Gamma knife radiosurgery in patients with Nelson's syndrome.

PURPOSE: Nelson's syndrome (NS) is a long-term complication of bilateral adrenalectomy in patients with Cushing's disease. The best therapeutic strategy in NS has not been well defined. Gamma knife radiosurgery (GKRS) is very effective to stop the growth of the pituitary adenoma, which is the main goal of the treatment of patients with NS. We report the largest series of patients with NS treated by GKRS at a single center. METHODS: The study was an observational, retrospective analysis of 28 consecutive patients with NS treated by GKRS in our department between 1995 and 2019. All patients had a growing ACTH-secreting pituitary adenoma. The main outcome of the study was to assess by the Kaplan-Meier method the risk of tumor progression after GKRS. RESULTS: The median follow-up after GKRS treatment was 98 months (IQR 61-155 months, range 7-250 months). Two patients (7.1%) had a recurrence of disease during follow-up. The 10-year progression-free survival was 91.7% (95% CI 80.5-100%). No patient had deterioration of visual function or oculomotor function after GKRS. New onset of hypogonadism and hypothyroidism occurred in 18.8% and 14.3% of the patients at risk. CONCLUSION: Our study confirms that GKRS may stop the tumor growth in the majority of patients with NS, even though very aggressive adenomas may ultimately escape this treatment. Safety of GKRS was good in our experience, but due attention must be paid to planning the distribution of radiation to critical structures, especially in patients previously treated by radiation.

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.

Glandular odontogenic cyst. A retrospective clinical, radiographic and histological study / Quiste odontogénico glandular. Estudio retrospectivo clínico-radiográfico e histológico

El quiste odontogénico glandular (QOG) foe recientemente descrito en base a un escaso número de casos. El propósito del presente trabajo fue tratar de ampliar su caracterización, analizando una serie do casos reunidos en un único Centro Diagnóstico. Para ello se realizó una búsqueda retrospectiva en el Laboratorio de Patología Quirúrgica, Cátedra de Anatomía Patológica, Facultad de Odontología Universidad de Buenos Aires, durante el período 1975-1998. Se revisaron todos los casos correspondientes a quistes odontogénicos embrionarios, seleccionando aquellos sin diagnóstico histopatológico definido y los carcinomas mucoepidermoides centrales. Los mismos se estudiaron microscópicamente y se separaron 10 casos quo reunían Ins caracterfsticas histológicas descritas par la OMS para los QOG. Se analizaron los datos clínicos de sexo, edad, localización, imagen radiográfica, diagnóstico clínico, tratamiento presuntivo y evolución. Esta serie mostró datos equivalentes a los previamente comunicados en alguno de los parámetros analizados, y una marcada diferencia en la distribución por sexos e imágenes radiográficas (AU)

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.

Impairment of molar tooth eruption caused by x-radiation.

The effect of x-radiation on erupting molars is presented. New born, 5 day old Wistar rats were locally irradiated in the molar area with doses of 20 Gy. They were killed in two groups, 30 and 60 days postirradiation respectively. Two other groups of non irradiated, age matched rats were killed at the given times. In addition a control group of 5 day old animals was also studied. Radiographic and histologic studies were performed. Odontoblastic atrophy, odontodysplasia, rootless formation, and ankylosis of tooth to bone by osteodentin formation with the resulting lack of tooth eruption were observed. The relation between the histologic alterations and tooth eruption is discussed.

Bone growth is impaired by uranium intoxication.

Acute and chronic uranium intoxication leads to the inhibition of bone formation and impaired bone modeling and remodeling. As these are processes directly involved in bone growth the aim of this paper is to present a biometric study of bone growth--tibiae and mandibles of rats intoxicated with uranium. Wistar ratios weighing 60-80 g were used as follows, a) one intraperitoneal injection (IPI, 2 mg/Kg of body weight)) of uranyl nitrate; b) 30 daily applications on the dorsal skin of aliquots of a mixture of U308, concentrated at 2% and at 4%--percutaneous absorption(PA)-. Tibia and mandible length were smaller in both experimental groups than in their respective controls. Some of the mandibular parameters were lower in intoxicated animals than their controls which in turn results in the alteration of the mandibular shape. We conclude that impairment in bone growth can be achieved by uranium intoxication.

Bone growth is impaired by uranium intoxication

Acute and chronic uranium intoxication leads to the inhibition of bone formation and impaired bone modeling and remodeling. As these are processes directly involved in bone growth the aim of this paper is to present a biometric study of bone growth--tibiae and mandibles of rats intoxicated with uranium. Wistar ratios weighing 60-80 g were used as follows, a) one intraperitoneal injection (IPI, 2 mg/Kg of body weight)) of uranyl nitrate; b) 30 daily applications on the dorsal skin of aliquots of a mixture of U308, concentrated at 2

and at 4

--percutaneous absorption(PA)-. Tibia and mandible length were smaller in both experimental groups than in their respective controls. Some of the mandibular parameters were lower in intoxicated animals than their controls which in turn results in the alteration of the mandibular shape. We conclude that impairment in bone growth can be achieved by uranium intoxication.

Bone growth is impaired by uranium intoxication.

Acute and chronic uranium intoxication leads to the inhibition of bone formation and impaired bone modeling and remodeling. As these are processes directly involved in bone growth the aim of this paper is to present a biometric study of bone growth--tibiae and mandibles of rats intoxicated with uranium. Wistar ratios weighing 60-80 g were used as follows, a) one intraperitoneal injection (IPI, 2 mg/Kg of body weight)) of uranyl nitrate; b) 30 daily applications on the dorsal skin of aliquots of a mixture of U308, concentrated at 2

and at 4

--percutaneous absorption(PA)-. Tibia and mandible length were smaller in both experimental groups than in their respective controls. Some of the mandibular parameters were lower in intoxicated animals than their controls which in turn results in the alteration of the mandibular shape. We conclude that impairment in bone growth can be achieved by uranium intoxication.

Structure-activity relationships in prazosin-related compounds. 2. Role of the piperazine ring on alpha-blocking activity.

Several prazosin-related compounds have been synthesized and evaluated for their blocking activity toward alpha-adrenoreceptors. The structural modification performed on the prazosin structure included the replacement of the piperazine ring with 2,3-dialkylpiperazine or 1,2-cyclohexanediamine moieties to characterize a lipophilic binding pocket in the alpha 1-adrenoreceptor surface. Cyclohexanediamine derivatives 3-6 were almost devoid of potency and selectivity, whereas dialkylpiperazine compounds 7-14 showed high affinity and selectivity toward alpha 1-adrenoreceptors. The cis derivative 13 (cyclazosin) was the most potent and selective with an alpha 1/alpha 2 selectivity ratio value of 7800. The particular trend of antagonist activity within cis/trans stereoisomeric compounds not only supports the presence of a lipophilic binding area on alpha 1-adrenoreceptor surface but also suggests that the lipophilic pocket is endowed with a well-defined size and spatial orientation. The most active compound of the series, 13, was tested also in vivo for antihypertensive activity on spontaneously hypertensive rats. It showed an interesting long-lasting hypotensive effect, very similar to that of doxazosin, which was statistically significant 12 h after oral administration.

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.

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.

Mandibular growth and tooth eruption after localized x-radiation.

The effect of localized x-radiation on the growth of mandibular bone and molar eruption was evaluated by morphometric methods. A dose of 20 Gy of x-radiation was given to the molar zone of growing rats. The animals were then killed in groups at 30 and 60 days postirradiation. Two groups of nonirradiated, age-matched rats were used as controls. Parameters related to molar eruption, mandibular length, and mandibular height were measured on lateral radiographs. The results obtained showed that the values of the biometric parameters were lower in experimental than in control animals. Odontoblastic atrophy, alveolodentary ankylosis, and meager or no root formation were the most conspicuous histologic findings. Osteodentin was found between canaliculary dentin and bone in cases of ankylosis. The morphometric data presented confirm the probability of alterations in mandibular growth and tooth eruption following x-radiation and suggest that this be considered in planning radiotherapy in children.

Methoctramine-related polymethylene tetraamines. 4. Chirality effect on M2 muscarinic receptor blocking activity.

Chiral methoctramine-related compounds (3 and 4), bearing two asymmetric atoms in the terminal benzylic moieties, were synthesized and evaluated for their blocking activity on M2 and M3 muscarinic receptors of guinea pig left atrium and ileum, respectively. It turned out that insertion of these chiral centers in methoctramine structure is ineffective in the ileum whereas it produces a significant decrease in potency in the atrium when compared to methoctramine (1). Furthermore, the enantiomers of 3 and 4 did not display significant enantioselectivity at both M2 and M3 muscarinic receptors.

Structure-activity relationships in 1,4-benzodioxan-related compounds. 2. Role of the amine function on alpha-adrenoreceptor blocking activity.

Several WB4101 (1)-related compounds were synthesized. Their alpha-adrenoreceptor blocking properties were evaluated in order to understand the kind of interaction occurring between the amine function of (1)-related compounds and the alpha-adrenoreceptor anionic site. The results suggest that a charge reinforced hydrogen bond rather than an ion pairing might play a most important role in receptor binding.