Thiostrepton-resistant mutants of Bacillus subtilis: Localization of resistance to the 50S subunit

Summary Sexual crosses were studied between mutants ofPhycomyces blakesleeanus with abnormal phototropism (phenotypemad). Recombination frequencies were determined among five genesmadA tomadE. No clear evidence was found for linkage between any of the genes. Inconsistent results in crosses involvingmadC are attributed to nonisogenicity between the particular strains used. Onemad strain was discovered to be a double mutant. A new gene, tentatively designatedmadG, was segregated from a cross involving that strain.     

Cap formation on lymphocytes from patients with leukemic diseases induced by four different lectins.

When ficoll purified peripheral blood lymphocytes were treated with fluorescein conjugated lectins from lentils (LCH), castor beans (RCA) and phaseolus coccineus beans (L-and E-PHA) for 15 min and the percentages of the cap forming cells were examined, the values of leukemic lymphocytes were reduced compared to the values obtained with normal lymphocytes. The reduction was more than half in patients with acute and chronic myelogenous leukemia and immunoblastoma, it was only one quarter in patients with chronic lymphocytic leukemia, Hodgkin's disease and lymphosarcoma. The lowest number of cap forming cells was found in lymphoblasts of established lymphoblastoid cell lines. The four different lectins showed nearly the same capacity in the induction of caps. After successive binding, the different lectins showed cocapping on the lymphocyte surface.     

Die Hemmung der Isocitrat-Lyase bei Wassermelonenkeimlingen durch Weißlicht

Summary The isocitrate lyase activity (E.C. 4.1.3.1.) from watermelon cotyledons (Citrullus vulgaris Schrad.) is inhibited by white light (Fig. 5). To exclude artefacts during enzyme preparation the following experiments were performed (Table 1 and 2): 1. Mixing of raw extracts from cotyledons of light and dark grown seedlings. 2. Joint homogenization a) of cotyledons from light and dark grown seedlings, b) of purified isocitrate lyase together with cotyledons from light or dark grown seedlings. The total activity corresponded to an amount which was expected for the sum of the individual activities. The results justify the conclusion that the inhibition of the isocitrate lyase by light is real, and that the measured enzyme activities are close to the true enzyme concentrations in the plant tissue. — The relatively slow inhibition of the enzyme activity caused by light seems to be correlated with the formation of the photosynthetic apparatus.     

Mitochondrial DNA mutations in multiple symmetric lipomatosis

Multiple symmetric lipomatosis (MSL) is a rare disorder of middle life characterized by large subcutaneous fat masses around the neck, shoulders and other parts of the trunk. Peripheral neuropathy is a common finding in these predominantly male patients. Employing electrophysiological measures, we found additional signs of central nervous system involvement in a majority of patients. Etiologically, there is an association with mitochondrial dysfunction. In muscle biopsy, we found ragged red fibers in 8 of 12 patients. Molecular genetic analysis revealed multiple deletions of mitochondrial DNA in one patient and the MERRF mutation at nucleotide 8344 in another. In this review, we summarize our clinical, electrophysiological morphological, biochemical and molecular genetic findings in 17 MSL patients, and give a survey of the literature. (Mol Cell Biochem 174: 271–275, 1997)     

Action of a dietary Mg2+ deficiency and overload in the male rat: measurement of certain parameters of testicular and spermatozoan activity

The specific activities of several enzymes were investigated as possible markers of the Mg2+ impact on testicular and spermatozoa glucidic metabolism: no modification was noticed. However, as a reflection of hormonal metabolism, 17 beta-OH steroid-deshydrogenase activity, AMPc and testosterone levels were measured in the testes and showed significant variations.     

Vorläufige Mittheilung über dasCladosporium Rösleri Cattan und den „schwarzen Brenner“ der Rebe

Ohne ZusammenfassungQuesto funghetto fu scoperto primamente dal dottor Rössler sulle viti di Klosterneuburg presso Vienna e fu creduto la forma conidiofora dell aSphaerella vitis Fuck.; nel 1876 veniva studiato dal dottor Cattaneo nel Laboratorio crittogamico di Pavia e da lui denominateClad. Rössleri (richtigRösleri) Pirotta, Funghi parassiti dei Vitigni p. 81.     

Chemo-somatosensory evoked potentials: A sensitive tool to assess conditioned pain modulation?

Background: Chemo-somatosensory evoked potentials (CSSEPs) elicited by chemical stimulation (CO₂ gas) of the nasal mucosa have been shown to be sensitive enough to pick up even weak analgesic effects. With the present study we wanted to investigate whether CSSEPs are also a sensitive tool to capture endogenous pain inhibitory mechanisms elicited by conditioned pain modulation (CPM; where a first conditioning stimulus reduces the sensitivity for a second test stimulus) with a conditioning stimulus of rather low noxious load.

Methods: Seventeen healthy participants were tested for CPM effects (conditioning stimulus: tonic heat pain with intensities around the pain threshold induced via a thermode; test stimulus: chemonasal stimulation (73% and 78% CO₂)) on CSSEPs and on self-report ratings.

Results: We found significant CPM effects in the CSSEPS, with reduced amplitudes and prolonged latencies at several electroencephalogram (EEG) recording positions when using the lower CO₂ concentration (73% CO₂). In contrast to the visible inhibitory effects on the CSSEPs, subjective ratings of the test stimulus did not reflect CPM action.

Discussion: The experimental pain model using CO₂ stimuli to elicit CSSEPs proved to be sensitive enough to capture weak CPM effects elicited by a conditioning stimulus of rather low noxious load. The usage of such mild noxious conditioning stimuli—in contrast to stimuli of higher noxious load (e.g., cold pressor test)—has the advantage that the activation of other types of pain inhibitory mechanisms in parallel (like attentional distraction, stress-induced analgesia) can be avoided.     

Assessment of process variables on 2-ethylhexyl palmitate production using Novozym 435 as catalyst in a solvent-free system

This work reports the optimization of 2-ethylhexyl palmitate production by esterification reaction in a solvent-free system using a commercial lipase as catalyst. For this, a sequential strategy was performed applying three experimental designs. An empirical model was built so as to assess the effects of process variables on the reaction conversion. Afterward, the operating conditions that optimized 2-ethylhexyl palmitate production were determined to be acid to alcohol molar ratio of 1:5.5, 70 °C, 150 rpm and 10.5 wt% of enzyme, leading to a reaction conversion as high as 93%. From this point, a kinetic study was carried out evaluating the influence of acid to alcohol molar ratio, enzyme concentration and temperature on product yield. Results obtained in this step allow to conclude that an excess of alcohol (acid to alcohol molar ratio of 1:6), relatively low enzyme concentration (10 wt%) and temperature of 70 °C led to nearly complete reaction conversion.