The addition of clonidine to prilocaine for intravenous regional anaesthesia.

The effect of the addition of clonidine 2 micrograms kg-1 to prilocaine 0.5% for intravenous regional anaesthesia (IVRA) in the arm was investigated in 56 healthy patients using a randomized, double-blind study. The characteristics of the sensory and motor block, quality of analgesia, development of post-operative pain sensations and haemodynamic variables were studied in three groups (IVRA with prilocaine, IVRA with prilocaine and clonidine, IVRA with prilocaine and systemic application of clonidine at tourniquet release). There were no significant differences between the groups concerning the onset and recovery characteristics of sensory and motor blockade, post-operative pain or side effects. In those patients receiving clonidine, mean arterial pressure decreased significantly (24-28%, respectively) after tourniquet release, while heart rate remained unchanged. Clonidine as an adjunct to prilocaine seems to be of limited benefit during and after intravenous regional anaesthesia.

Plasma levels of androstenedione, epitestosterone, testosterone and oestrogens in cows at parturition.

The concentration of total unconjugated oestrogens in the peripheral plasma of cows increased from 2.00 +/- 0.20 (S.E.M.) ng/ml 7 days before to 3.87 +/- 0.50 ng/ml 1 day before parturition and declined to values below 0.30 ng/ml on day 2 post partum. The concentrations of androstenedione, epitestosterone and testosterone remained approximately constant at 0.90 +/- 0.10, 0.92 +/- 0.08 and 0.40 +/- 0.20 ng/ml respectively during the last week of pregnancy. After parturition the concentration of the three androgens declined rapidly. Similar to data obtained in goats we did not find a marked increase in androgen levels in the peripheral blood of cows before parturition.

[Localization of beta-n-acetylhexosaminidase in stallion epididymis (author's transl)]. / Untersuchungen über die Verteilung der beta-N-Acetylhexosaminidase im Nebenhoden des Hengstes.

The localization of beta-N-acetylhexosaminidase activity in 6 different segments of the epididymis was investigated in 8 stallions using biochemical and histochemical methods. The highest enzyme activity was found in segment D while the other segments displayed a much weaker reaction There was no or only low enzyme activity present in the epididymal fluid of the proximal 3 segments, whereas it was high in the distal 3 segments. The biological function of beta-N-acetylhexosaminidase in the epididymis is discussed briefly.

Effect of immunization of male rabbits against androstenedione.

After active immunization of male rabbits against androstenedione and with increasing antibody titre the concentration of androstenedione and testosterone in peripheral blood increased more than 1000-fold resp. 20-fold above values of control animals. On histological examination of the testes a marked Leydig's cell hyperplasia was found, though there was no difference in testis weight.

In vitro conversion of steroid hormones in bovine ovarian follicles.

In bovine ovarian follicles in vitro conversion of androstenedione and oestrone into oestradiol-17 beta, and of oestradiol-17 beta into oestrone was observed. There was no in vitro conversion of pregnenolone, progesterone, dehydroepiandrosterone and testosterone.

Effects of the B-cell activators lipid A and dextran sulphate on the antibody response to sheep red blood cells in piglets.

The in vivo effects of Lipid A and dextran sulphate on the antibody response to the thymus-dependent antigen SRBC in piglets are reported. No alteration of the low primary antibody response was observed with any of the B-cell activators. However, both substances induced an increase in antibody titre after secondary challenge with the antigen, which was shown to be of the IgG class. An activation of immunological memory in the absence of primary antibody response is suggested.

Development of peripheral B and T lymphocytes in piglets.

The percentage of B and T lymphocytes in the peripheral blood of piglets during their first 35 days of life was estimated by means of the immunofluorescence-labelled anti-L chains sera and the spontaneous E-rosette techniques. The mean values obtained for adult pigs PBL were 23.8 +/- 10.2% of B and 38.0 +/- 8.4% of T lymphocytes. The piglets showed a linear increase for the B lymphocytes starting from a mean value of 4% observed for the newborns. The trend of the T lymphocytes was represented by a bimodal curve. It starts for newborns at 3% and shows a change in shape by the 10th day. It is suggested that the piglets have adult levels of B and T lymphocytes by the time of weaning.

Isolation of porcine colostral immunoglobulins and preparation of monospecific anti-gamma, anti-alpha, and anti-mu chain antibodies using agarose-linked immunosorbents.

A simple method for the simultaneous isolation of IgG2, IgG1, IgA and IgM from porcine colostral whey is described. It makes use of DEAE-cellulose chromatography followed by repeated Sepharose 6B exclusion chromatography after the removal of fat, casein and lipoproteins, Fused rocket immunoelectrophoresis is used to show the elution patterns of each immunoglobulin class. In addition, the prepation of monospecific anti-gamma, anti-alpha and anti-mu sera by means of agarose-linked immunoadsorbents is also described.

Escherichia coli enterotoxin: purification, partial characterization, and immunological observations.

Enterotoxin, a diarrhea-inducing protein elaborated by pathogenic Escherichia coli strains, was isolated from the supernate of fermenter cultures of E. coli strain P263, a porcine enteropathogen. Purification involved chromatography and preparative isotachophoresis. The resulting product appeared to be pure according to immunoelectrophoretic, disc electrophoretic, ultracentrifugal, and immunologic criteria. The enterotoxin had an apparent molecular weight of 102,000 daltons, and its isoelectric point was 6.90. The isolated product was active in inducing experimental diarrhea in adult rabbits and piglets. In small dosage it also elicited a drastic increase in adenylate cyclase activity in broken-cell preparations of cat heart tissue. The enterotoxin activity was acid labile and was destroyed by heat (65 C for 30 min). It is suggested that the heat-stable enterotoxin was derived from heat-labile enterotoxin by complexing with endotoxin or with capsular material in the culture supernatant. The antigenic relations between the heat-labile enterotoxins of enteropathogenic E. coli strains of different serological types and different host adaptations, as well as between the E. coli enterotoxin and that of Vibrio cholerae, were investigated.