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E Martin

Publications and source records attributed to E Martin.

At least 631 records · Page 35Linked to original sources
PubMed1982

[Contribution to the stability of tropicamide solutions (author's transl)].

The course of the degradation of tropicamide solutions was elucidated. Thus, inter alia, intramolecular elimination of water leads to a compound comparable to apoatropine that the authors designated by atropicamide. Furthermore, methods are described that permit (after thin-layer chromatographic repartition) to detect and to determine quantitatively the active principle in the presence of its degradation products. Tropicamide is stable in aqueous solution; eye-drops prepared from such a solution (Mydrum) are stable for no less than 5 years.

Chemistry, Pharmaceutical↗
PubMed1982

[On the stability of phenylmercury salts. Part 50: Contributions to problems concerning the use of plastic receptacles for liquid pharmaceuticals (author's transl)].

The authors describe a dithizone method for the determination of phenylmercury salts that yields easily reproducible results on examining the stability of these preserving agents. Aqueous solutions of phenylmercury salts are instable already in glass bottles, but they are instable to a much greater extent in low-density polyethylene bottles. Their degradation is accelerated in the presence of chloride ions. When stored under nitrogen, the phenylmercury salt solutions show lower losses of preserving agents than when stored under normal air. The ultra-violet extinction of phenylmercury salt solutions increases during storage in glass bottles, and decreases during storage in plastic bottles. In plastic bottles, the degradation is associated with sorption.

Chemical Phenomena↗
PubMed1982

[Role of the thickness of the graft in osteocartilaginous autotransplantation in the rabbit knee].

This experimental study is complementary to the clinical series of cartilaginous autografts in the knee for medial condylar necrosis. The aim was to determine the viability of the articular cartilage in a series of grafts with variable thickness of the underlying spongy bone. The study was done on 36 adult rabbits and the cartilage was studied by biochemical, histochemical and ultrastructural methods. The results are conclusive. The earliest abnormal signs in the first few weeks affect the thinnest grafts of 4 mm whereas the 12 mm thickness grafts hardly show any lesions. It is therefore possible to use large autogenic grafts for osteocartilaginous defects provided the proportion between the area of the articular surface and the underlying spongy bone of the graft is at least 1/4. Under these circumstances, cartilaginous deterioration will be avoided and reduce long term degeneration.

Animals↗
PubMed1982

[Stability of cyclodrin hydrochloride. 3: Stability of cyclodrin hydrochloride as a substance and in ophthalmologic solutions. 51: Contributions to problems concerning the use of plastic receptacles for liquid pharmaceuticals].

The authors deal with the stability of cyclodrin hydrochloride. A reference sample of solid cyclodrin hydrochloride stored for four and a half years showed 0.4-0.6% degradation. A storage stability of five years is considered justifiable. In eye-drops the stability of this active agent is determined by the pH value. Unbuffered eye-drops (optimized formula) are considerably more stable than the buffered solutions hitherto used. Unbuffered eye-drops contained in glass bottles as well as in plastic bottles should be stable for 2-3 years.

Drug Packaging↗
PubMed1981

Intestinal M3 antigen, a marker for the intestinal-type differentiation of gastric carcinomas.

The mucus-associated intestinal M3 antigen, normally restricted to intestinal goblet cells, was found in 35 out of 100 gastric adenocarcinomas belonging to intestinal (19/64) as well as diffuse (16/36) types according to Laurén's classification. often accompanying the other mucus-associated gastric M1 and M2 antigens. This M3 antigen was predominant over the gastric M antigens in 25 of these 35 tumors; 18 of these belonged to the histological intestinal type. According to the WHO classification, the M3 antigen was found to predominate in all mucinous adenocarcinomas (7/7), was never present in the undifferentiated carcinomas (0/8), but was also found in some tubulo-papillar (16/57) and signet-ring cell (12/27) adenocarcinomas. This antigen could be used as a new criterion and incorporated into a point system containing morphological and tumor cell behavioral considerations; then it would appear to be a good marker for intestinal-type differentiation. Indeed, 22 of these 25 gastric adenocarcinomas which produced predominantly M3 antigen showed such an intestinal-like differentiation. The M antigen pattern of gastric carcinoma suggested a duodenal rather than colonic-type differentiation.

Adenocarcinoma↗
PubMed1981

[The effect of the gas permeability of plastics on the stability of thiomersal. Part 49: Contributions to problems concerning the use of plastic receptacles for liquid pharmaceuticals (author's transl)].

Our studies have shown that the considerable losses of Thiomersal contained in low-density polyethylene bottles are not attributable, as suggested in the literature, to a sorption of this preserving agent. Intact Thiomersal is not sorbed by low-density polyethylene; on the contrary, the good permeability of this packing material to gas, especially oxygen, accelerates the degradation of Thiomersal. Furthermore, the ethylmercury resulting from this degradation is able to permeate through low-density polyethylene by which a displacement of the reaction equilibrium takes place in favour of the degradation products, and the degradation of Thiomersal is accelerated. The mechanism of the degradation of Thiomersal in the presence of oxygen was elucidated.

Drug Packaging↗
PubMed1981

Carcinoid tumor of the common bile duct.

The fifth case of a common bile duct carcinoid tumor is reported. The importance of endoscopic retrograde cholangiography on the one hand and specialized staining on the other for diagnosis is emphasized. The slow growing nature of these tumors favors extensive surgery whenever possible.

Adult↗
PubMed1980

Additional component required for activity and reconstitution of light-activated vertebrate photoreceptor GTPase.

A light-activated GTPase that functions as a component of the rhodopsin-linked, light-activated phosphodiesterase (PDEase) system in vertebrate photoreceptors has been reported. In our efforts to purify photoreceptor GTPase we encountered another component (which we call "helper" or "H" component) whose presence is required for expression of light-activated GTPase activity. We report here the characterization of this heat-labile, macromolecular factor and that the presence of helper is absolutely required for light- and rhodopsin-dependent activation of photoreceptor GTPase. Of equal importance, we find that the "G" component (which requires the presence of H for expression of GTPase activity) can bind GTP and can support light- and GTP-dependent PDEase activation in the absence of H component. These data support a model in which GTP binding to G component is a necessary condition for PDEase activation. Hydrolysis of GTP at the G activator locus (an H-dependent activity) is a regulatory event which reverses PDEase activation. The complexity of this regulatory mechanism provides opportunities for signal modulation and amplification.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1980

Predictability of phenytoin serum levels by nomograms and clinicians.

On the basis of a reliable steady state phenytoin serum concentration on one (lower) dose, the serum concentration on a second (higher) dose was predicted in 28 patients (32 levels) by two previously reported nomograms and 3 physicians who had clinical experience with phenytoin therapy. Both nomograms and all 3 physicians on the average underestimated the serum concentration on the higher dose. Except for 1 physician, this bias was statistically significant (p < 0.05). The mean and SD of the prediction errors (difference between predicted and measured serum concentration) were -2.2 +/- 4.2 and -3.1 +/- 3.6 for the two nomograms and -1.0 +/- 4.0, -2.1 +/- 4.1 and -1.8 +/- 4.2 for the 3 physicians, respectively. Thus, independent of the method used, there was a large uncertainty in the prediction; the approximate 68% confidence interval of the prediction error (mean +/- SD) was almost as large as the therapeutic range of the drug. Because prediction of phenytoin serum levels based on one serum concentration measurement was found unreliable in this study, it is proposed that every patient whose dose had been increased should be under close observation until a new steady state has been confirmed.

Adult↗
PubMed1980

Quantification of antibodies against factor VIII by an immunonephelometric method in a continuous-flow system.

A new immunonephelometric method is described for the quantification of antibodies against factor VIII in sera from patients suffering from haemophilia A. We have been able to reduce the reaction time to only 16 minutes, which permits its application to emergency cases. Applying Spearman's test, we have correlated the results obtained by the immunonephelometric and Ruggieri's methods, obtaining r = 0.87, P < 0.01 for n = 11. From the reproducibility studies we obtained SD = 1.16 as maximum dispersion value. Because it is a fully automated method in a continuous-flow system, the possible manual errors are reduced to a minimum; 60 determinations can be carried out in 1 hour.

Antibodies↗