriented, and vertically extends into the diaphysis. The longitudinal epiphyseal bracket may exist as an isolated deformity, but is commonly associated with digital deformities such as polydactyly, duplicated digits, congenital hallux varus, and clinodactyly. Five case histories of children with the longitudinal epiphyseal bracket in different bones of the foot are described with three distinct clinical presentations. The development of the longitudinal epiphyseal bracket and implications for treatment are considered.
The introduction of stochastic methods in pedigree analysis has enabled geneticists to tackle computations intractable by standard deterministic methods. Until now these stochastic techniques have worked by running a Markov chain on the set of genetic descent states of a pedigree. Each descent state specifies the paths of gene flow in the pedigree and the founder alleles dropped down each path. The current paper follows up on a suggestion by Elizabeth Thompson that genetic descent graphs offer a more appropriate space for executing a Markov chain. A descent graph specifies the paths of gene flow but not the particular founder alleles traveling down the paths. This paper explores algorithms for implementing Thompson's suggestion for codominant markers in the context of automatic haplotyping, estimating location scores, and computing gene-clustering statistics for robust linkage analysis. Realistic numerical examples demonstrate the feasibility of the algorithms.
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The authors present analyses of data from three independent clinical series and controls indicating an association between working in occupations with probable medium to high exposure to extremely low frequency (< 300 Hz) electromagnetic fields and sporadic Alzheimer's disease. Case-control analyses were carried out using data from patients examined at the following locations: the Department of Neurology, University of Helsinki, Helsinki, Finland, 1982-1985; the Koskela Hospital in Helsinki, 1977-1978; and the University of Southern California site of the Alzheimer's Disease Research Center of Los Angeles and Orange Counties, 1984-1993. The predominant occupations among medium (2-10 mG or > 10 mG intermittently) to high (> 10 mG or > 100 mG intermittently) exposed cases were seamstress, dressmaker, and tailor. The results appear to be independent of education, and the sex-combined odds ratios for the three series are quite homogeneous: 2.9, 3.1, and 3.0. The odds ratio for the three series analyzed together is 3.0 (p < 0.001), with a 95% confidence interval of 1.6-5.4. The odds ratio for women is 3.8 (p < 0.001), with a 95% confidence interval of 1.7-8.6. The most obvious, possibly etiologically relevant exposure is that of electromagnetic fields, which may have biologic plausibility because they may adversely influence calcium homeostasis and/or inappropriately activate immune system cells such as microglial cells, initiating events that result in neuronal degeneration.
Case ascertainment for an epidemiologic study of Creutzfeldt-Jakob disease (CJD) can be difficult. This report investigates the efficiency of various sources of case ascertainment for CJD. Cases were identified utilizing neuropathologists, hospitals and death certificates from 11 targeted states. For the period of 1986-1988, 247 death certificates indicating a diagnosis of CJD were obtained. Only 26 potential cases were identified without death certificates. The proportion of neuropathologically confirmed cases identified by death certificates only, i.e., which were not identified through any other source, was 42%. Furthermore, 80% of all the neuropathologically confirmed cases were ascertained utilizing death certificates as a source. Of the remaining 20%, 7% were ascertained through neuropathologists only, 10% through hospitals only, 1.5% through a combination of hospitals and neuropathologists, and 1.5% through another source. The false-positive rate for death certificates with neuropathology (which may have been performed after the death certificate was filled out) was estimated to be 8.3%. The results indicate that death certificates were by far the most efficient source for initial ascertainment of potential CJD cases to be followed by verification of diagnosis.
BACKGROUND AND PURPOSE: We studied prognosis for survival after an initial stroke in 662 patients who survived at least 30 days after onset while taking into account age, sex, the number of neurological deficits from the initial stroke, stroke type, and five selected medical conditions: hypertension, myocardial infarction, cardiac arrhythmia, diabetes mellitus, and history of transient ischemic attacks. METHODS: All patients were enrolled between July 1, 1987, and August 1, 1989, and were followed regularly at about 6-month intervals until death or the end of the study (mean of 24 months). RESULTS: At 6 months, 90.8% of the 30-day stroke survivors were still alive. At 1, 2, 3, and 4 years, the cumulative survival rates were 86.9%, 78.7%, 73.2%, and 72.0%, respectively. Older age and the number of neurological deficits at onset of initial stroke increased risk of death. Compared with patients of the same age, sex, number of neurological deficits, and comorbidities, increased risk of death is present among those with myocardial infarction, cardiac arrhythmia, and diabetes mellitus. Hazard ratios were 1.7 (P = .006), 1.5 (P = .023), and 1.4 (P = .059), respectively. Hypertension and transient ischemic attacks were not significantly associated with increased mortality. CONCLUSIONS: This study clarifies prognosis for survival after an initial stroke by taking into account other confounding variables that could also contribute to risk of death.
No association between Alzheimer's disease (AD) and apolipoprotein E type epsilon 4 (ApoE epsilon 4) phenotype was found among centenarians in Finland (N = 179). The data are based on ascertainment of all centenarians in Finland in 1991. All examinations were conducted during 1991. The diagnoses of dementia and AD were based on clinical grounds, conforming to DSM-III-R and NINCDS-ADRDA criteria. The percentage of ApoE epsilon 4 alleles among the centenarians was 8.7% (31 of 358 alleles). This is significantly lower than percentages found in younger Finnish populations. Thirty (16.8%) of the 179 centenarians were epsilon 4 allele carriers. One hundred fifty-one (84.4%) of the centenarians were women. Twenty-eight (18.5%) of the women had at least one epsilon 4 allele, as did two (7.1%) of the men. The prevalence of clinically diagnosed AD was 26.8%; 44% of the subjects were cognitively normal, 23% had signs of cognitive decline or at most mild dementia (with no differential diagnosis), and 6% had a dementia clinically diagnosed as being due to some cause other than AD. For AD cases versus cognitively normal subjects, the odds ratio associated with being a carrier of the epsilon 4 allele was 1.34 (p = 0.64; 95% CI = [0.5, 3.3]). Among women, the odds ratio was 0.99 (p = 1.0; 95% CI = [0.4, 2.6]). There were fewer, but not significantly so, epsilon 4 carriers among subjects with cognitive decline or at most mild dementia (12.2%) than there were among the cognitively normal subjects (16.5%). The AD patients had no evidence of difficulty standing on a flat stationary surface unless the surface suddenly moved.(ABSTRACT TRUNCATED AT 250 WORDS)
Synthetic heptapeptide growth hormone-releasing peptide-1 (GHRP-1) potently stimulates GH release in many species, including humans. We investigated the direct in vitro effect of this peptide, compared to growth hormone-releasing hormone (GHRH), on cultured human thyroid follicles. The results indicate that whereas GHRP-1 (6-600 micrograms/l) or GHRH (6-600 micrograms/l) alone had no effect on basal triiodothyronine (T3) secretion or cAMP formation, the heptapeptide (6-600 micrograms/l), but not GHRH (6-1200 micrograms/l), dose-dependently inhibited thyrotropin (TSH)-stimulated T3 secretion and cAMP formation. Moreover, GHRP-1 also dose-dependently inhibited forskolin-stimulated T3 secretion. It would seem, therefore, that the GHRP-1-induced inhibitory effect on thyroid function is located downstream of cAMP formation, without necessarily excluding an additional inhibitory action at a pre-cAMP site. These results additionally demonstrate differences in the mode of action of GHRP-1 and GHRH.
Two cases of tuberculosis of the foot are described. The diagnosis for each was delayed and unexpected. The clinical features of osteoarticular tuberculosis are reviewed along with practical guidelines for diagnosis.
A case history of an 8-year-old girl with cerebral gigantism (Sotos' syndrome) has been presented. Throughout her life, this child has demonstrated all of the common features of Sotos' syndrome including large size at birth, excessive growth during childhood, dysmorphic craniofacial features, delay in motor and speech development, generalized clumsiness, and awkward gait. Family history was contributory with delays in early language development and the possibility that the child's father had Sotos' syndrome. When evaluating a pediatric patient for pes planus, delayed walking, and gait problems, the practitioner should consider the entire clinical profile and unusual etiologies.
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To evaluate the hypothesis that socioeconomic status would exert greater influence on patients' care-seeking behavior than racial/ethnic group status, we undertook a sequential study of African-American, Latino, and white patients hospitalized for acute chest pain from August 1988 through July 1990 at two sites. The study took place in an urban public medical center and an urban private health maintenance organization medical center, which provide care to mixed racial/ethnic groups of lower and middle socioeconomic status, respectively, in Los Angeles. Three concurrent case series of African-American, Latino, and white patients hospitalized for acute chest pain were recruited. The racial/ethnic distribution of the total group was African Americans, 448; Latinos, 487; and whites, 499. The main outcome measure was the length of time patients spent in deciding to seek emergency medical care for acute chest pain and the associated perceptions, behaviors, and motivations involved in deciding to seek care. For the total group, public hospital site and lack of health insurance were the strongest significant predictors of a longer decision phase, whereas differential symptom perceptions, consultation with medical professionals, and use of paramedic transport were significant predictors of shorter duration. Multiple regression results were similar in separate analyses demonstrated significant differences in patients' perceptions of symptom intensity and incapacitation within racial/ethnic groups related to socioeconomic status, as well as in specific behavior and motivation in seeking care. The study concluded that socioeconomic status as determined by hospital site exerted a stronger influence on patients' care-seeking behavior for acute chest pain than racial/ethnic status. Specific care-seeking behaviors of minority and lower-socioeconomic-status patients in the use of medications and paramedics in the face of acute symptoms should be targeted in future educational programs.