Standardization of a new batch of purified tuberculin (PPD) intended for international use

A new batch of PPD tuberculin, RT 23, prepared at the request of UNICEF by the Statens Seruminstitut, Copenhagen, has been compared with previous batches of tuberculin from the Statens Seruminstitut and with the International Standard for the Purified Protein Derivative of Mammalian Tuberculin. The comparisons were made by intradermal tuberculin testing. The majority of tests were carried out in human subjects with various types and levels of tuberculin sensitivity—namely, tuberculous patients in the Netherlands; BCG-vaccinated as well as spontaneously tuberculin-sensitive army recruits in the Netherlands; BCG-vaccinated schoolchildren in Denmark; population groups in the tropics (Mauritius and Nigeria) including a high proportion of persons with low-grade sensitivity. In addition, comparisons were made in guinea-pigs sensitized in different ways.     

Stability of purified tuberculin in high dilution

The authors have investigated the effect of storage on the potency of 5 TU dilutions (5 TU per 0.1 ml) of the purified tuberculin RT 19-21 (Statens Seruminstitut, Copenhagen).     

Localization of fibrinolytic activity during tooth eruption in rat

abstract — The fibrinolytic activity of erupting teeth and their surrounding tissues was studied in 14 young rats with a modification of the histochemical fibrin slide technique. Frozen tape-carried sections were coated with plasminogen-rich or plasminogen-poor fibrinogen, coagulated and incubated for 5 min to 1 h at 37°C. In the plasminogen-rich fibrin, zones of lysis were produced within a few minutes, indicating release of tissue activator of the fibrinolytic system. Distinct fibrinolysis was localized to periosteum as well as to predentin and odontoblasts. Zones of lysis were also observed in relation to some vessel walls, but those of the pulp and the periapical connective tissue did not show any fibrinolytic activity.     

Hemodynamic Effects of Loud Noise before and after Central Sympathetic Nervous Stimulation

ABSTRACT. The hemodynamic effects of loud noise after central α₂-adrenoceptor stimulation were studied in 13 patients with mild (WHO 1) essential hypertension. The patients were randomized (double-blind) to treatment with either placebo or guanfacine 1–2 mg for four weeks and then crossed over and treated for another four weeks. All patients were exposed to a loud broad-band noise (105 dBA for 30 min) and all were studied both on placebo and guanfacine. Guanfacine significantly reduced the resting blood pressure from 141/92 to 134/ 88 mmHg (p<0.01) as well as heart rate at rest from 63 to 58 beats/min (p<0.05). Noise stimulation caused a significant increase in blood pressure and resistance in the placebo-treated group, while cardiac output decreased significantly. Pretreatment for one month with the central α₂-adrenoceptor stimulating agent guanfacine did not block the noise-induced pressor response nor the increase in peripheral resistance. A significant decrease in stroke volume was observed and cardiac output also tended to decrease in this group. It could be concluded that loud noise is a potent pressor stimulus which causes vasoconstriction and that the blood pressure response during noise could not be blocked by the centrally acting an-tihypertensive agent guanfacine. Since noise causes vasoconstriction it also induces an increased tone in the small arteries and, if the noise stimulus is sufficiently strong and repeated for a long time, it might cause structural changes in the resistance vessels and permanent arterial hypertension in humans.     

Intestinal Permeability in Small Children during and after Rotavirus Diarrhoea Assessed with Different-Size Polyethyleneglycols (PEG 400 and PEG 1000)

ABSTRACT. The permeability properties of the small intestinal mucosa was investigated in nine previously healthy children with acute diarrhoea due to rotavirus. The investigation was performed after intake of a mixture in water of polyethyleneglycol molecules (PEG 400 and 1000) ranging from 282 to 1250 dalton in molecular weight. The 6-h urinary recovery of the PEGs was determined with high performance liquid chromatography and used to assess the permeability characteristics of the intestine. The patients served as their own controls and were investigated in the same manner after recovery 3-5 weeks later. A significantly lower urinary recovery of PEG was noted for all molecular sizes (326-1206 dalton) during acute diarrhoea in comparison with the results obtained after recovery ( p <0.001-0.1). There was also a relatively lesser change in the urinary recovery of larger PEG molecules during infection, as reflected by a higher recovery ratio between 1074 and 370 dalton PEGs. The results indicate profound changes in the permeability characteristics of the intestine during acute rotavirus diarrhoea.