Myasthenia gravis (MG) is strongly associated with antibodies to acetylcholine receptor (AChR), whereas the extent of T cell involvement is not settled. The number of cells secreting interferon-gamma (IFN-'y) in response to AChR during 48 h culture of blood mononuclear cells (PBL) may reflect AChR-reactive T cells. Using an immunospot assay, we detected such cells in 23 of 30 patients with MG at a mean number of 1 per 33.333 PBL. AChR-reactive T cells were also found in patients with other neurological diseases (OND) and in healthy subjects but at lower frequencies and numbers. The T cell response to purified protein derivative and to PHA, and also to two major myelin proteins (basic protein and proteolipid protein) did not differ between MG and the two control groups, underlining the specificity ofan augmented T cell reactivity to AChR in MG. Evaluation of the B cell response by enumerating anti-AChR IgG antibody secreting cells revealed such cells in 27 of 28 patients with MG at a mean value of 1 per 14,085 PBL. Cells secreting anti-AChR antibodies of the IgA and IgM isotypes were also detected in MG, but less frequently, at lower numbers, and only in conjunction with IgG antibody secreting cells. Anti-AChR antibody secreting cells were also found among patient with OND and in healthy controls, but at lower frequencies and numbers. These data confirm that AChR is a major target for autoimmune response in MG. (J. Clin. Invest. 1991. 87:2191-2196

Inadequate floor properties are considered the primary cause of the majority of claw disorders in pigs but to date no clear relationship has been found between claw disorders and floor properties such as friction and surface abrasiveness. To determine this relationship, the factors controlling pig gait must be characterised.This study examined unprovoked pig gait on a concrete floor in clean conditions and compared it with gait in fouled floor conditions. Kinematics were used to record gait parameters such as walking speed, stride length, swing and stance time, stride elevation together with limb support phases, gait symmetry, diagonality and duty factor.On clean floors, pigs had an unprovoked symmetrical gait with alternating two-and three-beat support phases and a high rate of diagonality. Stride length, swing and stance time and stride elevation showed little variation. Pigs altered their gait in accordance with floor conditions to maintain gait control by reducing walking speed, lowering diagonality and employing more three-limb support phases. Pigs also shortened their stride length and prolonged their stance time.

Eight experiments were conducted to determine the effect of a single administration of amperozide on agonistic behavior and growth performance in newly mixed, restricted-fed pigs. Two hundred 12-wk-old pigs were used in a 4-wk trial (Exp. 1) to investigate the effect of amperozide on agonistic behavior and performance. The pigs were assigned to each pen on the basis of body weight and sex, ensuring that pigs in each pen were unacquainted. Each pig was weighed individually on d 3, 7 and 28. Agonistic behavior was quantified by counting bite and slash marks on each pig at 8, 26 and 48 h after penning. An i.m. injection of amperozide immediately before mixing the pigs reduced the physical damage (P less than .001) at each time point. There was no evidence of amperozide causing either sedation or motor disturbances. On the average, amperozide treatment improved (P less than .001) daily gain in the 4-wk study period by 70 g (17%). In Exp. 2 to 8, 1,648 pigs growing from approximately 20 to 100 kg body weight were used to determine the effect of amperozide on weight gain. Pigs were penned in groups of 9 to 11, randomly assigned to each pen on the basis of sex. Each pig was weighed individually after penning, on d 35 and at slaughter. Untreated control pigs had a poorer growth performance than did amperozide-treated pigs. During the first 5 wk postpenning average daily gain was improved (P less than .001) by 90 g (26%) in pigs receiving a single oral administration of amperozide at penning.(ABSTRACT TRUNCATED AT 250 WORDS)

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SUMMARYBy two-colour fiow cytometric analysis, we found increased numbers of B cells co-expressing ihc pan-T cell marker CD5 and the B cell marker CDI9 in cerebrospinal fluid (CSK) of 21 patienis with multiple sclerosis (MS), compared with 17 control subjects with muscular tension headache. Only one patient with MS, but nine controls lacked CD3*^ B cells in CSF. This difference was not observed in peripheral blood. Numbers of CD5* 19+ Bcells were increased in CSF compared with blood in MS, but not in the controls. In both groups, CD5M9* B cells were not restricted to small resting lymphocytes, but were also found among larger-sized lymphocytes. The relative density of CD5 molecules and ofCD19 molecules was iowcr in CD5' 19' than in CD5 19' B cells and CD5^ 19 T cells. CD5 • B cells arc assumed to be responsible for autoanlibody produclion. and our results suggest a pathogenetic role of such ceils, predominantly within the central nervous system, in MS.