Changes in the mitotic activity and number of pathological mitoses in the epidermis of the mouse's ear in the initial period of carcinogenesis

1966 ◽  
Vol 62 (4) ◽  
pp. 1166-1168
Author(s):  
A. P. Vasil'eva
Keyword(s):  
Mitotic Activity ◽  
Initial Period ◽  
Pathological Mitoses

The reproductive system and embryonic diapause in the female kangaroo, Marcopodus giganteus

1967 ◽  
Vol 15 (3) ◽  
pp. 441 ◽  
Author(s):  
MJ Clark ◽  
WE Poole
Keyword(s):  
Corpus Luteum ◽  
Mitotic Activity ◽  
Reproductive System ◽  
Luteal Phase ◽  
Post Partum ◽  
Ovarian Follicle ◽  
Initial Period ◽  
Secretory Cells ◽  
Ovarian Activity ◽  
Embryonic Diapause

The reproductive system of the female grey kangaroo consists as in other marsupiais, of two ovaries, two uteri, two lateral vaginae, and a median vaginal canal. The changes which occur during the oestrous cycle or pregnancy can be divided into three phases: (1) a proliferative phase characterized by maturation and rupture of an ovarian follicle and its subsequent transformation into a new corpus luteum, and by cell division in the uteri; (2) a luteal phase, when the corpus luteum is fully formed and the luteal cells attain their maximum size, and the uterine gland cells are tall columnar, with basally situated nuclei; and (3) a post-luteal phase when the secretory cells of the corpus luteum and uteri degenerate. Repair begins in the uteri before the end of pregnancy and this is supplemented by post-partum mitotic activity, but post-partum oestrus does not occur. The uterine glands are small, and ovarian activity is inhibited during the initial period of lactation. A small proportion of females with pouch young over 100 days old return to oestrus and mate. Mitotic activity then ceases in the uteri, in the newly formed corpus luteum, and the blastocyst until the pouch young is lost or approaches the end of pouch life, when mitotic activity is resumed in the corpus luteum and blastocyst. The occurrence of embryonic diapause has been confirmed in both wild and captive animals.

Desensitisation of rat thyroid to the growth-stimulating action of TSH during prolonged goitrogen administration Persistence of refractoriness following withdrawal of stimulation

1982 ◽  
Vol 101 (4) ◽  
pp. 562-569 ◽  
Author(s):  
D. Wynford-Thomas ◽  
B. M. J. Stringer ◽  
E. D. Williams
Keyword(s):  
Mitotic Activity ◽  
Initial Period ◽  
Fold Increase ◽  
Cell Number ◽  
Follicular Cell ◽  
Follicular Cells ◽  
Functional Responses ◽  
Rat Thyroid ◽  
Serum Tsh

Abstract. We have previously shown that administration of goitrogen to the rat leads to a sustained elevation of serum TSH but to only a short-lived burst of mitotic activity in the thyroid, growth eventually ceasing after a few months. This work investigates the possibility that this progressive desensitisation may result simply from continued exposure to high levels of TSH and examines the effect of a period of interruption of goitrogen treatment on the sensitivity of the gland to subsequent TSH stimulation. Rats were treated with the goitrogen aminotriazole (ATA) for an initial period of 80 days to reach the plateau of thyroid growth. ATA was then withdrawn for 25 days and subsequently re-introduced for a further 35 days. Animals were killed in groups of 8 at frequent intervals and the following measurements carried out: — Serum TSH, T3 and T4, thyroid weight, follicular cell number and mitotic activity. The initial period of ATA treatment led to a 5-fold increase in serum TSH, a 10-fold increase in thyroid weight and a 9-fold increase in follicular cell number. Mitotic activity stabilised at a few times control levels. Following withdrawal of ATA, TSH and mitotic activity fell to below normal. Thyroid weight fell by 66% but there was no significant fall in follicular cell number. Re-introduction of ATA simply led to a return of all variables to their previous 'stimulated' levels. There was no second burst of mitotic activity and no renewed thyroid growth. The results show that the desensitisation of follicular cells to the growth-stimulating action of TSH following prolonged stimulation is not reversed by withdrawal of the stimulus, and is therefore unlikely to be mediated by a 'downregulation' at receptor or post-receptor level of the type observed for functional responses in vitro. Other possible mechanisms are discussed.

An adrenocortical oncocytoma with unusual mitochondrial inclusions and cytoplasmic crystals

1994 ◽  
Vol 52 ◽  
pp. 250-251
Author(s):  
W.T. Gunning ◽  
G.D. Haselhuhn ◽  
E.R. Phillips ◽  
S.H. Selman
Keyword(s):  
Adrenal Gland ◽  
Salivary Glands ◽  
Mitotic Activity ◽  
Diagnostic Criteria ◽  
Vascular Invasion ◽  
Benign Neoplasm ◽  
Benign Tumors ◽  
Nuclear Morphology ◽  
Case Presentation ◽  
Microscopic Evidence

Within the last few years, adrenal cortical tumors with features concordant with the diagnostic criteria attributed to oncocytomas have been reported. To date, only nine reported cases exist in the literature. This report is the tenth case presentation of a presumptively benign neoplasm of the adrenal gland with a rare differentiation. Oncocytomas are well recognized benign tumors of the thyroid, parathyroid, and salivary glands and of the kidney. Other organs also give rise to these types of tumors, however with less frequency than the former sites. The characteristics generally used to classify a tumor as an oncocytoma include the following criteria: the tumor is 1) usually a solitary circumscribed mass with no gross nor microscopic evidence of metastasis (no tissue nor vascular invasion), 2) fairly bland in terms of mitotic activity and nuclear morphology, and 3) composed of large eosinophillic cells in which the cytoplasm is packed full of mitochondria (Figure 1).

SEJARAH KONFLIK KEBANGKITAN ISLAM DI MINANGKABAU: Sebuah Tinjauan Awal Terhadap Proses Kemunculannya

2018 ◽  
pp. 33-48
Author(s):  
Ihsan Sanusi
Keyword(s):  
Human Life ◽  
Initial Period ◽  
Analysis Model ◽  
Islamic Revival ◽  
Religious Texts ◽  
Interactive Analysis ◽  
The Past ◽  
The Reformation ◽  
History Of ◽  
Correct Understanding

This article in principle wants to examine the history of the emergence of the conflict of Islamic revival in Minangkabau starting from the Paderi Movement to the Youth in Minangkabau. Especially in the initial period, namely the Padri movement, there was a tragedy of violence (radicalism) that accompanied it. This study becomes important, because after all the reformation of Islam began to be realized by reforming human life in the world. Both in terms of thought with the effort to restore the correct understanding of religion as it should, from the side of the practice of religion, namely by reforming deviant practices and adapted to the instructions of the religious texts (al-Qur'an and sunnah), and also from the side of strengthening power religion. In this case the research will be directed to the efforts of renewal by the Padri to the Youth towards the Islamic community in Minangkabau. To discuss this problem used historical research methods. Through this method, it is tested and analyzed critically the records and relics of the past. In analyzing the data in this research basically used approach or interactive analysis model by Miles and Huberman. In this analysis model, the three components of the analysis are data reduction, data presentation, and conclusion drawing or verification, the activity is carried out in an interactive form with the process of collecting data as a process that continues, repeats, and continues to form acycle.

SOME RESULTS OF MOISTURE AND SALT TRANSFER IN THE INITIAL PERIOD OF PLANT DEVELOPMENT

2020 ◽  
Vol Special issue (1) ◽  
pp. 68-74
Author(s):  
Aliakbar Khojiev ◽  
◽  
Rustam Murodov
Keyword(s):  
Plant Development ◽  
Initial Period

ACHIEVEMENT OF SINGAPORE'S INDEPENDENCE AND DIFFICULTIES ON THE INITIAL PERIOD OF DEVELOPMENT

2019 ◽  
Vol 17 (2) ◽  
pp. 75-84
Author(s):  
Ilyas Shakirov ◽  
Keyword(s):  
Initial Period ◽  
Historical Sources ◽  
History Of ◽  
The Given

In the article considered events between 1945-1965 years in Singapore. On the ground of historical sources author of the given article learned the history of gaining independence by Singapore, as well, difficulties country carried out over 20 years

Mitotic Activity Dynamics in Recalcitrant Seeds Acer sachharinum during Maturation and Germination

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 479c-479
Author(s):  
L. Kozeko ◽  
V. Troyan ◽  
L. Musatenko
Keyword(s):  
Cell Division ◽  
Mitotic Activity ◽  
Quiescent State ◽  
Activity Levels ◽  
Recalcitrant Seeds ◽  
Mature Embryos ◽  
Before And After ◽  
Orthodox Seeds ◽  
Mature Seeds ◽  
Activity Dynamics

In orthodox seeds the cell division within the embryo meristems arrests during maturation at embryo moisture content (MC) 65% to 47%, and the maturation completion and transition of seeds to quiescent state occurs at MC about 10%. The arrest of cycling happens asynchronously in different meristematic tissues during desiccation: first in shoot and then in root. The aim of this work was to define a mitotic activity dynamics in recalcitrant seeds with the high MC at maturation end and the absence of quiescent state characteristic of it. The object was seeds of Acer saccharinum, using widely for planting of greenery in Kiev city. The mitotic activity was determined in 0.5 mm of the embryo root pole (RP) and 0.5 mm of the shoot pole with embryo leaves (SP). The A. sachharinum seeds completed them maturation at MC 53% (FW basis). During maturation the mitotic index (MI) in RP decreased from 3.2% in immature seeds (at embryos MC 80%) to 0 in mature seeds and in SP–from 5.4% to 3.3%, respectively. Cell division in SP arrested by dehydration of mature embryos to MC 46% by PEG 6000 (30%). The seeds lost viability by desiccation to MC 34%. The mature seeds were able to germinate immediately after abscission. During seed germination the cell division reactived in RP and increased in SP already before root protrusion. In plantlets 10–15 mm long the MI increased to 8% in RP and 12% in SP. Thus, the strategy of immediate germination of recalcitrant A. sachharinum seeds includes a preservation of cell division in SP of mature embryos, in contrast with orthodox seeds, and high mitotic activity levels in meristems of germinating embryos before and after root protrusion.

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