[Pleurodesis with tetracycline hydrochloride]

Malignant pleural effusion is a common complication of malignant disease requiring drainage and palliative sclerosing therapy in the vast majority of cases. Tetracycline in conjunction with thoracoscopic drainage is currently considered as the optimal sclerosing agent due to its high efficacy, good patient tolerance, simple and repeatable applicability and low cost of treatment. Traditional and more recent agents like fibrin-sealant may give similar results, but do not achieve a favourable all-round-properties. The relevant data from the literature are reviewed, our own results are presented. An explicit description of pleurodesis is given, also a brief discussion of possible mechanisms of action of sclerosing agents. Concepts are suggested for positioning pleurodesis in the general therapeutic approach to various tumours. The concept of pleurodesis can be similarly successful and safely applied on malignant pericardial effusion (pericardesis).

[Diagnostic thoracoscopy in mediastinal space-occupying lesions]

Thoracoscopy is a helpful and safe procedure for diagnosing a variety of mediastinal masses if adequate information cannot be obtained out due to biological risk or patient non-compliance. An explicit description of thoracoscopic technique is given along with case reports demonstrating the efficiency of the method.

[Pleurodesis with tetracycline hydrochloride in spontaneous pneumothorax]

Treatment of spontaneous pneumothorax aims at avoiding relapses besides achieving immediate reexpansion of the lung. Thoracoscopy should definitely occupy a well-established position in the diagnostic and therapeutic step-by-step schedule. On the one hand, it enables local treatment methods, and on the other it helps in arriving at a decision with regard to the operation. If conditions permit, pleurodesis should be effected via the intrapleural rubber-tube drain, tetracycline hydrochloride having proved very suitable for this purpose. A retrospective review is given on the experiences with thoracoscopy and pleurodesis on the basis of own cases.

The role of computerized modeling and simulation in the development of life support system technologies

Using conventional means of process development, it would take decades and hundreds of millions of dollars to develop technology for recycling of water and solid waste for lunar missions within the next thirty years. Since we anticipate neither that amount of time nor level of funding, new methodologies for developing life support systems (LSS) technologies are essential. Computerized modeling and simulation (CMAS) is a tool that can greatly reduce both the time and cost of technology development. By CMAS, we refer to computer methods for correlating, storing and retrieving property data for chemical species and for solving the phenomenological equations of physical/chemical processes (i.e., process conditions based on properties of materials and mass and energy balances, equipment sizing based on rate processes and the governing equations for unit operations). In particular, CMAS systems can be used to evaluate a LSS process design with minimal requirements for laboratory experimentation. A CMAS model using ASPEN PLUS is presented for a vapor compression distillation (VCD) system designed for reclaiming water from urine.

Cluster headache-like headaches: a symptomatic feature? A report of three patients with intracranial pathologic findings

This report concerns three patients with cluster headache-like headaches associated with intracranial pathologic findings. The question whether the occurrence of cluster headache-like headaches may be a symptomatic feature is still not solved. In two of the three presented cases the cluster headache-like headaches disappeared when the intracranial abnormalities were treated.

[New methods in the radiotherapy of bronchial carcinoma. Endobronchial small-field irradiation using the iridium-129 high-dose afterloading technic in combination with the neodymium-YAG laser]

106 patients with inoperable malignant tumours constricting the central bronchial tree underwent endobronchial small-field radiotherapy with iridium-192 at high dose between June 1983 and September 1985. Treatment was performed using the computer-guided after-loading technique and a flexible bronchoscope under local anaesthesia. In complete occlusion of a bronchus by the tumour, a neodymium YAG-laser was applied (57 patients) to allow insertion of the after-loading probe. Endoscopy showed tumour regression in 75% of the patients, accompanied by clinical improvement. Pulmonary function tests, arterial blood gas analyses and pulmonary perfusion scans yielded a highly significant improvement of data after treatment. The procedure also proved effective upon exhaustion of external radiation. Apart from its positive palliation, endobronchial small-field radiotherapy using high doses of iridium-192 also has a curative effect, thus opening up a new approach to the therapy of advanced bronchial carcinoma.

Prostaglandins and thromboxane: tert.-butyldimethylsilyl ethers as derivatives for their analyses by gas chromatography-mass spectrometry-selected ion monitoring

tert.-Butyldimethylsilyl ethers of eighteen prostaglandins (PGs) and thromboxane have been analyzed by combined packed-column or fused-silica capillary gas chromatography-mass spectrometry (GC-MS). Except for thromboxane B2 and PGs of the 3 series the [M - 57] ion, the loss from the molecular ion of the tert.-butyl radical, is generally the major peak in the spectra of PGs. This high abundance of large fragments provides suitable criteria for the employment of these derivatives in GC-MS selected ion monitoring for rapid quantity estimation of PGs from biological samples. PGs from rat stomach fundus were rapidly quantitated in a single chromatogram using this procedure.

Determination of prostaglandins and thromboxane as their pentafluorobenzyl-trimethylsilyl derivatives by electron-capture gas chromatography

The optimization of the parameters affecting the chromatographic properties and separation of prostaglandin pentafluorobenzyl derivatives by gas chromatography using electron-capture detection is described. The effects of composition and flow-rate of carrier gas, temperatures of detector and column, and nature of stationary phases on the detector response to different pentafluorobenzyl (both oxime and ester) trimethylsilyl ether derivatives of prostaglandins were systemically examined. The stability of some selected prostaglandin derivatives at -20 degrees C was also determined. After standardizing these parameters, prostaglandins and related compounds from biological samples, e.g. semen, rat aorta, dog serum and trout gill were successfully analyzed. Identification of prostaglandins was confirmed by gas chromatography-mass spectrometry.

Dietary trilinoelaidate: effects on metabolic parameters related to EFA metabolism in rats

To study the effects of dietary trilinoelaidate (tt18:2) on metabolic parameters, as they relate to essential fatty acid metabolism, a diet containing "adequate" linoleic acid with incremental isocaloric ttl8:2 supplementation was formulated. This diet was fed to rats for 11 weeks and oxygen (O2) consumption, insensible water loss (IWL), growth parameters and liver fatty acid composition evaluated at specified time intervals. The results showed that while an essential fatty acid deficient diet (hydrogenated tallow) increased IWL and decreased body weight gains, O2 consumption remained unaltered. Dietary tt18:2, while accumulating in liver lipids, apparently inhibiting delta 6 desaturase, as evidenced by 18.2/20.4 ratios, did not alter O2 consumption of IWL. At the highest level of tt18:2 fed (2.5 weight percent of dietary fat) there was a noticeable decrease in body weight gains by the 11th week; organ weights, however, were not affected. While the increased consumption of dietary trans fatty acids has raised questions regarding their potential biologically detrimental effects, the present study indicated that gross metabolic alterations related to classical essential fatty acid deficiency symptoms are not precipitated in the rat by tt18:2 levels comparable to those consumed in a normal human diet.

Extraction and purification of prostaglandins and thromboxane from biological samples for gas chromatographic analysis

An efficient extraction procedure for the isolation of prostaglandins (PGs) from biological samples for their subsequent quantification by gas chromatography-electron capture detection (GC-ECD) is described. PGs were extracted from lung, kidney, spleen and stomach fundus into ethyl acetate at different pHs. The highest recovery and least extraction of contaminating pigments was obtained at pH 4.5. Pigments and other contaminants are removed by thin layer chromatography using a solvent system chloroform-isopropyl alcohol-ethanol-formic acid (45:5:0.5:0.3). The isolated PGs were determined by GC-ECD after appropriate derivatization. The overall recovery of PGs using this procedure is 60%.

Metabolism of trans fatty acids with emphasis on the effects of trans, trans-octadecadienoate on lipid composition, essential fatty acid, and prostaglandins: an overview

Information concerning the metabolism of trans isomers of dietary unsaturated fatty acids is presented. Dietary trans-octadecenoic and trans,trans-octadecadienoic acids are apparently absorbed, activated, oxidized, and acylated into ester lipids much like saturated fatty acids although differences have been observed with regard to their metabolism by different organs. Because of the important role of linoleic acid as the principal precursor of cyclic endoperoxides, prostaglandins and leukotrienes, the potential deleterious effects of trans isomers of this acid are discussed. High levels of dietary trans,trans lineoleate can impair delta 6 desaturase activity and decrease prostaglandin production in rats on experimental diets.

A new prostaglandin, C22-PGF4 alpha, synthesized from docosahexaenoic acid (C22:6n3) by trout gill

The concentrations of prostaglandins PGE3 and PGF3 alpha were 214 and 1500 ng/g wet trout gill tissue, respectively. A new prostaglandin, tentatively identified by gas chromatography/mass spectrometry as C22-PGF4 alpha (590 ng/g wet tissue) was discovered. This was synthesized from docosahexaenoic acid.

Prostaglandin E1 and E2 in bovine semen: quantification by gas chromatography

Prostaglandins PGE1 and PGE2 extracted from bovine semen, purified via silicic column chromatography were quantified by gas chromatography as their methoxime methyl ester trimethylsilyl ether derivatives. The PGE2 and PGE2 concentrations of 19 bovine semen samples ranged from 395 +/- 225 and 487 +/- 407 ng/ml, respectively. A constant 1:1 ratio between PGE1 and PGE2 was observed. There was not relationship between PGE and sperm motility, but high sperm counts were generally associated with decreased PGE levels. The direct precursors of PGE1 and PGE2, i.e. 20:3n6 and 20:4n6, occurred in low concentrations compared to other related unsaturated fatty acids, i.e. 18:2n6 and 22:5n6 of the n-6 family.