Effect of some antineoplastics on metabolic heme pathway

1. The porphyrinogenic ability of several antineoplastics used in the therapy of the different cancers was evaluated. The action of cyclophosphamide, busulfan and 5-fluorouracil on the amount and nature of the accumulated hepatic porphyrins and on the activity of delta-aminolaevulinate synthase (ALA-S), were estimated at different doses and times of drug treatment in 17-day-old chick embryos. 2. It was observed that cyclophosphamide produces a significant increase in the accumulation of hepatic porphyrins at different doses as well as in the activity of the ALA-S, at all the incubation times. Cyclophosphamide alters the pattern of porphyrins accumulated in the liver, where a coproporphyrin: protoporphyrin ratio higher than in the controls can be observed. 3. Busulfan increased the hepatic porphyrins accumulated in the liver but to a lesser degree than cyclophosphamide. 4. 5-Fluorouracil did not modify the hepatic porphyrin content when it was administered at doses up to 40 mg/embryo. 5. When the embryos were injected with busulfan or 5-fluorouracil no significant differences were observed in the activity of ALA-S up to 11 hr of incubation. 6. These results indicate that cyclophosphamide has a remarkable porphyrinogenic capacity in chick embryo while busulfan, notwithstanding the fact that it alters the haem pathway, it does so to a degree that does not impair the regulation of ALA-S activity. Fluorouracil seems to be non porphyrinogenic in this system, up to 40 mg/embryo.     

A comparison of two plating techniques to estimate plasmid stability of a prolonged chemostat culture

Summary A comparison of two plating techniques to estimate the segregational stability ofEscherichia coli RR1 harboring plasmid pBR322 in a chemostat was studied. No significant differences were observed between the spread and replica plating techniques in the beginning of the experiments. However, a noticeable discrepancy between these two methods appeared after approximately 100 hours. This inconsistency can be shown to be statistically significant.     

Chronic Pseudomonas aeruginosa endobronchitis in rhesus monkeys: II. A histopathologic analysis

We have recently established a rhesus monkey model of chronic Pseudomonas aeruginosa (PA) endobronchitis by bronchoscopic instillation of PA-embedded agar beads. All experimental animals developed chronic neutrophilic endobronchitis similar to chronic PA endobronchitis in cystic fibrosis (CF). Histopathologic studies further confirmed similarities to chronic PA endobronchitis in CF, including marked peribronchial inflammation, epithelial damage, presence of degraded cilia and ciliary abnormalities, appearance of PA bacterial clusters, mucosal hyperplasia, goblet cell hypertrophy/hypersecretion, airway obstruction, alveolar abnormalities, bronchiectasis, and fibrosis.     

Purification and structure of caltrin-like proteins from seminal vesicle of the guinea pig

Two different small proteins that cross-react with the antiserum against bovine caltrin (calcium transport inhibitor) have been purified from the seminal vesicle contents of the guinea pig. The primary structure and some molecular characteristics of the pure proteins are reported. The two proteins interact with concanavalin A indicating the presence of carbohydrates in their molecules. Chemical deglycosylation with trifluoromethanesulfonic acid, after reduction and carboxymethylation, results in complete loss of affinity for the lectin. Removal of sugar components from the structure destroys the ability of caltrin-like proteins to react with antibodies to bovine caltrin. The protein moving faster on polyacrylamide gel electrophoresis is designated guinea pig caltrin I, the other is II. They contain 45 and 55 amino acids, and the molecular weights of the peptide portions are 5082 and 6255, respectively. Although they have entirely different amino acid sequences, they share some common features: recognition by rabbit antibodies to bovine caltrin, the predominance of basic residues and the presence of 3 cysteine residues in fraction I and 8 in fraction II. The proteins have pI values of 9.5 and 10.2, respectively, which are consistent with the amino acid composition. The two pure fractions are approximately equally effective, on a weight basis, as inhibitors of 45Ca2+ uptake by guinea pig spermatozoa. The data presented reinforce the hypothesis that caltrin-like proteins are responsible for the previously reported (Coronel, C.E., San Agustin, J., and Lardy, H.A. (1988) Biol. Reprod. 38, 713-722), calcium-transport inhibitor activity detected in reproductive tract fluid from adult male guinea pigs.     

Trisomy 13 in a 4-year-old child

Summary The karyotype 47,XY,13+ was observed in a mentally retarded four-year-old child, with numerous abnormalities and the typical dermatoglyphics of a trisomy 13. Banding analysis showed a complete extra chromosome 13.