MOJE ceramic metatarsophalangeal arthroplasty: disappointing clinical results at two to eight years

BACKGROUND

Among the surgical treatment options for osteoarthritis of the first metatarsophalangeal joint (MTPJ) are a number of different designs of total arthroplasty, including the MOJE, a ceramic press fit arthroplasty. We present a 2- to 8-year followup of 31 procedures.

METHODS

Thirty-two MOJE arthroplasties were undertaken for painful hallux rigidus in 30 patients (nine male, 21 female) over 6 years (mean age 61.9; range, 37 to 76). At followup patients' symptoms, levels of function and radiographs were scored using SF-36, modified Kitaoka and AOFAS systems. Followup rate was 97%, with mean followup time 58 months (range, 28 to 97).

RESULTS

Mean scores were: Kitaoka 53.8 (15 to 75), AOFAS 61.3/100 (range, 18 to 100), SF-36 physical combined 48.6 (27.6 to 58.7) SF-36 mental score 52.2 (19.5 to 62.2). Sixteen showed radiological evidence of component loosening (either lucency, subsidence or both) and one radiograph revealed component fracture. Eight implants have been revised. In patients who had not undergone subsequent fusion, 15 had less than 36 degrees of movement, nine had 36 to 45 degrees, four were in the 46 to 60 range, and only one had more than 60 degrees. There were no infections.

CONCLUSION

Although previous studies have suggested favorable initial outcomes with the MOJE prosthesis, all have focused only on the early results. In our series, the reoperation rate of 26% at up to 8 years is worryingly high, especially given that 16 (52%) showed loosening. Although there appears to be a cohort of patients who have satisfactory outcomes with the MOJE, we would suggest the continued use of this implant.

Current views on the management of atherosclerotic renovascular disease

Atherosclerotic renovascular disease (ARVD) is a common condition in both elderly patients and those with other vascular disease. No published randomized controlled trial has demonstrated an overall benefit of revascularization on any clinical or biochemical end-point, and optimal medical therapy in this condition is not clearly defined. In this review we consider the epidemiology of ARVD and discuss the evidence for current medical treatment. We also address the literature on revascularization, consider settings in which an interventional approach may still be considered, and touch upon on-going areas of research.

Maternal deaths in women with lupus nephritis: a review of published evidence

BACKGROUND AND OBJECTIVES

Pregnancies in women with systemic lupus erythematosus (SLE) and lupus nephritis are considered high-risk due to high rates of maternal and fetal complications. However, there has not been a formal analysis addressing the issue of maternal deaths in these women. The aim of this study was to perform a literature review of the maternal deaths in women with SLE and lupus nephritis to: (1) identify the main causes of death and (2) discuss possible reasons for these causes, and strategies that may improve patient care and outcomes. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENT: We performed an extensive electronic literature search from 1962 to 2009 using online databases (PubMed, Embase, Lilacs, Cochrane Controlled Trials Register, Medline, and Science Citation Index). Studies were included if they reported pregnancies in patients with SLE and lupus nephritis with at least one reported maternal death.

RESULTS

We identified 13 studies that reported a total of 17 deaths in the 6 week post-partum period that were attributable to SLE and lupus nephritis. In all cases, death occurred in the setting of active disease, and was attributed either to infection in 41.2% (n = 7), or disease activity in 29.4% (n = 5). The remaining deaths were due to pulmonary embolus in 11.8% (n = 2), pregnancy-associated cardiomyopathy in 5.9% (n = 1), adrenal failure due to abrupt steroid withdrawal in 5.9% (n = 1), and undefined in 5.9% (n = 1).

CONCLUSIONS

All maternal deaths in patients with SLE and lupus nephritis occurred in those with active disease, with disease activity/complications and infections (mainly opportunistic) being the two major causes. The presented evidence further supports timing of pregnancy relative to SLE activity, and the judicious use of immunosuppressive agents in pregnant patients.

Relationship between dose, drug levels, and D2 receptor occupancy for the atypical antipsychotics risperidone and paliperidone

Blockade of D2 family dopamine receptors (D2Rs) is a fundamental property of antipsychotics, and the degree of striatal D2R occupancy has been related to antipsychotic and motor effects of these drugs. Recent studies suggest the D2R occupancy of antipsychotics may differ in extrastriatal regions compared with the dorsal striatum. We studied this issue in macaque monkeys by using a within-subjects design. [(18)F]fallypride positron emission tomography scans were obtained on four different doses of risperidone and paliperidone (the 9-OH metabolite of risperidone) and compared with multiple off-drug scans in each animal. The half-life of the two drugs in these monkeys was determined to be between 3 and 4 h, and drug was administered by a constant infusion through an intragastric catheter. The D2R occupancy of antipsychotic was determined in the caudate, putamen, ventral striatum, and four prefrontal and temporal cortical regions and was related to serum and cerebrospinal fluid drug levels. Repeated 2-week treatment with risperidone or paliperidone did not produce lasting changes in D2R binding potential in any region examined. As expected, D2R binding potential was highest in the caudate and putamen and was approximately one-third that level in the ventral striatum and 2% of that level in the cortical regions. We found dose-dependent D2R occupancy for both risperidone and paliperidone in both basal ganglia and cortical regions of interest. We could not find evidence of regional variation in D2R occupancy of either drug. Comparison of D2R occupancy and serum drug levels supports a target of 40 to 80 ng/ml active drug for these two atypical antipsychotics.

Positional cloning of a quantitative trait locus contributing to pain sensitivity: possible mediation by Tyrp1

To identify novel pain-relevant genes, a set of 35 recombinant congenic strains derived from the sensitive C57BL/6 and resistant A/J strains were tested for their sensitivity to noxious heat on the radiant heat paw-withdrawal test. Nine strains were found to display differential sensitivity, and the two most extreme responders were used to generate independent secondary crosses for quantitative trait locus (QTL) mapping. From these genetic analyses, a QTL, which we call Tpnr5, was mapped to a 14-Mb interval of mouse chromosome 4 containing 39 genes. In addition to the paw-withdrawal test phenotype, Tpnr5 may be relevant to mechanical and inflammatory nociception. A series of strategies - including in silico analyses, reverse transcriptase polymerase chain reaction (RT-PCR) in multiple tissues and exonic DNA sequencing - were used to generate a list of six prioritized candidate genes. One of these, tyrosinase-related protein 1 (Tyrp1), displayed enriched expression in the dorsal root ganglia, an inactivating (C110Y) mutation in the resistant A/J strain, and a null mutant found to be more resistant to thermal nociception compared to its wild-type counterpart. Although other genes cannot be definitively ruled out, existing data are supportive of the candidacy of Tyrp1 as representing the Tpnr5 QTL. Tyrosinase-related protein 1 is the rate-limiting enzyme in the production of eumelanin, and possible relationships between eumelanin-expressing cells and thermal nociception are discussed. The positional cloning of Tpnr5 is also considered in light of the heuristic value but continuing challenges of QTL mapping in the mouse.

The journey to regulation of protein-based multiplex quantitative assays

BACKGROUND

Clinical proteomics presents great promise in biology and medicine because of its potential for improving our understanding of diseases at the molecular level and for detecting disease-related biomarkers for diagnosis, prognosis, and prediction of therapeutic responses. To realize its full potential to improve clinical outcome for patients, proteomic studies have to be well designed, from biosample cohorts to data and statistical analyses. One key component in the biomarker development pipeline is the understanding of the regulatory science that evaluates diagnostic assay performance through rigorous analytical and clinical review criteria.

CONTENT

The National Cancer Institute's Clinical Proteomic Technologies for Cancer (CPTC) initiative has proposed an intermediate preclinical "verification" step to close the gap between protein-based biomarker discovery and clinical qualification. In collaboration with the US Food and Drug Administration (FDA), the CPTC network investigators recently published 2 mock submission review documents, first-of-their-kind educational materials that may help the scientific community interested in developing products for the clinic in understanding the likely analytical evaluation requirements for multiplex protein technology-based diagnostic tests.

CONCLUSIONS

Building on this momentum, the CPTC continues with this report its collaboration with the FDA, as well as its interactions with the AACC and the Centers for Medicare and Medicaid Services, to further the understanding of regulatory requirements for approving multiplex proteomic platform-based tests and analytically validating multiple analytes.

ADAMTS-5 deficient mice do not develop mechanical allodynia associated with osteoarthritis following medial meniscal destabilization

OBJECTIVE

To characterize pain-related behavior during the course of knee osteoarthritis (OA) induced by destabilization of the medial meniscus (DMM) in wild type (WT) and in ADAMTS-5 null mice.

METHODS

DMM surgery was performed in the right knee of CD-1 mice. At regular intervals up to 8 weeks after surgery, mice were assessed for the following parameters: mechanical allodynia (via withdrawal thresholds to von Frey filaments applied to the plantar surface of both hind paws or to the tail), thermal hyperalgesia, locomotor activity and gait analysis. In addition, mechanical allodynia was tested in C57BL/6 WT or ADAMTS-5 null mice following DMM surgery.

RESULTS

In CD-1 mice, a robust and progressive decrease in withdrawal threshold was observed in both hind paws after DMM but not sham surgery. Allodynia was apparent as early as 14 days postoperatively. Both sexes developed OA changes after surgery with concurrent mechanical allodynia. No other pain-related behavioral changes were detected up to 8 weeks post-surgery. In C57BL/6 mice, a genetic background in which only males develop OA changes after DMM, males but not females developed allodynia in the ipsilateral hind paw. In contrast, C57BL/6 ADAMTS-5 null mice did not develop OA changes or mechanical allodynia up to 8 weeks post-surgery.

CONCLUSION

Joint pathology following DMM surgery in mice is associated with progressive mechanical allodynia. ADAMTS-5 null mice are resistant to DMM-induced OA-like lesions and to the associated mechanical allodynia.

Gnao1 (G alphaO protein) is a likely genetic contributor to variation in physical dependence on opioids in mice

Chronic exposure to opioids leads to physical dependence, which manifests as the symptoms of drug withdrawal. Interindividual differences in withdrawal symptom severity are well known, and at least partially due to genetic variation. To identify genes contributing to variation in withdrawal severity, we chronically treated 30 strains of the AcB/BcA recombinant congenic mouse strain set, including their A/J and C57BL/6J (B6) progenitors, with morphine for seven days and compared jumping frequencies--a sensitive and widely used index of withdrawal magnitude--during naloxone-precipitated withdrawal (NPW). Jumping frequencies of B6 mice were more than threefold greater than values obtained in A/J mice. Visual inspection of the genomic distribution of parental haplotypes in the AcB/BcA strains identified a putative quantitative trait locus (QTL) localized to chromosome 8 (90-117 Mb), and this QTL was confirmed in a B6AF2 intercross. The most salient candidate gene within this QTL, Gnao1 (guanine nucleotide binding protein, alpha(o); G alpha(o); 96.3 Mb), was tested for functional relevance using quantitative PCR and an antisense oligodeoxynucleotide strategy. The expression of Gnao1 in the locus coeruleus was found to be upregulated in morphine-dependent B6 but not A/J mice. Antisense knockdown of Gnao1 reduced NPW jumping in B6, but not A/J, mice rendered dependent on either morphine or heroin, largely rescuing the original strain difference. These data strongly implicate the G alpha(o) protein in the locus coeruleus as contributing to interindividual variability in physical dependence on opioids in mice.

Genetic and environmental influences on systemic markers of inflammation in middle-aged male twins

OBJECTIVES

The aims of this study were to determine the relative influence of genetic and environmental contributions to inflammatory biomarkers, and to what extent correlations among these markers are due to genetic or environmental factors.

METHODS

We performed univariate and multivariate genetic analyses of four inflammatory markers: interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), C-reactive protein (CRP), and fibrinogen, in 166 (88 monozygotic and 78 dizygotic) middle-aged male twin pairs.

RESULTS

The mean age (+/-S.D.) of the twins was 54 (+/-2.93) years. Heritability was substantial for CRP (0.61, 95% CI: 0.47-0.72) and moderate to fair for IL-6 (0.31, 0.13-0.46), sIL-6R (0.49, 0.30-0.76) and fibrinogen (0.52, 0.34-0.65). IL-6, CRP and fibrinogen showed significant correlations, but not with sIL-6R. Multivariate genetic analysis found that these correlations could be best explained by a common pathway model, where the common factor explained 27%, 73% and 25% of the variance of IL-6, CRP and fibrinogen, respectively. About 46% (95% CI: 21-64%) of the correlations among the three inflammatory markers could be explained by the genetic factors. After adjusting for covariates known to influence inflammation levels, heritability estimates were slightly decreased but the overall results remained similar.

CONCLUSIONS

A significant part of the variation in inflammatory marker levels is due to genetic influences. Furthermore, almost 50% of the shared variance among these biomarkers is due to a common genetic factor which likely plays a key role in the regulation of inflammation.

Lithium in breast milk and nursing infants: clinical implications

OBJECTIVE

Current practice guidelines discourage use of lithium during breast-feeding, despite limited data. This study aimed to quantify lithium exposure in nursing infants.

METHOD

In 10 mother-infant pairs, the authors obtained assays of lithium in maternal serum, breast milk, and infant serum and indices of infant renal and thyroid function.

RESULTS

Maternal serum, breast milk, and infant serum daily trough concentrations of lithium averaged 0.76, 0.35, and 0.16 meq/liter, respectively, each lithium level lower than the preceding level by approximately one-half. No serious adverse events were observed, and elevations of thyroid-stimulating hormone, blood urea nitrogen, and creatinine were few, minor, and transient.

CONCLUSIONS

Serum lithium levels in nursing infants were low and well tolerated. No significant adverse clinical or behavioral effects in the infants were noted. These findings encourage reassessment of recommendations against lithium during breast-feeding and underscore the importance of close clinical monitoring of nursing infants.

Melanocortin-1 receptor gene variants affect pain and mu-opioid analgesia in mice and humans

BACKGROUND

A recent genetic study in mice and humans revealed the modulatory effect of MC1R (melanocortin-1 receptor) gene variants on kappa-opioid receptor mediated analgesia. It is unclear whether this gene affects basal pain sensitivity or the efficacy of analgesics acting at the more clinically relevant mu-opioid receptor.

OBJECTIVE

To characterise sensitivity to pain and mu-opioid analgesia in mice and humans with non-functional melanocortin-1 receptors.

METHODS

Comparisons of spontaneous mutant C57BL/6-Mc1r(e/e) mice to C57BL/6 wildtype mice, followed by a gene dosage study of pain and morphine-6-glucuronide (M6G) analgesia in humans with MC1R variants.

RESULTS

C57BL/6-Mc1r(e/e) mutant mice and human redheads--both with non-functional MC1Rs--display reduced sensitivity to noxious stimuli and increased analgesic responsiveness to the mu-opioid selective morphine metabolite, M6G. In both species the differential analgesia is likely due to pharmacodynamic factors, as plasma levels of M6G are similar across genotype.

CONCLUSIONS

Genotype at MC1R similarly affects pain sensitivity and M6G analgesia in mice and humans. These findings confirm the utility of cross species translational strategies in pharmacogenetics.

Relation of low socioeconomic status to C-reactive protein in patients with coronary heart disease (from the heart and soul study)

Low socioeconomic status (SES) is associated with poor health outcomes in patients who have coronary heart disease (CHD). Inflammation is a potential mechanism by which low SES may lead to adverse cardiovascular outcomes, but it is not known whether low SES is associated with inflammation in patients who have CHD. We measured high-sensitivity C-reactive protein (CRP) levels in a cross-sectional study of 985 adults who had CHD. Income and education were determined by self-report. We used ordinal logistic regression to examine the association of income and education with CRP. Of the 985 participants, 390 had high CRP levels (>3 mg/dl). The proportion of participants who had high CRP levels ranged from 30% (103 of 340) in those who had a college degree to 51% (65 of 127) in those who had less than a high school degree (p<0.0001). The proportion of subjects who had a high CRP level ranged from 28% (52 of 183) in those who had annual income>or=$50,000 to 42% (199 of 974) in those who had an annual income<$20,000 (p<0.001). After adjustment for traditional cardiovascular risk factors and other potential confounding variables, lower income and education remained associated with higher CRP levels. In conclusion, low SES is associated with high CRP levels in patients who have CHD. This observation raises the possibility that inflammation may contribute to the adverse cardiovascular outcomes associated with low SES.

Cytologic findings and protein expression profiles associated with ductal carcinoma of the breast in ductal lavage specimens using surface-enhanced laser desorption and ionization-time of flight mass spectrometry

BACKGROUND

Early detection of breast carcinoma enhances the chances for patient survival. The authors' work focused on an innovative technique that couples breast ductal lavage (DL) with surface-enhanced laser desorption and ionization-time of flight mass spectrometry (SELDI-TOF MS) to yield a highly sensitive and specific method of breast carcinoma detection.

METHODS

The study group included 16 women who had unilateral, biopsy-proven breast carcinoma. Studying paired DL specimens from each woman (the breast with and the breast without carcinoma), a cytologic investigation was performed on the cells present in the DL samples, and the protein content of the DL fluid was analyzed with the SELDI-TOF MS technique using the strong anionic exchange chip surface.

RESULTS

Only 5 of 16 DL specimens (31%) from breasts with biopsy-proven carcinoma contained malignant cells, whereas the remaining samples contained only histiocytes and clusters of benign ductal epithelium. In contrast, 12 of 16 DL specimens (75%) from breasts that contained carcinoma had a different protein peak pattern compared with the paired DL specimen from the same patient's contralateral, uninvolved breast. This finding was independent of the presence of neoplastic cells in the lavage fluid. In addition, specific protein peaks, which may represent potential biomarkers, were identified in the DL fluids from breasts with carcinoma. Some of these peaks were conserved between different patients.

CONCLUSIONS

The combination of breast DL with SELDI-TOF MS offers a unique and powerful technique for the detection and monitoring of breast carcinoma. This method has the potential to enhance the diagnostic utility of conventional DL cytology.

Effect of in vivo lymphocyte-depleting strategies on development of lymphoproliferative disorders in children post allogeneic bone marrow transplantation

T cell depletion (TCD) of marrow is a proven method of graft-versus-host disease (GVHD) prophylaxis in allogeneic bone marrow transplantation (BMT). Nonetheless, TCD is associated with an increased risk of developing post transplant lymphoproliferative disorder (PTLD). Between 1986 and 1998, 241 pediatric patients at the University of Iowa underwent BMT using ex vivo TCD of marrow from mismatched related or matched unrelated donors. Additional GVHD prophylaxis included antithymocyte globulin (ATG) or anti lymphocyte globulin (ALG) post transplant (in vivo TCD). A total of 30 cases of PTLD were identified based upon a combination of clinical, histological, and immunological features. Nearly all cases occurred within 3 months post BMT. A statistically significant increase in PTLD incidence was noted for patients treated with ATG vs ALG (33 vs 9%). While grade I-II acute GVHD was more common in patients receiving ATG vs ALG, no difference in grade III-IV GVHD or overall survival was noted between the two groups. Assessment of immune recovery at various times post BMT revealed significantly fewer T cells in the ATG-treated group, suggesting the deleterious effect of ATG may be due to excessive depletion of donor-derived Epstein-Barr virus-specific cytotoxic T cells. Thus, caution should be exercised in the use of anti-T-cell antibody therapy for additional GVHD prophylaxis in the setting of TCD BMT.

Cardiovascular autonomic function in systemic lupus erythematosus

AIM

To determine whether cardiovascular autonomic function is impaired in systemic lupus erythematosus (SLE).

METHODS

A case-control study of 23 patients with SLE was performed. Autonomic symptoms were assessed using a standard questionnaire. Cardiovascular autonomic function was measured using 10 non-invasive investigations. There were significant differences between patients and controls in three out of 24 parameters measured during the different tests (P < 0.002). These were reduction in systolic blood pressure at 5 min on head-up tilt, and heart rate responses to isometric exercise and cutaneous cold. Eleven out of 23 patients had an abnormal heart rate, blood pressure or Valsalva response (value below the age corrected 5th centile) while testing compared with six of the controls. Plasma adrenaline and noradrenaline levels were significantly lower in patients vs controls in both the supine (P < 0.05) and tilt position (P < 0.01). Twenty-one of the 23 patients had one or more symptoms that may be attributable to abnormalities in autonomic function. There was no significant association between the number of symptoms and presence of autonomic dysfunction. Cardiovascular autonomic impairment may be demonstrated in some patients with SLE. Symptoms attributable to autonomic dysfunction are common in SLE and autonomic assessment may be required.