Repeated Valsalva maneuvers promote symptomatic manifestations of cerebral microhemorrhages: implications for the pathogenesis of vascular cognitive impairment in older adults

Multifocal cerebral microhemorrhages (CMHs, also known as “cerebral microbleeds”), which are associated with rupture of small intracerebral vessels, have been recognized as an important cause for cognitive decline in older adults. Although recent studies demonstrate that CMHs are highly prevalent in patients 65 and older, many aspects of the pathogenesis and clinical significance of CMHs remain obscure. In this longitudinal observational study, a case of a 77-year-old man with multifocal CMHs is described, in whom the rupture of intracerebral vessels could be linked to repeatedly performing extended Valsalva maneuvers. This patient was initially seen with acute aphasia after performing a prolonged Valsalva maneuver during underwater swimming. T2-weighted magnetic resonance imaging revealed a left acute frontal intracerebral hemorrhage (ICH) with multiple CMHs. The aphasia was resolved and no cognitive impairment was present. Two years later, he developed unsteadiness and confusion after performing two prolonged Valsalva maneuvers during underwater swimming separated by about 12 days. Repeat brain imaging revealed an acute right and a subacute left ICH, with a marked interval increase in the number of CMHs. The patient also exhibited manifest memory loss after the second admission and was diagnosed with dementia. These observations suggest that prolonged Valsalva maneuver is potentially a common precipitating cause of both CMHs and symptomatic ICHs. The Valsalva maneuver both increases the systolic arterial pressure and gives rise to a venous pressure wave transmitted to the brain in the absence of the competent antireflux jugular vein valves. This pressure increase is superimposed on existing hypertension and/or increases in blood pressure due to exercise and increased venous return due to immersion of the body in water. We advocate that further studies are needed to distinguish between CMHs with arterial and venous origins and their potential to lead to ICH induced by Valsalva maneuver as well as to determine whether these lesions have a predilection for a particular location.     

Allergen immunotherapy decreases specific allergen-induced expression of Fas and FasL on CD4+ and CD8+ cells.

Apoptosis programmed cell death without induction of an inflammatory response. It is mediated by Fas--a cell surface protein which is expressed on activated lymphocytes. Interaction with its counterpart--the Fas ligand induces the apoptosis of Fas bearing cells. The mechanism underlying successful immunotherapy has not been identified. The aim of this study was to investigate whether specific immunotherapy (SIT) might affect Fas and FasL expression after stimulation with specific allergen. The study was conducted on 8 allergic subjects and 8 healthy volunteers as controls. The allergic patients were treated with conventional SIT (Pollinex). Blood samples were collected before the first day and 7 days after the last injection. Isolated CD4+ and CD8+ cells were incubated in various concentrations of specific allergen (1, 10, 100 ng/ml) or in medium alone. Indirect immunofluorescence test with rabbit IgG against human Fas and FasL was performed. The percentage of positive cells was determined under fluorescence microscope. The expression of Fas and FasL before SIT was significantly increased on CD4+ and CD8+ cells under the influence of specific allergen (10, 100 ng/ml). After SIT, significant decrease in the expression of both molecules was observed, although elimination of allergen-reactive cells was not complete and their number was still higher than in the controls. CONCLUSION: The exposure of CD4+ and CD8+ cells on allergen may induce the Fas-FasL apoptotic pathway. Significant decrease in number of allergen-reactive CD4+, CD8+ cells after SIT suggests participation of the phenomenon in deletion of clones, which may be a part of the allergen tolerance mechanism achieved naturally or during SIT.     

Medicine taking behaviours of people with type 2 diabetes in Indonesia: a qualitative study

International Journal of Clinical Pharmacy - Background Medicine-taking behaviour of people in Indonesia is particularly complex because of Indonesia’s pluralistic health system, in which...     

Return of the lysergamides. Part VI: Analytical and behavioural characterization of 1‐cyclopropanoyl‐d‐lysergic acid diethylamide (1CP‐LSD)

Lysergic acid diethylamide (LSD) is a prototypical serotonergic psychedelic drug and the subject of many clinical investigations. In recent years, a range of lysergamides has emerged with the production of some being inspired by the existing scientific literature. Others, for example various 1‐acyl substituted lysergamides, did not exist before their appearance as research chemicals. 1‐Cylopropanoyl‐LSD (1CP‐LSD) has recently emerged as a new addition to the group of lysergamide‐based designer drugs and is believed to be psychoactive in humans. In this investigation, 1CP‐LSD was subjected to detailed analytical characterizations including various mass spectrometry (MS) platforms, gas and liquid chromatography, nuclear magnetic resonance spectroscopy, solid phase and GC condensed phase infrared spectroscopy. Analysis by GC–MS also revealed the detection of artificially induced degradation products. Incubation of 1CP‐LSD with human serum led to the formation of LSD, indicating that it may act as a prodrug for LSD in vivo, similar to other 1‐acyl substituted lysergamides. The analysis of blotters and pellets is also included. 1CP‐LSD also induces the head‐twitch response (HTR) in C57BL/6 J mice, indicating that it produces an LSD‐like behavioural profile. 1CP‐LSD induced the HTR with an ED₅₀ = 430.0 nmol/kg which was comparable to 1P‐LSD (ED₅₀ = 349.6 nmol/kg) investigated previously. Clinical studies are required to determine the potency and profile of the effects produced by 1CP‐LSD in humans.     

Broad and potent neutralizing human antibodies to tick-borne flaviviruses protect mice from disease

Tick-borne encephalitis virus (TBEV) is an emerging human pathogen that causes potentially fatal disease with no specific treatment. Mouse monoclonal antibodies are protective against TBEV, but little is known about the human antibody response to infection. Here, we report on the human neutralizing antibody response to TBEV in a cohort of infected and vaccinated individuals. Expanded clones of memory B cells expressed closely related anti-envelope domain III (EDIII) antibodies in both groups of volunteers. However, the most potent neutralizing antibodies, with IC₅₀s below 1 ng/ml, were found only in individuals who recovered from natural infection. These antibodies also neutralized other tick-borne flaviviruses, including Langat, louping ill, Omsk hemorrhagic fever, Kyasanur forest disease, and Powassan viruses. Structural analysis revealed a conserved epitope near the lateral ridge of EDIII adjoining the EDI–EDIII hinge region. Prophylactic or early therapeutic antibody administration was effective at low doses in mice that were lethally infected with TBEV.     

The Effect of Standard Versus Longer Intestinal Bypass on GLP-1 Regulation and Glucose Metabolism in Patients With Type 2 Diabetes Undergoing Roux-en-Y Gastric Bypass: The Long-Limb Study

OBJECTIVERoux-en-Y gastric bypass (RYGB) characteristically enhances postprandial levels of glucagon-like peptide 1 (GLP-1), a mechanism that contributes to its profound glucose-lowering effects. This enhancement is thought to be triggered by bypass of food to the distal small intestine with higher densities of neuroendocrine L-cells. We hypothesized that if this is the predominant mechanism behind the enhanced secretion of GLP-1, a longer intestinal bypass would potentiate the postprandial peak in GLP-1, translating into higher insulin secretion and, thus, additional improvements in glucose tolerance. To investigate this, we conducted a mechanistic study comparing two variants of RYGB that differ in the length of intestinal bypass.RESEARCH DESIGN AND METHODSA total of 53 patients with type 2 diabetes (T2D) and obesity were randomized to either standard limb RYGB (50-cm biliopancreatic limb) or long limb RYGB (150-cm biliopancreatic limb). They underwent measurements of GLP-1 and insulin secretion following a mixed meal and insulin sensitivity using euglycemic hyperinsulinemic clamps at baseline and 2 weeks and at 20% weight loss after surgery.RESULTSBoth groups exhibited enhancement in postprandial GLP-1 secretion and improvements in glycemia compared with baseline. There were no significant differences in postprandial peak concentrations of GLP-1, time to peak, insulin secretion, and insulin sensitivity.CONCLUSIONSThe findings of this study demonstrate that lengthening of the intestinal bypass in RYGB does not affect GLP-1 secretion. Thus, the characteristic enhancement of GLP-1 response after RYGB might not depend on delivery of nutrients to more distal intestinal segments.     

Cardiovascular and Renal Disease Burden in Type 1 Compared With Type 2 Diabetes: A Two-Country Nationwide Observational Study

OBJECTIVEType 1 diabetes (T1D) and type 2 diabetes (T2D) increase risks of cardiovascular (CV) and renal disease (CVRD) compared with diabetes-free populations. Direct comparisons between T1D and T2D are scarce. We examined this by pooling full-population cohorts in Sweden and Norway.RESEARCH DESIGN AND METHODSA total of 59,331 patients with T1D and 484,241 patients with T2D, aged 18–84 years, were followed over a mean period of 2.6 years from 31 December 2013. Patients were identified in nationwide prescribed drug and hospital registries in Norway and Sweden. Prevalence and event rates of myocardial infarction (MI), heart failure (HF), stroke, chronic kidney disease (CKD), all-cause death, and CV death were assessed following age stratification in 5-year intervals. Cox regression analyses were used to estimate risk.RESULTSThe prevalence of CV disease was similar in T1D and T2D across age strata, whereas CKD was more common in T1D. Age-adjusted event rates comparing T1D versus T2D showed that HF risk was increased between ages 65 and 79 years, MI between 55 and 79 years, and stroke between 40 and 54 years (1.3–1.4-fold, 1.3–1.8-fold, and 1.4–1.7-fold, respectively). CKD risk was 1.4–3.0-fold higher in T1D at all ages. The all-cause death risk was 1.2–1.5-fold higher in T1D at age >50 years, with a similar trend for CV death.CONCLUSIONSAdult patients with T1D compared with those with T2D had an overall greater risk of cardiorenal disease (HF and CKD) across ages, MI and all-cause death at middle-older ages, and stroke at younger ages. The total age-adjusted CVRD burden and risks were greater among patients with T1D compared with those with T2D, highlighting their need for improved prevention strategies.