Long-acting antibacterial agents

1970 ◽  
Vol 8 (26) ◽  
pp. 101-103
Keyword(s):  
Plasma Proteins ◽  
Antibacterial Agents ◽  
Renal Excretion ◽  
Slow Release ◽  
Blood Levels ◽  
Prolonged Action ◽  
Procaine Penicillin ◽  
High Doses ◽  
Long Acting ◽  
Release Form

A number of antibacterial agents have recently been developed which are recommended because they need to be administered infrequently. Examples are Deteclo (Lederle), Kelfizine W (Pharmitalia), and Vibramycin (Pfizer). The advantage claimed for these preparations is that adequate blood levels can be maintained with infrequent dosage. A prolonged action may be achieved in various ways - for example, by using a mixture of antibiotics which are absorbed and excreted at different rates, as in Deteclo;1 by giving high doses of a well absorbed preparation which is slowly excreted, e. g. doxycycline (Vibramycin),2 by administration in a slow-release form, e. g. procaine penicillin; or by giving probenecid to lessen renal excretion. Where prolongation of action depends on increased binding to plasma proteins, the drug may be more likely to act as a hapten and so to induce allergic reactions.

Hormonal regulation of ascorbic acid in the adrenal of the rat

1985 ◽  
Vol 109 (3) ◽  
pp. 393-402 ◽  
Author(s):  
G. A. Overbeek
Keyword(s):  
Growth Hormone ◽  
Ascorbic Acid ◽  
Hormonal Regulation ◽  
Blood Levels ◽  
High Dose ◽  
Low Doses ◽  
Acth Level ◽  
Low Levels ◽  
High Doses ◽  
Long Acting

Abstract. Fifteen days after hypophysectomy of rats the concentrations of ascorbic acid (AA) in adrenals, liver, blood and urine are lower than in normal rats or in rats 1 day after hypophysectomy. Despite the low levels the percentage AA depletion after administration of ACTH and the subsequent repletion to the pre-ACTH level are normal. Lack of corticosteroids is not the cause of the low AA levels, as shown by experiments in 15 days adrenalectomized rats and in rats treated with low doses of dexamethasone. Fifteen days treatment with high doses of dexamethasone lowered the AA concentrations in adrenals, liver and blood. Treatment with long-acting ACTH maintained adrenal weight but not adrenal and blood AA. A high dose of ACTH lowered these levels. The administration of AA markedly increased the AA levels in blood, but did not normalize its concentration in the adrenals, not even when the size of the adrenals was maintained by treatment with long-acting ACTH. Growth hormone, in particular when administered together with long-acting ACTH, markedly raised the AA concentration in the adrenals but hardly affected the AA blood level. Rats with high blood levels of prolactin induced by pituitary grafts in the kidney also had clearly higher AA levels in adrenals, but not in blood. These results indicate that, although acute AA release from the adrenal is caused by ACTH, AA uptake to a certain concentration is not controlled by the pituitary gland, and above this concentration is promoted by growth hormone and prolactin. In the liver AA release may also be caused by ACTH but the AA production is promoted by other as yet unidentified pituitary factors.

Effects of Vancomycin on Platelets, Plasma Proteins and Hepatitis B Surface Antigen

1975 ◽  
Vol 34 (01) ◽  
pp. 083-093 ◽  
Author(s):  
Barry S Coller ◽  
W. B Lundberg ◽  
Harvey R Gralnick
Keyword(s):  
Hepatitis B ◽  
Factor Viii ◽  
Surface Antigen ◽  
Plasma Proteins ◽  
Hepatitis B Surface Antigen ◽  
Infusion Site ◽  
Vancomycin Therapy ◽  
Intravenous Injections ◽  
Low Concentrations ◽  
High Doses

SummaryThe antibiotic vancomycin shares many similarities with ristocetin, an agent noted for its effects on platelets and plasma fibrinogen. Vancomycin did not aggregate platelets as ristocetin, but platelets were incorporated into precipitates induced by vancomycin. Fibrinogen and factor VIII were precipitated from plasma at low concentrations of vancomycin. The precipitated fibrinogen remained clottable. Hepatitis B surface antigen was selectively precipitated from serum and could be recovered from the precipitate. Rabbits receiving bolus intravenous injections of high doses of vancomycin developed hypofibrinogenemia and thrombocytopenia within minutes and often went on to die. Studies with 125I-vancomycin revealed little stable binding of the antibiotic to platelets or fibrinogen. A relationship is suggested between the potent protein precipitating effects and phlebitis at the infusion site commonly associated with vancomycin therapy.

CLINICAL INVESTIGATIONS OF A LONG-ACTING OESTRIOL (POLYOESTRIOL PHOSPHATE)

1961 ◽  
Vol 38 (1) ◽  
pp. 73-87 ◽  
Author(s):  
Christian Lauritzen ◽  
Semih Velibese
Keyword(s):  
Side Effects ◽  
Phosphoric Acid ◽  
Quantitative Data ◽  
Water Soluble ◽  
Cholesterol Concentration ◽  
Experimental Investigations ◽  
Clinical Investigations ◽  
Prolonged Duration ◽  
High Doses ◽  
Long Acting

ABSTRACT A description is given of experimental investigations and preliminary clinical experience with the long-acting oestriol compound polyoestriol phosphate – a water-soluble polymere of oestriol and phosphoric acid. The compound seems to exert all the physiologically important effects of oestriol. Even with high doses the hormone causes no proliferation of the endometrium and no withdrawal bleeding. It has no untoward effect on metabolism. It decreases slightly the cholesterol concentration (to the extent of ⅓–⅕ of the effect produced by long-acting oestradiol esters). The compound has a wide therapeutic range. No side-effects have been observed. Doses of 10 mg or more have a prolonged duration. Additional prolongation of the effect is largely dependent on dosage. To ensure an effect lasting for 4 weeks 40 mg polyoestriol phosphate (corresponding with 30 mg oestriol) is required – an amount which roughly corresponds with physiological quantitative data. The compound, which involves an interesting new principle of prolongation, was most effectively used in the treatment of menopausal symptoms and genital organic disorders. For these indications it can be recommended without reservation.

METABOLISM OF 17α-HYDROXYPROGESTERONE-4-14C-17α-CAPROATE BY HOMOGENATES OF RAT LIVER AND HUMAN PLACENTA

1961 ◽  
Vol 36 (4) ◽  
pp. 511-519 ◽  
Author(s):  
Margaret Wiener ◽  
Charles I. Lupa ◽  
E. Jürgen Plotz
Keyword(s):  
Rat Liver ◽  
Human Placenta ◽  
Steric Hindrance ◽  
Placental Tissue ◽  
Caproic Acid ◽  
Major Product ◽  
Side Chain ◽  
Anaerobic Conditions ◽  
Prolonged Action ◽  
Long Acting

ABSTRACT 17α-hydroxyprogesterone-4-14C-17α-caproate (HPC), a long-acting progestational agent, was incubated with homogenates of rat liver and human placenta. The rat liver was found to reduce Ring A of HPC under anaerobic conditions to form allopregnane-3β,17α-diol-20-one-17α-caproate and pregnane-3β,17α-diol-20-one-17α-caproate, the allopregnane isomer being the major product. The caproic acid ester was neither removed nor altered during the incubation. Placental tissue did not attack HPC under conditions where the 20-ketone of progesterone was reduced. It is postulated that this absence of attack on the side chain is due to steric hindrance from the caproate ester, and that this may account for the prolonged action of HPC.

scholarly journals Effects of Late Conversion from Twice-Daily to Once-Daily Slow Release Tacrolimus on the Insulin Resistance Indexes in Kidney Transplant Patients

2021 ◽  
Vol 2 (1) ◽  
pp. 49-56
Author(s):  
Valeria Cademartori ◽  
Fabio Massarino ◽  
Emanuele L. Parodi ◽  
Ernesto Paoletti ◽  
Rodolfo Russo ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Kidney Transplant ◽  
Slow Release ◽  
Density Lipoprotein ◽  
Blood Levels ◽  
Transplant Recipients ◽  
Once Daily ◽  
C Peptide ◽  
Transplant Patients ◽  
Kidney Transplant Patients

The use of tacrolimus (Tac) may be involved in the development of new-onset diabetes after transplantation (NODAT) in a dose-related manner. This study aimed to evaluate the effects of a standard twice-daily formulation of Tac (TacBID) vs. the once-daily slow-release formulation (TacOD) on the basal insulin resistance indexes (Homa and McAuley), and related metabolic parameters, in a cohort of kidney transplant patients. We retrospectively evaluated 20 stable renal transplant recipients who were switched from TacBID to TacOD. Blood levels of Tac were analyzed at one-month intervals from 6 months before to 8 months after conversion. Moreover, Homa and McAuley indexes, C-peptide, insulin, HbA1c, uric acid, triglycerides, low-density lipoprotein (LDL) and high-density lipoprotein (HDL)-cholesterol serum levels and their associations with Tac levels were evaluated. We observed a significant decrease in Tac exposure (8.5 ± 2 ng/mL, CV 0.23 vs. 6.1 ± 1.9 ng/mL, CV 0.31, TacBID vs. TacOD periods, p < 0.001) and no significant changes in Homa (1.42 ± 0.4 vs. 1.8 ± 0.7, p > 0.05) and McAuley indexes (7.12 ± 1 vs. 7.58 ± 1.4, p > 0.05). Similarly, blood levels of glucose, insulin, HbA1c, lipids, and uric acid were unchanged between the two periods, while C-peptide resulted significantly lower after conversion to TacOD. These data suggest that in kidney transplant recipients, reduced Tac exposure has no significant effects on basal insulin sensitivity indexes and metabolic parameters.

Rebound of aldosterone but not of corticosterone after suppression of adrenal function by triamcinolone acetonide in rats

1988 ◽  
Vol 75 (5) ◽  
pp. 551-557 ◽  
Author(s):  
Gabriele Meier
Keyword(s):  
Triamcinolone Acetonide ◽  
Renal Excretion ◽  
Statistical Significance ◽  
Plasma Aldosterone ◽  
Adrenal Function ◽  
Sensitive Period ◽  
Blood Levels ◽  
Corticoid Therapy ◽  
Rebound Phenomenon

1. The effects of microcrystalline ‘depot’ triamcinolone acetonide on renal excretion and blood levels of aldosterone, 18-hydroxycorticosterone and corticosterone were studied in rats over a 13 day period. The renal excretion of all of these steroids was found to be suppressed on day 1 after triamcinolone acetonide administration. Corticosterone excretion remained suppressed for 6 days, whereas aldosterone and 18-hydroxycorticosterone excretion normalized within 3 days. 2. While corticosterone excretion was returning to control values, the excretion of aldosterone rose to values above the pretreatment levels (the rebound phenomenon). 18-Hydroxycorticosterone excretion paralleled that of aldosterone, but the rebound was of less statistical significance. 3. The findings in urine were confirmed by plasma steroid determinations. A suppression of plasma aldosterone, 18-hydroxycorticosterone and corticosterone was observed in the first 24 h after triamcinolone acetonide injection. On day 4 only corticosterone showed lowered levels. An aldosterone rebound could be seen at 18.00 hours, the circadian maximum in rats. 4. These findings suggest that in addition to the effects on glucocorticoids, mineralocorticoids have to be taken into account in the restoration of the adrenal function after corticoid therapy. The aldosterone rebound observed during this sensitive period may be important in preventing disturbances of electrolyte and water homoeostasis.

scholarly journals The Roles of Dietary Glutamate in the Intestine

2018 ◽  
Vol 73 (Suppl. 5) ◽  
pp. 15-20 ◽  
Author(s):  
Daniel Tomé
Keyword(s):  
Monosodium Glutamate ◽  
Amino Acid Content ◽  
Intestinal Lumen ◽  
Free Form ◽  
Blood Levels ◽  
Umami Taste ◽  
Low Concentrations ◽  
Cephalic Phase ◽  
Gut Function ◽  
High Doses

Glutamate (Glu), either as one of the amino acids of protein or in free form, constitutes up to 8–10% of amino acid content in the human diet, with an intake of about 10–20 g/day in adults. In the intestine, postprandial luminal Glu concentrations can be of the order of mM and result in a high intra-mucosal Glu concentration. Glu absorbed from the intestinal lumen is for a large part metabolized by enterocytes in various pathways, including the production of energy to support intestinal motility and functions. Glu is the most important fuel for intestinal tissue, it is involved in gut protein metabolism and is the precursor of different important molecules produced within the intestinal mucosa (2-oxoglutarate, L-alanine, ornithine, arginine, proline, glutathione, γ-aminobutyric acid [GABA]). Studies in adult humans, pigs, piglets or preterm infants indicate that a large proportion of Glu is metabolized in the intestine, and that for the usual range of Glu dietary intake (bound Glu and free Glu including added Glu as a food additive in normal amounts up to 1 g/day), circulating Glu is tightly maintained at rather low concentrations. Systemic blood levels of Glu transiently rise when high doses monosodium glutamate (> 10–12 g), higher than normal human dietary consumption, are ingested and normalize within 2 h after the offset of consumption. Glu is also involved in oral and post oral nutrient chemosensing that involves gustatory nerves and both humoral and neural (vagal) gut-brain pathways with an impact on gut function and feeding behavior. Glu functions as a signaling molecule in the enteric nervous system and modulates neuroendocrine reflexes in the gastrointestinal tract. The oral taste sensation of Glu involves its binding to the oral umami taste receptors that triggers the cephalic phase response of digestion to prepare for food digestion. Glu is sensed again in the gut, inducing a visceral sensation that enhances additional gut digestive processes through the visceral sense (vago-vagal reflex).

ACTH-elicited sodium appetite in sheep

1980 ◽  
Vol 239 (1) ◽  
pp. E45-E50 ◽  
Author(s):  
R. S. Weisinger ◽  
J. P. Coghlan ◽  
D. A. Denton ◽  
J. S. Fan ◽  
S. Hatzikostas ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Steroid Hormone ◽  
Extracellular Fluid ◽  
Blood Levels ◽  
Adrenal Steroid ◽  
Sodium Appetite ◽  
Intramuscular Injections ◽  
Acth Treatment ◽  
Long Acting

Intramuscular injections of long-acting synthetic ACTH (45 U twice daily for 5 days) caused a large increase in the intake of 0.5 M NaCl in sheep. Mean Na intake of the sheep on the last 3 days of treatment approximated 50% of their total extracellular fluid Na. The mineral appetite was specific for NaCl. Intakes of 0.5 M KCl or 0.25 M CaCl2 were not significantly altered. The enhanced appetite for Na induced by ACTH appeared to precede any increase in urinary Na excretion. ACTH treatment was ineffective in adrenalectomized sheep. However, an infusion into adrenalectomized sheep of a combination of adrenal steroid hormones (including aldosterone, deoxycorticosterone, 11-deoxycortisol, cortisol, and corticosterone) that contrived blood levels similar to those, obtained with ACTH treatment in normal sheep did induce Na appetite. Thus, ACTH induces a specific, adrenal-steroid hormone-dependent Na appetite in sheep.

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