Brain Hemisphere Dissimilarity, a Self-Supervised Learning Approach for alpha-synucleinopathies prediction with FDG PET

Idiopathic Rem sleep Behavior Disorder (iRBD) is a significant biomarker for the development of alpha-synucleinopathies, such as Parkinson's disease (PD) or Dementia with Lewy bodies (DLB). Methods to identify patterns in iRBD patients can help in the prediction of the future conversion to these diseases during the long prodromal phase when symptoms are non-specific. These methods are essential for disease management and clinical trial recruitment. Brain PET scans with 18F-FDG PET radiotracers have recently shown promise, however, the scarcity of longitudinal data and PD/DLB conversion information makes the use of representation learning approaches such as deep convolutional networks not feasible if trained in a supervised manner. In this work, we propose a self-supervised learning strategy to learn features by comparing the brain hemispheres of iRBD non-convertor subjects, which allows for pre-training a convolutional network on a small data regimen. We introduce a loss function called hemisphere dissimilarity loss (HDL), which extends the Barlow Twins loss, that promotes the creation of invariant and non-redundant features for brain hemispheres of the same subject, and the opposite for hemispheres of different subjects. This loss enables the pre-training of a network without any information about the disease, which is then used to generate full brain feature vectors that are fine-tuned to two downstream tasks: follow-up conversion, and the type of conversion (PD or DLB) using baseline 18F-FDG PET. In our results, we find that the HDL outperforms the variational autoencoder with different forms of inputs.

Management of systemic prostate cancer: current algorithm from castration sensitive to castration resistant setting

In recent years, the advanced knowledge of clinical, biological and molecular features of prostate cancer have led to the introduction of new drugs and have allowed the relocation of old drugs in different settings. In this way, the new concepts of systemic disease arise: high risk or high volume vs. low risk and low volume disease castration sensitive prostate cancer (CSPC), diversifying the use of previously approved drugs (CRPC) and opening new scenarios for sequence therapy. The aim of this review is to integrate new developments into the medical management of systemic prostate cancer.

Advanced/metastatic bladder cancer: current status and future directions

In 2015 bladder cancer was the fourth most frequent malignancy and the eighth cause of death for cancer. At diagnosis, about 30% of bladder cancer (BC) patients present a muscle-invasive bladder cancer (MIBC) and 5% a metastatic bladder carcinoma (MBC). For fit MBC patients, combination chemotherapy (CC) is the standard of care for first-line treatment. CC includes both the treatment with methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC) either the classical or the dose-dense MVAC regimen, and the doublet therapy with cisplatin and gemcitabine (CG). Median progression free survival (PFS) was 7 months and median overall survival (OS) was 15 months. The present review provides an update on the management of MBC, with focus on target therapies, immune checkpoint inhibition, looking for prognostic and predictive factors.

Penile cancer: prognostic and predictive factors in clinical decision-making

Penile cancer (PC) is a typical tumor of non-industrialized countries. The incidence is 20-30 times higher in Africa and South America, considering the elevated prevalence of sexually transmitted diseases. Histologically, PC includes squamous cell carcinoma (SCPC), the most frequent, and nonsquamous carcinoma (NSCPC). Early diagnosis is the goal, whereas later diagnosis relates to poor functional outcomes and worse prognosis. The 5-year survival rate is 85% for patients with histologically regional negative lymph nodes, compared to 29%-40% for those with histologically regional positive lymph nodes. To date no new drugs are approved, and there are few new data about molecular mechanisms underlying tumorigenesis. The SCPC remains a rare tumor and the current therapeutic algorithm is based principally on retrospective analysis and less on prospective trials. In this review article, biomarkers of prognosis and efficacy of current treatments are summarized with a focus on those that have the potential to affect treatment decision-making in SCPC.

Preliminary evidence that vortioxetine may improve sleep quality in depressed patients with insomnia: a retrospective questionnaire analysis

Insomnia is a frequent symptom in depressed patients. It can present with difficulty in initiating and/or maintaining sleep. We retrospectively evaluated a group of 15 patients affected by major depressive disorder and complaining of insomnia, who started vortioxetine (VOR) treatment for their depressive symptoms. The following questionnaires were captured at baseline and follow-up: Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Beck Depression Inventory. Pittsburgh Sleep Quality Index total score significantly decreased between follow-up and baseline (P < 0.01), and in several subitems related to sleep quality and continuity. Moreover, Epworth Sleepiness Scale decreased between follow-up and baseline (P < 0.01). Finally, Beck Depression Inventory reduction was also evident between follow-up and baseline (P < 0.01). This retrospective analysis showing the significant effect of VOR on both depressive symptoms and insomnia in patients showing comorbid major depressive disorder and insomnia invites further research in order to confirm this preliminary evidence. We hypothesize that the VOR mechanism of action may explain the improvement of subjective sleep, other than depressive symptoms.

Subthalamic nucleus deep brain stimulation on motor-symptoms of Parkinson's disease: Focus on neurochemistry

Deep brain stimulation (DBS) has become a standard therapy for Parkinson's disease (PD) and it is also currently under investigation for other neurological and psychiatric disorders. Although many scientific, clinical and ethical issues are still unresolved, DBS delivered into the subthalamic nucleus (STN) has improved the quality of life of several thousands of patients. The mechanisms underlying STN-DBS have been debated extensively in several reviews; less investigated are the biochemical consequences, which are still under scrutiny. Crucial and only partially understood, for instance, are the complex interplays occurring between STN-DBS and levodopa (LD)-centred therapy in the post-surgery follow-up. The main goal of this review is to address the question of whether an improved motor control, based on STN-DBS therapy, is also achieved through the additional modulation of other neurotransmitters, such as noradrenaline (NA) and serotonin (5-HT). A critical issue is to understand not only acute DBS-mediated effects, but also chronic changes, such as those involving cyclic nucleotides, capable of modulating circuit plasticity. The present article will discuss the neurochemical changes promoted by STN-DBS and will document the main results obtained in microdialysis studies. Furthermore, we will also examine the preliminary achievements of voltammetry applied to humans, and discuss new hypothetical investigational routes, taking into account novel players such as glia, or subcortical regions such as the pedunculopontine (PPN) area. Our further understanding of specific changes in brain chemistry promoted by STN-DBS would further disseminate its utilisation, at any stage of disease, avoiding an irreversible lesioning approach.

CSF lactate levels, τ proteins, cognitive decline: a dynamic relationship in Alzheimer's disease

OBJECTIVES

To investigate, in patients with Alzheimer's Disease (AD), the possible interplay linking alteration of neuronal energy metabolism, as measured via cerebrospinal fluid (CSF) lactate concentration, to severity of AD neurodegenerative processes and impairment of cognitive abilities.

METHODS

In this study we measured and correlated CSF lactate concentrations, AD biomarker levels (τ-proteins and β-amyloid) and Mini-Mental State Examination (MMSE) score in a population of drug-naïve patients with AD ranging from mild (MMSE≥21/30) to moderate-severe (MMSE<21/30) cognitive decline. They were compared to healthy controls and patients with vascular dementia (VaD).

RESULTS

Patients with AD (n=145) showed a significant increase of CSF lactate concentration compared to controls (n=80) and patients with VaD (n=44), which was higher in mild (n=67) than in patients with moderate-severe AD (n=78). Moreover, we found, in either the whole AD population or both subgroups, a CSF profile in which higher CSF levels of t-τ and p-τ proteins corresponded to lower concentrations of lactate.

CONCLUSIONS

We verified the occurrence of high CSF lactate levels in patients with AD, which may be ascribed to mitochondria impairment. Hypothesising that τ proteins may exert a detrimental effect on the entire cellular energy metabolism, the negative correlation found between lactate and τ-protein levels may allow speculation that τ toxicity, already demonstrated to have affected mitochondria, could also impair glycolytic metabolism with a less evident increase of lactate levels in more severe AD. Thus, we suggest a dynamic relationship between neuronal energy metabolism, τ proteins and cognitive decline in AD and propose the clinical potential of assessing CSF lactate levels in patients with AD to better define the neuronal brain metabolism damage.

Estimation of liver iron concentration by dual energy CT images: influence of X-ray energy on sensitivity

In hemochromatosis an abnormal accumulation of iron is present in parenchymal organs and especially in liver. Among the several techniques employed to diagnose the iron overload, magnetic resonance imaging (MRI) and Computed Tomography (CT) are the most promising non-invasive ones. MRI is largely used but shows limitation including an overestimation of iron and inability to quantify iron at very high concentrations. Therefore, some research groups are focusing on the estimation of iron concentration by CT images. Single X-ray CTs are not able to accurately perform this task in case of the presence of confounding factors (e.g., fat). A potential solution to overcome this concern is the employment of Dual-Energy CT (DECT). The aim of this work is to investigate influence of the kVp and mAs on CT number sensitivity to iron concentration. A phantom with test tubes filled with homogenized porcine liver at different iron concentrations, has been scanned with DECT at different mAs. The images have been analyzed using an ad-hoc developed algorithm which allows minimizing the influence of air bubbles present in the homogenized. Data show that the sensitivity is strongly influenced by kVp (its value almost halves from 80 kVp to 140 kVp; e.g. 0.41 g·μmol(-1) and 0.19 g·μmol(-1) at 80 kVp/120 mAs and 140 kVp/60 mAs respectively), on the other hand the influence of mAs value is negligible.

Spasticity as an ictal pattern due to excitotoxic upper motor neuron damage

We describe the case of a man who presented with spasticity and aphasia related to continuous electroencephalographic epileptic activity in the left frontal-temporal regions. Magnetic resonance imaging (MRI) documented in diffusion-weighted images (DWI) two areas of restricted diffusion in the left frontal and temporal cortex. After starting treatment with levetiracetam 3000 mg/day there was progressive recovery of the clinical picture as well as the gradual disappearance of the electroencephalographic seizure activity and the vanishing of areas of restricted diffusion in brain MRI. Based on the clinical, EEG and MRI data, we hypothesized that both aphasia and spasticity represented ictal signs. To our knowledge, this is the first case report of ictal spasticity.

Expression of ATP7B in normal human liver

ATP7B is a copper transporting P-type ATPase, also known as Wilson disease protein, which plays a key role in copper distribution inside cells. Recent experimental data in cell culture have shown that ATP7B putatively serves a dual function in hepatocytes: when localized to the Golgi apparatus, it has a biosynthetic role, delivering copper atoms to apoceruloplasmin; when the hepatocytes are under copper stress, ATP7B translocates to the biliary pole to transport excess copper out of the cell and into the bile canaliculus for subsequent excretion from the body via the bile. The above data on ATP7B localization have been mainly obtained in tumor cell systems in vitro. The aim of the present work was to assess the presence and localization of the Wilson disease protein in the human liver. We tested immunoreactivity for ATP7B in 10 human liver biopsies, in which no significant pathological lesion was found using a polyclonal antiserum specific for ATP7B. In the normal liver, immunoreactivity for ATP7B was observed in hepatocytes and in biliary cells. In the hepatocytes, immunoreactivity for ATP7B was observed close to the plasma membrane, both at the sinusoidal and at the biliary pole. In the biliary cells, ATP7B was localized close to the cell membrane, mainly concentrated at the basal pole of the cells. The data suggest that, in human liver, ATP7B is localized to the plasma membrane of both hepatocytes and biliary epithelial cells.

[CK20 expression in the gastrointestinal tract of the embryo and fetus]

A novel type of cytokeratin, cytokeratin 20 (CK20), was added in 1990 to the classic catalog of human cytokeratins, a heterogeneous group of proteins present in almost all epithelia. In man, the expression of CK20 is almost entirely confined to the gastro-intestinal epithelium, to the urothelium and to Merkel cells. Since only few data are available regarding the expression of CK20 in the developing human intestinal mucosa, we studied CK20 immunoreactivity in fetal and neonatal human gut. Immunoreactivity for CK20 was tested in fetuses and newborns, from the twelfth up to the fortieth week of gestation. In each subject, a specimen from the oesophagus, stomach, small intestine, colon, appendix was studied. Tissue samples were routinely processed and paraffin sections were stained with the CK20-specific antibody IT-Ks 20.8. CK20 immunoreactivity was absent in the oesophageal epithelium and it was unevenly distributed in the gastrointestinal mucosa. Three main patterns of immunoreactivity were observed during normal development: the first, found in the stomach and in the small bowel, is characterized by a progressive increase in CK20 expression during gestation; the second pattern, found in the duodenum, shows a progressive decrease in CK20 expression during gestation; in colon and appendix (third pattern), we did not find significant changes in the degree of immunoreactivity for CK20 during gestation. CK20 is unevenly expressed in developing human intestinal mucosa. The degree of positivity for CK20 appears to be related to the epithelial maturation stage only in gastric and small bowel mucosa. Further studies are needed to verify if the uneven CK20 immunoreactivity in the gastrointestinal tract persists even in adulthood.

Alpha-1-antichymotrypsin immunoreactivity in papillary carcinoma of the thyroid gland

AIM

Papillary thyroid carcinoma (PTC) is the most common malignant tumour of the thyroid gland. The immunohistochemical profile of PTC is characterized by immunoreactivity of tumour cells for cytokeratins, thyroglobulin, vimentin, EMA and S100 protein. Recently, the presence of a serum protease inhibitor, alpha-1-antitrypsin (A1AT), has been demonstrated in tumour cells of PTC. The aim of our study was to test immunoreactivity of PTC for another inhibitor of proteases, alpha-1-antichymotrypsin (A1ACT).

METHODS AND RESULTS

Serial paraffin sections of nine consecutive cases of PTC were tested with anti-A1AT and anti-A1ACT antibodies. No immunoreactivity for A1AT and A1ACT was found in the normal thyroid tissue surrounding each tumour. In seven out of nine cases, tumour cells of PTC showed cytoplasmic immunoreactivity for A1ACT. In two cases, A1ACT was detected even in the nuclei. Immunoreactivity for A1AT was found only in three cases. Two cases of PTC showed no staining for both A1ACT and A1AT. No significant correlation of A1ACT staining was found with various prognostic indices (age of patients, histological pattern, tumour size, presence of regional lymph node metastases). The two cases showing a lack of staining for both A1ACT and A1AT showed a more aggressive clinical behaviour.

CONCLUSIONS

Our preliminary study shows that A1ACT is expressed by tumour cells in a large proportion of papillary carcinomas of the thyroid gland. Its significance remains, to the best of our knowledge, still unknown. The observation of a more aggressive behaviour in the two cases characterized by the absence of immunoreactivity for both A1ACT and A1AT suggests that the presence or absence of protease inhibitors could play a role in controlling tumour progression in PTC.

Patent foramen ovale size and embolic brain imaging findings among patients with ischemic stroke

BACKGROUND AND PURPOSE

Although the cause of stroke among patients with patent foramen ovale (PFO) may be due to paradoxical cerebral embolism (PCE), this mechanism is often difficult to prove. The aim of our study was to evaluate the association between brain imaging findings suggestive of embolism and PFO among ischemic stroke patients.

METHODS

As part of the Northern Manhattan Stroke Study, 95 patients with first ischemic stroke over age 39 underwent transesophageal echocardiography (TEE) for evaluation of a cardiac source of embolism. The stroke subtype was determined by modified NINDS Stroke Data Bank criteria. Stroke subtype and MRI/CT imaging data were evaluated blind to the presence of a PFO. These findings were compared between two groups: patients with medium to large PFO (> or =2 mm) and small (<2 mm) or no PFO.

RESULTS

Of the 95 patients who underwent TEE, 31 (33%) had a PFO. The frequency of PFO was significantly greater among patients with cryptogenic infarcts (19 of 42; 45%) compared with patients with determined cause of stroke (12 of 53, 23%; P=0.02). Medium to large PFOs were found more often among cryptogenic strokes than among infarcts of determined cause (26% versus 6%; P=0.04). Superficial infarcts occurred more often in the group with larger PFOs than in the group with small or no PFOs (50% versus 21%; P=0.02). Patients with medium or large PFOs more frequently had occipital and infratentorial strokes (57% versus 27%; P=0.02).

CONCLUSIONS

Stroke patients with larger PFOs show more brain imaging features of embolic infarcts than those with small PFOs. Larger PFOs may be more likely to cause paradoxical embolization and may help explain the stroke mechanism among patients with no other definite cause.

Spontaneous resolution of pulmonary venous thrombosis after lung transplantation

Thrombus formation at the pulmonary venous anastomotic site after lung transplantation may have catastrophic consequences, including allograft failure and stroke. However, treatment with systemic anticoagulation may facilitate bleeding in the early postoperative period. In the present report, we describe the clinical and transesophageal echocardiographic findings of pulmonary venous thrombosis in two patients in the immediate postoperative period after lung transplantation. Treatment with systemic anticoagulation was not feasible because of extensive postoperative thoracic bleeding in each instance. A conservative approach was taken on the basis of the small size of each thrombus and lack of accelerated flow velocity at the site of the thrombus. Each thrombus resolved spontaneously without clinical sequelae. These two cases suggest that thrombus size and flow velocity at the anastomotic site may be used to guide the clinical management of pulmonary venous thrombosis after lung transplantation.

[Surgery for familial polyposis of the colon. A functional follow-up]

Functional assessment of pelvic pouch procedures for FAP is not different from that of UC and consists of clinical, manometric and radiologic investigations. Ileo-rectal anastomosis and pelvic pouch operation are equally effective for the disease, but function is still questionable after restorative proctocolectomy. Based on a personal series of 43 patients, relevant technical aspects influencing functional results are discussed and guidelines for a correct follow-up of these patients are presented.

Transesophageal echocardiography-guided transvenous biopsy of a cardiac sarcoma

Transvenous endomyocardial biopsy is a well established procedure to diagnose rejection after heart transplantation as well as to assess for other cardiomyopathic processes. However, it is rarely used to obtain samples of unidentified cardiac masses. We report a case of a primary cardiac sarcoma in which the histologic diagnosis was provided by transesophageal echocardiography-guided transvenous biopsy. This procedure is accurate and can avoid the potential risk of a diagnostic thoracotomy.

Late pulmonary venous complications after lung transplantation

Although abnormalities of the pulmonary venous anastomosis in the early postoperative period after lung transplantation have been reported from several centers, late complications related to the pulmonary venous anastomosis have not been described. In the present study, we describe the clinical and transesophageal echocardiographic findings of pulmonary vein anastomotic complications in two patients at 1.9 and 2.3 years after lung transplantation. Both pulmonary venous abnormalities, stenosis in the first instance and thrombosis in the second instance, impaired venous outflow on the affected side causing unilateral edema and pleural effusion. Pulmonary venous abnormalities late after lung transplantation can mimic allograft rejection, opportunistic infection, or heart failure and are best diagnosed by transesophageal echocardiography.

Biphasic response of complement to heparin: fluid-phase generation of neoantigens in human serum and in a reconstituted alternative pathway amplification cycle

We describe a study of the effects of heparin on complement activation through the use of assays for fragment C4d, fragment Bb, and the S-C5b-9 complex (S-MAC). In sera from healthy volunteers, virtually no change was observed in C4d either as a function of time or of heparin concentration, whereas changes in Bb and S-MAC were biphasic. This observation was explored in greater detail in the heparin concentration range 0.001-5.0 u/ml (5 x 10(-3) to 25 micrograms/ml). For both Bb and S-MAC, a significant (P < 0.05) increase in production was noted in the heparin concentration range, 0.01-0.5 u/ml (5 x 10(-2) to 2.5 micrograms/ml). At higher heparin concentrations, Bb and S-MAC production decreased markedly (P < 0.05). We reconstituted the alternative pathway amplification cycle (C3, factor B, and factor D) and studied Bb generation. With reactants at concentrations one tenth those of normal serum, we observed a maximum generation of 13.2 micrograms/ml Bb. Control and heparin at 5 x 10(-4) micrograms/ml generated Bb concentrations of 6.8 and 6.1 micrograms/ml, respectively, for a 2-min incubation; at 5 x 10(-3) micrograms/ml heparin, Bb was increased to 9.8 micrograms/ml. Using isoelectric focusing to study anionic pI shifts in heparin-bound factors B and D, it was found that factor B bound heparin only at the highest heparin concentration studied, i.e., 50 micrograms/ml; factor D, however, bound heparin at a much lower concentration (0.05 micrograms/ml). We conclude that, at low concentrations, heparin activates complement due to potentiation of the alternative pathway amplification cycle in the fluid phase.