Evidence for two electronic components in high-temperature superconductivity from NMR

A new analysis of (63)Cu and (17)O NMR shift data on La(1.85)Sr(0.15)CuO(4) is reported that supports earlier work arguing for a two-component description of La(1.85)Sr(0.15)CuO(4), but conflicts with the widely held view that the cuprates are a one-component system. The data are analyzed in terms of two components A and B with susceptibilities χ(AA), χ(AB)(= χ(BA)) and χ(BB). We find that above T(c), χ(AB) and χ(BB) are independent of temperature and obtain for the first time the temperature dependence of all three susceptibilities above T(c) as well as the complete temperature dependence of χ(AA)+χ(AB) and χ(AB)+χ(BB) below T(c). The form of the results agrees with that recently proposed by Barzykin and Pines.

High sensitivity nuclear magnetic resonance probe for anvil cell pressure experiments

While the highest pressures can be achieved with diamond anvil cells, limited sample size and anvil geometry have hampered their application in nuclear magnetic resonance (NMR) experiments due to weak signal-to-noise. Here we report a new probe design that is based on having the resonant radio frequency coil that encloses the sample within the anvil cell inside the gasket hole. This increases the filling factor tremendously and results in greatly enhanced NMR sensitivity. The setup is described together with room temperature Na and Al NMR experiments.

Four-year results after brachytherapy for diffuse coronary in-stent restenosis: will coronary radiation therapy survive?

BACKGROUND

Prior to the introduction of drug-eluting stents (DES), diffuse coronary in-stent restenosis (ISR) was mainly treated by brachytherapy (BT), with good short-term and mid-term results. However, there exist limited data on the long-term effects of BT that justify its continuous use.

MATERIALS AND METHODS

Two hundred patients with diffuse ISR treated with intravascular BT were retrospectively followed over 4 years. Group A (n=134) was treated with the noncentered (90)Sr/Y BetaCath radiation system, whereas Group B (n=66) was treated with the centered 32P Galileo source wire system. Primary endpoints after 4 years were target lesion restenosis (TLS) and target lesion revascularization (TLR). Secondary endpoints were target vessel revascularization (TVR) and nontarget vessel revascularization (NTVR), as well as major adverse cardiac events (MACE).

RESULTS

Follow-up at 4 years yielded a TLS rate of 37.6% (Group A, 40.8%; Group B, 31.1%; P=.48). TLR was performed in 34.8% of patients (37.5% in Group A vs. 29.5% in Group B; P=.55). Ten percent of patients underwent coronary bypass surgery. Percutaneous coronary intervention was performed more often in Group A (27.5%) than in Group B (19.7%), while TVR was less frequent in Group A (10.0%) than in Group B (18.0%). NTVR was undertaken in 25.0% of Group A patients versus 21.3% of Group B patients, and MACE occurred in 1.7% of Group A patients versus 3.3% of Group B patients. These differences were not statistically significant (P>.05).

CONCLUSIONS

While excellent short-term and mid-term results after coronary BT are widely accepted, a high TLS rate can be observed after 4 years. The potential superiority of DES to BT will depend on the availability of long-term clinical data.

Albuminuria, intermittent hyperfiltration and salt wasting in patients with stroke: a pilot study

OBJECTIVE

To investigate whether different types of stroke influence renal excretion of albumin, major electrolytes and water.

MATERIAL AND METHODS

Timed urine collections were started shortly after admission in 5 patients with haemorrhagic stroke (group A), 5 with ischaemic stroke (group Bx), 6 with presumed ischaemic stroke (groups By/z) and 6 with subarachnoid haemorrhage (group C). Albuminuria was also investigated in four patients undergoing elective abdominal surgery.

RESULTS

Increased levels of albuminuria were observed in all patients in groups A and B, but were found to decline with observation time and appeared to be related to outcome in group B. In group C, albuminuria was detected in 4 out of 6 patients. Elective surgery did not affect albumin excretion. In a setting with high urinary osmolality, high excretion rates for creatinine, urea, sodium, potassium and large diuresis were intermittently observed in groups A, B and C. None of these patients was in steady-state condition.

CONCLUSIONS

Different types of stroke elicit a complex change in renal function which resembles the response to a hypervolaemic and hyperosmolar signal, possibly mediated by a breakdown of renal autoregulation of blood flow in the presence of high vasopressin activity. Acute changes in excretion of albumin might be an indicator of prognosis in stroke. The findings point to the existence of unrecognized pathways between the central nervous system and the kidneys. Further studies on the mechanisms underlying alterations in renal function in stroke and their implication for treatment and outcome are indicated.

Carpal tunnel syndrome--a comprehensive review

PURPOSE

To provide a comprehensive review of the management of carpal tunnel syndrome.

METHODS AND RESULTS

A systematic literature review is provided of the history, anatomy, pathophysiology, epidemiology, diagnostic criteria, investigative surgical techniques, results and complications for carpal tunnel syndrome.

CONCLUSION

Surgery for carpal tunnel syndrome requires meticulous attention to history-taking, investigation, counseling, training and surgical technique if unsatisfactory results and complications are to be avoided.

Improved clinical outcome after intracoronary administration of bone-marrow-derived progenitor cells in acute myocardial infarction: final 1-year results of the REPAIR-AMI trial

AIMS

To investigate the clinical outcome after intracoronary administration of autologous progenitor cells in patients with acute myocardial infarction (AMI).

METHODS AND RESULTS

Using a double-blind, placebo-controlled multicentre trial design, we randomized 204 patients with successfully reperfused AMI to receive intracoronary infusion of bone-marrow-derived progenitor cells (BMCs) or placebo medium into the infarct artery 3-7 days after successful infarct reperfusion therapy. At 12 months, the pre-specified cumulative endpoint of death, myocardial infarction, or necessity for revascularization was significantly reduced in the BMC group compared with placebo (P=0.009). Likewise, the combined endpoint death, recurrence of myocardial infarction, and rehospitalization for heart failure was significantly (P=0.006) reduced in patients receiving intracoronary BMC administration. Intracoronary administration of BMC remained a significant predictor of a favourable clinical outcome by Cox regression analysis, adjusting for classical predictors of poor outcome after AMI.

CONCLUSION

Intracoronary administration of BMCs is associated with a significant reduction of the occurrence of major adverse cardiovascular events after AMI. Large-scale studies are warranted to confirm the effects of BMC administration on mortality and morbidity in patients with AMIs.

Initial Clinical Experience with the Protégé EverFlex™ Long Self-Expanding Nitinol Stent in the Superficial Femoral Artery

AIMS

Clinical results following stent implantation in the superficial femoral artery (SFA) are limited due to restenosis, often caused by stent fractures. Therefore new stent devices are desirable. The present study details our initial experience with the routine use of the novel Protégé EverFlex long self-expanding nitinol stent for treatment of long SFA total occlusions or stenoses.

METHODS AND RESULTS

Between February and March 2006 a total of 15 EverFlex nitinol stents were implanted in 12 patients with either total SFA occlusions (n = 9) or long stenoses (n = 3), mean lesion length 14.9 cm (+/- 10.4 cm). All patients presented with claudication stage Fontaine IIb (Rutherford category 3). Stent lengths were 10 cm (n = 6), 12 cm (n = 1), or 15 cm (n = 8), stent diameters were 6 mm (n = 14) and 7 mm (n = 1). Access was gained either by the crossover (n = 9), antegrade (n = 2), or popliteal approach (n = 1). After predilatation, stent placement and postdilatation were performed with 100% technical success. Clinical and apparative follow-up after 6-8 weeks indicated the absence of restenosis or reocclusion in all cases.

CONCLUSION

The novel long self-expanding EverFlex nitinol stent (10 cm/12 cm/15 cm in length) exhibits excellent technical handling characteristics with good short-term clinical results. Mid-term and long-term clinical results as well as potential stent fractures need to be further examined.

Sperm Donation: Implications of Canada’s Assisted Human Reproduction Act 2004 for Recipients, Donors, Health Professionals, and Institutions

BACKGROUND

On April 22, 2004, the Assisted Human Reproduction Act came into force, prohibiting the purchase of sperm or eggs from donors in Canada. In response to the concerns of medical professionals and some consumers that prohibiting payment would lead to a decline in the number of gamete donors, Health Canada commissioned research on altruistic donor recruitment and recruitment strategies.

METHODS

Twenty-two studies of sperm donors were located and their findings reviewed. The studies spanned 23 years (1980-2003), were undertaken in a range of countries, and were chosen on the merit of their relevance to the development of recruitment strategies within a policy of altruistic sperm donation. Observations were derived from assessing and comparing the purposes, findings, and implications of the 22 studies.

RESULTS

Payment for providing sperm was made in all but three studies, although participants in 15 studies indicated clearly that their motivations were primarily altruistic. Observations indicate that men who are more willing to be identified to offspring in the future share demographic characteristics, such as age and parental status, with those who are prepared to donate altruistically. These characteristics appear to be a factor in motivation to donate altruistically.

CONCLUSION

The studies show that there are men who are prepared to donate sperm without financial payment. The findings suggest that a change is required in the culture of sperm donation, specifically the adoption of a new approach to donor recruitment.

Thin-foil magnetic force system for high-numerical-aperture microscopy

Forces play a key role in a wide range of biological phenomena from single-protein conformational dynamics to transcription and cell division, to name a few. The majority of existing microbiological force application methods can be divided into two categories: those that can apply relatively high forces through the use of a physical connection to a probe and those that apply smaller forces with a detached probe. Existing magnetic manipulators utilizing high fields and high field gradients have been able to reduce this gap in maximum applicable force, but the size of such devices has limited their use in applications where high force and high-numerical-aperture (NA) microscopy must be combined. We have developed a magnetic manipulation system that is capable of applying forces in excess of 700 pN on a 1 mum paramagnetic particle and 13 nN on a 4.5 mum paramagnetic particle, forces over the full 4pi sr, and a bandwidth in excess of 3 kHz while remaining compatible with a commercially available high-NA microscope objective. Our system design separates the pole tips from the flux coils so that the magnetic-field geometry at the sample is determined by removable thin-foil pole plates, allowing easy change from experiment to experiment. In addition, we have combined the magnetic manipulator with a feedback-enhanced, high-resolution (2.4 nm), high-bandwidth (10 kHz), long-range (100 mum xyz range) laser tracking system. We demonstrate the usefulness of this system in a study of the role of forces in higher-order chromosome structure and function.

[Long-term fate of left atrial thrombi and incidence of cerebral embolism under continuous anticoagulation therapy]

PURPOSE

Patients (pts.) with atrial fibrillation (AF) and atrial thrombi are known to have an increased risk for cerebral embolism. However, little is known about the clinical course of atrial thrombi and the incidence of cerebral embolism in those patients during anticoagulation therapy. The high sensitivity of MR imaging (MRI) including diffusion-weighted imaging (DWI) suggests that this technique could provide an improved estimate of cerebral embolism associated with the presence of left atrial thrombi. The aims of this prospective study were to evaluate 1) the prevalence of clinically silent and apparent cerebral embolism in pts. with newly diagnosed AF and atrial thrombi using MRI/DWI, 2) the long-term fate of atrial thrombi under continues anticoagulation therapy and 3) the incidence of cerebral embolism during a follow-up period of 12 months with continuous anticoagulation therapy.

MATERIALS AND METHODS

The study group consisted of 32 pts. with 1) newly diagnosed AF and evidence of left atrial (LA) thrombi detected by TEE and 2) a new start of anticoagulation therapy [International Normalized Ratio (INR) 2.0 - 3.0]. 19 pts. with 1) newly diagnosed AF and no evidence of atrial thrombi and 2) an equivalent anticoagulation regimen served as the control group. In both groups a) MRI/DWI studies of the brain (weeks 0, 4, 8, 12, 20, 28, 36, 44, and 52), b) transesophageal echocardiographic studies (TEE) for assessment of LA-Thrombi (weeks 0 and 52) and c) clinical neurological assessments (weeks 0, 20 and 52) were performed.

RESULTS

In the study group (AF and LA-Thrombi) 11 out of 32 pts. (34 %) displayed signs of acute (n = 8) or chronic (n = 3) cerebral embolism in the initial MRI studies. In 4 out of 32 pts. (13 %), MRI/DWI depicted new or additional cerebral emboli (n = 12) during the follow-up period despite continuous anticoagulation therapy. 2 (n = 2/4; 50 %) of these patients had clinically apparent neurological deficits. In the control group 1 out of 19 pts. (5 %) showed evidence of chronic cerebral embolism as assessed by MRI/DWI at the beginning of the study (week 0). No embolic cerebral lesions were detected during the 12-month follow-up. Within 12 months only 63 % (n = 20/32) of LA thrombi in the study group resolved completely under anticoagulation.

CONCLUSION

1. The incidence of clinically inapparent cerebral emboli in pts. with newly diagnosed AF and atrial thrombi is much higher than the incidence of clinically apparent emboli and has been underestimated in the past. 2. New cerebral embolism may occur even with continued effective anticoagulation therapy in 13 % of pts. 3. Only 63 % of atrial thrombi resolve completely within 12 months under anticoagulation therapy.

One-Year Clinical Outcomes After Complete Arterial Coronary Revascularization

BACKGROUND

Conventional coronary bypass surgery applies single internal mammary arteries and saphenous vein graft conduits for revascularization of occluded coronary arteries. While the use of saphenous vein grafts is limited by early graft occlusion, little data exist on clinical experiences with complete arterial revascularization.

PATIENTS AND METHOD

From January 2003 to July 2004, 390 patients were transferred from Red Cross Hospital Cardiology Center to the Rotenburg Cardiovascular Center for coronary bypass operation. From these patients, 200 were selected for complete arterial revascularization. Mean age of the patients was 66.7+/- 8.0 years; 80.5% were male; 68.5% had triple-vessel disease, 31% had two-vessel disease, and 0.5% had single-vessel disease; 32% were diabetic; and 6.5% had a previous bypass operation. Left ventricular ejection fraction was >50% in 85.5% and 30-50% in 14.5%. Double internal mammary artery grafts were used in 98% and single internal mammary artery grafts in 2%. In 51%, the right internal mammary artery was connected with the left internal mammary artery as a T-graft and in 17%, it was used as a free aortocoronary graft. Radial artery grafts were used in 4%. The average number of anastomoses per patient was 3.4.

RESULTS

During the primary in-hospital stay, 1.5% of the patients had to undergo reoperation, 3.5% had myocardial infarctions, 3.5% had wound healing complications, 1.0% experienced an ischemic stroke, and 1 patient died following an acute myocardial infarction. At 12 months, 1.0% underwent percutaneous reinterventions, 0.5% had to be reoperated, 0.5% had a myocardial infarction, and 1.0% died. The actuarial survival rate at 12 months was 99%.

CONCLUSION

When both the internal mammary arteries are used as the preferred surgical strategy, complete arterial revascularization can be performed with excellent clinical results over 12 months.

Percutaneous Saphenous Vein Graft Interventions with and without Distal Filter Wire Protection

BACKGROUND

Embolic protection during SVG interventions using distal balloon occlusion and aspiration has shown to reduce periprocedural complications compared to unprotected SVG interventions. A similar effect is expected from filter wires.

PATIENTS AND METHODS

A total of 174 SVG interventions carried out with (group A; n=87) or without distal filter wire protection (group B; n=87) were retrospectively matched for the location of distal graft anastomosis and analyzed for baseline and procedural characteristics, for TIMI flow grade before and after PCI, for the post-procedural CK elevation, and for major adverse cardiac events at 30 days and 6 months (primary end point). Location of distal graft anastomosis was the left anterior descending artery in 19.6%, the left diagonal branch in 6.9%, the left marginal branch in 17.2%, the left posterolateral branch in 24.2%, the mid-segment of the right coronary artery in 28.7%, and the posterior descending artery in 3.4%.

RESULTS

Baseline clinical demographics showed no relevant differences between both the groups. Mean age of vein grafts was 11.7+/- 4.3 years in group A versus 10.6+/- 4.9 years in group B (P=0.15). The number of stents per lesion was 1.4+/- 0.8 in group A versus 1.0+/- 0.8 in group B (P<0.01). The total length of stents was 32.2+/- 16.2 mm in group A versus 20.9+/-12.1 mm in group B (P<0.01). TIMI flow grade pre was 2.5+/-0.8 in group A versus 2.7+/- 0.6 in group B (P<0.05). TIMI flow grade post was 2.9+/- 0.3 versus 2.9+/- 0.2. Improvement of TIMI flow grade after SVG intervention was 0.4+/- 0.7 in group A versus 0.2+/- 0.6 in group B (P<0.05). Post-procedural CK-MB elevations were observed in 17 patients of group A versus 14 patients of group B (P=0.18). At 30 days, there were no myocardial infarctions (MIs) and no deaths in either group. One patient of group A had to be reoperated and four patients of group A underwent repeat PCI (4.6%) versus one patient of group B (1.2%). At 6 months, there were again no MIs and no deaths in either group. Target lesion revascularization rate was 17.3% in group A versus 11.5% in group B (P <0.02).

CONCLUSION

When distal filter wire protection is used in high risk SVG lesions, the clinical outcome of percutaneous interventions may be equal to low risk SVG lesions without filter wire protection.

One-year results of a durable polymer everolimus-eluting stent in de novo coronary narrowings (The SPIRIT FIRST Trial)

AIM

Short-term results of durable polymer everolimus-eluting stents have shown significant improvements in clinical and angiographic outcomes. This report presents the 1-year clinical and angiographic data from the SPIRIT FIRST Trial.

METHODS AND RESULTS

This first-in-man single blind multi-centre randomized controlled trial assessed the safety and efficacy of everolimus and a durable polymer on a cobalt chromium stent in patients with de novo native coronary artery lesions. Of the 60 patients enrolled, a total of 56 patients (27 everolimus arm and 29 bare stent arm) were qualified to per-treatment analyses at 1 year. Quantitative angiographic and intravascular ultrasound (IVUS) analyses were performed. Angiographic late loss, IVUS neointimal volume obstruction and major adverse cardiac events (MACE) at 1 year were assessed as the study endpoints. At 1 year, the in-stent late loss and diameter stenosis of patients were 0.24 mm and 18% in the everolimus arm (n=20), as compared with 0.84 mm and 37% in the bare stent arm (n=25, p < 0.001). Significantly less neointimal hyperplasia was observed in the everolimus arm compared to the bare stent arm (neointimal volume, 13+/-9 mm3 vs. 37+/-17 mm3, p < 0.001; volume obstruction, 10+/-7% vs. 28+/-12%, p < 0.001). The overall MACE rate was 15.4% in the everolimus arm and 21.4% in the bare stent arm.

CONCLUSION

The safety and efficacy of everolimus-eluting stent with a durable polymer observed at 6 months was sustained at 1 year.

Comparison of a centered 32P source wire system with a noncentered 90Sr/Y brachytherapy system for intracoronary β-radiation following PCI of diffuse in-stent restenosis

BACKGROUND

We investigated the potential impact of differences in effective radiation dose between the centered Guidant 32P source wire system and the noncentered Novoste 90Sr/Y BetaCath system on clinical and angiographic outcomes of intracoronary brachytherapy for the prevention of in-stent restenosis.

METHODS

From 10/00 to 05/04, a total of 400 patients underwent percutaneous coronary intervention (PCI) with brachytherapy for diffuse in-stent restenosis at our institution. Following balloon dilatation, patient Group A (n=200) was treated with the centered 32P Galileo source wire system, patient Group B (n=200) was treated with the noncentered 90Sr/Y BetaCath radiation system. In Group A, the prescribed dose of 20 Gy was applied in 1-mm depth of the vessel wall. In Group B, the prescribed dose of 18.4 Gy was applied for visual reference vessel sizes >2.7 and <3.35 mm, 23 Gy for >3.36 and <4.00 mm, and 25.3 Gy for >4.00 mm, each calculated at a distance of 2 mm from the center line of the radiation source. Patients received aspirin and clopidogrel over 12 months. Primary endpoint was target lesion revascularization (TLR) at 6 months. Secondary endpoints were the binary restenosis rate and major adverse cardiac event (MACE) at 30 days and 6 months.

RESULTS

At 30 days, one patient of each group underwent PCI at a nontarget lesion (0.5%). At 6 months, MACEs were equally distributed in both groups. Target lesion revascularization at 6 months was 5.9% in Group A and 9.2% in Group B (P=.08). Binary angiographic restenosis rate at 6 months was 5.5% in Group A and 11.2% in Group B (P=.014).

CONCLUSION

Intracoronary beta-radiation using the centered 32P source wire system yielded a significant reduction of recurrence rate compared to the noncentered 90S/Y BetaCath system after PCI of diffuse in-stent restenosis. There was a nonsignificant trend toward reduction of TLR among patients treated with the centered 32P source wire system.