A SERS-Active System Based on Silver Nanoparticles Tethered to a Deposited Silver Film

A series of SERS-active nanostructures were produced by exposing a freshly deposited silver film (fabricated to be as free from roughness as practicable) to a solution containing a mixture of 1-decanethiol (m) and 1,9-nonanedithiol (d) of varying concentrations of m to d, then allowing colloidal silver nanoparticles to interact with the surface. Silver nanoparticles were found to bind exclusively to films which were prepared from solutions with a nonzero concentration of the dithiol implying that the nanoparticles were tethered to the silver surface by the dithiol with one of the thiolate groups bound to the nanoparticle and the other to the silver film. Intense SERS spectra were observed even from samples in which the m/d concentration ratio was so large that the adsorbed molecules in the vicinity of only approximately 8 +/- 3 nanoparticles were illuminated by the diffraction-limited focused laser beam. At such high dilution, the molecules (numbering at most approximately 330) residing in the SERS "hot spots" associated with the approximately 8 nanoparticles consisted primarily of m (although, of course, for each nanoparticle, at least one molecule in the hot spot had to be d to serve as the linker). This was corroborated by the SERS spectra. An analysis is presented, which accounts for the fact that as the concentration ratio of m/d increases, the SERS intensity associated with bands belonging to m first increases to a maximum then decreases. The nanoparticle-metal film system presented here is a simple embodiment of a more general range of SERS-active sensing platforms in which a molecular tether is used to create a SERS hot spot that (although nanosized) is large enough to accommodate analyte molecules that cannot themselves function as linkers, which are subsequently detected by SERS at the few-molecule level.

Enterococcal prosthetic valve infective endocarditis: report of 45 episodes from the International Collaboration on Endocarditis-merged database

Enterococcal prosthetic valve infective endocarditis (PVE) is an incompletely understood disease. In the present study, patients with enterococcal PVE were compared to patients with enterococcal native valve endocarditis (NVE) and other types of PVE to determine differences in basic clinical characteristics and outcomes using a large multicenter, international database of patients with definite endocarditis. Forty-five of 159 (29%) cases of definite enterococcal endocarditis were PVE. Patients with enterococcal PVE were demographically similar to patients with enterococcal NVE but had more intracardiac abscesses (20% vs. 6%; p=0.009), fewer valve vegetations (51% vs. 79%; p<0.001), and fewer cases of new valvular regurgitation (12% vs. 45%; p=0.01). Patients with either enterococcal PVE or NVE were elderly (median age, 73 vs. 69; p=0.06). Rates of in-hospital mortality, surgical intervention, heart failure, peripheral embolization, and stroke were similar in both groups. Patients with enterococcal PVE were also demographically similar to patients with other types of PVE, but mortality may be lower (14% vs. 26%; p=0.08). Notably, 93% of patients with enterococcal PVE came from European centers, as compared with only 79% of patients with enterococcal NVE (p=0.03). Thus, patients with enterococcal PVE have higher rates of myocardial abscess formation and lower rates of new regurgitation compared to patients with enterococcal NVE, but there are no differences between the groups with regard to surgical or mortality rates. In contrast, though patients with enterococcal PVE and patients with other types of PVE share similar characteristics, mortality is higher in the latter group. Importantly, the prevalence of enterococcal PVE was higher in the European centers in this study.

The Isthmus of Panama: a major physical barrier to gene flow in a highly mobile pantropical seabird

To further test the hypothesis that the Isthmus of Panama is a major barrier to gene flow in pantropical seabirds, we applied phylogeographic methods to mitochondrial control sequence variation in masked booby (Sula dactylatra) populations on either side of the Isthmus of Panama and the southern tip of Africa. In accord with Steeves et al. (2003), we found that all Caribbean masked boobies with the 'secondary contact' cytochrome b haplotype (m-B) shared a control region haplotype (Sd_100), which grouped with Indian-Pacific haplotypes and not Caribbean-Atlantic haplotypes. In addition, Sd_100 was more closely related to control region haplotypes in the Indian Ocean than in the Pacific. We also found that the 'secondary contact' birds diverged more recently from extant populations in the Indian Ocean than in the Pacific. Thus, it appears that these masked boobies did not breach the Isthmus of Panama. Rather, birds likely dispersed around the southern tip of Africa during favourable oceanographic conditions in the Pleistocene.

Enterococcal endocarditis: 107 cases from the international collaboration on endocarditis merged database

PURPOSE

To describe clinical features and outcomes of enterococcal left-sided native valve endocarditis and to compare it to endocarditis caused by other pathogens.

SUBJECTS AND METHODS

Patients in the International Collaboration on Endocarditis-Merged Database were included if they had left-sided native valve endocarditis. Demographic characteristics, clinical features, and outcomes were analyzed. Multivariable analysis evaluated enterococcus as a predictor of mortality.

RESULTS

Of 1285 patients with left-sided native valve endocarditis, 107 had enterococcal endocarditis. Enterococcal endocarditis was most frequently seen in elderly men, frequently involved the aortic valve, tended to produce heart failure rather than embolic events, and had relatively low short-term mortality. Compared to patients with non-enterococcal endocarditis, patients with enterococcal endocarditis had similar rates of nosocomial acquisition, heart failure, embolization, surgery, and mortality. Compared to patients with streptococcal endocarditis, patients with enterococcal endocarditis were more likely to be nosocomially acquired (9 of 59 [15%] vs 2 of 400 [1%]; P <.0001) and have heart failure (49 of 107 [46%] vs 234 of 666 [35%]; P = 0.03). Compared to patients with S. aureus endocarditis, patients with enterococcal endocarditis were less likely to embolize (28 of 107 [26%] vs 155 of 314 [49%]; P <.0001) and less likely to die (12 of 107 [11%] vs 83 of 313 [27%]; P = 0.001). Multivariable analysis of all patients with left-sided native valve endocarditis showed that enterococcal endocarditis was associated with lower mortality (odds ratio [OR] 0.49; 95% confidence interval [CI] 0.24 to 0.97).

CONCLUSIONS

Enterococcal native valve endocarditis has a distinctive clinical picture with a good prognosis.

Risk factors for infective endocarditis in patients with enterococcal bacteremia: a case-control study

BACKGROUND

Based on previous studies, enterococcal infective endocarditis (IE) is considered a unimicrobial, community-acquired disease of older Caucasian men.

PATIENTS AND METHODS

We evaluated the relationship between enterococcal bacteremia and IE by comparing clinical and demographic characteristics of all cases of enterococcal IE within an 8-year period (n = 41) with controls randomly chosen from patients with enterococcal bacteremia without IE.

RESULTS

By univariate and multivariable analyses, the presence of a prosthetic valve (PV) and infection with Enterococcus faecalis were significantly associated with IE, while age, gender, race, polymicrobial infection and community-acquired infection were not. Almost an equal number of women and men had enterococcal IE. Cases of enterococcal IE were commonly nosocomial (39%) and polymicrobial (17%).

CONCLUSIONS

Enterococcal endocarditis can no longer be considered exclusively a unimicrobial, community-acquired disease of Caucasian men. Instead, our data suggest that the presence of a PV and infection by E. faecalis are associated with an increased risk for IE.

Stroke location, characterization, severity, and outcome in mitral vs aortic valve endocarditis

OBJECTIVE

To characterize the incidence and clinical features of patients with infective endocarditis (IE) and stroke.

METHODS

The authors reviewed the records of 707 patients diagnosed with definite or possible IE between January 1984 and November 1999. Stroke was confirmed by application of strict definitions and classified by type, pathophysiology, vascular territory, and severity. The authors determined mortality rates for the initial hospitalization and 12 months after admission.

RESULTS

Strokes occurred in 68 (9.6%) of 707 patients with IE, 38 (17%) of 218 patients with mitral valve endocarditis (MVE), 14 (9%) of 149 patients with aortic valve endocarditis (AVE), and 16 (5%) of 340 patients with other forms of IE (OR for MVE vs AVE = 2.0, 95% CI 1.1 to 3.9). Among the patients with MVE or AVE and stroke, there were no significant relationships between site of vegetation and length of hospitalization, stroke severity, mortality during the initial hospitalization, or 12-month mortality. Fifty-two percent of patients with stroke and IE died within 1 year of admission.

CONCLUSIONS

The overall incidence of stroke in patients with IE (9.6%) is lower than previous reports (21 to 39%). Patients with MVE had a greater risk of stroke than patients with AVE. Fifty-two percent of patients died within 1 year of admission for IE.

Actuarial and reproductive senescence in a long-lived seabird: preliminary evidence

The evolutionary theory of aging predicts that pelagic seabirds, which have low extrinsic mortality, should show exceptional longevity. These taxa appear to show the lowest rates of actuarial senescence among birds yet display declining reproductive performance at advanced ages. We have studied survival and reproduction of Nazca boobies (Sula granti) in the remote Galápagos Islands since 1984. We found a slight but detectable increase in mortality rate in the oldest (> or =19 yrs) cohort, indicating minimal actuarial senescence. The probability of successful reproduction (eggs or fledglings) declined from mid-life to the age of the oldest cohort. We are currently investigating the causal relationship between physical (foraging) performance, components of reproductive success, and longevity at our pristine study site.

T helper 1-type immunity to trophoblast antigens in women with a history of recurrent pregnancy loss is associated with polymorphism of the IL1B promoter region

Recurrent pregnancy loss (RPL) is a common disorder during early gestation. Recent evidence suggests that T helper 1 (Th1)-type immunity is associated with unsuccessful pregnancy especially in women with RPL of otherwise unknown etiology, while Th2-type immunity is associated with pregnancy success. Interleukin (IL)-1 may influence Th1/Th2 immune responsiveness and has been implicated in the establishment of successful pregnancy. In the present study, we investigated polymorphism of the IL-1beta gene (IL1B) in women with a history of RPL. Significant increases in the frequencies of IL1B promoter region variants IL1-511C and IL1B-31T were found in women with a history of RPL. Increased frequencies of these two variants and their homozygotes were found only in cases having evidence of Th1 immunity to trophoblast as determined by IFN-gamma production of peripheral blood mononuclear cells (PBMCs) stimulated with a trophoblast cell-line extract. Significantly higher IFN-gamma production by PBMCs in response to trophoblast correlated with variant IL1B-511C and its homozygocity in women with RPL. These results suggest that variants -511C and -31T in the IL1B promoter region confer risk for RPL associated with Th1 immunity to trophoblast antigens.

Stem and progenitor cells: origins, phenotypes, lineage commitments, and transdifferentiations

Multipotent stem cells are clonal cells that self-renew as well as differentiate to regenerate adult tissues. Whereas stem cells and their fates are known by unique genetic marker studies, the fate and function of these cells are best studied by their prospective isolation. This review is about the properties of various highly purified tissue-specific multipotent stem cells and purified oligolineage progenitors. We contend that unless the stem or progenitor cells in question have been purified to near homogeneity, one cannot know whether their generation of expected (or unexpected) progeny is a property of a known cell type. It is interesting that in the hematopoietic system the only long-term self-renewing cells in the stem and progenitors pool are the hematopoietic stem cells. This fact is discussed in the context of normal and leukemic hematopoiesis.

The bHLH transcription factor Olig2 promotes oligodendrocyte differentiation in collaboration with Nkx2.2

Olig2, a basic helix-loop-helix (bHLH) transcription factor, is expressed in a restricted domain of the spinal cord ventricular zone that sequentially generates motoneurons and oligodendrocytes. Just prior to oligo-dendrocyte precursor formation, the domains of Olig2 and Nkx2.2 expression switch from being mutually exclusive to overlapping, and Neurogenins1 and 2 are extinguished within this region. Coexpression of Olig2 with Nkx2.2 in the spinal cord promotes ectopic and precocious oligodendrocyte differentiation. Both proteins function as transcriptional repressors in this assay. This effect is blocked by forced expression of Neurogenin1. By contrast, misexpression of Olig2 alone derepresses Neurogenins and promotes motoneuron differentiation. Olig2 therefore functions sequentially in motoneuron and oligodendrocyte fate specification. This dual action is enabled by spatio-temporal changes in the expression domains of other transcription factors with which Olig2 functionally interacts.

A diverse family of GPCRs expressed in specific subsets of nociceptive sensory neurons

In vertebrates, peripheral chemosensory neurons express large families of G protein-coupled receptors (GPCRs), reflecting the diversity and specificity of stimuli they detect. However, somatosensory neurons, which respond to chemical, thermal, or mechanical stimuli, are more broadly tuned. Here we describe a family of approximately 50 GPCRs related to Mas1, called mrgs, a subset of which is expressed in specific subpopulations of sensory neurons that detect painful stimuli. The expression patterns of mrgs thus reveal an unexpected degree of molecular diversity among nociceptive neurons. Some of these receptors can be specifically activated in heterologous cells by RFamide neuropeptides such as NPFF and NPAF, which are analgesic in vivo. Thus, mrgs may regulate nociceptor function and/or development, including the sensation or modulation of pain.

The molecular basis of nonoxynol-9-induced vaginal inflammation and its possible relevance to human immunodeficiency virus type 1 transmission

Topical microbicides are being sought to prevent sexually transmitted diseases by inactivating pathogens while preserving or enhancing the natural mucosal barrier. Serious public health concerns were raised by a recent phase 3 clinical trial that showed that nonoxynol-9 (N-9), a leading microbicide candidate widely used as an over-the-counter spermicide, may actually increase human immunodeficiency virus type 1 (HIV-1) transmission. The present study links N-9-induced vaginal inflammation to increased risk of HIV-1 infection. Analysis of molecular and cellular components in cervicovaginal secretions, as well as results from in vitro activation of cervicovaginal epithelial cells and U1/HIV promonocytic cells, showed that multiple N-9 use can promote HIV-1 transmission through interleukin-1-mediated NF-kappaB activation, which leads to chemokine-induced recruitment of HIV-1 host cells and increased HIV-1 replication in infected cells. Furthermore, this study identifies in vitro and in vivo model systems for monitoring undesirable proinflammatory effects of microbicides and other vaginal products.

Hormonal correlates of siblicide in Galápagos Nazca boobies

Nazca boobies (Sula granti) show unconditional obligate siblicide immediately after hatching, reducing the typical two-egg clutch size to one. We studied body mass changes and levels of testosterone (T), corticosterone (CORT), and progesterone (P) for A-chicks (dominant, first hatched), B-chicks (subordinate, second hatched), and singletons, during the first 7 days after hatching, when siblicide normally occurs. Mass increase with age was higher for A-chicks than for singletons and B-chicks. This exaggerated the existing developmental advantage of A- over B-chicks that is due to hatching asynchrony. In nests with two chicks, CORT titer was significantly higher in B-chicks than in A-chicks. During ontogenetic development, CORT decreased with age for A-chicks, but did not change for singletons. P showed qualitatively similar ontogenetic changes to CORT, remaining unchanged for A-chicks but increasing for singletons. Thus, both CORT and P levels were lower for A-chicks than for singletons, and both hormones varied inversely with body mass. Overall, T levels did not differ between different categories of chicks. However, one B-chick in the process of reversing the dominance relationship with its older, but weakened, sibling had significantly elevated T. We suggest that CORT and P are regulated to promote exaggerated mass gain in socially challenged A-chicks, facilitating siblicide. Whether T induces aggressiveness during short time intervals of intense sibling rivalry needs further attention.

Surface modification of neural recording electrodes with conducting polymer/biomolecule blends

The interface between micromachined neural microelectrodes and neural tissue plays an important role in chronic in vivo recording. Electrochemical polymerization was used to optimize the surface of the metal electrode sites. Electrically conductive polymers (polypyrrole) combined with biomolecules having cell adhesion functionality were deposited with great precision onto microelectrode sites of neural probes. The biomolecules used were a silk-like polymer having fibronectin fragments (SLPF) and nonapeptide CDPGYIGSR. The existence of protein polymers and peptides in the coatings was confirmed by reflective microfocusing Fourier transform infrared spectroscopy (FTIR). The morphology of the coating was rough and fuzzy, providing a high density of bioactive sites for interaction with neural cells. This high interfacial area also helped to lower the impedance of the electrode site and, consequently, to improve the signal transport. Impedance spectroscopy showed a lowered magnitude and phase of impedance around the biologically relevant frequency of 1 kHz. Cyclic voltammetry demonstrated the intrinsic redox reaction of the doped polypyrrole and the increased charge capacity of the coated electrodes. Rat glial cells and human neuroblastoma cells were seeded and cultured on neural probes with coated and uncoated electrodes. Glial cells appeared to attach better to polypyrrole/SLPF-coated electrodes than to uncoated gold electrodes. Neuroblastoma cells grew preferentially on and around the polypyrrole/CDPGYIGSR-coated electrode sites while the polypyrrole/CH(3)COO(-)-coated sites on the same probe did not show a preferential attraction to the cells. These results indicate that we can adjust the chemical composition, morphology, electronic transport, and bioactivity of polymer coatings on electrode surfaces on a multichannel micromachined neural probe by controlling electrochemical deposition conditions.

Cardiac conduction abnormalities in endocarditis defined by the Duke criteria

BACKGROUND

Cardiac conduction abnormalities occur in endocarditis and have been associated with infection extension and increased mortality. There have been no prospective studies of electrocardiographic (ECG) conduction changes in endocarditis. We examined the incidence of ECG changes in a large prospective cohort with suspected endocarditis and correlated changes with echocardiographic evidence of invasive infection and mortality.

METHODS

One hundred thirty-seven of 1396 (10%) suspected cases of endocarditis were classified as "definite" or "possible" by the Duke criteria and had an interpretable ECG. ECG conduction changes were classified as old (pre-existing hospitalization), new (evident on admission or developed during hospitalization), or indeterminate. New or indeterminate abnormalities were considered "ECG conduction changes." Echocardiogram results were reviewed to identify infected valves and invasive infection.

RESULTS

ECG conduction changes were present in 36 of 137 (26%) patients. Patients with ECG conduction changes were more often male (69% vs 46%, P =.005) and had prosthetic valves (47% vs 23%, P <.001). There were no significant differences in microbiology results or treatment with cardiac surgery. In 76 (55%) patients, at least one infected valve was identified by echocardiography; 15 of 76 (20%) patients were determined to have evidence of invasive infection. Eight of 15 (53%) invasive infections exhibited ECG conduction changes compared with 16 of 61 (26%) isolated valve infections (P =.046). Eleven of 36 (31%) patients with ECG conduction changes died during hospitalization compared with 15 of 101 (15%) patients without changes (P =.039).

CONCLUSIONS

ECG conduction changes commonly occur in endocarditis despite more sensitive diagnostic criteria and are associated with increased mortality and invasive infection.

The paired homeodomain protein DRG11 is required for the projection of cutaneous sensory afferent fibers to the dorsal spinal cord

Cutaneous sensory neurons that detect noxious stimuli project to the dorsal horn of the spinal cord, while those innervating muscle stretch receptors project to the ventral horn. DRG11, a paired homeodomain transcription factor, is expressed in both the developing dorsal horn and in sensory neurons, but not in the ventral spinal cord. Mouse embryos deficient in DRG11 display abnormalities in the spatio-temporal patterning of cutaneous sensory afferent fiber projections to the dorsal, but not the ventral spinal cord, as well as defects in dorsal horn morphogenesis. These early developmental abnormalities lead, in adults, to significantly attenuated sensitivity to noxious stimuli. In contrast, locomotion and sensori-motor functions appear normal. Drg11 is thus required for the formation of spatio-temporally appropriate projections from nociceptive sensory neurons to their central targets in the dorsal horn of the spinal cord.

Treatment of femoral fractures in children by pediatric orthopedists: results of a 1998 survey

SUMMARY

This study aimed to determine treatment preference of various femoral fracture patterns in children by pediatric orthopedists and whether it is practice dependent. In September 1998, members of the Pediatric Orthopedic Society of North America were surveyed to determine their current preferences in treating each of four middle one-third femoral fracture patterns in four age groups. Forty-four percent (286/656) of those surveyed responded. For each fracture pattern, operative treatment was increasingly preferred over nonoperative as patient age increased, and the preferred treatments within the operative and nonoperative categories changed significantly as patient age increased. Fourteen specific cases of femoral head avascular necrosis were noted after rigid reamed and unreamed rodding. There is a statistically significant trend by pediatric orthopedists to treat older children's femur fractures operatively and younger children's nonoperatively. The consensus treatment is age dependent. The numerous cases of avascular necrosis after rigid rodding are a concern.

The risk of stroke and death in patients with aortic and mitral valve endocarditis

BACKGROUND

Previous studies have generated inconsistent results when attempting to define predictors of stroke and death in patients with endocarditis. We sought to examine the relationship between vegetation 2-dimensional size and stroke in those with infective endocarditis (IE) and to identify differences between aortic valve (AV) and mitral valve (MV) IE with regard to clinical characteristics, echocardiographic findings, stroke, and death.

METHODS

We used the Duke Endocarditis Database to examine 145 episodes of definite IE involving the AV, n = 62, or MV, n = 83. A logistic regression model was developed to analyze important variables in predicting stroke, and a Cox proportional hazards model was used in predicting mortality.

RESULTS

The mitral valve was infected in 57% of the cases. Vegetations were more commonly detected in patients with MV IE (92.8% vs 66.1%, P =.001) and these MV vegetations were significantly larger (P <.05). Thirty-four of 145 episodes (23.4%) were complicated by stroke. MV IE was associated with a greater stroke rate, 32.5% versus 11.3% (P =.003). Strokes tended to occur early in the course of illness, particularly in MV IE. In the multivariable model, the independent predictors of stroke were MV IE (P =.04) and vegetation length (P =.03). Independent predictors of 1-year mortality were age (P =.02) and vegetation area (P =.048).

CONCLUSION

Stroke is more common in patients with MV IE. Vegetation 2-dimensional size and characteristics are important predictors of stroke and mortality. These findings may lead to predictive models that allow physicians to identify high-risk patients who need aggressive treatment strategies to prevent long-term morbidity and mortality.

A systems approach to the reduction of medication error on the hospital ward

AIMS

To discuss a potentially powerful approach to safer medication administration on the hospital ward, based on principles of safety developed in other high-risk industries, and consistent with recent national reports on safety in health care released in the United Kingdom (UK) and United States of America (USA). To discuss why punitive approaches to safety on the hospital ward and in the nursing literature do not work.

BACKGROUND

Drug administration error on the hospital ward is an ever-present problem and its occurrence is too frequent. Administering medication is probably the highest-risk task a nurse can perform, and accidents can lead to devastating consequences for the patient and for the nurse's career. Drug errors in nursing are often dealt with by unsystematic, punitive, and ineffective means, with little knowledge of the factors influencing error generation. Typically, individual nurses are simply blamed for their carelessness. By focusing on the individual, the complete set of contributing factors cannot be known. Instead, vain attempts will be made to change human behaviour - one of the most change-resistant aspects of any system. A punitive, person-centred approach therefore, severely hampers effective improvements in safety. By contrast, in other high-risk industries, such as aviation and nuclear power, the systems-centred approach to error reduction is routine.

CONCLUSIONS

Accidents or errors are only the tip of the incident iceberg. Through effective, nonpunitive incident reporting, which includes reports of near-misses and system problems in addition to actual accidents, the systems-approach allows the complete set of contributing factors underlying an accident to be understood and addressed. Feedback to participants and targeted improvement in the workplace is also important to demonstrate that incident data are being used appropriately, and to maintain high levels of on-going reporting and enthusiasm for the scheme. Drug administration error is a serious problem, which warrants a well-reasoned approach to its improvement.

Leukocyte activation in the decidua of chromosomally normal and abnormal fetuses from women with recurrent abortion

As part of our continuing programme to investigate immunological causes of unexplained recurrent pregnancy losses, we studied subpopulations of white blood cells and their activation status in decidua of women with a history of recurrent spontaneous abortion (RSA). We differentiated specifically between normal karyotyped male fetuses and abnormal karyotyped fetuses with trisomy 16 because trisomy 16 is not compatible with life and is thus a non-controversial cause of spontaneous miscarriage. Leukocytes were counted in paraffin-embedded decidua after immunohistological staining for CD45 (LCA), CD3, CD56, CD68, CD69 and CD25. Numbers of activated versus non-activated T lymphocytes, NK cells and macrophages were compared in decidua from women with: (i) unexplained RSA who had a normal male karyotype (n = 17) miscarriage; (ii) unexplained RSA who had a trisomy 16 (n = 21) miscarriage; and (iii) normal gestationally age-matched first trimester pregnancies following elective termination procedures (n = 20). Significantly more activated leukocytes were detected in the decidua of women with unexplained RSA who had a normal male karyotype compared to the other groups (P < 0.0001). In addition, numbers of cells comprising the major leukocyte subpopulation, CD56+ NK cells, appeared reduced in the decidua of women with unexplained RSA compared to decidua from women having elective terminations. Increased numbers of activated leukocytes in the decidua of women with a history of unexplained recurrent pregnancy loss who had a normal karyotyped pregnancy provide evidence that cellular immunity may be involved in unexplained recurrent pregnancy loss.

Cost-effectiveness of spinal cord stimulation in patients with intractable angina

AIM

To review the cost of healthcare utilisation by patients suffering from intractable angina, unsuitable for coronary revascularisation, before and after treatment with spinal cord stimulation.

METHODS

Data were collected for eight patients treated for intractable angina with spinal cord stimulation at Green Lane Hospital before April 1999. Information on consumption of specified medica resources for the twelve months preceding implantation, the implantation period, and the twelve months following implantation was collected. Where available, data were also collected for the eighteen months preceding and following treatment.

RESULTS

In six patients successful permanent stimulation was established; in two it proved technically impossible to implant a stimulator. The six patients with successful stimulation spent fewer days in hospital (p=0.028) and consumed fewer resources (p=0.046) following implantation than in the period before implantation. The two patients for whom spinal cord stimulation was unsuccessful spent more days in hospital and consumed more resources in the twelve months following, than in the twelve months preceding attempted implantation. Extrapolation of data for all eight patients suggests that, on average, the cost of implanting a spinal cord stimulator will be recovered in approximately fifteen months.

CONCLUSION

Spinal cord stimulation is a cost-effective treatment for intractable angina pectoris.