Effects by doxorubicin on the myocardium are mediated by oxygen free radicals

We hypothesized that doxorubicin (DOX) induces cardiotoxicity of myocardium via oxygen radicals. The present study is aimed at examining the membrane alterations by oxygen radicals generated by DOX in adult rats and cultured neonatal myocytes. Our results showed that DOX 1) decreased beta-adrenoceptor (BAR) density in the cell membrane, 2) increased the membrane permeability of cultured neonatal rat myocytes and 3) altered the ultrastructure of myofibrils and subplasmalemmal actin networks. These effects were reproducible by exogenous hydrogen peroxide. The antioxidant melatonin (MLT) inhibited enzyme leakage and peroxidation in a concentration-dependent manner. It is concluded that DOX induces cardiotoxicity through lipid peroxidation and melatonin is an effective antioxidant against the reactive oxygen intermediates generated by DOX.

Polysaccharide peptide (PSP) restores immunosuppression induced by cyclophosphamide in rats

Polysaccharide peptide (PSP) is a protein-bound polysaccharide extracted from an edible mushroom, Coriolus versicolor. Effects of PSP (2g/kg/day) on cyclophosphamide (CPA, 40 mg/kg/2 days)-induced immunosuppression were investigated by determining lymphocyte proliferation, Natural killer (NK) cell formation, IgG and IL-2 concentration, WBC count and the weight of organs after rats were treated with or without CPA in the presence or absence of PSP. The results demonstrated that PSP possessed immunopotentiating effect, being effective in restoring CPA-induced immunosuppression such as depressed lymphocyte proliferation, Natural Killer cell function, production on white blood cell and the growth of spleen and thymus in rats as well as in increasing both IgG and IL-2 production on which CPA did not have significant effects under the conditions of our experiments. PSP can partly restore CPA-induced immunosuppression. Based on our findings and the data accumulated so far, it was suggested that PSP should be considered as an useful adjuvant especially combined with CPA or other chemotherapy in clinical treatment of cancer patients. The mechanism by which PSP restores the immunosuppression induced by CPA is unclear.

Melatonin protects against cardiac toxicity of doxorubicin in rat

Doxorubicin (DOX) is commonly used for the treatment of hematological and solid tumors. However, there are serious toxic effects on the cardiovascular system, which limits the application of the drug. Recently, melatonin has been reported to have immunomodulatory effect in addition to lowering cholesterol levels as well as inhibiting malignant tumors. In this study, the effect of melatonin against the toxicity of doxorubicin was investigated in rats. Hemodynamic function, pathological and biochemical changes were determined in different treated hearts. Our findings showed that a significant protection by melatonin (6 mg kg(-1) for 15 days, cumulative dose of 90 mg kg(-1)) against the DOX-induced toxicity was observed. Cardiac function was improved and lipid peroxidation decreased after melatonin treatment. It is concluded that melatonin provides protection against doxorubicin toxicity via an attenuation of lipid peroxidation.

A two-year study of acceptability, side effects, and effectiveness of Norplant and Norplant-2 implants in the People's Republic of China

A large scale, phased investigation of NORPLANT contraceptive systems was conducted in the People's Republic of China. The first phase comprehended 1,200 women in four cities. Expanded trials included 11,918 women at 12 major centers and at sub-centers by 31 May 1987. At that date 4,676 NORPLANT capsule subjects and 1,089 rod subjects had completed one year of use, 1,381 capsule acceptors had completed two years as had 197 rod users. Gross pregnancy rates were less than 0.1 per 100 for each implant type both at one and at two years. Continuation rates were 94 per 100 for each implant type at one year, and were 82.0 and 83.6 per 100 among users of NORPLANT capsule and rod implants, respectively, at two years. Disruption of menstrual function was the dominant reason for termination, but mean hemoglobin levels increased in each of the nine centers reporting values at admission and at one year. First year gross cumulative termination rates for medical reasons were 1.2 to 1.3 per 100, reaching 3.8 and 5.6 per 100 for capsule and rod implants, respectively, at two years. Microdose contraception with these levonorgestrel-releasing implants appears to be a highly acceptable and effective modality suitable for Chinese women. NORPLANT implants are now approved by the national drug regulatory agency for general use in China.

Superoxide dismutase does protect the cultured rat cardiac myocytes against hypoxia/reoxygenation injury

The effect of superoxide dismutase (SOD) on membrane integrity and fluidity of the cultured neonatal rat cardiac myocytes in vitro was investigated under the condition of hypoxia and hypoxia/reoxygenation. Lactate dehydrogenase (LDH) concentration was used as the biochemical indicator for the loss of cell membrane integrity. Fluorescence polarization (FP), average microviscosity (eta) and anisotropy (Ast), which are inversely proportional to the fluidity of cell membrane, were assayed. Cells were respectively exposed to hypoxia or hypoxia/reoxygenation for different periods of time in the absence or presence of SOD at various concentrations. Hypoxia alone or hypoxia/reoxygenation brought injury to the cultured myocytes. This was demonstrated by changes in LDH and membrane fluidity. In the former LDH concentration gradually increased in a time-dependent manner and the values of FP, eta and Ast were significantly increased. The changes in membrane integrity and fluidity induced by hypoxia or hypoxia/reoxygenation could be prevented by adding SOD to the culture medium. The results provide a direct evidence that SOD (740 u.ml-1, the effective dose) was effective in protecting cultured myocytes against the injury as well as an indirect evidence of free radical generation. Based on the results obtained from this study and the establishment of concept of optimally effective dose by Bernier and Omar et al, it was suggested that some previous reports, in which no evidence was found both in protective effect of SOD and in free radical generation by using only one dose in hypoxia/reoxygenation model, should be interpreted with caution.

Differential behaviour of cell membranes towards iron-induced oxidative damage and the effects of melatonin

The ability of melatonin to protect iron-induced lipid peroxidation was studied in various rat cell membranes. The concentration of cellular membrane malondialdehyde (MDA) was used as an index of induced oxidative membrane damage. Cell membranes from the brain, heart, kidney and liver of the male Sprague-Dawley rat were incubated with ferric ammonium citrate (20 microg/ml iron) alone for 3 h and concomitant with varying concentrations of melatonin ranging from 125 to 2,000 microM. The basal MDA levels of all the cell membranes were 25.0+/-1.4 (brain), 21.2+/-0.2 (heart), 10.0+/-0.9 (kidney) and 20.7+/-0.4 (liver) microM/g membrane protein, and the highest lipid peroxidation after exposure to iron occurred in the kidney (314.4%), followed by the heart (151.3%), the liver (130.4%) and the brain (121.7%). This peroxidative effect was completely (ED50 846.7 microM for the heart) and partially suppressed by melatonin (ED50 462.1 microM for the brain, 178.3 microM for the kidney and 886.6 microM for the liver). This inhibition effect on MDA production by these cell membranes was also found - except for the liver - if melatonin was used alone. These results show that the direct effect of lipid peroxidation on cellular membrane following iron exposure is markedly reduced by melatonin.

Super-resolution imaging for infrared micro-scanning optical system

The image super-resolution (SR) reconstruction technology based on the micro-scanning system is one of the best methods for realizing high-resolution infrared imaging. Thus, in this work, we first present a frequency domain phase-based projection onto convex sets SR reconstruction algorithm. This method takes advantage of the texture details and contrast-independent feature of the phase information in the frequency domain and can be used to realize image denoising and SR reconstruction for the infrared image simultaneously. We also propose the use of an image quality assessment metric based on the frequency domain phase spectrum. Second, we design and realize an infrared micro-scanning optical system to obtain sub-pixel low-resolution images for SR reconstruction. The infrared micro-scanning optical system we constructed can realize controllable sub-pixel micro-scanning of an arbitrary step size. Furthermore, we can realize sub-pixel low-resolution image collection by moving two light and compact pieces instead of moving the entire lens, sensor array, or sample-as in the traditional method. Thus, the precision of the sub-pixel movements can be greatly improved. Using our proposed algorithm and infrared micro-scanning optical system, we realize infrared SR imaging in both simulations and experiments.

[Tuberculous otomastoiditis presenting as hydrotympanum: one case report]

Summary To study the clinical features, diagnosis and treatments of tuberculous otomastoiditis. One case is reported and literatures are reviewed. In this report, the specimen of the middle ear revealed the presence of acid fast bacilli（AFB）, grew mycobacterium tuberculosis on a culture. Lung CT scans demonstrated tuberculosis. After anti-tuberculosis therapy, the symptoms disappeared and did not recur in 3 years. Hydrotympanum can be the early symptom of tuberculous otomastoiditis. When persistent otorrhea can not be improved by conventional therapy, tuberculous otomastoiditis should be considered as one of the differential diagnosis.

Link of gray matter volume to cognitive and motor function in elderly patients with mild cognitive impairment

BACKGROUND

Mild cognitive impairment (MCI) is a transitional state between normal aging and Alzheimer's disease (AD), characterized by subtle cognitive decline. Amnestic MCI (aMCI), in particular, is a critical precursor often progressing to AD. There is growing interest in understanding the neuroanatomical correlates of aMCI, especially the role of gray matter volume (GMV) in cognitive and motor function decline. This study hypothesized that aMCI patients will exhibit reduced GMV, particularly in brain regions associated with cognition and motor control, impacting both cognitive performance and motor abilities.

AIM

To investigate the association of GMV with cognitive and motor functions in aMCI.

METHODS

In this cross-sectional study conducted from March 2022 to March 2024, 45 aMCI patients and 45 normal controls from our Department of Geratology were enrolled. Voxel-based morphometry was used to compare GMV between groups. Correlation of differential GMV with cognitive scores and gait parameters was assessed via partial correlation analysis. Linear regression was used to assess associations between whole-brain GMV and gait measures.

RESULTS

GMV of aMCI region of interest (ROI) 1 and ROI2 was negatively correlated with Activities of Daily Living (ADL) score. GMV of ROI6 was positively correlated with the total scores of Mini-Mental State Examination and Cambridge Cognitive Examination-Chinese Version (CAMCOG-C) and negatively correlated with ADL score. In the partial correlation analysis of cognitive and motor function parameters, age, gender, educational level, height, and weight were controlled, and the results showed that CAMCOG-C was negatively correlated with Dual Task of Time Up and Go Test (TUG) duration in the aMCI group. The volume of the left occipital gray matter in the aMCI group was negatively correlated with TUG. GMV of the bilateral frontal gyrus, right orbitofrontal gyrus, right occipital cleft, right supraoccipital gyrus, and left anterior central gyrus was positively correlated with walking speed.

CONCLUSION

GMV reduction in aMCI correlates with impaired cognition and motor function, emphasizing key roles for prefrontal, occipital, and central regions in gait disorders.

[Effects of superoxide dismutase on ischemic reperfusion injury in isolated working heart and cultured myocardial cells of rats]

An isolated working rat heart underwent 40 min of normothermic ceasing perfusion and 25 min of reperfusion. Superoxide dismutase (SOD) or/and mannitol were added to the perfusate 15 min before ceasing perfusion and 15 min after reperfusion. The results indicate that SOD (37,000 IU/L) improved significantly the contractile function of heart and increased the aortic output and coronary flow. Mannitol 0.02 mol/L provided additional benefit. The rat myocardial cells were cultured in the medium for 3 h with hypoxia followed by 2 h of reoxygenation. The content of lactic dehydrogenase (LDH) in the medium was increased and the degree of fluorescence polarization of myocardial cell membrane was raised. SOD was effective in preventing LDH release and decreasing the degree of fluorescence polarization. These results clearly demonstrate that ischemic reperfusion are capable of causing significant myocardial injury, which can be reduced or prevented by administration of oxygen free radical scavenger SOD.

[Histopathology appearance of intrauterine residue after medical abortion by mifepristone and prostaglandin analogue]

Four hundred and fifty pregnant women were recruited for termination of early gestation by mifepristone combined with dl-15-methyl PGF2 alpha or misoprostol. Eight-four out of 450 subjects received curettage because of heavy or prolonged vaginal bleeding and slow decline of urinary hCG levels. Histopathology examinations of specimens obtained during curettage revealed denatured, necrotic and obscure villi and trophoblasts in 77 specimens, which accounted for 91.7%. Among them, 68 samples were mingled with inflammatory cell infiltration, and 15 with decidual cells, only 3 were villi and trophoblasts alone. The remaining 7 specimens were decidua in 6 and inflammatory infiltration in 1, which accounted for 7.1% and 1.2% respectively. This study suggested that the major cause resulting in heavy or prolonged vaginal bleeding after medical abortion by mifepristone and prostaglandin analogue was residual villi and trophoblasts with inflammatory cell infiltration.

[Research on NIR-CI parameters optimization of chlorpheniramine maleate tablets based on binary image and statistical measurement]

The optimization method was established to investigate the effect of near infrared chemical imaging (NIR-CI) detection parameters on hyperspectral data quality. In order to optimize the detection parameters, chlorpheniramine maleate (CPM) tablets were chosen as examples and the L9(3(4)) orthogonal-test design was adopted to research the effects of spectral resolution, spatial resolution, scan times and scan height. Binary image coupled with statistical measurement was proposed to quantitatively analyze hyperspectral data and determine the content of CPM on the tablet surface. High-performance liquid chromatography (HPLC) was used as reference method for accurate CPM determination. The absolute value of the difference between CPM con- tents obtained from NIR-CI and HPLC was chosen as index. The result demonstrated that the optimum parameters for acquiring hyperspectral data were: 25 μm x 25 μm (spatial resolution), 5340 (scan height, the value of Z, precise focus), 16 cm(-1) (spectral resolution) and 16 (scan times). The influence of scan height on hyperspectral data was firstly investigated. The optimized parameters could be applied to CPM tablets and other drugs for NIR-CI data acquisition and methodology establishment.