PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Lactation, Prolonged”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed2002

Improvement of rat liver graft function after storage in University of Wisconsin solution containing testicular hyaluronidase.

Hyaluronan accumulates at sites of inflammation, which affects the organization of matrix and thereby the proliferation, migration, and adherence of cells. In this study we investigated possible beneficial effects of the hyaluronan-degrading enzyme hyaluronidase on rat liver graft viability. Orthotopic rat liver transplantation was performed using a cuff technique in Wistar AL Bacharach Glaxo (WAG) rats grafted with WAG livers, which had been stored in the University of Wisconsin (UW) solution or in UW solution enriched with testicular hyaluronidase. Liver tissue architecture, as well as tissue and serum hyaluronan levels, were determined using immunohistochemistry and biochemical assays. Addition of testicular hyaluronidase (0.4 mg/mL) to livers preserved for 24 hours in cold UW solution followed by brief exposure to Ringer's lactate both prolonged the function of the grafted livers and improved their viability (4 of 10 grafts survived, compared with 0 of 10 in the control group). Hyaluronidase treatment did not damage the liver tissue architecture, and a reduced edema was observed in the survivors. Furthermore, 10 minutes after restoration of circulation, higher serum hyaluronan levels were observed in nonsuccessful compared with successful transplantations, whereas no differences in the levels of other serum viability markers were detected. We conclude that addition of testicular hyaluronidase to storage UW solution limits liver cell damage and considerably improves graft function. Furthermore, our data suggest that serum hyaluronan level is a better marker than other serum markers for early evaluation of postoperative graft function.

Adenosine↗
PubMed1993

[The risk of conception during lactation].

The contraceptive effect of lactation is undisputed. Nursing increases the prolactin level in the serum. This hyperprolactinaemia suppresses all levels of the hypothalamus-hypophysis-ovary axis. The risk of ovulation can be greatly reduced by a proper nursing routine, frequency of nursing being credited with a greater anovulatory effect than duration of nursing. In addition, full nursing increases contraceptive safety. To prevent a drop in the serum prolactin level, nursing should also be done at night-time. Amenorrhoea during the lactation period is one of the most important prerequisites for an adequate contraception. The risk of ovulation increases dramatically, if vaginal bleeding occurs. However, the first cycles in the lactation period are often anovular and characterized by corpus luteum insufficiency. Lactation-induced amenorrhoea, nursing frequency of at least 6 x/day, nursing duration of at least 60 minutes/day, additional feedings of maximum 1 x/day and nocturnal nursing are the requirements for sufficient nursing-induced contraception. Even if these requirements are fulfilled, the risk of ovulation increases with the length of time post partum. Effective contraceptive protection is attained only up to the 9th p.p. week. If high post partum contraceptive safety is required, a mini-pill or micro-pill must be recommended. Lactation can only be recommended as a moderate contraceptive measure even in this case, an additional method (chemico-mechanical) should be initiated 3 months post partum.

Adult↗
PubMedDate not supplied

Individual and community characteristics influencing breastfeeding duration in Vietnam.

This analysis of selected community and maternal characteristics influencing duration of breastfeeding in Vietnam utilized data from the 1988 Demographic and Health Survey and 1990 Accessibility of Contraceptives Survey available for the 4434 children born to 2769 women having their last birth between 1983-88. Explanatory variables included as covariates in the hazards model were mother's education, age of the mother at the time of the child's birth, birth order, and gender of the child, urban versus rural residence, infant mortality risk in the child's province, locality (mountains and highlands compared to delta and coastal), and region of the country (north, south). Indicators of development in the child's village included availability of electricity and public transportation. Breastfeeding duration was longer among the more highly educated women and among those women living in provinces with higher infant mortality. However, there were no significant differences in the duration of breastfeeding with variations among certain development characteristics of the village. Although there were regional differences in the duration of breastfeeding for the rural population, there were no regional differences for the overall population. There were no significant variations in the duration of breastfeeding by age of the mother, birth order or gender of the child. Although there were significant variations in duration of breastfeeding by some maternal and community characteristics, between 80-90 per cent of all women breastfeed for at least the first year of the child's life.

Adolescent↗
PubMedDate not supplied

Reproductive change in Sri Lanka: analysis of intermediate variables, 1982 and 1987.

This study examines the intermediate determinants of fertility in Sri Lanka by making use of the data collected in the 1982 Sri Lanka Contraceptive Prevalence Survey and the 1987 Sri Lanka Demographic and Health Survey. The analysis shows that the most important inhibitor of potential fertility is deliberate control. The marital structure of the population is also an important fertility-inhibitor, but lactational infecundability is increasingly becoming an unimportant contributor. The findings show the success of the family planning program in Sri Lanka, which propelled fertility to a substantial lower level. Achievement of the replacement level fertility by the turn of the century, set by the Sri Lankan government, would largely depend on the efforts to increase the quality and quantity of contraceptive use and the duration of breastfeeding.

Adolescent↗
PubMed1993

Suppression of B lymphopoiesis during normal pregnancy.

We describe a dramatic reduction in numbers and activity of committed B lymphocyte precursors in the bone marrow of normal pregnant mice. Changes in cells responsive to IL-7 were evident as early as 6.5 d of pregnancy and values were < 10% of normal at parturition. B lineage precursors, identified by display of CD45R and absence of surface IgM, were also substantially depressed, and subpopulations representing different stages in the B lineage were assessed by three-color flow cytometry. Early pro-B cells are medium to large in size and have been previously characterized by low expression of the heat-stable antigen (HSA). This category of cells was not reduced, and in fact may have been slightly elevated, during pregnancy. In contrast, all subsequent populations of B lineage precursors, defined by patterns of expression of heat-stable and CD43 antigens, were substantially depressed. The immediate precursors of B cells (small pre-B cells) were identified by small size, expression of CD45R, absence of CD43, and lack of surface IgM. These were the most reduced of any phenotypically defined population in bone marrow. Numbers of newly formed B cells, characterized by the presence of sIgM, but not sIgD, were also diminished. However, B cells with a mature phenotype (sIgM+, sIgD+) were present in normal to somewhat elevated numbers. Mitogen-responsive B cells clonable in a semisolid agar assay were not significantly affected. A bromodeoxyuridine (BrdU) labeling technique was used to evaluate mitotic activity, which revealed an increased proportion of long-lived lymphocytes in the bone marrow of pregnant mice. These observations indicate that B lymphopoiesis is markedly downregulated during pregnancy and that all precursor populations beyond the early pro-B cell stage are affected. The pregnancy-related changes in bone marrow were selective for B lineage precursors, as cells expressing myeloid and erythroid markers were not reduced. In spleen, evidence was obtained for partial depletion of one subset of B cells. These cells, which have been reported to be recent immigrants from marrow, are characterized as having high levels of sIgM and HSA. Changes in other major B lymphocyte subsets in the spleen were less remarkable. When considered with results from the BrdU labeling procedure, the findings indicate that both production and export of lymphocytes from marrow may be substantially decreased. Numbers of B cell precursors were higher in postpartum animals whose litters were removed at birth, suggesting that lactation may prolong regeneration of lymphocyte production.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1979

Studies on the quality of breast milk during 23 months of lactation in a rural community of the Ivory Coast.

Milk samples from 33 women from a rural area of the Ivory Coast were analyzed once a month. In two longitudinal studies covering 23 months of breast feeding, analyses of lipid components and protein were performed. The compositions remained virtually constant over 23 months of lactation except for a decrease of protein concentration during the first 6 months, a rising trend of myristic acid (14:0) and a falling trend of oleic acid (18:1). Infants were growing well on breast milk with nothing else for the first 5 months, but thereafter their growth curves were no longer satisfactory as judged by Western standards: weight for age (percentage of Harvard standards) decreased from 5 to 10 months of age to level off thereafter at a value of 80%. The mothers' weight for height remained constant. In a cross-sectional study, additional determinations were performed: aminograms, lactose, calories, iron, copper, manganese, zinc, and vitamin E. All data were compared with those of the literature. Lauric (12:0) and myristic (14:0) acids were higher, total lipids and polyunsaturated fatty acids lower than those published for Western countries. Plasma composition of the mothers showed lower levels of albumin, lipids, and polyunsaturated fatty acids as well as blood hemoglobin. Possible correlations between various variables such as milk composition, plasma levels, and anthropometry were calculated and discussed.

Aging↗
PubMed1979

Lactose malabsorption in Bangladeshi village children: relation with age, history of recent diarrhea, nutritional status, and breast feeding.

The prevalence of lactose malabsorption (LM) among Bangladeshi village children has been determined using the recent developed breath hydrogen test. Initial hospital-based comparison studies showed general agreement between the breath hydrogen test and a modified lactose tolerance test. Two hundred thirty-four children, stratified by age, nutritional status, and history of recent diarrhea then participated in the field study. LM was diagnosed in more than 80% of children over 36 months of age but in none of the children under 6 months. Rates of LM were significantly increased in children with a history of recent diarrhea and a greater proportion of children in some age groups evidenced malabsorption in association with acute undernutrition. In the weanling age group children who were still breast feeding had a lower rate of LM than fully weaned subjects.

Adolescent↗
PubMed1981

Protein and amino acids of breast milk from Thai mothers.

The protein, amino acids, and nonprotein nitrogen of milk samples obtained from Thai mothers over a period of 0 to more than 270 days postpartum were determined. Protein levels decreased from 1.56% during the 1st wk to a low of about 0.6% from 180 to 270 days and then rose to about 0.7%. The amino acid pattern of the milks suggested a number of differences in their composition and those of samples analyzed in other countries. Nonprotein nitrogen varied from 20 to 40% of the total nitrogen of the milk. It has been concluded that the need for supplementation of breast-fed Thai babies may occur earlier than many nutritionists advocate.

Amino Acids↗
PubMed1983

Growth pattern of selected urban Chilean infants during exclusive breast-feeding.

This report describes the growth pattern of healthy, low middle and low socioeconomic class Chilean infants during exclusive breast-feeding. Two-hundred forty-two infants who were on exclusive breast-feeding at day 30 postpartum entered the study. Of these, 59% were fully nursing at 6 months and grew at a normal rate without receiving either supplementary milk or nondairy food. Supplementary feedings were administered in 27% of cases because of suspected primary inadequate milk output and in 14% of cases for other reasons such as pregnancy, illness, maternal work, or self-prescription. Full nursing provided the highest rate of weight increase during the first 3 months of life and a greater weight gain for boys than for girls up to the age of 6 months. Gastrointestinal pathology, malnourishment, or hospitalization were rare events in this population. It is concluded that maternal milk alone, if produced in sufficient amounts, can maintain normal growth up to the 6th month of life. The study supports the choice of exclusive breast-feeding on demand plus child growth monitoring up to 6 months over routine prescription of supplements at earlier times particularly where supplement administration fails to meet individual requirements.

Adolescent↗
PubMed1990

Milk selenium of rural African women: influence of maternal nutrition, parity, and length of lactation.

The selenium content of milk samples from rural Gambian women (n = 55) was evaluated as a function of parity, stage of lactation, and maternal nutrition. Samples were collected during periods of relative food abundance (dry season) and food scarcity (rainy season). Milk selenium was lower (p less than 0.01) in the rainy than in the dry season (208 vs 256 nmol/L, respectively). Milk selenium was similar in samples from women in early (1-6 mo postpartum) and late (13-19 mo postpartum) lactation. During late lactation, parity, which ranged from 1 to 11, was negatively correlated with milk selenium regardless of plane of maternal nutrition (p less than 0.02). Measures of protein, glutathione peroxidase, and total peroxidase were not affected by stage of lactation or parity. Glutathione peroxidase activity accounted for 38% of the peroxidase activity in milk. Results show that although length of lactation alone had little impact, milk selenium secretion was influenced by both maternal nutritional adequacy and parity of rural Gambian women.

Chromatography, Gas↗
PubMed1996

Effect of skim milk supplementation of the maternal diet on lactational amenorrhea, maternal prolactin, and lactational behavior.

Effect of skim milk supplementation of the maternal diet on lactational amenorrhea was studied in 30 pairs of healthy lactating women matched for parity, body mass index, and previous experience of lactational amenorrhea. Supplementation of the maternal diet had no significant effect on the time of resumption of regular menstruation or ovulation, maternal prolactin concentrations, breast-feeding pattern, maternal body mass index, or infant weight. However, the supplemented group breast-fed nearly exclusively (supplemental feeds were introduced but did not exceed 20% of total feeds) for a significantly longer duration (P < 0.05) than did the control group. Previous experience of lactational amenorrhea was significantly positively correlated with the time of resumption of menstruation in the supplemented (P < 0.01) and control (P < 0.05) groups when frequency of breast-feeding, maternal body mass index, and supplementary feeds to the infant were controlled for. Thus, maternal nutritional supplementation does not appear to affect the contraceptive benefit of lactation when the frequency of breast-feeding is not compromised but apparently lengthens the duration of nearly full breast-feeding.

Adult↗
PubMed1997

Effects of age at introduction of complementary foods to breast-fed infants on duration of lactational amenorrhea in Honduran women.

Lactational amenorrhea (LA) is associated with postpartum infertility and is known to be related to breast-feeding frequency and duration, but the exact role of complementary feeding of the infant has not been clearly defined. Data on LA were collected during and after a 2-mo intervention trial in which low-income Honduran women who had breast-fed fully for 4 mo were randomly assigned to one of three groups: continued full breast-feeding until 6 mo (FBF, n = 50), introduction of complementary foods at 4 mo with ad libitum breast-feeding from 4 to 6 mo (SF, n = 47), or introduction of complementary foods at 4 mo with maintenance of baseline breast-feeding frequency from 4 to 6 mo (SF-M, n = 44). Women were followed up until the infant was 12 mo of age, or later if menses had not occurred by then. All but six of the women continued to breast-feed for > or = 12 mo. With the exclusion of those whose menses returned before 18 wk postpartum (which could not have been due to the intervention), the proportion of women who were amenorrheic at 6 mo was 64.5% in the SF group, 80.0% in the FBF group, and 85.7% in the SF-M group (chi-square test = 4.13, P = 0.02; one-tailed test with the latter two groups combined). The total duration of LA did not differ significantly among groups. The most significant determinant of LA was time spent breast-feeding (min/d), which was in turn negatively associated (P = 0.06) with the infant's energy intake from complementary foods in regression analyses. These results indicate that there is a significant effect of introducing foods at 4 mo on the likelihood of amenorrhea at 6 mo postpartum, but not thereafter, and that this effect is not seen in mothers who maintain breast-feeding frequency.

Adolescent↗
PubMedDate not supplied

Fertility regulating and immunotherapeutic vaccines reaching human trials stage.

The progress and current status of vaccines which induce antibodies against human chorionic gonadotrophin (HCG) and luteinizing hormone-releasing hormone (LHRH) are reviewed. Three vaccines devised against HCG have undergone phase I clinical trials documenting their safety, and reversibility. One of these, the heterospecies dimer (HSD)-HCG vaccine has also completed phase II efficacy trials in sexually active women of proven fertility. Immunization with the vaccine prevents pregnancy, as long as the antibody titres remain > or =50 ng/ml HCG bioneutralization capacity. There is no disturbance of menstrual regularity and women continue to ovulate normally. The antibody response is predominantly against an epitope in the core part of beta-HCG. Fertility is regained at titres <35 ng. These observations have laid the scientific foundations of a birth control vaccine. Research suggests the feasibility of making a cost-effective recombinant vaccine. The carriers tetanus toxoid (TT) and diptheria toxoid (DT) can be advantageously replaced by peptide determinants recognizing T, not B cells. In addition to optional fertility control, HCG vaccines may have tumour growth inhibition potential in lung cancers which produce HCG. The vaccine against LHRH can be used in both males and females. As it is a structurally conserved molecule, the same vaccine is applicable to both animals and humans. Antibodies against LHRH block the generation of gametes and sex steroids, with the result that the vaccine can be used for fertility control (domestic pets, prolongation of lactation amenorrhoea); as well as for sex hormone-dependent cancers. Phase I/phase II clinical trials have been conducted with the LHRH vaccine in advanced metastazing carcinoma of prostate patients with encouraging results. Bioeffective monoclonal antibodies have been developed against both LHRH and HCG. These can be 'humanized' and produced cost-effectively in bacteria and plants, thus paving the way for passive use of such antibodies for immunotherapy of cancers and fertility control.

Chorionic Gonadotropin↗