Formation in the presence of C3 nephritic factor (C3NeF) of an alternative pathway C3 convertase containing uncleaved B

C3 nephritic factor (C3NeF) interacts with native C3 and B in the absence of D to generate a C3 convertase containing an uncleaved form of B. Dose response studies with C3NeF and B, respectively, revealed incremental C3 inactivation without loss of B. These findings are in agreement with the previous isolation from such reaction mixtures of a 10S complex containing haemolytically inactive C3 and active B and manifesting C3 convertase activity. Functional contamination of C3 with C3b was negated by demonstrating that pretreatment of C3 with C3bINA had no effect on its subsequent interaction with B and C3NeF to generate C3 convertase activity, while pretreatment of C3b eliminated its effective interaction with B and C3NeF. Relatively higher concentrations of C3bINA present during interaction of C3, B and C3NeF suppressed C3 inactivation, indicating its dependence on amplification by utilization of the initial C3b generated. Trace quantities of D were not found by functional analyses of C3, B and C3NeF and pretreatment of these proteins with a concentration of DFP sufficient to suppress D activity had no effect on their effective interaction. The introduction of D to mixtures of C3NeF, B, and C3 resulted in B clevage and more efficient expression of C3 convertase function as defined by a reduced requirement for C3NeF.     

Comparison of human and hamster mitochondrial transfer RNA. Physical properties and methylation status

In a comparative study, the effective of intraventricularly or intraperitoneally injected p-chloroamphetamine (p-CA) and some chloroindoles on cerebral levels of serotonin was evaluated. 5-Chloroindole depressed 5-HT levels in the brainstem and telencephalon for three days, 6-chloro-2-methylindole (6-CMI) only during the first day. 5-Chloroindazole had no effect at all. p-CA was more toxic to guinea pigs than to rats. p-CA and 5-chloro-2-methylindole (5-CMI) had no effect on cerebral 5-HT in chicks. Apparently, none of these compounds represented or was converted to a metabolite possibly responsible for the neurotoxic effects of p-CA.     

Theophylline and dyphylline levels in serum by liquid chromatography

The widespread use of theophylline and dyphylline as bronchodilators in the treatment of acute and chronic obstructive airway disease, and recognition of the need to control the therapeutic drug level has created a demand for fast accurate measurement techniques. Measurement of theophylline levels by ultraviolet spectrophotometric techniques is hindered by interferences from barbiturates and caffeine, and thermal lability of the drug necessitates derivatization if gas chromatography is to be used. Because of these factors, a liquid chromatographic method has been developed which allows separation of the underviatized drug from interfering compounds, and quantitation of the theophylline in a single operation. In addition, the drug-containing fraction can be readily collected and subjected to mass spectral examination if there is any question as to its identify. The latter feature has particular significance in medico-legal cases.     

Säulenchromatographische Abtrennung von Phospholipiden aus Gesamtlipidextrakten

Column Chromatographic Separation of Phospholipids from Total Lipid Extracts The separation of phospholipids out of total lipid extracts is described by using a column chromatographic method. Up to 800 mg total lipids in a mixture of chloroform and methanol (19 : 1, v/v) may be applied to dry-column-chromatography using 5 g silica gel as a matrix. Neutral lipids and free fatty acids are elutet by propanol-2. Following extraction of phospholipids is achieved by methanol, containing 0.5 ml/100 ml ammonia solution (25%). In the course of the preparation no lyso-phospholipids are formed and the composition of the phospholipidfraction is not altered. The recovery of applied phospholipids amounts 98-99.5%.