Comparative expression of cyclooxygenase 2 and Ki67 in amelanotic and conventional oral melanomas.

BACKGROUND: Oral melanomas have some histopathological resemblance with its cutaneous counterpart; however, an aggressive behavior is more common in tumors that occur in the oral cavity. Several markers have been suggested as indicative of tumoral progression and aggressiveness, such as cyclooxygenase 2 (COX-2) and Ki67. MATERIAL AND METHODS: In this study, we have compared the expression of COX-2 and Ki67 in a series of amelanotic (n=7) and melanotic oral melanomas (n=22). The cases were selected from 4 pathology laboratories and submitted to the immunohistochemical (IHC) reactions. We analyzed the IHC staining based on a qualitative - using visual scores; and a computer-assisted method (quantitative) using scanned slides and software for digital analysis. RESULTS: COX-2 was expressed in all oral melanomas; however, its intensity was significantly higher in the amelanotic ones (P<0.001). Similarly, a high Ki67-positivity index was observed in the amelanotic than melanotic ones (P<0.001). CONCLUSIONS: Based on these results, we suggest that amelanotic oral melanomas have marked pro-inflammatory and high-proliferative phenotype, justifying their more aggressive behavior compared with the melanotic ones.

Dental developmental alterations in patients with dilacerated teeth.

BACKGROUND: The aim of this study was to record and analyze all DDAs associated to dilacerated teeth in patients attending the clinics of the Postgraduate Division, Facultad de Odontología, UNAM in Mexico City. MATERIAL AND METHODS: Orthopantomograms from all patients seeking for stomatological attention in our institution were reviewed and those cases of dilaceration were separated. Age, gender, diagnosis, location, involved teeth and associated DDAs were recorded and analyzed. RESULTS: From 6,340 patients, 99 (1.6%) harbored 125 dilacerated teeth. Of them, 45 (45.5%) showed one or more DDAs. The most frequently detected DDAs were hypodontia, enamel pearls, taurodontism and microdontia. CONCLUSIONS: 45.5% is a very high proportion of DDAs in patients with dilacerated roots. Findings from this study strongly suggest that patients with dilacerated teeth should be carefully screened since many of them could present other DDAs. Simultaneous occurrence of dilaceration and DDAs suggests synchronic developmental defects during dental growth.

In vitro effect of sodium fluoride on antioxidative enzymes and apoptosis during murine odontogenesis.

Excessive fluoride ingestion has been identified as a risk factor for fluorosis and oxidative stress. The oxidative stress results from the loss of equilibrium between oxidative and antioxidative mechanisms that can produce kinase activation, mitochondrial disturbance and DNA fragmentation, resulting in apoptosis. Actually many people are exposed to no-adverted fluoride consumption in acute or chronic way. The aim of this study was to determine the effect of sodium fluoride on first molar germ in relation to its effect on antioxidative enzymes immunoexpression and apoptosis. Thirty first molar germs from 1-day-old Balb/c mice were cultured for 24 h with sodium fluoride (0 mM, 1 mM and 5 mM). Immunoexpression determination of CuZnSod, MnSod, catalase, Bax, Bid, caspase 8, caspase 9, caspase 3 and TUNEL assay were performed. Cellular disorganization in ameloblast and odontoblast-papilla zones was observed. CuZnSod and MnSod immunoexpression decrease in experimental groups. Caspase 8, caspase 3, Bax, Bid increase expression and more TUNEL positive cells in both experimental groups than control, suggest that apoptosis induced by fluoride is related to oxidative stress due to reduction of the enzymatic antioxidant.

Fluoride content in bottled waters, juices and carbonated soft drinks in Mexico City, Mexico.

OBJECTIVE: The objective of this study was to analyse 283 samples of soft drinks available in the metropolitan market of Mexico City, Mexico: 105 juices, 101 nectars, 57 carbonated drinks and 20 bottled waters. MATERIALS AND METHODS: Samples of the beverages were analysed using an Orion 720A potentiometer and an Orion 9609BN F ion-specific electrode. RESULTS: Fluoride concentration in the above-mentioned products ranged from 0.07 to 1.42 p.p.m. It was found that fluoride concentrations varied according to the brand, flavour and presentation of the product. The highest mean concentration of fluoride was found in the juices and cola drinks (0.67 +/- 0.38 and 0.49 +/- 0.41 p.p.m., respectively). The mean fluoride concentration for carbonated drinks was 0.43 +/- 0.36 p.p.m. Bottled waters had a fluoride concentration of 0.21 +/- 0.08 p.p.m. CONCLUSIONS: The findings suggest that fluoride ingested through bottled drinks represents an important part of the total fluoride ingested by the population. In view of the wide variation of fluoride concentration in the tested products, it is necessary to implement regulatory guidelines for controlling its concentration in order to prevent dental fluorosis.

Lead levels in primary teeth of children living in Mexico City.

OBJECTIVE: The aim of this study was to discover the lead concentration in primary teeth extracted in the peripheral clinics of the Faculty of Dentistry, UNAM (Mexico City). DESIGN: One hundred healthy primary teeth were collected from 2 to 13-year-old children (52 girls and 48 boys). Sixty-six were maxillary teeth and 34 were mandibular teeth. Lead concentrations were measured by Graphite Furnace Atomic Absorption Spectrophotometry. RESULTS: Our results indicate that lead concentration in the 10-13-year-old group (7.7 micro g/g(-1)) was higher than in the other groups. Geometric mean lead concentration was higher in girls than in boys (7.3 micro g/g(-1) and 6.3 micro g/g(-1), respectively). Maxillary teeth had higher lead concentrations than mandibular teeth and primary canines showed the highest mean lead concentration followed by incisors and molars. Teeth from children living in the south-east area (which according to the Mexico City's Pollution Center data is the more polluted area), presented the highest lead concentration but no statistically significant difference was found among teeth from the different areas. CONCLUSIONS: Our results suggest that age, gender and place of residence are not related to the lead concentration in human primary teeth. This fact seems to indicate the ubiquitous presence of lead in the whole atmosphere of Mexico City and suggests that zones of residence do not appear to influence tooth lead concentration.

Clinico-pathologic study of odontogenic cysts in a Mexican sample population.

BACKGROUND: Odontogenic cysts are uncommon lesions that frequently behave agressively and attain a large size. Unfortunately, information on the relative incidence of these cysts from different populations is not abundant. In Mexico, for example, only a few examples have been reported. The aim of this study was to ascertain the frequency of odontogenic cysts in a Mexican sample and to compare these data with previously reported studies from other countries. METHODS: The files of the Oral and Maxillofacial Pathology Diagnosis Service at the School of Dentistry at the Universidad Nacional Autónoma de México (UNAM) were reviewed and all accessions of odontogenic cysts were listed. Clinical and radiographic data were recorded and microscopic slides evaluated according to the most recent World Health Organization (WHO) classification (1992). RESULTS: Three hundred and four cases of odontogenic cysts (55.9% male predominance) were found. The most frequent odontogenic cysts were the following: periapical cyst (38. 8%); dentigerous cyst (35.5%), and odontogenic keratocyst (18.8%). Periapical cyst was more frequent in females, and maxillary anterior teeth were most commonly involved. Dentigerous cysts appeared in males at a rate of 64.8%, this cyst found more frequently between the 1st and 2nd decades of life and in the molar zone. Odontogenic keratocyst was more frequent in males (59.6%), between the 2nd and 4th decades of life and more common in the molar zone. CONCLUSIONS: More than 50% of the sample were aggressive cysts (dentigerous and keratocyst). Our results suggest that Mexican patients develop aggressive odontogenic cysts more commonly than other populations. Our figures point to the need for a precise diagnosis in order to institute the correct surgical procedure, prevent recurrence, and forestall more extensive tissue destruction.

[Fluorosis in primary dentition in a region with endemic water fluoride]. / Fluorosis en dentición temporal en un área con hidrofluorosis endémica.

OBJECTIVE: The aim of the present study was to estimate the prevalence of dental fluorosis in primary dentition of a San Luis Potosi children population, and its association to fluoride concentration in drinking water and urine. An additional objective was, to develop, validate, and test a specific index for dental fluorosis in primary dentition. MATERIAL AND METHODS: From May 1997, to January 1999, we conducted a cross-sectional study to assess the prevalence of dental fluorosis in primary dentition. Study subjects were 100 children aged 3-6 years, selected at random from three kindergartens in three risk areas of San Luis Potosi. The specific index of dental fluorosis for primary dentition (Dental Fluorosis for Primary Dentition Index--DFPDI) was validated by estimating fluoride concentrations in enamel of teeth with and without dental fluorosis. The Kruskal-Wallis test was used to assess the association between fluoride concentrations in drinking water and urine, with dental fluorosis; the association between risk area and dental fluorosis was assessed with the Mantel-Haenszel chi 2 test. RESULTS: The prevalence of dental fluorosis in primary dentition was 78%; primary molars were most affected in both maxillae and the predominant color was a non-glossy white appearance. We found a strong direct correlation (r = 0.93) between fluoride concentrations in primary teeth and the DFPDI. Associations were found between fluoride concentrations of drinking water and urine, with dental fluorosis (Kruskal-Wallis p = 0.00001), and between risk area and dental fluorosis (Mantel-Haenszel chi 2 p = 0.00001). CONCLUSIONS: DFPDI allowed adequate identification and grading of dental fluorosis in primary dentition. It is important to detect the initial toxic effects of fluoride exposure to predict dental fluorosis in permanent dentition and skeletal fluorosis.

[Bottled beverages as additional sources of exposure to fluoride]. / Bebidas embotelladas como fuentes adicionales de exposición a flúor.

OBJECTIVE: To evaluate and to report the concentration of floride in soft drinks and juices consumed in San Luis Potosi, S.L.P., Mexico, and its implications as a risk factor for developing dental fluorosis. MATERIAL AND METHODS: The contents of some products from 2 main national companies and 2 other local companies were studied. The samples were collected from 10 different batches in the case of the soft drinks, and from 5 batches in the case of the juices, with 3 samples per batch, during 3 months. The ion selective electrode method was used to determine the concentration of fluoride. RESULTS: Soft drinks from 2 main national companies showed high fluoride concentrations that were statistically significant between groups (p < 0.05). Fluoride levels of products from local and national companies also showed differences that were statistically significant between groups (p < 0.05). All natural juices tested showed high fluoride concentrations. CONCLUSIONS: Most soft drinks and juices consumed in SLP had high fluoride levels above Mexican regulations (0.7 ppm) and could be a substantial risk factor for developing dental fluorosis.

Gingival salivary gland choristoma. A case report.

Gingival salivary gland choristoma is an extremely rare disturbance of glandular development. A review of the literature disclosed only 5 reported cases of this entity and 7 gingival salivary gland tumors or alterations. We present a case of this condition present in a 43-year-old female patient, which was found while reviewing casts for the design of a prosthetic appliance. This case suggests that embryonal pluripotentiality of gingival epithelial cells is retained and that development of salivary glands in gingival tissue is feasible. An additional discussion about its histogenesis is presented.

Effects of maternal ethanol intake on second alcoholic generation murine skull and mandibular size.

BACKGROUND: Fetal Alcohol Syndrome (FAS) represents an important array of abnormalities in the development of offspring born of alcoholic mothers. This investigation used a murine Balb/cJ model to investigate the effects of maternal ethanol intake on craniomandibular and long bone development. METHODS: Experimental 8-week-old female mice (daughters of alcoholic female mice) drank an ethanol solution increasing from 1-20%, and 6 weeks later were mated with non-alcoholic males. The control group consisted of normal Balb/cJ male and female mice that drank water without ethanol. Alcohol intake was suspended at delivery, and 90 puppies (second alcoholic generation) were sacrificed at 14.5, 21.5 and 28.5 postnatal days. Measurements of craniofacial structures and long bones were done blindly by means of a standardized method. RESULTS: Our results indicate that maternal ethanol intake had a significant deleterious effect on craniofacial development, since litters from alcoholic mothers had smaller dimensions compared with non-alcoholic control puppies. No statistically significant results were obtained from long bone measurements. CONCLUSIONS: Even though the mechanism that accounts for these changes is not fully explained by our results, we hypothesize that the reduction of cephalometric dimensions found in this study could be a manifestation of disorganized neural and mesenchymal development.

Immunoexpression of epidermal growth factor in odontogenesis of the offspring of alcoholic mice.

Several forms of cell perturbation have been associated with ethanol ingestion. Fetal alcohol syndrome (FAS) as well as diminished maxillofacial development and inhibition of cell regeneration in vitro and in vivo have been described. Epidermal growth factor (EGF) stimulates maxillofacial growth, DNA synthesis, and it is a potent mitogen for a number of various cell types. EGF exerts its effects on cells through binding to a specific cell surface receptor which leads to activation of a thyrosine kinase in the intracellular part of the receptor. The inhibitory effect of alcohol on EGF in the mouse dental follicle was studied in the offspring of alcoholic mothers using immunocytochemistry. Adult female mice were given 22% alcohol in their drinking water and fed a pelleted diet before and during pregnancy. Maternal blood alcohol levels were 262 +/- 1.3 mg/100 ml on gestation day 12.5. The offspring of the alcoholic and control mice were sacrificed on postnatal day 1.5, their mandibles were dissected, weighed and processed by routine immunocytochemistry with the following results. 1) Significant differences were found in mandible weight p < 0.01 after parturition. 2) The tooth germs in the offspring of ethanol treated mice were morphometrically smaller than those of control littermates. 3) Immunoexpression of EGF in the mandibular first molar of the control group was strong and homogeneous while in the experimental group the expression was light and heterogeneous. It is concluded that maternal alcoholism reduces EGF in the offspring.

Interleucina-2: una terapia alternativa en cáncer / Interleukin-2: an alternative therapy for cancer

Recientemente, se ha demostrado que la manifestación de inmunidad antitumoral resulta de las interacciones entre varias poblaciones celulares del sistema inmune. La inmunoterapia con interleucina-2 (IL-2) y células destructoras de linfocinas activadas generadas por linfocitos análogos ha producido regresiones significativas en tumore de pacientes con cáncer avanzado. El efecto mitogénico de la IL-2 en linfocitos T citolíticos de tumores-reactivos (CTL), destructores naturales y LAK puede incrementar el potencial de defensa en la expansión de tumores. A diferencia del tratamiento sistémico, la administración de IL-2 en la vecindad del tumor puede ofrecer ciertas ventajas, tales como: uso de dosis bajas y menos anticuerpos anti IL-2 y proveer un cambio de confrontación mucho mejor con inhibidores IL-2 y mecanismos de retroalimentación, los cuales podrán limitar sustancialmente los posibles efectos terapéuticos de la IL-2 en pacientes con tumores

In vivo diagnostic assessment of dentinal caries utilizing acid red and povidone-iodine dyes.

In order to compare the clinical utilization of diagnostic dyes to identify carious dentin, the present in vivo study compared two caries-detector dyes, acid red (1% acid red in propylene glycol wt/wt) and povidone-iodine (8% povidone-iodine in water wt/vol). A total of 221 cavities prepared by 19 senior dental students under the supervision of two teachers at the Universidad Nacional Autónoma de México Dental School were used. Dyes were applied double-blind under standardized conditions to at least two teeth of the same patient. Data were analyzed using the Mantel-Haenszel chi-square test and a test of proportions. Results showed that molars or premolars did not appear to be positively stained more frequently by one dye or another. Also, 36.7% of teeth tested positive to either one of the two dyes. Prudent utilization of either acid red or povidone-iodine appeared to be equally useful in assisting clinical decisions concerning cavity size while restoring dentinal lesions. However, povidone-iodine may be preferred in clinical settings where acid red is expensive and/or difficult to obtain. Further research is necessary to establish accurately the mechanism of staining by povidone-iodine.