Association between increased theta cordance and early response to ECT in late-life depression.

OBJECTIVES: More than half of patients with major depression who do not respond to initial antidepressants become treatment resistant (TRD), and while electroconvulsive therapy (ECT) is effective, it involves anesthesia and other medical risks that are of concern in geriatric patients. Past studies have suggested that theta cordance (TC), a correlate of cerebral metabolism measured by electroencephalography, could guide treatment decisions related to patient selection and engagement of the therapeutic target. METHODS/DESIGN: Eight patients with late-life treatment resistant depression (LL-TRD) underwent magnetoencephalography (MEG) at baseline and following seven sessions of ECT. We tested whether the mean and regional frontal cortex TC were able to differentiate early responders from nonresponders. RESULTS: Five patients whose depression severity decreased by >30% after seven sessions were considered early responders. We found no baseline differences in mean frontal TC between early responders compared with nonresponders, but early responders exhibited a significant increase in TC following ECT. Further, we found that compared with nonresponders, early responders exhibited a greater change in TC specifically within the right prefrontal cortex. CONCLUSIONS: These results support the hypothesis that increases in frontal TC are associated with antidepressant response. We expand on previous findings by showing that this change is specific to the right prefrontal cortex. Validation of this neural marker could contribute to improved ECT outcomes, by informing early clinical decisions about the acute efficacy of this treatment.

Quantitatively validating the efficacy of artifact suppression techniques to study the cortical consequences of deep brain stimulation with magnetoencephalography.

Deep brain stimulation (DBS) is an established and effective treatment for several movement disorders and is being developed to treat a host of neuropsychiatric disorders including epilepsy, chronic pain, obsessive compulsive disorder, and depression. However, the neural mechanisms through which DBS produces therapeutic benefits, and in some cases unwanted side effects, in these disorders are only partially understood. Non-invasive neuroimaging techniques that can assess the neural effects of active stimulation are important for advancing our understanding of the neural basis of DBS therapy. Magnetoencephalography (MEG) is a safe, passive imaging modality with relatively high spatiotemporal resolution, which makes it a potentially powerful method for examining the cortical network effects of DBS. However, the degree to which magnetic artifacts produced by stimulation and the associated hardware can be suppressed from MEG data, and the comparability between signals measured during DBS-on and DBS-off conditions, have not been fully quantified. The present study used machine learning methods in conjunction with a visual perception task, which should be relatively unaffected by DBS, to quantify how well neural data can be salvaged from artifact contamination introduced by DBS and how comparable DBS-on and DBS-off data are after artifact removal. Machine learning also allowed us to determine whether the spatiotemporal pattern of neural activity recorded during stimulation are comparable to those recorded when stimulation is off. The spatiotemporal patterns of visually evoked neural fields could be accurately classified in all 8 patients with DBS implants during both DBS-on and DBS-off conditions and performed comparably across those two conditions. Further, the classification accuracy for classifiers trained on the spatiotemporal patterns evoked during DBS-on trials and applied to DBS-off trials, and vice versa, were similar to that of the classifiers trained and tested on either trial type, demonstrating the comparability of these patterns across conditions. Together, these results demonstrate the ability of MEG preprocessing techniques, like temporal signal space separation, to salvage neural data from recordings contaminated with DBS artifacts and validate MEG as a powerful tool to study the cortical consequences of DBS.

An evaluation of psychological well-being and secular trends in the occurrence of type 2 diabetes 1993 – 2014 in outpatients in a community

OBJECTIVE: To evaluate psychosocial well-being and secular trends among outpatient diabetics in community-dwelling Trinidadian patients. METHODS AND DESIGN: We used a cross-sectional study design. The population consisted of all adult patients (>18 years) with Type 2 diabetes (T2DM), receiving care at the main primary health care facility serving that community. The communities came from the North Central Regional Health Authority (RHA) and the Eastern RHA. The WHO-5 Well Being Index was used to determine quality of life and psychological wellbeing. Scores ranged from 0 (worst) to 100 (best). RESULTS: The sample comprised 301 participants. The mean age was 60.78 years (SD ñ11.5) with an inter-quartile range of 51-70 years with no significant age difference between males and females (73.8 versus 75.1, p = 0.235). Females outnumbered males, f:m 1.5:1. Sample participants consisted of 42% Africans and 33.2% South East Asians (SEA). Of the participants, 66% were found to be overweight or obese. One half of the participants scored <50 indicating they were not content with their quality of life, with 1.7% likely to be depressed. There was an increase in patients between the period 1990’s to 2004-14 and the occurrence of cases in younger age groups. For the first time in 2004-09 there were patients aged 29-30 years and there were patients aged 19 -28 years in 2010-14. CONCLUSION: We provide evidence that at the community T2DM is increasingly occurring and shifting towards younger age groups and there was significant dissatisfaction in the quality of their lives.

Electron absorbed fractions of energy and S-values in an adult human skeleton based on µCT images of trabecular bone.

When the human body is exposed to ionizing radiation, among the soft tissues at risk are the active marrow (AM) and the bone endosteum (BE) located in tiny, irregular cavities of trabecular bone. Determination of absorbed fractions (AFs) of energy or absorbed dose in the AM and the BE represent one of the major challenges of dosimetry. Recently, at the Department of Nuclear Energy at the Federal University of Pernambuco, a skeletal dosimetry method based on µCT images of trabecular bone introduced into the spongiosa voxels of human phantoms has been developed and applied mainly to external exposure to photons. This study uses the same method to calculate AFs of energy and S-values (absorbed dose per unit activity) for electron-emitting radionuclides known to concentrate in skeletal tissues. The modelling of the skeletal tissue regions follows ICRP110, which defines the BE as a 50 µm thick sub-region of marrow next to the bone surfaces. The paper presents mono-energetic AFs for the AM and the BE for eight different skeletal regions for electron source energies between 1 keV and 10 MeV. The S-values are given for the beta emitters (14)C, (59)Fe, (131)I, (89)Sr, (32)P and (90)Y. Comparisons with results from other investigations showed good agreement provided that differences between methodologies and trabecular bone volume fractions were properly taken into account. Additionally, a comparison was made between specific AFs of energy in the BE calculated for the actual 50 µm endosteum and the previously recommended 10 µm endosteum. The increase in endosteum thickness leads to a decrease of the endosteum absorbed dose by up to 3.7 fold when bone is the source region, while absorbed dose increases by ∼20% when the beta emitters are in marrow.

Taking the next step in 2005, the year of the diabetic foot.

OBJECTIVES: To determine the age-standardized rate of lower limb amputations among Type 2 diabetics admitted to the Port of Spain General Hospital (POSGH), San Fernando General Hospital (SFGH) and Sangre Grande County Hospital (SGCH) for the period 2000-2004. To determine in-hospital mortality following amputation, for the same period. To determine the risk factors that contributed to diabetic foot complications. DESIGN AND METHODS: All patients who had a lower limb amputation at the three major public health institutions in Trinidad during the study period were enrolled. In addition patients attending the surgical out-patient clinic and currently admitted to the ward with a diabetic septic foot was selected for the administration of a questionnaire to determine the major contributing factors. Data on the type of amputation, age, sex, ethnicity, from which an age-standardized mortality rate, was determined for the age group 30-60. RESULTS: Of 822 patient files examined, 515 (80 per cent) of these major amputations were performed on Type 2 diabetics, of which 352 (68 per cent) were AKA and 163 (32 per cent) were BKA. The AKA:BKA ratio for the period 2000-2004 was 2.2:1. There was a significant difference between the mean ages at which females had a major amputation to males (p=0.001). The overall ratio of Africans to South East Asians was 1.5:1 amongst the Type 2 diabetic amputees. For major amputations the average length of stay was found to be 22.5 (0-192) days. The age-standardized rate for the age group 30-60 was 13.85 per 100,000 for 2004. Of 66 deaths, 31 (47 per cent) were septicemia cases and 14 (21 per cent) cardio-respiratory failure cases. Finally, of 97 persons interviewed, the major causative agent for diabetic foot complications and amputations was foot trauma (51 per cent). CONCLUSION: Type 2 diabetic amputation status of Trinidad would seem to have improved as shown by this study.

Taking the next step in 2005, the year of the diabetic foot.

OBJECTIVES: To determine the age-standardized rate of lower limb amputations among Type 2 diabetics admitted to the Port of Spain General Hospital (POSGH), San Fernando General Hospital (SFGH) and Sangre Grande County Hospital (SGCH) for the period 2000-2004. To determine in-hospital mortality following amputation, for the same period. To determine the risk factors that contributed to diabetic foot complications. DESIGN AND METHODS: All patients who had a lower limb amputation at the three major public health institutions in Trinidad during the study period were enrolled. In addition patients attending the surgical out-patient clinic and currently admitted to the ward with a diabetic septic foot was selected for the administration of a questionnaire to determine the major contributing factors. Data on the type of amputation, age, sex, ethnicity, from which an age-standardized mortality rate, was determined for the age group 30-60. RESULTS: Of 822 patient files examined, 515 (80%) of these major amputations were performed on Type 2 diabetics, of which 352 (68%) were AKA and 163 (32%) were BKA. The AKA:BKA ratio for the period 2000-2004 was 2.2:1. There was a significant difference between the mean ages at which females had a major amputation to males (p=0.001). The overall ratio of Africans to South East Asians was 1.5:1 amongst the Type 2 diabetic amputees. For major amputations the average length of stay was found to be 22.5 (0-192) days. The age-standardized rate for the age group 30-60 was 13.85 per 100,000 for 2004. Of 66 deaths, 31 (47%) were septicemia cases and 14 (21%) cardio-respiratory failure cases. Finally, of 97 persons interviewed, the major causative agent for diabetic foot complications and amputations was foot trauma (51%). CONCLUSION: Type 2 diabetic amputation status of Trinidad would seem to have improved as shown by this study. However, steps must be taken to improve patient awareness about prevention and care of the diabetic foot. Doctors must also seek to increase their vigilance when screening diabetic patient in the primary care setting in order to prevent the late detection and treatment of the septic lower limb.

Gene regulation in Drosophila mulleri, D. arizonensis, and their hybrids: The nucleolar organizer.

Typically, Drosophila have nucleolar organizer regions (NORs) confined to the sex chromosomes. Salivary gland cells of hybrids between Drosophila mulleri females and D. arizonensis males exhibit features in nucleolar organizer regulation that differentiate the species on one hand, and which show an interplay between the X and the microchromosome on the other hand.In the hybrid females only the X chromosome from D. arizonensis appears to be attached to the nucleolus. In the hybrid males the X chromosome, from D. mulleri, also does not seem to contain a functional NOR. However, in hybrid males the microchromosome from D. arizonensis increases greatly in size and appears to be associated with the nucleolus. The increase in size of the microchromosome involves a 4-fold increase in DNA content. In D. arizonensis and in hybrid females the NOR of the microchromosome appears to be suppressed. In the absence of an arizonensis X chromosome, the NOR of the microchromosome typically is active, while the NOR on the mulleri X chromosome remains suppressed. Therefore, the ribosomal cistrons and interchromosomal regulator element appears to be duplicated on both the X chromosome and microchromosome of D. arizonensis, but with epistatic suppression of the microchromosomal NOR by the arizonensis X-linked NOR. Either arizonensis NOR, X linked or microchromosomal, suppresses the mulleri NOR.