Cytochemical Changes Research Articles

Doc-1-Mediated apoptosis in malignant hamster oral keratinocytes

Purpose: Cell cycle mediators involved in inducing apoptosis are frequently deregulated during carcinogenesis. Deleted in oral cancer-1 (doc-1) is an S-phase regulator that is inactivated during oral carcinogenesis. Transfection of doc-1 into malignant oral keratinocytes leads to increased cell loss. It is hypothesized that ectopic expression of doc-1 in hamster oral cancer cells induces apoptosis. Materials and methods: Malignant hamster oral keratinocytes ( wt-HCPC-1), which lack measurable doc-1 mRNA and protein, were previously transfected with eitehrn a CMV- doc-1 expression vector construct ( doc-HCPC-1) or the parental control vector pcDNA3 ( cv-HCPC-1). A trypan blue exclusion assay was performed to examine cell death in the parental or wild-type HCPC-1 keratinocytes, HCPC-1 transfected with the parental pcDNA3 vector, and the doc-1 transfected HCPC-1 cells. To examine whether ectopic expression of doc-1 mediates gross cellular changes consistent with apoptosis, toluidine blue-safranin differential staining and the quantitative fluorescent microscopy assays were performed. To identify early apoptotic cytochemical changes observed in the cell membrane and nucleus, annexin V/propidium iodide (PI) fluorescence-activated cell sorter (FACS) analysis and the terminal deoxytransferasemediated dUTP nick-end labeling (TUNEL) assay were performed. Results: Doc-HCPC-1 showed elevated numbers of dead cells over wt-HCPC-1 and cv-HCPC-1 in the trypan blue exclusion assay. Toluidine blue-safranin staining and quantitative fluorescent microscopy showed significant morphologic changes in the doc-I transfectants consistent with apoptosis ( P < .05). TUNEL assays ( P < .05) and annexin V/PI FACS analysis ( P < .05) also showed early cytochemical changes in the doc-HCPC-1 transfectants, confirming that ectopic expression of doc-1 induces apoptosis. Conclusions: These data suggest that doc-1 induces apoptosis in malignant hamster oral keratinocytes. It is hypothesized that doc-1 is a mediator of apoptosis that is inactivated during hamster oral carcinogenesis.

The Histochemical and Cytochemical Changes from Formative to Resorptive Osteocytes.

Based on their ultrastructural features, osteocytes have been classified into three phases: formative, resorptive, and degenerative. However, the mechanism of the morphological changes from formative osteocyte to resorptive osteocyte is still unclear. Therefore, we labeled bone matrix with calcein and examined chronologically the histochemical changes in osteocytes from two distinct areas in the mandible, focusing on the relationship between osteocytes and osteoclastic bone resorption. Tartrate-resistant acid phosphatase (TRAP) activity was detected only in osteocytes located near sites of osteoclastic bone resorption. Osteocytes far from osteoclasts lacked TRAP activity, even those that had been enclosed in bone matrix as long as the osteocytes that did show TRAP activity. Furthermore, glycogen granules evidenced by periodic acid-Schiff and the periodic acidthiocarbohydrazide-silver protein staining in osteocytes disappeared when the cell acquired TRAP activity. These findings suggest that the acquisition of TRAP activity in an osteocyte is closely synchronized with bone resorption. Disappearance of glycogen in osteocytes in the same area may also be related to the acquisition of TRAP activity or bone resorbing activity. The osteocytes characterized by glycogen accumulation must be in the phase that follows the formative phase, in which osteocytes display neither formation nor resorption activity.

Changes of cytochemical markers in the conjunctival and corneal epithelium after corneal debridement.

1. The aim of this study was to determine the epithelial changes of the conjunctiva and cornea up to 7 days after corneal debridement and the changes highlighted included (1) proliferation, (2) production of growth factor, (3) changes in calcium binding protein marker, (4) production of cytokine, and (5) maturity of the regeneration corneal epithelium. 2. The cytochemical changes of the corneal and conjunctival epithelia of rabbit were analyzed up to 7 days after debridement. 3. An increase in proliferating cell nuclear antigen (PCNA) was observed in the limbal epithelia 12 hr after lesion and reached a peak by 48 hr. 4. Some proliferating limbal cells also contained epidermal growth factor (EGF) beginning 24 hr after injury. The early limbal cell proliferation and the EGF production and their persistence until 7 days after lesion were likely involved with the process of regeneration. 5. Other positive markers appeared after lesion included tumor necrosis factor (TNFalpha) and calcium binding proteins S100A and S100B, which appeared mainly within the first 48 hr after lesion and then started to decline. The short appearance and the relatively small quantity of TNFalpha indicated that this cytokine was probably not very important in the repair process and its appearance might be related to the injury induced. The presence of S100A and S100B could be associated with both cell death after injury and the proliferation of new epithelium. 6. The cornea epithelium was still immature 7 days after lesion in that it still contained cytokeratin. 7. In conclusion, the critical hours of peak conjunctival and corneal changes after corneal debridement were in the first 2 days.

Neuropathological features of mesial temporal sclerosis: Histochemical studies of surgically resected specimens from patients with temporal lobe epilepsy

Mesial temporal sclerosis (MTS) is the most common pathological finding in temporal lobe epilepsy (TLE), but the relationship between MTS and hyperexcitability has not been defined. The neuropathological findings of MTS on the basis of our histochemical investigations using surgically resected specimens from patients with intractable TLE will be reviewed and discussed. Various sclerotic changes including neuronal loss and astrogliosis were observed not only in the hippocampus but also in the other mesial temporal structures such as the amygdala and entorhinal cortex. Moreover, aberrant residual pyramidal neurons were recognized, which showed morphological abnormalities; abnormal distribution of zinc, γ‐aminobutyric acid‐A receptor and glutamate decarboxy‐lase; and disorganization of the granule cell layer (dispersion and bilaminar distribution). Increases in density of the corpora amylacea and peripheral type benzodiazepine receptor binding corresponded with glial proliferation. Histochemical studies demonstrated the association of mossy fiber sprouting with synaptic reorg‐anization and changes of several chemically defined inter‐neuron systems in the dentate gyrus. Quantitative analysis using in vitro autoradiography showed that neurotrans‐mitter receptor bindings related to neuronal excitation (AMPA and NMDA receptor) and inhibition (central type benzodiazepine receptor) were reduced differently as a function of neuronal loss in MTS. These cytochemical changes associated with neurotransmitters and their receptors in the sclerotic hippocampus may constitute the pathological background of epileptogenesis in TLE.

Ultrastructural Alteration of Osteoclasts Treated with Brefeldin A and Wortmannin.

Osteoclasts secrete protons and lysosomal enzymes through ruffled borders, resulting in demineralization and degradation of bone matrix. Golgi apparatus is thought to play a key role in this process. In order to elucidate the specific functions of Golgi apparatus in osteoclasts, we observed the ultrastructural and cytochemical changes resulting from the administration of brefeldin A (BFA), an inhibitor of Golgi structures, and wortmannin (WT), an inhibitor of phosphatidylinositol 3-kinase (PI3-kinase). When treated with BFA, osteoclasts showed a dissociated Golgi apparatus, while the peanut agglutinin (PNA)-positive ruffled borders were poorly developed or disappeared. Moreover, the acid phosphatase (ACPase) activity was somewhat reduced. WT-treated osteoclasts, on the other hand, exhibited no ultrastructural alteration of the Golgi apparatus, but were marked by the disappearance of PNA-positive ruffled borders, and a consequent increase in the number of ACPase-positive vesicles and vacuoles in the cytoplasm. These results indicate that the Golgi apparatus of osteoclasts not only plays an important role in the formation of lysosomal enzymes but also the supply of ruffled border membranes. Furthermore, PI 3-kinase appears to be involved in the transport of lysosomal enzymes and the maintenance of ruffled borders.

The essentiality of histo- and cytochemical studies of skeletal muscle in the investigation of neuromuscular disease

American Academy of Neurology Dedicated to advancing the art and science of neurology, and thereby promoting the best possible care for patients with neurological disorders A Celebration of the First 50 years of the American Academy of Neurology Neurology 1962;12:778-794 In the investigation of neuromuscular disease, histologic examination of skeletal muscle biopsies is generally accepted as an important part both of routine diagnostic procedures and of more specialized research. The purpose of the present report is to establish that the use of histo- and cytochemical technics combined with light microscopy is also an essential aspect of both types of investigation. Substantiating evidence is presented in the form of 6 examples, chosen from recent studies, of cytopathologic changes in neuromuscular disease as demonstrated by these technics. Two fundamental types of abnormalities in skeletal muscle are detectable with histo- and cytochemical technics: (a) a generalized change of a given reaction, for example, loss of phosphorylase activity, and (b) a localized change of activity confined either to a specific type of muscle fiber (as in the new myopathy with rod-shaped structures) or to certain regions of individual muscle fibers (as in target fibers and central core disease). Further, if the cytochemical technics are sufficiently refined, they may be used to demonstrate the functional activity of fine structural components of the muscle cell. On the basis of such data, predictions can often be made as to the fine structural changes which electron-microscopy will reveal. It must be understood, though, that some cytochemical changes might not be accompanied by changes of fine structure and vice versa. Cytochemistry combined with electron-microscopy would give even more detailed information, but this approach has 2 major limitations: (a) only a very few cytochemical reactions are as yet refined enough to be used with electron-microscopy and(b) study of a large …

Cytochemical and morphological changes in cerebral neurons induced by δ-sleep peptide

Small neurons prone to chromophilia, with protein production decreased to 40%, were found in layer V of the sensorimotor cortex of rats with emotional fear induced by antistress δ-sleep peptide. These changes point to sedative effect of δ-sleep peptide in a stimulated focus.

HISTOPATHOLOGICAL AND HISTOCHEMICAL CHANGES IN HONEYBEE LARVAE (APIS MELLIFERAL.) AFTER INFECTION WITHBACILLUS LARVAE, THE CAUSATIVE AGENT OF AMERICAN FOULBROOD DISEASE

Morphological, histochemical and cytochemical changes were examined in honeybee larvae after infection with the bacteriumBacillus larvae. The results indicate cell necrosis in the midgut epithelium accompanied by increasing cell vacuolization and nuclear pyknosis followingper osinoculation withB. larvae.Many autolysosomes were positive for acid phosphatase. Non-vacuolar acid phosphatase activity was also found in lysed cell compartments. No such activity was found in regenerative epithelial cells. Degradation of haemocytes, salivary glands and other tissues was also observed. Histochemical analyses afterper cutaneousinoculation withB. larvaeof three- and five-day-old honeybee larvae show intense non-vacuolar acid phosphatase activity followed by disintegration of infected salivary glands, epithelial cell cytoplasm and haemocytes.

Morphological and cytochemical changes in human mast cells during culture

Mast cells were cultured from human umbilical cord blood CD34-positive cells in the presence of interleukin (IL)-6 and stem cell factor (SCF). Electron microscopically, a particulate or beaded structure, the prominent structure of tryptase-positive mast cell (T mast cell) granules, was frequently observed in 54-day cultures. Straight or coiled lamellae, often observed in the granules of tryptase-and chymase-positive mast cells (TC mast cells), were observed in the granules in 75-day cultures. Cytochemically, the peroxidase activity of the granules was positive but decreased during the term of culture. Glycogen particles were abundant in 54-day cultures, and scarce in 75-day cultures. These findings suggest that the mast cells matured and changed in phenotype during the culture's term.

Ozone-induced cytochemical and ultrastructural changes in leaf mesophyll cell walls

Cuttings of birch (Betula pendula Roth), poplar (Populus ×euramericana (Dode) Guinier cv. Dorskamp), and alder (Alnus glutinosa (L.) Gaertn.) were exposed in the open field to ambient ozone (O3), in both full sunlight and shade conditions, and in field fumigation chambers to filtered air (FA) or FA plus added O3 (75 nL·L n1 ) from 07:00 to 19:00, 19:00 to 07:00, or for 24 h. Appearance of O3-induced leaf symptoms was related to changes at the cellular level, especially in the cell wall. Changes were analyzed by light, fluorescence, transmission electron, and low-temperature scanning electron microscopy. Visible leaf symptoms appeared after 23n39 days of fumigation in chambers at all three elevated O3 regimes. Shaded birch showed increased sensitivity to ambient O3 compared with birch grown in sunlight. In the presence of visible O3 injury, mesophyll cell walls of birch and poplar leaves were thickened, and droplet-like exudates (projections) formed on cell walls adjacent to intercellular air spaces and increased as symptoms worsened. The main exudate constituents were esterified pectins (calcium pectate), a small amount of protein (more than in the cell wall proper), and callose (in poplar leaves only). These exudates indicate that O3 has caused a slow intercellular oxidative process to occur at the cell walls. Resume : Des boutures de bouleaux (Betula pendula Roth), de peupliers (Populus ×euramericana (Dode) Guinier cv. Dorskamp) et diaulnes (Alnus glutinosa (L.) Gaertn.) ont OtO exposOes, diune part, ‡ des concentrations diozone (O3) contenues dans liair ambiant en plein champ (en plein soleil ou ‡ liombre) et diautre part, dans des chambres de fumigation, ‡ de liair filtrO ou ‡ de liair filtrO enrichi diO3 (75 nL·L n1 ), de 07:00 h ‡ 19:00 h, ou de 19:00 h ‡ 07:00 h, ou pendant 24 h. Les symptUmes (dus ‡ liO3) visibles sur les feuilles correspondaient ‡ des modifications au niveau cellulaire, particulirement des parois de la cellule. Les changements constatOs ont OtO analysO ‡ liaide de microscopes optiques, ‡ fluorescence, Olectronique ‡ transmission et Olectronique ‡ balayage ‡ basse tempOrature. Les symptUmes visibles sur les feuilles des arbres sont apparus aprs 23n39 jours, aussi bien lors des fumigations nocturnes, diurnes ou en continu. ? liombre, la sensibilitO ‡ liO 3 ambiante des feuilles de bouleau Otait accrue. Lorsquiil y avait des symptUmes visibles sur les feuilles de bouleau et de peuplier, les parois des cellules du mOsophylle orientOe vers liespace aOrien intercellulaire siOpaississaient et formaient des callositOs, dont le nombre augmentait en fonction de la gravitO des symptUmes. Ces callositOs sont composOes de pectines estOrifiOes (sous forme de pectate de Ca), diune petite quantitO de protOines (mais en plus grande quantitO que dans la paroi cellulaire elle-mŒme), ainsi que de callose (seulement pour les feuilles de peupliers). Ces callositOs indiquent quiun lent processus dioxydation intercellulaire est en cours.

Influence of fluoride on secretory pathway of the secretory ameloblast in rat incisor tooth germs exposed to sodium fluoride.

Fluoride, which is an environmental toxicant, is a potent inducer of mottled enamel in humans and rats. To define the influence of fluoride on the secretory pathway in enamel fluorosis, mottled enamel was induced in the incisor tooth germs of rats by subcutaneous injections of sodium fluoride for 4 days, and then morphological and cytochemical changes of the secretory ameloblast were examined in the tooth germs with HRP-labeled lectin (Con A, GS-I, SBA and PNA) and En3 antibody labeling amelogenins. The accumulation of small vesicles on the route of the secretory pathway between the rER and the Golgi apparatus, disorder of Golgi stacks, and formation of abnormal large granules in distal cytoplasm were seen in the secretory ameloblast. Lectin staining patterns of the secretory ameloblast indicated the disturbance of the vesicular transport between the rER and the Golgi apparatus, and disorganization of the Golgi stack. Immunolabeling of the cell showed disruption of the sorting and fusion process on the secretory pathway. These results suggest that the fluoride disturbs the intracellular transport in the synthesis-secretory pathway of the ameloblast, and that this effect of fluoride on the synthesis-secretory pathway participates in the formation of enamel fluorosis.

Early hepatic changes induced in rats by two hepatocarcinogenic organohalogen pesticides: bromopropylate and DDT.

The aim of the present studies was to describe the effect of two organohalogen pesticides: DDT and bromopropylate, on early changes in rat liver, proposed in the literature to be useful endpoints in screening of non-genotoxic hepatocarcinogens and/or liver tumor promoters. We investigated the effects on the following endpoints: hepatomegaly, mitogenesis (DNA synthesis, mitotic activity, percentage of binuclear cells) and cytochrome CYP2B1-dependent monooxygenase induction. The histological and cytochemical changes in the liver were also recorded. Male Wistar rats received bromopropylate in one, three or five daily oral doses of 125, 250, and 500 mg/kg body wt. day-1. DDT was applied as one, three, and five daily oral doses of 24 mg/kg body wt. day-1 (this dose is close to the mean hepatocarcinogenic dose in male Wistar rats: 34.1 mg/kg body wt. day-1). In the case of both pesticides the early effects observed consisted of hepatomegaly accompanied by an increase in the p-nitroanisole O-demethylase activity and hepatocyte proliferation. Hepatocyte proliferation was elevated during the total experimental period. Vacuolated cytoplasm and evident focal necrosis may suggest that the maximal increase in hepatocyte proliferation, preceding hepatomegaly, is at least partly related to a regenerative liver response to pesticides. In addition to the above-mentioned early changes, the present findings provide new evidence for the occurrence of dose-dependent abnormal mitoses (and c-mitoses) in the hepatocytes of the bromopropylate and DDT treated rats.

Biochemical mediators of meningeal inflammatory response to group B streptococcus in the newborn piglet model.

The meningeal inflammatory response to a heat-killed mutant unencapsulated strain of type III group B Streptococcus (GBS) was studied in a newborn piglet model. GBS (10(9) colony-forming unit equivalents) or saline (control) was inoculated intraventricularly. Serial cerebrospinal fluid measurements were done at baseline and over the course of the next 24 h for cytochemical changes and production of tumor necrosis factor (TNF) and prostaglandins. In separate experiments, we defined the time course of early changes during the first 6 h and dose response relationship over a range of inocula 10(6) to 10(9) colony-forming unit equivalents. The intraventricular inoculation of the heat-killed unencapsulated GBS induced marked leukocytosis and increased protein by 6 h. These changes were preceded by a several hundredfold increase in TNF (maximum at 2 h) and prostaglandins (maximum at 2-4 h). The early and sharp rise in TNF suggests its pivotal role in initiating the inflammatory cascade. The magnitude of the inflammatory response increased with increasing bacterial dose over the range studied. To study the effect of encapsulation of GBS in the induction of meningeal inflammation, we compared the response to the unencapsulated mutant strain with that to the encapsulated parent strain. The encapsulated strain produced much smaller inflammatory changes, and only with high doses of bacteria. The GBS cell wall appeared to be the primary bacterial product triggering inflammation. Intraventricular injection of the heat-killed unencapsulated GBS with exposed cell wall can serve as a valid model for studying neonatal meningitis.

Division of Labor among Gonadotropes

This chapter has presented a somewhat complex view of the gonadotrope population, indicating that it consists of independent subsets. There may be regulatory cells that influence development and other ancillary processes needed for normal reproduction. For example, normal differentiation of PRL cells requires a functioning population of gonadotropes (Kendall et al., 1991). In addition, gonadotropes appear to be autoregulatory; subsets may produce inhibin or activin (in rats) and follistatin. Production of GnRH itself may serve as another regulatory tool. The gonadotrope population appears to be quite dynamic and convertible in the female rat. Cytological and cytochemical changes with the stage of the cycle are obvious. Increases in the numbers of immunoreactive gonadotropes parallel increases in GnRH target cells and culminate in peak expression of LH and FSH beta subunit mRNAs. The immunoreactive gonadotropes are greatly reduced after the surge activity, as though the cells had disappeared from the population. However, gonadotropes can still be detected by their content of gonadotropin mRNAs. This finding has led to the hypothesis that the gonadotropes recycle themselves. However, do they go through a resting phase? Is there a normal cycle of cell death and turnover? These are basic questions that must be answered in order to understand how the population is organized and renewed. Finally, we have returned to one of our original problems. Whereas it is clear that nonparallel release can be brought about by granules or cells with only one gonadotropin, the exact mechanisms that sort the gonadotropin molecules or turn off bihormonal expression are not known. A combination of autoregulatory events involving follistatin, activin, inhibin, and possibly steroids may play a role in modulating expression by a given subset. Delays in maturation may also prevent secretion of FSH and, hence, effect the delayed rise seen during late proestrus. The nonsecretory FSH cells seen in the studies by Lloyd and Childs (1988a) may be delayed maturers, requiring additional receptor types or changes in the calcium flux pattern to secrete their product. We also have a new question to address. What is the significance of the presence of GH in proestrous gonadotropes? Is GH a regulatory hormone, bound to receptors inside gonadotropes, or do subsets of somatotropes augment the population, producing a cocktail of GH and gonadotropins to aid ovulation? Either hypothesis is intriguing. Co-storage of GH and gonadotropins would be an efficient way of providing the hormones needed by the ovary. However, further work with in situ hybridization is needed to detect GH mRNA in such cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Ultrastructural changes in mitochondria of the adrenal cortex of iron-deficient rats.

Male Sprague-Dawley rats aged 3 weeks that were maintained on an iron-deficient diet for 4-5 weeks developed severe anemia with markedly reduced hemoglobin levels (4.11 +/- 0.20 Hb g% versus controls 12.74 +/- 0.15 Hb g%). On sacrifice, the adrenal glands were removed and processed for light and transmission electron microscopy and enzyme cytochemistry. The major histological and ultrastructural changes in the adrenal cortex in response to the iron deficiency were seen in cells of the zona fasciculata, especially in its outer region, and to a lesser degree in cells of the zona reticularis. Structural changes were seen in the mitochondria of these cells, which often became grossly enlarged and developed unusual electron-dense inclusions. In addition, the lipid droplets in the iron-deficient cells of these regions were much less developed and less prominent compared with controls. Quantitative cytochemical localization of succinic dehydrogenase (SDH) activity in the adrenal glands showed that in iron-deficient rats there was an increase in SDH activity in the zona fasciculata (46%) and in the zona reticularis (74%), whereas there was a reduction of approximately 41% in SDH activity in the zona glomerulosa. Serum corticosterone levels were significantly raised in the iron-deficient rats compared with the control rats. Our results indicate that severe nutritional iron deficiency in rats causes ultrastructural and cytochemical changes in the mitochondria of the adrenal cortex accompanied by increased secretion of corticosterone.

Adjuvant-induced inflammation of rat paw is associated with altered calcitonin gene-related peptide immunoreactivity within cell bodies and peripheral endings of primary afferent neurons.

Local inflammation is associated with profound changes in the biochemistry and physiology of primary afferent nerve fibers and the central neurons responding to their signals. In some tissues, the neural changes accompanying inflammation include sprouting and cytochemical changes that are delayed several days after the initial injury. In the present study, we have analyzed the effect of complete Freund's adjuvant (CFA)-induced inflammation in the rat paw on calcitonin gene-related peptide (CGRP) immunoreactivity (IR) in dorsal root ganglia and within tissue of the inflamed paw. We quantified the CGRP-IR within the L1, L4, and L6 ganglia, and in ankle, midpaw, joint and toe tissues. Analysis of the processed tissue revealed a significant increase in the percentage of CGRP-positive cells within L4 dorsal root ganglia ipsilateral to an inflamed hindpaw six days after administration of CFA. There was a parallel increase in the number and staining density of detectable CGRP-immunoreactive fibers in periarticular and perivascular tissues of the inflamed digits and inflamed ankle. The other tissues of the paw, including epidermis and the regions surrounding the abcesses, did not have detectable changes in CGRP-immunoreactive fibers, despite tissue swelling and dystrophic changes in the foot that included loss of mast cell staining. These data demonstrate that local inflammation of the rat paw has delayed influences on the peripheral nervous system, in addition to a number of previously characterized acute effects. The alterations of CGRP-IR were focused around specific tissue types, such as joints and subdermal blood vessels, and absent from others, such as epidermis or in the areas surrounding abscesses. This suggests production of local factors within reactive tissues that selectively interact with nerve fibers to induce changes in CGRP-IR within the fibers.

Dexamethasone treatment reduces sensory neuropeptides and nerve sprouting reactions in injured teeth

Dental injuries have been shown to generate extensive structural and cytochemical changes in sensory fibers that contain neuropeptides such as calcitonin gene-related peptide (CGRP) or substance P (SP). The present study was designed to test whether the anti-inflammatory drug dexamethasone (DEX) can alter neural responses to dental injuries. DEX (20 μg/100 g body weight) was given to adult rats (n = 10) prior to dental surgery and daily thereafter for 4 days. Control animals received sterile saline vehicle (n = 6) or no injection (n = 1). Each rat was then anesthetized for dental surgery and a cavity was drilled partway through dentin on the anterior side of the right maxillary first molar. Pulp exposure injuries were also made on two right mandibular molars in 14 of 17 rats. After 4 days of daily drug treatment, the rats were anesthetized and fixed by perfusion with formaldehyde-picric acid, and their jaws were prepared for immunocytochemistry. Neural CGRP immunoreactivity near the maxillary cavity injury site of DEX-treated rats was reduced more than 50% compared to controls, as determined both qualitatively and by digital analysis. The SP immunoreactive (IR) fibers in molar pulp also had extensive inhibition of neural reactions to cavity injury. DEX also reduced the immunoreactivity for CGRP and SP in normal contralateral rat molars of all treated rats, and it caused a postoperative loss of weight. Pretreatment for 1–5 days prior to the 4 day injury gave the same results as pretreatment for 1 h. The mandibular pulp exposure injuries induced a chronic abscess and advancing pulpal necrosis but did not show differences in nerve reactions between DEX-treated rats and the controls. In conclusion, the synthetic steroid dexamethasone suppressed the CGRP and SP neuropeptide immunoreactivity in normal dental nerves and it reduced nerve-sprouting responses to dentin cavity injuries; however, sensory nerve reactions to pulpal exposure injuries were not affected by DEX in these experiments.

Cortical responses in Japanese black pine to attack by the pine wood nematode

Anatomical and cytochemical changes in the current-year stem cuttings of Japanese black pine (Pinus thunbergii) were investigated in the early stage of infection by a virulent isolate and an avirulent isolate of pine-wood nematode (Bursaphelenchus xylophilus), and an avirulent isolate of another nematode species, Bursaphelenchus mucronatus. Accumulation of lignin- and suberin-like substances around the resin canals in the cortex was shown as a new symptom of the infection by these isolates. Experiments with girdled cuttings demonstrated that more nematodes inhabit and move in the bark than in the xylem and pith at the early stage of infection by the virulent isolate. Death of pine cells occurred first in the epithelial cells of resin canals in the cortex after inoculation with the virulent isolate and then in the cortex and periderm, pith and xylem, and finally the cambium. In branches of 5-year-old seedlings inoculated with avirulent and B. mucronatus isolates, wound periderm was formed surrounding resin canals in the cortex, and cortical cells surrounding the wound periderm were alive. Evidence indicates that nematodes first enter resin canals in the cortex and then invade the surrounding cortical tissue, and that the ability of the virulent nematodes to move into the cortical tissue may be greater than that of the other isolates, accounting for differences in virulence. Key words: Bursaphelenchus xylophilus, Bursaphelenchus mucronatus, virulence, periderm, pine wilt disease, pine-wood nematode.

Cytochemical changes during laser therapy on inflammations of the genitalia in agroecologically unfavorable regions

Cytochemical changes during laser therapy on inflammations of the genitalia in agroecologically unfavorable regions

Adrenal and vagus modulation of cisplatin-induced gastric emptying and ulceration

Cisplatin is a most valuable broad spectrum antineoplastic drug available for the treatment of testicular and ovarian cancers. It has several severe toxic side effects of which gastrointestinal and nephrotoxicity are the major dose limiting. It also induces hypocalcemia and Hypomagnesemia that have been demonstrated to effect the secretory activity of the neurohypophysis and the parathyroid glands. In rats cisplatin treatment causes stomach bloating and ulceration that can be ablated by daily injections of calcium just before the treatment and during the treatment or using vagotomy. Adrenalectomy has also been shown to prevent ulceration. Present study is an effort to determine the effect of cisplatin on morphological and cytochemical changes in the neuromuscular interactions of the stomach smooth muscle and the adrenal glands before and after vagotomy.Male Wistar rats [Crl:(WI)BR] weighing 200-300 g were given intraperitoneal injection of 9 mg/kg in 0.85% saline. Alternate group of animals received in addition daily injections of calcium (1 ml of 1.3% calcium chloride).