Effect of Ferricyanide, Ferrocyanide and KCN on Growth and Flowering in the Short-Day Plant Lemna paucicostata 6746

Flowering in the short-day plant Lemna paucicostata 6746 canbe induced under continuous light by the addition of ferricyanie,ferrocyanide or KCN to M-sucrose medium. Each substance is nearly10 times more effective when the flasks are covered by glassbeakers than when cotton plugs are used. By contrast, when floweringis induced under continuous light by copper or by short-daytreatment, neither flowering nor growth are affected by whetherglass beakers or cotton plugs are used. Ferricyanide, ferrocyanideand KCN are also able to induce long-day flowering when theplants are grown on Msucrose medium in small beakers that areplaced in a covered storage dish that also contains a solutionof one of these compounds. Addition of a KOH trap to the storagedish completely blocks the flowering induced by these compounds.If [¹⁴C]ferrocyanide is added to the storage dish both the M-sucrosemedium and the plants contain significant amounts of radioactivity,the amount of radioactivity being proportional to the floweringresponse. These results indicate that ferricyanide, ferrocyanideand KCN break down to release HCN and that it is the HCN whichis responsible for inducing flowering in L. paucicostata 6746under continuous light. ¹Present address: Department of Biology, Osaka Kyoiku University,Ikeda, Osaka 563, Japan. ²Present address: Institute of Horticulture, The Volcani Center,P. O. B. 6, Bet-Dagan, Israel. (Received January 17, 1983; Accepted March 24, 1983)     

Larval development of Diploptera punctata reared alone and in groups

Larvae of the cockroach Diploptera punctata were reared in isolation, in pairs, or in groups of 8–10. Duration of larval development, age at each ecdysis, weights at birth and ecdyses, and adult head-capsule width were measured. Duration of larval development was longer and adult size was larger in isolated animals than in animals reared in pairs and groups. The effect of isolation on development was more pronounced in males. All females had 4 larval instars, whereas males had 3 or 4 instars. The proportion of males with 4 larval instars was higher among animals reared in isolation. There was no difference in the duration of larval development or adult size between pair- and group-reared animals. The sex of animals in the group did not affect adult size or the duration of larval development. Males which underwent 3 or 4 larval instars had different schedules of moulting. Rates of growth of males of both instar types reared in isolation and pairs were similar. Greater adult weight of isolated animals and 4-instar-type males was a result of their longer duration of larval development. Both a higher rate of growth and longer duration of larval development contribute to the larger adult size of females than males.     

Comparison of Two Therapeutic Regimens Using the Same Topical Corticoid for Stable Psoriasis

In a masked, randomized, concurrently controlled clinical trial we compared the therapeutic response of two regimens in which the same topical corticoid was used to treat 52 men who had stable psoriasis. One regimen, called reduced dose, consisted of once-a-day application of a representative potent fluorinated topical steroid ointment, fluocinonide (Lidex), combined with three-times-a-day application of its vehicle. The other regimen, called traditional dose, consisted of four-times-a-day topical application of the same steroid. Patients were assigned to one of the two regimens and observed for six weeks. Confidence intervals for the difference in true mean response under these two regimens provide good evidence that for these patients the traditional dose was not clinically superior to the reduced dose.     

Implication of Triticum searsii as the B-genome donor to wheat using DNA hybridizations

In vitro DNA:DNA hybridizations and hydroxyapatite thermal chromatography were employed to help identify the species ancestral to the B genome of the polyploid wheats. We hybridized 3H-Triticum aestivum DNA to the unlabeled DNAs of T. urartu, T. speltoides, T. sharonensis, T. bicorne, T. longissimum, and T. searsii, 3H-Labeled DNA of T. urartu was hybridized with the DNA of a synthetic tetraploid. AADD. The heteroduplex thermal stabilities indicated that T. searsii was most closely related to T. aestivum (ABD) and that the genome of T. urartu was more closely related to the A genome than the B genome. The degree of reassociation which may have occurred between the six diploid species and the D genome of T. aestivum was evaluated by hybridizing 3H-T. tauschii DNA with the DNAs of the diploids. The results indicated that T. urartu had the least sequence homology to T. tauschii, the D-genome donor lending additional support to the conclusion that T. urartu is related to the A genome. Thus, it is highly probable that T. searsii is the B-genome donor to the polyploid wheats or a major chromosome donor if the B genome is, in fact, polyphyletic in origin.     

Termination of early gestation with vaginal prostaglandin F2α tablets

The abortifacient activity of prostaglandin F_2α was investigated by placing one or two 50 mg tablets of prostaglandin F_2α in THAM salt into the vagina of nine women less than 4 weeks pregnant at intervals of 2 to 4 hours for a 24 hour period. Serum levels of HCG, estradiol (E₂), progesterone and 17α-hydroxyprogesterone were measured by radioimmunoassay prior to starting therapy and at frequent intervals thereafter for 48 hours. All but two patients had significant side-effects, mainly diarrhea and vomiting, indicating that systemic absorption took place. Although bleeding was induced in 8 of 9 women, only 3 had complete abortions. A D&C was performed on all patients 48 hours after starting therapy. A significant fall in HCG levels was noted only in the patients who aborted. Only 3 of the 9 women had significant changes in steroid levels. A fall in progesterone and 17α-hydroxyprogesterone occurred in the 3 women who aborted and took place following the fall in HCG. Estradiol levels remained in the same range in all subjects. These findings indicate that prostaglandin F_2α when administered in this vehicle and this dosage is relatively ineffective as an abortifacient. When effective, its action would appear to be due to contractions of uterine muscle and not secondarily to luteolysis.     

Arylamidase of Cephalosporium acremonium and Its Specificity for Cephalosporin C

Three aggregational forms of arylamidase are produced by Cephalosporium acremonium. The exocellular enzyme, with an approximate molecular weight of 60,000, was purified 300-fold by diethylaminoethyl cellulose chromatography, gel filtration, and gel electrophoresis. With l-leucyl-beta-naphthylamide as the substrate, the K(m) is 4.2 x 10(-4)m; the optimum pH, 7.7; and the temperature optimum, 35 C. The enzymatic hydrolysis of l-leucyl-beta-naphthylamide is inhibited by a number of cephalosporins, whereas a variety of penicillins show no effect. Alternatively, the enzyme specifically catalyzes the beta-lactam hydrolysis of a number of cephalosporins; a number of penicillins are resistant. The K(m) for cephalosporin C is 9.09 x 10(-4)m.     

Comparison by Gas-Liquid Chromatography of the Fatty Acids of Mycobacterium avium and Some Other Nonphotochromogenic Mycobacteria

Fifty-eight strains of nonphotochromogenic mycobacteria representing nine different serotypes were studied, including 38 strains of Mycobacterium avium and 20 strains of Battey bacilli. The lipids were extracted from whole cells, saponified with potassium hydroxide, and esterified with diazomethane. The fatty-acid profiles determined by gas-liquid chromatography included saturated fatty acids ranging from C(8) to C(24), plus some unsaturated analogues and a branched-chain acid. No consistent differences in the fatty-acid profiles were observed between strains of M. avium and Battey bacilli. Quantitative differences in the means (significant at P < 0.01) were observed in the relative amounts of 14:0, 16:1, 18:0, 18:1, and a branched-chain acid among strains of the same serotype. We were unable to differentiate the fatty-acid profiles of recently isolated strains or those maintained in culture for more than 2 years.