Interplay of circulating leptin and obesity in cognition and cerebral volumes in older adults.

We aimed to investigate whether circulating leptin and body mass index (BMI) associate independently with cognitive function (decline) and brain volumes using magnetic resonance imaging (MRI) in older individuals at risk of cardiovascular disease. We studied the cross-sectional and longitudinal associations in participants enrolled in the PROSPER study (Prospective Study of Pravastatin in the Elderly at Risk). Cognitive function was tested at baseline and repeated during a mean follow-up time of 3.2 years. Analyses were performed with multivariable (repeated) linear regression models and adjusted for demographics, cardiovascular risk-factors, and stratified by sex. We included 5623 dementia-free participants (52 % female, mean age 75 years) with a mean BMI of 26.9 (SD = 4.1). In a sub-study, 527 participants underwent brain MRI. At baseline, individuals with a BMI > 30 had a worse performance on the Stroop test (ß 5.0 s, 95 %CI 2.6;7.5) and larger volumes of the amygdala (ß 234 mm3, 95 %CI 3;464) and hippocampus (ß 590 mm3, 95 %CI 181;999), independent of intracranial volume and serum leptin levels, compared with individuals with the reference BMI (BMI 18-25 kg/m2). Per log ng/mL higher serum leptin, independent of BMI, a 135 mm3 (95 %CI 2;268) higher volume of the amygdala was found, but no association was observed with cognitive tests nor with other brain volumes. Stratification for sex did not materially change the results. Whereas higher BMI associated with worse cognitive function independent of leptin levels, our study provided evidence that leptin and BMI independently associate with amygdala volume suggesting potential distinct biological associations.

Vasculitis and rheumatologic diseases may play role in the pathogenesis of acute disseminated encephalomyelitis (ADEM).

Acute disseminated encephalomyelitis (ADEM) is defined as a multifocal, monophasic, demyelinating, and inflammatory disease involving the central nervous system. It typically begins within 6 weeks of an antigenic challenge such as infection or immunization. Perivenous inflammation, edema and demyelination are the pathological hallmarks of ADEM. Reactivity of T-cells against myelin components such as myelin basic protein has been found in children with ADEM. The triggers for immune responses in ADEM are not known, but the two most widely accepted hypotheses are molecular mimicry and self-sensitization secondary to CNS infection. Inflammatory cytokines including tumor necrosis factor alpha (TNFalpha), interleukin 2 (IL2) and interferon gamma (INFgamma) are thought to be important in lesion formation in ADEM. Due to the active role of inflammatory cytokines in the pathogenesis of ADEM, any disease contributing to systemic formation of inflammatory cytokines can potentially be an etiologic factor for the initiation of ADEM. In vasculitis and rheumatologic diseases the number of T-cells, T helper type 1 cytokines and other inflammatory cytokines such as TNFalpha increase substantially. We present this hypothesis that in such setting of inflammation, adhesion molecules are up-regulated on the brain capillary endothelium by cytokines and other inflammatory mediators, altering the permeability of the brain blood barrier and so allowing for inflammatory cell migration. The migratory cells attack the basic myelin protein and the final result is the demyelination seen in ADEM. So we propose that vasculitis and rheumatologic diseases may play role in the pathogenesis of ADEM.

A postulated role of testosterone for prevention of cisplatin gonadal toxicity.

Testicular cancer is the most common solid tumor in young men. It has become one of the most curable solid neoplasms by applying multidisciplinary treatment approaches and new chemotherapeutic drugs. Cisplatin based chemotherapy as the most efficient chemotherapy of germ cell tumors has severe deleterious effects on all stages of spermatogenesis by various direct and indirect mechanisms. By marked improvement in oncologic control, prognosis and survival of patients with testicular cancer, their fertility, as one of the essential aspects of quality of life, is a matter of great concern. Since the probability and severity of spermatogenesis impairment is quite unpredictable during a course of cisplatin based chemotherapy, protecting the spermatogenesis during that phase by administration of exogenous testosterone in order to reduce the proliferation rate of germ cells would seem to be beneficial.