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Biomedical subjects

M Sigman

Publications and source records attributed to M Sigman.

At least 73 records · Page 4Linked to original sources
PubMed1992

Medical illness in school-age Kenyans in relation to nutrition, cognition, and playground behaviors.

Because medical illness is associated with malnutrition, it might contribute to the poor outcomes seen in malnourished children. This study explored relations between frequency of mild illness and development in 133 mild-to-moderately malnourished school-age Kenyan children. Morbidity information was collected for one year. Concurrent assessments of cognitive status and playground behaviors were obtained. Nutritional and environmental variables were also assessed. Girls with more reported days of mild illness performed less well on developmental measures than did their healthier female peers. They were less cognitively advanced, and, on the playground, girls with more mild illness were less active, happy, and social. Furthermore, relations between frequency of mild illness and playground behaviors (but not cognitive score) in the girls remained statistically significant when other variables, such as socioeconomic status, parental literacy, food intake, and anthropometry, were considered. For the boys, frequency of mild illness was not related to cognition or play behaviors.

Affective Symptoms↗
PubMed1991

Prediction of cognitive competence in Kenyan children from Toddler nutrition, family characteristics and abilities.

This study explored the extent to which cognitive competence in 5-yr old Kenyan children was associated with earlier nutritional factors, family conditions and toddler characteristics. Food intake during the 18th-30th mths and physical stature at 30 mths were associated with cognitive skills at 5 yrs. Measures of family background, abilities of the child as a toddler and current schooling were also associated with cognitive abilities at 5 yrs. These variables influenced development independently, so that later cognitive competence was best predicted by a combination of earlier nutritional, family and toddler characteristics.

Aptitude↗
PubMed1991

Assisted reproductive technics for the treatment of male factor infertility.

Several treatment choices remain for the couple with male factor infertility due to idiopathic male infertility or in couples in which specific therapy has failed. Empiric medical therapy continues as a viable option; however, the physician and patient must understand that the success rates with any of the pharmacological therapies remain suboptimal. In addition, this therapy should only be used for patients with idiopathic male infertility. It is not indicated for other classes of infertile males. Another option is that of IVF and related technologies. These technics continue to improve and we can expect more specific technics to be developed to optimize fertilization and pregnancy rates in those couples with male factor infertility. At the present time, the pregnancy rates achieved with this technology in male factor couples are less than those in non-male factor patients. In addition, all of these technics entail considerable expense, often not covered by insurance. The third alternative for the patient with idiopathic male infertility is that of therapeutic insemination with the husband's sperm. Recent studies combining ovarian hyperstimulation with IUI suggest a clear advantage of this technic over other insemination approaches. As this treatment is significantly less expensive and time-consuming than the prior therapies, it should be considered when choosing therapy. Additional choices the couple with male factor infertility should consider are adoption and therapeutic donor insemination. It is only after careful consideration of all the available options that an appropriate decision can be made. This will vary, depending on the particular clinical characteristics of the couple as well as their social and financial situation.

Humans↗
PubMed1991

Relationships between morbidity and development in mildly to moderately malnourished Kenyan toddlers.

This study explored the extent to which morbidity in 110 mildly to moderately malnourished Kenyan toddlers was associated with developmental outcomes. Morbidity information was collected from the 18th to 30th months. Concurrent assessments of vocalization, play, and performance on the Bayley scales were obtained. At 5 years, a follow-up battery of cognitive tests was administered. Female toddlers who suffered more illness generally performed less well on developmental measures than their healthier female peers. These children vocalized and played less and performed less well on the Bayley Mental scales at 30 months and on the cognitive battery at 5 years. For the boys, development was largely independent of morbidity. Morbidity was related to patterns of care giving for both boys and girls, but it was not associated with socioeconomic status or food intake. However, girls who were ill more often were shorter and lighter. Relations between morbidity and development in the girls remained statistically significant when other variables, which were also related to development (such as care giving, socioeconomic status, parental IQ and literacy, food intake, and anthropometry) were considered. This suggests that morbidity, in these female toddlers, had an effect on development above and beyond other variables typically associated with malnutrition.

Child Development↗
PubMed1990

Affective sharing in the context of joint attention interactions of normal, autistic, and mentally retarded children.

Disturbances in the development of joint attention behaviors and the ability to share affect with others are two important components of the social deficits of young autistic children. We examined the association of shared positive affect during two different communicative contexts, joint attention and requesting. The pattern for the normal children was one of frequent positive affect displayed toward the adult during joint attention situations. Compared to the normal children, the autistic children failed to display high levels of positive affect during joint attention whereas the mentally retarded children displayed high levels of positive affect during requesting as well as joint attention situations. These results lend support to the hypothesis that the joint attention deficits in autistic children also are associated with a disturbance in affective sharing.

Affect↗
PubMed1990

A longitudinal study of joint attention and language development in autistic children.

This study was designed to examine the degree to which individual differences in gestural joint attention skills predicted language development among autistic children. A group of 15 autistic children (mean CA = 45 months) were matched with one group of mentally retarded (MR) children on mental age and another group of MR children on language age. These groups were administered the Early Social-Communication Scales. The latter provided measures of gestural requesting, joint attention, and social behaviors. The results indicated that, even when controlling for language level, mental age, or IQ, autistic children displayed deficits in gestural joint attention skills on two testing sessions that were 13 months apart. Furthermore, the measure of gestural nonverbal joint attention was a significant predictor of language development in the autistic sample. Other variables, including initial language level and IQ were not significant predictors of language development in this sample.

Attention↗
PubMed1990

Relationship of milk iron and the changing concentration of mammary tissue transferrin receptors during the course of lactation.

The concentration of iron in all mammalian milks falls during lactation while the infant's iron requirement increases. Little is known, however, about the entry of iron into milk. Recently, transferrin receptors have been identified on lactating rat mammary plasma membranes, which may regulate iron entry into mammary tissue, potentiating its availability for subsequent transport into milk. This study was conducted to determine what relationship exists between the declining concentration of milk iron and the transferrin receptor concentration during various stages of lactation. Minimal transferrin receptors were detected in nulliparous rats. Total mammary transferrin receptor content increased during early and mid-lactation while milk iron concentration decreased. The continued appearance of high levels of transferrin receptors throughout lactation, without a concomitant increase in milk iron concentration, suggests a need for iron for functions other than cellular growth or secretion into milk to meet infant needs.

Journal Article↗
PubMed1990

Characterization of transferrin receptors on plasma membranes of lactating rat mammary tissue.

Little is known about the transport of iron into the mammary secretory cell and the process of milk iron secretion. The concentration of iron in milk is remarkably unaffected by maternal iron status, suggesting that the uptake of iron into the mammary gland is regulated. It is known that iron enters other cells via transferrin receptor-mediated endocytosis. This study was designed to isolate and characterize the mammary gland transferrin receptor in lactating rat mammary tissue using immunochemical techniques. The existence of functional mammary gland transferrin receptors in lactating rodents was demonstrated using radiolabel-binding techniques. Isolation of mammary transferrin receptors by affinity chromatography was confirmed using immunoelectrophoresis and slot blot analysis. The intact transferrin receptor was found to have a molecular weight of 176 kd as determined by Western blotting followed by scanning densitometry. Reduction of the receptor with beta-mercaptoethanol gave a molecular weight of 98 kd. An additional immunoreactive band of 135 kd was observed. The presence of transferrin receptors in normal lactating rat mammary tissue is likely to explain iron transport into mammary tissue for both cellular metabolism and milk iron secretion.

Journal Article↗
PubMed1990

Response of rat mammary gland transferrin receptors to maternal dietary iron during pregnancy and lactation.

Mammalian milk iron (MFe) concentration decreases during lactation. In human attempts to increase MFe through supplementing the mother with iron during lactation have failed and no correlation between maternal iron status or intake and MFe has been determined, suggesting a regulatory mechanism. In contrast MFe in lactating rats can be affected by very high or low amounts of ingested iron. We previously described a transferrin receptor (TfR) mechanism that controls iron entry into rat mammary tissue. In this study lactating rats were used to determine effects of varying dietary iron during gestation and lactation on mammary TfR and MFe. Dams fed low-iron diets had a small increase in TfR, lower hematological indices (p less than 0.005), and lower MFe (p less than 0.005) than did controls or dams fed high iron. Dams fed the high-iron diet had a significant increase in TfR without a concomitant increase in MFe. There was no correlation between MFe and TfR. These findings suggest that control of MFe lies after iron entry into mammary tissue.

Animals↗
PubMed1990

Dynamics of a human seminal vesicle specific protein.

The present paper is concerned with the temporal alterations and tissue localization of a seminal antigen secreted by the human seminal vesicle. This antigen is recognized by antibody MHS-5, which is one of a set produced in mice by immunization with human sperm. The respective clone produced an antibody of the IgG1 subtype, which reacted with seminal fluid from over 400 normal donors and 21 semen samples from vasectomized men. Incubation of seminal vesicle secretion with either prostatic fluid or prostate specific antigen (PSA) resulted in degradation on the antigen. The experiments showed that MHS-5 antigen is a substrate for the serine protease PSA: Immunohistochemical studies suggested that MHS-5 is a "sperm-coating" antigen and is exclusively synthesized and secreted by the seminal vesicle.

Antigens↗
PubMed1990

Affect and attention in children with Down syndrome.

The association of the affective responsiveness and attention regulation with communication and language skills of children with Down syndrome was examined. Results both replicate and extend previous research on the attentional and affective characteristics of children with Down syndrome. These children tended to look more often to the face of the social partner but less often to nonfocal toys. They also tended to shift affect expressions more frequently but did not differ from MA-matched nonretarded children in overall durations of affect. The association of these variables with communication and language indicated that the more positive affect displayed toward people and the shorter the average looks to the partner's face, the higher the verbal language skills of young children with Down syndrome.

Affect↗
PubMed1990

Referral barriers--near failure to thrive of a group.

This paper describes the purpose, goals and painful beginnings of a free group service to chronic, low functioning, psychiatric outpatients in a hospital system. The 'Thursday Group' was first made available in 1985 for patients who are depressed, psychotic or otherwise severely emotionally disturbed. It has few restrictive criteria, yet it nearly 'failed to thrive' and almost perished due to lack of referrals. This paper focuses on some possible reasons for the referral barriers. They include the degree of visibility of the therapist in the system, habit and the status of group treatment in the minds of staff, the dynamics of these patients and patient-staff relationships, the staff's own dynamic and their position within the system, and finally the understanding of the limits and capacities of a group. The therapeutic value of the group and its more hopeful current place in the system is described.

Chronic Disease↗
PubMed1989

Relationship between nutrition and development in Kenyan toddlers.

The relationship between mild to moderate malnutrition, as measured by food intake and anthropometric status, and developmental outcome was explored in 110 Kenyan toddlers. Developmental outcome was assessed at 30 months of age by the Bayley Mental and Motor scales and by evaluation of play behaviors. Verbalization and play during months 15 to 30 were also evaluated. Family background and home rearing conditions were assessed, and these variables were separated from the correlations between nutrition and outcome by partial correlation methods. Food intake was related to anthropometric status, play behaviors, and total amount of verbalization and play even when the potentially confounding effects of certain family background and home rearing variables were covaried. Food intake was not related to Bayley Mental and Motor scores, but measures of length and weight were, even when family background and home rearing variables were held constant. Mild to moderate malnutrition does appear to affect the child's development adversely even when other environmental characteristics, which also relate to development, are considered.

Anthropometry↗
PubMed1989

Social attachments in autistic children.

Social responses of young autistic children to separation from and reunion with their caregivers did not differ from the social responses to similar situations of young mentally retarded nonautistic children. Most autistic children directed more social behaviors to their caregivers than to strangers and increased their preferential behavior after separation. Individual differences in social responses were not associated with the level of representational skills shown by the autistic children.

Anxiety, Separation↗
PubMed1989

Psychometric scatter in retarded, autistic preschoolers as measured by the Cattell.

To determine whether psychometric scatter is characteristic of the developmental profile of young autistic children, the performance of 38 autistic children, as measured by the Cattell, was compared with the performance of MA matched samples of normal, Down's Syndrome and non-Down's Syndrome children with mental retardation. Results indicated significantly more psychometric scatter in the autistic group than in the other groups. Similarly, 66% of the autistic children vs 13, 26 and 32% of the normal, Down's and non-Down's samples, respectively, had significant scatter. Further analyses revealed that autistic children showed consistent relative strength in non-language and weakness in language.

Autistic Disorder↗
PubMed1989

Facial expressions of affect in autistic, mentally retarded and normal children.

This study examined the facial affect expressions of autistic, mentally retarded and normal children. Affect was coded using the Maximally Discriminative Movement Coding System. Results indicated that the autistic children were more flat/neutral in their affect expression than the mentally retarded children. Moreover, they displayed a variety of ambiguous expressions not displayed by any of the other children. This unique pattern may be related to the difficulties that autistic children have in sharing affect, and to the difficulties that others experience in reading their affective signals.

Affect↗
PubMed1989

Cognitive abilities of Kenyan children in relation to nutrition, family characteristics, and education.

The purpose of this study was to determine whether nutritional factors, family characteristics, and the duration of schooling were associated with cognitive and attentional capacities in children growing up in rural Kenya. Food intake was measured by direct observation and weighment twice monthly over the course of a year. Families were characterized in terms of socioeconomic status and the literacy of the parents. Children who were better nourished had higher composite scores on a test of verbal comprehension and the Raven's matrices. Better-nourished females were more attentive during classroom observations than malnourished female schoolchildren. Family characteristics and duration of school participation were associated with cognitive abilities for both boys and girls. For the children considered as a group, cognitive scores were best predicted by a combination of factors including duration of schooling, food intake, physical stature, and SES.

Aptitude↗