Mercury Strain-Gauge Plethysmography Venous Mode: Non-Invasive Technique of Choice in Vascular Pathology

Mercury strain-gauge plethysmography venous mode is a non-invasive technique for exploration of the haemodynamics of the extremities. The plethysmographic parameters used are: (1) the venous inflow (in ml/100 ml/min); (2) the venous outflow (in ml/100 ml/min); (3) the venous capacity in ml/100ml; (4) the venous distensibility index in ml/100 ml/ mmHg; and (5) the venous pressure measured by ‘hysteresis curve’. This method permits us to analyse the venous haemodynamics of both extremities simultaneously (the normal limb serving as the control), to obtain a precise diagnosis and to appreciate the efficacy of treatment at follow-up.

The aetiology of the swollen limb can be precisely identified in 95% of the studied cases: oedema in superficial venous insufficiency, oedema in the deep venous insufficiency, oedema of inflammatory origin, oedema in the arterial insufficiency, oedema of cardiac origin, lymphoedema.

During the last 3 years, we have followed up 580 patients with this method.

Comparison of hip geometry, strength, and estimated fracture risk in women with anorexia nervosa and overweight/obese women

CONTEXT

Data suggest that anorexia nervosa (AN) and obesity are complicated by elevated fracture risk, but skeletal site-specific data are lacking. Traditional bone mineral density (BMD) measurements are unsatisfactory at both weight extremes. Hip structural analysis (HSA) uses dual-energy X-ray absorptiometry data to estimate hip geometry and femoral strength. Factor of risk (φ) is the ratio of force applied to the hip from a fall with respect to femoral strength; higher values indicate higher hip fracture risk.

OBJECTIVE

The objective of the study was to investigate hip fracture risk in AN and overweight/obese women.

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted at a Clinical Research Center.

PATIENTS

PATIENTS included 368 women (aged 19-45 y): 246 AN, 53 overweight/obese, and 69 lean controls.

MAIN OUTCOME MEASURES

HSA-derived femoral geometry, peak factor of risk for hip fracture, and factor of risk for hip fracture attenuated by trochanteric soft tissue (φ(attenuated)) were measured.

RESULTS

Most HSA-derived parameters were impaired in AN and superior in obese/overweight women vs controls at the narrow neck, intertrochanteric, and femoral shaft (P ≤ .03). The φ(attenuated) was highest in AN and lowest in overweight/obese women (P < .0001). Lean mass was associated with superior, and duration of amenorrhea with inferior, HSA-derived parameters and φ(attenuated) (P < .05). Mean φ(attenuated) (P = .036), but not femoral neck BMD or HSA-estimated geometry, was impaired in women who had experienced fragility fractures.

CONCLUSIONS

Femoral geometry by HSA, hip BMD, and factor of risk for hip fracture attenuated by soft tissue are impaired in AN and superior in obesity, suggesting higher and lower hip fracture risk, respectively. Only attenuated factor of risk was associated with fragility fracture prevalence, suggesting that variability in soft tissue padding may help explain site-specific fracture risk not captured by BMD.

Tauopathy PET and amyloid PET in the diagnosis of chronic traumatic encephalopathies: studies of a retired NFL player and of a man with FTD and a severe head injury

Single, severe traumatic brain injury (TBI) which elevates CNS amyloid, increases the risk of Alzheimer's disease (AD); while repetitive concussive and subconcussive events as observed in athletes and military personnel, may increase the risk of chronic traumatic encephalopathy (CTE). We describe two clinical cases, one with a history of multiple concussions during a career in the National Football League (NFL) and the second with frontotemporal dementia and a single, severe TBI. Both patients presented with cognitive decline and underwent [(18)F]-Florbetapir positron emission tomography (PET) imaging for amyloid plaques; the retired NFL player also underwent [(18)F]-T807 PET imaging, a new ligand binding to tau, the main constituent of neurofibrillary tangles (NFT). Case 1, the former NFL player, was 71 years old when he presented with memory impairment and a clinical profile highly similar to AD. [(18)F]-Florbetapir PET imaging was negative, essentially excluding AD as a diagnosis. CTE was suspected clinically, and [(18)F]-T807 PET imaging revealed striatal and nigral [(18)F]-T807 retention consistent with the presence of tauopathy. Case 2 was a 56-year-old man with personality changes and cognitive decline who had sustained a fall complicated by a subdural hematoma. At 1 year post injury, [(18)F]-Florbetapir PET imaging was negative for an AD pattern of amyloid accumulation in this subject. Focal [(18)F]-Florbetapir retention was noted at the site of impact. In case 1, amyloid imaging provided improved diagnostic accuracy where standard clinical and laboratory criteria were inadequate. In that same case, tau imaging with [(18)F]-T807 revealed a subcortical tauopathy that we interpret as a novel form of CTE with a distribution of tauopathy that mimics, to some extent, that of progressive supranuclear palsy (PSP), despite a clinical presentation of amnesia without any movement disorder complaints or signs. A key distinguishing feature is that our patient presented with hippocampal involvement, which is more frequently seen in CTE than in PSP. In case 2, focal [(18)F]-Florbetapir retention at the site of injury in an otherwise negative scan suggests focal amyloid aggregation. In each of these complex cases, a combination of [(18)F]-fluorodeoxyglucose, [(18)F]-Florbetapir and/or [(18)F]-T807 PET molecular imaging improved the accuracy of diagnosis and prevented inappropriate interventions.

Pharmacological approach to diabetic macular edema

Diabetic macular edema (DME) is a highly prevalent cause of vision loss and has a remarkable impact on public health, and on the quality of life of diabetic patients. Even though laser photocoagulation has been the standard of care for decades, a substantial group of patients are unresponsive and fail to improve after laser treatment. Recently, new pharmacological approaches based on the use of intravitreal drugs, such as corticosteroids and anti-vascular endothelial growth factor, have revolutionized the treatment of DME. The use of intravitreal drugs is supported by the improvement in visual acuity reported by several clinical trials and can limit the potentially destructive effects of the laser treatment. Encouraging results also emerged from studies evaluating the use of a combination therapy, or the association of intravitreal drugs and laser treatment. This review aims at providing a brief synopsis of the main investigations regarding the current pharmacological approach to DME.

Proposed Rabi-Kondo correlated state in a laser-driven semiconductor quantum dot

Spin exchange between a single-electron charged quantum dot and itinerant electrons leads to an emergence of Kondo correlations. When the quantum dot is driven resonantly by weak laser light, the resulting emission spectrum allows for a direct probe of these correlations. In the opposite limit of vanishing exchange interaction and strong laser drive, the quantum dot exhibits coherent oscillations between the single-spin and optically excited states. Here, we show that the interplay between strong exchange and nonperturbative laser coupling leads to the formation of a new nonequilibrium quantum-correlated state, characterized by the emergence of a laser-induced secondary spin screening cloud, and examine the implications for the emission spectrum.

Hip structural analysis in adolescent and young adult oligoamenorrheic and eumenorrheic athletes and nonathletes

CONTEXT

Stress fractures are common in endurance athletes. Whereas studies have described distal tibia bone structure in athletes, there are few data regarding hip geometric parameters. Hip structural analysis (HSA) using dual-energy x-ray absorptiometry is a validated technique to assess hip bone structure.

OBJECTIVES

The purpose of this study was to compare hip geometry in young oligoamenorrheic athletes (AAs), eumenorrheic athletes (EAs), and nonathletes using HSA. We hypothesized that AAs would have impaired bone structure compared with that of EAs.

DESIGN

This was a cross-sectional study.

SETTING

The setting was a clinical research center.

SUBJECTS

We enrolled 55 AAs, 24 EAs, and 23 nonathletes of normal weight who were 14 to 22 years old. Athletes ran ≥20 miles/wk or were engaged in weight-bearing sports for ≥4 hours/wk.

MAIN OUTCOME MEASURES

Dual-energy x-ray absorptiometry was used for HSA and hip areal bone mineral density (aBMD).

RESULTS

Hip aBMD Z-scores were lower in AAs and in nonathletes than in EAs (P = .002). A larger proportion of AAs than EAs and nonathletes had hip Z-scores <-1 (30.9, 4.2, 17.4%, P = .01). At the narrow neck, trochanteric region, and femoral shaft, subperiosteal width, cross-sectional moment of inertia, and section modulus were higher in EAs than in nonathletes; values in AAs did not differ from those of nonathletes. Cross-sectional area was lower in AAs and in nonathletes than in EAs. Groups did not differ for cortical thickness or buckling ratio. Group differences were lost after adjustment for lean mass but not aBMD.

CONCLUSIONS

In an eugonadal state, athletic activity confers benefits for hip structure independent of aBMD. This advantage is lost in AAs, who do not differ from nonathletes for most parameters and fare worse than EAs for cross-sectional area.

Long-term evaluation of patients treated with dexamethasone intravitreal implant for macular edema due to retinal vein occlusion

PURPOSE

To evaluate the long-term visual prognosis and complications of patients who received intravitreal Ozurdex injections for the treatment of macular edema (ME) due to retinal vein occlusion (RVO).

METHODS

A total of 17 patients who received Ozurdex injections in our institution as part of the GENEVA study were recalled for examination. Recorded parameters included final visual acuity (VA), final retinal thickness by optical coherence tomography, persistence of ME, and the occurrence of any complications.

RESULTS

Mean follow-up time was 50.5 months. Patients with branch RVO (BRVO) had a more favorable prognosis than central RVO (CRVO), and their mean VA had improved significantly, whereas the mean VA for the patients with CRVO did not improve significantly. Retinal thickness had reduced significantly in the whole group and in each subgroup separately. Complications included 10 patients with cataract progression, 1 with elevated intraocular pressure, and 1 with neovascularization and vitreous hemorrhage.

CONCLUSIONS

This is the first reported long-term evaluation of patients treated with Ozurdex. Our results indicate that it has favorable long-term safety profile, and may have a beneficial effect on the visual prognosis in BRVO even in the absence of continuous treatment. Further research is required to establish the optimal retreatment schedule for Ozurdex.