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Biomedical subjects

M Sigman

Publications and source records attributed to M Sigman.

At least 109 records · Page 6Linked to original sources
PubMed1986

Alcohol use in primiparous women older than 30 years of age: relation to infant development.

The effects of maternal alcohol use on mental development, growth, and dysmorphogenesis was studied in a sample of 1-year-old infants born to elderly primiparous mothers. Alcohol intake was measured using Jessor's AA score and a simple count of maximum number of drinks consumed in one day. Infant cognition was assessed using the Bayley Scale of Mental Development. Alcohol levels prior to, during, and following pregnancy were obtained. Alcohol intake was greatly reduced during pregnancy, returning to pregnancy levels following birth. A significant linear relationship between drinking prior to pregnancy and infant mental development was found. The average mental development score of infants whose mothers consumed less than or equal to 3, 3.3 to 29.7, or greater than or equal to 30 mL (less than or equal to 0.10, 0.11 to 0.99, or greater than or equal to 1.0 average fluid ounces) of absolute alcohol per day was 115, 108, and 95, respectively. Maximum number of drinks consumed in a day related to physical anomalies. No alcohol measure was significantly correlated with condition at birth, postnatal illness, or growth parameters of height, weight, and head circumference at 1 year. Deficits found were less pronounced than those reported in infants with fetal alcohol syndrome.

Adult↗
PubMed1985

Human antisperm monoclonal antibodies constructed postvasectomy.

Sperm and spermatogenic cell antigens, escaping the blood-testis/blood-epididymal barrier, elicit an autoimmune response in patients following vasectomy. In this study, antisperm antibody-positive sera and peripheral blood lymphocytes were obtained 6-9 mo following vasectomy. Serum antisperm antibody levels were assessed by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence. Lymphocyte-myeloma hybridomas were constructed by fusing peripheral blood lymphocytes, harvested from antisperm antibody-positive sera, with a hypoxanthine guanine-phosphoribosyltransferase (HGPRT)-negative mouse myeloma line. Immunoglobulin-secreting colonies surviving drug selection were detected by ELISA and screened for antisperm activity. Antisperm antibody-producing cultures were cloned and expanded for bulk antibody production both in culture and as ascites in athymic nude mice. Eight mouse-human fusions yielded 205 hybridomas secreting human monoclonal antibody, of which 11 demonstrated antisperm reactivity by ELISA. Two of these hybridomas are described in detail: HAS-1, which secretes human immunoglobulin M (IgM, kappa)-recognizing epitopes located on the sperm midpiece, and HAS-2 (IgM, lambda), which secretes monoclonal antibody-recognizing epitopes located on the entire sperm tail. The results indicate successful capture of human antisperm autoantibody from the postvasectomy autoimmune state using somatic cell hybridization techniques.

Animals↗
PubMed1984

Attachment behaviors in autistic children.

The social behaviors of 14 autistic children and 14 normal children of equivalent mental age were observed during a free-play situation as well as during separation from and reunion with their mothers and a stranger. As a group, the autistic children showed evidence of attachment to their mothers, directing more social behaviors and more physical contact to their caregivers than to the stranger during the reunion episodes. Within the autistic group, the children who showed an increase in attachment behaviors in response to separation and reunion demonstrated more advanced symbolic play skills than those autistic children who showed no change in attachment behaviors. One possible explanation may be that autistic children require more advanced levels of symbolic ability to form attachments to others than is necessary for the development of attachments in normal children.

Anxiety, Separation↗
PubMed1984

The relation of play and sensorimotor behavior to language in the second year.

The concurrent and predictive relations of sensorimotor behavior and play to language in the second year were assessed. 19 preterm and 20 full-term infants were tested at 13 1/2 and 22 months of age. Functional play directed toward dolls and other persons and meaningfully related sequences of functional and symbolic acts at 13 1/2 months were associated with language measured at 13 1/2 months and 9 months later. Concurrent positive relations between sensorimotor behavior and language were found only at 22 months for object-permanence skills. There were no significant positive relations between sensorimotor behaviors at 13 1/2 months and language at 22 months. The consistent relations found between play and language in this research derived from the infants' ability to translate experience into symbols that are used as a means of interacting and communicating with others. Sensorimotor behavior and language were much more loosely associated in the same age period.

Cognition↗
PubMed1983

Cognitive inhibition of human gastric acid output--studies using telemetric measurements.

In study I subjects had two sessions--one to examine the effects of reading and another to study the effects of relaxation exercises. An incomplete crossover design was used. Subjects (N = 13) decreased mean acid output by 32.2% while reading and 2.5% after relaxation exercises (N = 14). In study II, six subjects each had one session to examine the effects on acid output of a difficult maze-solving task. Mean acid output during maze-solving decreased 52.6% relative to the control period. The results of these two studies suggest that the degree of cognitive involvement is an important factor in the decrease of acid output. A modification of the Heidelberg telemetry equipment was described. It permitted a continuous measure of gastric acid output, was relatively nonaversive to subjects, and minimized the risk of cephalic or gastric phase effects of acid secretion due to the measuring technique. It is recommended as a valuable adjunct for studies designed to change gastric acidity.

Adolescent↗
PubMed1983

Moral judgment in relation to behavioral and cognitive disorders in adolescents.

The capacity for formulating moral judgments shown by 20 emotionally disturbed, cognitively delayed adolescents was related to their social behaviors as observed in a classroom situation. Adolescents reported by their teachers to be shy and submissive were less capable of reasoning about moral issues than were adolescents who were seen as more assertive and socially engaged. The level of moral judgment was not a function of intelligence or ability to understand concrete operations. The implication that social engagement is a critical determinant of moral judgment for these adolescents is discussed.

Adolescent↗
PubMed1983

Sleep behavior of preterm children at three years of age.

Caregivers of 50 preterm children completed a questionnaire relating to their child's sleep behavior at three years of age. Assessments of the children's EEGs at term and three months, medical status at birth and at four, nine and 24 months, caregiver-child interaction at one, eight and 24 months, the Bayley Scales at 25 months and the Stanford-Binet at five years of age were also obtained. Sleep disturbances were frequently noted at three years of age. However, by five years of age, the number of reported sleep-problem children was greatly reduced, and they were not the same children with sleep problems at three years. Surprisingly, children with the greatest difficulty falling asleep at night at three years were likely to have had fewer medical problems, higher scores on the Bayley scales, and more positive social interactions with their caregivers in the first two years. The relationships among early physical, psychological and social development and sleep behavior are discussed.

Age Factors↗
PubMed1983

Developmental lags in preterm infants from one to three years of age.

Assessments of play, sensorimotor, language, and general developmental skills were administered to 20 preterm and 20 full-term infants at comparable corrected and postnatal ages in 5 sessions during the second and third years of life. Clear effects of biological maturity on play and sensorimotor skills were demonstrated at 13 1/2 months, and less pervasive effects remained at 22 months. Furthermore, the preterm infants were significantly delayed in sensorimotor, personal-social, and gross motor abilities at 13 1/2 months and in language abilities at 22 months beyond that predicted by biological maturity alone. While these deficits were mostly overcome by 3 years, the preterm infants performed somewhat more poorly on visual information-processing tasks. This investigation demonstrated that the development of representational abilities as manifested in play and sensorimotor behaviors was clearly related to corrected age rather than postnatal age.

Child Development↗
PubMed1982

Neonatal risk factors in preterm infants.

This paper highlights the research literature on neonatal risk factors and explores the paradox that these factors present. Clinical and retrospective studies indicate that children who have developmental problems have had birth complications. On the other hand, birth complications do not predict developmental problems. Data from a longitudinal study of preterm infants are presented. A group of 59 preterm infants from English Speaking homes was assessed repeatedly from birth to age 5. A significant percentage of the children performed within the normal range or above, at each assessment period. Obstetrical and postnatal complications were not significantly related to developmental performance at any assessment period yet sickness was not to be dismissed as a risk factor. At age five, all of the children who performed poorly had experienced complications in the neonatal period. Responsive caregiving appeared to be an important factor in modifying and supporting cognitive development.

Child, Preschool↗
PubMed1981

Sensorimotor skills and language comprehension in autistic children.

The objectives of this study were to examine the level of sensorimotor concepts of young autistic children and to relate these concepts to language comprehension. A sample of 16 autistic children with a mean mental age of 24.8 months was administered a standardized scale of sensorimotor intelligence and of receptive language. The autistic children demonstrated surprisingly sophisticated sensorimotor skills, particularly object permanence. While their initial performance was inferior to that of normal controls matched on mental age, particularly in their use of objects in combination, the difference between groups diminished on the second test administration. On the receptive language measure, the autistic children were less able to identify words correctly. The sensorimotor behavior of autistic children who demonstrated language comprehension did not differ from those who showed no language comprehension, except that the former group tended to use an object as an instrument somewhat more frequently. The fact that the autistic children were so impaired in language even with fairly good sensorimotor skills suggests that these skills, particularly object permanence, play a minor role in their language acquisition.

Age Factors↗
PubMed1979

Superoxide production induced in rabbit polymorphonuclear leukocytes by synthetic chemotactic peptides and A23187.

SYNTHETIC FORMYL METHIONYL CHEMOTACTIC PEPTIDES INDUCE THE VARIOUS MANIFESTATIONS OFTHE RESPIRATORY BURST: increased 0(2) consumption, activation of the hexose mono-phosphate shunt, and increased production of superoxide (0(2) (-)) and H(2)0(2). They do soalone but to a much greater extent when in the presence of cytochalasin B. Superoxidegeneration by the chemotactic peptides in the presence of cytochalasin B shows thesame relationship of structure to activity as does the stimulation of chemokinesis andchemotaxis, granule enzyme secretion, and neutrophil aggregation by these sameagents. Carbobenzoxy-phenylalanyl-methionine, CBZ-Phe-Met, competitively inhibitsthe induced stimulation of locomotion, granule enzyme secretion, and neutrophilaggregation caused by the synthetic peptides. It also is a competitive inhibitor of O(2) (-) generation by the same peptides. The structure-activity and the competitive inhibitor studies lead to the conclusion that in polymorphonuclear leukocytes the chemotactic peptides induce superoxide formation and presumably the other manifestations of the respiratory burst by interacting with the same membrane receptor responsible for the stimulation of chemokinesis, chemotaxis, granule enzyme secretion, and neutrophil aggregation. The effectiveness of formyl-methionyl-leucyl-phenylalanine, F-Met-Leu-Phe, in generating 0(2) (-) is greatly reduced but not abolished by removing calcium from the external medium. The calcium ionophore A23187 induces 0(2) (-) generation that requires external calcium and is greatly enhanced by cytochalasin B. From these findings we hypothesize that the proximate cause of the induction of 0(2) (-) formation and other manifestations of the respiratory burst by the chemotactic peptides is the influx into the neutrophil of Ca(2+) and/or possibly Na(+) previously shown to be induced by the peptides.

Animals↗
PubMed1978

Organophosphorus inhibition of lysosomal enzyme secretion from polymorphonuclear leucocytes. Evidence of a lack of a requirement for esterase activation.

Previously, di-isopropylphosphorofloridate (DFP) was shown to inhibit the release of lysosomal enzymes induced by chemotactic factors. It was suggested that the inhibition was due to the phosphorylation of a cell bound serine esterase activated by the chemotactic factor. However, as shown here, di-isopropyl methyl phosphate, a nonphosphorylating analogue of DFP, inhibits just as well as DFP, the release of lysozyme and beta glucuronidase from rabbit polymorphonuclear leucocytes induced by chemotactic factor in the presence of cytochalasin B. Similarly, the poorly phosphorylating phenyl ethyl pentylphosphonate and phenyl ethyl phenylpropylphosphonate inhibit enzyme release, induced under the same conditions, as well as or better than the corresponding good phosphorylators, p-nitropheny ethyl pentylphosphonate and p-nitrophenyl ethyl phenylpropylphosphonate. Phenyl ethyl pentylphosphonate inhibits at least as well or probably better than p-nitrophenyl ethyl pentyl phosphonate, the chemotactic factor induced relase of lysozyme from polymorphonuclear leucocytes spread on Millipore filters in the absence of cytochalasin B. We conclude that, under the circumstances tested, there is no evidence that the release of lysosomal enzymes from rabbit peritoneal polymorphonuclear leucocytes induced by chemotactic factor involves the activation of an esterase.

Animals↗