Fusobacterium necrophorum sepsis with cerebral infarction

We have described the case of a 23-month-old female child in whom Fusobacterium sepsis progressed to cerebral infarction despite therapy with intravenous chloramphenicol and ampicillin. Some clinical improvement was noted upon addition of metronidazole to the treatment regimen. The child survived, but has severe neurologic sequelae. Physicians should suspect anaerobic infection in children who have signs of severe neurologic infection and in whom cultures are negative for aerobes. In selected cases, early treatment with metronidazole may be helpful.     

Differential effects of trisomy on brain shape and volume in related aneuploid mouse models

Down syndrome (DS) results from inheritance of three copies of human chromosome 21 (Hsa21). Individuals with DS have a significantly smaller brain size overall and a disproportionately small cerebellum. The small cerebellum is seen in Ts65Dn mice, which have segmental trisomy for orthologs of about half the genes on Hsa21 and provide a genetic model for DS. While small cerebellar size is well-established in mouse and humans, much less is known about the shape of the brain in trisomy. Here we conduct a morphometric analysis of the whole brain and cerebellum in Ts65Dn mice and show that the differences with euploid littermates are largely a function of volume and not of shape. This is not the case in two aneuploid mouse models that have fewer genes orthologous to Hsa21 than Ts65Dn. Ts1Rhr is trisomic for genes corresponding to the so-called Down syndrome critical region (DSCR), which was purported to contain a dosage sensitive gene or genes responsible for many phenotypes of DS. Ms1Rhr is monosomic for the same segment. These models show effects on cerebellum and overall brain that are different from each other and from Ts65Dn. These models can help to identify the contributions of genes from different regions of the chromosome on this and other aspects of brain development in trisomy.     

Percutaneous coronary laser balloon angioplasty: initial results of a multicenter experience

A multicenter clinical trial was initiated to test the potential safety and short-term efficacy of a percutaneous coronary application of laser balloon angioplasty, which has been shown experimentally to alleviate the common causes (dissection, recoil, thrombus) of suboptimal luminal results of conventional balloon angioplasty. Fifty-five patients, the majority (62%) of whom had relatively high risk lesions, were treated in 10 centers with a laser balloon that was identical in size (3 x 20 mm) to a balloon used for conventional balloon angioplasty performed on the same lesion immediately before laser balloon angioplasty. One or more neodymium:yttrium aluminum garnet (Nd:YAG) (1,060 nm) laser doses of 250 to 450 J were each delivered over a 20 s duration per exposure. Immediately and 1 day after laser balloon angioplasty no significant adverse effects on the arterial lumen were noted in any patient. By computerized image analysis of cineangiograms initial conventional balloon angioplasty failed to achieve a minimal luminal diameter greater than 1.5 mm in 14 patients (25%), including 3 patients with acute closure. However, after subsequent laser balloon angioplasty, minimal luminal diameter exceeded this value in all patients including this subgroup. Overall, minimal luminal diameter increased from 1.74 +/- 0.46 mm after conventional balloon angioplasty to 2.32 +/- 0.31 mm after laser balloon angioplasty (p less than 0.001) with no change found on 1 day and 1 month follow-up angiograms. Thus, laser balloon angioplasty is a safe, effective procedure for improving luminal dimensions after conventional balloon angioplasty.     

Comparison of i.v. and s.c. diamorphine infusions for the treatment of acute pain in children

We have compared the i.v. and s.c. routes of administration for diamorphine infusions in children undergoing abdominal surgery. Subjects received general anaesthesia with extradural block and diamorphine up to 20 micrograms kg-1 h-1 after operation. There were no differences between the groups in diamorphine consumption, pain scores or incidence of side effects. The s.c. route appeared to be as effective and safe as the i.v. route for administration of diamorphine infusions in children undergoing elective surgery.      

The temporal structure of spike trains in the primate basal ganglia: afferent regulation of bursting demonstrated with precentral cerebral cortical ablation

We studied the temporal pattern of discharge of single units in the basal ganglia of awake primates sitting quietly. Bursting was studied with a procedure that identified individual bursts in a spike train, quantifying burst intensity (surprise), bursts per 1000 spikes, spikes per burst and burst length. Autocorrelation techniques were used to assess the dependencies of spike trains on the temporal order of intervals. Striatal units had a greater tendency to burst (79% of units) than pallidal units (50%). The caudate nucleus and putamen had nearly identical burst properties on all measures. In the pallidum, bursting was more prevalent in the external segment and bursts were more intense and more frequent than in the internal segment. The autocorrelation analysis revealed that the temporal structure of the spike train was more dependent on the order of intervals in the striatum than in the pallidum. Bursting units had an increased probability of discharge after each spike and the relative refractory period was shorter in bursting units than units without bursts. Very few units exhibited cyclic discharge properties. Ablations of areas 4 and 6 in the precentral cortex demonstrated that striatal bursting was under afferent control. The putamen, which receives more cortical afferents from areas 4 and 6 than the caudate nucleus, had fewer and less intense bursts after the afferents were lesioned. Burst intensity did not change in the pallidum after the lesion. The findings indicate that bursting properties contribute to discharge variability in the basal ganglia and suggest that information transfer in the striatum may utilize bursts. In contrast, rate coding may be a more important mechanism for units in the pallidum.