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AbstractThe brief exposure of recently ovulated mouse oocytes to a dilute solution of ethanol in vitro for 1, 3, or 5 min induced a uniform high incidence of parthenogenetic activation. The majority of parthenogenones developed a single haploid pronucleus after the extrusion of a second polar body. The proportionate incidence of this parthenogenetic class was significantly reduced as the duration of ethanol exposure increased from 1 min to 5 min. There was a concomitant increase in the incidence of parthenogenones that developed two haploid pronuclei following failure of extrusion of the second polar body. Cytogenetic analysis of the ethanol‐induced single‐pronuclear haploid parthenogenones at metaphase of the first cleavage division clearly demonstrated that a significant proportion were aneuploid. The incidence of aneuploidy observed was directly related to the duration of ethanol exposure. G‐band analysis of the aneuploid metaphases revealed that the chromosomes were not randomly involved in the malsegregation events. This observation may be a reflection of the relationship of particular chromosomes to the meiotic spindle apparatus rather than on any specific property of the agent to which they were exposed. It is believed that ethanol disrupts the organisation of cytoskeletal elements and, in particular, interferes with the processes of chromosome segregation at the second meiotic division.

Abstract An orange and an apple juice each containing 250–385 ppm tin were under suspicion of having caused an outbreak of food poisoning in Kuwait in 1967 but did not cause any toxic signs when fed to pigeons, cats and dogs. One cat out of 11 vomited when fed an orange juice containing 540 ppm tin derived from the container, and with juices containing 1370 ppm tin, 20–30% of the cats vomited but none of the dogs was affected. Fruit juices containing 2000 ppm tin caused vomiting in up to 40% of the cats. Modification of orange juices with a high tin content by addition of nitrate or ethanol or by adjustment of the pH from 3 to 6 did not affect the incidence of vomiting. No toxic signs were produced in rats given fruit juices containing added tin salts up to a level of 995 ppm or in rats and cats given aqueous solutions of tin salts (up to 1200 ppm tin) in citric acid. Solid foods containing tin derived from the containers up to the highest level obtainable (470 ppm) had no toxic effect when fed to dogs and cats. Five human volunteers showed no toxic signs after drinking fruit juices containing 498, 540 or 730 ppm tin derived from the containers, but all five had some gastro-intestinal disturbance after drinking a fruit juice containing 1370 ppm tin. A repeat experiment with the latter juice had no effect in four of the volunteers and only mild symptoms in the fifth. In rats and cats, there was no evidence of tin absorption 24 hr after ingestion of fruit juices containing high levels of tin. No tin was recovered from the urine and in the rats 99% was recovered from the faeces. Only minute amounts of tin could be found in the body, apart from the alimentary tract, of a rat that had been given orange juice with a high tin content ad lib. instead of drinking water for 7 days. It is concluded that toxic signs follow the drinking of tin-containing fruit juices by man and cats only with tin levels of approximately 1400 ppm and above, that there is no evidence from these experiments that toxicity is due to the absorption of tin and that the most likely cause is local irritation of the mucous membrane of the alimentary tract.

Endocrinological research on wild animals inhabiting remote areas has been hampered by the need to store plasma samples at subzero temperatures. In an attempt to remedy this logistical issue, we here investigate the use of ethanol as an alternative to freezing for the preservation of steroid and indoleamine hormones in avian plasma. Known quantities of the steroids 5alpha-dihydrotestosterone (DHT), testosterone, 17beta-estradiol, corticosterone, and the indoleamine melatonin were added to a stripped pool of chicken plasma. Samples were either immediately frozen at -40 degrees C, or treated with pure ethanol. Ethanol-treated samples were either immediately frozen, or-to simulate storage conditions at various field locations-left sitting at room temperature for one to two months, or incubated at 36 degrees C for one month before all treatment groups were frozen at -40 degrees C. All samples were then analyzed by radioimmunoassay. For DHT and estradiol there were no differences among treatment groups suggesting that ethanol-treatment is as effective as immediate freezing in preserving plasma steroid concentrations. For testosterone, corticosterone and melatonin ethanol-treated samples differed significantly from immediately frozen samples suggesting that caution is needed when comparing absolute concentrations of hormones between samples preserved in different ways. However, differences among ethanol-treated samples in general were small, demonstrating the feasibility of this preservation method in the field at remote locations.

Melanin obtained from Aureobasidium pullulans and Cladosporium resinae was an efficient biosorbent for copper. Copper uptake could be expressed using various adsorption isotherms; melanin from A. pullulans obeyed Freundlich and Langmuir isotherms whereas C. resinae melanin followed the BET isotherm indicating a more complex type of adsorption than in A. pullulans. In general, uptake capacities of melanin were greater than for intact biomass and the higher uptake by pigmented rather than albino biomass could be correlated with the presence of melanin. Cu2+ was less readily desorbed from melanin by dilute mineral acids than from intact biomass and again, the relative ease of Cu2+ desorption from pre-loaded pigmented or albino biomass was correlated with the presence or absence of melanin. Mg2+ and Zn2+ appeared to be the most effective cations for desorption with Na+ and K+ the least effective. The addition of melanin to a coppercontaining culture of the albino strain of A. pullulans resulted in some reduction of toxicity.

In a double-blind, cross-over study of twenty male volunteers intravenous injection of 0.4 mg naloxone prevented the impairment of psychomotor performance induced by low levels of blood alcohol. The possibility that alcohol produces intoxication by stimulating the release of endogenous opioid peptides should be investigated.

Summary.A simple technique for assessing the Gram positivity of dried smears of bacteria is described. Standardized smears on glass slides are decolourized for a specified time and the colorimetric level of crystal violet loss into the decolourizer taken as a measure of Gram positivity. The technique gives comparative values between strains and has been successfully used in several different experimental conditions.

The aim of this study was to compare the effect of extracorporeal shock wave therapy (ESWT) in patients with chronically painful proximal plantar fasciitis with a further conventional conservative treatment. Forty-seven patients (49 feet) with a previously unsuccessful nonsurgical treatment of at least 6 months were randomized to two groups. Heel cups had to be worn throughout the study. Group 1 (25 heels) was treated immediately with three sessions of ESWT (3000 shock waves/session of 0.2 mJ/mm 2 ) at weekly intervals. The patients of group 2 (24 heels) continued nonsurgical treatment (iontophoresis with diclofenac and an oral nonsteroidal anti-inflammatory drug) for 12 weeks. After this period they were treated using the protocol of group 1. No significant difference of pain and walking time after further nonsurgical treatment (3 months) was seen in group 2. At 12 weeks after ESWT, the pain estimation on the visual analogue scale (VAS) for activities of daily living diminished significantly by 62.9% in group 1 and by 63.0% in group 2. The comfortable walking time had increased significantly in both groups. Two years after ESWT, pain during activities of daily living decreased by 94% in group 1 and by 90% in group 2 on the VAS and the comfortable walking time had increased significantly in both groups.

Boron (B) toxicity symptoms are visible in the form of necrotic spots and may worsen the oxidative stress caused by salinity. Hence, the interactive effects of combined salinity and B toxicity stress on antioxidative activities (TAC, LUPO, SOSA, CAT, and GR) were investigated by novel luminescence assays and standard photometric procedures. Wheat plants grown under hydroponic conditions were treated with 2.5 μM H₃BO₃ (control), 75 mM NaCl, 200 μM H₃BO₃, or 75 mM NaCl + 200 μM H₃BO₃, and analysed 6 weeks after germination. Shoot fresh weight (FW), shoot dry weight (DW), and relative water content (RWC) were significantly reduced, whereas the antioxidative activity of all enzymes was increased under salinity compared with the control. High B application led to necrotic leaf spots but did not influence growth parameters. Following NaCl + B treatment, shoot DW, RWC, SOSA, GR, and CAT activities remained the same compared with NaCl alone, whereas the TAC and LUPO activities were increased under the combined stress compared with NaCl alone. However, shoot FW was significantly reduced under NaCl + B compared with NaCl alone, as an additive effect of combined stress. Thus, we found an adjustment of antioxidative enzyme activity to the interactive effects of NaCl and high B. The stress factor "salt" mainly produced more oxidative stress than that of the factor "high B". Furthermore, addition of higher B in the presence of NaCl increases TAC and LUPO demonstrating that increased LUPO activity is an important physiological response in wheat plants against multiple stresses.