Sleep tonus inversion: a feature of juvenile dystonic parkinsonism

Polysomnographic monitoring of a 16-year-old girl suffering from dopa-responsive dystonic parkinsonism showed a change in the distribution of muscle activity in thigh muscles during different stages of sleep. The hamstring muscles were hypertonic at sleep onset compared with the vastus lateralis of the quadriceps muscles. At the third sleep cycle of each of the 2 nights, the time at which sleep benefit becomes clinically evident, the hypertonia in the hamstring muscles was reversed and the vastus lateralis became more hypertonic. It is suggested that the muscle tonus inversion marks the moment at which the sleep process alleviates the dystonic parkinsonian state manifested at wakefulness as a circardian fluctuation. According to our data, the flexor-extensor tonus inversion during sleep was not yet described in the literature, and may be an associated feature of dopa-responsive dystonic parkinsonism.     

Intraventricular administration of l-kynurenine and kynuramine facilitates lordosis in the female rat

Intraventricular administration of the tryptophan metabolites l-kynurenine (2-32 micrograms) and kynuramine (0.064-8 micrograms) facilitated lordosis behavior in estrogen-primed ovariectomized rats. The facilitatory effects of these drugs were not attenuated by pretreatment with the progesterone antagonist RU 38486, indicating that the effects were not mediated by release of adrenal progesterone. It is suggested that l-kynurenine and kynuramine may serve a physiological role in the modulation of female sexual behavior.     

Atypical presentation of empyema of the gall bladder

A case of empyema of the gall bladder complicated by liver abscesses is reported. The mode of presentation was atypical for both the empyema and the abscesses and computed tomography (CT) played a significant role in the diagnosis and management.     

Segmental homologies among reticulospinal neurons in the hindbrain of the zebrafish larva

We have examined the morphology of identified reticulospinal neurons in larval zebrafish by retrogradely labeling them with horseradish peroxidase. We described the morphology of 27 different types of reticulospinal neurons found in the hindbrain 5 days after fertilization. Nineteen of these types are present as single identified neurons on each side of the brain; the others are present as pairs or small groups of cells. The hindbrain reticulospinal neurons are present in seven bilateral clusters that are spaced periodically along the neuraxis. Each cluster contains two to five different types of reticulospinal neurons. Cells with similar morphological features are found in adjacent clusters. By considering cell position within the cluster and axon pathway, nearly all of the cells can be assigned to one of about seven serially repeated classes. Independent morphological features of the cells support the same classification. We propose that the clusters represent hindbrain segments and that the neurons of the same class that are present in the different clusters are segmental homologues. Assuming that this series evolved by successive duplications and divergence of the primitive segments, we have analyzed the changes that may have occurred during the evolution of each new segment. Changes between ipsilaterally and contralaterally projecting axons may have occurred several times during the evolution of the series. In addition, cells may have been added or deleted.