Enhanced diffuse optical tomographic reconstruction using concurrent ultrasound information.

Multimodal imaging is an active branch of research as it has the potential to improve common medical imaging techniques. Diffuse optical tomography (DOT) is an example of a low resolution, functional imaging modality that typically has very low resolution due to the ill-posedness of its underlying inverse problem. Combining the functional information of DOT with a high resolution structural imaging modality has been studied widely. In particular, the combination of DOT with ultrasound (US) could serve as a useful tool for clinicians for the formulation of accurate diagnosis of breast lesions. In this paper, we propose a novel method for US-guided DOT reconstruction using a portable time-domain measurement system. B-mode US imaging is used to retrieve morphological information on the probed tissues by means of a semi-automatical segmentation procedure based on active contour fitting. A two-dimensional to three-dimensional extrapolation procedure, based on the concept of distance transform, is then applied to generate a three-dimensional edge-weighting prior for the regularization of DOT. The reconstruction procedure has been tested on experimental data obtained on specifically designed dual-modality silicon phantoms. Results show a substantial quantification improvement upon the application of the implemented technique. This article is part of the theme issue 'Synergistic tomographic image reconstruction: part 2'.

Polarization-state-resolved high-harmonic spectroscopy of solids.

Attosecond metrology sensitive to sub-optical-cycle electronic and structural dynamics is opening up new avenues for ultrafast spectroscopy of condensed matter. Using intense lightwaves to precisely control the fast carrier dynamics in crystals holds great promise for next-generation petahertz electronics and devices. The carrier dynamics can produce high-order harmonics of the driving field extending up into the extreme-ultraviolet region. Here, we introduce polarization-state-resolved high-harmonic spectroscopy of solids, which provides deeper insights into both electronic and structural sub-cycle dynamics. Performing high-harmonic generation measurements from silicon and quartz, we demonstrate that the polarization states of the harmonics are not only determined by crystal symmetries, but can be dynamically controlled, as a consequence of the intertwined interband and intraband electronic dynamics. We exploit this symmetry-dynamics duality to efficiently generate coherent circularly polarized harmonics from elliptically polarized pulses. Our experimental results are supported by ab-initio simulations, providing evidence for the microscopic origin of the phenomenon.

Comparison of genioglossus muscle activity and efficiency of dexmedetomidine or propofol during drug-induced sleep endoscopy in patients with obstructive sleep apnea/hypopnea syndrome.

OBJECTIVE: The purpose of this study is to evaluate the haemodynamic and respiratory effects of dexmedetomidine vs. propofol in patients with OSAHS during the drug-induced sleep endoscopy (DISE), and analyze simultaneously the electromyography of genioglossus muscle. PATIENTS AND METHODS: We conducted a study on 50 patients with OSAHS; patients were subjected to DISE with simultaneous polygraphic cardiorespiratory measurement and electromyography of genioglossus muscle. Patients undergoing DISE were divided in two groups: in Group A (19 M; 8 W) was administered propofol TCI and in Group B (16 M; 7 W) was administered dexmedetomidine TCI. RESULTS: In Group A, a mean minimal SpO2 decreasing of 3.7% (p=0.000) and a mean SpO2 decreasing of 1.6% (p 0.001) was noticed, while there was an increase in BP20 of 14.8% (p=0.000) and HR20 of 11.1% (p=0.000). In Group B, it was showed a decreasing of mean minimal SpO2 and mean SpO2 values, about 1.8% (p=0.000) and 1.1% (p 0.009) respectively, while there was an increase of BP20 and HR20, about 8.7% (p=0.000) and 8% (p 0.002), respectively. Despite EMG activity comparing spontaneous sleep with propofol-DISE, there is a statistically significative change for the amplitude (p=0.040) and an increase of 7.01% for the area under the curve (AUC). Comparing spontaneous sleep with dexmedetomidine-DISE induced one, there is only an increase of 25.87% in the AUC. CONCLUSIONS: A greater worsening of the cardio-respiratory basal values was noted after sleep induction with Propofol and same results were obtained confronting EMG of genioglossus muscle data.

Blink reflex recovery cycle to differentiate progressive supranuclear palsy from corticobasal syndrome.

BACKGROUND AND PURPOSE: Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) may share similar clinical findings and tests to distinguish between the two disorders could be useful. We evaluated the blink reflex and R2 blink reflex recovery cycle (R2BRRC), determining diagnostic sensitivity, specificity and positive and negative predictive value of R2BRRC in differentiating patients with PSP from those with CBS. METHODS: This was a prospective data collection study investigating blink reflex and R2BRRC at interstimulus intervals (ISIs) of 100, 150, 200, 300, 400, 500 and 750 ms in 12 patients with PSP, eight patients with CBS and 10 controls. RESULTS: Patients with PSP have earlier recruitment of R2BRRC as compared with patients with CBS (ISI: 100 ms, P = 0.002; 150 ms, P < 0.001; 200 ms, P < 0.001; 300 ms, P = 0.02) and controls (ISI: 100 ms, P < 0.001; 150 ms, P < 0.001; 200 ms, P < 0.001; 300 ms, P = 0.004). The presence of an early recovery of the R2 differentiated PSP from CBS with a specificity and sensitivity of 87.5% and 91.7%, respectively. CONCLUSIONS: The R2BRRC curve might be considered to be a useful tool in differentiating patients with PSP from those with CBS.

Early postnatal genistein administration permanently affects nitrergic and vasopressinergic systems in a sex-specific way.

Genistein (GEN) is a natural xenoestrogen (isoflavonoid) that may interfere with the development of estrogen-sensitive neural circuits. Due to the large and increasing use of soy-based formulas for babies (characterized by a high content of GEN), there are some concerns that this could result in an impairment of some estrogen-sensitive neural circuits and behaviors. In a previous study, we demonstrated that its oral administration to female mice during late pregnancy and early lactation induced a significant decrease of nitric oxide synthase-positive cells in the amygdala of their male offspring. In the present study, we have used a different experimental protocol mimicking, in mice, the direct precocious exposure to GEN. Mice pups of both sexes were fed either with oil, estradiol or GEN from birth to postnatal day 8. Nitric oxide synthase and vasopressin neural systems were analyzed in adult mice. Interestingly, we observed that GEN effect was time specific (when compared to our previous study), sex specific, and not always comparable to the effects of estradiol. This last observation suggests that GEN may act through different intracellular pathways. Present results indicate that the effect of natural xenoestrogens on the development of the brain may be highly variable: a plethora of neuronal circuits may be affected depending on sex, time of exposure, intracellular pathway involved, and target cells. This raises concern on the possible long-term effects of the use of soy-based formulas for babies, which may be currently underestimated.

Obsessive compulsive personality disorder in Progressive Supranuclear Palsy, Multiple System Atrophy and Essential Tremor.

INTRODUCTION: aim of the study was to evaluate the presence of the Obsessive Compulsive Personality Disorder (OCPeD) in Multiple System Atrophy (MSA), Progressive Supranuclear Palsy (PSP) and Essential Tremor (ET) and in a group of healthy subjects. METHODS: patients affected by MSA, PSP and ET diagnosed according to currently accepted diagnostic criteria and a group of healthy controls were enrolled in the study. Patients with cognitive impairment were excluded from the study. The Structured Clinical Interview for Personality Disorders-II (SCID-II) has been performed to evaluate the presence of personality disorders (PeDs). The diagnosis of OCPeD was confirmed by a psychiatric interview. RESULTS: fifteen MSA patients (8 men and 7 women; aged 62.9 ± 7.6 years), 14 PSP patients (8 men and 6 women; aged 69.8 ± 4.4 years), 16 ET patients (10 men and 6 women; aged 70.4 ± 6.4 years) and 20 healthy subjects (10 men and 10 women; aged 65.5 ± 6.0 years) were enrolled. OCPeD was recorded in 5 (35.7%) PSP patients, 2 (13.3%) MSA patients, 2 (12.5%) ET patient and 2 (10%) controls. CONCLUSION: a low frequency of OCPeD, close to those recorded in healthy subjects, was recorded in both MSA and ET patients. Conversely an higher frequency of OCPeD, similar to PD was found among PSP patients, supporting the possibility of an impairment of common basal ganglia network possibly involving the orbito-frontal circuits.

Validation of the UPDRS section IV for detection of motor fluctuations in Parkinson's disease.

INTRODUCTION: The UPDRS-IV represents the most common screening tool to assess motor fluctuations in patients with PD despite the lack of a clinimetric validation. OBJECTIVES: We evaluated sensitivity and specificity of UPDRS-IV using a 12-h waking-day motor assessment as the gold standard. METHODS: We consecutively enrolled PD patients who underwent a 12-h waking-day motor assessment in the study. Patients were clinically evaluated every 2 h for 12 h using the UPDRS-III. Motor scores were reported as a line graph and six blinded raters classified patients as having or not having motor fluctuations. The UPDRS-IV was used in order to assess the presence of predictable and unpredictable motor fluctuations according to items 36-38. RESULTS: Sixty two PD patients were enrolled in the study. According to the raters' evaluations, 39 (62.9%) were classified as having motor fluctuations, while according to the UPDRS-IV 47 (75.8%) presented a motor fluctuation giving a sensitivity of 87.2% (95%CI 72.6-95.7) and a specificity of 43.5% (95%CI 23.2-65.5). CONCLUSION: Our study results confirm the high level of sensitivity with a lower level of specificity of UPDRS-IV to screen motor fluctuations in PD patients.

Tremor pattern differentiates drug-induced resting tremor from Parkinson disease.

OBJECTIVE: DAT-SPECT, is a well-established procedure for distinguishing drug-induced parkinsonism from Parkinson's disease (PD). We investigated the usefulness of blink reflex recovery cycle (BRrc) and of electromyographic parameters of resting tremor for the differentiation of patients with drug-induced parkinsonism with resting tremor (rDIP) from those with resting tremor due to PD. METHODS: This was a cross-sectional study. In 16 patients with rDIP and 18 patients with PD we analysed electrophysiological parameters (amplitude, duration, burst and pattern) of resting tremor. BRrc at interstimulus intervals (ISI) of 100, 150, 200, 300, 400, 500 and 750 msec was also analysed in patients with rDIP, patients with PD and healthy controls. All patients and controls underwent DAT-SPECT. RESULTS: Rest tremor amplitude was higher in PD patients than in rDIP patients (p < 0.001), while frequency and burst duration were higher in rDIP than in PD (p < 0.001, p < 0.003, respectively). Resting tremor showed a synchronous pattern in all patients with rDIP, whereas it had an alternating pattern in all PD patients (p < 0.001). DAT-SPECT was normal in rDIP patients while it was markedly abnormal in patients with PD. CONCLUSIONS: In the absence of DAT-SPECT, the pattern of resting tremor can be considered a useful investigation for differentiating rDIP from PD.

Looks can be deceiving: three cases of neurological diseases mimicking Guillain-Barrè syndrome.

Guillain-Barrè syndrome (GBS) is an acute, paralyzing, inflammatory peripheral nerve disease, featured by monophasic disease course, symmetrical limb weakness and areflexia. Several pathologies can mimic the clinical presentation of GBS, making hard the differential diagnosis for patients complaining of acute flaccid paralysis. In this paper we describe three cases of different neurological diseases presenting with acute motor symptoms mimicking GBS, reviewing the relevant literature on misdiagnosis of GBS.

Double-level cervical total disc replacement for adjacent segment disease: is it a useful treatment? Description of late onset heterotopic ossification and review of the literature.

We report a rare case of double-level adjacent segment disease (ASD), occurring ten years later an anterior cervical discectomy (ACD) without fusion, treated by cervical arthroplasty, highlighting the outcome at long-term follow-up and focusing on heterotopic ossification. In 1995 a 25-year-old man satisfactorily underwent ACD at C4/C5. At that time MRI also showed signs of degenerative disc disease (DDD) at C3/C4 and C5/C6. Ten years later, a new MRI scan showed a large C3/C4 and a smaller C5/C6 soft disc hernia together with spondylotic changes at the level above and below the site of the first surgery. At C4/C5 imaging revealed a kyphotic stable "pseudoarthrosis" with anterior bridging osteophyte. The patient underwent double-level arthroplasty with ProDisc-C. Clinical and radiological outcome was satisfactory. 3 and 5 years after surgery, X-rays and CT scan documented the progressive development of heterotopic ossification, with gradual reduction of range of motion. A late onset heterotopic ossification can neutralize the theoretical advantages of cervical arthroplasty, which should be considered an effective surgical option only in selected cases. ACDF and restoration of normal lordosis can be a viable alternative in cervical revision surgery, as motion preservation can not be always mantained for a long time.

Anterior, extracanalar, cervical spine osteochondroma associated with DISH: description of a very rare tumor causing bilateral vocal cord paralysis, laryngeal compression and dysphagia. Case report and review of the literature.

INTRODUCTION: Osteochondromas are common benign bone tumors, rarely involving the spine. BACKGROUND: Osteochondroma account for about 35% of bone benign tumors and 9% of all bone tumors. Spinal involvement is described in 1%-4% of cases and their origin from the anterior surface of cervical vertebral bodies is exceedingly rare. AIM: We describe the rare case of an osteochondroma arising from the anterior surface of the C4 and C5 vertebral bodies, and not involving the spinal canal, in a 68-year-old male patient suffering from Diffuse Idiopathic Skeletal Hyperostosis (DISH). MATERIALS AND METHODS: The patient presented with acute onset of respiratory distress due to laryngeal compression exerted by the lesion, dysphagia and paralysis of left vocal cord. Imaging revealed the unusual lesion compressing and dislocating the air ways. An anterior approach to cervical spine was performed to remove the tumor. RESULTS: Postoperatively, the patient sustained a progressive improvement of respiratory function and recovery of the vocal cord paralysis. DISCUSSION: We believe that this case holds some interesting peculiarities: firstly, the anterior location of a cervical osteochondroma could be considered exceptional; yet, the resulting clinical picture should be remembered for differential diagnosis. Secondly, we hypothesized a possible correlation between the tumorigenesis of osteochondroma and the co-existence of DISH. Indeed, the abnormal bone turnover in cervical segments due to DISH could explain the unusual occurrence of osteochondromas in adult age. CONCLUSIONS: The occurrence of an osteochondroma should be considered in patients suffering from DISH and harbouring large osteophytes.

[A polymorphism study of the DNA extracted from dental tissues]. / Studio di polimorfismi del DNA estratto da tessuti dentari.

Often teeth are the only items which can be used for personal identification in forensic medicine. In the present work we describe a method to extract and amplify DNA from dental elements ranging from 2 weeks to 5 year from the avulsion. PCR (polymerase chain reaction) was used to amplify VNTR sequences; the alleles products were electrophoresed, visualized by traditional methods and compared to the amplified products obtained from the matching blood sample. Our results give a new and powerful investigative tool for personal identification in the field of forensic odontostomatology, since such a procedure can be successfully applied both to recent and to ancient teeth.

[DNA extraction from hard dental tissues]. / Estrazione di DNA dai tessuti duri del dente.

Two different standard ways of DNA extraction (salting out and phenol-chloroform methods) were assayed in order to recovery nucleic acids from dental tissues. The DNA extracted was tested for purity by means of transverse alternating field electrophoresis (TAFE) using Saccharomyces cerevisiae chromosomes as markers. Both extraction methods give similar qualitative and quantitative results being a DNA yield from hard dental tissues approximately 30% of those extracted from the whole tooth. Our results indicate salting out as a preferable method due to its rapidity and usefulness.

Influence of different counterions on the fluorescent probe-DNA complex.

Studies carried out on both linear and covalently closed DNA have clearly revealed at least two different types of probe-DNA complexes depending on the different experimental procedure adopted, and two main types of binding of the probe have been clearly established and referred to as intercalative and external binding. In order to investigate the influences of the different counterions on the stability of the probe-DNA complex, a set of static fluorimetric measurements were performed in a wide range of concentrations (1 mM to 2 M) of different alkaline-earth chlorides. At low salt concentrations (in the range of millimolar values) no detectable fluorescence intensity changes were evidenced by the use of alkaline salts, but a marked decrease was detected by using alkaline-earth salts. The present work investigates moreover the role played by the different salt, in first place Calcium salts, on the stability of ethidium-DNA complex, by the use of the static fluorimetric titration procedure which is able to discriminate between the two strong and weak binding sites on DNA. Our experimental results have been interpreted in terms of a peculiar Calcium-DNA interaction, involving not only the electrostatic charges of phosphate moiety but also the aromatic rings of the bases, i.e., the intercalation sites on double helix DNA.