Rosario Verduga

Effects of melatonin on the proliferation and differentiation of human neuroblastoma cells in culture

Since melatonin has direct inhibitory effects on some tumor cells in vitro, the aim of the present work was to study whether the growth and structural characteristics of the human neuroblastoma cell line SK-N-SH in vitro are influenced by this indoleamine. Concentrations of melatonin of 10(-9) and 10(-11) M significantly inhibited (P < 0.05) cell proliferation. Subphysiological (10(-13) M) or supraphysiological (10(-7) and 10(-5) M) concentrations of melatonin lacked this effect. After 8 days of exposure to melatonin (10(-9) M), cells showed significantly smaller cell and nuclear sizes than control cells. Melatonin-treated cells presented greater neurite outgrowth than control cells. These results support the hypothesis that melatonin, at physiological concentrations, exerts a direct antiproliferative effect on SK-N-SH cells, promoting the differentiation of neuroblastoma cells.

Cholinergic, serotonergic and catecholaminergic neurons are not affected in Ts65Dn mice.

TS65DN mice were developed as a model of Down syndrome (DS); they are trisomic for the distal segment of chromosome 16 (MMU16), which contains genes syntenic with some of the genes located on the critical region of human chromosome 21 (HSA21). Since behavioral and neurochemical disturbances have been observed in this animal model, it seemed interesting to perform an immunohistochemical characterization of the main cholinergic, catecholaminergic and serotonergic nuclei. However, when the brains of Ts65Dn mice were compared with those of control littermates, no differences were found either in the morphology of the neurons of the three systems or in the number of immunoreactive cells. The results indicate that these systems are not affected by the triplication of some of the genes present on chromosome 16.

Differences between the circadian system of two strains of senescence-accelerated mice (SAM).

The aim of this study was to look for morphological or functional differences between the circadian system of two substrains of Senescence Accelerated Mice (SAM): senescence-prone (SAMP8; average median survival time = 10.0 months) and senescence-resistant (SAMR1; average median survival time = 18.9 months). Neither the general structure nor the quantitative analysis of the number of VP-positive neurons in matched sections revealed differences between SAMP8 and SAMR1 mice. Under LD 12/12 photoperiod, all animals showed the typical pattern of wheel running activity with maximum activity in the first half of darkness period. The period of the locomotor activity in free running as well as the time course for synchronization after a 6 h phase delay of LD cycle were similar in both strains of SAM mice. However, SAMP8 animals reentrained significantly earlier (3.4 +/- 0.4 days) than SAMR1 (6.3 +/- 0.9 days) after a 6 h phase advance of LD cycle. We conclude that the circadian system of SAMP8 mice presents some functional differences with that of SAMR1, which could help to explain their different rate of ageing.

Neurons co-localizing calretinin immunoreactivity and reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) activity in the hippocampus and dentate gyrus of the rat

Co-localization of calretinin immunoreactivity and nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) activity was studied in the rat hippocampus and dentate gyrus. Neurons co-expressing both markers (CR/NADPH-d) were observed throughout the hippocampus and dentate gyrus. However, they were more abundant in the stratum pyramidale and radiatum of CA3, stratum pyramidale of CA1, and in the juxtagranular zone of the hilus. The NADPH-d activity appeared in 37% of the calretinin immunoreactive neurons in CA3, 42% in CA1, and 36% in the dentate gyrus, whereas calretinin immunoreactivity occurred in 41% of the NADPH-d positive neurons in the hippocampus, and 16% in the dentate gyrus. The morphology and location of the double marked cells could not be used as a characteristic of the co-localizing neurons. The heavily stained NADPH-d neurons occurring mainly in CA1 do not show calretinin immunoreactivity. NADPH-d fiber swellings could be observed in close apposition to calretinin immunoreactive neurons and dendrites, suggesting synaptic contacts. It has been reported that calretinin immunoreactivity and NADPH-d activity co-localize infrequently in other areas such as the neocortex, striatum, hypothalamus and tegmental nucleus. The relatively high proportion of double marked cells found in the hippocampus and dentate gyrus could be indicative of the importance of the CR/NADPH-d interneurons in the circuitries of these areas.

La estereología como herramienta de cuantificación del volumen y la atrofia cortical en el cerebro del anciano con demencia

Introduccion: la estereologia es un conjunto de metodos que permiten la estimacion insesgada y eficiente de cantidades geometricas definidas en estructuras arbitrarias. En particular, es una herramienta util en la cuantificacion de parametros morfometricos cerebrales en estudios de neuroimagen. Por tanto, la estereologia puede aportar una mayor objetividad en la evaluacion complementaria y diagnostica de ancianos con demencia, anadiendo datos cuantitativos a la evaluacion clinica. Objetivos y metodos: nuestro objetivo es ilustrar la estimacion del volumen cerebral y el area superficial de la corteza cerebral de un paciente anciano mediante procedimientos estereologicos cuantitativos asistidos por ordenador. Para estimar ambos parametros se utilizo un diseno vertical con una serie de secciones paralelas de Cavalieri con orientacion aleatoria y perpendiculares a un plano horizontal fijo. Las secciones se obtuvieron mediante resonancia magnetica nuclear. Sobre ellas se superpusieron sondas sistematicas (de puntos para el volumen y de cicloides para la superficie) mediante un software especial. Resultados: con objeto de explorar la variabilidad del error estadistico de las estimaciones, se utilizaron 5 o 10 secciones sistematicas combinadas con dos densidades de puntos de sonda en la relacion 1:4, de tal manera que el trabajo invertido vario en la relacion 1:2:4:8. Los cuatro estimadores obtenidos variaron entre 986 y 1.120 cm3. Por otra parte, para el area de la superficie pial los estimadores variaron entre 1.947 y 2.096 cm2, con cargas de trabajo variables en la relacion 1:2:2.3:4.6. Conclusiones: la estereologia es una herramienta sencilla y eficiente, capaz de proporcionar estimaciones objetivas, no sesgadas por diseno, del volumen y la superficie cerebral pial con un coste modesto. Ello puede contribuir a facilitar la evaluacion diagnostica, evolutiva y pronostica de pacientes ancianos con demencia.

A LARGE MOUTH ULCER, CAUSED BY A FERROUS SULPHATE TABLET IN DIRECT CONTACT WITH ORAL MUCOSA IN A PATIENT WITH SENILE DEMENTIA

loculation of lesions is not always characteristic. In both of our patients the predominant signs were confusion and functional decline. The classical findings were absent. As noted, our first patient was afebrile. Incidentally, both of these features (impaired functional status and absence of fever on admission) are among the major predictors of mortality in patients with bactcreniia.6 An interesting finding is the combination of thrombocytosis with left pleural effusion in our second patient. Ho et al.’ evaluated signs of SA in an intensive care unit and concluded that this coincidence in a septic patient is suspicious and SA should be ruled out. There have been reports of antibiotic treatment alone,*” percutaneous and splenotomy13 for successful management of SAY but splenectomy is still the most radical and most effective treatment and decreases dramatically the previously high mortality rate.3”4”5 We think that avoidance of major surgery and salvage of the spleen may be considered in an older patient, but only when saving the patient’s life can be assured. We propose a flexible approach to the management of SA in geriatric care. When diagnosed, the SA should be aspirated and cultured. If the patients condition allows and the abscess is unilocular, percutaneous drainage, followed by antibiotics may be carried out. If there is no quick response, or if there is clear evidence of multiple lesions, splenectomy should be performed. Any delay may be fatal.

Some Questions About Dementia and Tube Feedings.

To the Editor: We agree with the American Geriatrics Society Ethics Committee and Clinical Practice and Models of Care Committee in that careful hand feeding should be offered to all individuals with advanced dementia. However, people with dementia must have a feeding tube placed under certain circumstances (e.g., beliefs, family burdens, family-related responsibilities, nursing home characteristics, acute hospital settings). Sometimes, surprisingly, the main and only indication for placing a feeding tube is prevention of aspiration pneumonia. Taking this into consideration those circumstances, we disagree that difficulty eating and feeding is associated with poor prognosis over the short term. Although the short-term prognosis, accurate prognosis of survival in advanced dementia is elusive. In addition, the assertion that tube feeding is associated with agitation and greater use of physical and chemical restraints is not completely correct. The setting might be completely different for individuals with dementia with a nasoenteric tube and those with percutaneous gastrostomy (PEG). In the case of nasoenteric tube, behavioral disturbances appear in many individuals and it is therefore necessary to prescribe physical or chemical (e.g., neuroleptics, benzodiazepines) restraints. In a previous letter to this journal, we reported that individuals with advanced dementia and PEG tubes did not exhibit PEG-associated behavioral disturbances and did not need any physical or chemical restrain. Although advanced dementia is a serious burden for health systems, professionals, relatives, and the individuals themselves we must be aware of some opinions on this topic. The individual’s comfort must be the main goal, but is an untreated individual with pneumonia, fever, or eating problems comfortable? Finally, advanced dementia is usually a complicated condition with a long trajectory. To affirm that all individuals with dementia have a terminal illness and therefore that use of a PEG tube must be completely excluded in elderly adults with dementia is similar to the idea described in a famous children’s story: “Sentence first—verdict afterwards.”

The influence of age on supraoptic nucleus glial cells of the mouse

In 2-year-old mice, astrocytes of the supraoptic nucleus (SON) of the hypothalamus, placed in close contact with the meningeal covering contained concentric arrangements of cisterns in their cytoplasm called glial concentric bodies (GCBs). They are formed by a variable number of flattened cisterns without pores, and no anastomosis was observed between adjacent cisterns. Rough endoplasmic reticulum (RER) cisterns do not show continuity with fully developed GCBs, although a close continuity between RER cisterns and GCBs was present in images suggesting GCB formation. Concomitantly with the appearance of GCBs, ventral neurosecretory neurons of the SON showed a cytoplasmic membrane reinforced by the apposition of glial prolongations. The possible origin and function of these GCBs and lamellae are discussed here.

El sistema neurosecretor del ratón de envejecimiento acelerado: un modelo de deterioro cognitivo

Introduccion el raton de envejecimiento acelerado (senescence-accelerated mouse [SAM]) es un modelo de ciclo vital breve. Una vez alcanza la edad reproductiva, comienza un rapido envejecimiento que cursa con deterioro cognitivo. El sistema neurosecretor del hipotalamo esta formado por los nucleos supraoptico y paraventricular, cuyas neuronas sintetizan las hormonas oxitocina y vasopresina. Una caracteristica del hipotalamo del SAM es la presencia de un nucleo que no aparece en otras cepas de ratones, el nucleo accesorio. Se analiza el hecho de que los valores elevados de neurohormonas pueden participar en los procesos de envejecimiento y deterioro cognitivo. Material y metodos hemos utilizado ratones de ambos sexos de la cepa SAM en sus 2 variedades; de pronto envejecimiento (SAMP8), que tienen un ciclo vital de unos 12 meses, y de envejecimiento retardado (SAM-R1), que viven unos 17 meses. Ademas, para comparar los resultados utilizamos ratones de las cepas Swiss y AKR/J. Se perfundio a los animales y se utilizaron las tecnicas de tionina, inmunocitoquimicas (oxitocina y vasopresina) y DiI para analizar las proyecciones hipotalamicas. Los estudios cuantitativos del numero de neuronas se realizaron por medio de un analisis estereologico. Resultados la caracteristica principal del hipotalamo de los ratones SAM es la presencia del nucleo accesorio que no aparece en las otras cepas analizadas. Este nucleo posee unas 200 neuronas, que en su mayoria sintetizan vasopresina y solo unas pocas (13%), oxitocina. Conclusiones los resultados obtenidos en esta cepa de ratones de envejecimiento acelerado se relacionan con el hecho observado en humanos de que las neuronas neurosecretoras del hipotalamo se caracterizan por un incremento de su actividad en la etapa de envejecimiento y en ciertos trastornos neuropatologicos.

P1-235: Lack association between bullous pemphigoid and dementia

ods: The subjects were participants of the Uppsala Longitudinal Study of Adult Men (ULSAM), which started when they were 50 years old. In the present study, baseline data were collected from a follow-up at age 70 (n 888). Measurements included fasting plasma glucose, insulin, oral glucose tolerance test (OGTT) and peripheral insulin sensitivity estimated by the euglycemic clamp technique. EIR was based on 30 minutes data from the OGTT. Cognitive function was assessed three times during the follow-up and participants with signs of impairment underwent a detailed diagnostic workup. Additional cases of dementia were identified through medical records. By the end of 2005, median 11.6 years after baseline, 61 men had developed AD according to the NINCDS-ADRDA and DSM IV criteria. CT scans were consistent with the diagnosis. Associations were analyzed using Cox proportional hazard analyses. Results: We did not find any association between diabetes, insulin sensitivity and AD. In the non-diabetic subjects (n 798), however, a decreased early insulin response was associated with higher risk of AD (HR/1SD 1.30, CI 1.06-1.48, p 0.019). The same odds ratio was obtained after adjustment for the insulin sensitivity index (M/I ratio), APOE genotype, BMI, hypertension, total cholesterol and education level (HR/1SD 1.27, CI 0.99-1.47 p 0.054). Studies on the association between glucose metabolism and vascular dementia and MCI (mild cognitive impairment) are in progress. Conclusions: In this longitudinal study, insulin sensitivity measured by the euglycemic clamp technique was not associated with AD. An impaired early insulin response, a marker of -cell dysfunction, was associated with higher risk of AD even after adjustment for other risk factors.