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Biomedical subjects

A Sesso

Publications and source records attributed to A Sesso.

86 records · Page 5Linked to original sources
PubMedDate not supplied

The ultrastructural and histophotometric study of elastic and collagen fibers in type II Ehlers-Danlos syndrome and subclinical forms.

Skin disorders in type II Ehlers-Danlos Syndrome (EDS) are characterized by signs of cutaneous hyperdistensibility, skin and vascular fragility, atrophic scars, and articular hypermobility. These features may have less important clinical presentation in the intermediate forms of type II EDS. The authors studied the ultrastructural and quantitative aspects of elastic and collagen fibers in the skin of individuals with subclinical signs of type II of Ehlers-Danlos Syndrome. A group of 27 individuals (Group I) with large atrophic scars, articular hypermobility of the hands, and cutaneous and vascular fragility were compared with 10 healthy individuals. The subjects from both groups were volunteers from Hospital das Clínicas da Universidade de São Paulo. The elastic fibers did not show alterations but collagen ultrastructural abnormalities were seen in diameter and curvature, such as torsion, collagen flower-like aspect and discrete mass enlargement by histophotometry.

Collagen↗
PubMedDate not supplied

Defective proximal tubule lysosomal acidification by Bence Jones proteins. An immunoelectron microscopy study.

Proximal tubule handling of two human Bence Jones proteins (neutral and acidic BJP) was evaluated using protein A-gold labelling. After 30 min of acute light-chain infusion into 6 rats (alone or in combination with dinitrophenyl-aminopropyl-methylamine [DAMP]), kidney biopsies were processed for immunoelectron microscopy. Antibodies directed at monoclonal lambda light chains, mannose-6-phosphate cation-independent receptor (MPR) and DAMP were used. Labelling density (number of pA-gold particles/micrometer2), expressed as median (25-75 percentiles), differed (p < 0.05) between the two BJP, being 94.5 (32.9-212.5) vs. 19.4 (3.7-45.6) pA-gold/ micrometer2++ in endocytic vacuoles, and 297.3 (207.1-382.1) vs. 83.2 (16. 6-197.0) pA-gold/ micrometer2 in non-vacuolar electrondense endosome-lysosome structures. Labelling density for MPR was 47.7 (22. 2-84.6) vs. 4.0 (2.7-6.3) pA-gold/micrometer2. The area of MPR-labelled structures was also different, i.e.: 0.2 (0.1-0.4) vs. 0.9 (0.5-1.8) micrometer2. The endosome-lysosome pH distribution range differed significantly: 6.8 (6.4-7.0) vs. 6.3 (5.8-7.0). There was a significant accumulation of neutral BJP in endocytic structures, an acidification deficit of pre-lysosomes/lysosomes and MPR retention, suggestive of defective receptor recycling with this BJP. Interference with the physiological process of lysosomal acidification may be an important mechanism of higher nephrotoxicity in some BJP.

Acids↗
PubMedDate not supplied

In vitro action of some disinfectants on Paracoccidioides brasiliensis yeast forms.

The fungicidal action of sodium hypochlorite (0.3, 1, 2.5, 5 and 10%); formaldehyde (2, 5, and 10%); and ethyl alcohol (70%) on yeast forms of Paracoccidioides brasiliensis Pb 18 and a newly-isolated Goiana strain was described. Contact between the fungus and the disinfectants was maintained for 1, 2, 24, 48 and 72 hours at room temperature. Viability was evaluated by the fluorescein diacetate-ethidium bromide treatment, culture in solid and liquid media (36 degrees C and 26 degrees C); yeast to mycelial germination at room temperature; and radiometric study of metabolic activity. All concentrations of disinfectants were found to be effective in inactivating Pb 18 and Goiana strains, except for the 1-hour contact with 2% formaldehyde, in which fluorescein diacetate-ethidium bromide treatment was found to reveal 40 and 27% of viable cells, respectively. The yeast to mycelial germination method was considered to reveal faster and similar results as compared to culture in solid and liquid media.

Ethanol↗
PubMedDate not supplied

Acid secretory response in the late follow-up of proximal gastric vagotomy for duodenal ulcer without Helicobacter pylori eradication.

BACKGROUND/AIMS: The profile of acid secretory responses was studied in 20 patients who had had proximal gastric vagotomy (PGV) surgery performed 11-22 years previously in order to treat duodenal ulcers (DU). The presence of Helicobacter pylori was detected in all of the patients. METHODOLOGY: The recurrence of DU was diagnosed in 10 patients and the other 10 remained without recurrence during the follow-up period. The control groups included 10 DU patients with refractory responses to H2 receptor antagonists and 10 "normal" subjects. Both control groups had untreated Helicobacter pylori infection. Measures of 1) basal acid output, 2) acid output for 30 min under continuous i.v. infusion of 0.2 ug/kg/h of pentagastrin acid, and 3) the response for 30 and 60 min after starting a sham feeding, modified by the "chew and spit" technique under simultaneous i.v. infusion of 0.2 ug/kg/h of pentagastrin were performed. Serum gastrin was measured during fasting and at sham feeding. The densities of the gastrin cells of antrum and duodenum were estimated by morphometric counting. RESULTS: Both basal output and acid response to sham feeding plus pentagastrin infusion were higher in the DU controls and DU recurrence patients. The response to pentagastrin infusion did not show any discriminant value. Fasting serum gastrin values increased after PGV, either with or without DU recurrence. Gastrin cell hyperplasia was not demonstrated in any of these groups. CONCLUSIONS: The secretory profile of patients with both late DU recurrence after PGV and Helicobacter pylori infection lies between DU patients refractory to the H2 receptor antagonist approach and those free of DU recurrence after PGV--both of them with current Helicobacter pylori infection. The characteristic pattern of late DU recurrence after PGV and untreated Helicobacter infection is that of increased basal acid output and higher acid secretion responsiveness to sham feeding plus pentagastrin in the presence of higher serum levels of gastrin.

Adult↗
PubMedDate not supplied

In vitro cytochemical studies of the golgi apparatus of pancreatic acinar cells exposed to drugs that inhibit the transport of membranes and proteins.

In a preceding article, we described alterations occurring in rat pancreas acinar cells at successive post-mortem (PM) intervals. In ultra-thin sections from samples obtained from 0.5, 1, 2, 4, 8 and 12 h, we observed in the Golgi apparatus the appearance of an anomalous membrane bound structure. Such structures are formed by tubules and vesicles that we have called tubular vesicular structure (TVS), and they are frequently located in the position corresponding to the 4th cisterna of the Golgian cisternal pile. Lobules of rat pancreas, incubated in vitro with metabolic inhibitors (such as antimycin A, sodium fluoride, sodium azide and potassium cyanide), were processed in order to be compared with the PM samples of the rat acinar cells. In sliced pieces of lobules, acid phosphatase (AcPase) and tiaminopirophosphatase (TPPase) activity were evaluated. Except for the potassium cyanide treatment, we frequently observed the TVS located at the position corresponding to the 4th cisternae (similar to those observed in the PM acinar cells). These TVS's are predominantly TPPase positive. Based on this result and the fact that the TVS's are surrounded by a membrane (as confirmed by the freeze-fracture replica results) with no structural elements inside, they seem not to correspond to autophagosomes. The TVS's, observed either at PM consecutive times or incubated with metabolic inhibitors, seem to be structures formed in response to ATP deprivation. In 0,5 h PM cells and in cells incubated for 30 and 60 min with metabolic inhibitors, the subcellular structures reacted for AcPase in the rigid lamellae, CV and lysosomes.

Acid Phosphatase↗
PubMedDate not supplied

Long-term stability of lipid emulsions with parenteral nutrition solutions.

The stability of the mixture of peripheral vein parenteral nutrition (PN) solution with 10% lipid emulsions (Intralipid or Lipofundin MCT) was tested during a prolonged period of refrigerated storage. The analysis included gross visual examination of the bottle, pH determination, and examination by electron microscope. The mixtures of fat emulsions with PN solution demonstrated no physical instability or pH alteration. Examination under electron microscope revealed no alterations after 4 wk, but the surface layer of fat globules was disrupted after 10 and 18 wk. This study demonstrates that complete nutritive mixtures can be prepared and stored in refrigeration for at least 4 wk before clinical use.

Drug Stability↗
PubMedDate not supplied

[Stability of the mixture of a new fat emulsion with parenteral nutrition solutions].

The stability of the mixture of various parenteral nutrition (PN) solutions with a new fat emulsion containing 50% soybean oil and 50% medium chain triglycerides (MCT) was tested. Five different mixtures were analyzed under transmission electron microscopy 24 hours after the preparation: 1) 10% fat emulsion (FE); 2) FE + PN solution with 5% glucose; 3) FE + PN solution with 12.5% glucose; 4) FE + PN solution with 25% glucose; 5) FE + pure 50% glucose. The pH of each PN solution, fat emulsion and mixture was determined in order to verify if the stability was dependent on the pH of the surrounding medium. The mixture of lipid emulsion with PN solutions did not cause any coalescence of the liposomes or damage to their membranes. However, the addition of 50% glucose to FE coalesced the liposomes, probably due to a decreased pH of the medium (pH = 3.3). We conclude that mixtures of this specific lipid emulsion with PN solutions containing glucose up to 25% are stable for at least 24 hours, and suitable for clinical use in parenteral nutrition.

Drug Combinations↗
PubMedDate not supplied

Necrotizing lesions in Sjögren's syndrome. II. An electron microscopic study.

Further evidences about necrotizing lesions in Sjögren's syndrome are presented. Electron microscopic studies disclosed acinar replacement by a mucus-containing lake surrounded by remnant myoepithelial cells. Interepithelial lymphocytes infiltrate the acinar walls in adjacent areas and macrophages bearing mucoid material within cytopasmic vacuoles were found in the interstitium. The significance of these findings in the natural history of Sjögren's syndrome is discussed.

Humans↗