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Biomedical subjects

M Grossman

Publications and source records attributed to M Grossman.

302 records · Page 17Linked to original sources

Attention and sentence processing deficits in Parkinson's disease: the role of anterior cingulate cortex.

Parkinson's disease (PD) is a complex neurodegenerative condition involving a motor disorder that is related to reduced dopaminergic input to the striatum. Intellectual deficits are also seen in PD, but the pathophysiology of these difficulties is poorly understood. Regional cerebral blood flow (rCBF) was studied in neurologically intact subjects during the performance of attention-demanding, sentence processing tasks using positron emission tomography (PET). The results demonstrated significantly increased rCBF in a distributed set of cerebral regions during the detection of an adjective or a particular agent in a sentence, including anterior cingulate cortex, left inferior and middle frontal cortex, left inferior temporo-occipital cortex, posterolateral temporal cortex, left caudate, and left thalamus. We identified defects in this cerebral network by studying PD patients with two PET techniques. Resting PET studies revealed a significant correlation between regional cerebral glucose metabolism in anterior cingulate cortex and deficits in attending to subtle grammatical aspects of sentences. Studies of PD patients with the PET activation technique revealed little change in anterior cingulate and left frontal CBF during performance of the adjective detection or agent detection tasks. These data suggest that a defect in anterior cingulate cortex contributes to the cognitive impairments observed in PD.

Aged↗

Teaching Mendelian inheritance with a herediscope.

The herediscope is a useful teaching aid. Unlike some of the more sophisticated new computer teaching aids it clearly demonstrates Mendelian inheritance and sampling variation. The herediscope is easy to construct and costs little. Students can perform numbers of trials, and quickly demonstrate to themselves the variability associated with Mendelian inheritance for both single and multiple qualitative traits, and multigene quantitative traits. Instructors should consider the use of the herediscope as a possible teaching aid when teaching Mendelian inheritance.

Genetics↗

Logistic growth curve of chickens: heritability of parameters.

Parameters of the logistic function of growth, fit to individual body weight curves of two randombred control populations of each sex of chickens from hatching to 45 weeks of age, were evaluated. Growth-rate constant and age at the infection point in the curve were estimated by the method of sample quantiles from individual weekly body weights of 225 males and 281 females of the Rhode Island Red (RIR) line, and 164 males and 239 females of the White Leghorn (WL) line. Heritability estimates, based on correlation among full-sibs, of growth rate constant were 0.18 +/- 0.32 in males and 0.29 +/- 0.29 in females of the RIR line, and 0.41 +/- 0.40 in males and 0.46 +/- 0.32 in females of the WL line. Estimates of heritability of age at the inflection point were 0.36 +/- 0.44 in males and 0.42 +/- 0.32 in females of the RIR line, and 0.46 +/- 0.41 in males and 0.50 +/- 0.28 in females of the WL line. Observed variation for each trait probably does not provide evidence for heritable differences. No genetic correlations were evident among growth-rate constant, age at the point of inflection, and initial or maximum weight. According to these results, it does not appear that selection for growth-rate constant or age at the point of inflection will change the shape of the growth curve of these populations genetically. Moreover, correlated genetic change in initial or maximum weight would not be expected.

Aging↗

Inbreeding, coancestry, and covariance between relatives for X-chromosomal loci.

Knowledge about the relationships between relatives for X-chromosomal loci is necessary to compute genetic variances and covariances for the genetic evaluation of individuals for economically important traits in livestock and poultry. Using a unified approach, we derived explicitly the coefficient of inbreeding for individuals and the coefficient of coancestry between collateral and lineal relatives of the same or different sex, assuming that the male is heterogametic and the female is homogametic. Collateral relatives include full sibs, paternal and maternal half-sibs, paternal and maternal single first cousins, and double first cousins. Lineal relatives include parent-offspring, paternal and maternal grandparent-grandoffspring, and aunt- or uncle-niece or -nephew. We also defined additive and dominance relationships to compute genetic covariance between relatives, assuming random mating equilibrium, and clarified misinterpretations and corrected errors in the literature. Our results are also applicable to organisms that have few autosomal loci, such as Drosophila, in which X-chromosomal loci can account for a large amount of genetic variance, and to haplodiploid organisms, such as the honeybee, in which the entire genome is equivalent to being X-chromosomal.

Animals↗

Management of the febrile patient.

Fever is one of the most common complaints presented to the child's pediatrician or health provider. Some 20% of children seen in the office or clinic are there because of fever. The first decision the physician faces is over the phone: who should be seen immediately and who can be managed over the phone. The purpose of the consultation and the visit is to separate those with inconsequential febrile illness from those who have serious illnesses, bacterial illnesses in particular, since these could be life-threatening and are amenable to antimicrobial therapy. Many studies performed over the past 10 years are essentially in agreement that high fever in children younger than 2 years includes a subset of about 6 to 10% with bacteremia caused principally by S. pneumoniae and H. influenzae. The higher the fever (particularly over 40%) the higher the risk of bacteremia. Examination of the young child elicits two sets of findings. These are traditional physical clues to a specific diagnosis, such as tachypnea, crepitant rales, stiff neck, swollen joints and others. Additionally there are general observational clues dealing with how sick the child really is. The physician then needs to decide which of several possible laboratory tests need to be done in order to further refine a subset of children at high risk. The white count (less than 5000 or greater than 15,000), the band count (greater than 1500) and the sedimentation rate (greater than 30 mm/hour) have proved useful in various studies, as has examination of the urine.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Infective Agents↗

Current cardiology problems in sports medicine.

The cardiologist involved in the evaluation of the competitive athlete requires knowledge of the normal variations seen on clinical examination and laboratory studies. There is limited information in the literature, currently, that provides guidelines for decision making in the face of cardiac abnormalities. This paper outlines our experience with athletes and cardiac disease. Recommendations are given as guidelines for specific activity allowances.

Adolescent↗

MR lesion load and cognitive function in patients with relapsing-remitting multiple sclerosis.

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is a demyelinating disease most often associated with progressive physical impairment; however, its effects are noted to extend beyond physical disability. Our purpose was to determine the relationship between T2 lesion volume and neurocognitive and physical disability in relapsing-remitting multiple sclerosis. METHODS: We studied a cohort of 19 patients with relapsing-remitting MS. Of this group, there were 15 women and four men from varying socioeconomic backgrounds. This volunteer sample was selected from a larger group of 53 patients with MS in our longitudinal MS study because they had been untreated with any beta-interferon medications, had been followed for at least 12 months, and had a clinical status of relapsing-remitting MS. RESULTS: Of 12 neurocognitive parameters tested, two correlated significantly with lesion loads. The correlation of the Symbol-Digit Modalities test, which analyzes information-processing speed, was significant (P = .0204). The correlation of the fifth trial of the Rey Auditory Verbal Learning test, which tests verbal long-term memory, was also significant (P = .0348). None of the other 10 neurocognitive examinations, however, showed a significant correlation with total lesion volume (Paced Auditory Serial Addition test-1.6, P = .7381; Paced Auditory Serial Addition test-2.0, P = .4180; Controlled Oral Word Association test, P = .8906; Category Fluency test, P = .4423; Bells test, P = .9097; Rey Auditory Verbal Learning test-delay, P = .9843, Rey Auditory Verbal Learning test-recognition, P = .7467; Word Span test, P = .4939; Road Map test, P = 0.4939). The lesion load also did not correlate with the physical disability scales as rated according to the Expanded Disability Status Scale (P = .68) or Ambulation Index (P = .95). CONCLUSION: Our results indicate that T2 lesion volume does not seem to be a robust surrogate marker of neuropsychological impairment in patients with MS. We think that global measurements of parameters that are more specific to the disease process may offer more precise correlation with cognitive dysfunction and other disability parameters.

Adult↗

Adverse dermatologic effects of cardiovascular drug therapy.

Cardiovascular disease is common, affecting an increasing number of persons as the population ages. To combat this growing health problem, physicians use a multitude of medications in the treatment of their patients. Although pharmacologic therapy greatly enhances quality of life for a majority of patients, there is always the potential for an unfavorable reaction. For example, cardiovascular drugs can induce a vast array of adverse dermatologic responses. This article reviews the various cutaneous reaction patterns that can occur as a result of treatment with specific cardiovascular agents.

Cardiovascular Agents↗

Logistic growth curve of chickens: a comparison of techniques to estimate parameters.

Parameters of a mathematical function of growth, fit to the body weight curve of two randombred control populations of each sex of chickens from hatching through 45 weeks of age, were estimated. The logistic function was chosen from among growth formulae that express rate of gain as a function of weight at a given time and gain to be made. Two logistic parameters, growth-rate constant and age at the point of inflection, were estimated by the methods of sample quantiles and nonlinear regression from weekly mean body weights of 225 males and 281 females of the Rhode Island Red (RIR) line, and 164 males and 239 females of the White Leghorn (WL) line. Males had a larger growth-rate constant than females of the same line. The RIR line had a larger rate constant than the WL line, for each sex. Age at the point of inflection was similar for males and females in the RIR line, but smaller for males than females in the WL line. Sample quantiles yielded larger, less precise estimates of the growth-rate constant than nonlinear regression. Estimates of age at the point of inflection were usually smaller using sample quantiles.

Aging↗

Cigarette taxes. The straw to break the camel's back.

Teenage cigarette smoking is sensitive to the price of cigarettes. The most recent research suggests that a 10% increase in price would reduce the number of teenagers who smoke by 7%. If the proposed 43-cent hike in the Federal excise tax rate on cigarettes contained in the Hatch-Kennedy Bill were enacted, the number of teenage smokers would fall by approximately 16%. This translates into more than 2.6 million fewer smokers and more than 850,000 fewer smoking-related premature deaths in the current cohort of 0 to 17-year-olds. Adjusted for inflation, the current 24-cent-a-pack tax costs the buyer about half of the original cigarette tax of 8 cents imposed in 1951. A substantial tax hike would curb youth smoking; this strategy should move to the forefront of the antismoking campaign.

Adolescent↗