Association of serum lipoprotein(a) with ultrasonographically determined early atherosclerotic changes in the carotid and femoral arteries in kidney transplanted patients

OBJECTIVES: To evaluate the association of serum lipoprotein(a) [Lp(a)] with carotid intimal media thickness (IMT) and carotid femoral plaque occurrence in kidney transplant patients. PATIENTS AND METHODS: Fifty-four subjects included 29 group 1 normal healthy persons and 25 group 2 kidney transplant patients underwent carotid IMT measurements and carotid femoral plaque assessment by B-mode ultrasonography. Also we measured cholesterol, triglyceride, HDL-C, LDL-C and Lp(a) as well as BUN and creatinine. RESULTS: There was a significant difference between Lp(a) in the two groups (P = .016). There was a significant difference between carotid IMT of the two groups (P < .001). Moreover there was a significant difference between the plaque scores of kidney transplant patients and the normal group (P = .05). There were no correlations between carotid IMT and plaque score in normal subjects or in kidney transplant patients (P > .05). There was a significant correlation between carotid IMT with age in Group 1 (P = .035). No correlation between carotid IMT and serum Lp(a) was seen in the two groups. No significant correlations between plaque score and serum Lp(a) were observed. There was no correlation between duration of transplant and thickening of intimal media complex in this group. In this group a positive correlation was demonstrated between carotid IMT with serum LDL-C (P < .001). CONCLUSIONS: Age was the most important factor associated with thickening of intimal media complex in normal subjects and in plaque formation in the renal transplant group. Serum LDL-C may be associated with thickening of intimal media complex in kidney transplant patients. Serum Lp(a) may not be a significant factor in thickening of the intimal media complex or plaque occurrence in kidney transplant patients.     

低密度脂蛋白和高密度脂蛋白相对全蛋黄溶液在猕猴精子低温冷冻中的作用

最近,住各种动物精子低温冷冻的实验中,提取于鸡蛋蛋黄中的低密度脂蛋白被视为优于全蛋黄溶液。与此同时,有研究认为蛋黄中的高密度脂蛋白可能对解冻后精子的生存产生负面影响。关于低密度脂蛋白和高密度脂蛋白在猕猴精子低温冷冻作用的研究还未有过报道。本研究在加和不加渗透型抗冻剂（甘油）两种情况下,通过与全蛋黄溶液对比的手段评价了两种脂蛋白在猕猴精子低温冷冻中的作用。此外,本研究也尝试多种能够改造精于膜与低密度脂蛋白结合体成分的添加剂对保存解冻精子活力的作用。我们的实验结果表明,低密度脂蛋白是伞蛋黄溶液在猕猴精子低温冷冻中发挥保护作用的主要成分。不管有无添加甘油,低密度脂蛋白与令蛋黄溶液在保存解冻精子活性方面作用相近,并未显现出任何优越性。通过加入胆同醇、胆固醇环糊精复合物或卵磷脂来改变精子膜与低密度脂蛋白结合体成分的方法并未改善解冻精子的存活状况;但加入甲基-β-环糊精则明显降低解冻精于的活力。高密度脂蛋白对猕猴精子低温冷冻保存不存在负面影响。对猕猴精子低温冷冻保存而言,本研究表明全蛋黄溶液相比较于稀释液中的有效成分低密度脂蛋白仍然具有优越性。     

Familial occurrence of bilateral intracranial occlusion of the internal carotid arteries (Moya Moya)

In a family of 14 brothers and sisters, 3 cases of occlusive disease of the large intracranial vessels (Moya Moya) were found. Each of the three had one or more cerebrovascular attacks and a typical cerebral angiogram. Eight other members of the family had severe headaches. Angiography was carried out in three of these with normal findings.     

The effects of isolated lipoproteins and triglyceride, combined oxidized low density lipoprotein (LDL) plus triglyceride, and combined oxidized LDL plus high density lipoprotein on the contractile and relaxation response of rabbit cavernous smooth muscle

The aim of this study was to investigate the effects of isolated lipoproteins and triglyceride (TG), and the effects of combined oxidized low density lipoprotein (LDL) plus TG and the combined oxidized LDL plus high density lipoprotein (HDL) on the contractility and relaxation response of rabbit cavernous smooth muscle. Cavernous muscle strips from New Zealand White rabbits were studied in organ chambers for isometric tension measurement. The strips were exposed to HDL, LDL, oxidized LDL, TG, combined oxidized LDL plus TG and combined oxidized LDL plus HDL for 30 min. Both HDL and LDL did not affect contraction and relaxation responses of the cavernous muscles. The oxidized LDL did not affect norepinephrine (NE)-induced contractility of the strips, but significantly ( p < 0.05) decreased the relaxation response to endothelium-dependent agonist, acetylcholine (Ach). Non-specific NO synthase inhibitor (L-NAME) completely inhibited the relaxation response to Ach, and L-arginine partially improved the diminished relaxation. TG did not significantly change the relaxation responses to Ach, but decreased the contractility of cavernous muscle to NE. Neither the combined oxidized LDL plus TG nor oxidized LDL plus HDL had significant synergistic or detoxication effects on the contractility and relaxation responses. In conclusion, oxidized LDL may have acute toxic effects on the endothelium-dependent, NO-mediated relaxation, but not on the contractility, of rabbit cavernous smooth muscle. TG may decrease contractility of the cavernous muscle. There may be neither synergistic nor detoxication effects on the contractility and relaxation response when TG or HDL is added to the oxidized LDL.     

Prediction of relapse by plasma lipoprotein(a) concentration in children with steroid-sensitive nephrotic syndrome

AIM: To clarify whether plasma lipoproteins, including Lp(a), can predict relapse pattern in the first years after diagnosis of nephrotic syndrome (NS), we evaluated them in patients with steroid-sensitive NS. METHODS: We analyzed the medical records of 35 patients with steroid-sensitive NS who were seen by us from January 1992 to December 1999 followed for at least 1 year. These patients were divided into two groups. Group 1 consisted of 20 patients who infrequently relapse (IR: <2 in 6 months or <3 in a year), group 2 consisted of 15 patients who frequently relapse (FR: > or =2 in 6 months or > or =3 in a year). Clinical and laboratory findings such as age at onset, gender, urinalysis, serum level of total protein, albumin, and concentrations of serum lipid including lipoprotein(a) (Lp(a)) were investigated between group 1 and group 2. RESULTS: The concentration of plasma Lp(a) in group 2 was higher than that in group 1 (81.0 +/- 35.2 vs. 35.9 +/- 26.5 mg/dl, p < 0.01). On multivariate analysis using logistic regression model, the concentration of plasma Lp(a) was an independent risk factor for relapse of NS. CONCLUSIONS: Our findings suggest that of all the laboratory data examined, high values of Lp(a) can predict future relapse of NS and should be well documented.     

Clinical studies on Suncefal (cefpiramide) concentration in prostatic tissue and bladder wall

The cefpiramide (CPM) concentration in prostatic tissue of 19 patients with benign prostatic hypertrophy and bladder wall of 2 patients with bladder tumors was measured, after 2 g of CPM was administered intravenously by bolus technique prior to operation. Prostatic tissue level was 28.4 to 131 micrograms/g and tissue to serum ratio 0.15 to 0.63 at 12 min. to 220 min. after administration. The T1/2 of CPM in prostatic tissue was 3.29 hours. The bladder wall level was high at both determinations. CPM level in prostatic tissue and bladder wall covered the minimum inhibitory concentration of many bacteria detected from the infected sites. Therefore, CPM which has a strong antimicrobial activity can be considered as a highly useful antibiotic for the treatment of postoperative infections.     

Regular use of margarine-containing stanol/sterol esters reduces total and low-density lipoprotein (LDL) cholesterol and allows reduction of statin therapy after cardiac transplantation: preliminary observations.

Seventeen stable cardiac transplant recipients, of whom 16 were on statin therapy, used margarine with stanol/sterol esters. Total cholesterol in the treatment group was lowered from 211 mg/dl (range 168 to 244) to 177 mg/dl (136 to 241) (17% reduction, p = 0.003) and low-density lipoprotein (LDL) cholesterol was reduced from 125 mg/dl (73 to 161) to 98 mg/dl (57 to 146) (22% reduction, p = 0.0006). LDL cholesterol reached the pre-defined cut-off level of 115 mg/dl in 12 of 17 patients and statin dosages were reduced. In 8 of 12 patients, LDL cholesterol remained at <115 mg/dl 6 weeks after statin reduction.     

Effects of Furegrelate (Upjohn 63557A) on patency and platelet deposition after canine carotid endarterectomy

Platelet deposition upon endarterectomy sites is a likely cause for early postoperative thrombosis, embolism and restenosis. Platelets aggregate by the thromboxane-prostacycline mechanism. Thromboxane synthetase inhibitors which have been safely administered to humans should reduce platelet deposition after surgical therapy and therefore reduce peri-operative mortality and the prevalence of stroke. A randomized prospective controlled trial was designed to determine vessel patency and platelet deposition associated with the use of 3 mg/kg and 30 mg/kg of Furegrelate (Upjohn U63557A) daily in dogs, who were to have carotid endarterectomy. The 46 treated and 46 control dogs had total carotid patency of 96% and 76% respectively (P less than 0.01). Fourteen dogs treated with 30 mg/kg Furegrelate had no occlusions, compared with a 19% prevalence in 13 controls (P less than 0.02). Furegrelate 10 mg/kg significantly lowered platelet aggregation. Platelet deposition was not significantly changed, however. The reason for this disparity was a probable persistence of vessel wall factors which promoted platelet deposition. This approach might therefore lower rates of peri-operative thrombosis but it would be very unlikely to alter the incidence of restenosis or embolism. Further research could be directed towards modifying the stimuli for platelet deposition upon the endarterectomy site.     

脂蛋白（a）对肾小球系膜细胞的作用

目的探讨脂蛋白（ａ）［Ｌｐ（ａ）］对肾小球系膜细胞（ＧＭＣ）的作用。方法将体外培养的系膜细胞，加脂蛋白（ａ）刺激后，测定细胞生长率和细胞上清中血小板活化因子（ＰＡＦ）、肿瘤坏死因子（ＴＮＦ）、乳酸脱氢酶（ＬＤＨ）及纤维连结蛋白（ＦＮ）水平，并以未经刺激者作对照。结果经脂蛋白（ａ）刺激４８小时，在终浓度５～２０ｍｇ／Ｌ时细胞生长率轻度增加，而在５０～４００ｍｇ／Ｌ时细胞生长率明显下降。刺激１８小时，细胞上清中ＰＡＦ的水平明显高于对照，且与脂蛋白（ａ）浓度呈明显正相关（ｒ＝０．９３７，Ｐ＜０．０１）；Ｌ９２９细胞的杀伤率有所增加，但未达５０％；ＬＤＨ的水平在脂蛋白（ａ）１００ｍｇ／Ｌ以下时有所增加；刺激１８、４８、７２小时后的细胞上清纤维连结蛋白均为阴性。结论脂蛋白（ａ）对系膜细胞体外增殖有低浓度轻度促进、高浓度抑制的双向作用，对细胞ＰＡＦ的产生具有浓度依赖的促进作用，并能增加细胞上清中ＬＤＨ及ＴＮＦ水平，因而可通过多种途径介导肾小球损伤。     

Flow patterns and distributions of fluid velocity and wall shear stress in the human internal carotid and middle cerebral arteries

BackgroundThe aim of this study is to elucidate the relationship between the flow patterns and the preferred sites of the development of atherosclerotic lesions and cerebral aneurysms in the human ICA and MCA.MethodsFive isolated transparent arterial trees containing the ICA and MCA with a sufficient length of the carotid siphon were prepared from humans postmortem, and flow patterns and distributions of fluid velocity and wall shear stress in these vessels were studied in detail using flow visualization and high-speed cinemicrographic techniques.ResultsIn the carotid siphon that contained several acute bends, due to the impingement and deflection of the flow at the bends, a strong and complex helicoidal flow formed. As a result, the approaching velocity profile was flattened at the terminal bifurcation of the ICA, but it was sharpened at the first bifurcation of the MCA. Thus, at this latter bifurcation, fluid elements impinged on the vessel wall around the flow divider with much larger velocity than that at the preceding terminal bifurcation of the ICA. Throughout the entire arterial tree, atherosclerotic lesions were found almost exclusively in regions of low wall shear stress.ConclusionsThe carotid siphon provided a flattened approaching velocity profile at the terminal bifurcation of the ICA, making the hemodynamic stresses (pressure, tension, and shear stress) exerted on the vessel wall much lower than that at the bifurcation of the MCA where the approaching velocity profile was sharpened. This may account for the relatively low incidence of aneurysm formation at this site.     

Uptake of tetracycline by aortic aneurysm wall and its effect on inflammation and proteolysis.

BACKGROUND: Proteolytic degradation of the aortic wall by matrix metalloproteinases (MMPs) is considered important in the pathogenesis of abdominal aortic aneurysms (AAAs). Many of these MMPs are inhibited by tetracycline derivatives, which may have the potential to retard aneurysm growth. METHODS: Patients undergoing elective repair of an AAA (n = 5) received an intravenous bolus of tetracycline (500 mg) on induction of anaesthesia and levels of tetracycline in serum, aneurysm wall and mural thrombus were assessed by microbiological assay. In a separate series of patients (n = 7) aneurysm biopsies were placed into explant culture (with and without tetracyline) and the accumulation of protein, hydroxyproline, MMP-9, interleukin (IL) 6 and monocyte chemoattractant protein (MCP) 1 in the medium was assessed by colorimetric assay or immunoassay. RESULTS: At aortic cross-clamping the median concentration of tetracycline was 8.3 microg/ml in serum, 2.9 microg per g tissue in aortic wall and zero in mural thrombus. Tetracycline inhibited, in a concentration-dependent manner, both MMP-9 and MCP-1 secretion (P = 0.022 and P = 0.018 respectively), but did not alter hydroxyproline or IL-6 secretion. At the highest concentration of tetracycline (100 microg/ml) median MMP-9 secretion was reduced from 27 to 5 ng/ml (P = 0.007) and median MCP-1 secretion was reduced from 50 to 10 ng/ml (P = 0.008). CONCLUSION: Tetracycline rapidly penetrates the aortic wall, but the concentration achieved may be insufficient to alter collagen turnover through limitation of MMP production or activity.     

One hundred percent patency of one-millimeter polytetrafluoroethylene (Gore-tex) grafts in the carotid arteries of rats

Expanded polytetrafluoroethylene arterial interposition grafts with an internal diameter of 1.0 mm were placed in the carotid arteries of rats. At 2 weeks, 100% patency rate was achieved by the use of strict sterile technique in 23 rats. In contrast, only 1 out of 21 grafts remained open in rats operated using standard clean but nonsterile technique, 5% patency. All thrombosed grafts showed evidence of infection. Orally administered aspirin at therapeutic doses prolonged bleeding times in the rats but did not affect patency results in either group.     

Familial aortic aneurysms: serum concentrations of triglyceride, cholesterol, HDL-cholesterol and (VLDL + LDL)-cholesterol

Patients with abdominal aortic aneurysms (AAAs) have been compared with healthy controls with respect to the serum concentrations of triglyceride, cholesterol, HDL-cholesterol and (VLDL + LDL)-cholesterol. The concentrations of triglyceride and (VLDL + LDL)-cholesterol in serum were higher in the patients than in the controls, while the concentration of HDL-cholesterol in serum was lower in the patients than in the controls. There was no statistically significant difference in the serum concentration of total cholesterol between the patients and the controls. Twelve patients had first degree relatives (brothers, sisters and/or parents) with AAAs and six patients had second degree relatives (cousins or brothers and sisters of the parents) with AAAs. There was no statistically significant difference between the patients who had first degree relatives with AAAs and the patients without AAAs in the family in the serum concentrations of triglyceride, cholesterol, HDL-cholesterol and (VLDL + LDL)-cholesterol.     

The effect of triiodothyronine (T3) and reverse triiodothyronine (rT3) on canine hemorrhagic shock

The euthyroid sick ("low T3") syndrome occurs in circulatory collapse and could influence survival. To evaluate the role of T3 and rT3 in shock, 36 mongrel dogs were subjected to hemorrhagic shock. In 13 dogs 15 micrograms/kg of T3 was given after 60 min of hypotension and 15 micrograms/kg of rT3 was administered IV 30 min before hemorrhage in 10 dogs. An equal volume of saline was injected in 13 dogs for control study. These dogs were bled rapidly into a reservoir to a mean arterial pressure (MAP) of 40 mmHg. After 60 min of hypotension the reservoir line was clamped for 30 min. The shed blood was then reinfused over 30 min. T3 administration caused significant increases during the clamped period in cardiac output, stroke volume, MAP, right and left ventricular stroke work and systemic vascular resistance, with a decrease in pulmonary vascular resistance (PVR). In the group receiving rT3 the only significant hemodynamic-metabolic differences were PVR and mean arterial pH. In the control group, 6 of 13 dogs died, whereas 9 of 10 dogs given rT3 died (p less than 0.03) and only one of 13 T3 dogs died (p less than 0.05). This study strongly suggests that T3 improves survival by acting on cardiovascular receptors or via the hypothalamic-pituitary-thyroid axis and that exogeneous rT3 is detrimental during the stress of shock and may play a biologically causative role in the sick euthyroid syndrome.     

Structural changes of the pseudocyst of the pancreas arteries after its emptying by punctural aspiration (experimental investigation)

Punctural aspiration of the contents of the pseudocyst cavity caused reduction of the diameter and internal cavity, but failed to result in its full involution. Structural changes in the pseudocyst wall developed from the following phases of the counteraction (first 24 hours), remodeling (from the 1st through 16th day) and stabilization (from the 16th day through the 31st day). Cellular reactions of its wall were characterized by a reduced number of neutrophil leukocytes, increased number of macrophages from the 1st through the 7th day and increased number of fibroblasts and lymphocytes as compared with the control group.