VIP in cerebrospinal fluid of patients with multiple sclerosis

The concentration of VIP was measured radioimmunochemically in cerebrospinal fluid (CSF) from 14 healthy volunteers and from 22 patients with multiple sclerosis. Significantly lower levels of VIP was obtained in the patients (18 +/- 3 pmol/l) than in controls (37 +/- 4 pmol/l). There was no correlation between the level of VIP in CSF and other CSF parameters such as albumin. IgG or cell content; nor between VIP concentration and the physical handicap or neuropsychiatric symptoms. There was a trend towards lower values of VIP in patients with steadily progressing rather than intermittent course of the disease but the difference between the groups was not significant.     

Time of replication of genes responsible for a temperature-sensitive function in a cell cycle-specific ts mutant from a hamster cell line

A method involving short pulses of 5-bromodeoxyuridine (brUdRib) followed by irraidation with 313 nm light was used to locate the time of replication of certain genes during the cell cycle of two cell lines, AF8 and AL106. AF8, a temperature-sensitive mutant of BHK21/13 cells, grows at 33°C but not at 39.5°C. AL106, a hybrid clone of tsAF8 and SV-40 transformed Lesch-Nyhan fibroblasts (LNSV), which retains all hamster chromosomes and one human chromosome (No. 3), has the ability to grow at 39.5°C. AF8 and AL106 cells synchronized at the G₁-S boundary were released from their block and pulsed with brUdRib for 2-hour periods during the S phase. The cells were subsequently irradiated with 313 nm light. Colony-forming efficiency and revertants frequency were studied. Incorporation of brUdRib during the early S phase (0–4 hours from the begining of S), decreased the colony-forming efficiency of AL106 cells both at 33°C and 39.5°C, and also of AF8 cells at 33°C. No AF8 colonies grew at the nonpermissive temperature regardless of the treatment. Thus the time of replication of genes responsible for colony-forming ability was the same in tsAF8 at the permissive temperature and in AL106 at both temperatures. The time of replication of the genes responsible for the ts function in AF8 cells was located by determining the revertants frequency in synchronized AF8 cells pulsed with brUdRib and irradiated during 1- to 2-hour periods of the S phase. Back-mutants were scored by counting the number of clones capable of growing at 39.5°C (nonpermissive for AF8 cells). The highest frequency of induced back-mutations occurred in synchronized AF8 cells pulsed with brUdRib (and irradiated) between two to four hours from the begining of the S phase. Exposure to brUdRib during other periods of the S phase or during G₁ had no effect on the reversion rate. This method can be used to locate the time of replication (in S) of ts genes in other temperature-sensitive mutants or of other specific genes in other conditional mutants.     

Improvement of anther culture technique: Activated charcoal bound in agar medium in combination with liquid medium and elevated CO2 concentration

Anthers of different species of the genera Anemone, Clematis, Papaver and Nicotiana were cultured by floating on a liquid medium which overlay an agarified charcoal medium . This technique proved to be superior to conventional methods i.e. culture on either solid or liquid media. Cold treatment of Anemone anthers for 7 days after inoculation on the double layer medium gave about the same frequency of embryos per anther as corresponding cultures cold treated before inoculation. An elevation of the CO₂ concentration to 2% stimulated embryogenesis in anther cultures of Anemone canadensis, Anemone vitifolia, Papaver setigerum and Papaver radicatum . Cold treatment of cultures of Anemone canadensis inhibited embryogenesis if the ensuing culture was performed in 2% CO_2. On the other hand, cold treatment was stimulating, with an optimum of about 20 days, if the cultures were maintained in normal air. Chemical analysis of untreated anthers of Anemone canadensis showed the presence of abscisic acid (2.2 × 10⁻⁶ g/g anthers). Cold treatment reduced the concentration of abscisic acid to 0.6 × 10⁻⁶ g/g anthers. By use of assays with Lemna gibba as test organism, activated charcoal was shown to adsorb abscisic acid that was added to the medium. Medium treated with charcoal before inoculation of anthers of Anemone canadensis provided to inhibit embryo production.     

Necines of alkaloids in Heliotropium species from Mexico and the U.S.A.

The qualitative and quantitative compositions of necines in plants of 20 Heliotropium species collected in Mexico and the U.S.A. and one species from Spain are reported. Trachelanthamidine, supinidine and retronecine were found in all species after hydrolysis of their alkaloids; lindelofidine was detected in most species, whereas heliotridine only in four. Trachelanthamidine, lindelofidine, and supinidine were dominant in four, two and one species, respectively; retronecine was dominant in 15 species, whereas heliotridine only in one. The dominant necine in H. ternatum was either retronecine or lindelofidine depending on the collection locality. Qualitative as well as quantitative differences depending on the collection locality were found in H. curassavicum. Plants from Oaxaca, Mexico, contained lindelofidine and a pyrrolizidine-diol as major necines, trachelanthamidine as minor, and traces of retronecine. Plants originating from two other localities contained trachelanthamidine (dominant), retronecine, and supinidine. The necine patterns found in the examined species differ significantly from those previously reported for 21 species mainly collected in Asia, the Middle East and Australia.     

Heparin enhances the rate of binding of fibronectin to collagen.

125I-labelled fibronectin is shown to bind to both native and denatured collagen immobilized on Sephadex beads in reactions that exhibit different kinetics. The rates of both reactions were enhanced by the presence of heparin or highly sulphated dextran sulphate but not by other glycosaminoglycans or dextran sulphates having low sulphate contents.     

Studies on plating efficiency and estimation of viability of suspensions of Paracoccidioides brasiliensis yeast cells

Mild sonication was used to obtain single cell suspensions of Paracoccidioides brasiliensis. These cells were intact by microscopic criteria. Direct cell counts in a given inoculum and colony formation on various media were used to determine plating efficiency. Sonicated and nonsonicated cell suspensions were used to study plating efficiency and to estimate viability by means of vital dyes. Methylene blue, Erythrosin B, and Janus green were unreliable when used with P. brasiliensis, but vital dyes were accurate when tested with Candida albicans.Acridine orange gave more meaningful results of viability. Estimates of viability, however, changed significantly as a result of relatively minor alterations in the composition of the suspending medium.In initial experiments, the plating efficiency of P. brasiliensis was dismally low. It descended abruptly with increasing dilution of inoculum. Efficiency was much improved if horse serum was added to brain heart infusion plates or if glucose glycine yeast extract (GGY) plates were incubated at room temperature and mycelial colonies were counted. With the technique we report, current plating efficiency of sonicated suspensions is of the order of 25 %. Our results and procedures have an important bearing upon those studies concerned with in vitro killing of P. brasiliensis in suspensions or with isolating this fungus from clinical or environmental specimens.     

Empirical choice of sampling procedures for optimal research design in the longitudinal study of primate behavior

A method is suggested to evaluate on an empirical basis sampling plans for the longitudinal study of primate behavior in those very common situations in which the mathematical structure of behavior is unknown. The method is based on a randomization procedure applied to a pilot sample of the behavior organized so that cost of implementation of a sampling plan can be evaluated vis á vis the sampling error intrinsic to the plan.     

A COMPARISON BETWEEN FLUOROMETRIC AND MASS FRAGMENTOGRAPHIC DETERMINATIONS OF HOMOVANILLIC ACID AND 5-HYDROXYINDOLEACETIC ACID IN HUMAN CEREBROSPINAL FLUID

HVA and 5-HIAA in human cerebrospinal fluid were quantitatively determined by both fluorometry and mass fragmentography. The homovanillic acid values obtained by fluorometry were significantly lower than those obtained by mass fragmentography (P < 0.05). The correlation coefficient between values for HVA obtained by the two methods was high, r= 0.90. For 5-HIAA the concentrations obtained by the two methods were not significantly different while the correlation coefficient was lower, r= 0.55.