Extent Of Volume Loss Research Articles

Assessing the Relationship between Neurocognitive Performance and Brain Volume in Chronic Moderate-Severe Traumatic Brain Injury.

Characterize the scale and pattern of long-term atrophy in gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) in chronic moderate-severe traumatic brain injury (TBI) and its relationship to neurocognitive outcomes. The TBI group consisted of 17 males with primary diagnosis of moderate-severe closed head injury. Participants had not received any systematic, post-acute rehabilitation and were recruited on average 8.36 years post-injury. The control group consisted of 15 males matched on age and education. Neurocognitive battery included widely used tests of verbal memory, visual memory, executive functioning, and attention/organization. GM, WM, and CSF volumes were calculated from segmented T1-weighted anatomical MR images. Voxel-based morphometry was employed to identify brain regions with differences in GM and WM between TBI and control groups. Chronic TBI results in significant neurocognitive impairments, and significant loss of GM and WM volume, and significant increase in CSF volume. Brain atrophy is not widespread, but it is rather distributed in a fronto-thalamic network. The extent of volume loss is predictive of performance on the neurocognitive tests. Significant brain atrophy and associated neurocognitive impairments during the chronic stages of TBI support the notion that TBI results in a chronic condition with lifelong implications.

Advances in the understanding and challenges facing the management of first-episode schizophrenia

Symptoms of schizophrenia typically first appear in adolescence, a time of transition involving biological, social and emotional changes. Schizophrenia and related psychotic illnesses can significantly impair educational and social development; consequently, early identification and treatment is paramount and can affect long-term outcome. Singh (2010) states that early intervention is cost effective and does ameliorate the course of early psychosis, referring specifically to specialist early intervention teams, and their impact on longterm disease outcome and prognosis. Much research is now available in this area, and the papers selected for this supplement focus on intervention at this critical stage, related side effects as well as mortality risk factors associated with schizophrenia. The stress–vulnerability model for schizophrenia suggests that the onset and course of schizophrenia may be determined by an underlying vulnerability, with clinical manifestation being modulated by environmental stressors. It has long been recognized, since the days of Kraepelin (1913), that people with schizophrenia are more likely to be obese and to suffer from metabolic problems such as diabetes mellitus. Leonard et al. review evidence concerning a disordered immune system in schizophrenia and postulate that the relationship between the therapeutic benefits of antipsychotics, the pathology of schizophrenia and these metabolic syndromes are linked to chronic, low-grade inflammation. As maternal infections have been implicated as a causative factor, the resulting inflammatory changes could contribute to neurodevelopmental difficulties, and a sensitized immune system that activates in adolescence. Leonard et al. also discuss the important role played by pro-inflammatory cytokines which modulate neuronal action, differentiation and survival during neurodevelopment, and more specifically influence activity and survival of neurons that utilize neurotransmitters such as serotonin, glutamate and dopamine. Interleukin-6 is particularly important in schizophrenia as it could augment dopaminergic function which, in turn, would affect psychotic symptoms. In addition to the dopaminergic system, some pro-inflammatory cytokines enhance the activity of the glutamatergic system, via the tryptophan–kynurenine pathway, and this might contribute to the cognitive decline sometimes seen in schizophrenia. The inflammation hypothesis of schizophrenia raises the possibility of using anti-inflammatory drugs, such as COX-2 inhibitors, as adjuncts to traditional antipsychotic medication. Van Haren et al. find further evidence to suggest that schizophrenia is a progressive brain disease, and that the most significant decline in grey matter volume occurs in the critical first year of illness. Indeed, there appears to be a linear correlation of grey matter loss with age in schizophrenia, as opposed to the exponential decline seen in healthy individuals. Van Haren et al. also suggest there is a link between the extent of volume loss and severity of symptoms and social functioning, but do acknowledge other studies refute this theory. Although antipsychotic medication remains a confounding factor for grey matter loss, studies in first-degree relatives and at-risk individuals show that cumulative antipsychotic intake can only explain some of these brain volume changes. This review highlights the need for further large studies that follow patients over a long period of time, to further clarify the relationship between brain volume change, antipsychotic intake and outcome. Indeed, the potential to attenuate brain volume changes could potentially improve long-term outcome, which again highlights the need for early intervention and effective treatment in this morbid disease. The advent of ‘atypical’, or second generation antipsychotics, engendered a therapeutic optimism in the treatment of first-episode patients (NICE, 2002). Taylor et al. reviewed the effectiveness of antipsychotic medications in first episode schizophrenia and found traditional randomized controlled trials (RCTs), whilst being necessary, lacked generalizability to real-world clinical scenarios. A need for long-term observational studies to complement the RCTs was recognized, and several high-profile studies have now been published, often using discontinuation rate of antipsychotic medication as the primary outcome. The rationale behind this is that a

CT Scan Features as Predictors of Patient Outcome After Bronchial Intervention in Endobronchial TB

The purpose of this study was to identify the CT scan features that predict patient outcome after reexpansion procedures in patients with the fibrotic stage of endobronchial TB. We retrospectively enrolled 30 patients (four men, 26 women) aged 32 +/- 11 years who had lobar or whole-lung atelectasis as sequela of endobronchial TB. Patients underwent helical CT scan examinations and subsequent reexpansion procedures for atelectasis, including balloon dilatation (n = 2), stent placement (n = 23), and surgical bronchoplasty (n = 5). Two thoracic radiologists evaluated the location and extent of airway narrowing, the extent of volume loss, parenchymal calcification, mucus plugging, and bronchiectasis within atelectasis on preprocedural CT scans. The success of reexpansion procedures was defined as the recovery of lung volume being > 80% of the estimated original volume as determined during follow-up imaging. Preprocedural CT scans and clinical features were compared for the results of the reexpansion procedures using the Wilcoxon two-sample test or Fisher exact test. Atelectasis was reexpanded in 30% (nine of 30) of patients after reexpansion procedures. The presence of parenchymal calcification and bronchiectasis within atelectasis showed a high tendency of failure in reexpansion procedures (P < .001). Mucus plugging, the extent of airway narrowing, volume loss on CT images, and endobronchial TB activity at the time of intervention did not affect the results (P > .05). Patients with successful results were significantly younger than those with unsatisfactory results. Parenchymal calcification and bronchiectasis within atelectasis are correlated with a high chance of failure in reexpansion procedures. Knowledge of CT scan features may help radiologists to predict the results of lung-conserving therapy to avoid unnecessary interventions.

Irrigation, nitrogen, and rootstock effects on volume loss of berries from potted Shiraz vines

Shiraz (synonym Syrah) berry volume increases in two phases and this may be followed by shrinkage during the later stages of ripening. Irrigation regime, nitrogen application rate and rootstock were tested for their effects on the onset of volume loss and extent of volume loss. Maximum berry volume correlated well with volume of berries at 35 d after flowering, the end of the cell division phase. Post-maximum berry shrinkage was not as severe of vines grown with split-root irrigation as compared with standard irrigation. However, these berries were smaller at harvest due to less pre-veraison expansion. Berries grown on vines with standard irrigation had greater post-maximum volume loss than those berries grown in a deficit irrigation treatment. Despite this, maximum berry volume correlated well with final volume in all treatments. N application rate had an effect on the onset of post-veraison expansion but not on the amplitude of maximum berry volume or final berry volume. Deficit irrigation delayed the onset of volume loss by 11 d. Rootstock also had an effect on the onset of volume loss with berries from vines grafted on the rootstock 101-14 Mgt losing volume 7 d earlier than berries from vines grafted on Ramsey. These results suggest that onset and degree of volume loss in Shiraz is sensitive to external influences.

Isofloridosid und die osmoregulation bei Ochromonas malhamensis

Summary An increase or decrease in the osmotic value of the surrounding fluid seems to be balanced directly by the production or degradation of isofloridoside (O-α-D-galactopyranosyl-1 → 1-glycerol) inside the cells of Ochromonas malhamensis. Some more data on the physiology of this osmoregulation system will be reported here. 1. The amount of isofloridoside piled up in the cells does not depend on the chemical nature but on the osmolarity of the substances added (fig. 2). The observed increase in the concentration of some free amino acids contributes less than 8 percent towards the osmotic balance of the cells, whereas the concentrations of K+ and Na+ remain constant (fig. 3). This sustains the conclusion drawn from other experiments also [ref. 1, 2, 7] that the osmotic balance in Ochromonas is predominantly achieved by the isofloridoside mechanism. 2. The ecological significance of the mechanism is demonstrated by the fact that the level of isofloridoside in the algae changes parallel to the osmotic value of the nutrient solution during growth of the cultures (fig. 1). 3. After an increase in osmotic pressure a constant rate of isofloridoside formation is reached instantly or within a few minutes (fig. 4). This is not affected by preincubation of the algae with cycloheximide (fig. 5) or actinomycin D. Both findings suggest that the regulation of the isofloridoside pathway may occur by activation of already existing enzyme molecules rather than by the induction of enzyme new-formation. 4. The rate of isofloridoside formation and the termination of its production depend both on the extent of the osmotic stress (fig. 4). This suggests that the regulation of the isofloridoside production involves a mechanism which can sense gradual differences in the outside osmotic pressure as well as a feed-back type of mechanism which can measure the status of osmotic balance already reached. 5. Light scattering (fig. 6) as well as direct measurements (fig. 7 and 8) show that the cells shrink suddenly after an increase in osmotic pressure and regain the cell volume in the course of isofloridoside production. The extent of volume loss is the same with various osmotic pressure substances and is higher with higher concentrations (fig. 9). The shrinkage occurs roughly within the same time interval as the start of isofloridoside production. It seems, therefore, possible that on the various parameters altered by the shrinkage is involved in the translation of the physical-chemical stimulus into a first biochemical alteration which in turn leads to the regulation of the isofloridoside pathway.