A new species of Croton (Euphorbiaceae) widespread in Mexico

Croton rzedowskii is described, the type being from San Luis Potosí. The species ranges from San Luis Potosi westward to Zacatecas, thence southeastward to Oaxaca.     

Serological Comparison of Spherules and Arthrospores of Coccidioides immitis

Spherule and arthrospore cellular preparations were sonic-treated and separated into their respective supernatant and sediment components. Complement-fixation tests with antispherule and antiarthrospore pooled rabbit sera revealed that the soluble antigens exhibited more serological activity than the sediment preparations. After autoclaving, an arthrospore cellular antigen exhibited increased activity with either antisera, whereas autoclaved spherules exhibited increased activity only with antispherule serum. Complement-fixation tests with coccicioidin and spherule culture supernatant preparations revealed quantitative or qualitative differences in antigenic determinants between these two morphological phases of Coccidioides immitis.     

Comparison of effects of oxytocin and prostaglandin F2-alpha on circular and longitudinal myometrium from the pregnant rat

Previous studies showed that circular (CM) and longitudinal myometrium (LM) have different physiological and pharmacological characteristics. To determine if such differences also exist with respect to the actions of oxytocin and prostaglandin F2-alpha (PGF2 alpha), we compared the effects of these agents on the spontaneous contractions of CM and LM from rats on Days 15, 17, and 21 (term) of pregnancy. Both agents stimulated CM and LM on all gestation days, but the responses differed as follows: 1) the CM response to oxytocin was all-or-nothing on Days 15 and 17, to PGF2 alpha on Day 15, and was graded to both agents only at term; 2) the LM response to both agents was always graded; 3) the maximum response to oxytocin was always less in CM than in LM, and to PGF2 alpha was less in CM except at term, when it was greater than in LM; 4) the EC50 (effective concentration that produced 50% of the maximum response) for PGF2 alpha in CM was greater than in LM, indicating a lesser sensitivity of CM for this agent. Therefore, the heterogeneity between CM and LM extends to the effects of oxytocin and PGF2 alpha, further emphasizing the importance of distinguishing between the two muscle layers in studies of uterine activity.     

Identification of Campylobacter coli isolates from animals and humans by bacterial restriction endonuclease DNA analysis.

Ninety-nine Campylobacter coli isolates were examined by bacterial restriction endonuclease DNA analysis (BRENDA) with HindIII. Isolates from poultry from the same environment had identical patterns, patterns of isolates carried by suckling piglets were generally the same as those of isolates recovered from their dams, and one human patient yielded the same BRENDA type when sampled 6 weeks later. The 14 human isolates examined produced 11 distinct BRENDA types. Forty-three C. coli isolates from pigs were represented by 20 BRENDA types. Ten C. coli isolates from the feces of gulls yielded five different BRENDA types. Thirty-two C. coli isolates from live chickens and processed chicken yielded five different BRENDA types. Three human isolates had identical DNA patterns; two were from brothers living in the same house, and the third was from a human with no apparent relationship to the brothers. Another human isolate was identical to a poultry isolate. None of the pig strains had DNA patterns resembling those of human strains, nor were the DNA patterns like those of any strains recovered from poultry or gulls. Four C. coli isolates were subcultured onto agar 23 times over a period of 45 days, and their BRENDA patterns were preserved. BRENDA shows great promise for use in epidemiological studies of C. coli.