Hypothalamus-pituitary-adrenal hyperactivity in human aging is partially refractory to stimulation by mineralocorticoid receptor blockade

CONTEXT: The hypothalamus-pituitary-adrenal (HPA) axis is mainly regulated by CRH, arginine vasopressin, and glucocorticoid feedback. Hippocampal mineralocorticoid receptors mediate proactive glucocorticoid feedback and mineralocorticoid antagonists, accordingly, stimulate HPA axis. Age-related HPA hyperactivity reflects impaired glucocorticoid feedback at the suprapituitary level. DESIGN: ACTH, cortisol, and dehydroepiandrosterone (DHEA) secretion were studied in eight healthy elderly (75.1 +/- 3.2 yr) and eight young (25.0 +/- 4.6 yr) subjects during placebo or canrenoate (CAN) administration (200 mg i.v. bolus followed by 200 mg infused over 4 h). RESULTS: During placebo administration, ACTH and cortisol areas under the curve (AUCs) in elderly subjects were higher than in young subjects (P < or = 0.01); conversely, DHEA AUCs in elderly subjects were lower than in young subjects (P = 0.002). CAN increased ACTH, cortisol, and DHEA levels in both groups. In young subjects, ACTH, cortisol, and DHEA levels at the end of CAN infusion were higher (P < or = 0.05) than after placebo. In elderly subjects, at the end of CAN infusion, ACTH, cortisol, and DHEA levels were higher (P = 0.01) than after placebo. Under CAN, ACTH and cortisol AUCs were persistently higher (P < or = 0.01) and DHEA AUCs lower (P = 0.006) in elderly than in young subjects. Cortisol AUCs after CAN in young subjects did not become significantly different from those in elderly subjects after placebo. CONCLUSIONS: 1) Evening-time ACTH and cortisol secretion in elderly subjects is higher than in young subjects; 2) ACTH and cortisol secretion in elderly subjects is enhanced by CAN but less than that in young subjects; and 3) DHEA hyposecretion in elderly subjects is partially restored by mineralocorticoid antagonism. Age-related variations of HPA activity may be determined by some derangement in mineralocorticoid receptors function at the hippocampal level.     

Re-immunisation schedule in leukaemic children after intensive chemotherapy: a possible strategy

The aim of this retrospective study was to test the residual humoral immunity to compulsory vaccines after the end of chemotherapy for acute lymphoblastic leukaemia in a cohort of 70 Italian children. All the patients, who had been immunised according to the Italian schedule prior to the disease, were tested for antibody levels against tetanus and hepatitis B at a median of 10 months after the end of therapy. Median age at diagnosis of leukaemia was 48 months, and median age at vaccine titration was 84 months. The protective level of antibodies for tetanus and hepatitis B was shown in 83% and 81% of patients, respectively; the remaining 17% and 19% were not protected against the two pathogens. Double negativity was observed in only four of 62 (6%) patients in the cohort. These data were comparable with published data regarding healthy children of the same age and from the same geographical areas. Therefore, given the direct and indirect costs of performing laboratory tests, as well as the cost of revaccination, our proposal is to continue the vaccination schedule according to the child's age without any titration screening 6 months after the end of therapy. Larger studies are needed to confirm these observations.     

Imaging of brain serotonergic neurotransmission involving phospholipase A2 activation and arachidonic acid release in unanesthetized rats

In vitro studies have shown that 5-HT2 receptors can be coupled via G-proteins to phospholipase A2 (PLA2) activation, releasing arachidonic acid from phospholipids. To examine this signaling pathway in brain, we developed an in vivo method to image regional brain PLA2 activation in unanesthetized rats given different types of serotonergic drugs. Increased arachidonate incorporation from plasma, in response to drug-induced PLA2-activation, can be quantified with autoradiography, following the intravenous injection of radiolabeled arachidonate. For example, a 5-HT(2A/2C) receptor agonist, (+/-)-2,5-dimethoxy-4-iodophenyl-2-aminopropane, produced widespread increases in incorporation of labeled arachidonate by directly binding to 5-HT(2A/2C) receptors. Fluoxetine, a selective serotonin reuptake inhibitor, selectively increased incorporation of arachidonic acid by increasing 5-HT availability in the synaptic cleft and thus indirectly activating phospholipase A2. The detailed method is described.     

Blood-nerve barrier in the frog during wallerian degeneration: Are axons necessary for maintenance of barrier function?

Blood-nerve barrier tissues (endoneurial blood vessels and perineurium) of the frog's sciatic nerve were studied during chronic Wallerian degeneration to determine whether barrier function depends on the presence of intact axons. Sciatic nerves of adult frogs were transected in the abdominal cavity; the ends were tied to prevent regeneration and the distal nerve stumps were examined. Vascular permeabilities to horseradish peroxidase and to [14C]sucrose increased to day 14, returned toward normal levels by 6 weeks, and continued at near normal levels to 9 months. Perineurial permeabilities to the tracers increased by day 10 and remained elevated at 9 months. Proliferation of perineurial, endothelial, and mast cells occurred between 3 days and 6 weeks, resulting in an increased vascular space (measured with [3H]dextran) and number of vascular profiles. The perineurium increased in thickness and the mast cells increased in number. This study indicates that during Wallerian degeneration of the frog's sciatic nerve there is 1) a transitory increase in vascular permeability distal to the lesion, that is related to changes within the endoneurium; 2) an irreversible increase in permeability of the perineurium, which begins later than that seen in the endoneurial blood vessels; and 3) proliferation of non-neuronal components in the absence of regenerating neuronal elements. The results indicate that maintenance of vascular integrity does not require the presence of axons in the frog's peripheral nerve, whereas perineurial integrity and barrier function are affected irreversibly by Wallerian degeneration.     

Cyst infection in hospital-admitted autosomal dominant polycystic kidney disease patients is predominantly multifocal and associated with kidney and liver volume

Positron-emission tomography/computed tomography (PET/CT) has improved cyst infection (CI) management in autosomal dominant polycystic kidney disease (ADPKD). The determinants of kidney and/or liver involvement, however, remain uncertain. In this study, we evaluated clinical and imaging factors associated with CI in kidney (KCI) and liver (LCI) in ADPKD. A retrospective cohort study was performed in hospital-admitted ADPKD patients with suspected CI. Clinical, imaging and surgical data were analyzed. Features of infected cysts were evaluated by PET/CT. Total kidney (TKV) and liver (TLV) volumes were measured by CT-derived multiplanar reconstruction. CI was detected in 18 patients who experienced 24 episodes during an interval of 30 months (LCI in 12, KCI in 10 and concomitant infection in 2). Sensitivities of CT, magnetic resonance imaging and PET/CT were 25.0, 71.4, and 95.0%. Dysuria (P<0.05), positive urine culture (P<0.01), and previous hematuria (P<0.05) were associated with KCI. Weight loss (P<0.01) and increased C-reactive protein levels (P<0.05) were associated with LCI. PET/CT revealed that three or more infected cysts were present in 70% of the episodes. TKV was higher in kidney-affected than in LCI patients (AUC=0.91, P<0.05), with a cut-off of 2502 mL (72.7% sensitivity, 100.0% specificity). TLV was higher in liver-affected than in KCI patients (AUC=0.89, P<0.01) with a cut-off of 2815 mL (80.0% sensitivity, 87.5% specificity). A greater need for invasive procedures was observed in LCI (P<0.01), and the overall mortality was 20.8%. This study supports PET/CT as the most sensitive imaging method for diagnosis of cyst infection, confirms the multifocal nature of most hospital-admitted episodes, and reveals an association of kidney and liver volumes with this complication.     

Role of ultrasonography in the management of patients with primary hyperparathyroidism: retrospective comparison with technetium-99m sestamibi scintigraphy

Objective

Primary hyperparathyroidism (PHPT) is a common endocrine disorder that can be cured only by parathyroidectomy. Cervical ultrasonography and scintigraphy are the imaging studies most widely used for preoperative localization of the affected glands. The aim of this retrospective comparative study was to define the respective roles of ultrasonography and parathyroid scintigraphy in these cases.

Materials and methods

We analyzed 108 patients who had undergone parathyroidectomies for PHPT following cervical ultrasonographic and scintigraphic examinations. The ultrasound examinations were carried out by an expert physician sonographer in 61 cases and by various physician sonographers with different levels of experience in 47 cases. Sonographic and scintigraphic findings were compared with surgical findings and the diagnostic performance of the two imaging methods was evaluated by means of statistical analysis.

Results

The operator dependency of ultrasonography was confirmed by marked variations in sensitivity related to the experience of the sonographer. When sonography was performed by an expert, the sensitivity of combined use of the two methods was not significantly higher than that of sonography alone.

Conclusions

In expert hands, the diagnostic yield of ultrasound is appreciably superior. It can therefore be used as the main and possibly sole method for preoperative localization of pathological parathyroid tissues. Combined use of ultrasound and scintigraphy is not cost-effective in these cases. Scintigraphy is indicated only when the ultrasound examination produces negative results.     

Consequences of ABO incompatibility in multiple myeloma patients undergoing peripheral blood stem cell transplantation after reduced intensity conditioning

Background

Although the ABO blood group is one of two major antigen systems of relevance for transplantation in humans, there are still conflicting data concerning the influence of ABO-incompatibility on transplant outcome. This study investigated the effect of ABO incompatibility in recipients of haematopoietic progenitor cell transplants from related donors after reduced intensity conditioning (RIC) regimens.

Materials and Methods

We retrospectively analysed data from 19 multiple myeloma patients included in a prospective RIC allogeneic haematopoietic progenitor cell transplantation protocol, focusing on engraftment, transfusion requirement, Graft-versus-Host Disease, transplant-related mortality and survival.

Results

Five out of the 19 patients (26%) received an ABO-incompatible transplant, with minor ABO-mismatch in two patients (10%), major ABO-mismatch in one case (5%), and bidirectional incompatibility in two cases. Neutrophil recovery was not significantly different between the ABO-compatible and ABO-incompatible groups (p=0.85). At 30 days after transplantation, 12 of 19 patients tested (63%) had engraftment with all cells of donor origin (100% chimeric), and continued to be fully chimeric on day 100+ evaluations. Patients with major/bidirectional ABO incompatibility required more red blood cell and platelet units after transplantation and were transfused for longer periods of time, as compared with patients with minor or no ABO incompatibility. Transient, mild haemolysis was noted in one patient between days 10 and 30. Graft-versus-Host Disease, disease progression and transplant-related mortality were not affected by ABO matching.

Discussion

Although delayed red blood cell engraftment and increased transfusion requirements were documented, in this study ABO incompatibility after the RIC protocol used did not impair the clinical outcome.     

Grandparenting,education and subjective well-being of older Europeans

We study whether grandparenthood is associated with older people’s subjective well-being (SWB), considering the association with life satisfaction of having grandchildren per se, their number, and of the provision of grandchild care. Older people’s education may not only be an important confounder to control for, but also a moderator in the relation between grandparenthood-related variables and SWB. We investigate these issues by adopting a cross-country comparative perspective and using data from the Survey of Health, Ageing and Retirement in Europe covering 20 countries. Our results show that grandparenthood has a stronger positive association with SWB in countries where intensive grandparental childcare is not common and less socially expected. Yet, this result is driven by a negative association between grandparenthood without grandparental childcare and SWB that we only found in countries where intensive grandparental childcare is widespread. Therefore, in accordance with the structural ambivalence theory, we argue that in countries where it is socially expected for grandparents to have a role as providers of childcare, not taking on such a role may negatively influence SWB. However, our results show that grandparental childcare (either intensive or not) is generally associated with higher SWB. Overall, we do not find support for a moderating effect of education. We also do not find striking differences by gender in the association between grandparenthood and SWB. The only noteworthy discrepancy refers to grandmothers being often more satisfied when they provide grandchild care.