Fine Structural Evaluation of Parathyroid Glands From Cows Fed Low and High Calcium Diets

1973 ◽  
Vol 31 ◽  
pp. 678-679
Author(s):  
C. C. Capen ◽  
H. E. Black ◽  
C. D. Arnaud
Keyword(s):  
Dairy Cows ◽  
Parathyroid Glands ◽  
Endocrine Function ◽  
Chief Cells ◽  
Structural Evaluation ◽  
High Calcium ◽  
Ultrastructure And Function ◽  
And Function ◽  
Jersey Cows

The calcium (CA) content of the prepartal diet has been shown to significantly influence the development of profound hypocalcemia with paresis in dairy cows near parturition. The mechanisms by which these provocative and preventative diets influence endocrine function and skeletal metabolism are uncertain. The objective of this investigation was to evaluate the effects of feeding high and low CA diets on the ultrastructure and function of parathyroid chief cells in adult cows.The effects of feeding a low CA diet (4.9 gm/day for 30 days) was investigated in 3 non-1actating Jersey cows. The serum CA decreased from 10.7 to 8.8 mg/100 ml after 30 days.

Fine Structural and Biochemical Investigations on the Effects of High Calcium Prepartal Diets on Homeostatic Mechanisms in Thyroid Glands, Bone, and Intestine Of Cows

1973 ◽  
Vol 31 ◽  
pp. 352-353
Author(s):  
H. E. Black ◽  
C. C. Capen ◽  
J. T. Yarrington ◽  
G. N. Rowland
Keyword(s):  
Goblet Cells ◽  
C Cells ◽  
Long Term Effects ◽  
High Calcium ◽  
Thyroid Glands ◽  
Ultrastructure And Function ◽  
And Function ◽  
Circulating Levels ◽  
Homeostatic Mechanisms

Parturient paresis of dairy cows is a metabolic disease characterized by the development of severe hypocalcemia and hypophosphatemia near parturition in the presence of high circulating levels of parathyroid hormone. High calcium (CA) diets have been incriminated in increasing the incidence of the disease. The objective of this investigation was to determine the long-term effects of feeding a high CA (150 gm CA and 25 gm P/day) prepartal diet on the ultrastructure and function of thyroid parafollicular (C-) cells and duodenal absorptive and goblet cells of pregnant cows, and to correlate these findings with microradiographic evaluation of bone.

scholarly journals Alterations in flight muscle ultrastructure and function in Drosophila tropomyosin mutants.

1996 ◽  
Vol 135 (3) ◽  
pp. 673-687 ◽  
Author(s):  
A J Kreuz ◽  
A Simcox ◽  
D Maughan
Keyword(s):  
Amino Acid ◽  
Power Output ◽  
Flight Muscle ◽  
Structure And Function ◽  
Wild Type ◽  
Muscle Tropomyosin ◽  
Ultrastructure And Function ◽  
And Function ◽  
Net Power Output ◽  
Current Report

Drosophila indirect flight muscle (IFM) contains two different types of tropomyosin: a standard 284-amino acid muscle tropomyosin, Ifm-TmI, encoded by the TmI gene, and two > 400 amino acid tropomyosins, TnH-33 and TnH-34, encoded by TmII. The two IFM-specific TnH isoforms are unique tropomyosins with a COOH-terminal extension of approximately 200 residues which is hydrophobic and rich in prolines. Previous analysis of a hypomorphic TmI mutant, Ifm(3)3, demonstrated that Ifm-TmI is necessary for proper myofibrillar assembly, but no null TmI mutant or TmII mutant which affects the TnH isoforms have been reported. In the current report, we show that four flightless mutants (Warmke et al., 1989) are alleles of TmI, and characterize a deficiency which deletes both TmI and TmII. We find that haploidy of TmI causes myofibrillar disruptions and flightless behavior, but that haploidy of TmII causes neither. Single fiber mechanics demonstrates that power output is much lower in the TmI haploid line (32% of wild-type) than in the TmII haploid line (73% of wild-type). In myofibers nearly depleted of Ifm-TmI, net power output is virtually abolished (< 1% of wild-type) despite the presence of an organized fibrillar core (approximately 20% of wild-type). The results suggest Ifm-TmI (the standard tropomyosin) plays a key role in fiber structure, power production, and flight, with reduced Ifm-TmI expression producing corresponding changes of IFM structure and function. In contrast, reduced expression of the TnH isoforms has an unexpectedly mild effect on IFM structure and function.

Essential thrombocythemia in a child: Platelet ultrastructure and function

1980 ◽  
Vol 8 (1) ◽  
pp. 87-107 ◽  
Author(s):  
Marion I. Barnhart ◽  
Tae H. Kim ◽  
Bruce L. Evatt ◽  
Abdelsalam H. Ragab ◽  
Victor K. Lui ◽  
...  
Keyword(s):  
Essential Thrombocythemia ◽  
Ultrastructure And Function ◽  
And Function

scholarly journals Ultrastructure and function of mitochondria in gametocytic stage ofPlasmodium falciparum

Parasite ◽  
2000 ◽  
Vol 7 (1) ◽  
pp. 19-26 ◽  
Author(s):  
J. Krungkrai ◽  
P. Prapunwattana ◽  
S.R. Krungkrai
Keyword(s):  
Ofplasmodium Falciparum ◽  
Ultrastructure And Function ◽  
And Function

scholarly journals Evidence of Regeneration of Testicular and Epididymal Tissue Structure and Function Following Withdrawal from Sub-chronic Khat Exposure: Studies in the Rabbit Animal Model

2020 ◽  
pp. 10-23
Author(s):  
Albert W. Nyongesaa ◽  
Esther M. Malukib ◽  
Jemimah A. Simbaunib
Keyword(s):  
Body Weight ◽  
Chronic Exposure ◽  
Structure And Function ◽  
The Body ◽  
Endocrine Function ◽  
Eastern Africa ◽  
Blood Samples ◽  
Middle East Countries ◽  
Group I ◽  
And Function

Khat, Catha edulis, use is rampant in Eastern Africa and Middle East countries with associated reports of reproductive function impairment in the body of the user. Reports on recovery post long-term khat exposure are obscure. The present study investigated evidence of restoration of testicular and epididymal structure and function during withdrawal from cytotoxic damage caused by sub-chronic exposure of khat extract. Twenty-eight male rabbits were divided into 7 groups of 4 rabbits each. Group I (control) was administered normal saline while groups II, III and IV were administered 1.0 g/kg, 10 g/kg and 20 g/kg body weight of khat extract, respectively, via oral gavage on alternate days of the week for 12 weeks. Blood samples from animals were collected for hormonal assays followed by euthanasia using 26.4 mg/kg body weight of Sagatal sodium intramuscularly for testicular and epididymal histology. Group V, VI and VII were administered 1.0 g/kg, 10 g/kg and 20 g/kg body weight of khat extract, respectively, orally on alternate days of the week for 12 weeks followed by 1-month withdrawal period, blood samples collected for hormone assays and animals sacrificed for testicular and epididymal histology. High khat dose, 20 g/kg body weight, at sub-chronic exposure caused degeneration in spermatogenic cells with accompanying decrease in plasma FSH and testosterone. Histological output of Sertoli cells, Leydig cells and epididymal epithelium appeared unaffected in treatment groups. Post withdrawal data showed apparent regeneration of seminiferous epithelium and restoration of plasma FSH and testosterone comparable to control. It appears khat extract preferentially affected germ cell spermatogonia and subsequent daughter cells while stem cell spermatogonia were unaffected and contributed to regeneration of germinal epithelium and endocrine function.

scholarly journals Altered Glut-2 accumulation and β-cell function in mice lacking the exocrine-specific transcription factor, Mist1

2005 ◽  
Vol 187 (3) ◽  
pp. 407-418 ◽  
Author(s):  
E N Fazio ◽  
M Everest ◽  
R Colman ◽  
R Wang ◽  
C L Pin
Keyword(s):  
Transcription Factor ◽  
Glucose Tolerance ◽  
Cell Function ◽  
Regulatory Gene ◽  
Immunohistochemical Analysis ◽  
Endocrine Function ◽  
Pancreatic Acinar Cells ◽  
Protein Accumulation ◽  
Specific Transcription Factor ◽  
And Function

Mist1 is an exocrine-specific transcription factor that is necessary for the establishment of cell organization and function of pancreatic acinar cells. While Mist1 is not expressed in the endocrine pancreas, the disorganized phenotype of the exocrine component may affect endocrine function. Therefore, we examined endocrine tissue morphology and function in Mist1-knockout (Mist1KO) mice. Endocrine function was evaluated using a glucose-tolerance test on 2–10-month-old female mice and revealed a significant reduction in glucose-clearing ability in 10-month-old Mist1KO mice compared with wild-type mice. Immunohistochemical analysis of islet hormone expression indicated that the decreased endocrine function was not due to a decrease in insulin-, glucagon- or somatostatin-expressing cells. However, a decrease in the size of islets in 10-month-old Mist1KO mice was observed along with a decrease in Glut-2 protein accumulation. These results suggest that the islets in Mist1KO mice are functionally compromised, likely accounting for the decreased glucose tolerance. Based on these findings, we have identified that the loss of a regulatory gene in the exocrine compartment can affect the endocrine component, providing a possible link between susceptibility for various pancreatic diseases.

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