Biomedical subjects

M J Cavaliere

Publications and source records attributed to M J Cavaliere.

At least 37 records · Page 2Linked to original sources

PubMed1998

Nerve biopsy in patients with AIDS.

Patients with AIDS can present clinical involvement of the peripheral nervous system due to different causes. In the present work, it was studied the histopathological changes in sural nerve biopsy of fifteen patients with AIDS with this clinical involvement. It was observed the presence of a polyarteritis nodosa-like vasculitis of small arteries with fibrinoid necrosis in the sural nerve of 3 patients, one of them associated to polyradiculitis due to cytomegalovirus infection (CMV). Six patients presented mild axonal loss by light microscopy. Three other patients had a more important axonal neuropathy with myelin ovoids by teasing. By the electron microscopy in these patients were observed some fibers with axonal damage. The other three patients had normal sural nerves. We concluded that sural nerve biopsy may be important in peripheral neuropathies or myelo-radiculo-polyneuropathies in AIDS especially to search for nerve vasculitis, because it can change the therapeutic approach.

Acquired Immunodeficiency Syndrome↗

PubMed1997

Experimental mitochondrial myopathy induced by chronic intoxication by Senna occidentalis seeds.

Histochemical and electron microscopic studies of biceps femoris, pectoralis major and rectus femoris of chronically treated birds with seeds of the poisonous plant Senna occidentalis (0.2% external/internal tegment), were performed. The muscles had similar features of human mitochondrial myopathy as ragged-red fibers, cytochrome-oxidase negative fibers, and weak activity of the oxidative enzymes. Fibers with lipid storage were also present. Acid phosphatase activity in rare muscle fibers was also detected, and represents probably a secondary degenerative process. By electron microscopy, enlarged mitochondria with disrupted or excessively branched cristae were seen. The present study presents a new experimental model of mitochondrial myopathy that may be useful for the best knowledge of this group of diseases and for experimental trials of drugs that could reverse the mitochondrial impairment in the mitochondrial myopathies.

Animals↗

PubMed1997

Silver staining method for nucleolar organizer regions in cervical smears.

The distribution of nucleolar organizer regions (NORs) was studied in Papanicolaou preparations of cervical smears in order to distinguish benign from preneoplastic lesions. Destained smears (six defined as normal, six as inflammatory with squamous metaplasia, six as CIN I, six as CIN II, and five as CIN III) were submitted to the Ag-NOR method after staining with Orange G and EA36. Ag-NOR count was performed in previously outlined fields on the smears. Statistically significant differences (P < .05) were found between the normal smears, inflammatory smears with squamous metaplasia, and each grade of CIN. We conclude that the Ag-NOR technique could be useful to evaluate cervical smears of doubtful interpretation, using previous demarcation of the abnormal fields/cells.

Female↗

PubMed1997

Mitochondrial myopathy in Senna occidentalis-seed-fed chicken.

Plants of the genus Senna (formerly Cassia) have been recognized as the cause of a natural and experimental syndrome of muscle degeneration frequently leading to death in animals. Histologically, it demonstrated skeletal and cardiac muscle necrosis, with floccular degeneration and proliferation of sarcolemmal nuclei. Recently, it was described as an experimental model of mitochondrial myopathy in hens chronically treated with Senna occidentalis. Currently, skeletal muscles of chicks intoxicated with seeds of the poisonous plant S. occidentalis were studied by histochemistry and electron microscopy. Since birth, the birds were fed ground dried seeds of this plant with a regular chicken ration at a dose of 4% for 11 days. Microscopic examination revealed, besides muscle-fiber atrophy, lipid storage in most fibers and a moderate amount of cytochrome oxidase-negative fibers. By electron microscopy, enlarged mitochondria with disrupted or excessively branched cristae were seen. This picture was characteristic of mitochondrial myopathy. These findings have hitherto remained unnoticed in skeletal muscle of young birds treated with S. occidentalis.

Animal Feed↗

PubMed1997

Study of organizer nucleolar regions by the argyrophil technique in cervical intraepithelial neoplasias.

Thirty three biopsies of the uterine cervix were studied by the AgNOR method, that identifies the nucleolar organizer regions. These comprised 9 cases of cervicitis (with or without squamous metaplasia), 9 cases of cervical intraepithelial neoplasia grade I (CIN I), 8 CIN II and 10 CIN III. A hundred cells were counted and classified according to the number of AgNOR dots. We use a more practical and fast method of AgNOR dots counting in cervical intraepithelial neoplasia, in that we exclude the two basal layers and count only cells with 4 or more dots. Statistically significant differences for AgNOR dots were found between cervicitis or CIN I and CIN II cases (p < 0.02) and between CIN II and CIN III cases (p < 0.001). No statistical difference was found between the cases of cervicitis and CIN I. It was concluded that this method of AgNOR counting can be useful in the identification and classification of individual cases intraepithelial neoplasia and their differentiation from eventual difficult cases of cervicitis.

Biopsy↗

PubMed1997

Cerebral amebiasis in the acquired immunodeficiency syndrome.

Rare cases of cerebral amebiasis have been described in AIDS patients. We report the case of a 46 year-old homosexual man with AIDS who developed an intermittent amnesia and a right palpebral ptosis. The cerebrospinal fluid contained 169 cells (75% lymphocytes). The patient died five days after hospitalization. Necropsy revealed thrombosis of small vessels of the periventricular regions as well as necrosis and hemorrhage of the periventricular tissue, cerebellum and brainstem. The inflammatory process was scarce and composed mainly of CD-68 positive macrophages. In these regions as well as in meninges there were many trophozoites of ameba of the Acanthamoeba group. Although cerebral amebiasis is rare even in AIDS, the clinician should be attentive to this diagnosis in patients with an insidious encephalitis and cerebral cognitive abnormalities, with or without focal motor signs.

AIDS-Related Opportunistic Infections↗

PubMed1996

[Organophosphate-induced myotoxicity].

Organophosphates comprise a group of chemical compounds extensively used in farming as insecticides, which cause accidental poisoning in animals and men and are also used in suicide attempts. The toxicity of these compounds is due especially to the cardiac and respiratory impairment in consequence of autonomic nervous system disorders. However, it is known that some of these products induce a myopathy in experimental animals and humans. This myopathy is characterized by muscle cell degeneration, involving above all the respiratory muscles. Based on the fact that this involvement certainly enhances the respiratory impairment, this study offers an experimental method for routine evaluation of organophosphate myotoxicity, using a minimal and sufficient battery of stains and histochemical reactions, for muscle necrosis quantification. For this purpose, albino rats (Wistar) treated with the organophosphate paraoxon, were used both with and without antidotes (atropine or pralidoxime). Muscle fiber necrosis in the diaphragm of the rats treated with paraoxon or paraoxon and atropine, that affected about 15% of the fibers in some areas, was detected. In the group treated with paraoxon and pralidoxime, a minimal necrosis was seen, revealing a protective role of this later antidote during the development of myopathy.

Animals↗

PubMed1995

Skeletal muscle pathology in systemic sclerosis.

OBJECTIVE: Systemic sclerosis (SSc) is characterized by abnormal deposition of collagen in the skin and by visceral involvement. Muscle weakness is a relatively frequent complication of SSc, although severity varies. We studied muscle pathology in patients with SSc with progressive muscle involvement. METHODS: We performed histochemical and immunohistochemical investigations to detect neural cell adhesion molecule (NCAM). RESULTS: Five of the 6 cases of SSc expressed NCAM in atrophic angulated fibers (some fibers stained heavily with oxidative enzymes). CONCLUSION: Neurogenic involvement in SSc is more frequent than reported.

Adolescent↗

PubMed1995

Empyema with malakoplakic-like lesions by Rhodococcus equi as a presentation of HIV infection.

Rhodococcus equi (Corynebacterium equi) is an aerobic actinomycetes, well described as a cause of pulmonary infection in different animals as horses, pigs and cows. This pathogen has a coccobacillar aspect and a variable acid-fast stain in tissues. Rare cases of human infection by Rhodococcus species were described, the majority by Rhodococcus equi, especially in patients with immunodeficiency syndrome (AIDS) in advanced stages of the disease. Usually the diagnosis of infections by Rhodococcus species is performed by positive blood or bronchoalveolar lavage cultures. Here we described a case of a pleuro-pulmonary infection by Rhodococcus equi, with malakoplakic-like lesions, that was the first manifestation of AIDS, whose diagnosis was performed by pleural biopsy (acid-fast bacteria with a variable coccobacillar aspect inside macrophages) and pleural fluid culture.

AIDS-Related Opportunistic Infections↗

PubMed1994

Frequency of Candida sp infection in tuberculous patients with acquired immunodeficiency syndrome: morphological and immunocytochemical study in sputum.

Sputum samples from AIDS patients with and without pulmonary tuberculosis were analyzed morphologically and immunocytochemically to determine the frequency of occurrence of Candida sp. Mycobacterial infection was detected by bacterioscopy and/or culture and cytological evaluation was performed using Papanicolaou and Toluidine Blue staining. Immunoreaction for Candida sp was performed using polyclonal antibody in selected cases with fungal structures in smears stained by the Papanicolaou or Toluidine Blue method. An increased frequency of Candida sp (2.5 times) was observed in the tuberculous group compared to the group of AIDS patients without tuberculosis. The Toluidine Blue stain showed good results for the detection of Candida sp in sputum. Due to the increased risk of this opportunistic infection among more severely immunocompromised patients. Toluidine Blue staining of sputum samples submitted to analysis seems to be a reliable screening method.

AIDS-Related Opportunistic Infections↗

PubMed1994

An unusual case of muscular limb-girdle dystrophy and mitochondrial myopathy.

Limb-girdle muscular weakness and wasting could be caused by different diseases (inflammatory and hereditary myopathies, muscular dystrophies and neurogenic atrophies). Among these, Limb-Girdle Muscular Dystrophy (LGMD) is an heterogeneous group of pathologies that have progressive proximal limbs and girdle weakness, with some dystrophic features by the muscle biopsy. We studied a case of LGMD in an adult man with a typical histological and histochemical profile, associated to a mitochondrial deficit characterized by presence of ragged-red fibers, a histochemical Cytochrome Oxidase deficiency and abnormal mitochondria by ultrastructure.

Adult↗

PubMed1994

Hypertrophic motor and sensory neuropathy type I (Charcot-Marie-Tooth disease): ultrastructural study of sural nerve biopsy in members of a family.

Three members of a family with a hereditary neuropathy were studied. Light, electron microscopy and teasing of isolated fibres were performed. The findings confirmed the clinical and electrophysiological hypothesis of hypertrophic form of Charcot-Marie-Tooth disease. Hypertrophy of Schwann cells with the formation of onion bulb figures as the most evident ultrastructural feature, besides demyelination, remyelination and mild axonal degeneration. Recent data about the genetic transmission and pathogenesis of the hereditary motor and sensory neuropathies (HMSN) are discussed.

Adult↗

PubMed1994

Hyperthermic reaction to haloperidol with rigidity, associated to central core disease.

A 21-year-old female patient with psychotic symptoms developed hyperthermia, muscular rigidity and hypertension after administration of haloperidol. A muscle biopsy showed some atrophic and necrotic fibers, and a great number of fibers with central cores in the oxidative enzyme preparations. A related syndrome, Malignant Hyperthermia (MH), is sometimes associated with central core disease. The present case shows an association of a hyperthermic syndrome related to haloperidol with central core disease.

Adult↗

PubMed1993

Cervico-vaginal Chlamydia trachomatis infection in pregnant adolescent and adult women. A morphologic and immunofluorescent study.

We studied the incidence of cervical Chlamydia trachomatis (CT) in 65 adolescents aged between 14 and 19 years and 65 adults aged 20 years or more. All subject were more than three months advanced in a normal pregnancy. Two samples for cytology were obtained from each patient, one ecto- and endocervical, with Ayre's spatula and cytobrush, and one only endocervical with cytobrush. The first one was examined after Papanicolaou staining and the second one was examined with the easily performed immunofluorescence reaction to CT (IF)--Microtrak, SYVA. Twenty seven adolescent patients (41.5%) and fourteen adults (21.5%) had a positive IF test for CT; the rate in adolescents was significantly higher (P < 0.01) than in adults. The Papanicolaou (Pap) stained slides, examined blind for evidence of CT infection showed a sensitivity of 70.7%, a specificity of 95.5% and positive and negative predictive values of 87.8% and 87.6% respectively. Seven adolescents showed cytological signs of Papillomavirus (HPV) infection, and six of them were also CT positive; five had signs of HPV infection and 4 of them were CT positive.

Adolescent↗

PubMed1990

Chlamydia trachomatis in cervical uterine irradiated cancer patients.

Twenty-two women with uterine carcinoma with morphological alterations postradiation treatment suggestive of Chlamydia trachomatis infection were analyzed by direct immunofluorescence. The diagnosis was confirmed in 12 (54.4%) cases. Discussions of the presence of Chlamydia in irradiated cells were not found in the literature. This finding may signify a posttherapeutic morbidity or a preradiation infection.

Adenocarcinoma↗

PubMed1990

Changes in myelinated nerve fibers and skeletal muscle of rats exposed to high doses of permethrin.

Neurological signs and segmental demyelination in a cervical nerve were observed in rats treated orally with permethrin (300 mg/kg/day) for 5 days. Inflammatory and degenerative signals were recorded in the diaphragm muscle. These effects were more intense with the trade grade than with the technical grade product. The possible influence of the percentage of cis:trans isomers on the intensity of the observed effects is discussed.

Animals↗

PubMed1984

[Muscular biopsy in myasthenia gravis: histochemical and morphometric study of 4 cases].

Myasthenia gravis is a neuromuscular disease characterized by excessive fatigability of muscle function and particularly involves muscles innervated by the cranial nerves. It is believed that the defect is in the neuromuscular junction. The authors studied histochemical and morphometric findings in 4 patients with myasthenia gravis showing that the type II fibres were significantly smaller than the type I fibres.

Adenosine Triphosphatases↗

PubMed1983

[Polyneuropathy caused by parathion: clinical, electrophysiologic and histologic studies of a case].

A case of 38 year old man who worked with organochlorinated and Parathion during 5 years is reported. His follow-up was up to 2 years. The onset of the disease was characterized by cholinergic signs, headache, loss of weight, trembling, miokimias, fasciculations, ataxia, myotonic phenomena (in hands only) and motor sensitive peripheral polyneuropathy (affecting the lower limbs symmetrically). Low concentrations of blood cholinesterases confirmed the etiology. Myotonic phenomena disappeared spontaneously 6 months after the initial observation. One year later, the concentration of erythrocyte acetylcholinesterase was found to be low and plasma cholinesterase was normal, suggesting that the patient was carrier of a congenital deficiency of acetylcholinesterase. In literature relationship between myotonia and intoxication due to organophosphorus was not found. The whole clinical picture, cholinergic symptoms, transitory phenomena and spontaneous motor activity could be explained by an excess of acetylcholine. Electromyography (EMG) in the first observation showed neuromuscular transmission blocking characterized by deficiency or absence of voluntary activity, unexcitability of fibular nerves, with fibrillations and positive peaks as described previously with Mipafox (another organophosphorus agent). During 2 years of observation numerous end-plates potentials of muscular fibres persisted in the EMG. A progressive increase in voluntary activity showed by unit motor potential of almost normal amplitude and very increased duration was observed. No potentials of reinnervation were noted. The results of EMG were explained as disturbances of neuromuscular transmission associated with moderate signs of denervation. The Eaton-Lambert's test and the stimulation of a single unit motor potential confirmed disorder of neuromuscular synapses. The histochemistry of brachial biceps showed scattered atrophic and angulated type I and II fibres. Teased-fibres preparations showed nerve fibres with B, C, and G alterations as defined by Dyck et al. indicating axonal degeneration. These results were according to velocity of sensitive conduction. The conduction velocity of fibular nerves was strongly delayed during all the evolution indicating serious disorders of motor nerves myelin.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholine↗