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Postnatal undernutrition: an alternative method.

Rat pups were undernourished from birth by placing them for 12 hr/day with a normal lactating mother and 12 hr/day with a nipple-ligated mother each day for 25 days. The method resulted in a marked delay in the body growth of the undernourished pups, especially during the first 2 weeks of life. Observations of the behavior of the mothers towards the underfed pups were made at different times of the day and compared to the behavior of the mothers suckling well-fed pups. The results show that (1) nipple-ligated mothers are able to provide adequate maternal care for undernourished pups, and (2) both ligated and nonligated mothers caring for underfed pups spend more time with those pups than mothers caring for well-fed pups.

Age Factors↗

PCBs, thyroid hormones, and ototoxicity in rats: cross-fostering experiments demonstrate the impact of postnatal lactation exposure.

Previous research has demonstrated the sensitivity of the developing rat to the hypothyroxinemic and ototoxic effects of perinatal exposure to Aroclor 1254 (A1254). We tested the hypothesis that postnatal exposure via lactation is the major cause of the ototoxicity by cross fostering animals at birth. Primiparous rats (22-24/dose) received 0 or 6 mg/kg A1254 (po in corn oil) from gestation day (GD) 6 to postnatal day (PND) 21. On the day of birth, half of the treated litters and half of the control litters were cross-fostered, resulting in the following groups: Ctrl/Ctrl (controls); A1254/A1254 (perinatal exposure); A1254/Ctrl (prenatal exposure only); and Ctrl/A1254 (postnatal exposure only). We assessed offspring at a number of ages for: serum thyroid hormone concentrations, liver and brain concentrations of PCBs, body weight, mortality, age of eye opening, auditory startle amplitudes, and auditory thresholds for 1 kHz and 40 kHz tones. Circulating thyroxine (T(4)) concentrations were sharply reduced at GD 21 in the A1254-exposed group, and on PND 3, 7, 14, and 21 in the A1254/A1254 and the Ctrl/A1254 groups. Smaller decreases in T(4) were observed in the A1254/Ctrl group on PND 3, 7, and 14. PCB concentrations in the liver on PND 21 were sharply elevated in the A1254/A1254 and Ctrl/A1254 groups. Much smaller increases were seen in the A1254/Ctrl group. Age of eye-opening and startle amplitudes were unaffected by treatment. A1254 exposure caused permanent hearing deficits (20 dB increase) at the low frequency (1 kHz) in the A1254/A1254 and Ctrl/A1254 groups. The present findings demonstrated that the critical period for the ototoxicity of developmental A1254 exposure is within the first few postnatal weeks in the rat. This effect is consistent with the greater degree of postnatal hypothyroxinemia resulting from the greater magnitude of exposure that occurs postnatally via lactation.

Aging↗

Clinical value of prolactin bioassay in euprolactinemic reproductive disorders.

To examine the disparity between clinical presentation and prolactin (PRL) measured by radioimmunoassay (RIA), serum samples from 128 patients with galactorrhea and/or reproductive disorders were evaluated by RIA for immunoassayable PRL (RIA-PRL) and by Nb2 lymphoma cell proliferation assay for bioassayable PRL (bioassay-PRL). One hundred fifteen patients had normal RIA-PRL and 13 patients had high RIA-PRL (greater than 25 ng/ml). Twenty patients had galactorrhea, two of whom had hyperprolactinemia. The reproductive disorders in female patients included infertility, amenorrhea, oligomenorrhea, irregular menstrual cycles, and luteal phase defects. Six oligospermic males also were studied. Twenty-three male and female volunteers with no evidence of reproductive disorders served as controls. Appropriate comparisons showed that PRL bioassay/RIA ratio, an index of agreement between the two assay systems, did not differ for the various patient groups compared with controls. It is concluded that Nb2 lymphoma bioassay does not provide additional diagnostic value to RIA in defining the cause of euprolactinemic galactorrhea and/or reproductive disorders.

Biological Assay↗

Influence of sire and sire breed (Gyr versus Holstein) on establishment of pregnancy and embryonic loss in lactating Holstein cows during summer heat stress.

Heat stress has negative effects on pregnancy rates of lactating dairy cattle. There are genetic differences in tolerance to heat stress; Bos taurus indicus (B. t. indicus) cattle and embryos are more thermotolerant than Bos taurus taurus (B. t. taurus). In the present study, the effects of sire and sire breed on conception and embryonic/fetal loss rates of lactating Holstein cows during the Brazilian summer were determined. In Experiment 1, cows (n=302) were AI after estrus detection or at a fixed-time with semen from one Gyr (B. t. indicus) or one Holstein sire (B. t. taurus). Pregnancy was diagnosed 80 days after AI. In Experiment 2, cows (n=811) were AI with semen from three Gyr and two Holstein sires. Pregnancy was diagnosed at 30-40 and at 60-80 days after AI. Cows diagnosed pregnant at the first examination but non-pregnant at the second were considered as having lost their embryo or fetus. Data were analyzed by logistic regression. The model considered the effect of sire within breed, sire breed, days postpartum, period of lactation, and AI type (AI after estrus versus fixed-time). There was no effect of the AI type, days postpartum or milk production on conception or embryonic loss rates. The use of Gyr bulls increased pregnancy rate when compared to Holstein bulls [9.1% (60/657) versus 5.0% (23/456), respectively, P=0.008; data from Experiments 1 and 2 combined]. Additionally, in Experiment 2, cows inseminated using semen from sire #4 (Gyr) had lower embryonic loss (10%) when compared with other B. t. indicus (35.3% and 40%) or B. t. taurus sires (18.2% and 38.5%, P=0.03). In conclusion, the use of B. t. indicus sires may result in higher conception rates in lactating Holstein cows during summer heat stress. Moreover, sire can affect embryonic loss and selection of bulls according to this criterion may result in higher parturition rates in lactating Holstein cows.

Abortion, Veterinary↗

Impaired mammary function and parathyroid hormone-related protein during lactation in growth-restricted spontaneously hypertensive rats.

Evidence implicates pivotal roles for parathyroid hormone-related protein (PTHrP) during lactation, including stimulation of mammary and pup growth. As spontaneously hypertensive rat (SHR) pups are growth restricted compared with the control Wistar Kyoto (WKY), we examined the relative roles of pup suckling and maternal lactational environment on pup growth, mammary PTHrP, and milk PTHrP and calcium concentrations. SHR pups were lighter compared with the control from 6 days. SHR mammary PTHrP content and milk PTHrP were lower but maternal plasma PTHrP was raised compared with WKY. SHR mammary morphological development was also impaired compared with control. Cross fostering growth-restricted pups onto WKY mothers increased pup weight in association with normal mammary function and higher milk PTHrP and calcium. Control pups suckling on an SHR mother had reduced body weight. Both cross fostering groups were associated with increased maternal and milk PTHrP concentrations, indicating the importance of suckling, together with a functional mammary gland. The results suggested that impaired SHR mammary function and milk PTHrP are associated with a reduced SHR postnatal growth. Our data also indicated that milk and mammary PTHrP are regulated by different mechanisms but that they are influenced by the maternal lactational environment and the suckling pup.

Animals↗

A case of prolactin deficiency with familial puerperal alactogenesis accompanying impaired ACTH secretion.

We report here the case of a 34-year-old female with puerperal alactogenesis. Her menstrual cycle was regular and breast development normal. She had delivered a healthy boy but could not breast-feed after parturition. Endocrinological studies disclosed that the cause was a prolactin (PRL) deficiency. In addition, she showed accompanying impaired ACTH secretion that was believed to be triggered by encephalitis, although her plasma levels of GH, TSH, LH and FSH remained intact. Pituitary MRI showed no specific findings and anti-pituitary antibody tests were negative. Interestingly, both her mother and grandmother also reported puerperal alactogenesis. The sequences of all five exons of the PRL gene, including promoter region and transcription initiation point, were surveyed in order to examine for certain genetic disorders, but no mutations were identified. Although it cannot be definitively concluded that this PRL deficiency was not a genomic DNA disorder, in our case at least, her PRL gene was normal and, therefore, was not directly responsible for the patient's impaired PRL secretion. This evidence suggests that familial puerperal alactogenesis and PRL deficiency can be induced by other causes such as via disorders of unknown transcription factors or molecules that contribute to translation of PRL gene.

Adrenocorticotropic Hormone↗

Dynamics of Prl release in galactorrhoeic normoprolactinaemic women.

Prl responsiveness to TRH and sulpiride was evaluated in 14 galactorrhoeic normoprolactinaemic women. Radiological signs of sellar alteration were present in 6 of these patients. Pituitary responses to TRH did not differ from those obtained in a group of 16 healthy women. Serum Prl levels after sulpiride were higher in the patients than in the controls (P less than 0.01). The delta max response was 256 +/- 16 SE vs 158 +/- 10.6 ng/ml in the control group (P less than 0.01). The mean integrated area after sulpiride was also greater 20738 +/- 1263 SE ng/ml/2 h vs 13 188 +/- 408) (P less than 0.01). The markedly enhanced Prl response to sulpiride in our patients with galactorrhoea could be due to a functional disorder of the hypothalamic-pituitary axis or to a lactotrope hyperplasia.

Adult↗

Strategies for managing reproduction in the heat-stressed dairy cow.

Establishment and maintenance of pregnancy is difficult in lactating dairy cows exposed to heat stress because of reductions in estrous detection rate and the proportion of inseminated cows that maintain pregnancy. The most common approach to ameliorate heat stress in developed countries has been to alter the cow's environment through provision of shade, fans, sprinklers, and so on. Nonetheless, seasonal variation in reproductive function persists. Increased understanding of bovine reproductive function and its alteration by heat stress has led to additional strategies for reducing deleterious consequences of heat stress on reproduction. These include hormonally induced timed artificial insemination, which can reduce losses in reproductive efficiency caused by poor detection of estrus, and embryo transfer, which can increase pregnancy rate by allowing embryos to bypass the period when they are most sensitive to elevated temperature (i.e., in the first 1 to 2 d after breeding). Other efforts are directed toward developing methods to protect the embryo from harmful actions of elevated temperature. Approaches being studied include manipulation of embryonic synthesis of heat shock proteins and use of antioxidants to reduce free radical damage associated with heat stress. It may also be possible to reduce the magnitude of hyperthermia caused by heat stress. This might be possible physiologically, for example by feeding of agents that affect thermoregulatory systems, or genetically by selecting for specific traits conferring thermal resistance. Finally, the development of bovine somatotropin as a lactational promotant means that it may be possible to extend lactations beyond 305 d and voluntarily discontinue inseminations during periods of heat stress.

Animals↗

Pregnancy following 2-bromo-alpha-ergocryptine (CB-154)-induced ovulation in an acromegalic patient with galactorrhea and amenorrhea.

An acromegalic patient with galactorrhea-amenorrhea who conceived following long-term 2-bromo-alpha-ergocryptine (CB-154) therapy is described. During CB-154 therapy, determinations of serum prolactin (PRL), luteinizing hormone (LH)-human chorionic gonadotropin, follicle-stimulating hormone a reduction in PRL level followed by an LH peak, a rise in basal body temperature and menstruation. The patient became pregnant during the next cycle, but therapeutic abortion was performed because of the active acromegaly. These results demonstrate that CB-154 can restore ovulatory function not only to the patient with a hypothalamic disorder but also to the acromegalic patient with an enlarged sella turcica.

Acromegaly↗

Investigations of milk quality from teats with milk flow disorders.

The objective of this study was to investigate the quality of milk from teats with milk flow disorders. Somatic cell count, pathogens, and signs of mastitis (>100,000 cells/ml and pathogens detected) were determined in the milk from all teats of the udder before treatment of the affected teat, as well as 1 and 6 mo later. Teats with milk flow disorders were compared to all of the other teats from the same udder. Before treatment, the SCC from affected teats was 4.3 million higher, the odds of detecting pathogens 6 times higher, and the odds of mastitis 11 times higher than in control teats (when adjusted for other significant explanatory variables). SCC and the risk of mastitis decreased after surgical treatment of the affected teats, whereas the chance of detecting pathogens was not affected. Six months after treatment, the SCC was 1.3 million higher, and the odds of mastitis 6.5 times higher than in control teats. Throughout the study period neither SCC, the odds of detecting pathogens, nor mastitis changed significantly in control teats. It may be concluded from this study that milk quality from teats with milk flow disorders is decreased before treatment and does not reach the milk quality from unaffected teats within 6 mo after treatment.

Animals↗

Genetic basis and risk factors for infectious and noninfectious diseases in US Holsteins. I. Estimation of genetic parameters for single diseases and general health.

Health data collected from 1996 to 1999 from 177 herds in Minnesota and Wisconsin were analyzed to establish genetic basis for infectious and noninfectious diseases. Three types of health traits were targeted. First, available infectious conditions were used to identify animals that are superior in their general immunity (including innate immunity) for infectious diseases. Generalized immunity may be thought of as a combination of immune responses to a variety of immune system challenges. Second, single infectious and noninfectious diseases were analyzed separately. Third, infectious reproductive diseases as one category of related conditions, and cystic ovary disease as one category of 3 related noninfectious ovary disorders were studied. Data were analyzed using a threshold model that included herd, calving year, season of calving, and parity as cross-classified fixed factors; and sire and cow within sires as random effects. Days at risk and days in milk at the beginning of a record were included by fitting the days as continuous covariates in the model. A heritability value of 0.202 +/- 0.083 was estimated for generalized immunity. Heritability values of 0.141 and 0.161 were estimated for uterine infection and mastitis, respectively. Heritability of single noninfectious disorders ranged from 0.087 to 0.349. The amount of additive genetic variance recovered in the underlying scale of noninfectious disorders tended to zero when combining multiple conditions. The study supports combining infectious diseases into categories of interest but we do not recommend the same approach for noninfectious disorders.

Abomasum↗

[State of cerebral functions in the persistent lactorrhea-amenorrhea syndrome].

A complex investigation of the brain functions of patients with the idiopathic persisting lactorrhea-amenorrhea syndrome (PLAS) revealed a series of nonspecific changes. Insufficiency of the activating systems was shown according to the EEG data. Anxious depression was also seen. The examination of the vegetative nervous system during relaxation and exercises is indicative of insufficient activity of its symptomatic region. Thereafter, specific neurosecretory deficit in the tuberous infundibular system and disorder of the brain activity, probably resultant of dopamine deficiency are seen in patients with PLAS.

Adult↗

Prevalence of Giardia lamblia antibodies in serum and milk in lactating women from different social classes in Egypt.

Prevalence and levels of systemic and milk antibodies to G. lamblia in the different social classes of the population were studied using the IFAT and nor-partigen immunoglobulin plates. Blood and milk samples were collected simultaneously from lactating women in urban (Cairo) and rural (Benha) areas. Serum IgG was present in 90% of rural low standard mothers, 58% of urban moderate standard mothers, and 25% or urban high standard mothers (P less than 0.01, P less than 0.001 and P less than 0.01). Antilog of mean of antibody titers was significantly higher in the low standard rural mothers than in the urban moderate and high standard ones. Specific secretory IgA antibody in milk was found in 71% of rural low standard mothers, 31% of urban moderate standard mothers, and 16.6% of urban high standard mothers (P less than 0.001, P less than 0.01 and P greater than 0.05). The antilog of mean S-IgA titers was also higher in the low standard rural mothers. The titer levels of S-IgA in the three classes did not show any correlation with the quantitative levels of total IgA in milk, while specific IgG showed a positive correlation with the total serum IgG in the low standard rural mothers only (P less than 0.05). This study documented the widely different antibody response to G. lamblia in individuals living in different social classes.

Animals↗

Lactation and prolactin release in foster dams suckling prenatally ethanol exposed pups.

The effect of prenatal ethanol exposure on lactation was studied employing prenatally ethanol-exposed pups transferred to foster dams following parturition. During pregnancy, from day 8 to term, dams consumed either standard laboratory chow (ad libitum control), or liquid diets containing 0%, 17.5%, or 35% ethanol derived calories (EDC). To equalize caloric intake, the 0% and 17.5% EDC groups were pair-fed to rats in 35% EDC group. Following delivery, pups born to dams fed with laboratory chow (control) or liquid diets containing 0, 17.5, or 35% EDC were adjusted to eight per litter and transferred to foster dams, which had been fed laboratory chow and water ad libitum throughout pregnancy. Foster dams were implanted with an atrial catheter on day 3 of lactation. On days 6 (early lactation) and 10 (midlactation), following separation of litters from dams for a 6-hr period, a baseline blood sample was removed via a catheter extension. Pups were weighed and returned to the dams. Subsequent blood samples were obtained 10, 30, 60, 120, and 180 min after initiation of suckling. Suckling latency and the amount of milk consumed during the 3-hr suckling were also determined. Litters were weighed on days 2, 6, 10, and 21. The prolactin surge in foster dams in response to suckling by prenatally ethanol-exposed pups was not altered on day 6 of lactation. On day 10, after the initial rise, suckling-induced prolactin was amplified in dams suckled by prenatally ethanol-exposed pups.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗

Unilateral breast dysfunction in lactating Gambian women.

Approximately 3% of lactating women in a rural Gambian village displayed long-term unilateral breast dysfunction as evidenced by abnormal milk composition and virtual cessation of suckling by the infant. This paper presents case histories of four such women studied over two successive lactations. The average breast-milk output of these women did not differ significantly from the mean value for the remainder of the community, indicating that the non-affected breast was usually able to compensate for the dysfunction. This was confirmed by the fact that the child-rearing record of three of the four women was better than the community average. In two of the women the breast which was dysfunctioning in one lactation reverted completely to normal for the next lactation. It is suggested that in such cases the dysfunction is self-perpetuating and may be alleviated by counselling mothers to persevere with feeding from the affected breast.

Adult↗

Prolactin and growth hormone responses in the amenorrhea-galactorrhea syndrome.

Fifteen patients with hyperprolactinemia, amenorrhea, and galactorrhea were studied; 10 of these patients had apparent tumors. Nine of 12 patients had a suppression of prolactin with oral L-dopa, and all of 4 patients undergoing dopamine infusion had suppression of prolactin. Eleven and 8 patients underwent chlorpromazine stimulation and insulin-induced hypoglycemia, respectively; none responded. Three of the 4 patients did not show a growth hormone response with dopamine infusion, and L-dopa testing failed to achieve a growth hormone response in 7 of 10 patients. The data suggest an intact dopaminergic inhibition of prolactin with exogenous agents. However, inhibition of endogenous dopamine by chlorpromazine failed to elicit a prolactin response. The disordered growth hormone response to dopaminergic agents suggests a central disorder of dopamine generation. The possible implication of these results with respect to the pathogenesis of hyperprolactinemia is discussed.

Amenorrhea↗