Comparison of the mesophilic and thermophilic anaerobic digestion of spent cow bedding in leach-bed reactors.

Anaerobic digestion of spent cow bedding in batch leach-bed reactors (LBRs) was compared in mesophilic and thermophilic conditions for the first time. Results show that the use of thermophilic conditions enhanced only the degradation kinetics of easily-degradable matter during the first days of the digestion, whereas similar methane yields (80% of the Biomethane Potential) were reached after 42days at both temperatures. Therefore, the anaerobic digestion in LBRs of spent cow bedding, a substrate rich in slowly-degradable compounds, was not improved in term of methane production considering the overall digestion time. Moreover, the high initial biogas production rate in thermophilic reactors was found to significantly reduce the energetic performance of the cogeneration unit at industrial scale, leading to a 5.9% decrease in the annual electricity production when compared to a mesophilic one.

Leachate flush strategies for managing volatile fatty acids accumulation in leach-bed reactors.

In anaerobic leach-bed reactors (LBRs) co-digesting an easily- and a slowly-degradable substrate, the importance of the leachate flush both on extracting volatile fatty acids (VFAs) at the beginning of newly-started batches and on their consumption in mature reactors was tested. Regarding VFA extraction three leachate flush-rate conditions were studied: 0.5, 1 and 2Lkg-1TSd-1. Results showed that increasing the leachate flush-rate during the acidification phase is essential to increase degradation kinetics. After this initial phase, leachate injection is less important and the flush-rate could be reduced. The injection in mature reactors of leachate with an acetic acid concentration of 5 or 10gL-1 showed that for an optimized VFA consumption in LBRs, VFAs should be provided straight after the methane production peak in order to profit from a higher methanogenic activity, and every 6-7h to maintain a high biogas production rate.

Mesophilic anaerobic digestion of several types of spent livestock bedding in a batch leach-bed reactor: substrate characterization and process performance.

Spent animal bedding is a valuable resource for green energy production in rural areas. The properties of six types of spent bedding collected from deep-litter stables, housing either sheeps, goats, horses or cows, were compared and their anaerobic digestion in a batch Leach-Bed Reactor (LBR) was assessed. Spent horse bedding, when compared to all the other types, appeared to differ the most due to a greater amount of straw added to the litter and a more frequent litter change. Total solids content appeared to vary significantly from one bedding type to another, with consequent impact on the methane produced from the raw substrate. However, all the types of spent bedding had similar VS/TS (82.3-88.9)%, a C/N well-suited to anaerobic digestion (20-28, except that of the horse, 42) and their BMPs were in a narrow range (192-239NmLCH4/gVS). The anaerobic digestion in each LBR was stable and the pH always remained higher than 6.6 regardless of the type of bedding. In contrast to all the other substrates, spent goat bedding showed a stronger acidification resulting in a methane production lag phase. Finally, spent bedding of different origins reached, on average, (89±11)% of their BMP after 60days of operation. This means that this waste is well-suited for treatment in LBRs and that this is a promising process to recover energy from dry agricultural waste.

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.

Pulse wave velocity and augmentation index, but not intima-media thickness, are early indicators of vascular damage in hypercholesterolemic children.

BACKGROUND: Arterial stiffness is an important determinant of cardiovascular risk. It is associated with several cardiovascular risk factors, including hypertension, diabetes and cigarette smoking. However, there are conflicting data about the relationship between arterial stiffness and hypercholesterolemia. Furthermore, augmentation index (AIx), a measure of systemic arterial stiffness, has not been previously investigated in hypercholesterolemic (HCh) children. Aim of our study was to evaluate local and systemic arterial stiffness as well as carotid intima-media thickness (IMT) in HCh children and also to investigate the relation between serum cholesterol levels and arterial stiffness. MATERIALS AND METHODS: We determined lipid profile, body mass index, blood pressure, heart rate, carotid IMT and several arterial stiffness parameters, as beta-index, elastic modulus (E(p)), arterial compliance (AC), pulse wave velocity (PWV) and AIx, in 44 untreated HCh children (mean age 10.7 +/- 2.8 years; 18 with familial hypercholesterolemia, FH, and 26 with primary hypercholesterolemia, PHC) and 18 age- and sex-matched controls. HCh children never received any medication, including antihypertensive and lipid lowering drugs. RESULTS: Respect to controls and to PHC, FH had significantly higher (P < 0.001) beta-index (5.22 +/- 1.13 vs. 3.13 +/- 0.74 and 3.60 +/- 1.02), PWV (4.72 +/- 0.72 m s(-1) vs. 3.66 +/- 0.55 m s(-1) and 4.10 +/- 0.67 m s(-1)), AIx (3.55 +/- 3.97% vs. -4.43 +/- 4.09% and 0.61 +/- 2.39%) and E(p) (64.4 +/- 19.6 kPa vs. 36.2 +/- 11.3 kPa and 42.9 +/- 13.1), whereas AC (1.25 +/- 0.48 mm(2) kPa(-1) vs. 1.9 +/- 0.43 mm(2) kPa(-1) and 1.62 +/- 0.43 mm(2) kPa(-1)) was lower (P < 0.001). There was no significant difference in carotid IMT and blood pressure values between the groups. The multiple regression analysis showed a significant association of arterial stiffness values with plasma cholesterol levels (P < 0.0001). CONCLUSION: Our findings show that local and systemic arterial stiffness are increased in asymptomatic, normotensive HCh children, suggesting that HCh plays a key role in arterial mechanical impairment since the paediatric age.

Disulfiram-ethanol induced delirium.

OBJECTIVE: To report a case of delirium, without major autonomic symptoms, as the primary manifestation of concomitant use of alcohol while taking disulfiram. CASE SUMMARY: A 50-year-old white woman with a history of bipolar disorder, type I, and alcohol dependence being treated with disulfiram was admitted to an inpatient psychiatric unit with a three- to four-day history of a change in mental status, including deficits in orientation, concentration, and visual hallucinations. Significant finding on review of systems included the spurious report of a 9.1-kg weight loss. Tachycardia and nonfocal neurologic signs on physical examination were also noted. Extensive metabolic, infectious, and neurologic work-up revealed no abnormalities that alone could explain the patient's acute confusional state. It was subsequently discovered that the patient had imbibed alcohol on at least two separate occasions while taking disulfiram prior to her change in mental status and that a similar, although shorter, experience had occurred previously. DISCUSSION: This is the first case, to the authors' knowledge, that describes an acute confusional state as the primary manifestation of a patient taking alcohol while being prescribed disulfiram as aversive therapy for alcohol abuse. Possible pathophysiologic mechanisms for delirium as a complication of alcohol ingestion while taking disulfiram include disturbances in various neuroendocrine axes, neurotransmitter systems, and metabolic derangements. Other reports of possible neuropsychiatric complications of disulfiram therapy are also reviewed. CONCLUSIONS: The differential diagnosis for the presentation of delirium in a patient known to be undergoing aversive therapy for alcohol dependence with disulfiram should include nonadherence to alcohol abstinence.

Mucormycosis after bone marrow transplantation: report of four cases in thalassemia and review of the literature.

We report four cases of mucormycosis that occurred among 711 patients who underwent BMT for thalassemia, and review 18 additional cases among BMT recipients that were reported in the English-language literature. All these patients were polytransfused and were in advanced phase of disease with severe acquired hemochromatosis. The sites of infection were sinonasal, rhinocerebral-pulmonary, pulmonary and pulmonary-central nervous system. Mucormycosis was the primary cause of death in three of four patients. Two infections were detected within the first 100 days after BMT. Only one of the four patients had partial resolution of sinonasal mucormycosis following aggressive antifungal therapy combined with hyperbaric oxygen treatment.

Psychogenic status epilepticus.

A patient was brought to the Emergency Department in presumed status epilepticus. However, the seizure had many of the clinical characteristics that, in combination, were suggestive of a psychogenic event including asynchronous extremity movements, forward pelvic thrusting, and geotrophic eye movements. An arterial blood gas and serum electrolytes were normal despite one-half hour of tonic-clonic activity, and supported the diagnosis of a nonneurogenic event. The patient became conversant toward the end of the event, which confirmed that the seizure was nonepileptogenic.

Psychogenic seizures.

Psychogenic seizures are nonepileptic events that are varied in their clinical presentations. These events can be psychiatric or physiologic in their origin and can occur concomitantly in patients with epileptic seizure disorders. The diagnosis often requires laboratory and electrophysiologic investigation; however, historical, clinical, and laboratory findings can aid in making the diagnosis.

Cognitive bias, functional cortical geometry, and the frontal lobes: laterality, sex, and handedness.

Abstract Performance of patients with quadrant lesions on the inherently ambiguous Cognitive Bias Task (CBT) suggests sexual dimorphism in the fundamental aspects of functional cortical geometry, by emphasizing different cerebral axes. In right-handed males, extreme context-dependent and context-independent response selection biases are reciprocally linked to left vs. right frontal systems. In right-handed females, these complementary biases appear to be reciprocally linked to posterior vs. frontal cortices. Frontal lobe functions are more lateralized in males than females due to sexual dimorphism of the left frontal systems. Both in males and females, patterns of CBT scores in non-right-handers with quadrant lesions are opposite to those found in right-handers. This suggests the existence of two functionally and neurally distinct cognitive selection mechanisms. Both mechanisms involve the frontal lobes, but their exact neuroanatomy depends on sex and handedness.

Refractory status epilepticus in adults.

The management of status epilepticus has improved over the past 20 years, resulting in a substantial decrease in the associated morbidity and mortality. Patients who have seizures that are refractory to initial pharmacologic interventions tend to have significant underlying toxic, metabolic, structural, or infectious disorders, and therefore management of refractory status epilepticus must focus on stabilization and on identification and correction of seizure etiology. Regardless of etiology, the faster the seizures are brought under control, the better the prognosis. Risk of central nervous system injury increases after 30 minutes of seizure activity, and therefore efforts should focus on controlling the abnormal electrical discharges at the earliest time possible, preferably within one hour. Benzodiazepines, phenytoin, and phenobarbital remain the most commonly used first- and second-line anticonvulsants, have proven effective in cases of status epilepticus, and should be administered within the first 45 minutes of management. For refractory status epilepticus, pentobarbital anesthesia is evolving as an effective and recommended treatment modality and should be instituted immediately after phenytoin and phenobarbital loading. The role of other anticonvulsants remains to be investigated in controlled clinical trials.

Interictal EEG topography of frontal lobe epilepsy.

Ictal localization of seizure discharges in the frontal lobe is difficult and not easily resolved by simple translation of techniques that have proved useful for localization within the temporal lobe. There is need for improved interictal localization of functional abnormalities within the frontal lobe utilizing CET and other methods of functional localization including magnetoencephalography, cerebral blood flow, and cerebral metabolism. It is likely that improved localization within the frontal lobe and clarification of clinical syndromes of frontal epilepsy will be obtained through the use of a combination of these interictal methods, aided by the results of intracranial ictal recording and surgical extirpation (7a,b,10a,b,15a-c).

Emergency department approach to managing seizures in pregnancy.

Seizures in pregnancy pose risks for both the mother and the fetus and must be managed aggressively. Antiepileptic drugs have some teratogenic potential, but the risks are not as profound as reported in earlier literature. There is definitely less risk to the fetus from anticonvulsant exposure than from uncontrolled seizures. The evaluation of a pregnant woman with new-onset seizures is the same as for the nonpregnant patient, including head computed tomography with appropriate abdominal shielding. Status epilepticus management is based on IV benzodiazepines, phenytoin, or phenobarbital. Good fetal outcome is dependent on rapid seizure control. Management of eclampsia is controversial. There is little evidence that magnesium sulfate has anticonvulsant properties, and its use as such will probably decline steadily in the future. At present, it is reasonable to manage eclamptic seizures in the same way that status epilepticus is managed.

Application of singular value decomposition to topographic analysis of flash-evoked potentials.

Singular value decomposition is a robust numerical method for decomposing a matrix of multichannel EEG or EP data into a sharply reduced set of features with corresponding waveform, amplitude, and spatial vectors. In 19 normal subjects aged 19 to 40 years, the three largest features computed by the SVD algorithm accounted for 93-98 percent of the total variance of the averaged flash-evoked potential. There was good separation of major brain areas as well as clustering of related electrode sites. Orthogonal rotation of the three spatial vectors is essential to see clustering of brain areas across subjects. Three-dimensional display showed the regular presence of orthonormal occipital, frontopolar, and vertex spatial vectors. Since the spatial feature vectors cluster tightly and yet are orthonormal, statistical comparison of patients with normal control groups will be facilitated.