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41.
Summary The in vitro effect of zinc on superoxide anion (O2?) generation and on experimentally induced lipid peroxidation (LPO) in spermatozoa of infertile men was investigated. Washed spermatozoa pre-incubated for 30 min at 37°C in the presence of 1 or 3 mmol l-1 zinc, released less superoxide anions (P<0.03 and P<0.02, respectively; n=9) than the untreated spermatozoa. Similar results were obtained using activated polymorphonuclear leukocytes (1 times 106 cells ml-1) in the presence of 1 or 3 mmol l-1 Zn (P<0.001 and P<0.0002, respectively; n=9). The in vitro evidence of the inhibitory effect of zinc on O2? generation by human spermatozoa and leukocytes indicates that zinc may act in vivo as a scavenger of excessive O2? production by defective spermatozoa and/or leukocytes in semen after ejaculation. A significant stimulatory effect of Zn (3 mmol l-1) on iron-induced lipid peroxidation, measured by the formation of thiobarbituric acid reactive substances (TBARS), was detected in the spermatozoa of 16 normo- and 17 asthenozoospermic males (P<0.0001 and P<0.001, respectively). In 11 samples with sperm concentration 20.3±2.1 times 106 ml-1, exhibiting initial TBARS concentration two times higher than in normo-and asthenozoospermic samples (40.5±2.4 vs. 17.1±1.1 and 28.5±4.1 nmoles TBARS 10-8 spermatozoa), no effect of zinc on the LPO rate was found. The observed inhibitory effect of zinc on superoxide anion regardless of the initial O2? level and stimulatory effect of zinc depending on the initial LPO rate in human spermatozoa suggests that this metal ion participates in the oxidative changes occurring after ejaculation and thus may modulate the properties of germ cells. 相似文献
42.
William E. Gillies FRACS FRACO FRCS Anne MV Brooks MD PhD FRACS FRACO FRACP 《Clinical & experimental ophthalmology》1996,24(3):169-187
Background: We have investigated the vascular perfusion of a wide variety of conditions of the anterior segment using fluorescein angiography.
Methods: The conditions were classified and findings reported according to the system set out below. Patients underwent full ocular examination. Fluorescein angiography of the anterior segment was carried out when indicated to investigate iris atrophy and neovascularisation. Specular microscopy of the corneal endothelium was used to detect changes in this tissue.
Results: The hypoperfusion was variable in degree and accompanied by varying degrees of iris hypoplasia and atrophy with neovascularisation. The degree of neovascularisation depended upon its rapidity of development, the pre-existing state of vascular perfusion and the underlying pathological condition.
Conclusions: Hypoperfusion with resultant ischaemia and neovascularisation is common in conditions of the anterior segment. An understanding of the changes is valuable in treating many conditions affecting the anterior segment. The changes observed may also occur elsewhere in the physical system and may be a significant part of the ageing process, either as scattered, disparate processes or as part of a general disease process. 相似文献
Methods: The conditions were classified and findings reported according to the system set out below. Patients underwent full ocular examination. Fluorescein angiography of the anterior segment was carried out when indicated to investigate iris atrophy and neovascularisation. Specular microscopy of the corneal endothelium was used to detect changes in this tissue.
Results: The hypoperfusion was variable in degree and accompanied by varying degrees of iris hypoplasia and atrophy with neovascularisation. The degree of neovascularisation depended upon its rapidity of development, the pre-existing state of vascular perfusion and the underlying pathological condition.
Conclusions: Hypoperfusion with resultant ischaemia and neovascularisation is common in conditions of the anterior segment. An understanding of the changes is valuable in treating many conditions affecting the anterior segment. The changes observed may also occur elsewhere in the physical system and may be a significant part of the ageing process, either as scattered, disparate processes or as part of a general disease process. 相似文献
43.
Intermittent administration of low doses of human parathyroid hormone (h-PTH) has been reported to exhibit an anabolic effect
on bone, increasing its mass. We investigated the effects of intermittent administration of h-PTH on bone changes in streptozotocin-
(STZ-) induced diabetes mellitus (DM) rats by measuring bone mineral density and bone mineral contents and by bone histomorphometry.
Wistar rats, 7–8 months old, were used. Osteoporosis was induced by diabetes mellitus, which was established by an intraperitoneal
injection of STZ. Rats were separated into five groups: sham-injected, baseline control, vehicle-only-administered, and low-dose
(6.0μg/kg) or high-dose (60.0μg/kg) h-PTH-administered groups. h-PTH or vehicle was injected subcutaneously six times a week
for 4 weeks beginning 9 weeks after STZ administration. Bone mineral density and mineral contents were significantly lower
in the baseline control and vehicle groups than in the control group. The PTH-administered groups showed higher values compared
with both vehicle and baseline control groups. In bone histomorphometry, both bone volume and bone formation in the STZ group
were markedly reduced. The h-PTH-administered rats showed increase in both bone volume and bone formation, which are related
parameters, but administration of h-PTH did not alter the extent of eroded surface. Our results suggest that intermittent
administration of h-PTH is effective in activating bone formation and in preventing further bone loss in osteoporosis developed
by STZ-induced DM. 相似文献
44.
45.
目的 :探讨颅内疾病的心电图改变及对预后的影响。 方法 :将我院 1999年以来的 10 2例颅内疾病患者的心电图资料按病因分为 4组 ,所有患者均于发病 1~ 2d内入院 ,常规描记 12导联心电图 ,住院期间定期复查。结果 :心电图改变主要为复极障碍 (ST段下移 ,T波倒置、低平或双向以及Q T间期延长 ) ,其次为心律失常。 4 0例重型颅脑外伤及蛛网膜下腔出血者中心电图异常 36例 ,正常 4例 ,死亡组心电图异常率及程度均重于存活组。结论 :“脑型心电图改变”主要表现为ST T改变和冲动起源异常的心律失常是暂时的应激反应。发生急性颅内病变时要及时识别 ,积极予以处理 ,以减轻脑损伤所致的心脏损害。 相似文献
46.
Complete cross-sections from the femoral midshaft of 180 individuals of known height and weight, aged 21–97 y, from a modern Australian population were examined using automatic video image analysis to quantify total subperiosteal porosity (TSPP). More specifically, the aim was to investigate whether age changes were similar in both sexes in (1) total subperiosteal area (TSPA), cortical area (CA) and medullary area (MA), (2) intracortical porosity (ICP), and (3) the respective contributions to TSPP made by MA and intracortical void area (ICVA). Our findings indicated that both sexes showed a significantly greater height normalised TSPA in the 70s as compared with the 20s. Males had consistently larger bones with a greater height normalised CA. In both sexes CA showed a tendency to increase till the 7th decade and then to decline, more so in females. MA approximately trebled in females and doubled in males over the age range studied. Although ICP also increased, from 4–6% in young adults to over 9% in the elderly, it showed a significant difference between the sexes only in the 3rd decade, being greater in males at this stage. By contrast, TSPP became significantly greater in females (from that recorded in the 3rd decade) by the time they reached the 50s, while in males this did not occur till the 80s. It increased from ∼25% in young adults of both sexes to ∼50% in females and ∼37% in males in their 80s. However, in the elderly there was great variability in both sexes in the appearance of bones from individuals of similar chronological age. Some bones differed little from those in younger subjects, others showed greatly increased ICP, still others displayed reduced cortical widths with low ICP. The femoral midshaft resembles other skeletal sites in that age changes in TSPP are more marked in females than males. 相似文献
47.
目的 探讨建立稳定、制作过程简单、创伤小的大鼠脑室系统出血模型的方法 . 方法 取大鼠自体动脉血立体定向下注入右侧侧脑室建立大鼠腩室系统出血模型,对模型组和对照组大鼠在不同时间点进行神经行为学评分,并观察脑室及室周脑组织病理变化. 结果本方法 模型成功率为88.9%(16/18),注血后6h大鼠出现行为异常,7d后行为异常好转;光镜下观察发现注血后24h模型组大鼠室管膜连续性遭到破坏,细胞间隙增宽,室周脑组织轻度水肿及出现红色坏死神经元. 结论 本研究采用的造模方法 模型稳定,制作创伤小,病理变化接近临床. 相似文献
48.
Modic changes following lumbar disc herniation 总被引:4,自引:3,他引:1
Only a small proportion (20%) of patients with LBP can be diagnosed based on a patho-anatomical entity. Therefore, the identification
of relevant subgroups, preferably on a patoanatomical basis, is strongly needed. Modic changes have been described by several
authors as being closely linked with LBP. The aims of this study were to describe the prevalence of Modic changes, their development
as well as their association to LBP, previous disc contour, and surgery in patients with previous severe sciatica. This is
a longitudinal cohort study where the patients were recruited from an RCT comparing two active conservative treatments, the
181 patients, who at baseline had radicular pain in or below the knee; all underwent a physical examination and MRI. MRI’s,
pain history and physical examination of 166 patients were obtained at follow-up 14 months later. The prevalence of Modic
changes type 1 increased from 9% at baseline to 29% at follow-up. At that time, a strong association between Modic changes
and non-specific LBP was noted. Apparently, Modic changes type 1 was more strongly associated with non-specific lumbar pain
than Modic changes type 2. The development of new Modic changes was closely related to the level of a previous disc herniation.
A lumbar disc herniation is a strong risk factor for developing Modic changes (especially type 1) during the following year.
Furthermore, Modic changes are strongly associated with LBP. 相似文献
49.
P. Schubert T. Ogata S. Ferroni A. McRae Y. Nakamura K. Rudolphi 《Journal of molecular neuroscience : MN》1996,28(1-3):185-190
In view of the increasing evidence that a pathological glial activation plays a significant role in the development of neurodegenerative
diseases, we investigated the underlying molecular signaling as a possible target for a pharmacological therapy. Here, we
are particularly focusing on the endogenous modulation of the Ca2+ and cyclic nucleotide-dependent signaling by the nucleoside adenosine and its reinforcement by the xanthine derivative propentofylline
(PPF). As an experimental model, we used cultured rat microglial cells and astrocytes that are immature, show a high proliferation
rate, and resemble in several aspects pathologically activated glial cells. A prolonged increase of the cellular cAMP level
favored the differentiation of cultured astrocytes and associated properties required for the physiological nerve cell function.
On the other hand, a strengthening of the cyclic nucleotide-dependent signaling inhibited potentially neurotoxic properties
of cultured microglial cells. Similar effects were obtained by treatment with propentofylline, which mimicked modulatory adenosine
effects and increased the intracellular level of cAMP and cGMP. Such a pharmacological glial cell conditioning, obtained by
modifying the strength and the timing of these second messengers, may provide a therapy of neurodegenerative diseases in which
a pathological activation of microglial cells and astrocytes is discussed to play a pathogenic role. 相似文献
50.
Summary A total of 824 chain-saw operators who were employed in felling trees in the forestry industry were exposed to local vibration, which produced peripheral blood-flow disorders and lesions in the joints and hand bones. In the last 10 years, they have undergone 24-day balneoclimatic treatment at the Kolobrzeg Health Resort. It was found that a stay in the spa and certain balneological treatments exert a favorable effect on the peripheral blood-flow disorders produced by the local vibration of chain saws. The symptoms (chills and numbing of the fingers, etc.) disappeared in nearly 40% of these workers. An improvement in the objective indices of the peripheral circulation (thermographic and plethysmographic tests) was observed in about 90% of patients treated with brine baths combined with underwater vibratory massage (rotatory) or brine baths alone. The brine bath and vibratory massage have a direct beneficial influence on the peripheral blood flow of pectoral limbs. 相似文献