published_or_final_version / Community Medicine / Doctoral / Doctor of Philosophy

The fecal flora of healthy bottle or breast-fed infants was examined for the presence of Bifidobacterium. Identification was based on the presence of fructose-6-phosphate phosphoketolase, which is found only in these bacteria. No bifidobacteria were recovered from bottle-fed infants. However, bifidobacteria were readily isolated from 15 day to 3 month old breast-fed infants. Further characterization revealed B. breve and B. longum were the dominant species in feces of breast-fed infants, but atypical strains also were found. A whey-based medium (7% sweet whey, 0.05% cysteine and 0.3% yeast extract, WCY-0.3) was developed to grow Bifidobacterium species without use of anaerobic incubation conditions. Freshly pasteurized WCY-0.3 was inoculated with 0.2% (10⁶ to 10⁷ CFU/ml) of the following active cultures of bifidobacteria: B. bifidum 15696, B. breve 15700, B. longum 15707, B. breve 15698, B. longum L10, B. longum L12, and B. longum 3j. Following incubation for 12 hours, most strains reached cell densities of 10⁹ to 5 x 10⁹ CFU/ml, except B. bifidum 15696 and B. longum 3j. Addition of Oxyrase to the WCY (WC with any level of yeast extract) at 0.03 unit/ml (WCYO) reduced the lag phase of all strains, allowing maximum populations to be reached more quickly. A higher population density (2 to 7 times) could be achieved in the WCOY-0.3 medium with strains 15696, 15700, 15707, and L10 by incorporating 1.9% sodium glycerophosphate or trimagnesium phosphate with incubation for 12 hours at 37°C. Also, viability of these strains was retained throughout a 24-hour incubation period, in contrast to rapid death of cells grown without the neutralizing agents. Inoculation of WCY-0.3 or WCOY-0.3 medium with frozen concentrates (10⁷ to 10⁸ CFU/ml) of bifidobacteria allowed equal growth of all species, except B. bifidum 15696, which grew much better in WCOY-0.3 than in WCY- 0.3. Survival stability of whey-based medium-grown bifidobacteria when resuspended in pasteurized skim milk and refrigerated at 4°C was strain dependent and enhanced by the presence of 0.05% cysteine; generally ATCC strains were more stable than strains freshly isolated from baby feces. In this regard, B. breve 15700, B. longum 15707, and B. breve 15698 did not lose viability in 11% skim milk with 0.05% cysteine within 10 days of storage. Stability of whey-based medium-grown bifidobacteria in WCY with 15% glycerol during six months storage at -40°C was strain dependent. Bifidobacterium bifidum 15696, B. breve 15700, B. longum 15707, B. breve 15698, and B. longum L12 did not lose viability; however B. bifidum L6 lost about 50% viability, while B. longum L10, B. breve T10, and B. breve T2 lost about one log population density. The plasmid profiles of 35 strains of bifidobacteria from human sources were examined. Only one strain, B. breve 15698, harbored a 5.8Kb plasmid. A curing process using UV-light treatment to remove the plasmid was carried out but characterictics of the cured strain were identical to those of the parent strain, indicating the plasmid is cryptic. / Graduation date: 1991

No description available.

Despite concern that preterm infants receive inappropriate tactile and auditory stimulation because of early birth, few studies have explored the development of responsiveness to tactile and auditory stimulation prior to 40 weeks' postconceptional age. The present research traced longitudinally the development of responsiveness to tactile and auditory stimulation of 14 preterm infants born at 30 or less weeks' postconceptional age. The preterm sample was divided into three groups (well, moderately ill, and sick) to assess the effects of illness. All infants were assessed three times per week from 30 to 34 weeks' postconceptional age. Body movement, eye movement, heart rate, smiles, hand-to-mouth activity, and "avoidance" signals of grimaces, cries, yawns, and tongue protrusions were assessed in response to (a) auditory stimulation in the form of talking, (b) tactile stimulation in the form of touching/stroking, and (c) the combination of talking and touching. Further, these infants were assessed weekly for the development of neurological reflexes and responsiveness to the orientation items from the Brazelton Neonatal Behavioral Assessment Scale. When a pre-stimulus period was compared to a stimulus condition, preterm infants were found to respond to talking with significantly more eye movement; to touching with significantly more body movement; and to the combination of talking and touching with more body movement. Significant effects of illness were found when smiles, hand-to-mouth activity, and "avoidance" signals were assessed. During all the stimulation conditions the well infants had significantly more smiles and hand-to-mouth activity. During talking and the combination of talking and touching the sick infants also showed significantly more "avoidance" signals. Sick infants also performed less well than the well infants on the Brazelton orientation items and on some of the neurological exam items. The findings of this study suggested that responsiveness to social stimuli, talking and touching, develops quite early, even before the time of usual birth, and is minimally affected by illness. Behaviors shown by these infants are those likely to attract the caregiver's attention, suggesting that the preterm infant is capable of behaviors which will engage the caregiver and possibly serve as the roots of social behavior. / This thesis was digitized as part of a project begun in 2014 to increase the number of Duke psychology theses available online. The digitization project was spearheaded by Ciara Healy.

Thesis (M.S.V.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1979. / Bibliography: leaves 24-25. / by David Allen Parry. / Thesis (M.S.V.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1979.

No description available.

No description available.

Infants born extremely prematurely (ie. &lt29 weeks gestation) or with extremely low birth weight (ie. &lt1000 grams) are at high-risk of major and minor motor sequelae that persist into the school years. Most of the research on the outcome of these high-risk infants has concentrated on the prevalence of major disability. The majority of high-risk children at school age have normal intelligence and no sensorineural disability. Despite this, these ???apparently normal??? high-risk children have a higher incidence of minor morbidities. Motor coordination problems are frequently reported, yet further investigation into the emergence of minor motor dysfunction, or its impact on academic achievement and everyday activities is seldom explored. The aim of this thesis was to provide a comprehensive investigation into motor dysfunction, which is commonly found in ???apparently normal??? high-risk children. This was addressed in a series of five studies that intended to provide insight into the emergence, prevalence, nature, and prediction of motor dysfunction in otherwise ???normal??? high-risk children. Study 1 examined the development of gross and fine motor skills from infancy to school age using a longitudinal cohort study design. ???Apparently normal??? high-risk children (n=58) were assessed with the Peabody Developmental Motor Scales at 18 months corrected age, 3 and 5 years. A significant proportion continued to have fine motor deficits to school age (64%), reflecting a persistent problem with fine motor skills throughout this period. The proportion of infants with gross motor deficits significantly increased from 18 months to 5 years (81.1%), particularly for the ???micropreemies???. Whilst there was no gender difference found, the development of gross and fine motor skills appeared to be influenced differently by the home environment. Study 2 examined the impact of motor dysfunction on performance at school age. The prevalence of Developmental Coordination Disorder (DCD) in ???apparently normal??? high-risk children was determined using a controlled cohort study design. In addition, the nature of DCD in this population was explored by testing sensorimotor abilities that possibly underlie the motor dysfunction. Fifty (50) high-risk children with IQ&lt85 and no identified sensorineural disability were assessed at 8 years of age along with a matched control from their respective class at school. The Movement Assessment Battery for Children and a battery of sensorimotor tests were administered. Results indicated a significantly higher prevalence of DCD (42%) in the high-risk group in comparison to the control group (8%). In relation to sensorimotor abilities that may influence motor performance, the high-risk group scored significantly lower on most of tests, however it was neurological ???soft signs???, postural praxis, and sequencing praxis that contributed to DCD in the high-risk group. Study 3 was designed to investigate the impact of motor dysfunction on a motor-based task performed within the school setting. Specifically, this study described handwriting skills in ???apparently normal??? high-risk children, determined the prevalence of handwriting dysfunction, and investigated sensorimotor abilities that may be associated with problematic handwriting. The high-risk cohort and matched controls described in study 2 were also administered a number of handwriting tests. High-risk children were found to have poorer handwriting legibility and speed in comparison to their classmates. The prevalence of handwriting dysfunction in the high-risk group was 46%, significantly higher than controls (18%). Hand preference, pencil grasp used, and pain whilst writing were comparable to the control group. The contribution of underlying sensorimotor abilities to handwriting dysfunction in the high-risk population however was not evident. By using the same subjects in studies 2 and 3, the co-morbidity of handwriting dysfunction with DCD could be determined. Of those high-risk children identified with DCD, 43% had co-morbid handwriting dysfunction. Study 4 explored the relationship between perinatal and environmental variables to Developmental Coordination Disorder and handwriting dysfunction in high-risk children. Perinatal and environmental variables of the 50 ???apparently normal??? high-risk children that participated in the previous study were analysed. Results indicated prolonged rupture of membranes (PROM) and retinopathy of prematurity (ROP) were significantly and independently associated with DCD, perhaps reflecting the impact of the antenatal infection process and visual development related to ROP on motor outcome in high-risk children. Perinatal variables were not associated with handwriting dysfunction, but high-risk males were more likely to have handwriting dysfunction. Maternal education and paternal occupation were associated with aspects of handwriting. Whilst handwriting is a motor-based activity, it appears to be influenced by environmental variables, similar to other academic areas for the high-risk population. Study 5 sought to determine whether a motor assessment at an earlier age could predict DCD in the ???apparently normal??? high-risk population at school age. Motor assessment at 12 months, 3 and 5 years for the high-risk subjects who participated in study 2 were analysed using Receiver Operator Curves (ROC curves). The 3 year assessment with the Peabody Developmental Motor Scales was the best predictor of DCD at 8 years, with the Griffiths Locomotor Scale at 3 years yielding a similar result. Findings suggest that high-risk children who scored below the specified cut-off points on 3 year motor assessments and who had a history of PROM or ROP were at greater risk of having motor-based problems that had the potential to interfere with functioning at school.

xiv, 228 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D. 1972) from the Dept. of Child Health, University of Adelaide

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 96-108).