Mechanisms and hormonal regulation of shell formation

2022 ◽  
pp. 813-859
Author(s):  
Yves Nys ◽  
Joel Gautron ◽  
Alejandro B. Rodriguez-Navarro ◽  
Maxwell Hincke
Keyword(s):  
Hormonal Regulation ◽  
Shell Formation

The Effect of Exogenous Fluoride on the Calcium PUMP, Ciliary Activity, and Shell Formation of the Fingernail Clam, Musculium Transversum

1982 ◽  
Vol 40 ◽  
pp. 58-59
Author(s):  
Anthony Paparo ◽  
Judy A. Murphy ◽  
Robert Dean
Keyword(s):  
Mississippi River ◽  
Calcium Pump ◽  
Bottom Fauna ◽  
Ciliary Activity ◽  
Shell Formation ◽  
Middle Reach ◽  
Shell Matrix ◽  
Fingernail Clams ◽  
Ca Carbonate

In the mid-1950's, fingernail clams virtually disappeared from a 100-mile section of the IL River, a tributary of the Mississippi River, due to unknown causes. A survey of the bottom fauna of the IL River in 1979, revealed that the clams were still absent from the middle reach of the River, where they had been abundant prior to the die-off in the 1950's. Some factor(s) in the River currently prevent the clams from recolonizing areas where they were formerly abundant. Recently, clams exposed to fluoride developed abnormal grooves in the shell matrix. Fluorides are known to be protoplasmic poisons removing essential body calcium by precipitation. Since the shell consists primarily of Ca carbonate, this investigation examines the possible role of fluoride on shell formation and the poisoning of the Ca pump which can directly inhibit lateral ciliary activity on the gill.

Silicon Substitution for Calcium in the Shell of the Fingernail Clam, Musculium Transversum Studied By X-Ray Analysis

1980 ◽  
Vol 38 ◽  
pp. 560-561
Author(s):  
Judith A. Murphy ◽  
Anthony Paparo ◽  
Richard Sparks
Keyword(s):  
Carbonic Anhydrase ◽  
River Water ◽  
Food Chains ◽  
Well Water ◽  
Shell Formation ◽  
X Ray ◽  
Molluscan Shell ◽  
Fingernail Clams

Fingernail clams (Muscu1ium transversum) are dominant bottom-dwelling animals in some waters of the midwest U.S. These organisms are key links in food chains leading from nutrients in water and mud to fish and ducks which are utilized by man. In the mid-1950’s, fingernail clams disappeared from a 100-mile section of the Illinois R., a tributary of the Mississippi R. Some factor(s) in the river and/or sediment currently prevent clams from recolonizing areas where they were formerly abundant. Recently, clams developed shell deformities and died without reproducing. The greatest mortality and highest incidence of shell deformities appeared in test chambers containing the highest proportion of river water to well water. The molluscan shell consists of CaCO3, and the tissue concerned in its secretion is the mantle. The source of the carbonate is probably from metabolic CO2 and the maintenance of ionized Ca concentration in the mantle is controlled by carbonic anhydrase. The Ca is stored in extracellular concentric spherical granules(0.6-5.5μm) which represent a large amount of inertCa in the mantle. The purpose of this investigation was to examine the role of raw river water and well water on shell formation in the fingernail clam.

GENE ACTIVATION IN MAMMARY CELLS

1972 ◽  
Vol 71 (2_Suppla) ◽  
pp. S346-S368 ◽  
Author(s):  
Roger W. Turkington ◽  
Nobuyuki Kadohama
Keyword(s):  
Cell Differentiation ◽  
Gene Transcription ◽  
Hormonal Regulation ◽  
Gene Activation ◽  
Milk Proteins ◽  
Mouse Mammary Gland ◽  
Nuclear Proteins ◽  
Mammary Cells ◽  
Alveolar Cells ◽  
Mammary Cell

ABSTRACT Hormonal activation of gene transcription has been studied in a model system, the mouse mammary gland in organ culture. Transcriptive activity is stimulated in mammary stem cells by insulin, and in mammary alveolar cells by prolactin and insulin. Studies on the template requirement for expression of the genes for milk proteins demonstrate that DNA methylation has an obligatory dependence upon DNA synthesis, but is otherwise independent from hormonal regulation of mammary cell differentiation. Incorporation of 5-bromo-2′deoxyuridine into DNA selectively inhibits expression of the genes for specific milk proteins. Undifferentiated mammary cells activate the synthesis of specific acidic nuclear proteins when stimulated by insulin. Several of these induced acidic nuclear proteins are undetectable in unstimulated undifferentiated cells, but appear to be characteristic components of the nuclei of differentiated cells. These results indicate that mammary cell differentiation is associated with a change in acidic nuclear proteins, and they provide evidence to support the concept that acidic nuclear proteins may be involved in the regulation of gene transcription and of mammary cell differentiation.

Modern approaches to the prevention and treatment of alterations in reproductive health in women with somatoform disorders and autonomic homeostasis

2016 ◽  
pp. 98-101
Author(s):  
Vl.V. Podolsky ◽  
◽  
V.V. Podolsky ◽  
Keyword(s):  
Reproductive Health ◽  
Hormonal Regulation ◽  
Preventive Measures ◽  
Somatoform Disorders ◽  
Emotional Health ◽  
Uterine Fibroids ◽  
Reproductive Function ◽  
Epidemiological Studies ◽  
Prevention And Treatment ◽  
Artificial Abortion

The objective: the developing of a system of preventive measures and principles of pregravid preparation for women with somatoform disorders and violation of autonomic homeostasis (VAH), in which observed changes in reproductive health (CRH) in the shape of states after undergoing artificial abortion, infertility and uterine fibroids. Patients and methods. Conducted clinical and epidemiological studies in the population of women of fertile age (WFA) allowed identifying for further examination of women with CRH in the form of state after undergoing artificial abortion, infertility and uterine fibroids in women with VAH. Further women were examined, in particular the conducted clinical and instrumental methods of research; determined the state of autonomic homeostasis and psycho emotional health of the biotopes of the organism, immunity; analyzed the hormonal regulation of the menstrual cycle; performed genetic studies and determined the morphofunctional state of reproductive system. Results. The most frequent complications during pregnancy in women who had CRH in history in the form of abortions, infertility and uterine fibroids and in the background of the PAF, there was a threat of interruption of pregnancy (often in I and II trimester – 56%) and preterm delivery (21%). The study of the catamnesis of further reproductive health found that in the case of well-conducted therapeutic measures in women undergoing artificial abortion, had infertility and uterine leiomyoma in the background of VAH, restore reproductive function, and in 82% of cases occurred a pregnancy. Conclusion. The the provided study of reproductive health, and state of various organs and systems of fertile aged women with somatoform disorders and violations of the autonomic homeostasis allowed to develop preventive measures for these women and pregravid preparation with the inclusion to the therapy Magnesium and vitamins (Magne-В6®). Key words: somatoform disorders, violation of autonomic homeostasis, changes in reproductive health, prevention and treatment, women of fertile age, Magne-В6®.

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