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Biomedical subjects

J Lim

Publications and source records attributed to J Lim.

241 records · Page 14Linked to original sources
PubMedDate not supplied

The pharmacokinetics of ceftibuten in humans.

The pharmacokinetics of ceftibuten, a new oral cephalosporin, has been studied in humans. Ceftibuten is very well absorbed in young and old patients. Absorption may be slightly decreased by food or relatively high doses (800 mg). The pharmacokinetics have been well characterized in rising single-dose and multiple-dose studies. The half-life is relatively long for this class of drugs, being approximately 2-3 hr. Apparent plasma clearance (CL/F), is approximately 40-75 ml/min, and the renal clearance is approximately 30-50 ml/min, corresponding to the fraction excreted unchanged in the urine of approximately 60%-70% of the dose. The apparent volume of distribution after oral dosing (Vd/F) was approximately 0.2 L/kg. The half-life, plasma clearance, renal clearance, and fraction excreted in urine are not affected by increasing dose and are constant during multiple dosing. There is little drug accumulation during multiple dosing. Drug elimination is decreased in patients with renal insufficiency and dosing in these patients should be adjusted relative to creatinine clearance values. The drug penetrates very well to experimentally induced inflammatory fluid but produces negligible levels in breast milk. The drug has no effect on the pharmacokinetics of theophylline. The drug is well tolerated and has pharmacokinetic properties that are clinically advantageous.

Absorption↗
PubMedDate not supplied

Comparative bioavailability of ceftibuten in capsule and suspension forms.

The comparative bioavailability of ceftibuten, a new third-generation cephalosporin antibiotic given orally once daily, in capsule and suspension dosage forms, was assessed in healthy male subjects. In three separate studies, subjects received either a 400-mg dose as a suspension or one laboratory-batch, 400-mg capsule; one laboratory-batch, 400-mg capsule or two laboratory-batch, 200-mg capsules; or one production-batch, 400-mg capsule or two laboratory-batch, 200-mg capsules. Plasma samples were assayed for ceftibuten using high-performance liquid chromatography, and the data were assessed using pharmacokinetic and statistical methods. Confidence intervals for the maximum plasma concentration and the area under the plasma concentration-time curve extrapolated to infinity were within 80% to 125% of guidelines, demonstrating the bioequivalence of the two treatments within each of the three studies. One 400-mg capsule (laboratory or production batch) was bioequivalent to two 200-mg capsules used in a clinical efficacy trial; the 400-mg suspension was bioequivalent to a 400-mg capsule (laboratory batch). Thus we concluded that the capsule and the suspension dosage forms were bioequivalent.

Administration, Oral↗
PubMedDate not supplied

Effect of local corticosteroids on early inflammatory function in surgical wound of rats.

To investigate the effects of local corticosteroids during the early inflammatory process in iatrogenically induced surgical wounds, three different types of corticosteroids, dexamethasone sodium phosphate (Decadron), betamethasone sodium phosphate (Celestone Phosphate), and betamethasone sodium phosphate-acetate (Celestone Soluspan), were evaluated using rats. Single doses of corticosteroid were administered locally to male Sprague-Dawley rats after the surgical implantation of a wound chamber, which was used to collect fluid from the surrounding surgical wound. Wound fluids were drawn from the wound chamber at postoperative days 1, 3, and 5 and analyzed for total white blood cells (WBCs) and differential count. In this study, the authors have demonstrated that the corticosteroids (dexamethasone sodium phosphate, betamethasone sodium phosphate, betamethasone sodium phosphate-acetate) cause at least 50% reduction in the total circulating WBCs at the surgical wound site on postoperative day 1, followed by decreased reductions on days 3 and 5.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Noninvasive imaging of the superficial femoral artery using ultrasound Duplex scanning.

A total of 56 lower extremities in 28 patients were evaluated by both conventional arteriography and ultrasound duplex scanning. Overall sensitivity for duplex scanning compared to arteriography in detecting stenotic or occlusive disease was 91%, specificity was 94%, positive predictive value 85% and negative predictive value 97%. Results for Duplex scanning were better in the proximal and middle segment compared to the distal third of the superficial femoral artery. The sensitivity of segmental lower extremity pressures and pulse volume recordings for predicting proximal superficial femoral artery disease compared to arteriography was 82%; specificity was 79% and accuracy 80%, all inferior to that of Duplex scanning. Duplex scanning is a promising technique suitable for noninvasive assessment of patients presenting with suspected superficial femoral artery disease. It should readily identify candidates for percutaneous interventional techniques in which a patent segment of proximal superficial femoral artery is required for access. It will also be useful in follow-up studies of patency of the superficial femoral artery following interventional procedures such as balloon dilatation and laser angioplasty.

Aged↗
PubMedDate not supplied

Absorption, metabolism, and excretion of 14C-tosifen in the dog and rat.

14C-tosifen [N-2-(1-phenylpropyl)-N'-p-tolyl sulfonylurea] was readily absorbed in both rats and dogs. The rates of absorption, metabolism, and urinary excretion were higher in the rat than in the dog. More of the drug was excreted via the feces than in the urine of the rat, whereas in the dog, the drug was primarily excreted into the urine. The parent drug was the major radioactive component in the plasma of both species. In the urine, however, only a negligible amount of tosifen was found. The major urinary metabolite was a hydroxymethyl derivative which accounted for about 60% and 40% of the total radioactivity in the urine of the dog and rat, respectively.

Absorption↗
PubMedDate not supplied

Morphological alterations in the lymphoreticular system in acquired immunodeficiency syndrome.

Acquired immunodeficiency syndrome (AIDS) manifests a profound deficiency in cellular and humoral immunity causing opportunistic infections with high mortality. Intensive searching for accurate diagnosis, effective treatment, and reliable preventions are in progress. Diagnostic findings include lymphocytopenia, decreased T-helper/T-suppressor ratio and antibodies against human T-lymphotropic retrovirus-III. Specific morphological markers for the diagnosis of AIDS are not yet available at this time. Consistent findings in the lymphoreticular system include a reactive hyperplasia in the onset to lymphocyte depletion in it's advance stage. The frequently mentioned ultrastructural changes in lymphoreticular cells are tubulo-reticular structures, test tube and ring-shaped forms, multivesicular and virus-like particles. These are, however, nonspecific for the diagnosis of AIDS.

Acquired Immunodeficiency Syndrome↗