Pulmonary injury from proton and conventional radiotherapy as revealed by CT

OBJECTIVE: Although radiation therapy is used in early-stage inoperable lung cancer, it often results in injury to functional lung tissue. A study was undertaken to determine the frequency and severity of pulmonary injury revealed by CT in patients who had undergone conformal proton (to a limited volume) radiation therapy. We compared these findings with those from a group of patients who had undergone a combination of photon and conformal proton (to a larger volume) radiation therapy. CONCLUSION: Proton radiation therapy was associated with a lower frequency of pulmonary injury than the combined regimen. Injury correlated well with the volume of normal lung that was irradiated. Conformal proton radiation therapy appears to be able to reduce the incidence and severity of pulmonary injury revealed by CT.     

Measles control in Israel: a decade of the two-dose policy

BACKGROUND AND METHODS: The introduction of routine measles immunization in Israel in 1967 was followed by a 95% reduction in reported measles incidence. In 1990, a second measles immunization dose was instituted, and up until the end of 1999, 16 birth cohorts were offered the second dose. We present here changes in reported measles incidence in Israel following institution of the two-dose policy. RESULTS: First-dose coverage is 94%, and coverage for the second school-based dose exceeds 95%. A further 90% reduction in measles incidence has been observed and, following a modest national outbreak in 1994, measles incidence for 1995-99 stands at less than 3/100,000/year. CONCLUSIONS: Since measles is highly contagious, very high immunization coverage rates will be required to preserve these accomplishments, and measles elimination is still years away, but there is tentative evidence that measles containment is at hand. Even greater measles control can be anticipated as vaccine immunogenicity improves and successive cohorts of children come under the 2-dose regimen.     

The effects of a permanent and selective depletion of brain catecholamines on the antinociceptive action of morphine

Summary 6-Hydroxydopamine was given to newborn mice. After 60 days their brains were deficient in noradrenaline and dopamine while morphine's antinociceptive action was reduced. 6-Hydroxydopa was administered to adult mice. This depleted brain noradrenaline and reduced morphine's antinociceptive action. Newborn rats received 6-hydroxydopa. After 60 days morphine's antinociceptive action was potentiated, brain noradrenaline was reduced while dopamine had increased. Adult rats were treated with 6-hydroxydopa. This reduced brain noradrenaline but did not affect morphine's antinociceptive action. Guanethidine, which depletes noradrenaline in the peripheral nervous system, was given to newborn animals of both species. It had no effect on morphine's antinociceptive action. It is concluded that in the mouse the antinociceptive action of morphine relies in part on normal brain noradrenaline function and dopamine is not directly involved. In the rat morphine's action is affected by neurotoxic drugs which alter brain dopamine function.     

Structure and function of the neuromuscular junction in young adultmdx mice

Summary Dystrophin, the protein product of the gene responsible for X-linked muscular dystrophies, shares structural features with the cytoskeletal proteins spectrin and -actinin. Like spectrin, it is localized at the cytoplasmic surface of the sarcolemma and is particularly concentrated in the subsynaptic region of the neuromuscular junction.Mdx mice have a profound deficiency of dystrophin and develop a necrotizing myopathy in the first weeks of life. Abnormalities of the neuromuscular junction, including a redistribution of postsynaptic molecules and reduction in synaptic folding, are also observed. We have studied these mice to see whether the lack of dystrophin has a specific effect on the structure and function of their neuromuscular junctions.Using a fore-limb muscle from 8 week oldmdx mice we confirm the previously described postsynaptic structural changes and in addition show that many nerve terminals are abnormally complex. We demonstrate that these structural abnormalities are found exclusively at neuromuscular junctions on regenerated muscle fibres. Despite these structural abnormalities, miniature endplate potential frequency, the quantal content of endplate potentials, the amplitude and time course of miniature endplate currents and the number of acetylcholine receptors at the postsynaptic membrane are normal inmdx mice of this age. We conclude that in themdx mouse the absence of dystrophin from the postsynaptic membrane has little direct effect on the function of the neuromuscular junction but that degeneration and regeneration of muscle fibres leads to remodelling of both its pre- and postsynaptic components.     

Role of globus pallidus GABA and opiate receptors in apomorphine circling in nigro-striatal lesioned rats

Summary The effect of lesioning the ipsilateral globus pallidus (GP) on apomorphine-induced circling in nigrostriatal lesioned rats was investigated. A GP electrolesion almost abolished circling. Drugs that affect GABA and opiate receptors were injected in GP through a cannula. Circling was antagonized by the GABA antagonists picrotoxin and bicuculline, the GABA agonist muscimol and by baclofen. Opiate receptor agonists including morohine, levorphanol, [d-Ala², d-Leu⁵]-enkephalin and -endorphin had no effect on circling in GP. Ethylketazocine caused a pronounced, naloxone-reversible slowing of apomorphine circling. Apomorphine-induced circling behaviour may be modulated by GP GABA receptors and kappa-type opiate receptors.