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1.
Phyllis W Sharps Ayman A E El-Mohandes M Nabil El-Khorazaty Michele Kiely Tessa Walker 《Journal of perinatology》2003,23(5):414-419
OBJECTIVE: To describe breastfeeding initiation among 210 urban African-American mothers with inadequate prenatal care. METHODS: This study is a case-control study of postpartum mothers recruited from four large urban hospitals. RESULTS: Mothers who chose to breastfeed were more educated, employed before birth, married, and using contraception postnatally. Regression model analysis controlling for demographic differences revealed that breastfeeding was significantly associated with a higher perception of severity of illness and higher confidence in the ability of health care to prevent illness. Breastfeeding mothers were less likely to reverse parent-child roles and had a lower perception of hassle from their infant's behavior. When comparing mothers who breastfed longer than 8 weeks to those who did not breastfeed, breastfeeding mothers had high scores related to empathy toward infants on the Adult-Adolescent Parenting Inventory as well as a low perception of hassle on the Parenting Daily Hassle. The perception of existing formal or informal social support did not influence breastfeeding behavior. CONCLUSION: Personal attributes of low-income urban mothers such as health beliefs and parental attitudes may play a role in the initiation and duration of breastfeeding. Low-income African-American mothers may be influenced in their choice to breastfeed by supportive messages from physicians and nurses delivering care to mothers and their newborns. Emphasis should be placed on the role breastfeeding can play in preventing childhood illnesses. 相似文献
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1. The sensitivity to acetylcholine (ACh) of the fast posterior latissimus dorsi (PLD) and slow anterior latissimus dorsi (ALD) during embryonic development was studied and compared. The sensitivities were expressed as a ratio of the maximal tetanic tension and tension developed in response to ACh. 2. Up to the 17th day of incubation both muscles are sensitive to ACh to a similar extent; at the 18th day the sensitivity of the PLD muscle decreases and continues to do so until hatching and thereafter. 3. Since the decrease in sensitivity of PLD muscles takes place a few days after innervation, it is suggested that this is caused by activity of the motor nerve. To test this curare (dTc) and hemicholinium (HC-3), drugs that interfere with neuromuscular transmission, were injected into the yolk sac of the embryos when nervemuscle connections are usually established. In the curare and HC-3 treated embryos the desensitization of the PLD muscles did not take place. 4. The distribution of endplates on PLD muscles from drug treated 20-21 day old embryos was compared to that of untreated controls. Whereas control PLD muscles have only one band of endplates, muscles from curarized embryos and HC-3 treated embryos have several bands of endplates, and many muscle fibres with multiple innervation were found. 5. It is suggested that nerve fibres which make connections with PLD muscle fibres bring about a decline in chemosensitivity by releasing more transmitter, and thereby prevent further nerve muscle connections from being made along the same muscle fibre. 相似文献
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Dejan Popovic Tessa Gordon Victor F. Rafuse Dr. Arthur Prochazka 《Annals of biomedical engineering》1991,19(3):303-316
Implanted wire electrodes are increasingly being used for the functional electrical stimulation of muscles in partially paralysed
patients, yet many of their basic characteristics are poorly understood. In this study we investigated the selectivity, recruitment
characteristics and range of control of several types of electrode in triceps surae and plantaris muscles of anaesthetized
cats. We found that nerve cuffs are more efficient and selective (i.e., cause less stimulus spread to surrounding muscles)
than intramuscular electrodes. Bipolar intramuscular stimulation was more efficient and selective than monopolar stimulation,
but only if the nerve entry point was between the electrodes. Monopolar electrodes are efficient and selective if located
close to the nerve entry point, but their performance declines with distance from it. Nonetheless, for a variety of reasons
monopolar stimulation provides the best compromise in many current applications. Short duration pulses offer the best efficiency
(least charge per pulse to elicit force) but high peak currents, increasing the risk of electrode corrosion and tissue damage.
Electrode size has little effect on recruitment and should therefore be maximised because this minimises current density. 相似文献
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Tessa A Giannotti A Tieri L Vilarinho L Marotta G Santorelli FM 《European journal of human genetics : EJHG》2001,9(2):147-149
Hearing loss is a relatively frequent defect in children with a genetic or predisposition basis in about 50% of cases. Mitochondrial DNA (mtDNA)-associated disorder often present with sensorineural hearing loss (SNHL) either in isolation or as a part of a multisystem disorder in adults but the frequency in pediatric cases is unknown. We analysed deafness-related mtDNA mutations in 80 deaf children to assess the relative frequency of alterations in childhood-onset SNHL. In 16 patients in whom maternal inheritance was possible, we screened for new mutations likely to affect mitochondrial protein synthesis. In one child we detected a novel mutation (T1095C) in the 12S rRNA gene. This mutation fulfils the suggested criteria for definition of a disease-related nucleotide variant. No mutations were found in other patients. Although we cannot exclude the presence of still undefined new mtDNA mutations, our data suggest that mtDNA defect are not common in childhood-onset SNHL. 相似文献
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Peasgood Tessa Chang Jen-Yu Mir Robina Mukuria Clara Powell Philip A. 《Quality of life research》2021,30(7):2097-2108
Quality of Life Research - Uncertainties exist in how respondents interpret response options in patient-reported outcome measures (PROMs), particularly across different domains and for different... 相似文献
10.
David Hill Victoria White Tessa Letcher 《Australian and New Zealand journal of public health》1999,23(3):252-259
OBJECTIVES: To estimate smoking prevalence among Australian secondary students in 1996 and to examine trends in smoking prevalence since 1984. METHOD: A randomly selected representative sample of 434 secondary schools from across Australia participated in the study. At each school 80 randomly selected students completed a pencil-and-paper questionnaire anonymously. Data from 29,850 students aged between 12 and 17 years are reported. RESULTS: Current smoking (smoking in the week before the survey) was 8% in boys and 7% in girls aged 12, and rose to a peak prevalence among 17 year olds of 28% for boys and 34% for girls. The mean number of cigarettes smoked per week among current smokers rose from 11 for boys and six for girls aged 12 to 37 for boys and 34 for girls aged 17. Comparisons across survey years showed that while fewer 12 to 15 year olds were current smokers in 1996 than in 1984, the proportion in 1996 was greater than that in 1987 or 1990. Among 16 and 17 year olds, the proportion of current smokers in 1996 was greater than that seen in 1987 or 1990. An aggregate measure of tobacco involvement suggested that involvement with tobacco had remained stable since 1993 among 12 to 15 year olds. CONCLUSION: The decline in adolescent smoking seen in the late 1980s has stopped. IMPLICATIONS: Extrapolating from this survey, we estimate that more than 276,000 12-17 year old students were current smokers in 1996. If they all continue to smoke, 138,000 would die prematurely. 相似文献