Toxicity of co-trimoxazole in nutritional haematinic deficiency

A woman of 47 habituated to analgesics and living on an inadequate diet was deficient in iron, folate and vitamin B₁₂. Treatment of pyelonephritis with co-trimoxazole precipitated pancytopenia with a megaloblastic bone marrow. She recovered following withdrawal of the drug and administration of iron, folate and vitamin B₁₂.

The relationship between the magnesium concentration in the dialysis fluid used and in the plasma and erythrocytes of patients with chronic renal failure being treated by regular haemodialysis

1. Plasma and erythrocyte magnesium concentrations have been determined in fifty-five patients on regular haemodialysis and in thirty-two healthy subjects. The dialysis fluid magnesium concentrations of the former were 0·58, 0·9 and 1·73 mm.

2. There was a linear correlation between the plasma and erythrocyte magnesium concentrations of normal subjects and dialysed patients whose dialysis fluid contained 0·58 and 0·9 mm-magnesium and who were treated by dialysis for at least 3 months. This correlation was otherwise independent of the time the patients had been treated by dialysis.

3. There was a linear correlation between the dialysis fluid and the predialysis plasma magnesium concentrations in all dialysed patients, except that, when the dialysis fluid magnesium was increased, a certain period of treatment was necessary before the new equilibrium was reached.

4. An unusually high magnesium concentration in the dialysis fluid for regular haemodialysis may benefit such patients in view of the known effect of an increased plasma magnesium concentration upon the parathyroid function.

Air embolism during haemodialysis

Two fatal and five non-fatal episodes of air embolism occurred in the course of 14,000 haemodialyses. Air entered the circuit through the infusion bottle, the heparin syringe or line, or the blood pump insert. Emergency treatment with posture, oxygen, dextran infusion, and dexamethasone was apparently successful in reversing some of the manifestations. Prevention depends partly on better design of equipment and partly on the incorporation in the haemodialysis circuit of devices which detect air and prevent it from reaching the patient. Such monitors are not in general use in the United Kingdom and those currently available are far from infallible. We describe an alternative system incorporating a floating valve in the bubble trap.

Bayliss and Starling and the happy fellowship of physiologists

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Factors Affecting Viability of Spore Inoculum In Peronospora Tabagina Adam and Lesion Production In tobacco Plants

Spores of P. tabacina lose viability when in low concentrations in water. The most rapid rate of loss, from 99 to 50% germination in 3 hr, was at 15 and 20�C followed by decreasing rates for 10, 30, 5, and 25�C in that order. At 37�5 and 35�C a few spores survived for 30-60 min.

Factors Affecting Viability of Spore Inooulum In Peronospora Tabacina Adam and Lesion Produotion In tobaooo Plants

Inocula containing spores of P. tabacina were used as sprays or drops on leaves of tobacco plants to determine the effect of various treatments on lesion production.

Effect of inoculum spore load, length of infection period, and leaf washing on occurrence of Peronospora tabacina Adam, (blue mould) of tobacco

Leaves of tobacco plants cv. Virginia Gold were spray-inoculated with different concentrations of spores of Peronospora tabacina strain APT1 and kept wet for 2 to 16 hr. Incubation period and occurrence of the disease on leaves were related to spore concentration, length of the infection period, temperature, and leaf position. The length of the incubation period increased from approximately 3 to 8 days with decrease in spore number. There was a similar increase with decrease in the length of the infection period and with low temperatures. The number of disease lesions increased with spore number in the inoculum and with increase in the length of the infection period up to 8 hr; it was about 100% higher on washed than on unwashed leaves. All leaves of washed plants had the same number of lesions but with unwashed plants, the lowest leaf had the most lesions and the uppermost the least. In a limited series of experiments with APT2 on cv. Virginia Gold and cv. Sol, the results were similar to those reported for APT1. The host–pathogen reaction was modified by spore load and temperature, the result being a range of symptoms; this indicates the need for caution in the use of symptoms as a means for distinguishing between different strains of the pathogen and between levels of resistance. High spore concentrations and infection periods of 4 hr or longer were necessary for extensive occurrence of the pathogen in leaves.

Resistance of seedlings of Nicotiana species to Peronospora tabacina Adam

Seedlings of Nicotiana species of Australian and American origin were tested for resistance to an Australian strain of P. tabacina. American species were less resistant than Australian species and differences in 12 results of similar tests in both countries could have been due to differences in the pathogen or in the seed lines tested. The data suggest that the pathogen would have difficult in surviving on the highly resistant Australian species of Nicotiana in their natural arid habitat. Field observations have shown that survival occurs on the introduced susceptible species N. tabacum and N. glauca.

Dissemination of Conidia of Peronospora Tabacina Adam

Conidia of P. tabacina in the atmosphere of tobacco plots and glass-houses were trapped by means of a Hirst spore trap.

A study of the virus diseases "Big bud" of tomato and "Yellow Dwarf" of tobacco

The two virus diseases "big bud" of tomato and "yellow dwarf" of tobacco are transmitted by the same insect vector. Both were transmitted by grafting but not by sap inoculation. Big bud but not yellow dwarf was transmitted by dodder. Nicotiana glauca Graham was a symptomless carrier of both viruses. Potato was infected by big bud but not by yellow dwarf. Evidence from experiments and field observations indicates that big-bud transmission occurs during summer whereas yellow-dwarf infection can occur throughout the year. From this and other evidence (anatomical, lack of cross protective power, symptoms) it is concluded that the two diseases are caused by different viruses.

Yellow dwarf of tobacco in Australia. IV. Some host plants of the virus

Yellow dwarf of tobacco was transmitted by grafting to six species of the Solanaceae. The results of preliminary transmission experiments with the insect vector indicated that three commonly occurring weeds were probably autumn-spring host plants of the virus.