Memory differences by sex, but not by previous diagnosis of major depressive disorder

Memory difficulties are consistently reported in Major Depressive Disorder (MDD). Nonetheless, it has not been thoroughly investigated as to whether these deficits persist during remission from MDD. A group of 32 healthy young adults with no history of a mood disorder (M_age = 20.8, SD = 2.1) and 62 remitted depressed young adults (M_age = 21.1, SD = 1.9) completed a neuropsychological battery. The test battery included two measures of nonverbal memory, two measures of verbal memory, and a measure of performance validity. The testing session was repeated three to six weeks later to determine performance stability. No differences were found between healthy controls and remitted depressed patients in either memory domain (all ps > .05) and improvement in performance was exhibited over time for both groups (p = 0.004). Potential practice effects are examined. We found a stronger performance for women than men (p = 0.003), particularly for the Semantic List Learning Task (SLLT) (p = .047). Verbal and nonverbal memory and effort may not be impacted in those who are in a remitted state of MDD, early in the course of the illness. Women demonstrated auditory memory superiority over men, similar to prior research.

Two Year Outcomes, Cognitive and Behavioral Markers of Decline in Healthy, Cognitively Normal Older Persons with Global Deterioration Scale Stage 2 (Subjective Cognitive Decline with Impairment)

BACKGROUND

Little is known with respect to behavioral markers of subjective cognitive decline (SCD), a condition initially described in association with Global Deterioration Scale (GDS) stage 2.

OBJECTIVE

Two-year interval behavioral markers were investigated herein.

METHODS

Subjects from a published 7-year outcome study of GDS stage 2 subjects were selected. This study had demonstrated a hazard ratio of 4.5 for progression of GDS stage 2, in comparison with GDS stage 1 (no subjective or objective cognitive decline) subjects, after controlling for demographic and temporal variables. Because GDS 2 subjects have previously demonstrated impairment in comparison with healthy persons free of complaints, we herein suggest the terminology "SCD(I)" for these persons. 98 SCD(I) persons, 63 women and 35 men, mean baseline age, 67.12±8.75 years, with a mean educational background of 15.55±2.60 years, and mean baseline MMSE scores of 28.9±1.24 were followed for 2.13±0.30 years.

RESULTS

Observed annual decline on the GDS was 6.701% per annum, very close to a 1986 published estimate. At follow up, the MMSE, and 7 of 8 psychometric tests did not decline significantly. Of 21 Hamilton Depression Scale items, 2 improved and the remainder were unchanged. Anxieties declined from multiple perspectives. The Brief Cognitive Rating Scale (BCRS) declined significantly (p < 0.001), with component declines in Remote memory (p < 0.01), and Functioning/self-care (p = 0.01).

CONCLUSION

SCD(I) persons decline at an annual rate of approximately 6.7% /year from several recent studies. The BCRS assessments and the Digit Symbol Substitution Test can be sensitive measures for future studies of progression mitigation.

A new semantic list learning task to probe functioning of the Papez circuit

INTRODUCTION

List learning tasks are powerful clinical tools for studying memory, yet have been relatively underutilized within the functional imaging literature. This limits understanding of regions such as the Papez circuit that support memory performance in healthy, nondemented adults.

METHOD

The current study characterized list learning performance in 40 adults who completed a semantic list learning task (SLLT) with a Brown-Peterson manipulation during functional magnetic resonance imaging (fMRI). Cued recall with semantic cues and recognition memory were assessed after imaging. Internal reliability, convergent, and discriminant validity were evaluated.

RESULTS

Subjects averaged 38% accuracy in recall (62% for recognition), with primacy but no recency effects observed. Validity and reliability were demonstrated by showing that the SLLT was correlated with the California Verbal Learning Test (CVLT), but not with executive functioning tests, and by high intraclass correlation coefficient across lists for recall (.91). fMRI measurements during encoding (vs. silent rehearsal) revealed significant activation in bilateral hippocampus, parahippocampus, and bilateral anterior and posterior cingulate cortex. Post hoc analyses showed increased activation in anterior and middle hippocampus, subgenual cingulate, and mammillary bodies specific to encoding. In addition, increasing age was positively associated with increased activation in a diffuse network, particularly frontal cortex and specific Papez regions for correctly recalled words. Gender differences were specific to left inferior and superior frontal cortex.

CONCLUSIONS

This is a clinically relevant list learning task that can be used in studies of groups for which the Papez circuit is damaged or disrupted, in mixed or crossover studies at imaging and clinical sites.

The double burden of age and major depressive disorder on the cognitive control network

Poor cognitive control (CC) is common among older individuals with major depressive disorder (OMDD). At the same time, studies of CC in OMDD with fMRI are relatively limited and often have small samples. The present study was conducted to further examine poor CC in OMDD with early onset depression, as well as to investigate the interactive effects of MDD and aging on cognitive control. Twenty OMDD, 17 older never-depressed comparisons (ONDC), 16 younger adults with MDD (YMDD), and 18 younger never-depressed comparisons (YNDC) participated. All participants completed the Go level of the Parametric Go/No-Go Test, which requires sustained attention and inhibitory control while undergoing functional MRI (fMRI). YNDC were faster in reaction times (RTs) to go targets relative to the other 3 groups, and the YMDD group was faster than the OMDD group. fMRI effects of both age and diagnosis were present, with greater activation in MDD, and in aging. Additionally, the interaction of age and MDD was also significant, such that OMDD exhibited greater recruitment of fronto-subcortical regions relative to older comparisons. These results are consistent with prior research reporting that OMDD recruit more fronto-striatal regions in order to perform at the same level as their never-depressed peers, here on a task of sustained attention and inhibitory control. There may be an interaction of cognitive aging and depression to create a double burden on the CC network in OMDD, including possible fronto-striatal compensation during CC that is unique to OMDD, as younger MDD individuals do not show this pattern.

Disruption of response inhibition circuits in prodromal Huntington disease

Cognitive changes in the prodromal phase of Huntington disease (prHD) are found in multiple domains, yet their neural bases are not well understood. One component process that supports cognition is inhibitory control. In the present fMRI study, we examined brain circuits involved in response inhibition in 65 prHD participants and 36 gene-negative (NEG) controls using the stop signal task (SST). PrHD participants were subdivided into three groups (LOW, MEDIUM, HIGH) based on their CAG-Age Product (CAP) score, an index of genetic exposure and a proxy for expected time to diagnosis. Poorer response inhibition (stop signal duration) correlated with CAP scores. When response inhibition was successful, activation of the classic frontal inhibitory-network was normal in prHD, yet stepwise reductions in activation with proximity to diagnosis were found in the posterior ventral attention network (inferior parietal and temporal cortices). Failures in response inhibition in prHD were related to changes in inhibition centers (supplementary motor area (SMA)/anterior cingulate and inferior frontal cortex/insula) and ventral attention networks, where activation decreased with proximity to diagnosis. The LOW group showed evidence of early compensatory activation (hyperactivation) of right-hemisphere inhibition and attention reorienting centers, despite an absence of cortical atrophy or deficits on tests of executive functioning. Moreover, greater activation for failed than successful inhibitions in an ipsilateral motor-control network was found in the control group, whereas such differences were markedly attenuated in all prHD groups. The results were not related to changes in cortical volume and thickness, which did not differ among the groups. However, greater hypoactivation of classic right-hemisphere inhibition centers [inferior frontal gyrus (IFG)/insula, SMA/anterior cingulate cortex (ACC)] during inhibition failures correlated with greater globus pallidus atrophy. These results are the first to demonstrate that response inhibition in prHD is associated with altered functioning in brain networks that govern inhibition, attention, and motor control.

Plain abdominal radiography in clinically suspected appendicitis: diagnostic yield, resource use, and comparison with CT

This study determined the diagnostic utility and hospital resource impact of plain abdominal radiography in emergency department patients with suspected appendicitis. The authors reviewed medical records of 821 consecutive patients hospitalized for suspected appendicitis; 78% had plain abdominal radiography. Sixty-four percent had appendicitis. Radiographic findings were noted in 51% of patients with, and 47% of patients without appendicitis; no individual radiographic finding was sensitive or specific. Specific conditions were suggested in 10% of impressions; these failed to correlate with final clinical diagnoses 57% of the time. Hospital cost per abdominal radiograph was $67; cost per specific, correct radiographic diagnosis was $1,593. This is compared with $270 per appendiceal computed tomography scan (based on recent literature data). The authors conclude that plain abdominal radiographs in patients with suspected appendicitis are neither sensitive nor specific, are frequently misleading, are costly per specific and correct diagnosis, and should not be routinely obtained on patients with suspected appendicitis.

A possible role for a low molecular weight peptide in regulation of testosterone production by rat Leydig cells

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of Percoll purified Leydig cell proteins from 20- and 120-day-old rats revealed a significant decrease in a low molecular weight peptide in the adult rats. Administration of human chorionic gonadotropin to immature rats resulted in a decrease in the low molecular weight peptide along with increase in testosterone production. Modulation of the peptide by human chorionic gonadotropin could be confirmed by Western blotting. The presence of a similar peptide could be detected by Western blotting in testes of immature mouse, hamster, guinea pig but not in adrenal, placenta and corpus luteum. Administration of testosterone propionate which is known to inhibit the pituitary luteinizing hormone levels in adult rats resulted in an increase in the low molecular weight peptide, as checked by Western blotting. It is suggested that this peptide may have a role in regulation of acquisition of responsiveness to luteinizing hormone by immature rat Leydig cells.

Outbreak of dengue fever in rural areas of Parbhani district of Maharashtra (India)

Outbreak of dengue fever in Chikalthana, Pimpalgaon and Waloor villages in Parbhani district of Maharashtra (India) were investigated. Clinically, the illness was typical of dengue fever except for the absence of maculopapular rash. A total of 42 acute, 14 late acute, 73 convalescent and 19 sera from contacts were collected. Of the 15 virus isolates, 12 were identified as dengue virus type 2 and 1 as dengue virus type 1. Serological tests confirmed the etiological role of dengue virus in the outbreak. House-to-house survey was carried out in Chikalthana and Pimpalgaon villages. Overall, 15.09 per cent of the surveyed population was affected during the outbreak and attack rate was higher at Pimpalgaon. A tendency of water storage was observed in the households and concomitant entomological studies proved Aedes aegypti breeding. Higher prevalence of dengue fever was noted among larger families and in families that had two or more patients, the commonest duration between the first and the last patient was often less than 5 days.

Numerical solution of non-steady magnetohydrodynamic flow of blood through a porous channel

Magnetohydrodynamic (MHD) principles may be used to decelerate the flow of arterial blood and hence be of potential value in the treatment of cardiovascular disorders associated with an accelerated circulation. We examine the non-steady flow of blood in a porous parallel plate channel under the influence of a transverse magnetic field and different pressure gradients.

Isolation of West Nile virus from the brains of children who had died of encephalitis

The isolation of West Nile virus from the brain tissue of three children who died of encephalitis in Mysore and Kolar districts of Karnataka State, India, is reported. This is the first such report from India. The significance of these isolations with reference to the role of West Nile virus in encephalitis in children in southern India is discussed.