720 research outputs found
Guanidinoacetate methyltransferase (GAMT) deficiency: a rare but treatable epilepsy
Epilepsy commonly presents in childhood as part of a syndrome, and some such children may reach adult services without an underlying syndromic diagnosis. For adult neurologists taking over their care, it is often unclear how hard to search for an underlying diagnosis. The diagnostic yield may be small and such a diagnosis may not change management. Young adults with learning difficulties are also challenging to investigate, as they may not tolerate standard epilepsy tests.We present such a case in which simple tests identified a unifying diagnosis. With the new diagnosis came a new treatment that had a significant impact on seizures and quality of life
Independent components of human brain morphology
Quantification of brain morphology has become an important cornerstone in understanding brain structure. Measures of cortical morphology such as thickness and surface area are frequently used to compare groups of subjects or characterise longitudinal changes. However, such measures are often treated as independent from each other. A recently described scaling law, derived from a statistical physics model of cortical folding, demonstrates that there is a tight covariance between three commonly used cortical morphology measures: cortical thickness, total surface area, and exposed surface area. We show that assuming the independence of cortical morphology measures can hide features and potentially lead to misinterpretations. Using the scaling law, we account for the covariance between cortical morphology measures and derive novel independent measures of cortical morphology. By applying these new measures, we show that new information can be gained; in our example we show that distinct morphological alterations underlie healthy ageing compared to temporal lobe epilepsy, even on the coarse level of a whole hemisphere. We thus provide a conceptual framework for characterising cortical morphology in a statistically valid and interpretable manner, based on theoretical reasoning about the shape of the cortex
Associations between cognitive impairment and patient-reported measures of physical/mental functioning in older people living with HIV
Objectives: While cognitive impairment is frequently reported in HIV-positive individuals and has historically been associated with poorer functional outcomes, the associations between cognitive impairment and patient-reported outcome measures (PROMs) in contemporary cohorts are unclear.
Methods: We tested cognitive function using a computerized battery (CogState™) in 290 HIV-positive and 97 HIV-negative individuals aged ≥ 50 years participating in the Pharmacokinetic and Clinical Observations in People Over Fifty (POPPY) study. Participants completed questionnaires detailing physical and mental health [Short Form Health Survey (SF-36)], cognitive function [European AIDS Clinical Society (EACS) questions], activities of daily living [Lawton Instrumental Activities of Daily Living (IADL)], depression [Patient Depression Questionnaire (PHQ-9) and Centres for Epidemiologic Studies Depression scale (CES-D)], falls and sexual desire. Cognitive impairment was defined using the Frascati criteria, global deficit score (GDS) and multivariate normative comparison (MNC). In the HIV-positive group, the classification performances of the different definitions of cognitive impairment and dichotomized questionnaire results were calculated.
Results: The prevalence of cognitive impairment in the HIV-positive group was 34.5% (GDS), 30.0% (Frascati) and 22.1% (MNC), with only 2% diagnosed with HIV-associated dementia. In general, the associations between cognitive impairment and PROMs were weak regardless of the definition used: mean c-statistics were 0.543 (GDS), 0.530 (MNC) and 0.519 (Frascati). Associations were similar using the global T-score to define cognitive impairment. Summary health scores (SF-36) were lower, but only significantly so for those with cognitive impairment identified using MNC, for both mental health (61.4 vs. 75.8; P = 0.03) and physical health (60.9 vs. 75.0; P = 0.03).
Conclusions: The associations between cognitive impairment and PROMs were weak, possibly because impairment was mild and therefore largely asymptomatic. Further work is needed to elucidate the clinical implications of cognitive impairment in HIV-disease
Gender Specific Brood Cells in the Solitary Bee Colletes halophilus (Hymenoptera; Colletidae)
We studied the reproductive behaviour of the solitary bee Colletes halophilus based on the variation in cell size, larval food amount and larval sex in relation to the sexual size dimorphism in this bee. Brood cells with female larvae are larger and contain more larval food than cells with males. Occasionally males are reared in female-sized cells. We conclude that a female C. halophilus in principal anticipates the sex of her offspring at the moment brood cell construction is started. Additionally a female is able to ‘change her mind’ about the sex of her offspring during a single brood cell cycle. We present a model that can predict the sex of the larvae in an early stage of development
The 'COmorBidity in Relation to AIDS' (COBRA) cohort: Design, methods and participant characteristics
BACKGROUND: Persons living with HIV on combination antiretroviral therapy (cART) may be at increased risk of the development of age-associated non-communicable comorbidities (AANCC) at relatively young age. It has therefore been hypothesised that such individuals, despite effective cART, may be prone to accelerated aging. OBJECTIVE: The COmorBidity in Relation to AIDS (COBRA) cohort study was designed to investigate the potential causal link between HIV and AANCC, amongst others, in a cohort of middle-aged individuals with HIV with sustained viral suppression on cART and otherwise comparable HIV-negative controls. METHODS: Longitudinal cohort study of HIV-positive subjects ≥45 years of age, with sustained HIV suppression on cART recruited from two large European HIV treatment centres and similarly-aged HIV-negative controls recruited from sexual health centres and targeted community groups. Both HIV-positive and HIV-negative subjects were assessed at study entry and again at follow-up after 2 years. RESULTS: Of the 134 HIV-positive individuals with a median (IQR) age of 56 (51, 62) years recruited, 93% were male, 88% of white ethnicity and 86% were men who have sex with men (MSM). Similarly, the 79 HIV-negative subjects had a median (IQR) age of 57 (52, 64) and 92% were male, 97% of white ethnicity and 80% were MSM. CONCLUSIONS: The results from the COBRA study will be a significant resource to understand the link between HIV and AANCC and the pathogenic mechanisms underlying this link. COBRA will inform future development of novel prognostic tools for earlier diagnosis of AANCC and of novel interventions which, as an adjunct to cART, may prevent AANCC
Independent components of human brain morphology
Quantification of brain morphology has become an important cornerstone in
understanding brain structure. Measures of cortical morphology such as
thickness and surface area are frequently used to compare groups of subjects or
characterise longitudinal changes. However, such measures are often treated as
independent from each other.
A recently described scaling law, derived from a statistical physics model of
cortical folding, demonstrates that there is a tight covariance between three
commonly used cortical morphology measures: cortical thickness, total surface
area, and exposed surface area.
We show that assuming the independence of cortical morphology measures can
hide features and potentially lead to misinterpretations. Using the scaling
law, we account for the covariance between cortical morphology measures and
derive novel independent measures of cortical morphology. By applying these new
measures, we show that new information can be gained; in our example we show
that distinct morphological alterations underlie healthy ageing compared to
temporal lobe epilepsy, even on the coarse level of a whole hemisphere.
We thus provide a conceptual framework for characterising cortical morphology
in a statistically valid and interpretable manner, based on theoretical
reasoning about the shape of the cortex
Invasive lobular carcinoma of the breast presenting as retroperitoneal fibrosis: a case report
<p>Abstract</p> <p>Introduction</p> <p>Invasive lobular carcinoma of the breast represents approximately 6.3% of mammary malignancies. Distant metastasis of invasive lobular carcinoma to the peritoneum or retroperitoneum has been reported fairly frequently.</p> <p>Case presentation</p> <p>We report the case of a 59-year-old Caucasian-Canadian woman with invasive lobular carcinoma of the breast presenting with retroperitoneal fibrosis and bilateral ureteral obstruction. Intra-operative pathology consultation did not reveal malignancy. The diagnosis, however, was confirmed on permanent sections by histological appearance in addition to immunohistochemistry. To the best of our knowledge, this is the first reported case of invasive lobular carcinoma of the breast presenting with retroperitoneal fibrosis.</p> <p>Conclusion</p> <p>In a case of unexplained ureteric obstruction and retroperitoneal fibrosis, more comprehensive physical examination and additional ancillary studies may be warranted to rule out malignancy as an underlying etiology. This case also emphasizes that intra-operative frozen section consultation cannot always be fully relied upon to exclude a malignancy as the etiology of retroperitoneal fibrosis. Moreover, in permanent histopathology sections, immunohistochemistry testing can be of value to rule out metastatic disease where the morphology is not salient. There is a need for a thorough physical examination of patients with retroperitoneal fibrosis, including the breast and gynecological organs.</p
The role of mast cells in the pathogenesis of pain in chronic pancreatitis
BACKGROUND: The biological basis of pain in chronic pancreatitis is poorly understood. Mast cells have been implicated in the pathogenesis of pain in other conditions. We hypothesized that mast cells play a role in the pain of chronic pancreatitis. We examined the association of pain with mast cells in autopsy specimens of patients with painful chronic pancreatitis. We explored our hypothesis further using an experimental model of trinitrobenzene sulfonic acid (TNBS) -induced chronic pancreatitis in both wild type (WT) and mast cell deficient mice (MCDM). METHODS: Archival tissues with histological diagnoses of chronic pancreatitis were identified and clinical records reviewed for presence or absence of reported pain in humans. Mast cells were counted. The presence of pain was assessed using von Frey Filaments (VFF) to measure abdominal withdrawal responses in both WT and MCDM mice with and without chronic pancreatitis. RESULTS: Humans with painful chronic pancreatitis demonstrated a 3.5-fold increase in pancreatic mast cells as compared with those with painless chronic pancreatitis. WT mice with chronic pancreatitis were significantly more sensitive as assessed by VFF pain testing of the abdomen when compared with MCDM. CONCLUSION: Humans with painful chronic pancreatitis have an increased number of pancreatic mast cells as compared with those with painless chronic pancreatitis. MCDM are less sensitive to mechanical stimulation of the abdomen after induction of chronic pancreatitis as compared with WT. Mast cells may play an important role in the pathogenesis of pain in chronic pancreatitis
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