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J Salcedo

Publications and source records attributed to J Salcedo.

At least 19 recordsLinked to original sources
PubMed1990

A study of the electrokinetic and stability properties of nitrofurantoin suspensions. I: Electrokinetics.

An experimental investigation is described of the electrokinetic properties of nitrofurantoin. The experiments are based on measurements of electrophoretic mobility in suspensions of this drug and the calculation of its zeta potential (zeta) following two different procedures. A simple mechanism is proposed for explaining the sign of the surface charge of nitrofurantoin and its increase with the pH of the medium. The effect on zeta of changes in the concentration of NaCl, CaCl2, or AlCl3 is studied for different pH values of the suspensions. The behavior of zeta in the presence of NaCl shows evidence of Cl- adsorption on the particles, especially at low electrolyte concentrations. The AlCl3 salt was capable of reversing the sign of the surface charge, changing it to positive when a given, pH-dependent concentration was added to the suspension. The effect of this salt on zeta for different pH values was probably due to the hydrolysis of the cation Al3+. A significant increase of the negative surface charge was observed when a small amount (0.1%) of a synthetic polymer, Carbopol 934, was present in NaCl or AlCl3 systems. This appears to indicate that the large polymer molecules adsorb on nitrofurantoin particles as part of their stabilizing mechanism.

Acrylic Resins↗
PubMed1990

Electrophoretic study of nitrofurantoin in aqueous suspensions. Effect of the addition of a polymeric thickener.

The electrophoretic mobility of nitrofurantoin (based on the microelectrophoresis method) has been studied in dilute dispersions of the drug. Specifically, the effect of NaCl, CaCl2 and AlCl3, pH, and a thickener, Carbopol 934, was determined. The electrophoretic mobility (mu) increases in absolute terms when the pH is raised between 3 and 9, although mu remains negative in this pH range. The variation of absolute mobility ([mu[) with NaCl concentration shows a pronounced maximum for a concentration of about 10(-4) M. However, when the concentration of CaCl2 in the medium is increased, [mu[ decreases steadily. The effect of AlCl3 concentration on the mobility is markedly influenced by the pH of the dispersing medium although a general trend is observed for mu to become more positive with increasing concentration of the salt. Finally, Carbopol 934 appears to impart an extra negative charge to the nitrofurantoin surface, since higher negative mobilities were measured in the presence of the polymer.

Acrylic Resins↗
PubMed1987

Shigellosis at a Caribbean resort. Hamburger and North American origin as risk factors.

During a three-week period in 1984, 339 tourists and expatriate employees with diarrhea visited the infirmary at a Caribbean resort club. Epidemiologic studies suggested that over 60% of the 1,893 tourists at the resort club during that time may have been ill. Shigella flexneri 4a was isolated from seven of 18 stool specimens. A few cases of diarrheal illness occurred at the resort club before the onset of the outbreak, which was temporally related to illness in a butcher. North American residence, eating raw or very rare hamburger, having a roommate who was ill and younger age were significantly associated with acquiring disease. Control measures, principally elimination of ill food handlers from the kitchens, were followed by a prompt and marked reduction in new cases. Isolated resorts pose problems in disease control similar to those on cruise ships, with hundreds of foods available, large numbers of short-stay visitors with few outside exposures, and many food handlers in whom pathogens can persist between groups of visitors. Resort clubs can reduce the risk of traveler's diarrhea, without using mass prophylaxis against pathogenic bacteria, by appropriate handling and preparation of food and by surveillance for diarrheal illnesses.

Adult↗
PubMed1976

Recovery from inhalation of diquat aerosol.

A patient developed high fever, cough, changing consolidations on chest roentgenograms, jaundice, and skin rash following inhalation of diquat aerosol. To our knowledge this is the first report of diquat inhalation and only the second report of aerosol damage from any part of the dipyridyl herbicides.

Accidents, Home↗
PubMed1965

Road to progress.

Explore the source record for details and available documents.

Philippines↗
PubMedDate not supplied

Evolution of membranous nephropathy from a proliferative and exudative glomerulonephritis--a report of three cases studied by serial biopsies.

Three adolescents with clinical nephrotic-nephritic picture were noted to have diffuse proliferative and exudative glomerulonephritis. Although focal membranous changes were noted in two of the initial biopsies, evolution into classical membranous glomerulopathy was seen in subsequent biopsies. This study suggests a relationship between these two different patterns of immune complex-associated glomerular injury, and confirms extrapolations made from experimental models of chronic serum sickness.

Biopsy↗