Coping and psychological distress among symptomatic HIV+ men who have sex with men

This study evaluated relations among indicators of latent coping factors and psychological distress while incorporating measures of life stress and HIV illness related factors simultaneously among 211 symptomatic, HIV+ men who have sex with men (MSM). Participants were all assessed at a single time point. A structural equations model with latent factors for approachoriented coping, avoidant-oriented coping, and psychological distress showed adequate fit. Furthermore, significant associations were identified among latent factors for approach-oriented coping, avoidance coping, and psychological distress; specifically, greater use of approach-oriented coping strategies and less use of avoidant-oriented coping were associated with lower levels of psychological distress. The model was revised to incorporate variables significantly associated with psychological distress (i.e., personal loss-total events, personal loss-controllability, and HIV-related symptoms). Relations among the coping and psychological distress latent factors remained significant. The results suggest that HIV+ MSM who do not have the coping skills or resources necessary to use adequate coping strategies to face the chronic burdens associated with HIV illness are likely to experience higher levels of psychological distress, independent of life stress and ongoing HIV-related symptoms. This work was supported by grants from the National Institute of Mental Health, including PO1 MH49548, and T32 MH18917.     

Determination of cystathionine beta-synthase activity in human plasma by LC-MS/MS: potential use in diagnosis of CBS deficiency

Cystathionine β-synthase (CBS) deficiency is usually confirmed by assaying the enzyme activity in cultured skin fibroblasts. We investigated whether CBS is present in human plasma and whether determination of its activity in plasma could be used for diagnostic purposes. We developed an assay to measure CBS activity in 20 μL of plasma using a stable isotope substrate - 2,3,3-²H serine. The activity was determined by measurement of the product of enzyme reaction, 3,3-²H-cystathionine, using LC-MS/MS. The median enzyme activity in control plasma samples was 404 nmol/h/L (range 66–1,066; n = 57). In pyridoxine nonresponsive CBS deficient patients, the median plasma activity was 0 nmol/ho/L (range 0–9; n = 26), while in pyridoxine responsive patients the median activity was 16 nmol/hour/L (range 0–358; n = 28); this overlapped with the enzyme activity from control subject. The presence of CBS in human plasma was confirmed by an in silico search of the proteome database, and was further evidenced by the activation of CBS by S-adenosyl-L-methionine and pyridoxal 5′-phosphate, and by configuration of the detected reaction product, 3,3-²H-cystathionine, which was in agreement with the previously observed CBS reaction mechanism. We hypothesize that the CBS enzyme in plasma originates from liver cells, as the plasma CBS activities in patients with elevated liver aminotransferase activities were more than 30-fold increased. In this study, we have demonstrated that CBS is present in human plasma and that its catalytic activity is detectable by LC-MS/MS. CBS assay in human plasma brings new possibilities in the diagnosis of pyridoxine nonresponsive CBS deficiency.     

Neuronal cytoskeletal lesions induced in the CNS by intraventricular and intravenous aluminium maltol in rabbits

The antigenicity of neuronal cytoskeletal lesions was studied immunohistochemically in adult New Zealand white rabbits after intraventricular (subacute) and intravenous (chronic) administration of a water-soluble aluminium compound, aluminium (Al) maltol. After short-term intraventricular administration, rabbits developed widespread neurofibrillary degeneration (NFD) involving pyramidal neurons of the isocortex and allocortex, projection neurons of the diencephalon, and nerve cells of the brain stem and spinal cord. There was a predilection for motor neuron involvement and for the infratentorial portions of the neuraxis. Perikarya and proximal neurites were especially affected. Bundles of 10 nm filaments were frequently present. Three of the animals treated intravenously for 12 weeks or longer displayed NFD in the oculomotor complex and in the pyramidal neurons of the occipital isocortex. Following either mode of administration, the affected neurons exhibited immunostaining with a panel of monoclonal antibodies (MAbs) against phosphorylated (SMI-31), non-phosphorylated/phosphatase-sensitive (SMI-32), and dephosphorylation-independent (SMI-33) epitopes of high and middle molecular weight neurofilament (NF) protein subunits. They were non-reactive with MAbs to microtubule-associated protein 2 and the class III neuron-associated beta-tubulin isotype. Our findings indicate that intraventricular Al maltol produces similar, but more widespread degeneration of projection-type neurons than the less water-soluble Al compounds as reported by others. The NFD lesions are compared with those of senile dementia of the Alzheimer type (SDAT) and motor neuron disease.     

拓扑替康对人子宫内膜癌细胞株AN3CN抑制作用的研究

目的观察拓扑替康(TPT)对人子宫内膜癌细胞株AN3CN生长的抑制作用及TPT对诱导肿瘤细胞调亡的作用。方法共分为5组,对照组不加TPT,治疗组根据所加TPT浓度的不同分为20μgL组、40μgL组、80μgL组及160μgL组。MTT法检测各组在不同时间经TPT处理后的肿瘤细胞抑制率,流式细胞术检测各组细胞经TPT处理24小时后的细胞周期变化,电子显微镜观察各组肿瘤细胞形态学改变。结果治疗组不同浓度的TPT对AN3CN细胞的生长均有抑制作用,其中40μgL组和80μgL组随药物作用的延长,肿瘤抑制率也显著增大,各治疗组G0G1期的细胞比例数增加,S期和G2M期细胞减少,其中40μgL组、80μgL组和160μgL组与对照组差异显著(P<005),各治疗组的细胞在形态学上呈细胞调亡的表现。结论TPT对子宫内膜癌细胞株AN3CN的生长具有抑制作用,并且诱导肿瘤细胞调亡是TPT抗肿瘤作用的机理之一。     

Peroneal muscle activity during different types of walking

Background

As the most common form of movement, walking happens not only on flat but also on uneven surfaces, where constant loss and regaining of balance occur. The main balancing function of the ankle joint is performed by tibial muscles. When changing inclination in a frontal plane, an essential balancing function is performed by the peroneal muscles. One of the methods for improving the activity of peroneal muscles is walking with different foot placement. The objective of this study was to analyze the activity of the peroneal muscles when performing different types of walking.

Methods

Sixteen healthy participants took part in this study, walking on a flat surface (NORM), on a medial incline ramp with the plantar surface of the foot fully placed on the surface (FULL), and on a medial incline ramp with elevated lateral part of the foot (LAT). We monitored the changes of EMG signals in peroneus longus (PL), peroneus brevis (PB), tibialis anterior (TA), soleus (SOL), gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) muscles. We monitored kinematic parameters (gait speed, stride length, contact time, foot position). The parametric ANOVA test and a non-parametric Friedman test were used at an alpha level of 0.05.

Results

This study shows that the EMG activities of peroneal muscles increases when walking on the medial incline ramp. Statistically significant EMG differences were observed in the peroneal muscles, TA and GL muscles. We observe a very high percentage of normalized EMG value of the PL muscle in LAT walking. Walking on a medial incline ramp impacts the foot position, contact time, and stride length but not the gait speed.

Conclusions

Walking on a medial incline ramp could be an effective exercise to improve the neuro-muscular function of the peroneal muscles and, therefore, might be a suitable exercise for people with weakened ankle evertors.