Immunohistochemical analysis of NaPi2b protein (MX35 antigen) expression and subcellular localization in human normal and cancer tissues.

AIM: To study the expression profile of the NaPi2b protein and its localization in breast, ovarian and lung cancer cells in relation to normal tissues adjacent to tumor. METHODS: Immunohistochemical analysis with monoclonal antibody MX35 was applied for investigation of NaPi2b protein expression in breast, lung and ovarian carcinomas. Intensity of NaPi2b protein expression was calculated with semiquantitative scores. RESULTS: NaPi2b (MX35) protein expression was detected in breast, lung and ovarian cancer cells and adjacent normal tissue. We have shown that in contrast to ovarian tumors in breast and lung tumors NaPi2b expression is down regulated comparing to correspondent normal tissues. CONCLUSION: This study provides the data on the pattern of NaPi2b expression and cellular localization in breast, lung and ovarian cancers, which might be useful for understanding the mechanism of transport and maintenance of inorganic phosphate in cancer and normal cells, as well as for developing novel immunotherapeutic approaches based on MX35 monoclonal antibody.

The influence of maternal hypothyroidism and radioactive iodine on rat embryonal development: thyroid C-cells.

There have been no works devoted to the study of the influence of (131)I and maternal (131)I-induced hypothyroidism on the state of the C-cells in the thyroid gland of the developing embryos. A study was made on the effect of a dose of 150 microCi (131)I (0.5 Gy) leading to hypothyroidism in rats, on 35 mother rats and 168 newborn pups. The mother rats were divided into control and four treated groups which were injected with (131)I before pregnancy, on gestation days 5, 10, and 16, respectively. Immunohistochemically, the thyroid gland was examined for calcitonin-positive cells. Maternal hypothyroidism induced by (131)I leads to the development of hyperplasia and hyperthrophy of calcitonin-positive cells in the pups at the time of birth. The discovery of separate C-cells in the peripheral zone of the thyroid lobe may be evidence of an unbalance in the development of the medial and lateral source of the thyroid. There is a verifiable increase in the quantity of C-cells per 1 mm(2) field of the localization in the central zone of the gestation days 10 and 16 groups. This might be a compensatory mechanism for regulating the activity of the thyroid gland under induced hypothyroidism. Thus, in cases when there is a breakdown in the normal external regulation of the embryonic morphogenesis, a reduction in the level of maternal thyroid hormones and also direct exposure to (131)I, there is also a change in the foetus' internal regulatory systems. A change in C-cell system could lead to the appearance of endocrinological disorders later in life.

[Proliferating cell nuclear antigen of the rat thyroid gland before and after birth]. / Iadernyi antigen kletochnoi proliferatsii shchitovidnoi zhelezy krys do i posle rozdeniia.

We were studied the proliferative activity of the thyroid gland's cells of embryo and adult Wistar rats due to using the antiserum against the cell nuclear antigen (PCNA). The 100% of cells in thyroid's embryo was a positive on the 16th, 17th, 18th stages of the embryonic development (stages by Kornegy). The percent of PCNA-positive cells considerably increased to 67% on the 19th stage. This fact the 20th and 21th stages of prenatal development relatively the previous stage coordinate with starting of the thyroid hormones in fetal thyroid gland and the first follicles formation. The small increasing of number of PCNA-positive cells detected on the 20th and 21th stages of prenatal development relatively the previous stage. Considerable elevation of the proliferating cells to 75% immediately before the birth (22th stage). An infant rats had have the 39% of proliferating cells. The 51% cells divided on the 5th day of postnatal development. Considerable decreased of the cell's division was occurred until the postnatal day 60. Using of the PCNA antiserum allowed to study cell proliferation in thyroid gland during pre- and postnatal rat development.

Immunohistochemical study of fibronectin and thyroglobulin in the thyroid gland of female rats after exposure to radioactive iodine.

The aim of this work was to study the effect of a dose of 150 microCi 131I on the barrier properties of the thyroid epithelium in pregnant female rats. Thirty-five female Wistar rats were divided into a control and four experimental groups (each distinguished by the time of 131I injection: group I--no less then 12 days before mating; groups II, III, and IV--on 5th, 10th, and 16th days of gestation, respectively). The thyroid glands were fixed in Bouin's fluid, embedded in paraffin, and stained immunohistochemically for thyroglobulin and fibronectin. In group IV the appearance of follicles with fibronectin-positive colloid demonstrates the penetration of blood plasma into the follicular lumen. There are more fibronectin positive follicles in group III. Regardless of the nature of the follicles' contents, numerous thyrocytes with an intensive fibronectin positive reaction begin to appear in the follicles. In group II the number of fibronectin positive follicles and thyrocytes is clearly reduced, and in group I only a few remain. In group IV there is a noticeable reduction in the quantity of colloid inside the follicles and often an absence of any thyroglobulin positive reaction. There are thyrocytes in which thyroglobulin positive granules localized in the basal zone. There is thyroglobulin positive staining in the stroma and blood vessels. In group II thyroglobulin is no longer found in the stroma. Small doses of 131I provoke a serious breakdown in the thyroid epithelium's barrier properties, although these changes are of a transient nature. The central zone of the thyroid gland reacts more actively and dynamically to exposure to radioactive iodine than the peripheral zone.

Some morphological changes in the rat thyroid gland during experimental hyperphenylalaninemia.

BACKGROUND: Little is known about the effect of phenylketonuria on the thyroid gland. In the present study, this problem was investigated by using a defined experimental model of hyperphenylalaninemia (HPA). METHODS: The experimental group was subjected to an HPA regimen (Matsuo and Hommes, 1988. Neurochem. Res., 13:867-870) from the 5th day of postnatal development. The pups were decapitated on the 7th, 14th, 21st, 28th, and 35th days. The thyroid glands were fixed in Bouin's fluid and routinely embedded in paraffin. The staining techniques used were Mallory-Slinchenko's method, toluidin blue, silver impregnation of the basement membrane, immunohistochemical staining of the proliferating cell nuclear antigen (PCNA), and neuron-specific enolase (NSE). RESULTS: The size of the follicles was less than that in the control group. There were no substantial changes in the epitheliomer structures. In almost all of the treated groups, a reduction in the number of PCNA+, NSE+, and mast cells was observed until the 28th day. On the 28th day of HPA, the level of mast cell degranulation was higher (61%) than that in the control group. On the 35th day, these parameters began to reach normal levels. From the 28th day, degenerative changes in the thyroid glands of treated animals were observed in the NSE+ cells. CONCLUSIONS: The HPA condition mainly has an influence on the number and structure of the NSE+ cells of the thyroid gland. One may assume that under HPA the increase in mast cell degranulation plays a significant role in the normalisation of the parameter of the thyroid gland.

Histological studies of atrazine toxicity on the thyroid gland in rats.

Little is known about the toxic activity of the atrazine (a herbicide, commonly used in agricultural production) on the thyroid gland. In this study the compound was administered orally in female albino rats at sublethal exposure equivalent to 0.2 LD50 doses for 6 and 12 days. At termination of dosing the anesthetized animals were killed and blood was drawn for the determination of serum triiodothyronine (T3) and thyroxin (T4). A dose-dependent decrease of serum T3 concentration was observed in all the groups (control: 0.57 nmol-L-1; 6 days: 0.35 nmol-L-1; 12 days: 0.21 nmol-L-1). The thyroid gland was examined light-microscopically. Bouin's solution-fixed thyroids were embedded in paraffin and sections cut at 6 microns, stained separately with toluidine blue according to Slinchenko's method. Histologically in experimental groups epithelium featured small cuboidal cells and occasional structures of the follicles confluence within epitheliomers. A dose-dependent changes of the following parameters were observed: (a) increasing of number of follicle-building thyroid cells; (b) increasing of follicular volume; (c) decreasing of nucleus volume. Investigation of the whole population of thyroid mast cells disclosed no change in degranulation intensity. By contrast, degranulation intensity was decreased in perifollicular mast cells from groups treated with atrazine in dose-dependent manner. There are no changes observed in degranulation of stromal mast cells. These results suggesting that differences in response to the atrazine might account for an aspect of the functional heterogeneity within the rat thyroid mast cell population.

The epitheliomeral concept of the thyroid gland's structural organization.

BACKGROUND: The permanent increase in the number of cases of different forms of thyroid pathology requires a deeper study of the thyroid structure and its morphogenetic processes. METHODS: The thyroid glands of Wistar rats were used in a composite study that involved standard light microscopy, semithin sections, silver staining, immunohistochemistry, morphometry, three-dimensional analysis, and computer-assisted three-dimensional reconstruction. RESULTS: The absolute majority of follicles have from one to seven interfollicular contacts (C) with other neighbouring follicles. The surface of C makes up 32% of the follicular basal surface. In the central zone of 1-micron-thick sections, the relative quantity of C per follicle (0.44 +/- 0.05) is 36% more than in the peripheral zone (0.28 +/- 0.07; P < 0.05). The analysis of serial sections shows that 134 follicles have 133 C. Only three follicles are separate; four form pair groups, and others form groups that include up to 92 follicles. Follicles form linear chains with numerous branches. A three-dimensional reconstruction demonstrates a spatial configuration of the parenchyma's elements. In C, the basement membrane is absent. Consequently, a group of interconnected follicles form a parenchymal compartment with a common basement membrane. We named these parenchymal compartments "epitheliomers." Both the formation of new follicles and follicular fusion take place within the boundaries of the epitheliomer without violating the integrity of the compartment. The fusion of follicles is brought on by the destruction of the epithelium of C. CONCLUSIONS: The authors put forward a new "epitheliomeral" concept with regard to the structural organization of the thyroid gland.