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Hormonal physiology of lactation
Published in Nadia Barghouthi, Jessica Perini, Endocrine Diseases in Pregnancy and the Postpartum Period, 2021
Rawan El-Amin, Loren Custer, Jennifer Silk
Lactogenesis involves the onset of milk production and secretion secondary to maturation of alveolar milk-producing cells.The first stage begins with the morphologic differentiation of mammary epithelial cells during mid-pregnancy to support production of colostrum.2 This stage is inhibited from further progression by high levels of progesterone during pregnancy.The transition to stage two occurs at parturition when the placenta is delivered and levels of progesterone, estrogen, and human placental lactogen (hPL) decrease while prolactin levels remain high, possibly corresponding to increased cortisol and insulin levels. As the inhibitory influence of progesterone is no longer present, α-lactalbumin production increases. This stimulates the enzyme lactose synthase to increase lactose and milk production.3 Thyroid hormones can also enhance the secretion of lactalbumin.Stage two of lactogenesis can be altered in patients with diabetes, elevated cortisol induced by stress during late stages of labor, cesarean delivery, and retained products of conception including delayed placenta extraction.1
Assay of Antibiotics in Mammalian Cell Culture
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
The slope of the dose-response curve for certain pure compounds remains constant with changes in concentration and reflects the type of inhibition. The presence of other inhibitory agents or cell growth stimulants may alter the slope of the dose-response curve [4]. Time and temperature of exposure and the composition of the assay medium have been shown to effect the sensitivity of the assay to certain inhibitory agents [6]. In the KB assay the medium supplement lactalbumin hydrolysate at 3 mg/ml reportedly increases the yield of total cell protein without stimulating the rate of growth and increases the sensitivity and reproducibility with streptovitacin A [4]. The use of a positive control whose cytotoxic effect is altered by chemical or physical variations in assay conditions is therefore recommended.
Food allergens
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2020
Confusion can arise in the determination of cow's milk allergy because of the different forms of cow's milk used in challenges, e.g., liquid cow's milk, nonfat dry milk, and infant formula. Similarly, fatal anaphylaxis has resulted from inadvertent or unexpected exposure to different milk proteins in other foods (e.g., casein in sausage). Reliable analytical results for milk allergens (casein, lactalbumin, and lactoglobulin) in nondairy foods are needed for them to be causally associated with milk allergy. Wal's review [19] on the biochemistry and immunochemistry of milk proteins indicates that no single allergen or structure accounts for milk allergenicity or predicts an allergic response. The great variability in the polysensitization and IgE responses to cow's milk and potential immunologic cross-reactions to milk of other species, such as buffalo, goat, sheep, and camel, will vary according to the characteristics of the population studied. Any food that contains native or denatured milk proteins or fragments derived thereof may trigger an allergic reaction.
The efficacy of myo-inositol supplementation to reduce the incidence of gestational diabetes: a meta-analysis
Published in Gynecological Endocrinology, 2022
Myo-inositol, one stereoisomer of inositol, is the most common one [13,38]. It leads to the production of phosphoinositides which have an insulin-like effect on metabolic enzymes in glucose metabolism [39–42]. The efficacy of myo-inositol to prevent gestational diabetes is through improving glucose homeostasis as an insulin sensitizer substance [43–45]. In addition, the α-lactalbumin addition promotes intestinal absorption and bioavailability of myo-inositol [42]. Regarding the sensitivity analysis, significant heterogeneity was found for the incidence of gestational diabetes, and may be caused by several factors. Firstly, the doses of myo-inositol were different among the included RCTs, ranging from 1100 mg to 4000 mg daily. The dose of myo-inositol supplementation was recommended to be 2000 mg myo-inositol twice a day [14,18,25]. Secondly, pregnant women with have different baseline characteristics such as glucose and lipid metabolism, which may affect the efficacy assessment of myo-inositol. Thirdly, myo-inositol is combined with various agents such as D-Chiro inositol, and more studies are needed to find the ideal combination methods of inositol supplementation.
An innovative approach to polycystic ovary syndrome
Published in Journal of Obstetrics and Gynaecology, 2022
Mariano Bizzarri, Patrizia Logoteta, Giovanni Monastra, Antonio Simone Laganà
MI human plasma concentration has a mean value of 32.5 ± 1.5 μM/L, with a range of 26.8–43.0 μM/L, according to Leung et al. (Leung et al. 2011). Monastra et al. (Monastra et al. 2018b) administered 6 g MI in a single oral administration to 18 healthy volunteers (men and women). They found that baseline levels in the study subjects were 32.17 ± 4.76 μM/L, using gas chromatography-mass spectrometry for this detection. After MI administration, its average peak plasma concentration (at 180 min) increased about threefold with respect to baseline, reaching 95.06 ± 7.31 μM/L. Of note, this MI dose was chosen to get a good detection of this molecule, however this dosage is not very different from that normally given to patients, i.e. 4 g per day per os for at least 3 months. In the study by Montanino et al. (Montanino Oliva et al. 2018), where the authors used gas chromatography-mass spectrometry, the basal MI value found in PCOS patients was less than in normal women, i.e. 17 ± 3.5 μmol/L, in agreement with Unfer’s hypothesis that MI deficiency is a common feature in PCOS patients. After a treatment with 2 g MI plus 50 mg alpha-lactalbumin, twice a day by oral route for three months, this concentration raised by 106%, reaching 35 ± 3.8 μmol/L.
Kumiss Supplementation Reduces Oxidative Stress and Activates Sirtuin Deacetylases by Regulating Antioxidant System
Published in Nutrition and Cancer, 2020
Kumiss, a traditional drink of the nomadic peoples of Central Asia, is a light-alcohol fermented mare's milk drink obtained by its own natural microbiota content (a mixture of lactic acid bacteria and yeasts). Kumiss is made by adding preformed fermented milk into the fresh mare milk. Approximately 50% of mare's milk protein is casein and the other half includes lactate and lactoglobulin. The high ratio of lactoglobulin and lactalbumin in total protein gives the milk an easily digestible, liquid quality, and high nutritional value. Compared to cow, goat, and sheep milk, mare milk has a higher proportion of water and lactose while having lower ratio of dry matter, protein, fat, and mineral content. Additionally, high-molecular weight unsaturated fatty acids which is rich in high physiological values, including linoic, linolenic, and arachidonic acid are found in abundance (1). Previous studies have reported that kumiss has beneficial effects on endocrine glands, digestive, immune, urinary, circulatory, and nervous systems as well as an antibiotic effect against a large number of bacteria (2).