Iron deposition on SWI-filtered phase in the subcortical deep gray matter of patients with clinically isolated syndrome may precede structure-specific atrophy

BACKGROUND AND PURPOSE

Increasing evidence suggests that iron deposition is present in the later stages of MS. In this study we examined abnormal phase values, indicative of increased iron content on SWI-filtered phase images of the SDGM in CIS patients and HC. We also examined the association of abnormal phase with conventional MR imaging outcomes at first clinical onset.

MATERIALS AND METHODS

Forty-two patients with CIS (31 female, 11 male) and 65 age and sex-matched HC (41 female, 24 male) were scanned on a 3T scanner. Mean age was 40.1 (SD = 10.4) years in patients with CIS, and 42.8 (SD = 14) years in HC, while mean disease duration was 1.2 years (SD = 1.3) in patients with CIS. MP-APT, NPTV, and normalized volume measurements were derived for all SDGM structures. Parametric and nonparametric group-wise comparisons were performed, and associations were determined with other MR imaging metrics.

RESULTS

Patients with CIS had significantly increased MP-APT (P = .029) and MP-APT volume (P = .045) in the pulvinar nucleus of the thalamus compared with HC. Furthermore, the putamen (P = .004), caudate (P = .035), and total SDGM (P = .048) displayed significant increases in MP-APT volume, while MP-APT was also significantly increased in the putamen (P = .029). No global or regional volumetric MR imaging differences were found between the study groups. Significant correlations were observed between increased MP-APT volumes of total SDGM, caudate, thalamus, hippocampus, and substantia nigra with white matter atrophy and increased T2 lesion volume (P < .05).

CONCLUSION

Patients with CIS showed significantly increased content and volume of iron, as determined by abnormal SWI-phase measurement, in the various SDGM structures, suggesting that iron deposition may precede structure-specific atrophy.

ATP inhibits Ins(1,4,5)P3-evoked Ca2+ release in smooth muscle via P2Y1 receptors

Adenosine 5′-triphosphate (ATP) mediates a variety of biological functions following nerve-evoked release, via activation of either G-protein-coupled P2Y- or ligand-gated P2X receptors. In smooth muscle, ATP, acting via P2Y receptors (P2YR), may act as an inhibitory neurotransmitter. The underlying mechanism(s) remain unclear, but have been proposed to involve the production of inositol 1,4,5-trisphosphate [Ins(1,4,5)P₃] by phospholipase C (PLC), to evoke Ca²⁺ release from the internal store and stimulation of Ca²⁺-activated potassium (K_Ca) channels to cause membrane hyperpolarization. This mechanism requires Ca²⁺ release from the store. However, in the present study, ATP evoked transient Ca²⁺ increases in only ~10% of voltage-clamped single smooth muscle cells. These results do not support activation of K_Ca as the major mechanism underlying inhibition of smooth muscle activity. Interestingly, ATP inhibited Ins(1,4,5)P₃-evoked Ca²⁺ release in cells that did not show a Ca²⁺ rise in response to purinergic activation. The reduction in Ins(1,4,5)P₃-evoked Ca²⁺ release was not mimicked by adenosine and therefore, cannot be explained by hydrolysis of ATP to adenosine. The reduction in Ins(1,4,5)P₃-evoked Ca²⁺ release was, however, also observed with its primary metabolite, ADP, and blocked by the P2Y₁R antagonist, MRS2179, and the G protein inhibitor, GDPβS, but not by PLC inhibition. The present study demonstrates a novel inhibitory effect of P2Y₁R activation on Ins(1,4,5)P₃-evoked Ca²⁺ release, such that purinergic stimulation acts to prevent Ins(1,4,5)P₃-mediated increases in excitability in smooth muscle and promote relaxation.

Voxel-wise magnetization transfer imaging study of effects of natalizumab and IFNβ-1a in multiple sclerosis

Objective:

To determine the effects of intravenous natalizumab and intramuscular interferon beta-1a (IFNβ-1a) on the volume of white-matter (WM) lesions and normal appearing brain tissue (NABT) undergoing voxel-wise (VW) increases in magnetization transfer ratio (MTR) suggestive of remyelination in patients with relapsing multiple sclerosis.

Methods:

This prospective, open-label, single-blinded study enrolled patients with relapsing–remitting multiple sclerosis (RRMS) and relapsing secondary progressive multiple sclerosis (RSPMS) as well as a group of age/sex-matched healthy controls ( n=22). Patients with multiple sclerosis were assigned to receive natalizumab monotherapy ( n=77; RRMS/RSPMS) or intramuscular IFNβ-1a ( n=26) as either monotherapy (RRMS) or combined with pulsed i.v. methylprednisolone, as needed (RSPMS). The primary endpoint was the two-year change in volume of NABT VWMTR, by quantifying the number of voxels that increased (suggesting remyelination) or decreased (suggesting demyelination) in their MTR value.

Results:

The volume of tissue undergoing increases in VWMTR was significantly larger in natalizumab compared with IFNβ-1a-treated patients (year 1: p=0.001 in NABT and p<0.006 in WM lesions; year 2: p=0.008 in NABT) and compared with healthy control subjects (year 1: p=0.05 and year 2: p=0.007 in NABT). The larger volume within NABT undergoing decreases in VWMTR was detected in multiple sclerosis patients compared with healthy controls ( p<0.001), and in the IFNβ-1a group compared with the natalizumab group (year 1: p=0.05; year 2: p=0.002). One patient on natalizumab died from progressive multifocal leukoencephalopathy eight months after completing the study.

Conclusion:

Natalizumab may promote remyelination and stabilize demyelination in lesions and NABT in relapsing multiple sclerosis, compared with intramuscular IFNβ-1a.

No association between conventional brain MR imaging and chronic cerebrospinal venous insufficiency in multiple sclerosis

BACKGROUND AND PURPOSE

CCSVI has been reported to occur at high frequency in MS. Its significance in relation to MR imaging parameters also needs to be determined, both in patients with MS and HCs. Therefore, this study determined the associations of CCSVI and conventional MR imaging outcomes in patients with MS and in HCs.

MATERIALS AND METHODS

T2, T1, and gadolinium lesion number, LV, and brain atrophy were assessed on 3T MR imaging in 301 subjects, of whom 162 had RRMS, 66 had secondary-progressive MS subtype, and 73 were HCs. CCSVI was assessed using extracranial and transcranial Doppler evaluation. The MR imaging measure differences were explored with 27 borderline cases for CCSVI, added to both the negative and positive CCSVI groups to assess sensitivity of the results of these cases.

RESULTS

No significant differences between subjects with and without CCSVI were found in any of the individual diagnostic subgroups or MS disease subtypes for lesion burden and atrophy measures, independently of the CCSVI classification criteria used, except for a trend for higher T2 lesion number (irrespective of how borderline cases were classified) and lower brain volume (when borderline cases were included in the positive group) in patients with RRMS with CCSVI. No CCSVI or MR imaging differences were found between 26 HCs with, or 47 without, a familial relationship.

CONCLUSIONS

CCSVI is not associated with more severe lesion burden or brain atrophy in patients with MS or in HCs.

Comparison of a 1.5T standard vs. 3T optimized protocols in multiple sclerosis patients

AIM

Use of postcontrast T1-weighted imaging (WI) is an important tool in diagnosing and predicting the course of multiple sclerosis (MS). Application of optimized imaging strategies has the potential to increase detection of magnetic resonance imaging (MRI) disease activity. This study investigated the superiority of the 3T optimized vs. the 1.5T standardized protocols in detecting gadolinium enhancing (GD-E) lesions in patients with MS.

METHODS

A standard protocol was defined as a 1.5T scan with a single-dose of Gd and a 5-minute scanning delay after injection. An optimized protocol was defined as a 3T MRI scan, using a triple dose of Gd, 20 min scan delay, and using an off-resonance saturated magnetization transfer pulse to reduce the background signal. Fourteen relapsing-remitting MS patients and 3 healthy controls (HC) were scanned with 1.5T standardized and a 3T optimized protocols in random order over 72 hours.

RESULTS

There were 47 Gd-E lesions in the MS patients on 3T optimized and 34 on 1.5T standard protocols, a 38.2% increase. There was a significant increase in Gd-enhanced lesion volume (LV) detected with the optimized protocol (179.6%, P<0.05), with 94.6% of the mean Gd-enhanced LV detected only on the 3T optimized protocol. No Gd-E lesions were detected in HC on either protocol.

CONCLUSION

The 3T optimized protocol is a useful technique for increasing sensitivity of MRI to detect Gd-E lesions.

Thromboprophylaxis for women undergoing caesarean section

Thromboprophylaxis for women undergoing caesarean section (CS) was introduced in the hospital in 1995. This study audited the use of tinzaparin prophylaxis in a nested cohort of women who screened negative for diabetes mellitus at 28 weeks gestation. All the women had their weight measured and BMI calculated at the first antenatal visit. Of the 284 women, 68 (24%) had a CS and all received tinzaparin. Of the 68, however, 94% received a dose lower than recommended. Compliance with prophylaxis was complete but compliance with the recommended dosage was suboptimal, which may result in venous thromboembolism after CS despite thromboprophylaxis.

Intra- and extraluminal structural and functional venous anomalies in multiple sclerosis, as evidenced by 2 noninvasive imaging techniques

BACKGROUND AND PURPOSE

Chronic cerebrospinal venous insufficiency (CCSVI) is a vascular condition characterized by anomalies of the main extracranial cerebrospinal venous routes that interfere with normal venous outflow. Research into CCSVI will determine its sensitivity and specificity for a diagnosis of MS, its prevalence in MS patients, and its clinical, MRI, and genetic correlates. Our aim was to investigate the prevalence and number of intra- and extraluminal structural and functional extracranial venous abnormalities by using DS and MRV, in patients with MS and HCs.

MATERIALS AND METHODS

One hundred fifty patients with MS, 104 (69.3%) with RR and 46 (30.7%) with a progressive MS course, and 63 age- and sex-matched HCs were scanned with 3T MR imaging by using TOF and TRICKS sequences (only patients with MS). All subjects underwent DS examination for intra- and extraluminal structural and functional abnormalities of the IJVs. Absent/pinpoint IJV flow morphology on MRV was considered an abnormal finding. Prominence of collateral extracranial veins was assessed with MRV.

RESULTS

Patients with MS had a significantly higher number of functional (P < .0001), total (P = .001), and intraluminal (P = .005) structural IJV DS abnormalities than HCs. There was a trend for more patients with MS with extraluminal IJV DS abnormalities (P = .023). No significant differences were found on the MRV IJV flow morphology scale between patients with MS and HCs. Patients with progressive MS showed more extraluminal IJV DS abnormalities (P = .01) and more MRV flow abnormalities on TOF (P = .006) and TRICKS (P = .01) than patients with nonprogressive MS. There was a trend for a higher number of collateral veins in patients with MS than in HCs (P = .016).

CONCLUSIONS

DS is more sensitive than MRV in detecting intraluminal structural and functional venous abnormalities in patients with MS compared with HCs, whereas MRV is more sensitive in showing collaterals.

Osteosarcoma: A rare cause of painful enlargement of the hallux

Malignant osseous and soft-tissue tumors of the foot are rare. We report a case of osteosarcoma in the proximal phalanx of the hallux in a 45-year-old man. In patients with foot-related symptoms, a high index of suspicion for pedal osteosarcoma is required. Delayed or inappropriate diagnosis may compromise limb-sparing surgery and survivorship.

Impact of colonoscopic screening in male and female Lynch syndrome carriers with an MSH2 mutation

The lifetime risk of developing colorectal cancer (CRC) in Lynch syndrome (LS) carriers is very high. To determine the impact of colonoscopic screening in 54 male and 98 female MSH2 mutation carriers, outcomes were compared with 94 males and 76 females who were not screened. CRC incidence and survival in the screened group were compared to that expected, derived from the non-screened group. To correct for survivor bias, controls were matched for age at entry into screening and also for gender. In males, median age to CRC was 58 years, whereas expected was 47 years (p = 0.000), and median survival was 66 years vs 62 years (p = 0.034). In screened females, median age to CRC was 79 years compared to 57 years in the non-screened group (p = 0.000), and median survival was 80 years compared with expected of 63 years (p = 0.001). Twenty percent of males and 7% of females developed an interval CRC within 2 years of previous colonoscopy. Although colonoscopic screening was associated with decreased CRC risk and better survival, CRCs continued to occur. CRC development may be further reduced by decreasing the screening interval to 1 year and improving quality of colonoscopy.

Ubiquitin-activating enzyme (UBA1) is required for sperm capacitation, acrosomal exocytosis and sperm-egg coat penetration during porcine fertilization

Protein ubiquitination is a stable, covalent post-translational modification that alters protein activity and/or targets proteins for proteolysis by the 26S proteasome. The E1-type ubiquitin-activating enzyme (UBA1) is responsible for ubiquitin activation, the initial step of ubiquitin-protein ligation. Proteasomal proteolysis of ubiquitinated spermatozoa and oocyte proteins occurs during mammalian fertilization, particularly at the site of sperm acrosome contact with oocyte zona pellucida. However, it is not clear whether the substrates are solely proteins ubiquitinated during gametogenesis or if de novo ubiquitination also occurs during fertilization supported by ubiquitin-activating and -conjugating enzymes present in the sperm acrosome. Along this line of inquiry, UBA1 was detected in boar sperm-acrosomal extracts by Western blotting (WB). Immunofluorescence revealed accumulation of UBA1 in the nuclei of spermatogonia, spermatocytes and spermatids, and in the acrosomal caps of round and elongating spermatids. Thiol ester assays utilizing biotinylated ubiquitin and isolated sperm acrosomes confirmed the enzymatic activity of the resident UBA1. A specific UBA1 inhibitor, PYR-41, altered the remodelling of the outer acrosomal membrane (OAM) during sperm capacitation, monitored using flow cytometry of fluorescein isothiocyanate-conjugated peanut agglutinin (FITC-PNA). Although viable and motile, the spermatozoa capacitated in the presence of PYR-41, showed significantly reduced fertilization rates during in vitro fertilization (IVF; p < 0.05). Similarly, the fertilization rate was lowered by the addition of PYR-41 directly into fertilization medium during IVF. In WB, high Mr bands, suggestive of protein ubiquitination, were detected in non-capacitated spermatozoa by antibodies against ubiquitin; WB with anti-phosphotyrosine antibodies and antibodies against acrosomal proteins SPINK2 (acrosin inhibitor) and AQN1 (spermadhesin) revealed that the capacitation-induced modification of those proteins was altered by PYR-41. In summary, it appears that de novo protein ubiquitination involving UBA1 contributes to sperm capacitation and acrosomal function during fertilization.

Pleuroperitoneal leak complicating peritoneal dialysis: a case series

Pressure related complications such as abdominal wall hernias occur with relative frequency in patients on peritoneal dialysis. Less frequently, a transudative pleural effusion containing dialysate can develop. This phenomenon appears to be due to increased intra-abdominal pressure in the setting of congenital or acquired diaphragmatic defects. We report three cases of pleuroperitoneal leak that occurred within a nine-month period at our institution. We review the literature on this topic, and discuss management options. The pleural effusion resolved in one patient following drainage of the peritoneum and a switch to haemodialysis. One patient required emergency thoracocentesis. The third patient developed a complex effusion requiring surgical intervention. The three cases highlight the variability of this condition in terms of timing, symptoms and management. The diagnosis of a pleuroperitoneal leak is an important one as it is managed very differently to most transudative pleural effusions seen in this patient population. Surgical repair may be necessary in those patients who wish to resume peritoneal dialysis, or in those patients with complex effusions. Pleuroperitoneal leak should be considered in the differential diagnosis of a pleural effusion, particularly a right-sided effusion, in a patient on peritoneal dialysis.

Maternal obesity and inpatient medication usage

What is already known about this subject •  Maternal obesity is associated with an increased use of healthcare resources including medication costs in an outpatient setting. What this study adds •  This study shows an increase in inpatient medication usage associated with maternal obesity. This is the case in the antenatal period but not in the peripartum period.

SUMMARY

Maternal obesity is associated with increased medical and obstetric complications. We compared the inpatient antenatal and peripartum medication usage in obese women to that in women in the normal body mass index (BMI) category. White European women with a singleton pregnancy were enrolled after a glucose tolerance test excluded diabetes mellitus at 28 weeks gestation. Weight and height were measured in the first trimester and BMI calculated. Records of medications administered were collated from patient drug charts. Of the 284 women studied, there were 97, 85 and 102 women in the normal, overweight and obese categories, respectively. Delivery details across the weight categories did not vary significantly and Caesarean section rates were 22.7, 22.4 and 26.5%, respectively. The length of hospital stay postpartum for each category was similar. The administration of antenatal medication showed a trend towards increasing usage with increasing BMI category with increases in analgesic and antibiotic use. There was no difference in peripartum medication usage. The study showed that maternal obesity was associated with an increased inpatient usage of medication in the antenatal period. This has implications for healthcare costs particularly if the prevalence of maternal obesity continues to increase.

The study of urban metabolism and its applications to urban planning and design

Following formative work in the 1970s, disappearance in the 1980s, and reemergence in the 1990s, a chronological review shows that the past decade has witnessed increasing interest in the study of urban metabolism. The review finds that there are two related, non-conflicting, schools of urban metabolism: one following Odum describes metabolism in terms of energy equivalents; while the second more broadly expresses a city's flows of water, materials and nutrients in terms of mass fluxes. Four example applications of urban metabolism studies are discussed: urban sustainability indicators; inputs to urban greenhouse gas emissions calculation; mathematical models of urban metabolism for policy analysis; and as a basis for sustainable urban design. Future directions include fuller integration of social, health and economic indicators into the urban metabolism framework, while tackling the great sustainability challenge of reconstructing cities.