MALT lymphoma in labial salivary gland biopsy from Sjögren syndrome: importance of follow-up in early detection.

Mucosa-associated lymphoid tissue (MALT) lymphomas are known to occur in Sjögren syndrome (SS) patients, but reported cases in labial salivary glands (LSG) are rare. We report a case of 60-year-old female patient with SS who developed MALT lymphoma in the labial salivary glands during a 2-year time interval when she was participating in the Sjögren's International Clinical Collaborative Alliance, an ongoing longitudinal multisite observational study funded by the National Institutes of Health of the United States. At follow-up exam, LSG biopsy showed atypical diffuse infiltration by mononuclear cells of variable size and atypical nuclei affecting the whole specimen with destruction of glandular architecture, leading to a diagnosis of B-cell MALT lymphoma. Computerized tomography and bone marrow biopsy failed to show additional evidence of disease. Clinical, serologic, ocular, histologic and immunohistochemical findings are presented. A "watch and wait" policy was adopted with regular examinations.

Granuloma gigantocelular central del maxilar inferior: Presentación de un caso pediátrico / Giant cell granuloma of the lower jaw: Description of a pediatric case

El granuloma gigantocelular central (GGCC), es una lesión tumoral o seudotumoral, infrecuente de los huesos de la cabeza y cuello, que afecta más frecuentemente los maxilares. Su etiología y patogenia son poco conocidas, sus características histológicas son benignas y su comportamiento biológico puede ser agresivo localmente. Presentamos el caso de un niño de 6 años con esta afección y realizamos una revisión de la entidad y sus diagnósticos diferenciales con otras lesiones de los maxilares.

Giant Cell Granuloma (GCG) is an uncommon condition affecting the bones of the head and neck. The ethiology and pathophysiology are not completely understood. The histlogic characteristics of GCG are benign, but its biologic behavior could locally aggressive. We describe the case of a 6 year-old boy with GCG and performed a review of the entity ant their differential diagnosis with other lesions of the maxillary bones.

Malignant transformation in odontogenic keratocysts. Case report.

Squamous cell carcinoma arising in the epithelial lining of an odontogenic keratocyst is a rare finding. Up to now, only 12 cases have been reported in the literature. The present work reports a new case diagnosed in a 70 year old man. The clinical, radiographic, and histopathological findings and the treatment are described.

Queratoquiste odontogénico con transformación carcinomatosa. Presentación de un caso / Malignant transformation in odontogenic keratocysts. Case report

El desarrollo de un carcinoma de células escamosas a partir del revestimiento epitelial de un queratoquiste odontogénico es poco común. Hasta el momento sólo 12 casos han sido documentados en la literatura internacional. Se presenta un nuevo caso en un varón de 70 años de edad describiendo los hallazgos clínicos, radiográficos y anatomopatológicos; y se comenta el tratamiento realizado (AU)

Use of correction procedures in ploidy analysis of oral carcinomas.

Ploidy analysis is an aid in the diagnosis and evaluation of prognosis of tumors. Image analysis is a relatively simple technique to assess ploidy that can be carried out with accessible equipment. However, it requires the use of accurate technical procedures to avoid methodological errors that may bias the measurements. We previously developed two procedures that are simple to apply in routine work and serve to correct the errors derived from the measurement of large nuclei that are not fully contained in the thickness of the section and those derived from non-specific background readings. In the present study we applied these corrections to the retrospective ploidy analysis of a series of 67 patients with oral carcinoma with a follow-up time of 18 months. Thirty-four patients were alive at the end of the study, 33 were deceased. The ploidy values and the malignancy indices corresponding to the deceased and live patients with TNM stage III and IV carcinomas at the time of biopsy were significantly different. There were no significant differences in ploidy values between live and deceased patients with TNM stage I and II at the time of biopsy. The corrections improved the sensitivity of the method and thus the statistical significance of the data. These data suggest that the method proposed may be of use to estimate lesion evolution, in particular in patients with advanced oral squamous cell carcinomas.

Use of correction procedures in ploidy analysis of oral carcinomas.

Ploidy analysis is an aid in the diagnosis and evaluation of prognosis of tumors. Image analysis is a relatively simple technique to assess ploidy that can be carried out with accessible equipment. However, it requires the use of accurate technical procedures to avoid methodological errors that may bias the measurements. We previously developed two procedures that are simple to apply in routine work and serve to correct the errors derived from the measurement of large nuclei that are not fully contained in the thickness of the section and those derived from non-specific background readings. In the present study we applied these corrections to the retrospective ploidy analysis of a series of 67 patients with oral carcinoma with a follow-up time of 18 months. Thirty-four patients were alive at the end of the study, 33 were deceased. The ploidy values and the malignancy indices corresponding to the deceased and live patients with TNM stage III and IV carcinomas at the time of biopsy were significantly different. There were no significant differences in ploidy values between live and deceased patients with TNM stage I and II at the time of biopsy. The corrections improved the sensitivity of the method and thus the statistical significance of the data. These data suggest that the method proposed may be of use to estimate lesion evolution, in particular in patients with advanced oral squamous cell carcinomas.

Use of correction procedures in ploidy analysis of oral carcinomas

Ploidy analysis is an aid in the diagnosis and evaluation of prognosis of tumors. Image analysis is a relatively simple technique to assess ploidy that can be carried out with accessible equipment. However, it requires the use of accurate technical procedures to avoid methodological errors that may bias the measurements. We previously developed two procedures that are simple to apply in routine work and serve to correct the errors derived from the measurement of large nuclei that are not fully contained in the thickness of the section and those derived from non-specific background readings. In the present study we applied these corrections to the retrospective ploidy analysis of a series of 67 patients with oral carcinoma with a follow-up time of 18 months. Thirty-four patients were alive at the end of the study, 33 were deceased. The ploidy values and the malignancy indices corresponding to the deceased and live patients with TNM stage III and IV carcinomas at the time of biopsy were significantly different. There were no significant differences in ploidy values between live and deceased patients with TNM stage I and II at the time of biopsy. The corrections improved the sensitivity of the method and thus the statistical significance of the data. These data suggest that the method proposed may be of use to estimate lesion evolution, in particular in patients with advanced oral squamous cell carcinomas.

Separation and identification of volatile components in the fermentation broth of Trichoderma atroviride by solid-phase extraction and gas chromatography-mass spectrometry.

A preseparated fermentation broth of Trichoderma atroviride strain 11 is analyzed by gas chromatography followed by mass-spectral detection using a Finnigan MAT GCQ apparatus. After preseparation in a C18 and a silica gel column, nineteen pyrone and dioxolane derivatives and two aliphatic esters are obtained, respectively. Among these, the four dioxolane derivatives have not been identified previously. The main component is found to be 5,5'-dimethyl-2H-pyran-2-on. The relative standard deviation for the determination of the retention time and the peak area (measured in ion counts) is 0.1% and 4.5%, respectively.

Mechanism of volatile compound production during storage of sunflower Oil.

Volatile compounds formed in the course of the thermal decomposition of hydroperoxides during storage of sunflower oil were analyzed by headspace solid-phase microextraction sampling followed by gas chromatographic separation and mass spectral detection. The determining role of alkoxyl radicals in the process has been proven by electron spin resonance spectroscopic measurements. On the basis of analytical results, the reaction networks and mechanisms were constructed by computer modeling to describe the formation of volatile products of radical decomposition of hydroperoxides. We established that off-flavor aliphatic aldehydes are originated from only the alkoxyl radicals derived from trigliceride of linoleic acid. To find a specific additive, which redirects the formation of these radicals toward production of more stable species, is suggested.

Principal component analysis of measured quantities during degradation of hydroperoxides in oxidized vegetable oils.

Decomposition of hydroperoxides in sunflower oil under strictly oxygen-free conditions was followed by measuring peroxide values against time, absorbance values at 232 and 268 nm, para-anisidine values, and by quantitative analyses of volatile products using various additives. The results were arranged in a matrix form and subjected to principal component analysis. Three principal components explained 89-97% of the total variance in the data. The measured quantities and the effect of additives were closely related. Characteristic plots showed similarities among the measured quantities (loading plots) and among the additives (score plots). Initial decomposition rate of hydroperoxides and the amount of volatile products formed were similar to each other. The outliers, the absorbance values, were similar to each other but carried independent information from the other quantities. Para-anisidine value (PAV) was a unique parameter. Since PAV behaved differently during the course of hydroperoxide degradation, it served as a kinetic indicator. Most additives were similar in their effects on the mentioned quantities, but two outliers were also observed. Rotation of the principal component axes did not change the dominant patterns observed. The investigations clearly showed which variables were worth measuring to evaluate different additives.

Physico-chemical modeling of the role of free radicals in photodynamic therapy. IV. Quantitative aspects of photodynamic effects on free radicals generated in cell cultures.

Production and the mechanism of the interactions of free radicals generated by stimulated macrophages in the presence of luminol and a free radical inhibitor was investigated to determine the possibility of using luminol-dependent chemiluminescence for studying photodynamic effects in biology. Earlier measurements have been revisited and additional experiments performed indicating that oxidation products of luminol neither inhibit the in vitro formation of radicals nor quench CL. Simulation based on the mechanism suggested revealed that the likely value for the rate constant of the primary step between luminol and superoxide anion radicals producing luminol radicals is 5x10(2)-1x10(3) M-1s-1. It has been established that the ratio of the concentration of radicals generated by the biological system to that formed by oxidation of luminol exceeds 10(3); that is, the contribution of the latter is negligible and the system is appropriate to measure quantitatively the effect of excited photosensitizers on free radicals.

Scientific presentations and publications on odontological research in Argentina.

The results of odontological research which are presented at the annual meetings of the Argentine Division of the International Association for Dental Research (A.D.I.A.D.R.) are proof of the scientific production of this country in this area. An analysis of the presentations allows for the quantitative evaluation of the activity of the area. A deeper appraisal of the reality of research, involves the analysis of quality and publication efficiency. A useful indicator is the relationship between the quantity of the presentations and subsequent publications (Publ./Pres. Ratio) in Journals with peer review. In 1990, the authorities of the Division presented an evaluation of the 10 previous years (Acta Odont. Latinoamer. 7(2):39-46, 1993). The current Board of Directors has considered timely to update that information. With this aim in mind the presentations at A.D.I.A.D.R. over the period 1990-1995 were considered. Employing the authors index of the A.D.I.A.D.R. meeting we searched for possible publications in Medline. The references were compared with the data from the presentations, disregarding those which had not been communicated previously in the Division. The data obtained were grouped according to Research Center and subject area. The Publ./Pres. Ratio was calculated. The time to publication and language of publication were considered. Of a total of 506 presentations, 61 were published, Ratio Publ./Pres. 1:8 (12%). Considering each Center individually the ratio was 1:6 for the University of Buenos Aires (UBA), 1:13 for the National University of Córdoba (UNC), 1:3 for the National University of La Plata (UNLP) and 1:2 for the National University of Rosario (UNR). There were no records of publications from the National Universities of Tucumán and of the North-East. The groups of investigation with greater quantity of presentations and better Publ./Pres. Ratio were Dental Mat./Restorative Dent./Endod. (ratio 1:8), Physiol./Pharmacol./Biochem. (Ratio 1:4) and Oral Pathol. (Ratio 1:4) of UBA, and Physiol./Pharmacol. (Ratio 1:1) of UNC. Most of the publications were in English (86%) and within 4 years of presentation. The current Publ./Pres. Ratios are similar to those communicated in 1990 in the area of the basic investigation and represent acceptable values. An increase in this proportion is expected in the future especially in the area of applied clinical research, since publication would imply prior peer review and thus qualitative evaluation of the work.

Desmoplastic and non-desmoplastic ameloblastoma: a comparative clinicopathological analysis.

OBJECTIVES: The aim of this study was to review a large series of ameloblastomas, accessioned during a period of 35 years in a single Oral Pathology Diagnostic Center, for the incidence of desmoplastic ameloblastoma (DA) and in order to analyze the clinical features of this unusual variant. MATERIALS AND METHODS: All cases diagnosed as ameloblastoma were reviewed and 14 were rediagnosed as DA. These cases were analyzed in terms of gender, patient age, location, clinical diagnosis, radiographic features and recurrence following treatment. Data from DA and non-desmoplastic ameloblastoma (NDA) were compared. RESULTS: The incidence of DA in this series was 8.8%. The mean age of NDA and DA were 39.1 and 38.8 years respectively, and a higher female prevalence was observed in the latter. The mandible was the most affected bone in both groups of tumors, but with a different regional distribution. Most NDA arose in the angle and ramus of the mandible, but the premolar/molar region was the preferential location for DA. The most common radiographic feature in DA was the osteolytic type, either monolocular or multilocular. Most of these cases were clinically diagnosed as ameloblastoma. According to follow-up data available, 21.4% of DA and 10.1% of NDA recurred. CONCLUSIONS: The results of this study do not support the hypothesis that DA should be a separate clinicopathological entity. It seems most likely that DA is another histologic variant of ameloblastoma.

Myxoma in childhood: an analysis of 10 cases.

PURPOSE: The object of this study was to present a series of myxoma in children and to evaluate possible differences between young and adults patients. MATERIALS AND METHODS: All tumors of patients under 16 years of age (10 cases), were separated from the 80 myxomas found in the Oral Pathology Laboratory, Faculty of Odontology, Buenos Aires University, and were analyzed in terms of clinical data, radiographic image, histopathology, treatment, and evolution. RESULTS: Myxoma in childhood represented 12.5% of the 80 cases in our series. The mean age was 11.6 years. Six patients were boys and four were girls. Both jaws were affected equally, predominantly in the premolar-molar region. Eighty percent of the tumors were larger than 2 cm. Only one case was clinically diagnosed as myxoma. Radiologically the most frequent image was unilocular with cortical expansion and tooth displacement. Histologically seven cases were diagnosed as myxoma and three as fibromyxoma. Treatment involved surgical resection in most cases. Two patients showed recurrence within the first year after surgery. CONCLUSIONS: The frequency of myxoma in childhood may be higher than that of other aggressive odontogenic tumors, although some literature refers to this tumor as very uncommon in children. Clinically this tumor may not always be taken into account in the differential diagnosis of intraosseous radiolucencies in young patients. The histologic appearance is similar in young and adult patients, but myxoma in children may be larger. It was not possible to correlate the histologic type of myxoma and the age of the patients.

Scientific presentations and their publication. Experience over a 10-year period in the Argentine Division of the I.A.D.R.

At present the "Impact Factor" developed by the Scientific Information Institute (Philadelphia), is an indicator of the quality of the journals in terms of the quality of the papers which are published. The results of odontological research which are presented and discussed at the annual meetings of the DAAIIO are proof of the quality and quantity of scientific production in this area in Argentina. Presentations are undoubtedly numerous. However, their diffusion and qualitative evaluation are of utmost importance. One way to estimate these parameters would be to monitor the ratio between number of presentations and their publication as full papers in journals with a system of referees (Ratio Publ./Pres.). With this aim in mind the presentations at DAAIIO over the 1980-1989 period were considered. Employing the author index of the DAAIIO meetings, we searched for possible publications in the Index Dental and the Index Medicus. The references were compared with the results presented to disregard publications which had not been previously presented at DAAIIO meetings. The data obtained were grouped according to subject area and Research Center. A total of 747 presentations led to 94 publications, the Publ./Pres. Ratio being 1/8 (12.5%). The ratio for each research center was the following: Univ. Buenos Aires 1/7; Natl. Univ. La Plata 1/8; Natl. Univ. Córdoba 1/15. The research groups with the highest publication ratios were Dent. Mat., Natl. Univ. La Plata 1/3; Clinical Pathol., Univ. Bs. As. 1/4; Oral Pathol., Univ. Bs. As. 1/4; Physiol. and Pharmacol., Univ. Bs. As. 1/4; Natl. Univ. Córdoba 1/7. The majority of the publications within 2 years of presentation were in English (69%). These results suggest that an acceptable number of presentations are published, particularly in the area of basic research. We should hope for an increase in the publication/presentation ratio in the future, particularly in the area of applied clinical research since publication would imply technical-scientific quality evaluation of the work by the experts who condition publication.

Scientific presentations and their publication. Experience over a 10-year period in the Argentine Division of the I.A.D.R.

At present the [quot ]Impact Factor[quot ] developed by the Scientific Information Institute (Philadelphia), is an indicator of the quality of the journals in terms of the quality of the papers which are published. The results of odontological research which are presented and discussed at the annual meetings of the DAAIIO are proof of the quality and quantity of scientific production in this area in Argentina. Presentations are undoubtedly numerous. However, their diffusion and qualitative evaluation are of utmost importance. One way to estimate these parameters would be to monitor the ratio between number of presentations and their publication as full papers in journals with a system of referees (Ratio Publ./Pres.). With this aim in mind the presentations at DAAIIO over the 1980-1989 period were considered. Employing the author index of the DAAIIO meetings, we searched for possible publications in the Index Dental and the Index Medicus. The references were compared with the results presented to disregard publications which had not been previously presented at DAAIIO meetings. The data obtained were grouped according to subject area and Research Center. A total of 747 presentations led to 94 publications, the Publ./Pres. Ratio being 1/8 (12.5

). The ratio for each research center was the following: Univ. Buenos Aires 1/7; Natl. Univ. La Plata 1/8; Natl. Univ. Córdoba 1/15. The research groups with the highest publication ratios were Dent. Mat., Natl. Univ. La Plata 1/3; Clinical Pathol., Univ. Bs. As. 1/4; Oral Pathol., Univ. Bs. As. 1/4; Physiol. and Pharmacol., Univ. Bs. As. 1/4; Natl. Univ. Córdoba 1/7. The majority of the publications within 2 years of presentation were in English (69

). These results suggest that an acceptable number of presentations are published, particularly in the area of basic research. We should hope for an increase in the publication/presentation ratio in the future, particularly in the area of applied clinical research since publication would imply technical-scientific quality evaluation of the work by the experts who condition publication.