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Biomedical subjects

J Cardozo

Publications and source records attributed to J Cardozo.

At least 19 recordsLinked to original sources

Comparison of the genomes of two Xanthomonas pathogens with differing host specificities.

The genus Xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the Proteobacteria. Xanthomonas axonopodis pv. citri (Xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. Symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline. Xanthomonas campestris pv. campestris (Xcc) causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis. Xanthomonas campestris pv. campestris is grown commercially to produce the exopolysaccharide xanthan gum, which is used as a viscosifying and stabilizing agent in many industries. Here we report and compare the complete genome sequences of Xac and Xcc. Their distinct disease phenotypes and host ranges belie a high degree of similarity at the genomic level. More than 80% of genes are shared, and gene order is conserved along most of their respective chromosomes. We identified several groups of strain-specific genes, and on the basis of these groups we propose mechanisms that may explain the differing host specificities and pathogenic processes.

Gene Order↗

[Epidemiologic studies of cerebellopontine angle tumors surgically treated in Maracaibo, Venezuela, in 1985-1999].

OBJECTIVE: To analyze the epidemiological, clinical and neuropathological data of cases of cerebellopontine angle (CPA) tumors. MATERIAL AND METHODS: The clinical records, neuroimaging and neuropathological studies of 50 patients with diagnosis of CPA tumor operated in different hospitals of Maracaibo, Venezuela, during the lapse January 1st, 1985-December 31, 1999 were reviewed. The variables age, gender, side of the lesion and neuropathological diagnosis were analyzed. RESULTS: A 2:1 female to male ratio was observed. Median age was 48 +/- 12.7 years. Acoustic neuromas (AN) represented 48% of the cases, whereas nonacoustic neuroma tumors (NANT) made up for the rest (52%). Meningiomas were the second more commonly diagnosed lesions, they constituted 32% of the cases. Meningiomas and AN were more frequent in women, their ratios being 7:1 and 1.6:1, respectively. In 60% of the cases the signs and symptoms became eloquent in patients of the fourth and fifth decades of life. CONCLUSIONS: The difference between our results and the ones previously reported in the medical literature are due in part to the predominance of female patients in our series. Endocrinologic, genetic and biochemical factors could also be responsible; nevertheless, this does not constitute the objective of the present study.

Adult↗

Hallervorden-Spatz disease: two new early childhood onset cases.

Hallervorden-Spatz disease is a rare, autosomal-recessive hereditary condition characterized by early onset of progressive movement alterations such as dystonia, rigidity, and choreoathetosis, which is usually associated with pyramidal signs and mental deterioration. The authors report two cases for which diagnosis of Hallervorden-Spatz disease was based on clinical manifestations that appeared during the first year of life, illness progression, and late-stage magnetic resonance imaging findings. The possibility that these two cases, along with other previously described rare instances with similar clinical features, be considered as a variant of subtype of the early-onset type of Hallervorden-Spatz disease is suggested. The need to differentiate these cases from cases of static encephalopathy with mental retardation and motor impairment is also stressed.

Child↗

[Teratogenic effect of ammonium metavanadate in Swiss albino mice].

Far as it is known to us, there is only one report in the medical literature dealing with the teratogenous effect of vanadium on neural structures (1): while trying to experimentally induce anencephaly in the offsprings of swiss-albino mice through the administration of ammonium metavanadate via drinking water, during different stages of their lives; a neural tube defect consisting of arrhinencephaly was obtained; various degrees of hypoplasia or aplasia of both the olfactory bulbs and tracts were evidenced, as well as congenital lesions of variable intensity in other rhinencephalic structures. The probable mechanisms through which vanadium exercises its neural teratogenous effect are analyzed.

Anencephaly↗

[Central nervous system infection by free-living amebas: report of 3 Venezuelan cases].

INTRODUCTION: Infection of the Central Nervous System by free living amebas is an unusual event, 344 cases have been reported to date. The disease becomes evident in two different clinical fashions: Primary Amebic Meningoencephalitis (PAM) caused by Naegleria fowleri and Granulomatous Amebic Encephalitis (GAE) induced by Spp. of Acanthamoeba and Balamuthia. CLINICAL CASES: The authors report three new cases from Venezuela. Case 1. 34 years old man, with a chief complaint of general malaise, headache and fever, a diagnosis of common cold was made and the patient was treated as such, he did not improve and was admitted to the hospital with deterioration of his clinical status; the patient died 10 days after the onset of his illness which was determined to be GAE produced by Balamuthia mandrillaris. Case 2. 8 years old female admitted to the hospital because of fever, headache and generalized seizures of sudden onset; neurocysticercosis was diagnosed and following improvement the patient was discharged and readmitted on two occasions because of relapse and worsening of her illness, she died 2 months after the onset of her disease that was diagnosed by autopsy as GAE due to Balamuthia mandrillaris. Case 3. 16 years old male, previously healthy, who following immersion in a water tank was admitted to the hospital because of meningeal irritation that progressed to coma and death in a 7 day lapse; autopsy revealed PAM by Naegleria fowleri. The two cases of GAE due to Balamuthia mandrillaris occurred in apparently immunocompetent individuals, contrary to the statement that these microorganisms are opportunistic. CONCLUSION: We believe that neurological infection by amphizoic amebas is being underdiagnosed, probably due to ignorance regarding this pathology or because of a very low autopsy rate in most countries.

Adolescent↗

[Weight of the normal brain of the Venezuelan adult according to sex and age].

The weight of adult brains (age range: 19-100 years) obtained from 3967 consecutive necropsies performed over a period of ten years at the Hospital General del Sur of Maracaibo, are reviewed. The analysis of the weight of 1215 g in males, whereas the men brain weight in females was 1122 g. The encephalic weight decreases with age, diminishing rapidly after age 65 in males, and age 75 un females.

Adult↗

AT1 and TxA2/PGH2 receptors maintain hypertension throughout 2K,1C Goldblatt hypertension in the rat.

Angiotension II (ANG II) increases the generation of vasoconstrictor prostaglandin endoperoxides (PGH2) and thromboxane A2 (TxA2). Two-kidney, one-clip (2K,1C) Goldblatt hypertensive rats have an increased plasma renin activity (PRA) and ANG II level during the early, but not the late, phases of hypertension. Therefore, the aim of these studies was to compare the antihypertensive efficacy of an ANG II type I (AT1) and a TxA2/PGH2 receptor antagonist during different phases of 2K,1C hypertension. Rats were maintained on a fixed sodium intake for 3 days before and throughout the period of drug administration. These studies assessed the antihypertensive response to administration of the AT1 receptor antagonist losartan (20 mg.kg-1.day-1), the TxA2/PGH2 receptor antagonist ifetroban (20 mg.kg-1.day-1) or vehicle given for 3 days to rats with early (2-4 wk postclip), intermediate (10-12 wk postclip), and late (36-42 wk post-clip) 2K,1C hypertension and to two control groups of rats corresponding in age to the early or intermediate and the late 2K,1C groups. The mean arterial pressure (MAP) was measured directly with indwelling arterial cannulas. The MAP of sham-operated rats was 109 +/- 5 mmHg. In the early phase of 2K,1C hypertension, the MAP was increased to 143 +/- 6 mmHg, and it was increased further to 162 +/- 5 mmHg during the intermediate and to 179 +/- 4 mmHg during the late phase. The PRA, compared with age-matched controls, was increased during early and intermediate, but not late phase 2K,1C hypertension. Neither drug lowered blood pressure in control rats. However, both drugs significantly reduced the blood pressure in the early, intermediate, and late phases of 2K, 1C hypertension. At the end of 3 days of administration, blood pressure in early 2K, 1C rats given losartan was reduced to levels of control rats, but remained slightly elevated in other groups and in those receiving ifetroban. In conclusion, AT1 and TxA2/PGH2 receptors maintain hypertension throughout the evolution of 2K, 1C hypertension in the rat, despite changes in PRA.

Angiotensin Receptor Antagonists↗

[Intraventricular oligodendroglioma. Description of 2 cases].

Oligodendrogliomas usually arise in the cerebral hemispheres, less frequently they are found in the cerebellar hemispheres and very rarely they adopt an intraventricular location. The authors describe two cases of intraventricular oligodendroglioma. Case No. 1: 18-year old woman with a clinical history of headache, vertigo and dizziness of 6 months duration. Central Nervous System imaging revealed a right lateral ventricle tumor. Case No. 2: 38 year old man with a chief complaint of positional headache and visual impairment. C.N.S. imaging showed a third ventricular lesion. The medical literature was reviewed and theories on the genesis of this peculiar location are offered.

Adolescent↗

[Extramedullary intracranial solitary plasmocytoma. Report of 2 cases].

Multiple myeloma frequently affects the C.N.S with a high prevalence of spinal cord compression following vertebral neoplastic infiltration. On the other hand, solitary plasmacytomas, tumors that arise in a wide variety of locations due to the universal distribution of plasma cells, are infrequent within the cranial vault and rarely present as extramedullary lesions, arising from the intracranial soft tissues without affecting neighboring bony structures. Only 33 such cases have been reported in the medical literature. The authors report two additional cases of solitary intracranial, extramedullary plasmacytoma. Case 1.--54 year-old woman with a chief complaint of severe headache and behavioral changes of three months duration. C.N.S. imaging revealed a bifrontal mass lesion, arising from the anterior third of the falx cerebri. Case 2.--45 year old-man who complained of headache and blurred vision of a month duration C.N.S. imaging displayed a third ventricle mass lesion. In both cases the neuropathological diagnosis was extramedullary plasmacytoma. Postoperatively the confirmation of solitary intracranial plasmacytoma was achieved only after a thorough work-up to rule out the presence of neoplasm elsewhere in the body. Radiotherapy was given to both patients and follow-up has failed to reveal neoplastic disease 4 and 3 years, respectively, after the diagnosis.

Brain Neoplasms↗

Comparison of hemp and cotton fiber implants in muscle rat tissue. Study of the inflammatory response.

Hemp fiber is obtained from the plant Musa textilis. The cost of preparation of its raw fibers is low. The purpose of this paper was to compare the inflammatory response in the rat muscle tissue originated by both hemp and cotton fibers. Both types of fibers, were implanted in gluteal muscles of Sprague Dawley rats. The rats were sacrificed at 15, 30 and 60 postoperative days. Muscle tissue sections were stained with hematoxilyneosin. The inflammatory response was measured by subtracting the suture surface area from the total granulomatous area. At 15 days, the inflammatory response was more conspicuous for hemp than for cotton fiber (P < 0.05). At 30 and 60 days, responses were similar (P > 0.05). We cannot conclude that the hemp fiber is superior to cotton, nevertheless, they behave the same. Therefore, hemp constitutes an alternative as suture material.

Animals↗

[A leiomyosarcoma of vascular origin. A case report].

Leiomyosarcomas arising from the wall of the blood vessels, are highly malignant tumours. Although 75% of the cases have been reported in the inferior vena cava, nevertheless scanty mention is made in the literature of an analogous tumor originating from smaller blood vessels. This paper deals with a 53-year-old man with a tumor in the right axilla. Surgery consisted in wide local excision. Histopathology revealed a mesenchymal tumor in an axillary blood vessel. Electron microscopy revealed tumor cell with all the characteristics of a leiomyosarcoma. The patient refused adjuvant therapy and died 10 months later with local recurrence and lung metastases.

Axilla↗

The Peutz-Jeghers syndrome. Case reports.

Two additional cases of Peutz-Jeghers syndrome are described. One of them, a 19 year-old female, is a sporadic case, whereas in the other case, also a 19 year-old female, there are two members of the family with the Peutz-Jeghers syndrome. A review of some salient features of this entity is made. These include clinical presentation, histopathological features, malignant potential and treatment.

Adult↗

[Single diverticulum of perforated cecum. Report of 5 cases].

Cecal diverticulitis is a relatively rare disease, which closely mimics the picture of acute appendicitis. At times it is difficult to differentiate from carcinoma. Five cases of cecal diverticulitis are reported, with a discussion of some salient features of this condition. Although two cases were treated with a right hemicolectomy, a plea for conservatism in the treatment of this disease is made.

Adult↗

[Granular cell tumor of the vulva].

Granular cell tumor is a relatively uncommon entity of unknown etiology and uncertain histogenesis. A case of granular cell tumor of the vulva is presented with a discussion of the clinical features, pathological characteristics and the histogenic theories of its origin.

Adult↗

Choroid plexus papilloma containing bone.

The presence of bone in choroid plexus papillomas is a rare event. The authors report a case of choroid plexus papilloma of the IVth ventricle containing bone in a 18-year-old man, and review two previously reported cases, as well as the mechanisms proposed for the presence of bone and cartilage in neuroepithelial neoplasms.

Adolescent↗

[Causes of dementia in Maracaibo, Venezuela: a re-evaluation].

INTRODUCTION AND OBJECTIVES: In a previous report we analyzed the causes of dementia in an autopsy population from four hospitals of Maracaibo, Venezuela. Our results showed that vascular dementia (VD) accounted for 86.7% of all clinically diagnosed demented patients, whereas no cases of Alzheimer's disease (AD) were neuropathologically demonstrated. Six years later, we undertook a similar study, in order to re-evaluate the frequency of the different causes of dementia in our country. MATERIAL AND METHODS: We studied 611 adult brains obtained from autopsies performed during the period 1992-1998; 39 of these came from clinically demented patients. RESULTS: Vascular dementia was disclosed in 33 cases (84.6%), five cases (12.82%) showed evidence of specific causes for dementia other than VD or AD, and in one of the cases (2.56%) the neuropathological changes were specific for AD. CONCLUSIONS: Our current results confirm the conclusions of our previous study and contrast with the vast majority of reports in the medical literature regarding the frequency of the different causes of dementia, except for studies from China, Japan and Russia that yielded similar findings as ours. At present, further investigations are being undertaken in order to come up with possible explanations for these differences.

Adult↗