Demonstration of an atypical pre- ß-lipoprotein in human serum

An atypical pre-β-lipoprotein of human serum has been detected by agarose gel electrophoresis in four patients, three of whom were siblings. This lipoprotein differed from the pre-β lipoprotein previously observed with this technique by sedimenting on ultracentrifugation at density 1.006.     

Antibody reactivity in penicillin-sensitive patients determinated with different penicillin derivatives.

35 individuals showing reactions to penicillin of anaphylactic shock, angioedema or urticaria were investigated. Their skin sensitivity was analysed using 16 different penicillin derivatives. In addition, the content of circulating reagins against the penicilloyl structure in the patient's sera were analysed using RAST. 17 of the patients had negative skin reactions and RAST results to all substances tested. The other 18 were skin test-positive to at least one derivative but showed markedly heterogeneous patterns of skin reactivity. 14 had positive reactions against penicilloyl structures accompanied by anti-penicilloyl reagins. Four patients showed doubtful reactions only to penicillin or penicilloate and/or penilloate. These patients also had very low levels of reagins against penicilloyl in their sera. Positive skin test results using monovalent penicillin derivatives such as penicillin, penicilloate, penilloate, penicilloyl amide, penicilloyl-formyl-lysine, penicillamine, which cannot form a multivalent antigen with penicillyol specificity, indicated formation of other derivatives of importance in penicillin allergy, e.g., penicillamine protein conjugates. Three patients showed skin reactions to ampicillin polymer and two to benzyl-penicillin polymer. The skin tests performed with the penicillin derivatives used do not seem to give more information on the sensitivity of the patients than does the RAST using penicilloyl structures.     

Chronic Social Stress in the Community and Associations with Psychological Distress: A Social Psychological Perspective

Chronic social stress is strongly related to psychological distress in vulnerable groups such as the frail elderly and ill people. Little, however, is known about these phenomena in the general population. The validity and reliability of a new brief measure, the Bergen Social Relationships Scale (BSRS), were investigated in a Norwegian county; the prevalence of chronic social stress was measured using the BSRS, and the associations of chronic social stress and social support with three measures of psychological distress were investigated. Respondents with high BSRS scores had experienced longstanding, important interpersonal relationship problems rather than fleeting stressful incidents. Women reported higher levels of chronic social stress, 60% reporting positively on at least one of the six BSRS items, compared with 50% among men. Social support was negatively and significantly associated with various measures of psychological distress. Chronic social stress was positively and significantly associated with psychological distress. These effects were independent of one another. No buffering effect of social support on social stress was observed. The present data support the importance of positive social ties to health, but suggest that social stress is an independent aspect of social environment with regard to health. If social support and social stress have direct and independent effects on mental health, as the present results indicate, intervention on the one will not necessarily modify the other. Intervention programmes may need to consider explicitly both the lighter and the darker sides of social relationships in building environments that support mental health.     

Bilateral corticospinal projections arise from each motor cortex in the macaque monkey: a quantitative study

The corticospinal projection is considered to influence fine motor function through nearly exclusively contralateral projections from the cortex in primates. However, unilateral lesions to this system in various species are frequently followed by significant functional improvement, raising the possibility that bilateral projections of this pathway may exist or emerge after injury. To examine the detailed anatomy and projections of the corticospinal motor neurons in rhesus monkeys (n = 4), we injected the high-resolution anterograde tracer biotinylated dextran amine (BDA) into 126 sites centered about the right lower extremity (LE) primary motor cortex. Projection and termination patterns were quantified at lumbar levels L1, L4, and L7 and mapped by using serial-section reconstructions. Notably, a mean of 10.1 +/- 0.6% (+/- SEM) of corticospinal tract (CST) axons descended in the lateral CST ipsilateral to the cortical BDA injection, and 87.9 +/- 1.0% of total CST axons projected in the contralateral lateral CST. The ipsilateral ventral CST contained only 1.0 +/- 0% of all projecting CST axons, whereas the contralateral ventral CST contained 0.3 +/- 0.2% of all axons. In addition, a minor dorsal column CST projection was identified. Measurement of BDA-labeled terminals in the spinal cord gray matter revealed that 11.2 +/- 2.2% of CST axons terminated ipsilateral to the side of cortical injection, and the remainder terminated contralaterally. As previously reported, most CST axons terminated in spinal cord laminae V-VIII, as well as the laterodorsal motoneuronal group of lamina IX (which innervates distal extremity muscles). Notably, many CST axons crossed the spinal cord midline (mean 19.9 +/- 4.9 axons per 40-microm-thick section). Detailed single-axon reconstructions revealed that most ipsilaterally projecting lateral CST axons terminated in ipsilateral gray matter. Notably, we found that the bouton-like swellings of many ipsilateral CST axons descending in the dorsolateral tract were located within Rexed's lamina IX, in close proximity to motoneuronal somata. Thus, bilateral projections of corticospinal axons originating from a single motor cortex could contribute to bilateral control of spinal motor neurons and to the highly evolved degree of fine motor control in primates. Furthermore, bilateral CST projections from a single motor cortex could represent a potential source of plasticity after injury, as well as a target of therapeutic effort in neural regeneration strategies.     

Electroconvulsive Therapy Effects on Cerebrospinal Fluid Monoamine Metabolites and Platelet Serotonin Uptake In Melancholia

The effects of ECT on 5-hydroxyindoleacetic acid, homovanillic acid (HVA), and 4-hydroxy-3-methoxyphenylglycol in cerebrospinal fluid and on kinetic parameters of platelet serotonin uptake were studied in 12 patients with melancholia. There were no significant changes in the monoamine metabolites 3 weeks after initiation of ECT in 12 patients; however, there was a tendency for HVA to increase. The V(max) of serotonin uptake (measured in seven patients) remained unchanged after ECT, but there was a significant increase in K(m), indicating a decreased affinity for serotonin in the carrier.     

Blood pressure reduction does not reduce perihematoma oxygenation: a CT perfusion study

Blood pressure (BP) reduction after intracerebral hemorrhage (ICH) is controversial, because of concerns that this may cause critical reductions in perihematoma perfusion and thereby precipitate tissue damage. We tested the hypothesis that BP reduction reduces perihematoma tissue oxygenation.Acute ICH patients were randomized to a systolic BP target of <150 or <180 mm Hg. Patients underwent CT perfusion (CTP) imaging 2 hours after randomization. Maps of cerebral blood flow (CBF), maximum oxygen extraction fraction (OEF^max), and the resulting maximum cerebral metabolic rate of oxygen (CMRO₂^max) permitted by local hemodynamics, were calculated from raw CTP data.Sixty-five patients (median (interquartile range) age 70 (20)) were imaged at a median (interquartile range) time from onset to CTP of 9.8 (13.6) hours. Mean OEF^max was elevated in the perihematoma region (0.44±0.12) relative to contralateral tissue (0.36±0.11; P<0.001). Perihematoma CMRO₂^max (3.40±1.67 mL/100 g per minute) was slightly lower relative to contralateral tissue (3.63±1.66 mL/100 g per minute; P=0.025). Despite a significant difference in systolic BP between the aggressive (140.5±18.7 mm Hg) and conservative (163.0±10.6 mm Hg; P<0.001) treatment groups, perihematoma CBF was unaffected (37.2±11.9 versus 35.8±9.6 mL/100 g per minute; P=0.307). Similarly, aggressive BP treatment did not affect perihematoma OEF^max (0.43±0.12 versus 0.45±0.11; P=0.232) or CMRO₂^max (3.16±1.66 versus 3.68±1.85 mL/100 g per minute; P=0.857). Blood pressure reduction does not affect perihematoma oxygen delivery. These data support the safety of early aggressive BP treatment in ICH.     

Reference values for ultrasonograpy of peripheral nerves

Introduction: High‐resolution ultrasonography (HRU) is a novel method that provides morphological information about peripheral nerves. We aimed to determine reference values for nerve cross‐sectional area (CSA) on HRU. Methods: One hundred healthy volunteers had HRU of median, radial, ulnar, fibular, tibial, sural, and superficial fibular nerves at defined sites. The CSA was measured and the effects of age, gender, and body mass index (BMI) were evaluated. Results: CSA values in healthy subjects are described. CSA is larger in lower limb motor nerves than in sensory nerves at similar sites, and the CSA tends to be symmetrical. The strongest effect on CSA was for age, although gender and BMI had some effects. Conclusions: This study provides normative values for HRU, and it suggests that further research with age‐ and gender‐specific distributions must be a key priority in the development of HRU for use as a diagnostic test for peripheral nerve diseases. Muscle Nerve 53 : 538–544, 2016     

Arterial concentration of 99mTc-sestamibi at rest, during peak exercise and after dipyridamole infusion

Tracers for myocardial perfusion imaging during stress should not only have high cardiac uptake but they should also have a fast blood clearance to prevent myocardial tracer uptake after the ischaemic stimulus. The present study characterize the early phase of the arterial (99m)Tc-sestamibi (MIBI) time-activity curve after venous bolus injection at rest, during peak exercise and after dipyridamole infusion. We included 11 patients undergoing angioplasty for one-vessel disease (rest study) and 20 patients evaluated for the detection of haemodynamic significant coronary stenoses by (99m)Tc-sestamibi single photon emission computed tomography (SPECT) using either bicycle exercise testing (10 patients) or standard dipyridamole testing (10 patients). Arterial blood samples of 1 ml were taken from the left femoral artery (rest study) or the right radial artery (exercise and dipyridamole studies) every 5 s during the first 5 min postinjection. In the exercise and the dipyridamole studies blood sampling were extended to include blood samples every 5 min 5-30 min postinjection. Peak MIBI concentration was lower and decrease in concentration slower after tracer injection during exercise than during dipyridamole stress testing. This may cause an underestimation of perfusion defects during exercise because of MIBI uptake after the ischaemic stimulus. The implications of the study not only refer to the choice of stress modality when using MIBI. This study also underlines the importance of considering early blood clearance in addition to regional myocardial tracerkinetic aspects such as myocardial extraction fraction when new tracers are introduced.     

Circulating ionized calcium and parathyroid hormone levels following coronary artery by-pass surgery

In critically ill patients, hypocalcaemia is a common finding. Also variable derangements in the normally tight Ca2+-mediated control of the parathyroid hormone (PTH) secretion have been found. Utilizing coronary artery by-pass grafting (CABG) as a standardized model of severe trauma, 18 patients underwent determinations of blood levels of calcium, magnesium (Mg), ionized calcium (Ca2+), serum levels of intact PTH, procalcitonin (PCT) and the proinflammatory cytokines tumour necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6). Samples were collected before, directly after, the morning after and 5 days after surgery. A significant, but minor, decrease in blood Ca2+ levels (mean 0.04 mmol/L, p<0.05) was seen shortly after CABG, not accompanied by any significant change of serum PTH levels. This alteration of the Ca2+ control of the steady-state PTH levels contrasted with the maintenance of the PTH secretory response to a sequential citrate and calcium infusion (CiCa clamp), which was normal in two patients evaluated in the morning following surgery. Serum Mg levels were transiently increased after operation (+0.25 mmol/L, p<0.001) and correlated to the TNF-alpha (r=0.62, p <0.01) and PCT (r=0.67, p < 0.006) levels in the morning after surgery. Serum levels of IL-6 and TNF-alpha were significantly (p < 0.0001) increased immediately after surgery, while the peak in serum PCT levels (p < 0.001) occurred in the morning after CABG. Serum PTH levels correlated positively with IL-6 (r=0.68, p<0.008) 5 days after surgery. In conclusion, CABG caused a decrease in ionized calcium levels without a rise in steady-state PTH levels, but rapid changes in Ca2+ during CiCa clamping revealed a normal PTH secretory response. These findings might relate to elevated serum Mg levels, while a direct action of TNF-alpha or IL-6 on the PTH release seem less possible.     

Analysis of 1 year virtual histology changes in coronary plaque located behind the struts of the everolimus eluting bioresorbable vascular scaffold

Serial intravascular ultrasound virtual histology (IVUS-VH) after implantation of metallic stents has been unable to show any changes in the composition of the scaffolded plaque overtime. The everolimus-eluting ABSORB scaffold potentially allows for the formation of new fibrotic tissue on the scaffolded coronary plaque during bioresorption. We examined the 12?month IVUS-VH changes in composition of the plaque behind the struts (PBS) following the implantation of the ABSORB scaffold. Using IVUS-VH and dedicated software, the composition of the PBS was analyzed in all patients from the ABSORB Cohort B2 trial, who were imaged with a commercially available IVUS-VH console (s5i system, Volcano Corporation, Rancho Cordova, CA, USA), immediately post-ABSORB implantation and at 12?month follow-up. Paired IVUS-VH data, recorded with s5i system, were available in 17 patients (18 lesions). The analysis demonstrated an increase in mean PBS area (2.39?±?1.85?mm(2) vs. 2.76?±?1.79?mm(2), P?=?0.078) and a reduction in the mean lumen area (6.37?±?0.90?mm(2) vs. 5.98?±?0.97?mm(2), P?=?0.006). Conversely, a significant decrease of 16 and 30% in necrotic core (NC) and dense calcium (DC) content, respectively, were evident (median % NC from 43.24 to 36.06%, P?=?0.016; median % DC from 20.28 to 11.36%, P?=?0.002). Serial IVUS-VH analyses of plaque located behind the ABSORB struts at 12-month demonstrated an increase in plaque area with a decrease in its NC and DC content. Larger studies are required to investigate the clinical impact of these findings.