Oxyhemoglobin changes in the prefrontal cortex in response to cognitive tasks: a systematic review

Purpose of the study: the aim of this study was to synthesize PFC fNIRS outcomes on the effects of cognitive tasks compared to resting/baseline tasks in healthy adults from studies utilizing a pre/post design.

Material and methods: original research studies were searched from seven databases (MEDLINE, EMBASE, CENTRAL, CINAHL, SCOPUS, PEDro and PubMed). Subsequently, two independent reviewers screened the titles and abstracts followed by full-text reviews to assess the studies' eligibility.

Results: eleven studies met the inclusion criteria and had data abstracted and quality assessed. Methodology varied considerably and yet cognitive tasks resulted in the ΔO₂Hb increasing in 8 of the 11 and ΔHHb decreasing in 8 of 8 studies that reported this outcome. The cognitive tasks from 10 of the 11 studies were classified as “Working Memory” and “Verbal Fluency Tasks”.

Conclusions: although, the data comparison was challenging provided the heterogeneity in methodology, the results across studies were similar.     

Multi-center analysis of calcinosis in children with juvenile dermatomyositis]

OBJECTIVES: To reveal the frequency and the clinical characteristics of dystrophic calcification that occurs in children with juvenile dermatomyositis, multi-center analysis was constructed. METHOD: Fifty children with JDM were enrolled, and 14 of them (28.0%) were complicated with calcinosis. Clinical symptoms and laboratory tests at onset, initial therapy and disease course were compared in children with and without calcinosis. RESULTS: The mean age of the onset of calcinosis was 4.78 +/- 3.33 years, and it was younger than those of children without calcinosis (8.66 +/- 3.85 years) (P = 0.0017). No differences of clinical manifestation except Gower's sign were observed. The frequency of positive anti-nuclear antibody was 7.1% in children with calcinosis and 52.9% without calcinosis (P = 0.0112). The initial therapy of methylprednisolon pulses gave no effects on prognosis of calcium deposition. The calcinosis appeared in 1.56 +/- 1.91 year after the onset of the disease. The various types of calcium deposition including large tumorous clumps, subcutaneous plaques or nodules, sheet-type calcification were deserved. They appeared over knee joints (64.3%), elbow joint (64.3%), and hip processes (50.0%). Calcinosis affecting the subcutaneous tissues frequently resulted in painful superficial ulceration of the overlying skin (42.9%), local infection (50.0%), and limitation of joint movement (14.3%). Although aluminum phosphate was effective in 2 children among 7, no other effective treatment was recommended. In 5 cases, surgical removal of tumorous clumps was operated. Thus, juvenile dermatomyositis is frequently complicated with calcinosis. This type of calcinosis was found to be unlikely to resolve completely, and resulted in severe disability in children.     

Prediction of remission in Graves' disease after thionamide therapy by technetium-99m early uptake]

In the clinical management of Graves' thyrotoxicosis, one of the most important subject is when to stop antithyroid drugs after achieving an euthyroid state. T3 suppression test and other methods have been used to forecast the outcome after drug cessation, but the results were not always satisfactory. We have attempted to predict remission of Graves' disease by single measurement of early technetium uptake without administration of triiodothyronine. Drugs were discontinued in the seventy-five patients with Graves' disease on maintenance doses of either methimazole or propylthiouracil who showed normalized uptake (4.0% or less). Of 64 patients evaluable after twelve months, 55 (86%) remained euthyroid, 8 relapsed, and 1 became hypothyroid. With its accuracy in prediction of short-term remission comparable or superior to T3 suppression test, this rapid and simple method seemed suitable for routine use in clinical practice.     

Congenitally corrected transposition of the great arteries associated with the pre-excitation syndrome

A case with congenitally corrected transposition of the great arteries associated with the pre-excitation syndrome is presented. A gated-blood-pool study and Tl-201 myocardial imaging were performed using SPECT. The tomographic gated-blood-pool images showed the shapes of the right ventricle (RV) and left ventricle (LV), i.e., anatomically LV and RV respectively, to be reversed from that of normal patients. The relationships of the great vessels and ventricles also were easily visualized. RV hypertrophy (anatomical LV) was visualized on the Tl-201 images. Phase analysis showed the earliest excitation was in the anteroseptal region near the base of the LV, which was consistent with the site of the accessory conduction pathway. The gated-blood-pool and Tl-201 tomographic studies were helpful for demonstrating the corrected transposition of the great arteries and the pre-excitation syndrome.     

Endocannabinoids and synaptic function in the CNS.

Marijuana affects neural functions through the binding of its active component (Delta(9)-THC) to cannabinoid receptors in the CNS. Recent studies have elucidated that endogenous ligands for cannabinoid receptors, endocannabinoids, serve as retrograde messengers at central synapses. Endocannabinoids are produced on demand in activity-dependent manners and released from postsynaptic neurons. The released endocannabinoids travel backward across the synapse, activate presynaptic CB1 cannabinoid receptors, and modulate presynaptic functions. Retrograde endocannabinoid signaling is crucial for certain forms of short-term and long-term synaptic plasticity at excitatory or inhibitory synapses in many brain regions, and thereby contributes to various aspects of brain function including learning and memory. Molecular identities of the CB1 receptor and enzymes involved in production and degradation of endocannabinoids have been elucidated. Anatomical studies have demonstrated unique distributions of these molecules around synapses, which provide morphological bases for the roles of endocannabinoids as retrograde messengers. CB1-knockout mice exhibit various behavioral abnormalities and multiple defects in synaptic plasticity, supporting the notion that endocannabinoid signaling is involved in various aspects of neural function. In this review article, the authors describe molecular mechanisms of the endocannabinoid-mediated synaptic modulation and its possible physiological significance.     

Immunological Detection and Quantitation of DNA Adducts Formed by 4-Aminoazobenzene Species in vivo

Antibodies to 3-methoxy-4-aminoazobenzene (3-MeO-AAB) and 2-methoxy-4-aminoazobenzene (2-MeO-AAB) DNA adducts were raised in rabbits against in vitro-adducted DNA samples. The enzyme-linked immunosorbent assay (ELISA) was used to determine the sensitivity and specificity of these antibodies. They proved highly specific for the modified DNA used as the immunogen, but cross-reacted with each other. Moreover, they showed cross reactivity with DNA modified by 4-( o -tolylazo)- o -toluidine, but not by other carcinogens, such as 4-aminobiphenyl or 4-nitroquinoline 1-oxide. The 50% inhibition level of antibody binding in the competitive ELISA was at 10–20 fmol of modified base per assay (equivalent to 1–2 adducts per 10⁶ bases). Immunohistochemical staining indicated that these antibodies bind specifically to nuclear components of the liver in rats given either 3-MeO-AAB or 2-MeO-AAB at the dose of 50 mg/kg body weight.     

Correlation between inflammatory cellular responses and chemotactic activity in bronchoalveolar lavage fluid following intratracheal instillation of nickel sulfate in rats

In a preceding study, we reported that the numbers of macrophages and polymorphonuclear leukocytes (PMN) were increased in bronchoalveolar lavage fluid (BALF) following the intratracheal instillation of nickel sulfate (NiSO₄) in rats. In the present study, BALF chemotactic activities for both macrophages and PMN were measured to investigate if the increases of these inflammatory cells in BALF depend on increases in chemotactic activities in epithelial lining fluid (ELF) of the lung. Both the number of PMN and the PMN chemotactic activity peaked at 2 days post-instillation and they were significantly correlated. However, the PMN chemotactic activity was inversely correlated with concentration of leukotriene B₄ (LTB₄), a well-known chemotaxin. Although PMN were not observed in control BALF, LTB₄ concentration in the control ELF (ca. 5×10^–7 M) was estimated to have a potential to attract PMN chemotactically through a membrane in in vitro migration assay. These results suggest that the presence of LTB₄ in ELF itself does not trigger transpulmonary PMN infiltration. The rat BALF were fractionated by high performance liquid chromatography (HPLC), and PMN chemotactic activity of each fraction was measured. The elution profiles of PMN chemotactic activity showed that there were at least two different chemotaxins in BALF obtained from the NiSO₄-exposed rats. Macrophage chemotactic activity in BALF also peaked at 2 days post-instillation. However, the number of macrophages was not significantly correlated with the chemotactic activity for macrophage in BALF. The HPLC study showed that the macrophage chemotactic substance in the BALF obtained from NiSO₄-exposed rats was different from complement fragment (C5a) and its MW was estimated to be 10 – 12 kD. Received: 1 December 1993/Accepted: 16 March 1994     

Comparison of lidocaine with and without bupivacaine for local dental anesthesia.

The purpose of this study was to investigate the effectiveness of a combination of bupivacaine and lidocaine and that of lidocaine alone for local dental anesthesia. First, on different days, healthy volunteers were given 2% lidocaine with 1/80,000 epinephrine or 2% lidocaine with 1/80,000 epinephrine + 0.5% bupivacaine, after which pain was produced with a pulp tester. No difference was found in the time until onset of anesthetic effect between the preparations. However, the duration of anesthetic effect was longer with both lidocaine and bupivacaine than with lidocaine alone. Next, patients undergoing dental surgery were given one of the anesthetic preparations, after which serum concentrations of the anesthetics and epinephrine were measured. The maximal serum concentration of lidocaine was higher and was reached sooner after injection in patients receiving lidocaine alone (1.74 microgram/ml after 5 min) than in patients receiving both anesthetics (0.85 microgram/ml after 3 min). The mean maximal serum concentration of lidocaine was higher in patients receiving lidocaine alone (1.77 +/- 0.03 microgram/ml) than in those receiving both anesthetics (0.99 +/- 0.45 microgram/ml). Furthermore, the mean plasma concentration of epinephrine 1 min after injection was significantly higher in patients receiving lidocaine alone (0.671 ng/ml) than in patients receiving both lidocaine and bupivacaine (0.323 ng/ml). The results of this study suggest that the combination of lidocaine with epinephrine and bupivacaine produces lower systemic levels of the anesthetic and epinephrine and a longer duration of activity than lidocaine with epinephrine alone for local dental anesthesia.