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Biomedical subjects

R Campos

Publications and source records attributed to R Campos.

At least 91 records · Page 5Linked to original sources
PubMed1986

Fatal encephalopathy due to Lagochilascaris minor infection.

A 14-year-old boy with a tetralogy of Fallot showed a subacute, progressive encephalopathy characterized by headache, stupor and coma. Death occurred three months after the beginning of the illness. Neuropathologic examination revealed diffuse foci of necrosis of the cerebral hemispheres and cerebellum, and the presence of the nematode Lagochilascaris minor in the parenchyma and in the cisterns at the base of the brain. In almost all 28 cases of human lagochilascaris previously reported, the worms were located in the soft tissues of the neck and throat, tonsils, mastoids and paranasal sinuses. This is the first reported case in which Lagochilascaris infected the brain. Since the life cycle of the worm is unknown the pathogenesis of the central nervous system lesions is obscure.

Adolescent↗
PubMed1985

The effect of polyamines on tubulin assembly.

The assembly of cold solubilized microtubules prepared from calf brain and the polymerization of tubulin purified from this material are facilitated by polyamines at physiological concentrations. The number of free amino groups in the polyamine determines the ability of the polyamines to promote microtubule formation. Spermine with four amino groups was the most effective polyamine tested. Spermidine and N'-acetylspermine with 3 amino groups were less effective than spermine but more effective than N8-acetylspermidine and putrescine which contain two free amino groups. Microtubule formation may therefore be controlled by alterations in the nature and amounts of polyamines present.

Animals↗
PubMed1985

Early steps in FMDV replication: further analysis on the effects of chloroquine.

We have previously demonstrated that chloroquine and NH4Cl, two well-known lysosomotropic drugs inhibit foot-and-mouth disease virus (FMDV) replication. This fact points to the relevance of an acidic environment during FMDV penetration. In the present report, we show that chloroquine prevents the cell-mediated disruption of 140 S virions into 12 S particles. This dissociation, which resembles that caused by low pH in vitro, might be an initial uncoating step. Furthermore, we demonstrated that a decrease in the environmental pH counteracts the effect of chloroquine indicating that viral disruption is a low-pH cell-mediated process. The fact that it still occurs at low temperature (20 degrees) and shortly after viral adsorption suggests not only that prelysosomal vesicles represent the putative site for uncoating but also cause the virion to uncoat.

Animals↗
PubMed1984

Further evaluation of the SG test strip for estimation of urinary osmolality.

The mass densities of 2000 urines from children and 2000 urines from adults were determined with the new test strip, Multistix SG, and the results were compared with osmolality measurements. Normal urinary parameters were investigated for possible interference with the test strip reading. Variations in the pH and ionic composition of urine considerably influenced the test strip reading, whereas nonionic compounds, such as glucose and urea, showed practically no interference. For patients on a normal diet and without metabolic diseases, the new test strip is more appropriate than urometry for the determination of the mass density of the urine.

Adult↗
PubMed1984

[Dermatophytosis caused by Aphanoascus fulvescens].

Aphanoascus fulvescens was isolated from lesions resembling a dermatophyte infection in a 45-year-old woman who had used steroid cream for several months to treat a dermatosis of the neck. Treatment with griseofulvin and tolnaftate cured the lesions in 6 weeks. The microscopic characteristics of the isolate and its size differed slightly from those described by several other authors, and bore a closer resemblance to isolates previously described from Australia and New Guinea.

Ascomycota↗
PubMed1982

[Early stages in the replication of aphthous fever virus. Kinetics of partial degradation and sites for the establishment of penetrating residual virus].

At input multiplicities between 5-10 UFP/cell FMDV O1 Caseros adsorb in BHK21 Clon 13 cells at a rate of 5-20% depending whether cells are in suspension or in monolayers. At least four washings with medium are required to eliminate non specifically adsorbed virions. The remaining attached virus appears to be in contact with "specific" receptors of the cytoplasmic membrane. After penetration, 80% of virus became degraded to slow molecular weight material which is detected at first in the subcellular fraction and is gradually excreted out of the cells. The degradation process occurs from 0 to 15 minutes and it is demonstrated by a parallel decrease in infectivity and stability of purified labelled FMDV O1 Caseros. The 20% remaining virus is found firmly attached to a subcellular fraction precipitable at 15,000 xg. Parental residual infectivity remains remarkably stable for 90 min at which time newly synthetized RNA appears. Fraction of 15,000 xg from infected cultures was obtained at 60 min PI and incubated in vitro at 37 C. The infectivity remains unaltered for a period of 120 min even if the preparation is treated with 0.2% of triton x 100. Fraction of 15,000 xg from infected and control cultures obtained at different time PI were seeded on a linear sucrose gradient. A sharp peak of acid phosphatase associated with the lower mobility bands indicates the presence of intact lysosome structures. A shoulder of the enzyme activity is detected between the two main protein bands. Associated with the region rich in unbroken lysosomes, a very sharp peak of infectivity and/or 3H uridine or 32P labelled incoming virus can be detected. A different pattern of the residual incoming infectivity is found associated with the more rapid sedimentation protein band. 3H uridine incorporation at the beginning of viral RNA synthesis initiation shows that an important amount of newly synthesized viral RNA is found in the lower mobility band of the 15,000 xg fraction. Some incorporation is also detected in the faster band. The results presented here suggest that some functional activity is associated with the residual virus present at the beginning of infection in the 15,000 xg fraction. It can also be accepted that this virus penetrates by pinocytosis of specific receptors at the cytoplasmic membrane.

Animals↗
PubMed1982

Nodular regenerative hyperplasia of the liver. Report of two cases associated with autoimmune disease.

Nodular regenerative hyperplasia of the liver (N.R.H.) is an uncommon clinicopathological entity characterized by diffuse regenerative hepatocytic nodules without fibrosis. Grossly the lesion is often mistaken for cirrhosis. The etiology and pathogenesis are unknown. We report two new cases of N.R.H. diagnosed by liver biopsy. Peritoneoscopically the liver showed a nodular surface resembling micronodular cirrhosis. Both patients showed some clinical and immunological features of autoimmune disease, and in both cases N.R.H. was associated with chronic active hepatitis. We discuss the pathological differential diagnosis of N.R.H., its relation to other associated diseases and review the hypotheses for the pathogenesis of this condition.

Aged↗
PubMed1979

[Metabolic regulation of nutrition].

The mechanisms regulating nutrient metabolism and their adaptation and compensation during stress conditions are discussed. The stress conditions considered are fasting and refeeding, pregnancy, growth and development, and malnutrition.

Carbohydrate Metabolism↗