Menstrual factors in sleep.

The changing endocrine profile in premenopausal women alters aspects of sleep and circadian rhythms. Subjectively women appear to feel a greater need for sleep and report poor and insufficient sleep more often than men. This greater sleep requirement may manifest with a higher amplitude of slow-wave sleep in the EEG in women.

Activated B cells express increased levels of costimulatory molecules in young autoimmune NZB and (NZB x NZW)F(1) mice.

Polyclonal B cell activation is a hallmark of autoimmune disease in NZB and (NZB x NZW)F(1) (NZB/W) mice. However, the mechanism by which this activated cell subset facilitates disease development is unknown. We recently showed that resting B cells from these mice demonstrate enhanced expression of costimulatory molecules in response to CD40 crosslinking (Jongstra-Bilen et al.

Autoimmunity develops in lupus-prone NZB mice despite normal T cell tolerance.

NZB mice spontaneously develop an autoimmune disease characterized by production of anti-RBC, -lymphocyte, and -ssDNA Abs. Evidence suggests that the NZB mouse strain has all of the immunologic defects required to produce lupus nephritis but lacks an MHC locus that allows pathogenic anti-dsDNA Ab production. The capacity to produce diverse autoantibodies in these mice raises the possibility that they possess a generalized defect in self-tolerance.

Pallidotomy for Parkinson's disease.

The major motor disturbances in Parkinson's disease are thought to be caused by overactivity of the GABAergic internal segment of the globus pallidus (GPi), which acts as a "brake" on the motor thalamus and the cortical motor system to produce the slowness, rigidity, and poverty of movement characteristic of parkinsonian states. The goal of pallidotomy is to reduce this excessive inhibition on the motor system in patients with Parkinson's disease who continue to be significantly disabled despite pharmacotherapy. GPi can be identified with a high degree of precision through microelectrode recording and stimulation.

Cold-induced pain and prickle in the glabrous and hairy skin.

Little is known concerning the mechanisms underlying the perception of cold pain in humans. An appreciation of these mechanisms is important to understand and possibly treat those disorders in which cold stimuli evoke unpleasant sensations. To study cold pain, I have conducted psychophysical experiments on 16 healthy subjects.

Identification and characterization of neurons with tremor-frequency activity in human globus pallidus.

Many previous studies have demonstrated the existence of neurons with tremor-frequency activity ("tremor cells") in the thalamus of Parkinson's disease (PD) patients and these neurons are presumed to play a role in the pathogenesis of tremor. Since a major input to motor thalamus (Voa and Vop) is from the internal segment of the globus pallidus (GPi), neurons with tremor-frequency activity in motor thalamus may receive input from neurons in GPi. The aim of this study was to quantify the characteristics of tremor cells in human globus pallidus.

Associated postural adjustments are impaired by a lesion of the cortex.

A ballistic movement of one arm may be accompanied by contractions of contralateral postural muscles known as "associated postural adjustments." Ballistic movements are considered to involve the motor cortex, but it is not known where associated postural adjustments are generated. We recorded the EMG activity in the deltoid and latissimus dorsi muscles during ballistic abduction of the arm in 10 normal subjects and five subjects with lesions of the motor cortex.

Psychometric evaluation of the Stanford Sleepiness Scale.

Two assumptions underlying the Stanford Sleepiness Scale (SSS) were evaluated: that the descriptors defining each level of the scale are equivalent ways of characterizing a particular level of sleepiness; and that sleepiness, thus measured, is an unidimensional construct. Twenty-four True/False items were derived from the descriptors at each level of the SSS. This revised scale was administered to 340 undergraduates in a questionnaire which also included: the SSS; four visual analogue scales; items identifying the subject's age, sex, and circadian type; and the time of administration.