Electrochemically fabricated zero-valent iron, iron-nickel, and iron-palladium nanowires for environmental remediation applications

Monodisperse crystalline zero-valent iron, iron-nickel, iron-palladium nanowires were synthesised using template-directed electrodeposition methods. Prior to nanowire fabrication, alumina nanotemplates with controlled pore structure (e.g. pore diameter and porosity) were fabricated by anodising high purity aluminium foil in sulphuric acid. After fabrication of alumina nanotemplates, iron, iron-nickel and iron-palladium nanowires were electrodeposited within the pore structure. The dimensions of nanowires including diameter and length were precisely controlled by pore diameter of anodised alumina and deposition rate and time. The composition, crystal structure and orientation were controlled by adjusting electrodeposition parameters including applied current density and solution compositions.

Randomized clinical trial of laparoscopic Nissen fundoplication compared with proton-pump inhibitors for treatment of chronic gastro-oesophageal reflux

BACKGROUND

Both laparoscopic Nissen fundoplication (LNF) and proton-pump inhibitor (PPI) therapy are established in the treatment of gastro-oesophageal reflux disease (GORD). The aim of this study was to compare these two treatments in a randomized clinical trial.

METHODS

Between July 1997 and August 2001, 340 patients with a history of GORD for at least 6 months were investigated by endoscopy, 24-h pH monitoring and manometry. Of these, 217 were randomized, 109 to LNF and 108 to PPI therapy. The two groups were well matched for age, sex, weight and severity of reflux. Twenty-four-hour pH monitoring and manometry were performed 3 months after treatment, and quality of life was assessed in both groups using the Psychological General Well-being Index and the Gastrointestinal Symptom Rating Scale at 3 and 12 months after treatment.

RESULTS

At 3 months there was an improvement in lower oesophageal sphincter pressure from 6.3 to 17.2 mmHg in the LNF group but no change in the PPI group (8.1 and 7.9 mmHg before and after treatment respectively) (P < 0.001). The mean DeMeester acid exposure score improved from 42.7 to 8.6 (P < 0.001) in the LNF group and from 36.9 to 17.7 in the PPI group (P < 0.001). The mean gastrointestinal symptom and general well-being scores improved from 31.7 and 95.4 respectively before treatment to 37.0 and 106.2 at 12 months after LNF, compared with changes from 34.3 and 98.5 to 35.0 and 100.4 respectively in the PPI group. The differences in both of these scores were significant between the two groups at 12 months (P = 0.003).

CONCLUSION

LNF leads to significantly less acid exposure of the lower oesophagus at 3 months and significantly greater improvements in both gastrointestinal and general well-being after 12 months compared with PPI treatment.

Utility of an ultrafast magnetic resonance imaging protocol in recent and semi-recent strokes

OBJECTIVE

To evaluate the technical feasibility of an integrated ultrafast head magnetic resonance (MR) protocol using a sensitivity encoding (SENSE) technique for depicting parenchymal ischaemia and vascular compromise in patients with suspected recent stroke.

METHODS

23 patients were evaluated with the ultrafast MR protocol using T2, T1, fluid attenuated inversion recovery (FLAIR), 3D time of flight magnetic resonance angiography (MRA), and diffusion weighted imaging (DWI) sequences. These were compared with routine conventional MR sequences.

RESULTS

One patient could not tolerate conventional imaging, although imaging using the three minute head SENSE protocol was diagnostic. Both conventional and ultrafast protocols were of similar diagnostic yield in the remaining patients. There were no significant differences in clinical diagnostic quality for the T1, T2, FLAIR, and DWI sequences. One MRA examination was of better quality when SENSE was used, owing to reduced motion artefacts and shorter imaging time.

CONCLUSIONS

It is possible to undertake a comprehensive MR examination in stroke patients in approximately three to five minutes. Ultrafast imaging may become a useful triage tool before thrombolytic therapy. It may be of particular benefit in patients unable to tolerate longer sequences. Further work is necessary to confirm these findings in hyperacute stroke.

Laparoscopic resection of gastric gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are neoplasms with low malignant potential. They occur most commonly in the stomach, where they are amenable to laparoscopic resection.

METHODS

A case note review of all patients undergoing laparoscopic resection of a presumed gastric GIST at the Norfolk and Norwich University Hospital, United Kingdom, was conducted.

RESULTS

Since September 1995, 30 patients have undergone this procedure. The patients had a mean age of 64.2 years (range, 31-87 years) and a mean weight of 74.1 kg (range, 44-104 kg). A presumptive diagnosis of GIST was made in all the cases based on the endoscopic and radiologic appearance of the lesion. Laparoscopic resection was completed successfully in 23 patients with a mean operating time of 73.8 min (range, 26-160 min). Seven procedures were converted to open surgery: three because the tumor was deemed too large for laparoscopic resection, two because the tumor could not be identified, one because of dense peritoneal adhesions, and one because of bleeding. The mean estimated blood loss was 196 ml (range, 0-1,000 ml), and the mean hospital stay was 5 days (ranges, 1-11 days). Pathologic analysis of the resected specimens showed 22 GISTs, 3 inflammatory fibroids, 2 submucosal lipomas, 1 submucosal varix, and 1 nest of heterotopic pancreatic tissue. D: uring a median follow-up period of 18 months (range, 2-101 months) there have been two cases of recurrence. In both cases, the tumor was catagorized as high risk for aggressive behavior after primary resection.

CONCLUSION

Stapled laparoscopic resection is a safe and effective treatment option for nonmetastatic primary gastric GIST.

EEG changes with vagus nerve stimulation

Vagus nerve stimulation (VNS) has been shown to induce EEG changes in animals, but human studies have not shown any significant acute EEG changes. This study is to determine the long-term effect of VNS on EEG. Twenty-one patients aged 4 to 31 years (mean: 14.1 +/- 7.0 years) were studied for a mean duration of 16.8 months with serial EEGs performed at baseline and at 3 months, 6 months, and 12 months after receiving a VNS implant. Five patients who showed active spikes/spike and wave activity on baseline EEGs were found to have synchronization of epileptiform activity, progressive increase in duration of spike-free intervals (P < 0.05), and progressive decrease in duration and frequency of spikes/spike and wave activity (P < 0.01) with time. The remaining 16 patients with less active baseline EEGs did not show obvious synchronization or clustering of spikes but also showed a statistically significant progressive decrease in the number of spikes on EEG with time (P < 0.004 at 3 months, P < 0.008 at 6 months, and P < 0.004 at 1 year). Vagus nerve stimulation induces progressive EEG changes in the form of clustering of epileptiform activity followed by progressively increased periods of spike-free intervals. This may reflect the mechanism of action of VNS in achieving seizure control: alternating synchronization and desynchronization of EEG, with the latter being progressively the dominant feature.

Human vagus nerve electrophysiology: a guide to vagus nerve stimulation parameters

The authors studied human vagus nerve electrophysiology intraoperatively on 21 patients (age range: 4 to 31 years) during implantation of a vagus nerve stimulator for seizure control. The study was performed with direct electrical stimulation of the vagus nerve with various stimulation parameters resembling those employed by the Cyberonics NeuroCybernetic Prosthesis System (Houston, TX), which is used clinically for vagus nerve stimulation for treatment of seizures. Recordings were made directly from the rostral end of the vagus nerve. The response of the vagus nerve to various stimulus parameters in patients of different ages was studied. Based on the vagus nerve characteristics, age-related adjustments for stimulus parameters were recommended.

In vitro and in vivo studies of AT-1362, a newly synthesized and orally active inhibitor of thrombin

AT-1362 was found to be a potent, selective, and competitive inhibitor of thrombin, with a Ki value of 6.7 nM. In a rat model of venous thrombosis induced by partial stasis and endothelial disruption, the ID(50) values (a dose required to obtain 50% inhibition of thrombus formation over each vehicle group) of AT-1362 and argatroban were 0.03 mg/kg i.v. plus 0.5 microg/kg/minute and 0. 13 mg/kg i.v. plus 8.7 microg/kg/minute, respectively, and the antithrombotic effect of AT-1362 without prolongation of bleeding time lasted for 2 hours and disappeared 4 hours after oral administration of 30 mg/kg. In the rat tail transection model, the BT(2) values (a dose causing two-fold prolongation of the bleeding time over each vehicle group) of AT-1362 and argatroban were 0.56 mg/kg i.v. plus 9.3 microg/kg/minute and 1.1 mg/kg i.v. plus 73.3 microg/kg/minute, respectively. The reduction of thrombus formation and the prolongation of bleeding time were correlated with an ex vivo activated partial thromboplastin time (APTT) for both drugs. AT-1362 at 0.3 mg/kg i.v. plus 5 microg/kg/minute and argatroban at 0.6 mg/kg i.v. plus 40 microg/kg/minute significantly (p<0.05 and p<0.01, respectively) improved the vessel patency in a FeCl(2)-induced carotid artery thrombosis model in rats. These results suggest that AT-1362 may be a potent antithrombotic agent for the treatment of thrombotic diseases.

TRAF-3 interacts with p62 nucleoporin, a component of the nuclear pore central plug that binds classical NLS-containing import complexes

The TRAF-3 gene encodes a number of splice-variant isoforms that function as adapter molecules in NF-kappaB signaling, in part by associating with the cytoplasmic tails of CD40 or other TNF-receptor (TNF-R) family members. To identify downstream molecules in TRAF-3 signaling, a yeast two-hybrid library was screened with a full-length TRAF-3 construct. Nine independent TRAF-3 interacting clones encoded fragments of p62 Nucleoporin (p62), a 522 amino acid (aa) component of the nuclear pore central plug, that is known to bind karyopherin-beta/classical-NLS import factor complexes. The interaction of p62 with TRAF-3 was specific, since p62 failed to interact with TRAF-2, -4, -5, or -6. Deletional analysis in yeast revealed that the p62:TRAF-3 interaction is mediated by a p62 carboxy (C)-terminal coiled-coil domain and TRAF-3's fifth zinc (Zn) finger and coiled-coil domain. In human 293 T cells, recombinant TRAF-3 or p62 specifically co-immunoprecipitates the other species. In addition, endogenous p62 co-precipitates over-expressed TRAF-3. The functional effects of over-expressing a TRAF-3 binding fragment, p62(aa 336-522) were studied on NF-kappaB-dependent, or control STAT1-dependent reporter activity in 293 T cells, either resting or after stimulation by CD40 or IFN-gamma, respectively. Over-expression of p62(aa 336-522) induces NF-kappaB activation in resting cells and augments CD40-induced NF-kappaB activation, but has no effect on control STAT1 reporter activity, either at baseline or after IFN-gamma induction. The finding that TRAF-3 binds p62, suggests that TRAF-3 may serve as an adapter molecule at the nuclear membrane, in addition to its known adapter function at the plasma membrane.

Vigabatrin in the treatment of infantile spasms

Infantile spasms (IS) have been conventionally treated with adrenocorticotropic hormone (ACTH), which is often associated with significant side effects. This study assessed the efficacy of vigabatrin (VGB) as an alternative in the treatment of IS and compared the efficacy of VGB in symptomatic vs cryptogenic patients. The study retrospectively reviewed 25 infants with IS (19 symptomatic, six cryptogenic) who were treated with VGB. Of the symptomatic group, 13 (68.4%) of 19 had clinical improvement, and 15 (78.9%) had electroencephalographic improvement. Three (50%) of six in the cryptogenic group had clinical improvement, and two (33%) had electroencephalographic improvement. Overall, three patients demonstrated clinical spasm control but electroencephalographic deterioration or persistence of hypsarrhythmia coupled with further cognitive decline. Four of the six partial clinical responders had deterioration of spasms with additional VGB dosage increases. VGB is comparable with ACTH in effectiveness for treatment of symptomatic IS. Higher doses of VGB may sometimes cause deterioration rather than further improvement, and therefore an optimum dosage of VGB needs to be titrated for every patient. Persistent electroencephalographic abnormalities and even electroencephalographic deterioration despite clinical control have been observed with VGB treatment; electroencephalographic monitoring during VGB treatment is recommended.

Localization of focal cortical lesions influences age of onset of infantile spasms

PURPOSE

To determine whether the localization of focal cerebral lesions affects age of onset of infantile spasms (IS).

METHODS

We reviewed 216 cases of IS and identified patients with focal cerebral lesions confined to frontal, centrotemporoparietal, or occipital regions. The age of onset of spasms in each of the three groups was analyzed.

RESULTS

Ninety-three patients were found to have focal cerebral lesions confined to one of the three regions previously described. The mean age of onset of IS was 3.36 +/- 1.71 months in patients with occipital lesions, 6.26 +/- 2.68 months in centrotemporoparietal lesions, and 9.83 +/- 2.56 in frontal lesions.

CONCLUSIONS

Occipital lesions are found to be associated with earliest onset of spasms, whereas frontal lesions are rare and associated with latest spasms onset. The age distribution pattern of spasms onset according to localization of cortical lesion is in close correlation with that of normal sequence of brain maturation. This supports the hypothesis that cerebral lesions located in critical areas of brain maturation have a role in the genesis of infantile spasms.

Juvenile Huntington disease: CT and MR features

PURPOSE

To describe the clinical and radiologic manifestations of juvenile Huntington disease and to determine whether adult imaging criteria for Huntington disease are helpful for pediatric patients.

METHODS

Six patients (3 to 18 years of age; mean age, 9.8 +/- 5.6 years; 3 female, 3 male) with juvenile Huntington disease were studied with CT (n = 6) and/or MR (n = 3). CT and MR studies were evaluated for frontal horn distance/intercaudate distance and bicaudate ratios, which were compared with those of 24 age-matched healthy children and 12 age-matched patients with Leigh (n = 9) or Wilson (n = 3) disease.

RESULTS

Atrophy of the caudate nuclei was identified in all Huntington patients. The frontal horn distance/intercaudate distance (1.64 +/- 0.39) and bicaudate (0.205 +/- 0.060) ratios of the patients with juvenile Huntington disease were found to be significantly different from those of healthy children and that of those patients with Leigh/Wilson disease. The 3 patients with Huntington disease who underwent MR evaluation were noted to have increased proton density- and T2-weighted signal in the caudate nuclei and putamina.

CONCLUSION

As in adult patients, the use of frontal horn distance/intercaudate distance and bicaudate ratios are helpful for the diagnosis of Huntington disease in pediatric patients. On MR, increased proton density- and T2-weighted signal in the atrophic caudate nuclei and putamina are additional features of juvenile Huntington disease.

Infantile spasms: outcome and prognostic factors of cryptogenic and symptomatic groups

We reviewed the outcome (developmental, neurologic, and seizure) and prognostic factors of 57 cases of infantile spasms (17 cryptogenic, 40 symptomatic). The mean developmental score of the cryptogenic group (71.2 +/- 24.2) was significantly higher than that of the symptomatic group (48.4 +/- 24.5), as assessed by the Griffith Mental Developmental Scale. A resultant neurologic deficit was present in 23.5% of the cryptogenic group and 75.0% of the symptomatic group. Coexistence of other forms of seizures was observed in 35.3% of the cryptogenic group and 57.5% of the symptomatic group. Outcome was affected by the coexistence of other seizures, presence of neurologic deficit, time lag in initiation of treatment (cognitive outcome only), poor response to ACTH treatment, and persistent EEG abnormality. Character of spasms and time lag in initiation of treatment (seizure outcome only) did not have any significant effect on outcome.

Mitochondrial encephalomyopathy, lactic acidosis, stroke-like episodes (MELAS): clinical, radiological, pathological, and genetic observations

We reviewed 10 patients (5 males, 5 females) with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. The age of symptom onset ranged from 3 months to 12 years. All had lactic acidosis, multiple stroke-like events with secondary neurological deficits, radiological changes of progressive brain infarction, and muscle biopsy showing ragged-red fibers. In patients with earlier onset of symptoms (< 2 yr), involvement tended to be more diffuse, with failure to thrive and early onset of delayed development. Patients whose symptoms appeared later tended to have focal neurological deficits with migraine-like headache, and a rate of cognitive regression reflecting the rapidity of disease progression. Radiological changes included multiple areas of infarction with initial predilection for parietal occipital areas, progressing to generalized atrophy. Pathological findings in muscle biopsies included type 1 fiber predominance, ragged-red fibers, increased intermyofibrillar lipid deposition, and abnormal mitochondria. Four patients showed mitochondrial DNA tRNA mutation at position 3,243. No difference was noted in clinical, radiological, or pathological findings in patients with and without this mutation, suggesting that multiple sites of point mutation may give rise to mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes.