Study on Blood Biochemical Diagnostic Indices for Hepatic Function Biomarkers in Endemic Skeletal Fluorosis

The aim of the study was to determine the relationship of fluoride in drinking water to liver function in individuals living in normal and seven endemic fluorosis areas of Punjab, India. The concentration of fluoride in drinking water of different areas varied from 5.9 to 24.5 mg/L. Study group consisted of 705 patients in the age group between 20 and 60 years (mean age of 39.35 ± 11.27) affected with osteodental fluorosis were compared with 300 age- and sex-matched controls (with mean age of 35.28 ± 8.25 years). Biochemical data was analyzed by one-way analysis of variance (ANOVA) with post hoc Tukey–Kramer and Bonferroni multiple comparison tests. The relationship between hepatic enzymes was calculated by Pearson’s correlation and linear regression. The results revealed significantly (P < 0.001) higher concentration of serum fluoride in patients when compared to control. The mean activities of cyclic adenosine monophosphate (AMP), alkaline phosphatase (ALKP), acid phosphatase (ACP), aspartate aminotransaminase (AST), and alanine aminotransaminase (ALT) were significantly (P < 0.05–0.001) elevated in patients from all fluoride areas. ANOVA with post hoc Turkey–Kramer and Bonferroni multiple comparison test demonstrated a significant (P < 0.0001) variance in the activities of cAMP, ALKP, ACP, AST, and ALT in fluorotic patients, with elevation in water fluoride levels. Maximum elevation of 196.14% (ACP), 99.31% (cyclic adenosine monophosphate; cAMP), 72.08% (ALT), 60.14% (AST), and least 21.35% (ALKP) was recorded in patients exposed to 24.5 mg/L fluoride in drinking water. There was positive correlation between water fluoride, serum fluoride and AST (r = 0.77, 0.91), ALT (r = 0.82, 0.90), ALKP (r = 0.88, 0.97), and ACP (r = 0.74, 0.85). Pearson’s correlation demonstrated highly significant (P < 0.05) positive relationship between water fluoride and cAMP (regression equation: Y = 0.9807 ×+ 22.081 Y = 0.9807 \times + 22.081 , = 0.84; r = 0.92, P < 0.05). The increased levels of transaminases in fluorotic patients suggest alteration in liver functions. The level of alkaline and acid phosphatase was increased during fluoride intoxication which is also an early marker of hepatic cell damage because of its specificity and catalytic activity. The elevated levels of enzymes are reflective of bone disorders, which are characterized by increased osteoblastic activity. There levels increased several times if cellular damage occurs in the liver. The results suggest that fluoride exposure intensifies the activities of hepatic function enzymes in osteofluorosis.     

Effects of Fluoride on Synaptic Membrane Fluidity and PSD-95 Expression Level in Rat Hippocampus

The objective of this study is to investigate the neurotoxicity of drinking water fluorosis on rat hippocampus. Just weaning male Sprague–Dawley rats were randomly divided into four groups and given 15, 30, and 60 mg/L NaF solution and distilled water, respectively, for 9 months. The fluidity of brain synaptic membrane and expression level of postsynaptic density 95 (PSD-95) were tested. Results showed that the fluidity of brain synaptic membrane decreased gradually with increasing of fluoride concentration, and it was significantly decreased (P < 0.05) in moderate-fluoride group compared with control group, and expression level of PSD-95 was significantly decreased (P < 0.01) in moderate-fluoride group when compared with that of control group. These results indicate that decrease of synaptic membrane fluidity and PSD-95 expression level may be the molecular basis of central nervous system damage caused by fluoride intoxication; PSD-95 in CA3 region of hippocampus is probably a target molecule for fluoride.     

Ultrastructural morphometric analysis of ameloblasts exposed to fluoride during tooth development

Since a considerable amount of the world population is exposed to high doses of fluoride, it is of special concern to investigate its action mechanisms during dental enamel development. In this study, the toxicity of fluoride in ameloblasts during enamel development was evaluated by means of ultrastructural morphometric analysis. A total of 18 male Wistar rats were distributed into three groups. In Group I, the animals received deionized drinking water ad libitum (negative control) and in Groups II and III, they received sodium fluorided (NaF) drinking water at doses of 7 and 100 ppm ad libitum, respectively, for 6 weeks. Morphometric data were expressed as volume density of the most significant organelles present in the secretory and maturation phases of amelogenesis such as RER, granules, lysosomes, phagic vacuoles, microfilaments and mitochondria. The results showed that the volume density of mitochondria in the 100 ppm experimental group was 29% (P < 0.05) higher than the control group in secretory ameloblasts. No remarkable differences were found in maturation ameloblasts for all organelles evaluated. Taken together, these data indicate that NaF at high doses is able to induce cellular damage in secretory ameloblasts, whereas no noxious effect was observed during maturation stage of amelogenesis as depicted by ultrastructural analysis.     

Fluoride-induced lesions in the teeth of the short-tailed field vole (Microtus agrestis): A description of the dental pathology

The effect of fluoride on the appearance of the teeth of the short-tailed field vole. Microtus agrestis, was investigated in both wild animals collected from field sites affected by different levels of industrial fluoride contamination and laboratory-reared animals consuming experimental grass diets of known fluoride concentration or with known fluoride concentrations in drinking water. The extent and severity of lesions on the surface and structure of both incisors and molars are described as six lesion types and related to the amount of biologically available orally ingested fluoride. In the incisors of voles consuming relatively low fluoride diets, lesions are mainly confined to those resulting from disruption of enamel pigmentation expressing itself as concentric bands of pigmentation-free areas on incisor surfaces. The visible effects on molars at low fluoride levels are confined to minor alterations in surface appearance. At higher levels of available dietary fluoride, effects on enamel pigmentation are superseded by alterations in the formation, composition, and strength of both enamel and dentine. The incisors exhibit a marked to severe increase in the cutting tip erosion rates with comparable increases in the extent of abnormal surface changes (enamel hypoplasia) and loss of enamel pigmentation. The grinding surfaces of molars from animals exposed to high levels of dietary fluoride exhibit increasingly severe erosion of outer enamel regions, combined with cavitation and staining of the exposed central dentine. The mechanisms through which fluoride elicits increasingly visible and pathological alterations to the surface and subsurfaces of rodent teeth are discussed. J Morphol 232: 155–167, 1997. © 1997 Wiley-Liss, Inc.     

High Concentration of Fluoride Can Be Increased Risk of Abortion

The presence of fluoride in drinking water can be either beneficial or harmful for human health, depending on its concentration. Most adverse effects of fluoride are observed at high concentrations (above 1.5 mg/L). This study was aimed to evaluate the effect of fluoride concentrations in drinking water on spontaneous abortion in two regions: one with low fluoride concentration and another with high fluoride concentration. The results showed that there is a relationship between the concentration of fluoride in drinking water and abortion, so that the risk of abortion increased at high concentrations of fluoride. However, further studies are needed to clarify this relationship due to the small area and population in this study.     

Age estimation and growth layer patterns in teeth of crabeater seals: A comparison of techniques

Age estimation of marine mammals provides important information about ecological and life history parameters. Counting growth layer groups (GLGs) in the dentine and cementum of teeth is the most common technique for age estimation in pinnipeds. In this study, we used acid-etched canines (n = 38) and decalcified stained postcanine sections (n = 40) to calibrate readings in mummified crabeater seals (Lobodon carcinophaga). A subsample of this group received a prior cleaning treatment of boiling the teeth with hydrogen peroxide (H₂O₂). Ages ranged from 0 to 31 years. Dentine from canines and cementum from postcanines showed higher estimated ages (maximum 31 years) than dentine from postcanines (maximum 24 years), mainly in those teeth that did not receive prior treatment. Boiling with H₂O₂ has shown to affect cementum structure and, thus, results in underestimated ages, but dentine did not seem to be affected. The results presented here showed that ages can be estimated for the crabeater seal regardless of which tooth/tissue or method is used, at least for seals <13 years old. However, nontreated, stained thin sections of postcanine teeth are recommended because more reliable age estimations in older crabeater seals are obtained.     

Fluoride Alters Serum Elemental (Calcium,Magnesium, Copper,and Zinc) Homeostasis Along with Erythrocyte Carbonic Anhydrase Activity in Fluorosis Endemic Villages and Restores on Supply of Safe Drinking Water in School-Going Children of Nalgonda District,India

The present study aimed to determine the serum trace elements (copper (Cu), zinc (Zn), calcium (Ca), magnesium (Mg)) along with erythrocyte carbonic anhydrase (CA) activity and effect of intervention with safe drinking water for 5 years in the school children of fluorosis endemic area. For this purpose, three categories of villages were selected based on drinking water fluoride (F): Category I (control, F?=?1.68 mg/L), category II (affected F?=?3.77 mg/L), and category III (intervention village) where initial drinking water F was 4.51 mg/L, and since the last 5 years, they were drinking water containing <?1.0 mg/L F. The results revealed that urinary F was significantly (P?<?0.05) higher in category II compared to categories I and III. A significant (P?<?0.05) increase in serum Cu and Mg was observed in category II compared to category I. Serum Zn and Ca was significantly (P?<?0.05) decreased in categories II and III compared to category I. The erythrocyte CA activity was decreased in the category II compared to category I. However, in the category III, erythrocyte CA activity was comparable to the control group. In conclusion, F exposure altered elemental homeostasis which has restored to some extent on intervention by safe drinking water for 5 years in school-going children.     

Histology of tooth attachment tissues and plicidentine in Varanus (Reptilia: Squamata), and a discussion of the evolution of amniote tooth attachment

Few recent studies have examined the histological basis for tooth attachment in squamates. In the past few years, a surge of interest in this topic has led to the intriguing suggestion that the major tissues derived from the tooth germ (enamel, dentine, cementum and alveolar bone), are conservative and are present in all amniotes. In this study, we describe the histology and development of the tooth attachment complex in Varanus rudicollis, the rough‐neck monitor. We provide the first published evidence for the role of cementum and alveolar bone in tooth attachment in varanoid lizards. In Varanus, cementum is deposited on the external surface of the tooth root as well as at the base of the tooth, where it plays a role in the attachment of the tooth to the jawbone. Alveolar bone is also involved in tooth ankylosis. Our results support the hypothesis that the major tooth germ tissues are found in all amniotes. We provide insights into the structure and development of plicidentine, defined as infolding of the dentine around the tooth base. This feature is unique to varanoids among extant tetrapods and is the third tissue implicated in tooth attachment in Varanus. Plicidentine develops asymmetrically along the labial‐lingual axis of a tooth. Varanus is characterized by the presence of both primary and higher‐order lamellae, which anastomose to form a honeycomb‐like surface that then interacts with the more basal attachment tissues. J. Morphol. 2011. © 2011 Wiley‐Liss, Inc.     

Association of Hypertension,Body Mass Index,and Waist Circumference with Fluoride Intake; Water Drinking in Residents of Fluoride Endemic Areas,Iran

Hypertension is becoming a global epidemic for both rural and urban populations; it is a major public health challenge in Iran. Fluoride can be a risk factor for hypertension. Cross-sectional analysis was conducted in two study areas to assess the relation of fluoride with blood pressure prevalence, BMI, waist circumference, and waist-to-hip ratio (WHR) among different age groups in both sexes. The mean value of fluoride concentration in the drinking water from the four study villages varied from 0.68 to 10.30 mg/L. The overall prevalence of HTN and prehypertension in all subjects was 40.7%. The prevalence of isolated systolic hypertension, isolated diastolic hypertension, systolic-diastolic hypertension, and prehypertension in the total sample population was 1.15, 0.28, 9.53, and 29.76%, respectively. The odd ratio of hypertension in residents who drank water with high fluoride levels was higher than that in residents who drank water with lower level of fluoride (OR 2.3, 1.03–5.14). Logistic regression results showed that age (P?<?0.001), sex (P?=?0.018), BMI (P?=?0.015), and the fluoride level in drinking water (P?=?0.041) had a significant relationship with increased blood pressure. There were no statistically significant correlations between fluoride and BMI, hip circumference, and waist to hip ratio (WHR). The findings of this study are important for health care personnel and policymakers.     

Plasma and liver selenium levels in the rat during supplementation with 0.5, 2, 6, and 15 ppm selenium in drinking water

Plasma and liver selenium of Wistar rats were determined after 1, 3, and 6 mo supplementation with 0.5, 2, 6, or 15 ppm selenium as sodium selenite in drinking water. Plasma selenium was not different from control values at additional intake of 0.5 ppm but increased above usual levels at higher intakes. A highly significant correlation was observed between the total quantity of selenium ingested and plasma selenium after 1 mo treatment (r=0.99,p<0.01), but was less pronounced after 3 and 6 mo (0.94,p<0.05, and 0.78,p<0.05, respectively). The decrease in plasma selenium with time of treatment was more pronounced at higher intakes. There was also a highly significant correlation between total selenium intake and liver selenium concentration (r=0.99,p<0.01) after 1 mo of treatment, but this time liver selenium did not change with time, and the correlation remained highly significant throughout the investigation. Liver selenium therefore appears as a more sensitive and more representative measure of selenium intake than plasma selenium. Most supplements did not affect body weight and survival of animals, except when the diet was supplemented with 15 ppm for 6 mo; however, alterations in biochemical parameters concerning lipid status and hepatic function were observed at levels above 2.0 ppm.     

Litterfall and nutrient returns in red alder stands in western Washington

Summary Litterfall was collected over 1 year from eight natural stands of red alder growing on different sites in western Washington. The stands occurred at various elevations and on different soils, and differed in age, basal area, and site index. Most litterfall was leaf litter (average 86 percent). Amounts of litterfall and leaf litter varied significantly (P<0.05) among the sites. Average weights of litterfall and leaf litter in kg ha^–1 yr^–1, were 5150 and 4440, respectively. Weight of leaf litter was not significantly (P<0.05) related to site index, stand age, or basal area. The sites varied significantly (P<0.05) in concentrations of all elements determined in the leaf litter, except Zn. Average chemical concentrations were: N, 1.98 percent; P, 0.09 percent; K, 0.44 percent; Ca, 1.01 percent; Mg, 0.21 percent; S, 0.17 percent; SO₄–S, nil; Fe, 324 ppm; Mn, 311 ppm; Zn, 53 ppm; Cu, 13 ppm; and Al, 281 ppm. There were significant correlations between some stand characteristics and concentrations of some elements, and among the different chemical components of the leaf litter. Important correlations were found between stand age and P concentration (r=–0.84,P<0.01); weight of leaf litter and P concentration (r=0.74,P<0.05); weight of leaf litter and K concentration (r=0.71,P<0.05); concentrations of N and S (r=0.81,P<0.05); and concentrations of Fe and Al (r=0.98,P<0.01). Returns of the different elements to the soil by leaf litter varied among the different sites. Average nutrient and Al returns, in kg ha^–1 yr^–1, were: N, 82; Ca, 41; K, 19; Mg, 8; S, 7; P, 4; Fe, 1; Mn, 1; Al, 1; Zn, 0.2, and Cu, <0.1.     

Fluoride exposure and factors affecting dental caries in preschool children living in two areas with different natural levels of fluorides

BackgroundSuccessful oral health interventions must be based on the specific needs of the population that they serve. Evaluation of habits related to dental caries development and estimation of fluoride exposure in a target group of young patients helps to plan effective and safe caries prevention strategies.ObjectivesThe study aimed to evaluate factors affecting dental caries experience and sources of fluoride exposure in preschool children living in two areas: with optimal and low natural content of fluoride in drinking water.Materials and methodsThe study included a group of 73 children of both sexes aged 4–7 years attending two kindergartens in Środa Wielkopolska and Turek (Wielkopolska Voivodeship, Poland), where the content of fluoride in drinking water according to data obtained in the sanitary station ranged from 0.68 to 0.74 mg/L (optimal concentration of fluoride) and from 0.19 to 0.30 mg/L (low concentration of fluoride), respectively. Parents of patients completed a survey about diet, hygiene, and dental care, taking into account the child's fluoride exposure. The calibrated dentist assessed the oral health condition using a mirror, a CPI probe, and a headlamp. Oral hygiene was recorded using the Silness and Löe plaque index, caries experience by calculating the numbers of decayed, missing, and filled primary, and permanent teeth (dmf and DMF, respectively) while caries frequency by calculating the percentage of children with caries experience above 0. In order to assess the fluoride concentrations in urine and drinking water, parents were asked to provide a urine sample collected on fasting and a tap water sample. Fluoride concentrations were assessed using a 09–37 (MARAT) fluoride ion-selective electrode and a RAE 111 silver-chloride reference electrode. Statistical analysis was conducted using the data analysis software system Statistica (version 12, StatSoft, Inc. 2014), assuming a statistical significance level p < 0.05.ResultsNo statistically significant differences were found between caries indices of the examined children in each kindergarten (p > 0.05). Urinary fluoride levels were higher in children who tended to swallow toothpaste or used fluoride rinses and positively correlated with fluoride concentrations in the drinking water. Dental caries experience in the examined children depended on the effectiveness and frequency of oral hygiene procedures and dietary habits.ConclusionsThe strategy aimed at improving the oral health of the examined group of children should include accomplishing oral hygiene, promoting a non-cariogenic diet, and, finally, controlling fluoride exposure from at-home fluoride products. Caries prevention program ought to be adjusted to individual characteristics of each child, taking into consideration oral hygiene practices, dietary habits and total fluoride intake.     

Gastrointestinal Absorption and Renal Excretion of Fluoride After Ingestion of a High-Fluoride Dentifrice

This study aimed to evaluate the gastrointestinal absorption and renal excretion of fluoride after the ingestion of high-fluoride dentifrice. Twelve volunteers participated in this in vivo, crossover, and blinded study. In three experimental phases, the volunteers were randomly assigned to one of three treatment groups, who ingested either the following: distilled and deionized water (control), conventional dentifrice (1100 μg/g), or high-fluoride dentifrice (5000 μg/g). Both dentifrices contained fluoride in the form of NaF/SiO₂. To determine the rate of fluoride absorption, non-stimulated saliva was collected for up to 120 min after ingestion and the area under the curve of the salivary fluoride concentration was plotted as a function of time and the maximum concentration determined. All urine produced during the 24 h before and after ingestion was collected, and urinary excretion was calculated from the difference between the urinary fluoride concentrations in the two periods. A specific ion electrode coupled to an ion analyzer was used to measure fluoride concentrations. Statistical analysis was performed by ANOVA followed by Tukey’s test with p set at 5%. All measured parameters were highest after the ingestion of the dentifrice with 5000 μg/g (p < 0.001), confirming that this has an increased level of bioavailable fluoride compared with the conventional dentifrice. The high-fluoride dentifrice increases the concentration of salivary fluoride, which may explain its greater anticaries effect. However, it poses a potential risk of causing dental fluorosis and so should not be used by children.

     

Variations in concentration of fluoride in blood plasma of pregnant women and their possible consequences for amelogenesis in a fetus

The aim of the study was to assess the fluoride exposure of pregnant women living in Poznan (Poland) by examination of fluoride levels in blood plasma.

The subjects of the study were 31 pregnant women aged 22–34 years in the course of regular pregnancy. Data concerning the sources of fluoride exposure such as diet, oral hygiene measures and topical application of fluoride procedures, were collected from each individual with a questionnaire. Samples of blood plasma were drawn in the 28th, 33rd week of pregnancy and during delivery. The analysis evaluating the fluoride concentration in the samples was carried out with the use of fluoride electrode ORION (model 96-09). The data were statistically analyzed using the program Statistica for Windows.

Mean value of fluoride concentration in the samples of blood plasma from the 28th week of pregnancy was lower than the mean concentration detected in the 33rd week of pregnancy (3.29 and 3.73 μmol/l, respectively). These values suggest that apart from drinking water, there were other important sources of fluoride in the examined sample.

The results indicate that a reliable assessment of fluoride exposure in a given population cannot be based solely on the concentration of fluoride in drinking water. Relatively high levels of fluoride in blood plasma of examined women suggest that there is no need for fluoride supplementation in this group of patients.     

Modulation of plasma arginine vasopressin during rehydration in the Bedouin goat

When severely dehydrated Bedouin goats were allowed to drink to satiation their plasma arginine vasopressin concentration immediately dropped from a value of 19.9±9.4 pmol·l^-1 to 9.4±3.9 pmol·l^-1 (P<0.05). It continued to drop further until a concentration of 1.8±2.9 pmol·l^-1 was recorded, similar to that reported for goats allowed to drink freely. When the goats were shown the water but drinking was denied, plasma arginine vasopressin immediately dropped to 11.7±4.0 pmol·l^-1 (P<0.05) and further decreased to 10.0±4.8 pmol·l^-1 5 min following their sighting the water. This level, however, was not sustained and 2 h after the initial drop the high pre-trial concentration of plasma arginine vasopression was regained. Presumably, sighting of water by dehydrated goats induces an abrupt drop in their plasma arginine vasopressin level even before drinking commences. When rehydrated, by introducing water directly to the rumen, circumventing both the sensing of the water and the drinking proper, no immediate drop in the plasma arginine vasopression concentration of the newly rehydrated goats was observed. A delayed drop in the plasma arginine vasopressin levels took place slowly, concurrently with the drop in osmolality and concentration of Na⁺ in the plasma. It is suggested that sighting of water by dehydrated goats is involved in the modulation of plasma arginine vasopressin.     

Climatic influences on human body size and proportions: Ecological adaptations and secular trends

This study reevaluates the long-standing observation that human morphology varies with climate. Data on body mass, the body mass index [BMI; mass (kg)/stature (m)²], the surface area/body mass ratio, and relative sitting height (RSH; sitting height/stature) were obtained for 223 male samples and 195 female samples derived from studies published since D.F. Roberts' landmark paper “Body weight, race, and climate” in 1953 (Am. J. Phys. Anthropol. 11:533–558). Current analyses indicate that body mass varies inversely with mean annual temperature in males (r = −0.27, P < 0.001) and females (r = −0.28, P < 0.001), as does the BMI (males: r = −0.22, P = 0.001; females: r = −0.30, P < 0.001). The surface area/body mass ratio is positively correlated with temperature in both sexes (males: r = 0.29, P < 0.001; females: r = 0.34, P < 0.001), whereas the relationship between RSH and temperature is negative (males: r = −0.37, P < 0.001; females: r = −0.46, P < 0.001). These results are consistent with previous work showing that humans follow the ecological rules of Bergmann and Allen. However, the slope of the best-fit regressions between measures of body mass (i.e., mass, BMI, and surface area/mass) and temperature are more modest than those presented by Roberts. These differences appear to be attributable to secular trends in mass, particularly among tropical populations. Body mass and the BMI have increased over the last 40 years, whereas the surface area/body mass ratio has decreased. These findings indicate that, although climatic factors continue to be significant correlates of world-wide variation in human body size and morphology, differential changes in nutrition among tropical, developing world populations have moderated their influence. Am J Phys Anthropol 106:483–503, 1998. © 1998 Wiley-Liss, Inc.     

Isotopic composition and identification of the origins of individuals buried in a Neolithic collective grave at Bronocice (southern Poland)

The oxygen present in a human organism comes from numerous sources, but the major factor that causes variation in the isotopic composition of this element in a tissue is available drinking water. The isotopic ratio of oxygen in an organism's tissue, including that found in bones and teeth, reflects the isotopic oxygen composition typical for the area where a given individual developed and lived.Of particular interest with regard to this issue were a series of skeletons from the multiple grave discovered at the Funnel Beaker-Baden settlement at Bronocice (southern Poland). The question therefore arose whether the specimens buried in this grave were part of the local community.The oxygen isotope level was established using apatite isolated from bones or teeth. A femur and root dentine samples taken from permanent teeth were subjected to oxygen isotope analysis. The oxygen isotope level of the site was established on the basis of local water precipitation and measurements taken from the oxygen isotope concentration in apatite samples isolated from the bones of animals co-occurring with the studied human group.It has been found that the oxygen isotope levels in the bones and dentine of almost all the analysed specimens from the excavated site at Bronocice were within the established range for the area's environment, providing evidence for their local origin. Thus, it can be assumed that the analysed group inhabiting the macrosettlement at Bronocice during the Funnel Beaker phase of the Baden culture was most probably of local origin.     

The determination of urinary fluoride/creatinine ratio (Q) in monitoring fluoride intake

Linear correlation (r = 0.6811, p less than 0.001) was found between the 24 hour urinary excreted fluoride quantity and fluoride/creatinine ratio (Q) of the morning urine sample of 21 school children living in a children's home in Hungary. The mean value of fluoride/creatinine ratio (Q) in groups of children from eight different parts of Hungary, also showed linear correlation (r = 0.9720, p less than 0.001) with the measured fluoride concentration of drinking water. The urinary fluoride/creatinine ratio (Q) seems sufficiently informative for controlling fluoride intake in the course of caries preventive field studies.     

Effect of maternal exposure of fluoride on oxidative stress markers and amelioration by selected antioxidants in developing central nervous system of rats

Fluoride has been implicated as a pathologic mediator of fluorosis. Interestingly neuronal destruction, synaptic injury occurs by a mechanism involving oxidative stress, however, its effects in developmental stages of life, during maternal fluoride exposure and amelioration are not elucidated. In the present study, pregnant Wistar albino rats were exposed to 50 and 150 ppm fluoride in drinking water during gestation and post gestation. After parturition the pups born to the experimental animals were administered daily with selected antioxidants for 21 consecutive days. Fluoride administration substantially enhanced fluoride accumulation, lipid peroxidation and decreased the activity of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione levels in discrete regions of central nervous system. The results significantly (P < 0.05) demonstrated the effect of fluoride through exacerbated oxidative damage and disrupted antioxidant homeostasis, leading to altered neuronal integrity. The administration of antioxidants vitamin E, vitamin C, selenium and zinc produced a promising accost and timely intervention to the aggravated impairment during highly vulnerable early stage of life.     

Localisation of Sulphated Glycoconjugates during Hyaline Layer Formation in Rat Molars by Ultrastructural Cytochemistry

In order to study the presence of sulphated glycoconjugates in the first mineralised layer juxtaposed to the root dentine (the hyaline layer), we have examined the early stages of molar root development by ultrastructural cytochemistry using Cuprolinic Blue combined with enzymatic pretreatment. Upper molars from 10 to 13 day-old Wistar rats were fixed in 2.5% glutaraldehyde containing 0.05% Cuprolinic Blue in 25 mM sodium acetate, pH 5.6, containing 0.3 M MgCl2. Some specimens were previously treated with heparitinase or chondroitinase ABC. Our results showed sulphated glycoconjugate--Cuprolinic Blue complexes that appeared as electron opaque ribbon-like deposits in the unmineralised hyaline layer. Few complexes were detected adjacent to the dentinal surface. These complexes were removed by heparitinase, indicating that they contained heparan sulphate chains. In contrast, the complexes found in unmineralised cementum and root dentine were removed by chondroitinase, indicating that they contained chondroitin or dermatan sulphate chains. The complexes decreased after the initiation of mineralisation of hyaline layer and root dentine and they were no longer present in stages of fully mineralisation. We conclude that the hyaline layer only contains sulphated glycoconjugates prior to mineralisation, and that they may play a role in the regulation of the mineralisation.