Biomedical subjects

E E Calore

Publications and source records attributed to E E Calore.

At least 19 recordsLinked to original sources

PubMed2006

Morphometric studies of cardiac myocytes of rats chronically treated with an organophosphate.

Organophosphate intoxication induces an acute cholinergic syndrome, but the long-term effects of these compounds in the cardiocirculatory system are not known. The objective of the present work is to investigate if experimental chronic exposition to repetitive sublethal doses of organophosphate methamidophos can induce morphological changes in rat's hearts. Wistar albino adult male rats received a weekly enteral sublethal dose of the organophosphate methamidophos for 12 consecutive weeks. After that we have performed histological and morphometric studies of their hearts. We have observed hypertrophy of cardiac myocites in treated animals, which was confirmed by morphometric studies (measure of smaller diameter of cardiac myocites). One of the possible explanations for the cardiac hypertrophy would be persistent systemic arterial hypertension in treated animals. However, another possible explanation would be direct sympathetic stimulation.

Animals↗

PubMed2005

Morphometric studies of specific brain regions of rats chronically intoxicated with the organophosphate methamidophos.

Subtle neurological disturbances have been described in organophosphorus intoxication. Experimental studies have reported neuronal necrosis, particularly in animals experiencing seizures. The objective of the present work was to investigate if in rats (without seizures) exposed to an organophosphate agent, morphological changes occur in specific regions of the brain. The animals received 2.5 or 5.0 mg/kg methamidophos once a week for 2 months and were decapitated after 2 months 7 days of drug administration. We observed atrophy of the molecular layer of the parietal cortex without neuronal loss in specific cerebral regions. This would be due to atrophy or loss of neuronal ramifications but without neuronal loss.

Animals↗

PubMed2003

Salpingitis due to Entamoeba histolytica.

We describe the pathology of a unique case of Fallopian tube amebiasis, associated with hydrosalpinx, in a 21-year-old woman. She complained of lower abdominal pain, had a foul-smelling green vaginal discharge and fever during one week. There was a discrete increase in body temperature and a painful abdominal palpation at the lower right side, with signs of local peritoneal irritation. Pathological examination showed a marked dilatation of the fallopian tube and hydrosalpinx. Microscopic examination showed a poorly formed granuloma composed of large macrophages with many Entamoeba histolytica trophozoites inside the fallopian tube. Even though it is a rare disease the correct diagnosis of female genital tract amebiasis is of great importance for the indication of proper therapy.

Adult↗

PubMed2003

Effects of nicotine administration in developing muscle fibers of rats offspring.

The authors studied the effects of nicotine in developing skeletal muscles of rats. Pregnant Wistar rats received an enteral dose of nicotine (2.5, 5.0 or 10mg/kg, respectively, in groups G2, G5, and G10) from the 10th to the 18th or 20th days of pregnancy. Myotube atrophy was observed mainly in 20-day-old fetuses of G10. Twenty-day-old control fetus and of G2 and G5 had a high sarcoplasmic expression of desmin (weaker in G10). Vimentin expression was similar in 18-day-old fetuses of the control, G2, and G5 groups, but it was weaker in 20-day-old fetuses of the G2 and G5 groups. This would indicate an acceleration of the maturation pattern of vimentin expression in these intoxicated fetus. In conclusion, high doses of nicotine induce myotube atrophy and decrease of the expression of intermediate filaments, whereas relatively low doses of nicotine (G2 and G5) induce an early decrease of vimentin expression with no myofiber atrophy.

Animals↗

PubMed2002

Protective effect of early and late administration of pralidoxime against organophosphate muscle necrosis.

The objective of the present investigation was to study the protection afforded by a single administration of pralidoxime against the muscle necrosis induced by the organophosphate compound metamidophos at different times after intoxication. The fiber necrosis of the diaphragm muscle was quantified by a morphometric technique, comparing the area fraction occupied by necrotic muscle fibers in animals that received pralidoxime at different times after intoxication, i.e., 0, 1, 3, 6, and 12 h. Pralidoxime administration protected metamidophos-induced muscle necrosis in all groups studied except for the 12-h group. The earlier the administration of pralidoxime the greater the protection against muscle necrosis. This protection was not accompanied by complete reactivation of plasma cholinesterase activity. Results support the current opinion that pralidoxime should be administered as soon as possible after organophosphate intoxication, because in addition to reversing the muscarinic effects, early administration of pralidoxime also prevents muscle necrosis--which could impair muscular function and respiratory condition. The time difference between recovery of plasma cholinesterase activity and muscle necrosis protection indicates that this method is not completely trustworthy for patient follow-up, since some improvement may occur in spite of the low plasma cholinesterase activity.

Animals↗

PubMed2002

Distribution of COX-negative mitochondria in myofibers of rats intoxicated with Senna occidentalis seeds.

We have described that administration of seeds or parts of the seed of Senna occidentalis (coffee senna) for long periods, induces histochemical changes in the skeletal muscles of hens and rats that are characteristic of a mitochondrial myopathy--as decrease of SDH and COX activity, with some COX negative fibers. In this experimental model of mitochondrial myopathy, as in many human mitochondrial diseases, there is a random distribution of COX negative fibers. Some fibers are completely COX negative while others are partially negative and others are completely positive. In the present work we have studied the distribution of COX negative mitochondria at transmission electron microscopy in skeletal muscle of rats in this experimental myopathy. In myofibers of intoxicated animals the expression of COX was heterogeneous. The histochemical reaction was observed in the internal membrane (more evident in mitochondrial cristae) of all mitochondria of some myofibers, while it was almost absent in other myofibers. In these myofibers the great part of the mitochondria were negative for COX reaction while other ones had a weak expression of this enzyme (dot or focal expression of COX). Our results indicated that the COX mitochondrial activity is heterogeneously impaired in myofibers of rats intoxicated with S. occidentalis. These abnormalities remember those observed in some types of human mitochondrial myopathies.

Cytochrome-c Oxidase Deficiency↗

PubMed2002

Morphometric evaluation of muscle fiber types in different skeletal muscles of rats.

The purpose of the present work was to study some morphological differences of similar muscle fiber types--classified by ATPase reactions in different muscles of rats. Morphological parameters were used as stereological techniques at light and electron microscopic level. There was a great variation in the diameter of each muscle fiber type of different muscles. The smallest diameter of type 1 myofibers of the soleus was greater than the diameter of type 1 myofibers of other muscles. The diameter of type 1 myofibers of the soleus and of the lateral part of the gastrocnemius was almost twice the diameter of type 1 myofibers of sternocleidomastoid. The lateral and medial parts of gastrocnemius had the largest 2A and 2B muscle fibers. As a whole, among the studied muscles, myofibers of postural muscles of the posterior parts of the posterior limbs had the greatest diameter. Stereological analysis at electron microscopic level revealed that there were differences in the volume density of mitochondria in the different muscles. The quantity of mitochondria was greater in the diaphragm than in the gastrocnemius, soleus and sternocleidomastoid muscles. Our results suggested that the diameter of muscle fibers is more related to the resistance the muscle is submitted than to the continuous necessity of contraction. However, the quantity of mitochondria of oxidative fibers of the diaphragm would be related to continuous necessity of contraction and high oxidative necessity of this muscle.

Adenosine Triphosphatases↗

PubMed2001

Ki-67 expression in anal intraepithelial neoplasia in AIDS.

CONTEXT: AIDS is one of the most important risk factors for progression and recurrence of anogenital condyloma. In a previous work, we observed that patients with warts and high-grade AIN (HAIN) had recurrences more frequently than did patients with warts without AIN. The mechanisms of this increased incidence of high-grade lesions in AIDS are not known. OBJECTIVE: We studied the expression of the proliferative marker Ki-67 by immunohistochemical methods, in specimens of anal condyloma from HIV+ patients to clarify whether its expression can be associated to the grade of AIN. DESIGN: A retrospective study of histological specimens. SETTING: University referral unit. SAMPLE: 34 patients were divided into two groups: (1) condylomas with low grade AIN (LAIN), with 25 patients; and (2) condylomas with HAIN, with 9 patients. In this latter group we examined two areas: 2A (HAIN area) and 2B (LAIN area). MAIN MEASUREMENTS: The immunohistochemical reaction for Ki-67 was done on histological sections. Slices were lightly stained with hematoxylin, to help us in Ki-67 positive cell counting. The percentage of Ki-67 marked nuclei was calculated. We applied one-way variance analysis for statistics. RESULTS: The mean number of Ki-67 positive cells in group 1 was 19.68 +/- 10.99; in group 2 (area A) it was 46.73 +/- 10.409; and in area B it was 36.43 +/- 14.731. There were statistical differences between groups 1 and 2A and between groups 1 and 2B. Ki-67 positive cells predominated in the lower layer in LAIN. Positive Ki-67 cells were found in all layers in group 2A, and in group 2B they predominated in the two lower or in all layers of the epithelium. CONCLUSIONS: Our results suggest that LAIN areas (using routine staining techniques) in HAIN can have a biological behavior more similar to HAIN.

Adult↗

PubMed2001

Progression of cervical lesions in HIV-seropositive women: a cytological study.

It has been reported that cervical intraepithelial lesions have a more aggressive course in HIV-seropositive than in HIV-seronegative women. In the present investigation, the progression of these cervical lesions was studied in a group of HIV-seropositive women. Of 1,587 patients, 200 (12.6%) had a cytological diagnosis of squamous intraepithelial lesion (SIL) or invasive carcinoma. In 409 patients, more than one cytological smear was collected in 3(1/2) years. Progression occurred in 39 cases. In 24 (61.5%), the first diagnosis was benign cellular changes (BCC) and the second was low-grade SIL (LSIL) (1-yr interval in 21 cases); in 11 (28.2%), the first was BCC, and the second, high-grade SIL (HSIL) (1-yr interval in 9 cases); in 2 (5.0%), the first diagnosis was LSIL. and the second, HSIL (1-yr interval); in 2 (5.0%), the first was HSIL, and the second, invasive carcinoma (2-yr interval). These results point to the importance of cervical cytologic surveillance in HIV-seropositive patients.

AIDS-Related Opportunistic Infections↗

PubMed2001

Expression of Ki-67 can assist in predicting recurrences of low-grade anal intraepithelial neoplasia in AIDS.

PURPOSE: The incidence of anogenital squamous-cell carcinoma was observed to have increased since the beginning of the human immunodeficiency virus infection epidemic among male homosexuals, both with acquired immunodeficiency syndrome and without acquired immunodeficiency syndrome. It seems that immunosuppression is the most important risk factor for the progression of anogenital lesions, recurrences of anal condyloma, and development of anal carcinoma, in particular in acquired immunodeficiency syndrome. High-grade anal intraepithelial neoplasia was predominantly observed in the human immunodeficiency virus-positive men. We have also observed a high rate of recurrences of anal lesions in cases of high-grade anal intraepithelial neoplasia. However, there are many cases of recurrences of low-grade anal intraepithelial neoplasia that cannot be predicted by routine histologic studies. By using immunohistochemical methods, we studied the expression of Ki-67 in epithelial cells of low-grade anal intraepithelial neoplasia of patients with acquired immunodeficiency syndrome to try to predict recurrence of these lesions. METHODS: Anal biopsies of 38 patients were studied retrospectively. Of these patients, 14 had no recurrences (Group 1), and 24 patients had recurrence of the anal lesions before one year of follow-up (Group 2). RESULTS: The median percentage of Ki-67-positive cells in Group 1 was 6.3 +/- 7.03 and in Group 2 was 24.1 +/- 16.72. The difference between Groups 1 and 2 was statistically significant (P < 0.001). CONCLUSIONS: Our results showed a high correlation between the percentage of Ki-67-positive cells and recurrences. We concluded that Ki-67 counting in low-grade anal intraepithelial neoplasia can aid in predicting recurrences and therefore aid in the follow-up of these patients.

Acquired Immunodeficiency Syndrome↗

PubMed2001

Morphometric evaluation of nucleolar organizer regions in cervical intraepithelial neoplasia.

The objective of this study was to determine whether some morphometric parameters and two different methods of counting AgNOR dots were correlated with the grade of cervical intraepithelial neoplasia. Thirty uterine cervix biopsies (8 cases of cervicitis, 9 CIN I, CIN II and 6 CIN III) were studied. Two methods were used to count AgNOR dots. The first one consisted of counting the number of epithelial cells with 1, 2, 3, 4, or more dots. The second method, based on a computer analysis system, consisted of counting the total number of dots in 100 cells, without considering the number of dots per cell. Using the same computer analysis system, the following parameters were measured: area, diameter, perimeter, roundness and length of each dot. The following parameters were found to be correlated with the grade of intraepithelial neoplasia: 1) number of cells with 1 dot, which decreased with increasing grade of cervical intraepithelial neoplasia; 2) number of cells with 4 dots or more, which increased with increasing grade of cervical intraepithelial neoplasia; 3) total number of dots per 100 cells, which progressively increased with increasing grade of intraepithelial neoplasia. We conclude that counting cells with 4 or more dots is the more trustworthy parameter for distinguishing the grade of cervical intraepithelial neoplasia.

Biopsy↗

PubMed2001

Expression of Ki-67 in cervical epithelial cells in preneoplastic lesions of patients with AIDS.

The objective of the present investigation was to study the expression of the proliferation marker Ki-67 in cervical intraepithelial lesions in women with AIDS. We studied 18 low-grade cervical intraepithelial lesions (Lo-CIN) and 8 high-grade cervical intraepithelial lesions (Hi-CIN ) in AIDS patients and 18 Lo-CIN and 14 Hi-CIN in patients from the general population. Positive Ki-67 nuclei were counted. A significantly higher number of Ki-67-positive cells (p < 0.001) was found in Lo-CIN of AIDS patients (mean 29.18 +/- 10.44) as compared with Lo-CIN of general-population women (mean 17.08 +/- 7.40), whereas no significant difference in positive Ki-67 nuclei was observed in the Hi-CIN of AIDS patients and of patients from the general population (p > 0.05). We conclude that the proliferative potential of cervical cells in Lo-CIN - as studied by the expression of the proliferation marker Ki-67 - is higher in AIDS patients than in the general population.

Acquired Immunodeficiency Syndrome↗

PubMed2000

Histologic peripheral nerve changes in rats induced by deltamethrin.

Synthetic pyrethroid insecticides have been used in the last two decades largely because of their high activity as an insecticide and low mammalian toxicity. Some studies have demonstrated that these products, especially compounds with an alpha-cyano group, are toxic to the mammalian central nervous system (CNS) in acute intoxications. However, morphological studies are scarce. In the present work the histopathologic changes of the sciatic and tibial nerves of rats submitted to acute intoxication with the cyanopyrethroid deltamethrin were studied. For 3 consecutive days male Wistar rats received by oral gavage deltamethrin at a dose of 45 mg/kg body wt. On the 4th day fragments of sciatic and tibial nerves were studied by transmission electron microscopy (TEM) and teasing of individual nerve fibers. In addition, another group of rats were allowed to recover until the 10th day. Teasing of nerves of animals sacrificed on the 4th day revealed myelin ovoids, which are indicative of axonal damage. TEM demonstrated rare degenerated axons completely filled with organelles, in particular mitochondria, and with electron-dense lamellar bodies that resemble myelin figures. In addition, great cytoplasmic vacuolization caused by proliferation and dilation of the rough and smooth endoplasmic reticulum and Golgi apparatus was observed in some Schwann cells. No lesion was found 7 days after discontinuation of the treatment (group2). Since these histologic changes are transitory and scarce, the question arises: Are they related to the changes in NA(+), K(+)-ATPase activity or Na(+) channels caused by pyrethroid compounds?

Animals↗

PubMed2000

Detection of the 20-kDa virulence-associated antigen of Rhodococcus equi in malakoplakia-like lesion in pleural tissue obtained from an AIDS patient.

A malakoplakia-like lesion was detected in a pleural biopsy from an AIDS patient presenting clinical and radiologic features of pneumonia. Cultures of bronchoalveolar lavage and pleural fluid evidenced Rhodococcus equi as the causative agent of pleuro-pulmonary infection. Immunochemical characterization of the R. equi isolate showed the presence of a strain similar to the ATCC 33704 reference strain presenting the capsular antigen of serotype 4, and the intermediate virulence-associated antigen of 20-kDa. Histopathology of the patient's pleural biopsy showed plaques of macrophages interspersed with lymphocytes, and intracytoplasmic cocci and bacilli in macrophages, which were variably acid-fast positive. Immunohistochemistry of cocci, bacilli and their degradation products resulted strongly positive when stained with a mouse monoclonal antibody (MAb) produced against the 20-kDa antigen. This finding could have important implications for the pathogenicity of R. equi for human beings, since we do not know yet all the factors involved in the formation of malakoplakia. Indeed, the results obtained in the present study, taken together with the results obtained for pigs inoculated with R. equi strains of intermediate virulence (Madarame et al. 1998), raise the possibility that most strains presenting the 20-kDa antigen may be capable of inducing malakoplakia. If this hypothesis is confirmed by immunohistochemical analysis of human pulmonary malakoplakia cases due to R. equi, the detection of this antigen may be extremely helpful in the diagnosis and treatment of such patients. This is the first report of R. equi infection in human beings that suggests a relationship between pleural malakoplakia and the virulence-associated antigen of 20-kDa.

AIDS-Related Opportunistic Infections↗

PubMed2000

Mitochondrial metabolism impairment in muscle fibres of rats chronically intoxicated with Senna occidentalis seeds.

The chronic administration of S. occidentalis seeds was found to induce a mitochondrial myopathy in hens. This study was undertaken to determine if the chronic treatment with S. occidentalis seeds of rats (as a mammalian model) would induce a mitochondrial myopathy similar to those described in humans and to determine if the histological changes could be correlated with the amount of ingested seeds. Twenty-one days old rats were fed S. occidentalis seeds at different diet concentrations (1, 2, 3%). Rats fed 1% S. occidentalis seeds had only a few COX-negative muscle fibers in the pectoralis major muscle. Rats fed 3% Senna occidentalis seeds had a greater number of COX-negative fibers. Rats fed 2% had an intermediate number of COX-negative fibers. Activity of SDH and NADH-tr were decreased in rats of groups 2% and 3%. Our data indicate that a progressive mitochondrial metabolism impairment can be produced in rats fed S. occidentalis seeds and that this impairment can be correlated with the amount of ingested seeds.

Administration, Oral↗

PubMed2000

Toxicity testing of Senna occidentalis seed in rabbits.

The effect was investigated of administering ground Senna occidentalis seeds to rabbits in different concentrations (1%, 2%, 3% and 4%) in the ration. The experiment lasted 30 days and the toxic effects of the plant were evaluated on the basis of weight gain, histopathological, biochemical and morphometric parameters, as well as histochemistry and electron microscopy. Animals that received the ration containing 4% ground S. occidentalis seeds gained less weight (p < 0.05) and died in the third week. Histopathology revealed that the heart and liver were the main organs affected, with myocardial necrosis and centrolobular degeneration. There was a reduction in cytochrome oxidase activity in the glycogenolytic fibres, together with muscle atrophy, confirmed by the morphometric studies. Electron microscopy of the liver cells revealed dilated mitochondria, with destruction of the internal cristae.

Animal Feed↗

PubMed2000

Skeletal muscle pathology in 2 siblings infected with Toxoplasma gondii.

Skeletal muscle can be the site of inflammatory diseases that lead to muscle weakness, pain, and increased myogenic serum enzymes. Most of these inflammatory myopathies are idiopathic. In some cases inflammatory myopathies are due to infectious agents. We describe the pathological aspects of muscle biopsies of 2 Brazilian siblings who acquired toxoplasmosis at the same time and in similar conditions. One developed a tetraplegia that was confirmed to be due to inflammatory myositis due to toxoplasma. The other developed myocarditis, with heart failure, without skeletal muscle weakness. In both cases many toxoplasma organisms were observed in the muscle biopsies, but in case 1 only was there an inflammatory myopathy with myofiber necrosis; the inflammatory cells were predominantly macrophages with some CD4+ cells and rare CD20+ cells. In case 1, expression of CD54 was observed in many inflammatory cells as well in endothelial cells, but only in endothelial cells in case 2. After treatment with clindamycin and corticosteroids both cases had only partial improvement, case 1 with a residual muscle weakness and case 2 with residual cardiac insufficiency (requiring digoxin). These cases show that the presence of the parasite in myofibers is not enough to induce an inflammatory myositis with muscle cell necrosis. This suggests that immunological disturbances may contribute to the development of inflammatory myositis due to toxoplasma.

Adolescent↗

PubMed1999

Early expression of ubiquitin in myofibers of rats in organophosphate intoxication.

The degenerative process of the myofibers of the diaphragm of rats intoxicated with the organophosphate isofenphos, a compound that inhibits esterases, was studied at different intervals of intoxication. Early disorganization of the intermyofibrillar network and of the myofilaments, as well as dilatation of organelles, were observed by use of transmission electron microscopy. These changes precede macrophage invasion of the muscle fibers. Early expression of ubiquitin was observed in segments of muscle fibers by immunohistochemistry. Bands of polyubiquitin complexes in muscle homogenates were observed by immunoblotting. These bands disappeared in later stages of intoxication. A 42.5-kDa band corresponds to actin, as observed by immunoblotting using antisarcometric actin. This indicates relatively large amounts of polyubiquitin complex associated with sarcomeric actin in muscle fibers in early stages of intoxication. Based on these results it seems that actin is an important target in organophosphate-induced myofiber degradation and that the degradation of this protein-by the polyubiquitin pathway-may play an important role in the early disorganization of the sarcomere, as observed by electron microscopy. A possible role of the ubiquitin proteolytic pathway is that of trying to eliminate proteins modified in the early phases of muscle fiber degeneration, which is a necessary step for regeneration of the posterior segmental muscle.

Actins↗