Characterization of monoclonal antibodies to ovine tumor necrosis factor-alpha and development of a sensitive immunoassay

Monoclonal antibodies (mAbs) and a polyclonal rabbit antiserum were raised against recombinant ovine tumor necrosis factor-alpha (rovTNF alpha). Ten mAbs specific for rovTNF alpha were isolated and designated TNF1-10. All mAbs were of the IgG1 isotype and reacted with rovTNF alpha in Western blot analysis. Eight of the ten mAbs, TNF1, TNF3-7 and TNF9 and 10, completely blocked the activity of rovTNF alpha and macrophage derived native ovTNF alpha, as measured by their ability to inhibit TNF alpha-mediated lysis of WEHI-164 or L929 cells. In addition, TNF3, -7, -9 and -10 blocked the cytolytic activity of recombinant human TNF alpha (rhuTNF alpha). However, when tested for the ability to inhibit TNF alpha induced thymocyte proliferation, only mAbs TNF1, -3, -5, -7, -9 and -10 could completely block activity. Competitive binding analysis using unlabelled and horseradish peroxidase (HRPO) labelled mAbs indicated that the mAbs could be divided into five groups based on their reactivity with rovTNF alpha. The mAbs were used to develop a sensitive sandwich immunoassay for the detection of ovTNF alpha. All combinations of mAbs and the polyclonal antiserum were tested to determine which pair of antibodies gave the most sensitive assay. The combination of TNF5 as the capture antibody and the polyclonal antiserum gave the most sensitive result, detecting less than 0.24 ng rovTNF alpha ml-1. A similar sensitivity was obtained when TNF4 was used as the capture antibody and TNF10 HRPO labelled mAb as the second antibody. The immunoassay was more sensitive than the WEHI-164 bioassay which had a detection limit of 1 ng ml-1 for rovTNF alpha. This immunoassay also detected glycosylated ovTNF alpha in the supernatant of COS-7 cells which had been transfected with an ovTNF alpha cDNA.     

A biphasic developmental pattern of circulating leptin in the male rhesus macaque (Macaca mulatta)

To help elucidate the physiological role of leptin during somatic and sexual maturation, circulating concentrations of leptin were measured in 36 male rhesus monkeys of ages ranging from 0-20 yr. The body weight of these animals showed a steady increase of approximately 1 kg/yr during the first decade of life and reached a plateau at approximately 13 yr. In contrast, serum leptin concentrations showed a biphasic developmental pattern, which was highlighted by a strong negative correlation with body weight (r = -0.74, P < 0.001) before the onset of puberty (at approximately 3.5 yr) and by a strong positive correlation afterward (r = 0.77, P < 0.001). Overall, the developmental changes in serum leptin concentrations closely mimicked the expected developmental changes in serum testosterone concentrations (r = 0.62, P < 0.001), which were highly elevated at birth, fell to basal levels during the juvenile phase of development, and gradually rose again after the initiation of puberty. However, mean serum leptin concentrations during the peripubertal period itself (3-5 yr) were significantly lower (P < 0.01) than those observed during the first year of life or those observed in fully mature adults (i.e. > 7 yr) (3.5 +/- 0.3, 1.4 +/- 0.2, and 3.3 +/- 0.6 ng/ml, respectively). These data demonstrate that the role of leptin in energy homeostasis of primates is more than a simple linear relationship, being highly dependent upon the developmental age. Furthermore, the data do not support the hypothesis that leptin plays a major role in triggering the onset of puberty in primates, although the strong correlation between serum concentrations of leptin and testosterone suggests that the secretion of these two hormones may be causally linked.     

A nasal foreign body detected on routine orthodontic radiographs

Films used in orthodontics such as lateral cephalograms and orthopantomograms provide excellent visualisation of the maxillary sinuses and the nose, and therefore should be routinely examined for pathology and foreign bodies. We report a case of a long-standing asymptomatic nasal foreign body detected on routine orthodontic films.     

Predicting body weight from body measurements in Asian elephants (Elephas maximus)

Accurate estimates of body weight can be useful in the evaluations of feeding programs, nutritional status and general health, and in calculation of dose levels (such as for anesthesia)-thus providing a valuable tool for captive elephant management. We used body measurements of 75 Asian elephants (Elephas maximus) to predict body weight. Weight, heart girth, height at the withers, body length, and foot-pad circumference were measured. All possible linear regressions of weight on one, two, three, or four body measurements were calculated. The highest correlation with a single measurement was that between heart girth and weight (R2 = 0.90). The data were also divided into age groups (1-13, 18-28, 29-39, and 40-57 yr), and all possible linear regressions were calculated for each group (there were no elephants aged 14-17 yr). Adding body length or pad circumference to heart girth resulted in a slight increase in R2. We conclude that body weight in Asian elephants can be predicted from body measurements and that heart girth is the best predictor. A second body measurement might improve predictive accuracy for some age groups.     

Mild combined immunodeficiency in identical twins

Fourteen adult cats were exercised on a motor-driven treadmill 5 days each week for 6 weeks to determine the effect of exercise conditioning on the intrinsic contractile state of the myocardium. The exercise program was sufficient to produce a cardiovascular training effect manifested by slower exercising heart rates and resting heart rates after atropine by the end of the 6th week. The mechanical function of the isolated right ventricular papillary muscle from exercised cats was compared with that of 17 sedentary adult cats. There were no significant differences between exercised and control cats in in heart weight-body weight ratios, resting and active lenght - tension relations, maximal rate of isometric force development at the peak of the length-tension curve (Lmax), time to peak force at Lmax, maximal force development with paired stimulation and norepinephrine, or force-velocity relations. These results indicate that the intrinsic state of feline myocardium is unaffected by exercise conditioning.     

Hemoglobins Aida (alpha 64 Asp leads to Asn) and D-Los Angeles (beta 121 Glu leads to Gln) in an Asian-Indian family

Hemoglobins D-Los Angeles (beta 121 Gln) and Aida (alpha 64 Asn) were encountered in an Asian Indian, unassociated with any clinical manifestations. These hemoglobins had normal oxygen affinities and were stable to heat and isopropanol. The ratio of alpha chain synthesis to beta chain synthesis was close to unity. The identical change in isoelectric points of the two variants produced an interesting electrophoretic pattern.     

Pharmacoradiography of the gastro intestinal tract (author's transl)

Pharmacoradiography of the digestive system improves often accuracy of diagnostic information compared to conventional X-ray examinations. Pharmacoradiography should be used more often; the examiner has to be familiar with the principal effects and side effects of the pharmaceutica. The present paper gives a short summary about drugs and examination techniques most often used.     

The retinoid ligand 4-oxo-retinoic acid is a highly active modulator of positional specification

Retinoids (vitamin A and its metabolites) are suspected of regulating diverse aspects of growth, differentiation, and patterning during embryogenesis, but many questions remain about the identities and functions of the endogenous active retinoids involved. The pleiotropic effects of retinoids may be explained by the existence of complex signal transduction pathways involving diverse nuclear receptors of the retinoic acid receptor (RAR) and retinoid X receptor (RXR) families, and at least two types of cellular retinoic acid binding proteins (CRABP-I and -II). The different RARs, RXRs, and CRABPs have different expression patterns during vertebrate embryogenesis, suggesting that they each have particular functions. Another level at which fine tuning of retinoid action could occur is the metabolism of vitamin A to active metabolites, which may include all-trans-retinoic acid, all-trans-3,4-didehydroretinoic acid, 9-cis-retinoic acid, and 14-hydroxy-4,14-retroretinol. Formation of the metabolite all-trans-4-oxo-retinoic acid from retinoic acid was considered to be an inactivation pathway during growth and differentiation. We report here that, in contrast, 4-oxo-retinoic acid is a highly active metabolite which can modulate positional specification in early embryos. We also show that this retinoid binds avidly to and activates RAR beta, and that it is available in early embryos. The different activities of 4-oxo-retinoic acid and retinoic acid in modulating positional specification on the one hand, and growth and differentiation on the other, interest us in the possibility that specific retinoid ligands regulate different physiological processes in vivo.