Quantification of in-vitro post-antibiotic effect based on the mean recovery-time. II: A comparison of colony counting versus photometric methods for the determination of bacterial growth

In the preceding paper, a method for the quantification of the post-antibiotic effect (PAE) has been developed based upon the mean recovery-time of an antibiotic-treated bacterial population, showing that the mean recovery-time is determined by the area above a growth curve of the bacterial population. Such an area determination of PAE implies that this method is less likely to be influenced by the early portion of a growth curve and therefore less dependent on the ability of a technique to detect a minimum bacterial density (sensitivity limit). In this study, this implication is further demonstrated in theory and through experimentation. As a result, an approach to estimation of contribution of the early portion of a growth curve to the quantitation of PAE based on the mean recovery-time is derived. The PAE of ciprofloxacin on Escherichia coli ATCC 25922 was determined under different test conditions using colony count and optical density measurements for determining bacterial growth. Differences in durations of the PAE quantitated by the mean recovery-time from the colony count measured and optical density measured growth curves were not statistically significant (P greater than 0.05).

[Karyotype analysis on bulbus Lilii]

A karyotype analysis has been made of the chromosome of five original species of Lilium. Lanceleaf Lily is the allotriploid.

[Herbalogical studies on bulbus Lilii]

A textual research has been carried out herbalogically on Bulbus Lilii, along with a pharmacological study and resources investigation. Lanceleaf Lily is regarded as the first choice of the drug.

[Application of cluster analysis of the study of commodity bulbus Lilii (I)]

Cluster analysis has been applied to the classification of various commodities of Bulbus Lilii in order to sort out the main one. The stomatic index of the commodity has been determined.

A simple method for generation of antibodies with specificity for 1,25-dihydroxyergocalciferol and 1,25-dihydroxycholecalciferol

A simple method for production of antisera with high affinity and selectivity for 1 alpha, 25-dihydroxyergocalciferol and 1 alpha, 25-dihydroxychole-calciferol is described. 1 alpha-Hydroxy-25,26,27-trisnorcholecalciferol-24-oic acid was coupled directly to bovine serum albumin. Rabbits immunized with this conjugate rapidly produced antibodies that bound 3H-1 alpha,-25-dihydroxycholecalciferol with high affinity and demonstrated nearly equal reactivity with 1 alpha, 25-dihydroxyergocalciferol and poor reactivity with 25-hydroxycholecalciferol; 24,25-dihydroxycholecalciferol; 25,26-dihydroxycholecalciferol; and 1 beta,25-dihydroxycholecalciferol. The use of one of these antisera has led to the development of a specific assay for 1 alpha,25-dihydroxyergocalciferol and 1 alpha,25-dihydroxycholecalciferol in human serum.