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Artigos
Publicados em Periódicos
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P060-00 Extended chromatin
fibres: crystallinity, molecular order and reactivity to concanavalin-A
Vidal BC* The reproducible formation of extended chromatin
fibres, beads and superbeads was studied in chicken erythrocytes
and mouse liver cells treated with NaCl and Triton X-100 solutions
and positioned vertically, prior to staining with toluidine
blue at pH 4.0, con-A binding and examination with polarization
microscopy, or to observations at the electron microscopy
level. DNA molecular order and crystallinity as assessed by
optical ansiotropies as well as glycoprotein mannose/glucose
residues were found to be well preserved in condensed and
noncondensed chromatin after formation of the extended chromatin
fibres. These results were associated with chromatin mobility
data. Cell Biology International 24(10): 723-728, 2000. IF
= 0.731 *E-mail: vidal@unicamp.br
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| P061-00
Image analysis of DNA fragmentation and loss in V79 cells under
apoptosis Maria SS, Vidal BC*, Mello MLS* Image analysis of
Feulgen-stained V79 cells after three days in culture was used
to discriminate apoptotic cells and cells suspected to be undergoing
apoptosis from control cells, based on parameters such as Feulgen-DNA
content, degree of chromatin condensation and nuclear areas,
in association with visual morphology. Three nuclear phenotypes
were defined in terms of morphological characteristics and levels
of chromatin condensation. Image analysis procedures proved
to be a useful tool for discriminating cells in the early stages
of apoptosis. Genetics and Molecular Biology 23: 109-112, 2000.
IF = 0.250 *E-mail: vidal@unicamp.br,
mlsmello@unicamp.br |
| P062-00
Chromatin organization in normal and cancer cells Mello MLS*,
Vidal BC* A brief overview on basic concepts regarding chromatin
organization and supraorganization in normal, transformed and
tumorigenic cells was presented. Reference to some unsolved
questions on morphological images and chromatin physiology relationships
was emphasized. Journal of Women's Cancer 2(2): 73-78, 2000.
*E-mail: mlsmello@unicamp.br,
vidal@unicamp.br |
| P063-00
Nuclear phenotype changes after heat shock in Panstrongylus
megistus (Burmeister) Garcia SL, Mello MLS*, Rodrigues VLCC,
Garcia NL The nuclear phenotypes of Malpighian tubule epithelial
cells of male nymphs of the blood-sucking insect, P. megistus,
subjected to short- and long-duration heat shocks at 40oC were
analyzed immediately after the shock and 10 and 30 days later.
The frequency of the various nuclear phenotypes identified suggests
that the forms of cell survival (unravelled heterochromatin,
nuclear and cell fusion), present in this species, were not
sufficient or efficient enough to protect all of the Malpighian
tubule cells from the deleterious effects of the stress. Memórias
do Instituto Oswaldo Cruz 95(2): 271-277, 2000. IF = 0.636 *E-mail:
mlsmello@unicamp.br |
| P064-00
Changes in nuclear phenotypes following cold shocks in Panstrongylus
megistus (Burmeister) Garcia SL, Mello MLS*, Garcia NL, Rodrigues
VLCC The nuclear phenotypes of Malpighian tubule epithelial
cells of P. megistus were studied immediately after a short
(1 h) cold shock at 0oC, and 10 and 30 days later. The objective
was to compare the response to a cold shock with that reported
to occur after hyperthermia, in order to provide insight into
the cellular effect of cold in this blood-sucking insect species.
Most of the changes detected have also been found in heat-shocked
specimens, except for nuclear fusion which was found to be less
effective or necessary in cold-shocked specimens than that induced
by heat shock. Heat shock proteins were assumed as the best
candidates for effective protection of the cells and the insects
from the drastic damage caused by low temperature shocks. Memórias
do Instituto Oswaldo Cruz 95(6): 893-898, 2000. IF = 0.636 *E-mail:
mlsmello@unicamp.br |
| P065-00
DNA fragmentation in programmed cell death in nucleate erythrocytes:
a cytochemical analysis Mello MLS*, Maria SS, Schildknecht PHPA,
Grazziotin NA The frequency and responsiveness to the TUNEL
assay were used to compare the DNA fragmentation pattern associated
with programmed cell death in nucleate erythrocytes of the circulating
blood in different species in which the life span and/or metabolic
activities of the red blood cells vary considerably. The results
reported here, especially in Rana catesbeiana indicate that
further studies are required for a better understanding of cell
death in vertebrate nucleate erythrocytes. Acta Histochemica
et Cytochemica 33(5): 15-19, 2000. IF = 0.517 *E-mail: mlsmello@unicamp.br |
| P066-00
Antiulcerogenic effect of a hydroalcoholic extract and its
organic fractions of Neurolaena lobata (L.) Gracioso JS, Hiruma-Lima
CA, Brito ARMS* Neurolaena lobata is a species used widely in
Caribbean folk medicine to treat gastric pain and ulcers. Fractions
of a hydroalcoholic extract of N. lobata aerial parts were studied
for their ability to prevent ulceration of the gastric mucosa.
In the stress-induced gastric model these fractions produced
a significant reduction of gastric lesion formation. HE, HxF
and CIF fractions also reduced significantly the gastric lesions
induced by the combination of indomethacin and bethanechol,
and the ulcers induced by HCl/ethanol solution (P < 0.05). The
pylorus-ligature experiment demonstrated that the studied fractions
changed significantly the gastric juice parameters. In the animals
pre-treated orally with the HxF fraction, prostaglandin synthesis
was increased significantly and free mucus production was increased
by 54% in the gastric mucosa (P < 0.001). The data suggest that
the HE and mainly the HxF fractions from N. lobata present a
significant anti-ulcer effect when assessed in these ulcer-induced
models. It is assumed that the mechanism underlying this antiulcerogenic
effect is possibly related to an increased activity of the defensive
mechanisms of the stomach, such as prostaglandin synthesis and
mucus production. Phytomedicine 7(4): 283-289, 2000. IF = 0.185
*E-mail: abrito@unicamp.br
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| P067-00
The juice of fresh leaves of Boerhavia diffusa L. (Nyctaginaceae)
markedly reduces pain in mice Hiruma-Lima CA, Gracioso JS, Bighetti
EJB, Robineou LG, Brito ARMS* The decoction or juice of leaves
of Boerhavia diffusa L. (Nyctaginaceae) is used in Martinican
folk medicine for its analgesic and anti-inflammatory properties.
Here we studied the acute oral toxicity of a crude extract obtained
from a lyophilized decoction (DE) and from the juice (JE) of
fresh leaves. No signs of toxicity were found up to the dose
of 5000 mg/kg (p.o.) in mice. The extracts of B. diffusa were
also investigated for their anti-edematogenic effect on carrageenan-induced
edema in mice. However, neither extract inhibited the paw edema
induced in mice (P > 0.05). The results show that the active
antinociceptive principle of B. diffusa is present mainly in
the juice of fresh leaves and has a significant antinociceptive
effect when assessed in the pain models used. The mechanism
underlying the analgesic effect of fresh leaves of B. diffusa
is possibly related to interaction with the opioid system. Journal
of Ethnopharmacology 71(1-2): 267-274, 2000. IF = 0.687 *E-mail:
abrito@unicamp.br |
| P068-00
Gastroprotective effect of essential oil from Croton cajucara
Benth. (Euphorbiaceae) Hiruma-Lima CA, Gracioso JS, Rodriguez
JA, Haun M, Nunes DS, Brito ARMS* The gastroprotective activity
of the essential oil from the bark of Croton cajucara Benth
was assessed in three different models of experimentally induced
gastric ulcer in mice. At oral dose of 100 mg/kg the essential
oil reduced gastric lesions induced by hypothermic restraint
stress and HCl/ethanol significantly. In the HCl/ethanol model
a dose-dependent gastroprotective effect was found. Significant
changes in gastric parameters were found after intraduodenal
administration of essential oil under ligated pylorus conditions.
Acute toxicity of essential oil was assessed in mice. The LD50
values were 9.3 and 680 mg/kg for oral and intraperitoneal administrations,
respectively. A dose-dependent cell viability inhibition was
found in V79 fibroblast cell cultures with an IC50 of 22.9 mg/ml.
These results support the pharmacological use of the essential
oil from Croton cajucara. Journal of Ethnopharmacology 69(3):
229-234, 2000. IF = 0.687 *E-mail: abrito@unicamp.br |
| P069-00
Locomotor response to an openfield during C57BL/6J active and
inactive phases: differences dependent on conditions of illumination
Valentinuzzi VS, Buxton OM, Chang AM, Scarbrough K, Ferrari
EAM*, Takahashi JS, Turek F Time of day has proven to be a source
of variability in diverse behavioral measures. Knowledge of
the pattern of this temporal effect and its exogenous or endogenous
origin is essential for a precise description of any behavior.
Here we analyzed the effect of the external light-dark cycle
and the internal rest-activity rhythm on the response of C57BL/6J
mice to a novel environment: 1. animals maintained in a 12:12
light:dark cycle were tested in an openfield at six different
times of day; 2. the animals were kept in dim green light where
entrainment was maintained by a skeleton photoperiod (two15-minute
bright light pulses separated by 12 hours of green dim light).
No effect of circadian phase on ambulation or habituation of
the response to the openfield was observed. It is suggested
that spatial novelty is equally arousing regardless of circadian
phase and that the conditions of illumination can dramatically
alter the response to a novel environment. Physiology & Behavior
69: 269-275, 2000. IF = 1.285 *E-mail: elenice@unicamp.br
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