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PubMed1998

Interaction of microorganisms, epithelium, and lymphoid cells of the mucosa-associated lymphoid tissue.

Differentiation of specific epithelial cell lineages during development, as well as epithelial plasticity in response to heterologous cell-to-cell cross talk during adult life, accounts for the large variety of functions which are performed by the mucosal surfaces found in the human body. Among its functions, the digestive mucosa is able to sample antigens and microorganisms through M cells of Peyer's patches' follicle-associated epithelium, in order to trigger the development of either tolerance or immune responses. At least in the gut, M-cell formation is immunoregulated. Close contact between immune cells and intestinal epithelium modifies the permeability of the epithelial barrier by inducing the conversion of enterocytes into M cells, offering at the same time an opportunistic way of invasion for pathogens. These lympho-epithelial interactions triggering M-cell formation have now been modeled in culture.

Adult↗
PubMed1995

PFK activity in muscle and heart tissue is differentially affected by dietary restriction.

This research examined the effect of dietary restriction on PFK activity (one of the enzymes in the glycolytic pathway) in selected skeletal and heart muscle tissue. Fifty-five Sprague-Dawley female rats were separated into three different groups for 10 weeks of dietary restriction: AL = ad lib fed, MR = weight reduced to 81% of AL and SR = weight reduced to 63% of AL. Gastrocnemius white (GW), plantaris, soleus (S) and heart (H) muscle tissue were dissected out and assayed for PFK activity. PFK activity (mumole/g/min) in GW was 105 +/- 7, 86 +/- 6 and 61 +/- 6 for AL, MR & SR, respectively (AL > MR > SR, P < 0.05). PFK activity in S was 25 +/- 2, 22 +/- 1 and 16 +/- 1 for AL, MR and SR, respectively (AL, MR > SR, P < 0.05). In contrast, PFK activity in H was unaffected (P > 0.05). These data suggest that PFK activity in various muscle tissues is differentially affected during diet-induced weight loss.

Animals↗
PubMed1990

Simple non-invasive early detection and localization of specific cancer tissues of internal organs and differentiation of cancer tissue from surrounding areas infected by cancer related viruses, as well as evaluation of their micro-circulatory condition & drug uptake using the BI-Digital O-Ring Test.

In 1984, the author first developed a simple, quick, non-invasive, economical method of detecting cancer in specific internal organs, using the Bi-Digital O-Ring Test (BDORT), with a microscope slide of specific cancer of a specific internal organ as a reference control substance. The detection rate for cancer screening was much greater than with any standard diagnostic tests. When imaging was performed using the BDORT, the area of positive response to the cancer positive slide was often much greater than the actual size of the cancer itself. This was due to the fact that most of the cancer tissue of the lungs or digestive system contained viruses such as HTLV-3 (often found in adenocarcinoma of the lung, stomach, head of pancreas, and colon) or HTLV-1 (often found in small-cell carcinoma of the lung and certain types of leukemia). The extent of the virus positive area was often far greater than that of the cancer tissue itself and was distributed in a much greater area surrounding the cancer. For this reason, the virus alone showed a response which could be mistaken for cancer tissue. The author succeeded in differentiating the exact location of cancer tissue itself from surrounding cancer related virus (with or without other microbes) positive area by using a pair of identical microscope slides with the same cancer tissue. One of the slides was exposed to ultra-violet rays (peak wavelength of 253.7 nm mercury vapor atomic resonance spectral line) for 40 seconds-4 minutes. After this exposure, the BDORT response to the virus (with or without other microbes) associated with the cancer tissue was completely eliminated, while the response to the cancer tissue was maintained. Using an ultraviolet exposed cancer slide, the imaging of the part of the body which responded to this virus-free cancer slide indicated the actual location of the cancer tissue, which was often confirmed by standard X-ray or other imaging methods when the thickness of the tumor was relatively large. These cancers detectable by standard laboratory tests had strikingly weakening response to the BDORT (-3.5 and -4), with ultra-violet exposed cancer slide as well as for antibody of Oncogen C-fos. The smallest size of cancer tissue detected by this method was less than 1mm in diameter in the very early stage of the cancer, which usually cannot be detected by current laboratory tests.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1986

Theoretical and experimental analysis of scatter from inhomogeneous slabs in a 60Co beam: the differential tissue-air ratio method (DTAR).

A theoretical and experimental analysis of scatter from inhomogeneous slabs in a 60Co beam has been developed. This analysis has been used to examine the differential scatter-air ratio method (DSAR). It has been found that a simplification of this method gives more accurate results than the original one. Thus, a method which takes advantage of this simplification has been developed, called the 'differential tissue-air ratio method (DTAR)'. It is compared with experimental results. The accuracy is satisfactory for a wide range of applications (usually approaching the limits of the precision of the measurements, about 2%) and leads to calculation times not significantly longer than any conventional method (e.g. Batho).

Air↗
PubMed1984

Development of thyroid hormone dependence for growth in the rat: a study involving transplanted fetal, neonatal, and juvenile tissues.

The role of thyroid hormones (TH) in the growth of rat tissue of different ages was investigated in a transplant system. Paws from 14- to 15-day-old fetal rats or pieces of xiphoid cartilage from 18- to 20-day fetuses and 2-, 9-, or 30-day-old rats were transplanted under the kidney capsule of control or thyroidectomized (TX) syngeneic adult female hosts and grown there for 11 days. Paw transplants grew equally well, and tissue differentiation was similar in control and TX hosts. The degree of ossification was measured by a histometric procedure and was found to be equivalent in paws that developed in situ until 4 days postpartum and in paw transplants of equivalent age grown for 11 days on the kidneys of euthyroid or TX hosts. These results show that growth and differentiation of the skeletal and other tissues of the paw are not dependent on TH during the transplant period, which encompassed the equivalent of the late fetal and first few days of neonatal life. Transplanted xiphoid cartilage was used to analyze growth and the development of TH dependence of a differentiated tissue which is relatively uniform in animals of different ages. In control and TX hosts, the growth capacity of transplanted xiphoids declined progressively with increasing donor age. The tissue also showed an age-related increase in dependence on TH for growth. The xiphoid transplants from the fetal rats grew equally well in the euthyroid and hypothyroid hosts, but those from 30-day-old rats showed a near-total dependence on TH for growth. Overall, the results indicate that rat supportive tissues begin to develop a dependence on TH for growth during the second week postpartum.

Animals↗
PubMed2006

Simulation of cell differentiation in fracture healing: mechanically loaded composite scaffolds in a novel bioreactor system.

Cell differentiation during bone healing following a fracture is influenced by various biological and mechanical factors. We introduce a method for the examination of cell and tissue differentiation simulating a fracture gap in vitro. A closed bioreactor system allows the imitation of the biological, mechanical, and biochemical conditions in vitro. The initial hematoma formed in a fracture is simulated with a mixed construct composed of lyophilized cancellous bone and a fibrin matrix in a sandwich configuration. The construct may be loaded with osteoprogenitor cells. Exemplarily, constructs were loaded with rabbit periosteal cells and cultivated under mechanical loading with 7 kPa at 0.05 Hz for up to two weeks. During the observation period, cell morphology and correlating protein synthesis changed under mechanical stimulation. Cell differentiation differed between the various regions of the constructs. The periosteal cells were arranged perpendicularly to the mechanical loading and differentiated to osteoblastic forms with rising collagen type I synthesis, constant alkaline phosphatase activity, and initiation of the calcification of the extracellular matrix. The observed pattern of cell and tissue differentiation was similar to the one seen in the early phase of bone healing. In conclusion, the presented method allows simulation of cell and tissue differentiation during the early phase of fracture healing. It could serve as an in vitro model for the examination of mechanical and pharmacological influences during the early phase of bone healing on a cellular level.

Animals↗
PubMed2002

Tissue transglutaminase differentially modulates apoptosis in a stimuli-dependent manner.

Tissue transglutaminase is a unique member of the transglutaminase family as it not only catalyzes a transamidating reaction, but also binds and hydrolyzes GTP and ATP. Tissue transglutaminase has been reported to be pro-apoptotic, however, conclusive evidence is still lacking. To elucidate the role of tissue transglutaminase in the apoptotic process human neuroblastoma SH-SY5Y cells were stably transfected with vector only (SH/pcDNA), wild-type tissue transglutaminase (SH/tTG) and tissue transglutaminase that has no transamidating activity but retains its other functions (SH/C277S). In these studies three different apoptotic stimuli were used osmotic stress, staurosporine treatment and heat shock to delineate the role of tissue transglutaminase as a transamidating enzyme in the apoptotic process. In SH/tTG cells, osmotic stress and staurosporine treatments resulted in significantly greater caspase-3 activation and apoptotic nuclear changes then in SH/pcDNA or SH/C277S cells. This potentiation of apoptosis in SH/tTG cells was concomitant with a significant increase in the in situ transamidating activity of tissue transglutaminase. However, in the heat shock paradigm, which did not result in any increase in the transamidating activity in SH/tTG cells, there was a significant attenuation of caspase-3 activity, LDH release and apoptotic chromatin condensation in SH/tTG and SH/C277S cells compared with SH/pcDNA cells. These findings indicate for the first time that the effect of tissue transglutaminase on the apoptotic process is highly dependent on the type of the stimuli and how the transamidating activity of the enzyme is affected. Tissue transglutaminase facilitates apoptosis in response to stressors that result in an increase in the transamidating activity of the enzyme. However, when the stressors do not result in an increase in the transamidating activity of tissue transglutaminase, than tissue transglutaminase can ameliorate the apoptotic response through a mechanism that is independent of its transamidating function. Further, neither the phosphatidylinositol-3-kinase pathway nor the extracellular-regulated kinase pathway is downstream of the modulatory effects of wild-type tissue transglutaminase or C277S-tissue transglutaminase in the apoptotic cascade.

Amino Acid Substitution↗
PubMed2003

Identification of tissue-specific genes in nasopharyngeal epithelial tissue and differentially expressed genes in nasopharyngeal carcinoma by suppression subtractive hybridization and cDNA microarray.

Suppression subtractive hybridization (SSH) was performed for isolation of tissue-specific genes in nasopharyngeal epithelial tissue, by use of cDNAs from human adult nasopharyngeal epithelial tissue as tester and mixed cDNAs from esophagus, lung, liver, heart, stomach, spleen, skeletal muscle, kidney, and skin as drivers. Fourteen differentially expressed genes in nasopharyngeal epithelial tissue were obtained. Among these genes, LPLUNC1 and SPLUNC1 were confirmed to be specifically expressed in nasopharyngeal epithelial tissue and the trachea. A novel transcript of SPLUNC1, which we designate NASG, was found. We also combined SSH and cDNA microarray hybridization to identify genes whose expressions were altered in nasopharyngeal carcinoma (NPC). We used NPC cell line HNE1 and primary human embryo nasopharyngeal epithelial cells in one SSH experiment, and NPC biopsies and normal adult nasopharyngeal epithelial tissue in another. Some 1,200 SSH inserts from four subtractive cDNA libraries were arrayed onto nylon membranes by use of robotic printing. Differential gene expression was verified by hybridizing of the membranes with radioactively labeled first-strand cDNA from NPC cell line HNE1, primary human embryo nasopharyngeal epithelial cells, NPC biopsies, and normal adult nasopharyngeal epithelial tissue. Seventeen differentially expressed genes in NPC were obtained. Among these genes, we identified SPLUNC1 and LPLUNC1 to be down-expressed in NPC biopsies (34/48, 33/48).

Adult↗
PubMed1979

Effects of glucocorticoids on differentiation of zona glomerulosa of fetal adrenal cortex of rats.

The tissue differentiation of the zona glomerulosa of the fetal adrenal cortex of rats was studied by giving experimental treatments to the fetus in vivo. A low-glucocorticoid-condition was given to the fetus by bilateral adrenalectomy of pregnant rats for removing exogenous glucocorticoids from the fetus, and by brain aspiration of the fetuses for removing the fetal pituitary gland (ACTH) and endogenous glucocorticoids. When the fetus was placed under a low-glucocorticoid-condition for the last couple of days of gestation, poor differentiation of the zona glomerulosa occurred specifically in the fetal adrenal cortex. The degree of the poor differentiation seemed to be proportional to the duration of the low-glucocorticoid-condition. Supplemental administration of glucocorticoids could prevent this poor differentiation of the zona glomerulosa. These results indicate that the tissue differentiation of the zona glomerulosa of the fetal adrenal cortex depends much on glucocorticoids.

Adrenal Cortex↗
PubMed2001

HOXA10 expression is repressed by progesterone in the myometrium: differential tissue-specific regulation of HOX gene expression in the reproductive tract.

HOX genes are essential regulators of development in all multicellular organisms, including humans. We have previously shown that HOXA10 is expressed in the developing uterus and later in the adult human endometrium. HOX genes regulate endometrial development in response to sex steroids. Here, we demonstrate that HOXA10 is expressed in the myometrium as well. In situ hybridization reveals abundant HOXA10 expression, and Northern analysis demonstrates differential HOX gene expression in the myometrium throughout the menstrual cycle. HOXA10 expression decreases in the midsecretory phase, coinciding with high serum progesterone levels. Treatment of primary myometrial cell cultures with progesterone decreases HOXA10 expression in vitro-paralleling the expression seen in vivo. Despite the presence of progesterone receptors in the endometrium and myometrium, HOXA10 is differentially regulated in each tissue by progesterone. HOXA10 expression is induced in the stroma and decreased in the myometrium by progesterone. The differential tissue-specific response of this gene in response to progesterone is likely mediated by sex steroid receptor coactivators or corepressors. Decreased myometrial expression of developmental regulatory genes such as HOXA10 in the nonpregnant uterus may dedifferentiate the myometrium and allow growth in preparation for pregnancy.

Blotting, Northern↗
PubMed2004

Skeletal tissue growth, differentiation and mineralization in the NASA rotating wall vessel.

The NASA Rotating Wall Vessel (RWV) is a device that creates a unique environment that supports three-dimensional tissue growth, a heightened level of cell differentiation and randomizes the position of the downward gravitational force on cells. Embryonic bone formation encompasses a cascade of chondrogenic and osteogenic events, which can be altered by changes in gravitational loading. These studies were conducted to determine if the chondrogenic cascade in bone formation would be enhanced or hindered in the unique culture environment of the RWV. Embryonic mouse pre-bone tissues were placed in the RWV at one of four different stages of chondrogenesis, ranging from undifferentiated mesenchyme cells to chondrocytes on the verge of undergoing terminal chondrocyte differentiation. After culture, tissues were analyzed for their size, the amount of alkaline phosphatase (ALP) activity and their ability to form a mineralized matrix. Tissue consisting of cells at the early phase of chondrogenesis grew very little and did not differentiate or mineralize when cultured in the RWV. Some tissues were cultured for short periods in the RWV then cultured in standard culture dishes (SCD). Following this culture regime, the cartilage grew only a small amount, but alkaline phosphatase activity increased, and some mineralized regions formed. The pattern of mineralization was abnormal, with two mineralized zones at each end of the cartilage instead of a single central zone. Tissues that were at the three more advanced stages of chondrogenesis when placed in the RWV showed substantial growth, differentiation and mineralization. Mineralization patterns in these older tissues was normal. Tissues at the oldest stage of chondrogenesis showed more growth and as much or more mineralization as tissue cultured only in SCD. These data suggest that exposure to the RWV at early stages of chondrogenesis severely limits the ability for cartilage growth and yields abnormal downstream morphogenesis. However, at later stages of chondrogenesis, the RWV environment may be beneficial and enhance growth and development. Future studies to characterize intercellular signaling molecules and gene expression activities of chondrocytes in the RWV will be valuable for understanding the mechanism of skeletogenesis.

Animals↗
PubMed2004

Differential tissue-specific regulation of antiviral CD8+ T-cell immune responses during chronic viral infection.

The hallmarks of the immune response to viral infections are the expansion of antigen-specific CD8(+) cytotoxic T lymphocytes (CTLs) after they encounter antigen-presenting cells in the lymphoid tissues and their subsequent redistribution to nonlymphoid tissues to deal with the pathogen. Control mechanisms exist within CTL activation pathways to prevent inappropriate CTL responses against disseminating infections with a broad distribution of pathogen in host tissues. This is demonstrated during overwhelming infection with the noncytolytic murine lymphocytic choriomeningitis virus, in which clonal exhaustion (anergy and/or deletion) of CTLs prevents immune-mediated pathology but allows persistence of the virus. The mechanism by which the immune system determines whether or not to mount a full response to such infections is unknown. Here we present data showing that the initial encounter of specific CTLs with infected cells in lymphoid tissues is critical for this decision. Whether the course of the viral infection is acute or persistent for life primarily depends on the degree and kinetics of CTL exhaustion in infected lymphoid tissues. Virus-driven CTL expansion in lymphoid tissues resulted in the migration of large quantities of CTLs to nonlymphoid tissues, where they persisted at stable levels. Surprisingly, although virus-specific CTLs were rapidly clonally exhausted in lymphoid tissues under conditions of chronic infection, a substantial number of them migrated to nonlymphoid tissues, where they retained an effector phenotype for a long time. However, these cells were unable to control the infection and progressively lost their antiviral capacities (cytotoxicity and cytokine secretion) in a hierarchical manner before their eventual physical elimination. These results illustrate the differential tissue-specific regulation of antiviral T-cell responses during chronic infections and may help us to understand the dynamic relationship between antigen and T-cell populations in many persistent infections in humans.

Acute Disease↗
PubMed1990

Analysis of the role of basic fibroblast growth factor in growth and differentiation of transplanted fetal rat paws and intestines.

Paws and intestinal segments from 16-day-old rat fetuses were transplanted bilaterally under the kidney capsule of adult female hosts and grown there for different periods of time. The direct effects of an antiserum to bovine basic fibroblast growth factor (bFGF) and of recombinant bFGF on growth and tissue differentiation in the transplants were evaluated by infusing them into the right renal artery via a catheter attached to an osmotic minipump. Infusion of the antiserum into the right kidney of intact hosts for 6 or 10 days did not affect either growth of the paws or bone differentiation in them. By contrast, the anti-FGF serum significantly inhibited the growth of intestinal transplants and caused slight retardation of villus differentiation. We presume that this inhibition resulted from neutralization of the bFGF produced within the transplants, as infusion of nonimmune rabbit serum had no such effects on the intestinal segments. In hypophysectomized hosts growth of both types of transplants was greatly reduced, and tissue differentiation was retarded, presumably reflecting low serum insulin-like growth factor-I levels. Infusion of the recombinant bFGF (5 micrograms/rat.day) into the hypophysectomized hosts stimulated growth of the paws and promoted ossification of the phalanges, but not the carpals. Intestinal growth was not affected by bFGF, and villus development was not restored. These results indicate that fetal rat structures are differentially dependent on and responsive to bFGF for growth and differentiation. These findings, when considered in relation to our previous results with transplanted 10-day-old rat embryos, indicate that growth and tissue differentiation during the embryonic period of rat development are more dependent on bFGF than are these processes in the fetal period.

Animals↗
PubMed1975

Cell proliferation and cell differentiation in tissue cultures of adult muco-cilliary epithelia.

Explants and monolayers from a variety of muco-ciliary epithelia were cultivated in vitro and the kinetics of their proliferation and differentiation described. New epithelial lining and epithelial-like monolayer sheets of cells formed in which the migration cells were all originally undifferentiated cycling stem cells. The divided and differentiated in ML growth into cell types characteristic of the tissue source: however, the control mechanisms which regulate cell division and cell differentiation in the tissues were lost outside the tissue framework. Cell division and cyto-differentiation in ML growths both in ciliated and in mucus-producing cells, were not always mutually exclusive.

Animals↗
PubMed2000

Immunohistochemical and ultrastructural localization of leptin and leptin receptor in human white adipose tissue and differentiating human adipose cells in primary culture.

Leptin is mainly produced in white adipose tissue and acts both at distant sites and locally at the tissue from which it originates. The cellular and subcellular localization of leptin and its receptor (Ob-receptor [Ob-R]) and their relationship to various stages of fat cell maturation have not been characterized as yet. Therefore, we analyzed leptin and Ob-R by using reverse transcriptase-polymerase chain reaction, immunohistochemistry, and ultrastructural immunogold labeling in human white adipose tissue and in human adipocyte cell cultures at early and late stages of differentiation. Both leptin and its receptor were present in mature unilocular fat cells. The thin cytoplasmic rim of the adipocytes exhibited the strongest expression of both leptin and Ob-R. At early stages of differentiating human adipocytes, leptin was mainly expressed in multilocular preadipocytes, whereas the Ob-R was found predominantly on fibroblast-like cells. Other cellular components of human white adipose tissue were characterized by anti-CD31 for endothelial cells, anti-CD68 for macrophages, and antibodies specifically labeling B-cells and T-cells. In addition to fat cells, endothelial cells were immunopositive for the full-length leptin receptor. On the ultrastructural level, leptin was mainly found attached to cellular membranes and in small alveolate vesicle-like structures in the cytoplasm of adipocytes. Leptin was also present on the cell membranes of endothelial cells and macrophages. We conclude that the expression of the Ob-R in human white adipose tissue is not restricted to adipocytes but is present in resident endothelial and immune cells. Ultrastructural localization studies revealed an association of leptin with cell membranes and small vesicles. The cellular and subcellular distribution of leptin and its receptor suggests an important autocrine and paracrine role for leptin in human adipose tissue.

Adipose Tissue↗
PubMed1993

Morphological aspects of chromaffin tissue: the differential fixation of adrenaline and noradrenaline.

The morphological aspects of chromaffin tissue are reviewed, based mainly on our studies on the mouse adrenal gland. Particular attention was focused on the differential fixation of adrenaline and noradrenaline, and on the uptake and storage of [3H]dopa, [3H]dopamine and related substances in the adrenaline-storing (A) and noradrenaline-storing (NA) cells. Scanning electron microscopy combined with the NaOH-maceration method was useful for demonstrating the 3-dimensional organisation of nerve terminals, chromaffin cells, glial elements and vascular elements. In transmission electron microscopy, 3 types of chromaffin cell were distinguished. They were A, NA and SGC (small granule chromaffin) cells. After glutaraldehyde fixation followed by postosmication, A cell granules showed lower electron density, whereas NA cell granules were solid and dark. This difference in appearance between A and NA cells was first explained by the hypothesis that, after glutaraldehyde fixation, most of the adrenaline dissolved, whereas noradrenaline was precipitated in situ. Later, this hypothesis was supported by a series of autoradiographic and radioisotopic assay studies using [3H]dopa, [3H]dopamine and related substances; when [3H]adrenaline occurred, radioactivity in A cells mostly disappeared in the specimen, whereas that in the NA cells remained. At 15-60 min after an i.p. injection of [3H]dopa or [3H]dopamine, the concentration of radioactivity in A cells was higher than that in NA cells. However, in hypophysectomised mice, the radioactivity was low and evenly distributed in these 2 types of chromaffin cell. It was deduced that the carrier activities for extracellular dopa and dopamine were made greater in the A cells than in the NA cells by the pituitary gland. The hypophysectomy effects were restored by i.p. administration of ACTH.

Adrenal Medulla↗