Ultrastructural identification of Ia positive dendritic cells in the lactating rat mammary gland

Summary Dendritic cells which express Ia antigen have been demonstrated for the first time in the lactating rat mammary gland. Ultrastructurally, the dendritic cells appear as electron-lucent pale cells interspersed among the epithelial cells of the alveoli, forming a cell population distinct from classical macrophages. They show morphological resemblance to the dendritic cells of lymphoid organs as well as the Langerhans cells of skin. The Ia antigen has been localised by electron microscopic immunocytochemistry on the cell membrane and endocytotic vesicles and tubules. Ia positive cells are also seen in the stroma of the mammary gland. It is proposed that the dendritic cells of the mammary gland belong to the lineage of epidermal Langerhans cells and lymphoid dendritic cells, subserving an immunological role in the lactating breast.     

Pituitary adenylate cyclase-activating polypeptide (PACAP) increases prolactin release and tuberoinfundibular dopaminergic neuronal activity

Pituitary adenylate cyclase activating polypeptide (PACAP) is a hypothalamic peptide that affects anterior pituitary cell function. This study examined the effects of PACAP on prolactin (PRL) release in vivo and on tyrosine hydroxylase (TH) activity in tuberoinfundibular dopaminergic neurons in vivo and in vitro. In ovariectomized rats, intravenous injection of PACAP increased circulating PRL levels 3-fold and TH activity in the stalk-median eminence (SME) by 30%. Incubation of the SME with 1 μM PACAP in vitro increased TH activity 2-fold. Intravenous infusion of ovine PRL (oPRL) by an osmotic mini-pump for 2 days in ovariectomized rats increased TH activity in the SME 1.7-fold and reduced circulating concentrations of endogenous rat PRL to 20% of control levels. PACAP induced a 4-fold rise in endogenous rat PRL levels in oPRL-treated rats and a 30% increase in TH activity that was additive to the elevation caused by hyperprolactinemia. In suckled lactating rats, PACAP did not alter circulating PRL levels or TH activity in the SME. When pups were removed from the dams for 4–5 h, systemic injection of PACAP stimulated PRL release without altering TH activity. However, PACAP, when administered in vitro, stimulated TH activity in the SME of lactating rats separated from their pups. These data indicate that PACAP may play a role in augmenting PRL release in female rats. The PACAP-induced rise in PRL release is modest and not due to a decrease in tuberoinfundibular dopaminergic neuronal activity. PACAP increases TH activity in the tuberoinfundibular dopaminergic neurons, possibly by a direct action on nerve terminals within the median eminence.     

Effect of calcium deprivation on rat dams on fetuses and newborn offspring

Summary Calcium-deficient rats were put to breeding, and fetuses and offsprings were collected at 18 daysin utero, at birth, and at 5–10 dayspost partum. Furthermore, blood and milk were collected from the dams, and blood from the offsprings. The rat pups had normal weights at 18 daysin utero and at birth, whereas at 5–10 dayspost partum the growth was significantly reduced. The relative amount of total solids in the body was also decreased at 5 and 10 dayspost partum (increased water content). Despite the fact that serum Ca in the dams was severely reduced, the calcium content in the serum of the offspring was only moderately lowered, and there was no correlation between serum Ca in dams and offspring. The content of total solids in the rat milk was increased, whereas the calcium content remained unchanged. The body content of Ca and P in the rat pups was decreased only at 5 and 10 dayspost partum. The degree of reduction was nearly the same for all these elements, amounting to 15–19% at 5 dayspost partum and 38–40% at 10 dayspost partum. If, however, the content of the elements was calculated as percentage of total body solids, a significant increase was found for all of them at 5 and 10 dayspost partum. Significant differences in Ca:P ratios were not found at any age.     

妊娠期及哺乳期妇女跟骨骨密度的超声定量监测

目的超声定量监测妊娠期及哺乳期妇女跟骨骨密度,研究妊娠及哺乳期妇女骨密度的变化规律,探讨超声监测的意义.方法采用MARCURY超声骨密度仪对41名孕16～20周,35名孕30～33周及36名产后40～60天(哺乳期)的健康妇女进行跟骨骨密度测定.结果孕16～20周,孕30～33周及产后40～60天妇女跟骨骨密度(BMD-H)依次降低为0.526±0.116g/cm2,0.503±0.083g/cm2,0.459±0.054g/cm2.超声传导速度(SOS)分别下降至1837±120.3m/s,1835±133.4m/s,1768±77.82m/s.BMD,SOS于孕30～33周出现降低,但较孕16～20周无统计学差异.产后40～60天哺乳期妇女跟骨BMD,SOS明显下降,较孕16～20周,孕30～33周妇女具有显著性差异(P<0.01).结论①骨量丢失贯穿于整个孕,产及哺乳期,骨密度的下降于孕后期及哺乳期达到统计学意义,故骨密度监测可始于孕后期(>33周).②超声骨密度测定因安全有效简便,作为妊娠期及哺乳期妇女骨密度定量监测,具有其独特的临床应用价值.     

Pharmacists and maternal-fetal medicine: development of a tool to characterize knowledge and current clinical practice

Abstract

Objective: To develop a knowledge assessment tool to assess baseline knowledge and current practice regarding maternal-fetal medicine.

Methods: A literature search was complemented with categorization of questions under five predefined domains related to maternal-fetal medicine. The final questionnaire was sent for expert review, cultural adaptation, and piloting, with feedback incorporated accordingly.

Results: A questionnaire was developed consisting of questions pertaining to demographics, knowledge, and current practice.

Conclusions: This tool is of interest to researchers, educators, and clinicians aiming to assess baseline knowledge, current curricula (both entry-to-practice and graduate) and continuing education opportunities for practicing pharmacists.     

Thyroid hormones and their correlations with serum glucose, beta hydroxybutyrate, nonesterified fatty acids, cholesterol, and lipoproteins of high-yielding dairy cows at different stages of lactation cycle

The relationships between circulating thyroid hormones and serum glucose, beta hydroxybutyrate (BHB), nonesterified fatty acid (NEFA), cholesterol and lipoproteins of high-yielding dairy cows were studied in 125 adult Holsteins at various stages of lactation cycle: early (far-off) dry period (n = 24), late (close-up) dry period (n = 10), fresh cows (n = 22), early lactation (n = 13), mid-lactation (n = 27) and late lactation (n = 29). Decreased levels of thyroxin (T₄) and triiodothyronine (T₃) were noted in peripartum cows which were extended to mid- and late-lactation cows, respectively. In fresh cows, glucose showed correlations with T₄ (r = 0.619, P < 0.01) and T₃ (r = 0.627, P < 0.01). In the same cows there were correlations between T₄ and BHB (r = 0.590, P < 0.01) and NEFA (r = 0.470, P < 0.01). In late dry cows, free thyroxin (fT₄) showed correlations with triglyceride (TG) and very-low-density lipoprotein (VLDL; r = −0.638, P < 0.05). Pooled data of the various stages of lactation cycle revealed correlations between glucose and T₄ (r = 0.20, P < 0.05), glucose and T₃ (r = 0.395, P < 0.01), cholesterol and T₃ (r = −0.201, P < 0.05), and free triiodothyronine (fT₃) and high-density lipoprotein (HDL; r = 0.178, P < 0.05). It appears that the time and the pattern of changes and/or correlations of serum thyroid hormones and lipid fractions may vary among dairy cows and other animals.     

Effect of Water Deprivation on Eating Patterns of Lactating Cows Fed Grass and Corn Pellets Ad Lib

The present study investigated the effect of 48 h of water deprivation on eating behavior of 12 lactating cows fed grass and corn pellets ad lib. Water deprivation reduced grass and corn pellet intake significantly, with corn pellet intake decreasing earlier than grass intake. The reduction of feed intake was entirely due to a reduction of meal size for both grass and corn-pellet meals. The size of the first meal of the water deprivation period was already reduced by about 30%. Grass-meal frequency increased, whereas corn-pellet meal frequency decreased during water deprivation. Water deprivation also decreased live weight and milk yield by about 12 and 30%, respectively. All parameters returned to baseline values with rehydration. With ad lib access to feed and water, 77% of drafts occurred in relation to meals, but the number of meals clearly exceeded the number of drafts. The results demonstrate that water deprivation rapidly leads to premature meal termination. This is in line with the assumption that an enhanced prandial increase in ruminal fluid osmolality contributes to dehydration-induced hypophagia. Yet, further studies are necessary to prove this assumption and to better understand the complex relationships between eating and drinking in ruminants.