Effect of electrolytic lesion of the median raphe nucleus on behavioral and physiological measures of stress.

The effect of electrolytic lesion of the median raphe nucleus was measured on behavioral and physiological parameters related to stress 24 h after the lesion. In of the elevated plus-maze the lesion decreased the percentage of open arm entries and tended to shorten the time spent on the open arms indicating an increase in anxiety. In contrast, the lesion markedly increased the time spent in the bright (aversive) compartment of the light-dark box and decrease in attempts to cross from the dark toward the bright compartment, an anxiolyic effect. With the exception of plasma prolactin level, which was lowered by the lesion, the physiological measures used in the present study indicate that the lesioned animals are under stress. Thus, death rate and weight loss after the surgery were higher in lesioned than in control animals. In addition, lesioned animals showed higher plasma corticosterone levels, a high incidence of gastric ulcers in the fundus and a depressed immune response to the mitogen concavaline A. These results highlight the importance of the median raphe nucleus in the regulation of stress and anxiety. They also show that behavioral and physiological measures of stress may be dissociated.

Regression of the lateral oviducts during the larval-adult transformation of the reproductive system of Melipona quadrifasciata and Frieseomelitta varia

Toward the end of the larval phase (pre-pupa), the reproductive systems of Melipona quadrifasciata and Frieseomelitta varia workers are anatomically similar. Scanning electron microscopy showed that during this developmental phase the right and left ovaries are fused and form a heart-shaped structure located above the midgut. Each ovary is connected to the genital chamber by a long and slender lateral oviduct. During pupal development, the lateral oviducts of workers from both species become extremely reduced due to a drastic process of cell death, as shown by transmission electron microscopy. During the lateral oviduct shortening, their simple columnar epithelial cells show some signs of apoptosis in addition to necrosis. Cell death was characterized by cytoplasmic vesiculation, peculiar accumulation of glycogen, and dilation of cytoplasmic organelles such as mitochondria and rough endoplasmic reticulum. The nuclei, at first irregularly contoured, became swollen, with chromatin flocculation and various areas of condensed chromatin next to the nuclear envelope. At the end of the pupal phase, deep recesses marked the nuclei. At emergence, worker and queen reproductive systems showed marked differences, although reduction in the lateral oviducts was an event occurring in both castes. However, in queens the ovarioles increased in length and the spermatheca was larger than that of workers. At the external anatomical level, the reproductive system of workers and queens could be distinguished in the white- and pink-eyed pupal phase. The metamorphic function of the death of lateral oviduct cells, with consequent oviduct shortening, is discussed in terms of the anatomical reorganization of the reproductive system and of the ventrolateral positioning of adult worker bee ovaries. (C) 2000 Wiley-Liss, Inc.

Ultrastructural alterations of choroid plexuses of lateral ventricles of rats (rattus norvegicus) submitted to experimental chronic alcoholism

Adult male rats (Wistar lineage) were alcoholized with sugar cane liquor diluted at 30° GL during 300 days and sacrificed every 60 days in 5 stages. Samples of choroid plexuses of lateral ventricles were collected and examined at transmission electronic microscope to detect possible ultrastructural alterations and to raise possible pathological correlations. Gradual changes were observed in these animals during all the experiment: dilatation and enlargement of cisternae of Golgi complex, dilatation of RER, presence of digestive vacuoles and a large amount of pinocytic vesicles as well as vesicles with electronlucent content throughout cytoplasm, as well as an enlargement of intercellular space between basolateral interdigitation of the cells and of the connective tissue. The changes observed in the epithelium and connective tissue of choroid plexuses specially in 240 and 300 days of treatment are presumably due to a disturbance in hydroelectrolitic homeostasis, contributing to several morpho-functional disturbs of central nervous system. No changes were observed in the control group animals.

A comparison of nasopharyngeal endoscopy and lateral cephalometric radiography in the diagnosis of nasopharyngeal airway obstruction

Two auxiliary methods of diagnosing nasopharyngeal airway obstruction were compared. Cephalometric radiography and nasopharyngeal videoendoscopy were evaluated for efficacy in terms of reproducibility and validity. Thirty orthodontic patients (7 to 12 years of age) seeking otorhinolaryngologic treatment for mouth breathing, or mouth and nose breathing, had nasopharyngeal endoscopy and radiographic examinations performed on the same day. Two otorhinolaryngologists analyzed the results. Nasopharyngeal endoscopy was more reliable in identifying all the obstructive nasopharyngeal processes. Endoscopy obtained kappa index scores of almost perfect agreement for diagnosis of posterior nasal septum deviation, of substantial agreement for anterior nasal septum deviation and lower turbinate hypertrophy, and of moderate agreement for middle turbinate hypertrophy. Lateral cephalometric radiography obtained scores of perfect agreement for imaging hypertrophy of the middle turbinate, of almost perfect agreement for imaging hypertrophy of the posterior portion of the inferior turbinate, and of substantial agreement for imaging hypertrophy of the inferior turbinate. Radiographic diagnoses of hypertrophy of the middle and lower turbinates exhibited high sensitivity and low specificity when compared with diagnoses by nasopharyngeal endoscopy.

Histoenzymological and ultrastructural changes in lateral muscle fibers of Oreochromis niloticus (Teleostei: Cichlidae) after local injection of veratrine

The effects of veratrine have been investigated in mammalian, amphibian, and crustacean muscle, but not in fish. In this work, the action of veratrine was studied in the lateral muscle of the freshwater teleost Oreochromis niloticus after intramuscular injection. Histoenzymological typing and electron microscopy of muscle fibers before and 15, 30, and 60 min after veratrine injection (10 ng/kg fish) were used to indirectly assess the morphological changes and the oxidative and m-ATPase activities. In some cases, muscles were pretreated with tetrodotoxin to determine whether the ultrastructural changes were the result of Na+ channel activation by veratrine. Veratrine altered the metabolism of fibers mainly after 30 min. Oxidative fibers showed decreased NADH-TR activity, whereas that of glycolytic and oxidative-glycolytic type fibers increased. There was no change in the m-ATPase activity of the three fiber types, except at 60 min postveratrine, when a novel fiber type, which showed no reversal after acidic and alkaline preincubations, appeared. Ultrastructural damage involved sarcomeres, myofibrils, and mitochondria, but the T-tubules remained intact. Pretreatment with tetrodotoxin (1 ng/ml) prevented the ultrastructural changes caused by veratrine. These results show that in fish skeletal muscle veratrine produces some effects that are not seen in mammalian muscle.

Mineral trioxide aggregate repair of lateral root perforations

This study was conducted to observe the healing process of intentional lateral root perforation repaired with mineral trioxide aggregate (MTA). Forty-eight root canals of dogs' teeth were instrumented and filled. After partial removal of the filling, an intentional perforation was made with a bur in the lateral area of the root. The perforations were repaired with MTA or Sealapex (control group). Histological analysis occurred 30 and 180 days after treatment. Results showed no inflammation and deposition of cementum over MTA in the majority of the specimens. In the 180-day period, Sealapex exhibited chronic inflammation in all the specimens and slight deposition of cementum over the material in only three cases. In conclusion, MTA exhibited better results than the control group. Copyright © 2001 by The American Association of Endodontists.

Electromyographic validation of the trapezius and serratus anterior muscles in frontal-lateral cross, dumbbells exercises

Based on the lack of electromyographic researches on sport and programmes of physical conditioning, we can say that it is necessary to reexamine some exercises routinely used in the programmes of physical conditioning. Thus, the trapezius and serratus anterior muscles were studied electromyographically so that we could evaluate the validity in some ways of execution of the frontal-lateral cross, dumbbells exercises for the development of these muscles. We analyzed 24 male volunteers, 18 to 25 years old, using a 2-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes. For the execution of the exercise it was used a supine bench, a straight board and two bars of 40 cm made of light wood. The results showed that TS acted preferentially in standing modality and in the inclined supine modality, however with activity levels that do not justify its inclusion in physical fitness programmes.

Electromyographic validation of the trapezius and serratus anterior muscles in the rowing and frontal-lateral cross, dumbbells exercises

The trapezius and serratus anterior muscles were studied in four modalities of rowing exercises executed with two grips, middle and closed, in comparison with the four different modalities of frontal-lateral cross, dumbbells exercise. It was used 24 male volunteers, 18 to 25 years old using a 2-channel TECA TE 4 electromyograph and Hewlett Packard surface electrodes. The results showed that TS acted in a higher significant way in all the modalities of rowing than in the supine lateral raise, inclined supine lateral raise and reverse supine lateral raise, dumbbells exercises, and demonstrated no standing frontal-lateral cross, dumbbells. The SI acted more significantly difference among all the execution modalities of rowing and the inclined supine lateral raise, dumbbells exercises than in all the rowing exercises; even though the activity levels do not make us suggest them as an excellent group of exercises for the development of this muscle.

The thrombocyte aggregation process in the turtle Phrynopys hilarii (Chelonia). An ultrastructural study

This study investigates the thrombocyte aggregation process in the South American fresh water turtle (Phrynopys hilarii) using electron microscopy. Blood was taken from surgically exposed lateral neck vessels often turtles Phrynopys hilarii during the spring and summer seasons, when the mean temperature is 37°C. Blood samples were fixed with Karnovsky solution for processing by transmission electron microscopy. The turtle thrombocytes were spindle-shaped with lobulated nuclei. Prominent vesicles and canaliculi were found throughout the cytoplasm. The cytoplasm organelles showed an agranular endoplasmatic reticulum, Golgi complex near the centrioles and scattered free ribosomes. These cells are similar to bird thrombocytes but distinct from fish and frog thrombocytes. Blood clotting time was 5 min ± 30 sec measured by the Lee and White method. Structural alterations resulting from the aggregation process occurred after activation. Thrombocytes developed numerous filopodial projections, an increased number of vacuoles and changed from spindle to spherical shape. P. hilarii thrombocytes have different morphologic characteristics compared to other non-mammalian vertebrate cells. These cells can participate in the aggregation process, as observed in birds.

Cell nucleus activity during post-embryonic development of Apis melliferaL. (Hymenoptera: Apidae). Intranuclear acid phosphatase

We report nuclear acid phosphatase activity in the somatic (intra-ovariolar and stromatic) and germ cells of differentiating honey bee worker ovaries, as well as in the midgut cells of metamorphosing bees. There was heterogeneity in the intensity and distribution of electron dense deposits of lead phosphate, indicative of acid phosphatase activity in the nuclei of these tissues, during different phases of post-embryonic bee development. This heterogeneity was interpreted as a variation of the nuclear functional state, related to the cell functions in these tissues.

Electromyographic validation of basic exercises for physical conditioning programmes IV. Analysis of the deltoid muscle (anterior portion) and pectoralis major muscle (clavicular portion) in frontal-lateral cross, dumbbells exercises

The electromyographic activity of the shoulder muscles deltoid - anterior portion (DA) and pectoralis major - clavicular portion (PMC) was tested on 24 male volunteers using a 2 channel TEC A TE4 electromyograph and Hewlett Packard surface electrodes during the execution of four different modalities of frontal-lateral cross, dumbbells exercises. The results showed that all of the tested exercises developed high levels of action potential for both muscles. So, we jusfity the indication of all of them for physical fitness programmes for DA and PMC. Some suggestions to the use of the tested exercises are presented.

Electromyographic validation of basic exercises for physical conditioning programmes V. The comparison of the response in the deltoid muscle (anterior portion) and the pectoralis major muscle (clavicular portion) determined by the frontal-lateral cross, dumbbells and the rowing exercises

The action potential level for shoulder muscles deltoid-anterior portion (DA) and pectoralis major-clavicular portion (PMC) determined by four different modalities of execution of rowing exercises, each one with two different grips, was recorded. These were compared with the action potential level determined for the same muscles by four different modalities of execution of the frontal-lateral cross, dumbbells exercises. Twenty-four male volunteers were examined using a 2 channel TECA TE4 electromyograph and Hewlett Packard surface electrodes. The statistic analysis showed significant (p<0,05) superiority for all the frontal-lateral cross, dumbbells exercises in comparison to all rowing exercises for the PMC, for the DA this generalized supremacy was not observed.

Influence of angiotensin II receptor subtypes of the paraventricular nucleus on the physiological responses induced by angiotensin II injection into the medial septal area

Objective - We determined the effects of losartan and PD 123319 (antagonists of the AT1 and AT2 angiotensin receptors, respectively), and [Sar1, Ala8] ANG II (a relatively peptide antagonist of angiotensin receptors) injected into the paraventricular nucleus (PVN) on water and 3% NaCl intake, and the diuretic, natriuretic, and pressor effects induced by administration of angiotensin II (ANG II) into the medial septal area (MSA) of conscious rats. Methods - Holtzman rats were used. Animals were anesthetized with tribromoethanol (20 mg) per 100 grams of body weight, ip. A stainless steel guide cannula was implanted into the MSA and PVN. All drugs were injected in 0.5-μl volumes for 10-15 seconds. Seven days after brain surgery, water and 3% NaCl intake, urine and sodium excretion, and arterial blood pressure were measured. Results - Losartan (40 nmol) and [Sar1, Ala8] ANG II (40 nmol) completely eliminated whereas PD 123319 (40 nmol) partially blocked the increase in water and sodium intake and the increase in arterial blood pressure induced by ANG II (10 nmol) injected into the MSA. The PVN administration of PD 123319 and [Sar1, Ala8] ANG II blocked whereas losartan attenuated the diuresis and natriuresis induced by MSA administration of ANG II. Conclusion - MSA involvement with PVN on water and sodium homeostasis and arterial pressure modulation utilizing ANGII receptors is suggested.

Longitudinal distribution of Copepoda populations in the transition zone of Paranapanema River and Jurumirim Reservoir (São Paulo, Brazil) and interchange with two lateral lakes.

Longitudinal changes in composition, abundance, and distribution of copepods were studied at the transition zone of Paranapanema River-Jurumirim Reservoir (SP, Brazil). The interchange of biotic material between marginal lakes and the river system was also examined. Water samples were obtained from 6 stations along a stretch of 13 km of the Paranapanema River, from an upstream reach with high water velocity up to the river mouth into Jurumirim Reservoir. Two other sites in lateral lakes were also sampled. Nine copepod taxa were identified: 3 calanoids (Argyrodiaptomus furcatus Sars, Notodiaptomus iheringi Wright, and N. conifer Sars) and 6 cyclopoids (Eucyclops Claus, Microcyclops Claus, Mesocyclops longisetus Thiébaud, Thermocyclops decipiens Fischer, T. minutus Lowndes, and Paracyclops Claus). Harpacticoids were also collected. Calanoid and cyclopoid nauplii and copepodids, and harpacticoids were the most abundant organisms. In general, there was a longitudinal decrease in copepod abundance, whereas an increase was detected near the lakes. The abundance of most copepods was inversely correlated with current velocity and suspended solids. Higher abundance was observed in the river main course during the rainy season, during which there is a higher connectivity between the lakes and the main river. This promotes exportation of biologic material from marginal lakes to the river system, a biotic exchange reflecting the importance of marginal lakes to the river community structure.

Intraepithelial alterations in the Guinea pig lateral prostate at different ages after estradiol treatment

The prostate is an accessory gland of the mammal reproductive system with great volume and high functional importance. Many works infer that, in addition to the androgenic ones, the estrogen can be associated with benign prostatic hyperplasia and prostatic cancer, but no conclusive evidence exists on the role of estrogen in normal prostatic and neoplastic tissue. The objective of this work was to evaluate the effects of chronic administration of estradiol benzoate on the lateral prostate of guinea pigs in the pre-pubescent, pubescent, post-pubescent and adult phases, with emphasis on the modifications provoked by this hormone on the glandular epithelium. The analyses of the estradiol-treated and control groups were investigated using histological procedures and transmission electron microscopy. The histopathological analysis of the lateral prostate in the treated group revealed areas where epithelial dysplasia was observed, assuming at some places a pattern of epithelial stratification characteristic of prostatic intraepithelial neoplasia. After ultrastructural analysis, the following were observed: enlargement of the internal membranes, heterogeneity in the cellular types, hypertrophy of the basal cells and apparent decrease of cytoplasmic organelles in some cells of the prostatic intraepithelial neoplasia. Still, a loss of cellular polarity was observed, along with nuclei of various forms, sizes and heights - as well as irregular chromatin distribution patterns. Such alterations were found mainly in pubescent, post-pubescent and adult animals subject to the chronic administration of estradiol. These findings reinforce the already existent data in understanding the role of estrogen in the etiology of prostatic diseases.