Atomikerroskasvatuksen soveltaminen kemiantekniikassa

Tässä kirjallisuustyössä tutkittiin atomikerroskasvatuksen (ALD) soveltamista kemiantekniikassa. Työn alussa kerrottiin atomikerroskasvatuksesta, sen toimintaperiaatteista ja prosessitekniikasta. Tämän jälkeen tutkittiin viittä eri kemiantekniikan sovellusta, jotka olivat polymeerien pinnoittaminen, heterogeenisten katalyyttien syntetisointi, membraanien modifiointi, korroosionesto ja kaasunilmaisimet. ALD on ohutkalvotekniikka, jolla voidaan valmistaa nanometrin tai jopa Ångströmin (1 Å = 0.1 nm) tarkkuudella epäorgaanisia materiaalikerroksia, jotka yleensä ovat metallioksideja, kuten alumiinioksidi. ALD perustuu kaasu-kiintoainereaktioihin, joissa kaasumaiset kemialliset prekursorit reagoivat vuorotellen kasvualustan kanssa. Tyypilliset prekursorit ovat metalliligandi ja vesi, joka on yleisin hapen lähde ALD-reaktioissa. ALD−reaktiot suoritetaan yleensä matalassa paineessa (100−200 Pa) ja korkeassa lämpötilassa (200–400 °C) suljetussa reaktorikammiossa. ALD-prosesseissa voidaan hyödyntää myös plasmaa alentamaan reaktiolämpötiloja. Plasman avulla prekursoreista luodaan hyvin reaktiivisia radikaaleja, jotka voivat reagoida jopa huoneenlämmössä. Lämpöherkkiä polymeerejä voidaan pinnoittaa ohutkalvoilla, joilla voidaan lisätä esimerkiksi pakkausmateriaalien suojaa happea ja vesihöyryä vastaan. ALD:llä voidaan syntetisoida tarkasti nanomittakaavan heterogeenisiä katalyyttejä, joilla on korkea dispersio tukimateriaalin pinnalla. ALD:n avulla voidaan säästää katalyyttimateriaalia menettämättä katalyytin aktiivisuutta, mikä on tärkeää monien katalyyttisovellusten taloudellisuuden kannalta, esimerkiksi polttokennot. ALD soveltuu hyvin membraanien modifiointiin, koska kaasumaiset prekursorit leviävät tasaisesti membraanin huokosiin. Membraanien pinnoittamisella pyritään vaikuttamaan, selektiivisyyteen, hydrofiilisyyteen, liuotinkestävyyteen, huokoskokoon ja sen jakaumaan. Lisäksi membraaneja voidaan pinnoittaa katalyyttisillä ohutkalvoilla, mikä on tärkeää nanoreaktoreiden kehityksen kannalta. ALD:llä voidaan pinnoittaa esimerkiksi terästä, ja vähentää täten teräksen korroosiota. Puolijohtavia metallioksideja voidaan käyttää kaasunilmaisimina, joiden valmistuksessa ALD:n tarkkuudesta on suurta hyötyä.

Cognitive Development of Very Low Birth Weight Children from Infancy to Pre-school Age

The survival of preterm born infants has increased but the prevalence of long-term morbidities has still remained high. Preterm born children are at an increased risk for various developmental impairments including both severe neurological deficits as well as deficits in cognitive development. According to the literature the developmental outcome perspective differs between countries, centers, and eras. Definitions of preterm infant vary between studies, and the follow-up has been carried out with diverse methods making the comparison less reliable. It is essential to offer parents upto-date information about the outcome of preterm infants born in the same area. A centralized follow-up of children at risk makes it possible to monitor the consequences of changes in the treatment practices of hospitals on developmental outcome. This thesis is part of a larger regional, prospective multidisciplinary follow-up project entitled “Development and Functioning of Very Low Birth Weight Infants from Infancy to School Age” (PIeniPAinoisten RIskilasten käyttäytyminen ja toimintakyky imeväisiästä kouluikään, PIPARI). The thesis consists of four original studies that present data of very low birth weight (VLBW) infants born between 2001 and 2006, who are followed up from the neonatal period until the age of five years. The main outcome measure was cognitive development and secondary outcomes were significant neurological deficits (cerebral palsy, CP, deafness, and blindness). In Study I, the early crying and fussing behavior of preterm infants was studied using parental diaries, and the relation of crying behavior and cognitive and motor development at the age of two years was assessed. In Study II, the developmental outcome (cognitive, CP, deafness, and blindness) at the age of two years was studied in relation to demographic, antenatal, neonatal, and brain imaging data. Development was studied in relationship to a full-term born control group born in the same hospital. In Study III, the stability of cognitive development was studied in VLBW and full-term groups by comparing the outcomes at the ages of two and five years. Finally, in Study IV the precursors of reading skills (phonological processing, rapid automatized naming, and letter knowledge) were assessed for VLBW and full-term children at the age of five years. Pre-reading skills were studied in relation to demographic, antenatal, neonatal, and brain imaging data. The main findings of the thesis were that VLBW infants who fussed or cried more in the infancy were not at greater risk for problems in their cognitive development. However, crying was associated with poorer motor development. The developmental outcome of the present population was better that has been reported earlier and this improvement covered also cognitive development. However, the difference to fullterm born peers was still significant. Major brain pathology and intestinal perforation were independent significant risk factors for adverse outcome, also when several individual risk factors were controlled for. Cognitive development at the age of two years was strongly related with development at the age of five years, stressing the importance of the early assessment, and the possibility for early interventions. Finally, VLBW children had poorer pre-reading skills compared with their full-term born peers, but the IQ was an important mediator even when children with mental retardation were excluded from the analysis. The findings suggest that counseling parents about the developmental perspectives of their preterm infant should be based on data covering the same birth hospital. Neonatal brain imaging data and neonatal morbidity are important predictors for developmental outcome. The findings of the present study stress the importance of both short-term (two years) and long-term (five years) follow-ups for the individual, and for improving the quality of care.

Bone Health, Osteoporosis and Fracture Risk in Neurofibromatosis 1 - An Emphasis on Osteoclasts

Neurofibromatosis 1 (NF1) is an autosomal dominant hereditary syndrome, affecting skin, neural tissues and skeleton. Hallmarks of NF1 include benign cutaneous neurofibroma tumors, pigmentation lesions on the skin and in the iris, learning disabilities and predisposition to selected malignancies. Low bone mineral density (BMD) and osteopenia/osteoporosis are common in NF1. Osteoporosis is a systemic disorder characterized by low bone mineral density and increased fracture risk. Treatment of osteoporosis aims to prevent falls and decrease fracture risk. Osteoporosis is diagnosed in adults by measuring BMD and evaluating clinical risk factors of the patient. Bone turnover is a process of old bone resorbed by osteoclasts and new bone formed by osteoblasts. Multinuclear osteoclasts are derived from osteoclast progenitors, which can be isolated from peripheral blood. Osteoclast progenitors were isolated from 17 NF1 patients and healthy controls, and cultured in vitro to osteoclasts. NF1 osteoclasts are hyperactive, displaying increased differentiation and resorption capacity, abnormal morphology and tolerance to serum deprivation compared to control osteoclasts. These findings expanded the study to evaluate the effects of bisphosphonates, drugs designed to treat osteoporosis, in osteoclasts derived from blood samples of 20 NF1 and control persons. The number of control osteoclasts was expectedly reduced after bisphosphonate treatment. However, NF1 osteoclasts tolerated the apoptotic effect of alendronate, zoledronic acid and clodronate in vitro compared to controls. NF1-related osteoporosis was found in ~20 % of the patients, and selected laboratory parameters were measured. Patients with NF1 have increased levels of serum CTX and PINP, reflecting increased bone turnover in vivo. BMD decreases progressively in NF1 as evaluated in 19 NF1 patients 12 years after their initial BMD measurement. Patients with NF1-related osteopenia often progress to osteoporosis. This was found in patients aged 37-76.

MicroRNAs as novel regulators of skeletal homeostasis

The human skeleton is composed of bone and cartilage. The differentiation of bone and cartilage cells from their bone marrow progenitors is regulated by an intrinsic network of intracellular and extracellular signaling molecules. In addition, cells coordinate their differentiation and function through reciprocal cell‐to‐cell interactions. MicroRNAs (miRNAs) are small, single‐stranded RNA molecules that inhibit protein translation by binding to messenger RNAs (mRNAs). Recent evidence demonstrates the involvement of miRNAs in multiple biological processes. However, their role in skeletal development and bone remodeling is still poorly understood. The aim of this thesis was to elucidate miRNA‐mediated gene regulation in bone and cartilage cells, namely in osteoblasts, osteoclasts, chondrocytes and bone marrow adipocytes. Comparison of miRNA expression during osteogenic and chondrogenic differentiation of bone marrow‐derived mesenchymal stem cells (MSCs) revealed several miRNAs with substantial difference between bone and cartilage cells. These miRNAs were predicted to target genes essentially involved in MSC differentiation. Three miRNAs, miR‐96, miR‐124 and miR‐199a, showed marked upregulation upon osteogenic, chondrogenic or adipogenic differentiation. Based on functional studies, these miRNAs regulate gene expression in MSCs and may thereby play a role in the commitment and/or differentiation of MSCs. Characterization of miRNA expression during osteoclastogenesis of mouse bone marrow cells revealed a unique expression pattern for several miRNAs. Potential targets of the differentially expressed miRNAs included many molecules essentially involved in osteoclast differentiation. These results provide novel insights into the expression and function of miRNAs during the differentiation of bone and cartilage cells. This information may be useful for the development of novel stem cell‐based treatments for skeletal defects and diseases.

Thymic atrophy in cattle poisoned with Solanum glaucophyllum

Solanum glaucophyllum (Sg) [= S. malacoxylon] is a calcinogenic plant inducing "Enzootic Calcinosis" in cattle. The 1,25-dihydroxyvitamin D3, its main toxic principle, regulates bone and calcium metabolism and also exerts immunomodulatory effects. Thymocyte precursors from bone marrow-derived progenitor cells differentiate into mature T-cells. Differentiation of most T lymphocytes is characterized not only by the variable expression of CD4/CD8 receptor molecules and increased surface density of the T cell antigen receptor, but also by changes in the glycosylation pattern of cell surface glycolipids or glycoproteins. Thymocytes exert a feedback influence on thymic non-lymphoid cells. Sg-induced modifications on cattle thymus T-lymphocytes and on non-lymphoid cells were analysed. Heifers were divided into 5 groups (control, intoxicated with Sg during 15, 30 or 60 days, and probably recovered group). Histochemical, immunohistochemical, lectinhistochemical and morphometric techniques were used to characterize different cell populations of the experimental heifers. Sg-poisoned heifers showed a progressive cortical atrophy that was characterized using the peanut agglutinin (PNA) lectin that recognizes immature thymocytes. These animals also increased the amount of non-lymphoid cells per unit area detected with the Picrosirius technique, WGA and DBA lectins, and pancytokeratin and S-100 antibodies. The thymus atrophy found in intoxicated animals resembled that of the physiological aging process. A reversal effect on these changes was observed after suppression of the intoxication. These findings suggest that Sg-intoxication induces either directly, through the 1,25-dihydroxyvitamin D3 itself, or indirectly through the hypercalcemia, the observed alteration of the thymus.

Establishment of a protocol for obtention of neuronal stem cells lineages from the dog olfactory epithelium

A morphological and cell culture study from nasal mucosa of dogs was performed in order to establish a protocol to obtain a cell population committed to neuronal lineage, as a proposal for the treatment of traumatic and degenerative lesions in these animals, so that in the future these results could be applied to the human species. Twelve mongrel dogs of 60-day aged pregnancy were collected from urban pound dogs in São Paulo. Tissue from cribriform ethmoidal lamina of the fetuses was collected at necropsy under sterile conditions around 1h to 2h postmortem by uterine sections and sections from the fetal regions described above. Isolated cells of this tissue were added in DMEM/F-12 medium under standard conditions of incubation (5% CO², >37ºC). Cell culture based on isolated cells from biopsies of the olfactory epithelium showed rapid growth when cultured for 24 hours, showing phase-bright sphere cells found floating around the fragments, attached on culture flasks. After 20 days, a specific type of cells, predominantly ellipsoids or fusiform cells was characterized in vitro. The indirect immunofluorescence examination showed cells expressing markers of neuronal precursors (GFAP, neurofilament, oligodendrocyte, and III â-tubulin). The cell proliferation index showed Ki67 immunostaining with a trend to label cell groups throughout the apical region, while PCNA immunostaining label predominantly cell groups lying above the basal lamina. The transmission electron microscopy from the olfactory epithelium of dogs revealed cells with electron-dense cytoplasm and preserving the same distribution as those of positive cell staining for PCNA. Metabolic activity was confirmed by presence of euchromatin in the greatest part of cells. All these aspects give subsidies to support the hypothesis about resident progenitor cells among the basal cells of the olfactory epithelium, committed to renewal of these cell populations, especially neurons.

Ultrastructural characterization of bovine umbilical cord blood cells

The umbilical cord blood (UCB) is an important source of pluripotent stem cells, which motivated researches on ontogeny and transplantation. The morphological characterization of umbilical cord cells is the first step to establish subsequent experiments on these areas. Although some information on humans can be found, no data on UCB is available for bovines. Therefore, this work is the first attempt to conduct an ultrastructural characterization of bovine umbilical cord blood. Blood was collected from the umbilical cord of twenty fetuses by punction of the umbilical vein. Samples were processed for whole leucocytes observation by centrifugation and the buffy coat was collected. Cells were washed and pelleted and prepared according to the standard protocol of the transmission electron microscopy. The presence of cells with morphologic characteristics compatible with the precursors from the erythrocytic, neutrophilic, eosinophilic, basophilic, and lymphocytic lineages was observed. Atypical cells with peculiar morphological features, strongly similar to apoptotic cells, were seen. Bovine neutrophils with three types of cytoplasmic granules were also found in the blood. The ultrastructural characteristics of observed bovine UCB cells where similar to those found in other species, suggesting that bovines could possibly constitute an experimental model for approaches on UCB cells research.

Markers of Bone Turnover In Preclinical Development of Drugs for Skeletal Diseases

Skeletal tissue is constantly remodeled in a process where osteoclasts resorb old bone and osteoblasts form new bone. Balance in bone remodeling is related to age, gender and genetic factors, but also many skeletal diseases, such as osteoporosis and cancer-induced bone metastasis, cause imbalance in bone turnover and lead to decreased bone mass and increased fracture risk. Biochemical markers of bone turnover are surrogates for bone metabolism and may be used as indicators of the balance between bone resorption and formation. They are released during the remodeling process and can be conveniently and reliably measured from blood or urine by immunoassays. Most commonly used bone formation markers include N-terminal propeptides of type I collagen (PINP) and osteocalcin, whereas tartrate-resistant acid phosphatase isoform 5b (TRACP 5b) and C-terminal cross-linked telopeptide of type I collagen (CTX) are common resorption markers. Of these, PINP has been, until recently, the only marker not commercially available for preclinical use. To date, widespread use of bone markers is still limited due to their unclear biological significance, variability, and insufficient evidence of their prognostic value to reflect long term changes. In this study, the feasibility of bone markers as predictors of drug efficacy in preclinical osteoporosis models was elucidated. A non-radioactive PINP immunoassay for preclinical use was characterized and validated. The levels of PINP, N-terminal mid-fragment of osteocalcin, TRACP 5b and CTX were studied in preclinical osteoporosis models and the results were compared with the results obtained by traditional analysis methods such as histology, densitometry and microscopy. Changes in all bone markers at early timepoints correlated strongly with the changes observed in bone mass and bone quality parameters at the end of the study. TRACP 5b correlated strongly with the osteoclast number and CTX correlated with the osteoclast activity in both in vitro and in vivo studies. The concept “resorption index” was applied to the relation of CTX/TRACP 5b to describe the mean osteoclast activity. The index showed more substantial changes than either of the markers alone in the preclinical osteoporosis models used in this study. PINP was strongly associated with bone formation whereas osteocalcin was associated with both bone formation and resorption. These results provide novel insight into the feasibility of PINP, osteocalcin, TRACP 5b and CTX as predictors of drug efficacy in preclinical osteoporosis models. The results support clinical findings which indicate that short-term changes of these markers reflect long-term responses in bone mass and quality. Furthermore, this information may be useful when considering cost-efficient and clinically predictive drug screening and development assays for mining new drug candidates for skeletal diseases.

Vesicular Trafficking in Osteoclasts

Osteoclasts are multinucleated bone-degrading cells that undergo large changes in their polarisation and vesicular trafficking during the bone resorption cycle. Rab proteins are small GTPases that offer both temporal and spatial regulation to the transport between membranous organelles. Previously the presence and function of only few of the currently known 60 Rab proteins in osteoclasts have been reported. In this study, the expression of 26 Rab genes in bone-resorbing osteoclasts was demonstrated with gene-specific primer pairs. The further analysis of three Rab genes during human osteoclast differentiation revealed that Rab13 gene is highly induced during osteoclastogenesis. The presence of Rab13 protein in the secretory vesicles directed towards the ruffled border and in the endocytotic or transcytotic pathways in resorbing osteoclasts was excluded. The localisation of Rab13 suggests that that it is associated with a previously unknown vesicle population travelling between the trans-Golgi network and the basolateral membrane in bone resorbing osteoclasts. Rab proteins convey their functions by binding to specific effector proteins. We found a novel Rab13 interaction with endospanins-1 and -2 that are yet poorly characterised small transmembrane proteins. The Rab13 subfamily member Rab8 also bound to endospanins, while Rab10 and unrelated Rabs did not. Rab13 and endospanin-2 co-localised in perinuclear vesicles in transfected cells, demonstrating the interaction also in vivo. The inhibition of Rab13 did not interfere with the localisation of endospanin-2 nor did it affect the cell surface expression of growth hormone receptor, as has been previously described for endospanins. The physiological role of this novel protein-protein interaction thus remains to be clarified. The analysis of the transcytotic route in bone resorbing osteoclasts revealed that multiple vesicle populations arise from the ruffled border and transport the bone degradation products for exocytosis. These vesicles are directed to the functional secretory domain that is encircled by an actin-based molecular barrier. Furthermore, the transcytotic vesicles contain abundant Helix pomatia lectin binding sites and represent lipid raft concentrates. Finally, autophagosomal compartments may also be involved in the transcytosis.

Flavonoids and other phenolic compounds: characterization and interactions with lepidopteran and sawfly larvae

This thesis focuses on flavonoids, a subgroup of phenolic compounds produced by plants, and how they affect the herbivorous larvae of lepidopterans and sawflies. The first part of the literature review examines different techniques to analyze the chemical structures of flavonoids and their concentrations in biological samples. These techniques include, for example, ultraviolet-visible spectroscopy, mass spectrometry, and nuclear magnetic resonance spectroscopy. The second part of the literature review studies how phenolic compounds function in the metabolism of larvae. The harmful oxidation reactions of phenolic compounds in insect guts are also emphasized. In addition to the negative effects, many insect species have evolved the use of phenolic compounds for their own benefit. In the experimental part of the thesis, high concentrations of complex flavonoid oligoglycosides were found in the hemolymph (the circulatory fluid of insects) of birch and pine sawflies. The larvae produced these compounds from simple flavonoid precursors present in the birch leaves and pine needles. Flavonoid glycosides were also found in the cocoon walls of sawflies, which suggested that flavonoids were used in the construction of cocoons. The second part of the experimental work studied the modifications of phenolic compounds in conditions that mimicked the alkaline guts of lepidopteran larvae. It was found that the 24 plant species studied and their individual phenolic compounds had variable capacities to function as oxidative defenses in alkaline conditions. The excrements of lepidopteran and sawfly species were studied to see how different types of phenolics were processed by the larvae. These results suggested that phenolic compounds were oxidized, hydrolyzed, or modified in other ways during their passage through the digestive tract of the larvae.

The myth of nitric oxide in central cardiovascular control by the nucleus tractus solitarii

Considerable evidence suggests that nitroxidergic mechanisms in the nucleus tractus solitarii (NTS) participate in cardiovascular reflex control. Much of that evidence, being based on responses to nitric oxide precursors or inhibitors of nitric oxide synthesis, has been indirect and circumstantial. We sought to directly determine cardiovascular responses to nitric oxide donors microinjected into the NTS and to determine if traditional receptor mechanisms might account for responses to certain of these donors in the central nervous system. Anesthetized adult Sprague Dawley rats that were instrumented for recording arterial pressure and heart rate were used in the physiological studies. Microinjection of nitric oxide itself into the NTS did not produce any cardiovascular responses and injection of sodium nitroprusside elicited minimal depressor responses. The S-nitrosothiols, S-nitrosoglutathione (GSNO), S-nitrosoacetylpenicillamine (SNAP), and S-nitroso-D-cysteine (D-SNC) produced no significant cardiovascular responses while injection of S-nitroso-L-cysteine (L-SNC) elicited brisk, dose-dependent depressor and bradycardic responses. In contrast, injection of glyceryl trinitrate elicited minimal pressor responses without associated changes in heart rate. It is unlikely that the responses to L-SNC were dependent on release of nitric oxide in that 1) the responses were not affected by injection of oxyhemoglobin or an inhibitor of nitric oxide synthesis prior to injection of L-SNC and 2) L- and D-SNC released identical amounts of nitric oxide when exposed to brain tissue homogenates. Although GSNO did not independently affect blood pressure, its injection attenuated responses to subsequent injection of L-SNC. Furthermore, radioligand binding studies suggested that in rat brain synaptosomes there is a saturable binding site for GSNO that is displaced from that site by L-SNC. The studies suggest that S-nitrosocysteine, not nitric oxide, may be an interneuronal messenger for cardiovascular neurons in the NTS

Radioactive fucose as a tool for studying glycoprotein secretion

The efficiency and reliability of radioactive fucose as a specific label for newly synthesized glycoproteins were investigated. Young adult male rabbits were injected intravitreally with [3H]-fucose, [3H]-galactose, [3H]-mannose, N-acetyl-[3H]-glucosamine or N-acetyl-[3H]-mannosamine, and killed 40 h after injection. In another series of experiments rabbits were injected with either [3H]-fucose or several tritiated amino acids and the specific activity of the vitreous proteins was determined. Vitreous samples were also processed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and histological sections of retina, ciliary body and lens (the eye components around the vitreous body) were processed for radioautography. The specific activity (counts per minute per microgram of protein) of the glycoproteins labeled with [3H]-fucose was always much higher than that of the proteins labeled with any of the other monosaccharides or any of the amino acids. There was a good correlation between the specific activity of the proteins labeled by any of the above precursors and the density of the vitreous protein bands detected by fluorography. This was also true for the silver grain density on the radioautographs of the histological sections of retina, ciliary body and lens. The contribution of radioautography (after [3H]-fucose administration) to the elucidation of the biogenesis of lysosomal and membrane glycoproteins and to the determination of the intracellular process of protein secretion was reviewed. Radioactive fucose is the precursor of choice for studying glycoprotein secretion because it is specific, efficient and practical for this purpose

Cell lineage relationship in the stomach of normal and genetically manipulated mice

The oxyntic mucosa of the mouse stomach is lined with a heterogeneous population of cells that form numerous short pits continuous with long tubular glands. Tritiated thymidine radioautography has made it possible to pinpoint the origin of all cell types and to follow the differentiation/migration of different cell lineages along the pit-gland unit. The proliferating multipotent stem cells functionally anchored in the upper glandular region, the isthmus, give rise to three main lineage precursors: 1) pre-pit cells, which migrate upward to the pit while differentiating into mucus-producing pit cells; 2) pre-neck cells, which migrate downward to the glandular neck while differentiating into mucus-producing neck cells that, by approaching the glandular base, gradually change their phenotype into pepsinogen- and intrinsic factor-producing zymogenic cells; 3) pre-parietal cells, which differentiate into acid-producing parietal cells in the isthmus and then undergo bipolar migration towards the pit and the glandular base. Thus, parietal cells are the only cells that complete their differentiation in the isthmus and then migrate to be scattered throughout the pit-gland unit. To determine whether parietal cells play a role in controlling decisions about cell fate within the pit-gland unit, the gastric epithelium has been examined in transgenic mice expressing the H,K-ATPase ß-subunit-1035 to +24/simian virus 40 large T antigen fusion gene. The blockade in parietal cell differentiation in these mice produces an amplification of lineage precursors, a marked depletion of zymogenic cells and an increase in pit cell census. Ablation of parietal cells in another transgenic mouse model expressing the H,K-ATPase ß-subunit-1035 to +24/diphtheria toxin fragment A fusion gene also produces amplification of lineage precursors, and similar effects on zymogenic and pit cell census. These findings strongly suggest that parietal cells produce regulatory signals that control the cellular differentiation program of both pit and zymogenic cell lineages, and would hopefully improve our ability to identify the cellular pathways leading to malignant transformation

Autoradiography reveals regional metabolic differences in the endometrium of pregnant and nonpregnant mice

The rodent endometrium undergoes remarkable modifications during pregnancy, resulting from a redifferentiation of its fibroblasts. During this modification (decidualization), the fibroblasts transform into large, polyhedral cells that establish intercellular junctions. Decidualization proceeds from the subepithelial stroma towards the deep stroma situated next to the myometrium and creates regions composed of cells in different stages of differentiation. We studied by autoradiography whether cells of these different regions have different levels of macromolecular synthesis. Radioactive amino acids or radioactive sulfate were administered to mice during estrus or on different days of pregnancy. The animals were killed 30 min after injection of the precursors and the uteri were processed for light microscope autoradiography. Silver grains were counted over cells of different regions of the endometrium and are reported as the number of silver grains per area. Higher levels of incorporation of amino acids were found in pregnant animals as compared to animals in estrus. In pregnant animals, the region of decidual cells or the region of fibroblasts transforming into decidual cells showed the highest levels of synthesis. Radioactive sulfate incorporation, on the other hand, was generally higher in nonpregnant animals. Animals without decidual cell transformation (nonpregnant and 4th day of pregnancy) showed a differential incorporation by subepithelial and deep stroma fibroblasts. This study shows that regional differences in synthetic activity exist in cells that are in different stages of transformation into decidual cells as well as in different regions of the endometrium of nonpregnant mice

Food, mood and health: a neurobiologic outlook

Hippocrates was the first to suggest the healing power of food; however, it was not until the medieval ages that food was considered a tool to modify temperament and mood, although scientific methods as we know them today were not in use at the time. Modern scientific methods in neuroscience began to emerge much later, leading investigators to examine the role of diet in health, including mental well-being, with greater precision. This review shows how short- and long-term forced dietary interventions bring about changes in brain structure, chemistry, and physiology, leading to altered animal behavior. Examples will be presented to show how diets alter brain chemistry, behavior, and the action of neuroactive drugs. Most humans and most animal species examined in a controlled setting exhibit a fairly reproducible pattern of what and how they eat. Recent data suggest that these patterns may be under the neurochemical and hormonal control of the organisms themselves. Other data show that in many instances food may be used unconsciously to regulate mood by seemingly normal subjects as well as those undergoing drug withdrawal or experiencing seasonal affective disorders and obesity-related social withdrawal. We will discuss specific examples that illustrate that manipulation of dietary preference is actually an attempt to correct neurochemical make-up.