Crop wild relative populations of Beta vulgaris allow direct mapping of agronomically important genes.

Rapid identification of agronomically important genes is of pivotal interest for crop breeding. One source of such genes are crop wild relative (CWR) populations. Here we used a CWR population of <200 wild beets (B. vulgaris ssp. maritima), sampled in their natural habitat, to identify the sugar beet (Beta vulgaris ssp. vulgaris) resistance gene Rz2 with a modified version of mapping-by-sequencing (MBS). For that, we generated a draft genome sequence of the wild beet. Our results show the importance of preserving CWR in situ and demonstrate the great potential of CWR for rapid discovery of causal genes relevant for crop improvement. The candidate gene for Rz2 was identified by MBS and subsequently corroborated via RNA interference (RNAi). Rz2 encodes a CC-NB-LRR protein. Access to the DNA sequence of Rz2 opens the path to improvement of resistance towards rhizomania not only by marker-assisted breeding but also by genome editing.

An update of two randomized trials in previously untreated multiple myeloma comparing melphalan and prednisone versus three- and five-drug combinations: an Argentine Group for the Treatment of Acute Leukemia Study.

An update of two consecutive randomized studies in previously untreated multiple myeloma was performed. The first study (10-M-73) began in 1973; 150 patients were treated with melphalan and prednisone (MP) or semustine, cyclophosphamide, and prednisone (MeCP). In a second randomized study (3-M-77), begun in 1977, 260 patients were treated with MP or melphalan, prednisone, cyclophosphamide, semustine, and vincristine (MPCCV). A total of 27 of the 67 patients (40%) treated with MP and 33 of the 83 patients (40%) treated with MeCP showed a good response in protocol 10-M-73; 48 of 145 patients (33%) treated with MP and 51 of the 115 patients (44%) treated with MPCCV in protocol 3-M-77 obtained a good response (P is not significant). Median survival in protocol 10-M-73 was 30 months for MeCP and 38 months for MP. At 84 months, 19% and 9% remain alive, respectively. Median survival for protocol 3-M-77 was 44 months for those treated with MPCCV and 42 months for MP. At 60 months, 9% and 11% remain alive; this difference was not significant. Also, there was no survival difference for favorable or unfavorable prognostic groups among the four treatment arms of both protocols. It can be concluded, with a long-term follow-up of both protocols, that the combination of MP is as effective as the three- and five-drugs combinations, and in view of its simplicity and cost-saving advantages, it should be favored for initial therapy of multiple myeloma patients.

A randomized trial of melphalan and prednisone versus melphalan, prednisone, cyclophosphamide, MeCCNU, and vincristine in untreated multiple myeloma.

In a randomized study with 234 previously untreated patients with multiple myeloma, 129 were treated with melphalan (8 mg/m2 perorally for four days) and prednisone (40 mg/m2 perorally for seven days, both every four weeks) and 105 with melphalan and prednisone at the same doses plus cyclophosphamide (600 mg/m2 intravenously every four weeks), MeCCNU (100 mg/m2 PO every eight weeks), and vincristine (MPCCV, 0.6 mg/m2 IV every four weeks). A total of 49 (38%) of the 129 patients treated with melphalan and prednisone (MP) and 48 (46%) of the 105 patients treated with MPCCV showed good response (GR) (P not significant); the overall response rates were 58% and 70%, respectively. Thirty-seven percent of the MP group and 39% of the MPCCV group remain alive at 48 months from first treatment (P not significant). The estimated 48-month survival from first treatment, according to different prognostic factors at diagnosis, in both groups was as follows: stage 1,56%; stage II, 46%, and stage III, 23% (I and II v III P less than .001). Survival at 48 months according to response was GR, 68%; partial response (PR), 33%; and null, 16% (GR v null, P less than .0005; GR v PR, P less than .0005). Survival according to renal function was 43% for a creatinine level less than 2 mg/100 mL and 27% for a creatine level greater than or equal to 2 mg/100 mL (P less than .0005). No significant difference has been found between the two treatment schedules in terms of response rate and survival time, in any stage of disease.

Deepoxidation of 16-membered epoxyenone macrolide antibiotics. I. Microbial deepoxidation and subsequent isomerization of deltamycins A1, A2, A3, A4 (carbomycin A) and X.

Carbomycin A (deltamycin A4) was deepoxidized to carbomycin A P1 by Streptomyces halstedii subsp. deltae (a deltamycins producer), favorably under anaerobic conditions. Carbomycin A P1 was spontaneously converted to geometric isomers designated carbomycins A P2 and A P3. This type of deepoxidation and subsequent isomerization was not limited to carbomycin A, but generally occurrable in other 16-membered epoxyenone macrolide compounds. Many bacteria and actinomycetes were also found to have an ability to deepoxidize deltamycins reductively. The chemical structures of carbomycins A P1, A P2 and A P3 were elucidated as shown in Fig. 3.

PS-5, a new beta-lactam antibiotic. III. Synergistic effects and inhibitory activity against a beta-lactamase.

PS-5 was shown to have synergistic activity in combination with other beta-lactam antibiotics and it markedly decreased the minimum inhibitory concentration values of ampicillin or cephaloridine with a beta-lactamase-producing Proteus vulgaris strain on agar plates. The synergistic activities were also shown in bactericidal activity in liquid medium. PS-5 was shown to be inhibitory against an extracted beta-lactamase of P. volgaris.

Deepoxidation of 16-membered epoxyenone macrolide antibiotics. III. In vitro and in vivo evaluation of deepoxidation products of carbomycin A, deltamycin A1, 4"-phenylacetyldeltamycin, angolamycin and rosamicin.

Deepoxidation products P1, P2 and P3 of carbomycin A, deltamycin A1 and 4"-phenylacetyldeltamycin showed high in vitro antibacterial and antimycoplasmal activities which were comparable to those of the respective parent compounds. By contrast, the in vitro antimicrobial potencies of angolamycin P1 and rosamicin P1 were about ten-fold lower than those of the parent macrolides. In mice, the increase in the plasma levels of the epoxyenone macrolides due to deepoxidation was highly significant with the P1, P2 and P3 derivatives of carbomycin A and 4"-phenylacetyldeltamycin, whereas angolamycin P1 gave a moderately-improved plasma level compared with angolamycin.

Deepoxidation of 16-membered epoxyenone macrolide antibiotics. II. Chemical deepoxidation by dissolving metal reduction.

16-Membered epoxyenone macrolide antibiotics were reductively deepoxidized with dissolving metals such as zinc. Angolamycin and rosamicin which have a methyl substituent at C-12 in the epoxyenone structure were deepoxidized, but not isomerized further to the geometric isomers P2 and P3.

Deltamycins, new macrolide antibiotics. II. Isolation and physicochemical properties.

The new macrolide antibiotics were isolated by silica gel chromatography. They showed a UV absorption maximum at 240 nm. Deltamycins A1, A2 and A3 were demonstrated to be new macrolide antibiotics on the basis of their physicochemical properties whereas deltamycin A4 was identified as carbomycin A.

Controlled biosynthesis of neoviridogriseins, new homologues of viridogrisein. I. Taxonomy and fermentation.

Neoviridogriseins, new homologues of viridogrisein, were produced with viridogrisein and griseoviridin by Streptomyces sp. P8648 which was identified as a strain of Streptomyces griseoviridus.

PS-6 and PS-7, new beta-lactam antibiotics. In vitro and in vivo evaluation.

Biological properties of two new beta-lactam antibiotics, PS-6 and PS-7, containing the carbapenem nucleus were studied. The in vitro activities of PS-6 and PS-7 were tested against clinical isolates of Gram-positive and Gram-negative bacteria in comparison with those of cefazolin, ampicillin and PS-5. In general, the antibacterial spectra of PS-6 and PS-7 were similar to that of PS-5. PS-7 was slightly less active than PS-5 and ABPC against Staphylococcus aureus. Clinical isolates of Gram-negative bacteria were found to be 2- to 8-fold more resistant to PS-6 than to PS-5, while PS-7 was 2-fold more active than PS-5 against Enterobacter, Klebsiella, Proteus, Serratia and Escherichia coli. The therapeutic effect of PS-6 seemed slightly less than that of PS-5 in an experimental infection with Staph. aureus Smith in mice.

Chemical modification of deltamycins. I. 4''-O-acyl analogs of deltamycins.

Using 4''-O-deacyldeltamycin as a starting material, various 4''-O-acyl derivatives were chemically synthesized by the following scheme: 2'-O-acetylation leads to 4''-O-acylation leads to 2'-O-deacetylation. 4''-O-Deacyldeltamycin is produced during the fermentation of deltamycin producing organisms or can be prepared by the biological deacylation of the deltamycins. 4''-O-Phenylacetyl-4''-O-deacyldeltamycin (PAD) showed good activity against various bacteria and mycoplasma. Among para-substituted PAD derivatives, NPAD (p-nitrophenylacetyl-) and SPAD (p-methylsulfonylphenylacetyl-) showed increased potency as compared to PAD against certain bacteria. The PAD was evaluated by in vivo experiments for plasma levels in mice and dogs and curative activity on the infected mice with Staphylococcus aureus Smith by subcutaneous or oral administration.

Deltamycins, new macrolide antibiotics. III. Chemical structures.

The structures of deltamycins A1,A2,A3 and A4 belonging to the basic macrolide family of antibiotics were determined mainly from their spectral properties. Deltamycin A4 was identified as carbomycin A having an isovaleryl group on the mycarose moiety of the molecule. Deltamycin A1,A2 and A3 possess similarities to the structure of deltamycin A4, but they have acetyl, propionyl and n-butyryl group, respectively, in the place of isovaleryl group of deltamycin A4. These structures were confirmed by chemical synthesis from deltamycin X (4''-O-deacyldeltamycin) and the corresponding acyl chlorides.

PS-5, a new beta-lactam antibiotic. II. Antimicrobial activity.

PS-5, a new beta-lactam antibiotic, has relatively potent antimicrobial activity against Gram-positive and Gram-negative bacteria, especially the Enterobacter groups, Serratia marcescens, the Proteus groups and Klebsiella pneumoniae. The activity of PS-5 against many beta-lactamase-producing organisms is greater than that of cefoxitin or cefazolin. PS-5 has good therapeutic activity in mice infected with Staphylococcus aureus Smith or Enterobacter cloacae 45.

PS-6 and PS-7, new beta-lactam antibiotics. Isolation, physicochemical properties and structures.

Antibiotics PS-6 and PS-7 which are shown to be 5R,6R-3-(2-acetamido)ethylthio-6-isopropyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene- 2-carboxylic acid and 5R,6R-3-(E)-(2-acetamido) vinylthio-6-ethyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid respectively, are new beta-lactam compounds isolated from fermentation broths of Streptomyces cremeus subsp. auratilis A271, S. fulvoviridis A933, S. olivaceus ATCC 31126 and S. flavogriseus NRRL 8139. Fermentation, isolation, physicochemical properties and structures of antibiotics PS-6 and PS-7 are described.

PS-5, a new beta-lactam antibiotic. I. Taxonomy of the producing organism, isolation and physico-chemical properties.

Antibiotic PS-5 is a new beta-lactam antibiotic isolated from fermentation broths of Streptomyces sp. strain A271. The strain was considered to be a new subspecies of Streptomyces cremeus and the name, Streptomyces cremeus subsp. auratilis, was proposed. Fermentative production, isolation and physico-chemical properties of PS-5 are described.