An improved method for cell and spore counts during aerobic cultivation of crystal toxin producingBacillus sphaericus

Summary A simple improved method including sonication treatment is proposed to determine accurate cell and spore counts forBacillus sphaericus, a microorganism which can form cell aggregates. Sonication (10 watt power output) for 40 seconds after dilution of culture broth was effective in dispersing clumps of cells and spores without disruption. This improved method gave approximately 2 times higher cell and spore counts compared with the conventional counting methods (without sonication).     

Fetal breathing movements and lung maturation in the congenitally abnormal human fetus

Fetal breathing movements have been studied in conjunction with features of anatomical and biochemical development of the lung at birth in fetuses with congenital abnormalities affecting the respiratory system. Total absence of fetal breathing movements or abnormal fetal breathing movements were associated with lung hypoplasia and failure of normal surfactant release into saline extracts of lung fluid. Surfactant synthesis was demonstrated regardless of the presence or absence of fetal breathing movements. The study supports the hypothesis that normal fetal breathing movements are important for fetal lung development and suggests that surfactant synthesis and its release are independent. The latter process may be dependent upon fetal breathing movements while the former is not.     

A comparative dynamic study of the effectiveness of gastric cytoprotection by vitamin A, De-Nol, sucralfate and ulcer healing by pirenzepine in patients with chronic gastric ulcer (a multiclinical and randomized study)

The gastric cytoprotective effects of vitamin A, De-Nol and sucralfate were compared with the effectiveness of pirenzepine in healing ulcer in patients with chronic gastric ulcer. A total of 100 patients was randomized into different groups: the patients were treated with antacids, vitamin A (3 X 50.000 IU), De-Nol liquid (4 X 5 ml), sucralfate (4 X 1 g) or pirenzepine (3 X 50 mg). The treatment was continued for 4 weeks. At the beginning, 2 and 4 weeks after starting treatment the patients were subjected to endoscopy and the size of the ulcer was measured planimetrically. The ulcer-healing effect of De-Nol liquid was significantly better than that of the antacids (p less than 0.01). Ulcer size was reduced significantly in all groups (p less than 0.01), however, at the end of the study the gastric ulcers were smallest in the De-Nol treated group (p less than 0.001). The dynamics of ulcer healing in the second week was most favourable in the patients receiving vitamin A (p less than 0.01). The present data point to the cytoprotective effects of De-Nol liquid, vitamin A and sucralfate and to their ability of healing chronic gastric ulcers.     

Formation and regeneration ofHalobacterium spheroplasts

Spheroplasts ofHalobacterium cutirubrum were formed upon suspension of cell pellets in 0.1M MES buffer, pH 7.0, containing 0.5M sucrose, 0.25M NaCl, and 0.01M MgCl₂. The spheroplasts regenerated into rod-shaped bacteria when plated on a complex medium containing 15% (wt/vol) sucrose, undergoing several divisions as spherical bodies before the rod shape developed. The frequency of regeneration was approximately 5% of the total spheroplasts plated. The yield of regenerants was increased significantly (to approximately 35%) when bovine serum albumin was present in the spheroplasting buffer and dilution media. The conditions for spheroplast formation and regeneration inH. cutirubrum were also found effective forHalobacterium salinarium but not forHalobacterium halobium.NRCC Paper no. 23080.     

13C-NMR of double and triple bond carbon atoms of unsaturated fatty acid methyl esters

The carbon magnetic resonance spectra of many fatty acid methyl esters with cis and trans double bonds and triple bonds at various positions and in many different combinations have been investigated.The influence of the ester group on double and triple bonds in the fatty acid chain depends strongly on the positions of these bonds. For a given position the influence is constant, even if one or more other double or triple bonds are present.Together with the evaluated chemical shift parameters for the effects of double and triple bonds on each other, complete assignments are possible and spectra of various types of unsaturated esters can be predicted with high accuracy (±0.1 ppm).     

An ultrastructural examination of everted rat jejunum

Male, albino, Sprague-Dawley rats were sacrificed by cervical separation. Segments of jejunum were excised, everted and examined with the electron microscope. Examination of tissue fixed immediately after eversion revealed the following changes as compared to non-everted segments fixed $\text{in}$$\text{situ}$ and $\text{in}$$\text{vitro}$: 1) an increase in the length of microvilli from (mean ± S. E.) 0.991 ± 0.011μ for normal tissue to 1.389 ± 0.023μ for everted tissue, 2) an increase in width of microvilli from (mean ± S. E.) 0.089 ± 0.001μ for normal tissue to 0.097 ± 0.001μ for everted tissue, 3) an increase in length and number of lateral membrane interdigitations, and 4) the appearance of intercellular “lakes” in the lateral spaces. The above changes are in those structures hypothesized to be involved with salt and water transport across epithelia and may reflect altered transport rates $\text{in}$$\text{vitro}$ as compared to $\text{in}$$\text{vivo}$.     

Comparison of a lipophilic cation and microelectrodes to measure membrane potentials of the giant-celled algae,Chara australis (Charophyta) andGriffithsia monilis (Rhodophyta)

Summary The vacuolar equilibrium potential of the lipophilic cation TPMP⁺ (triphenyl methyl phosphonium) in the giant algaeChara australis andGriffithsia monilis was directly measured. The TPMP⁺ equilibrium potential was approximately 100mV less negative than the measured vacuolar electrical potential. Thus TPMP⁺ does not act as a probe of the vacuolar electrical potential and appears to be extruded against an electrochemical gradient. Measurement of the plasmalemma equilibrium potential of TPMP⁺ showed that extrusion of TPMP⁺ apparently occurred at both the tonoplast and plasmalemma inChara and at the plasmalemma inGriffithsia. It is concluded that TPMP⁺ cannot be used as a membrane potential probe inChara orGriffithsia.     

Binding of radioactively labeled saxitoxin to the squid giant axon

Summary The binding of saxitoxin, a specific inhibitor of the sodium conductance in excitable membranes, has been measured in giant axons from the squid,Loligo pealei. Binding was studied by labeling saxitoxin with tritium, using a solvent-exchange technique, and measuring the toxin uptake by liquid scintillation counting. Total toxin binding is the sum of a saturable, hyperbolic binding component, with a dissociation constant at 2–4°C of 4.3±1.7nm (meanse), and a linear, nonsaturable component. The density of saturable binding sites is 166±20.4 m^–2. From this density and published values of the maximum sodium conductance, the conductance per toxin site is estimated to be about 7 pS, assuming sequential activation and inactivation processes (F. Bezanilla & C.M. Armstrong, 1977,J. Gen. Physiol. 70: 549). This single site conductance value of 7 pS is in close agreement with estimates of the conductance of one open sodium channel from measurements of gating currents and of noise on squid giant axons, and is consistent with the hypothesis that one saxitoxin molecule binds to one sodium channel.     

The composition of intracellular granules from the metal-accumulating cells of the common garden snail (Helix aspersa).

Certain cells in the hepatopancreas of the common garden snail (Helix aspersa) contain intracellular granules that are sites of metal-ion accumulation. These granules have been extracted and investigated by u.v. and i.r. spectroscopy, atomic-absorption spectroscopy, X-ray microanalysis, thermogravimetric analysis, enzymic assay and microanalysis. The deposits contain about 18% (w/w) water, 5% (w/w) organic matter and 76% (w/w) inorganic material of which the main components are Ca2+, Mg2+ and P2O7(4)-. The possible origin of these granules is discussed, as is their role in detoxifying heavy-metal ions.