MODULATION OF NEGATIVE WORK OUTPUT FROM A STEERING MUSCLE OF THE BLOWFLY CALLIPHORA VICINA

Of the 17 muscles responsible for flight control in flies, only the first basalar muscle (b1) is known to fire an action potential each and every wing beat at a precise phase of the wing-beat period. The phase of action potentials in the b1 is shifted during turns, implicating the b1 in the control of aerodynamic yaw torque. We used the work loop technique to quantify the effects of phase modulation on the mechanical output of the b1 of the blowfly Calliphora vicina. During cyclic length oscillations at 10 and 50 Hz, the magnitude of positive work output by the b1 was similar to that measured previously from other insect muscles. However, when tested at wing-beat frequency (150 Hz), the net work performed in each cycle was negative. The twitch kinetics of the b1 suggest that negative work output reflects intrinsic specializations of the b1 muscle. Our results suggest that, in addition to a possible role as a passive elastic element, the phase-sensitivity of its mechanical properties may endow the b1 with the capacity to modulate wing-beat kinematics during turning maneuvers.

The diagnostic dilemma of myxedema and madness, axis I and axis II: a longitudinal case report

A patient with presumed chronic paranoid schizophrenia had chronic thyroiditis and Grade I hypothyroidism. Psychosis cleared following treatment with thyroid replacement. The probable presence of two axis II disorders may have contributed to the missed medical diagnosis and the patient's eventual suicide. The personality disorders were a major problem in the patient's medical and psychiatric care. The differential diagnosis among hypothyroidism and primary axis I psychotic and depressive psychopathology has always been problematic. When axis II pathology is also present, the diagnostic dilemma is increased.

False positive indirect fluorescent antibody (IFA) tests for antibody to herpes simplex virus 1. Comparison of four commercially available methods

Four commercially available herpes simplex virus 1 (HSV-1) indirect fluorescent antibody (IFA) kits were compared with the use of sera selected because they were negative for HSV antibody by complement fixation (CF less than 1:8) and by ELISA (less than 1:100). However, 14 of 24 (58.3%) of these HSV-1 antibody-negative sera were positive at greater than or equal to 1:10 with the use of the HSV-1 IFA kit from Electronucleonics, 15 of 24 (62.5%) were positive with the Clinical Sciences HSV-1 IFA kit, 4 of 24 (16.7%) were positive with Zeus Scientific, and 4 of 18 (22.2%) were positive with the Gull Laboratories product. HSV-1 induces Fc receptors that commonly cause false positive IFA tests for HSV antibody. Therefore, further studies were undertaken to determine whether Fc receptors accounted for these false positive results. Staphylococcal protein A (SPA) is known to bind to the Fc portion of human IgG and therefore could be used to distinguish between the binding of an antibody by its Fab or its Fc portion. Thus, when fluorescein isothiocyanate conjugated (FITC) SPA was used as conjugate instead of FITC antibody to human IgG, true HSV-1 antibody-containing sera remained positive, but the false positives identified in the commercial IFA kits did not. The authors conclude that HSV-1-induced Fc receptors are responsible for most of the problem of these false positives and that HSV-1 serology probably should not be done by this type of IFA method until this problem is corrected.