Concomitant determination of thiamin and its phosphate esters in human blood and serum by high-performance liquid chromatography

A high-performance liquid chromatographic method for the simultaneous determination of thiamin and thiamin phosphate esters in human blood or serum has been developed. The eluent consists of acetonitrile and phosphate buffer, in the ratios 90:10 (v/v) for the elution of thiamine and 60:40 (v/v) for the phosphate esters. The four compounds are eluted within 15 min. The detection limit is 13-16 fmol. Between-assay variation is 5-11%. Samples of whole blood and serum from 30 healthy adults were analysed. The following reference values were obtained for 15 females 15 males (nM, mean +/- S.D.). In serum: thiamin, 10.9 +/- 2.9/16.9 +/- 3.3; thiamin monophosphate, 8.3 +/- 1.5/3.7 +/- 1.5. In whole blood: thiamin, 29.6 +/- 10.0/33.4 +/- 10.4; thiamin monophosphate, 9.7 +/- 2.3/10.9 +/- 5.1; thiamin diphosphate, 121 +/- 29.6/165 +/- 40.4.

Characterization of the morphological properties of welding fume particles by transmission electron microscopy and digital image analysis

The morphological characteristics of welding fume particles have been determined using transmission electron microscopy (TEM) and automatic image analysis (AIA). Two personal samples and one background sample were collected using a new, easy to handle sampling method, during tungsten inert gas (TIG) and manual metal arc (MMA) welding on Inconel in the same shop. The collection method gave samples which were suitable for TEM and AIA. Electron micrographs were taken in a transmission electron microscope and further analyzed using an image analysis unit. Aggregates composed of many individual particles were analyzed both for the parameters of the aggregate and for the parameters of the individual particles by using an algorithm based on a grain boundary reconstruction technique. The morphological parameters allowed the welding fume's particulate matter to be divided into three types - here called small, medium, and large - with a somewhat unclear distinction between medium and large. Medium and large particles occur either as individual particles or as clusters of approximately spherical particles with average diameters of 0.07 and 0.15 microm, respectively. Small particles occur almost exclusively as long chains or lace-like structures of aggregates of particles, often in the range of 5-10 microm. The aggregates have an average projected area of 2.6 x 10-3 microm2 and are composed of several hundred individual particles.

Obstetric behavior and ultrasonic uterine characteristics of oligomenorrheic women

Two groups of age-, parity-, and pregnancy-matched women, viz. 78 with oligomenorrhea (A) and 78 with normal menstrual intervals (B), plus all women with regular menstruation but in whom severe Müllerian malformations had been diagnosed during the same period (C) were followed in a prospective study to detect complications, sonographic changes, and the serum oxytocinase concentration during pregnancy and labor. Among the matched groups A and B, ultrasonic scanning revealed uterine changes in 45% and 9%, respectively (p less than 0.0005) during the 2nd trimester. Among the oligomenorrheic women who had HSG, fairly mild Müllerian malformations were found in 40%. The sonographic method in these mild and moderate anomalies had its limitations, and the findings were interpreted in several cases as fibroma or contractions. Complications occurred in 51% of the group A women who carried their pregnancies to term versus 20% in group B (p less than 0.0005). Among the primiparae the complication rates were 47% and 22%, respectively (p less than 0.025). Bleeding in early pregnancy (25%), an unstable fetal lie (28%), malpresentations (14%), and premature contractions or delivery (11%) were more common in group A (p less than 0.05-0.01). On stratification of the oligomenorrheic group without or with Müllerian anomalies (A1 and A2) the overall complication rates were 55% and 73%, respectively, and 86% in group C. Mutually, these differences are not statistically different, but all differ significantly from the control group (B) (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Tubocutaneous fistula. Case report

A 40-year-old woman with Crohn's disease had a cutaneous fistula discharging only during menstruation. Surgical exploration showed a tubocutaneous fistula. Such fistula is extremely rare without prior surgery of the reproductive organs. Discharge during menstruation was the salient feature in most reported tubocutaneous fistulas. Resection of the fistula and salpingectomy is the treatment of choice.

Studies on curcumin and curcuminoids. IX: Investigation of the photobiological activity of curcumin using bacterial indicator systems

The dye curcumin is a natural, nontoxic food constituent. On irradiation with visible light, curcumin proves to be phototoxic for Salmonella typhimurium and Escherichia coli, even at very low concentrations. The observed phototoxicity makes curcumin a potential photosensitizing drug which might find application in the phototherapy of, for example, psoriasis, cancer, and bacterial and viral diseases.

Methotrexate in infusion solutions--a stability test for the hospital pharmacy

The stability of methotrexate solutions, subject to a freeze-thaw procedure, has been investigated. According to our results these solutions can be produced in batches in the hospital pharmacy and thawed to room temperature immediately before use without any degradation of methotrexate within the time limits given.

Studies on curcumin and curcuminoids. VIII. Photochemical stability of curcumin

The photodecomposition of curcumin when exposed to UV/visible radiation is studied. The main degradation products are identified. The reaction mechanisms are investigated and the order of the over-all degradation reactions and the half-lives of curcumin in different solvents and in the solid state are determined.

Studies on curcumin and curcuminoids. VI. Kinetics of curcumin degradation in aqueous solution

The kinetics of the pH-dependent degradation of curcumin has been investigated. A plot of the rate constant against pH indicates the pKa values of the acid protons. The graph also indicates the complexity of the curcumin degradation.

Rapid isothermal gas--liquid chromatographic determination of tricyclic antidepressants in serum with use of a nitrogen-selective detector

A rapid and simple gas--liquid chromatographic method suitable for routine use is described for quantitation of tricyclic antidepressants. The method can be used for quantitation of amitriptyline, nortriptyline, imipramine, desmethylimipramine, doxepin, desmethyldoxepin, clomipramine, desmethylclomipramine, trimipramine, desmethyltrimipramine and dibenzepine. The method involves one extraction with hexane--isopropyl alcohol, no derivative formation of the metabolites and chromatography using an OV-25 liquid phase which permits isothermal quantitation of the different drugs within 5--10 min. Standard curves for the different tricyclic antidepressants were linear over the concentration range tested (10--1500 micrograms/l) and the maximum coefficient of variation was 7.7%.

Changes in blood volume and extravascular water content in isolated perfused rat lungs during ventilation hypoxia

Isolated rat lungs were perfused with homologous blood at constant volume inflow. The effect of ventilation hypoxia on pulmonary vascular resistance, preparation weight and reservoir volume (vascular capacitance) were studied. In some experiments also wet/dry weight ratio of the preparation was estimated (extravascular water content). There was no difference in this last parameter between hypoxic and normoxic lungs, thus alveolar hypoxia had no effect on tissue water content as previously described in intact rats. With forward perfusion small and transient changes in either direction were seen in preparation weight and reservoir volume, even though inflow pressure exceeded 5 kPa during alveolar hypoxia. With backward perfusion marked weight increases were seen, and if inflow pressure in this situation was above 3.5 kPa, the weight change was irreversible, thus indicating outward fluid filtration. It is concluded that the vessels responding to alveolar hypoxia are located on the arterial side of the pulmonary vasculature.

Blood volume and extravascular water content in the rat lung during acute alveolar hypoxia

Values for pulmonary blood volume and extravascular lung water (estimated as wet weight of lung tissue) were arrived at in intact, anesthetized rats by labelling of blood constituents with isotopes and rapidly freezing the whole animals in liquid nitrogen. On ventilating the animals with 10% O2 in N2/N2O, a reduction in lung blood content could be demonstrated. The degree of reduction depended on the type of anesthesia and ventilation used. In some animals the volume reduction was so marked that both arterial, venous and capillary blood compartments have most probably been involved. The water content of the lung tissue was also rapidly and markedly reduced during hypoxia. Increased plasma osmolarity in mixed venous blood could partly be responsible for this tissue water reduction.

An all-purpose injection system for gas chromatographic analyses of biological samples

A versatile injection system for the direct introduction of samples into the gas chromatograph (GC) is described. Several years of experience in biological and pharmaceutical chemistry have led to the construction and final modification of this device. No modification of the injection port of the GC is necessary.

Effects of catecholamine-infusions and hypoxia on pulmonary blood volume and extravascular lung water content in cats

The effects of catecholamine-infusions and of hypoxia on lung blood volume and on extravascular lung water content have been studied in anesthetized cats with opened chests. To this end a biopsy technique, with isotope labelling of blood and with successive removal of the smaller lung lobes, was employed. Mean pulmonary arterial pressure increased by 30-75% upon infusing catecholamines or upon inducing general hypoxia, the latter stimulus being the more powerful one. Pulmonary blood volume did not increase during these procedures, where an active constriction of pulmonary vessels thus apparently took place. The extravascular lung water content was found to be reduced in animals infused with noradrenaline or ventilated by hypoxic air, whereas a small increase was observed in the animals receiving adrenaline. This difference might reflect domination of precapillary vasoconstriction in the former groups, whereas postcapillary vasoconstriction could be more pronounced with adrenaline.