STUDIES ON SUSTAINED CONTRACEPTIVE EFFECTS WITH SUBCUTANEOUS POLYDIMETHYLSILOXANE IMPLANTS

1973 ◽  
Vol 73 (2) ◽  
pp. 347-359 ◽  
Author(s):  
G. Benagiano ◽  
M. Ermini ◽  
L. Carenza ◽  
P. Donini
Keyword(s):  
Urinary Excretion ◽  
Young Women ◽  
Ovarian Function ◽  
Megestrol Acetate ◽  
Bleeding Pattern ◽  
Experimental Conditions ◽  
The Third ◽  
Before And After

ABSTRACT Ovarian function was assessed in 10 healthy young women, before and after the insertion of 3 or 4 polydimethylsiloxane capsules filled with 20 mg of megestrol acetate. Each capsule released in vitro, approximately 20 μg/24 h of the hormone. Daily determination of the urinary excretion of FSH, LH, fractionated oestrogens and pregnanediol were performed in all subjects during one control cycle, the first and the third cycle after the insertion of the capsules. Out of 10, 8 control cycles were ovulatory according to all the parameters investigated. This compares with 15 ovulatory cycles out of a total of 20, examined after the insertion of the capsules. During treatment no changes were observed in the FSH excretion pattern; the mid-cycle LH peak was present in all ovulatory cycles, although it was usually much less evident under the action of megestrol acetate. The excretion of oestradiol was significantly increased in all subjects (P < 0.05) during the first cycle following implantation. Oestrone and oestriol excretion was also generally higher in patients bearing PDS capsules; however, this difference was not statistically significant. Pregnanediol levels were not affected by the treatment in all cycles considered to be ovulatory on the basis of all the parameters. The menstrual bleeding pattern did not change in the majority of cases. One patient had, during treatment with 3 capsules, two profuse break-through bleedings whereas another one became amenorrhoic two months after the insertion of 4 implants. It is concluded that megestrol acetate sustained release preparations do not inhibit ovulation under the experimental conditions used.

DETERMINATION OF BLOOD CORTICOIDS USING THE IN VITRO RESIN UPTAKE OF 3H-PREDNISOLONE

1968 ◽  
Vol 57 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Hironori Nakajima ◽  
Mitsunori Murala ◽  
Masumitsu Nakata ◽  
Takeshi Naruse ◽  
Seiji Kubo
Keyword(s):  
Thyroid Function Test ◽  
Normal Subjects ◽  
Adrenal Function ◽  
Function Test ◽  
Before And After ◽  
Adrenal Response ◽  
Suppression Test

ABSTRACT The in vitro resin uptake of 3H-prednisolone was used for the determination of blood cortisol after addition of radioactive prednisolone followed by Amberlite CG 400 Type 1 to the test serum, and incubation of the mixture. The radioactivity of the supernatant was compared before and after the addition of the resin. The principle of this method is similar to that of the 131I-triiodothyronine resin uptake for the thyroid function test. The tests for the specificity, reproducibility and sensitivity gave satisfactory results. The mean basal value ± SD of the 3H-prednisolone resin uptake was 35.3 ± 9.2% in normal subjects, and 27.1 ± 4.8% in pregnant women. This method was valid in various adrenal function tests, i. e. the adrenal circadian rhythm, corticotrophin (ACTH) test, dexamethasone suppression test and the adrenal response to lysine-8-vasopressin. It proved to be a sensitive indicator of the adrenal function. These results suggest that this method should be useful for a routine adrenal function test.

Factors affecting in vitro and in vivo antioxidant effects. Experimental conditions and nature of oxidants determine antioxidant efficacy

2021 ◽  
pp. 1-9
Author(s):  
Etsuo Niki
Keyword(s):  
Biological Molecules ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Beneficial Effects ◽  
Multiple Oxidants ◽  
Antioxidant Effects

Reactive oxygen and nitrogen species have been implicated in the onset and progression of various diseases and the role of antioxidants in the maintenance of health and prevention of diseases has received much attention. The action and effect of antioxidants have been studied extensively under different reaction conditions in multiple media. The antioxidant effects are determined by many factors. This review aims to discuss several important issues that should be considered for determination of experimental conditions and interpretation of experimental results in order to understand the beneficial effects and limit of antioxidants against detrimental oxidation of biological molecules. Emphasis was laid on cell culture experiments and effects of diversity of multiple oxidants on antioxidant efficacy.

EFFECTS OF FRESH PLASMA OR WHOLE BLOOD TRANSFUSIONS ON PATIENTS WITH VARIOUS TYPES OF MUCOPOLYSACCHARIDOSIS

PEDIATRICS ◽  
1972 ◽  
Vol 50 (5) ◽  
pp. 688-692
Author(s):  
Anatole S. Dekaban ◽  
Kenton R. Holden ◽  
George Constantopoulos
Keyword(s):  
Molecular Weight ◽  
Weight Distribution ◽  
Whole Blood ◽  
Blood Transfusions ◽  
Molecular Weights ◽  
The Third ◽  
Clinical Observations ◽  
Before And After ◽  
Fresh Plasma

Repeated fresh plasma or whole blood transfusions were given to five patients with either Hurler, Hunter, or Sanfilippo types of mucopolysaccharidosis. Clinical observations and total 24-hour urinary AMPS and their composition and molecular weight distribution were determined before, during, and after transfusions. The two patients who received plasma transfusions showed no noticeable change in the amount of AMPS excreted; of the three patients who received whole blood transfusions, two had slightly less excretion of AMPS while the third showed no difference. The AMPS in the CSF were measured in one patient before and after blood transfusions and found to be unchanged; likewise, the determination of molecular weights in the isolated AMPS was virtually identical. In the patients studied, the transfusions caused no demonstrable difference in the patients' clinical condition.

THE USE OF POLYSTYRENE–ALLERGEN CONJUGATES FOR THE REMOVAL OF ANTIBODIES FROM SERA OF ALLERGIC INDIVIDUALS

1960 ◽  
Vol 38 (1) ◽  
pp. 1249-1253
Author(s):  
L. Gyenes ◽  
A. H. Sehon
Keyword(s):  
Hydrochloric Acid ◽  
Protein Concentration ◽  
Complete Removal ◽  
Experimental Conditions ◽  
Comparative Analyses ◽  
Before And After

Polystyrene–ragweed conjugates were shown to remove specifically antibodies from sera of individuals allergic to ragweed. This observation is considered evidence that firm combination occurs in vitro between allergic antibodies and the homologous allergens. Comparative analyses of allergic sera before and after exposure to immunosorbents indicated that complete removal of skin-sensitizing, blocking, and hemagglutinating antibodies did not result in a measurable decrease in protein concentration, thus demonstrating that these factors are present only in minute amounts.Attempts to eîute allergic antibodies from the homologous immunosorbents under various experimental conditions did not lead to their recovery in significant yields; these antibodies could be recovered in small amounts by dissociation with hydrochloric acid at pH 3.

Effects of hypoxia and ischemia on autoregulation in postnatal intestine

1991 ◽  
Vol 261 (1) ◽  
pp. G152-G157 ◽  
Author(s):  
P. T. Nowicki ◽  
C. E. Miller ◽  
R. C. Edwards
Keyword(s):  
Blood Flow ◽  
Pressure Reduction ◽  
Experimental Conditions ◽  
Hypoxic Conditions ◽  
Significant Relationships ◽  
Norepinephrine Infusion ◽  
Before And After ◽  
Age Appropriate ◽  
Arterial Po2

Pressure-flow autoregulation was quantified within in vitro intestine from 3- and 35-day-old swine before and after lowering arterial PO2 (hypoxia) or lowering baseline blood flow by means of norepinephrine infusion (ischemia). Autoregulation was elicited by reducing arterial pressure approximately 33% from an age-appropriate baseline pressure. In 3-day-old intestine, autoregulation was unaffected by hypoxia or ischemia: vascular resistance was unchanged after pressure reduction, while Gf averaged -0.33 +/- 0.15 vs. -0.26 +/- 0.05 under control vs. hypoxic conditions, and -0.48 +/- 0.15 vs. -0.46 +/- 0.11 under control vs. ischemic conditions, respectively. In 35-day-old intestine, autoregulation was enhanced by hypoxia and ischemia. Under both experimental conditions, vasodilation was noted in response to pressure reduction: Gf averaged -0.04 +/- 0.14 vs. 0.38 +/- 0.08 under control vs. hypoxic conditions, and -0.12 +/- 0.10 vs. 0.28 +/- 0.08 under control vs. ischemic conditions, respectively. Regression analysis revealed a significant inverse linear correlation between Gf and venous PO2 in older, but not younger, subjects. Significant relationships between Gf and blood flow were not demonstrated in either group under any experimental condition. We conclude that autoregulation is enhanced within in vitro intestine from 35-, but not 3-day-old, swine during hypoxia or ischemia, and that reduction of venous PO2 is the principal factor responsible for the effect noted in older subjects.

scholarly journals DETERMINATION OF l-HISTIDINE IN NANOGRAM AMOUNTS AND THE QUESTION OF ITS OCCURRENCE IN MAST CELLS

1972 ◽  
Vol 20 (11) ◽  
pp. 917-922 ◽  
Author(s):  
DAVID I. WILKINSON ◽  
DAVID GLICK
Keyword(s):  
Mast Cells ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Peritoneal Mast Cells ◽  
Before And After ◽  
Chromatographic Detection ◽  
Rat Peritoneal Mast Cells ◽  
Rate Limiting

In an attempt to clarify the question of whether histidine is stored in the mast cell for coversion to histamine or whether the rate of conversion is rapid enough to prevent accumulation of histidine so that the rate-limiting step is the histidine uptake, it was found that no histidine was demonstrable in rat peritoneal mast cells by either quantitative analysis or paper chromatographic detection. Microadaptation of Hassall's method, based on conversion of l-histidine by histidase to urocanic acid and measurement of the latter by its absorbance at 277 nm, was made to permit determination of histidine in nanogram amounts in the presence of histamine. This adaptation was found reliable when compared with the o-phthalaldehyde method in estimation of l-histidine in serum and in insulin hydrolysate, and then it was applied to analysis of mast cells before and after l-histidine uptake in vitro. The adaptation should be generally useful in microanalysis of l-histidine in histologically and cytologically defined samples.

Remineralization Potential of a New Toothpaste Formulation: An In-Vitro Study

2004 ◽  
Vol 5 (1) ◽  
pp. 18-30 ◽  
Author(s):  
Carlos A. Muñoz ◽  
Anna Torrado ◽  
Manuel Valiente ◽  
Wu Zhang ◽  
Yiming Li
Keyword(s):  
Ion Exchange ◽  
In Vitro Study ◽  
Ion Exchange Resin ◽  
Ion Exchange Resins ◽  
Experimental Conditions ◽  
Human Enamel ◽  
Before And After ◽  
Ph Cycling ◽  
Exchange Resins

Abstract The aim of the present study was to determine the ability of a dentifrice containing a mixture of ion-exchange resins (named NMTD), which supplies calcium, fluoride, phosphate, and zinc ions, to promote remineralization and/or inhibit demineralization of dental human enamel in a pH cycling model in vitro. A fluoride toothpaste was used as the control. The enamel specimens were tested for microhardness before and after 10 days and 16 days of the demineralizing and remineralizing treatments. The results of this study showed both dentifrices were effective in limiting in vitro enamel demineralization although the effects were not significantly different from each other. Inclusion of calcium and phosphate ion-exchange resins in the dentifrice containing a fluoride ion-exchange resin maintained a similar net outcome of the conventional dentifrice in the demineralization/ remineralization process under the experimental conditions employed. Citation Torrado A, Valiente M, Zhang W, et. al. Remineralization Potential of a New Toothpaste Formulation: An In-Vitro Study. J Contemp Dent Pract 2004 February;(5)1:018-030.

scholarly journals Hot-Stage Microscopy for Determination of API Particles in a Formulated Tablet

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Michal Šimek ◽  
Veronika Grünwaldová ◽  
Bohumil Kratochvíl
Keyword(s):  
Active Pharmaceutical Ingredient ◽  
Assessment Method ◽  
Hot Stage Microscopy ◽  
Tablet Disintegration ◽  
Before And After ◽  
In Vitro Assessment ◽  
Active Substances ◽  
Good Agreement

Although methods exist to readily determine the particle size distribution (PSD) of an active pharmaceutical ingredient (API) before its formulation into a final product, the primary challenge is to develop a method to determine the PSD of APIs in a finished tablet. To address the limitations of existing PSD methods, we used hot-stage microscopy to observe tablet disintegration during temperature change and, thus, reveal the API particles in a tablet. Both mechanical and liquid disintegration were evaluated after we had identified optimum milling time for mechanical disintegration and optimum volume of water for liquid disintegration. In each case, hot-stage micrographs, taken before and after the API melting point, were compared with image analysis software to obtain the PSDs. Then, the PSDs of the APIs from the disintegrated tablets were compared with the PSDs of raw APIs. Good agreement was obtained, thereby confirming the robustness of our methodology. The availability of such a method equips pharmaceutical scientists with an in vitro assessment method that will more reliably determine the PSD of active substances in finished tablets.

STUDIES ON SUSTAINED CONTRACEPTIVE EFFECTS WITH SUBCUTANEOUS POLYDIMETHYLSILOXANE IMPLANTS

1973 ◽  
Vol 73 (2) ◽  
pp. 360-373 ◽  
Author(s):  
M. Ermini ◽  
F. Carpino ◽  
M. Russo ◽  
G. Benagiano
Keyword(s):  
Foreign Body ◽  
Subcutaneous Tissue ◽  
Giant Cells ◽  
The Other ◽  
Megestrol Acetate ◽  
Body Type ◽  
Fibrotic Tissue ◽  
Before And After ◽  
One Year

ABSTRACT In vitro diffusion of [14C] megestrol acetate (MA) was studied before and after the subcutaneous insertion of polydimethylsiloxane implants (PDS) in the human. A certain period of equilibration before diffusion becomes constant is required for newly prepared capsules as well as for those extracted from the subcutaneous tissue within six months of the insertion. On the other hand, in vitro diffusion from capsules that have remained in the human for periods over one year, does not require any equilibration. Up to six months, the release in vitro of megestrol acetate was not significantly changed, whereas it was greatly decreased when capsules were re-incubated following sojourn in the subcutaneous tissue for 18 or 24 months. A continuous wall of newly formed fibrotic tissue, proliferated in a circular manner was found around the capsules in all the cases studied. This fibrillary tissue was then surrounded by a fibrous adipose layer containing granulomas and giant-cells of the foreign body type.

scholarly journals Evaluation of physicochemical and antioxidant properties of nanosized copolymeric micelles loaded with kaempferol

Pharmacia ◽  
2020 ◽  
Vol 67 (2) ◽  
pp. 49-54
Author(s):  
Krassimira Yoncheva ◽  
Nadia Hristova-Avakumova ◽  
Vera Hadjimitova ◽  
Trayko Traykov ◽  
Petar Petrov
Keyword(s):  
Antioxidant Activity ◽  
Propylene Oxide ◽  
Encapsulation Efficiency ◽  
Antioxidant Properties ◽  
In Vitro Release ◽  
Before And After ◽  
Poly Propylene ◽  
Vitro Release

The study was focused on the evaluation of two copolymers as micellar carriers for kaempferol delivery. The copolymers comprised identical hydrophilic blocks of poly(2-(dimethylamino)ethyl methacrylate and different hydrophobic blocks of either poly(ε-caprolactone) (PDMAEMA9-b-PCL70-b-PDMAEMA9) or poly(propylene oxide) (PDMAEMA13-b-PPO69-b-PDMAEMA13). The calculation of Flory-Huggins parameters and determination of encapsulation efficiency showed that PDMAEMA-b-PCL-b-PDMAEMA copolymer possessed higher capacity for kaempferol loading. The diameter of the micelles before and after lyophilization was not changed, suggesting that the micelles could be lyophilized and redispersed before administration. The in vitro release of kaempferol from PDMAEMA-b-PPO-b-PDMAEMA micelles was faster than the release from PDMAEMA-b-PCL-b-PDMAEMA micelles, probably due to the higher affinity of kaempferol to this copolymer. Further, the higher affinity resulted in a retention of antioxidant activity of kaempferol in the presence of DPPH and KO2 radicals. Thus, PDMAEMA-PCL-PDMAEMA was considered more appropriate carrier because of the higher encapsulation efficiency and preservation of antioxidant activity of the drug.

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