维持性血液透析患者血清干细胞因子与皮肤瘙痒的关系

背景：目前慢性肾功能衰竭皮肤损害的发病机制尚未完全阐明。干细胞因子在慢性肾脏病及其并发症的发生、发展过程中可能起至关重要的作用。国内外有关维持性血液透析患者外周血干细胞因子水平的变化及其与皮肤瘙痒的关系鲜有报道。 目的：检测尿毒症维持性血液透析患者外周血干细胞因子水平的变化,并分析其与皮肤瘙痒的关系。 方法：采用ELISA法检测86例维持性血液透析患者外周血干细胞因子水平,采用目测类比评分法对尿毒症皮肤瘙痒程度进行评分,根据分值分为4组,0-2分组23例,3-5分组21例,6-8分组24例,>8分组18例。比较各组间干细胞因子水平的差异,并分析其与血红蛋白、全段血甲状旁腺激素的相关性。 结果与结论：各组患者性别、年龄、体质量指数和血压比较差异均无显著性意义(P > 0.05)。随着尿毒症皮肤瘙痒程度的加重,外周血干细胞因子水平逐渐升高(P < 0.05),血红蛋白水平逐渐降低(P < 0.05),全段血甲状旁腺激素逐渐升高(P< 0.05)。外周血干细胞因子水平与血红蛋白呈明显负相关(r =-0.60,P < 0.01);与全段血甲状旁腺激素呈明显正相关(r =0.7,P < 0.01)。提示外周血干细胞因子可能在尿毒症皮肤瘙痒的发生、发展过程中起重要作用。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

Effects of 1-alpha OH D3 therapy in uremic patients in conservative or dialytic treatment.

The effects of phosphate restriction and of 1 alpha OH D3 administration were investigated in patients with advanced chronic renal failure. Few modifications of the various biochemical parameters in the patients were achieved with the restriction of dietary phosphate while better results were obtained with 1 alpha OH D3 administration. In dialyzed patients the treatment with this drug resulted in a normalization in serum calcium and alkaline phosphatase levels and in a remarkable significant decline in plasma parathyroid hormone and a reduction in the bone disease associated with uremia. This treatment in dialyzed uremic patients could avoid the employment of higher dialysate calcium concentration potentially dangerous for postdialysis hypercalcemia with the risk of metastatic calcifications.     

血液透析联合血液灌流治疗尿毒症的效果

目的 探究血液透析联合血液灌流对尿毒症的治疗效果。方法 选取本院2018年1月~2019年1月收治的84例尿毒症患者作为研究对象,采用随机数字表法分为研究组与常规组,各42例。常规组采用血液透析治疗,研究组在此基础上联合血液灌流治疗。比较两组生活优良率、皮肤瘙痒程度、血清血红蛋白、甲状旁腺激素、尿素氮（BUN）及肌酐（Cr）水平。结果 研究组生活优良率为66.67%,优于常规组的38.10%,差异有统计学意义（P＜0.05）;研究组皮肤瘙痒评分低于常规组,差异有统计学意义（P＜0.05）;两组生化指标均较治疗前改善,差异有统计学意义（P＜0.05）;研究组血红蛋白、甲状旁腺激素优于常规组,差异有统计学意义（P＜0.05）;两组BUN、Cr比较,差异无统计学意义（P＞0.05）。结论 血液透析联合血液灌流能够提高尿毒症的治疗效果,改善患者皮肤瘙痒程度,提高患者生活质量,促进其各项生化指标恢复正常。     

Peripheral nerve function in acute and chronic uremia in rats

There is good evidence that uremic neuropathy is due to a dialysable toxin which causes a generalised and reversible slowing of the nerve conduction velocity (for review see Nielsen 1979). However, the toxin has not been identified and its mode of action is unknown. The present report describes the peripheral nerve function in acute and chronic experimental uremia.     

Effects of 1,25 (OH)2D3 treatment on lipid levels in uremic hemodialysis patients.

The aim of this study was to evaluate the effect of 1,25 (OH)2D3 treatment on lipid levels in uremic hemodialysis (HD) patients. Thirty-one HD patients who had never been treated with vitamin D nor related drugs and 12 healthy subjects with normal renal functions were studied. Uremic HD patients were randomly divided into two groups. Sixteen uremic HD patients were treated with oral calcitriol (0.5 micrograms/day) for 8 weeks. 13 uremic HD patients and 12 healthy subjects were given placebo. In all these cases before and after 8 weeks of treatments; serum total lipid, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride levels were determined. After calcitriol treatment, triglyceride levels were significantly decreased. But total lipid, cholesterol, HDL-cholesterol and LDL-cholesterol levels did not significantly change. In the other two groups there were no significant changes. These results show that calcitriol treatment has a positive effect on triglyceride levels in uremic HD patients. This effect of mechanism of calcitriol treatment has not been known yet. But it could be due to regulation carbohydrates metabolism and normalization of parathormone (PTH) levels.     

Effect of recombinant human erythropoietin (r-HuEPO) therapy on plasma FT3, FT4, TSH, FSH, LH, free testosterone and prolactin levels in hemodialysis patients.

The aim of this study was to evaluate the effect of r-HuEPO treatment on free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), free testosterone and prolactin levels in uremic hemodialysis patients. Twenty-four uremic hemodialysis patients were given r-HuEPO with a dose 60 U/kg as intravenous bolus injection at the end of each dialysis session. Once the hematocrit value of the patient had reached a range of 30-35%, the dose was adjusted so as to keep the hematocrit levels constant. Twenty uremic dialysis patients were taken as control group. The above-mentioned hormone levels of patients and control group were determined before and 4 months after r-HuEPO treatment. After the treatment, serum prolactin levels significantly decreased in both sexes (36.8 +/- 7.8 vs 22.9 +/- 6.3 ng/ml and 78.3 +/- 13.3 vs 37.4 +/- 10.4 ng/ml male and female, respectively). FT3 and FT4 significantly increased (1.17 vs 1.67 pg/ml, p < 0.05, and 0.64 vs 0.084 ng/dl, p < 0.05, respectively). TSH levels increased but those changes were not significant. There was no change in the level of any hormone in the control group. Also, the sexual functions of eight male patients treated with r-HuEPO improved and menstruation started again in four female patients. We concluded that r-HuEPO treatment especially decreases prolactin level in uremic hemodialysis patients. It is conceivable that correction of elevated prolactin levels could improve sexual disorders in these patients.     

Selective deficiency of 1,25-dihydroxycholecalciferol. A cause of isolated skeletal resistance to parathyroid hormone.

To investigate the role of vitamin D metabolites in the pathogenesis of pseudohypoparathyroidism, we studied an elderly man with a unique variant of the disease, which was characterized by hypocalcemia, elevated serum parathyroid hormone (513 +/- 13 pg per milliliter, mean +/- S.E.M., normal, less than 450) but normal renal responses (phosphate and cyclic AMP) to exogenous parathyroid extract. Treatment with parathyroid extract did not produce a calcemic effect, suggesting an isolated skeletal hyporesponsiveness to parathyroid hormone. Although 25-hydroxyvitamin D levels were not reduced, levels of 1,25-dihydroxycholecalciferol were extremely low (0.52 ng per deciliter; normal 3.3 +/- 0.06, S.D.). Treatment with 1,25-dihydroxycholecalciferol (1 microgram by mouth per day for four days) increased circulating levels to normal (4.60 ng per deciliter) and restored to normal the calcemic response to parathyroid (change in calcium 3.0 mg per deciliter). These data suggest that 1,25-dihydroxycholecalciferol deficiency may explain the skeletal resistance, but not the renal resistance, often present in classic pseudohypoparathyroidism.     

Quotidian nocturnal hemodialysis improves cytokine profile and enhances erythropoietin responsiveness

Inflammation is implicated in the pathogenesis of erythropoietin (EPO) resistance in patients with end-stage renal disease. Interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha are suggested to suppress erythropoiesis in uremia. Insulin like growth factor (IGF)-1 has been proposed to stimulate erythropoiesis. Nocturnal hemodialysis (NHD) has been demonstrated to improve anemia management with enhanced EPO responsiveness without altering survival of red blood cells. We tested the hypothesis that augmentation of uremia clearance by NHD results in a reduction of proinflammatory cytokine levels, thereby enhancing EPO responsiveness. Using a cross-sectional study design, 14 prevalent patients on NHD and 14 patients on conventional hemodialysis (CHD) matched for age and comorbidities and controlled for hemoglobin concentrations and iron status were studied. Outcome variables included EPO requirement and plasma levels of EPO, parathyroid hormone, C reactive protein, IL-6, TNF-alpha, and IGF-1. The primary outcome was to determine the between group differences in (1) cytokine profile and (2) EPO requirement. The secondary outcome was to examine the potential correlation between cytokine levels and EPO requirement. There were no significant differences in patient characteristics, comorbidities, hemoglobin, iron indices, and parathyroid hormone levels between the two cohorts. EPO requirement was significantly lower in the NHD cohort [90.5 +/- 22.1 U/kg/ week (NHD) vs. 167.2 +/- 25.4 U/kg/week (CHD), p = 0.04]. Plasma IL-6 levels were lower in the NHD cohort [3.9 +/- 0.7 pg/ml (NHD) vs. 6.5 +/- 0.8 pg/ml (CHD), p = 0.04]. C reactive protein tended to decrease [4.59 +/- 1.34 (NHD) vs. 8.43 +/- 1.83 mg/L (CHD), p = 0.14]. TNF-alpha, and IGF-1 levels did not differ between the two groups. Direct associations were found between EPO requirement and C reactive protein levels (R = 0.62, p = 0.001), and IL-6 levels (R = 0.57, p = 0.002). Augmentation of uremic clearance by NHD improves EPO responsiveness in end-stage renal disease. A possible mechanism for this improvement is through better control of inflammation, as manifested by lowering of plasma IL-6 levels. Further studies are required to clarify the mechanisms by which NHD decreases inflammation.     

Relief of pruritus and decreases in plasma histamine concentrations during erythropoietin therapy in patients with uremia.

BACKGROUND. The pathophysiologic aspects of pruritus in patients with chronic renal insufficiency are poorly understood, and there is no universally effective treatment. The improvement of pruritus in several patients receiving erythropoietin therapy raised the possibility that erythropoietin affects uremic pruritus directly. METHODS. We undertook a 10-week placebo-controlled, double-blind, crossover study in a group of patients receiving hemodialysis who had severe pruritus, to investigate the effects of recombinant human erythropoietin on their pruritus and plasma histamine levels. Twenty patients with uremia, of whom 10 had severe pruritus and 10 did not, received erythropoietin (36 units per kilogram of body weight three times weekly) and placebo in random order, each for five weeks. The severity of pruritus was scored weekly, and plasma histamine levels were measured at the beginning and end of each five-week period. RESULTS. Eight of the 10 patients with pruritus had marked reductions in their pruritus scores during erythropoietin therapy. The mean (+/- SE) pruritus score decreased from 25 +/- 3 to 6 +/- 1 in these patients. The pruritus returned within one week after the discontinuation of therapy. The improvement was not related to the change in hemoglobin level. These eight patients were successfully treated again with low doses of erythropoietin (18 units per kilogram three times weekly), and the effect has persisted for six months. The patients with pruritus had elevated plasma histamine concentrations (20.7 +/- 2.7 nmol per liter), as compared with the patients without pruritus (4.2 +/- 0.6 nmol per liter; P less than 0.001) and normal subjects (2.1 +/- 0.2 nmol per liter; P less than 0.001). Therapy with erythropoietin induced a decrease in plasma histamine concentrations in both groups of patients with uremia, and recurrences of pruritus after the discontinuation of erythropoietin were accompanied by increases in plasma histamine concentrations. CONCLUSIONS. Erythropoietin therapy lowers plasma histamine concentrations in patients with uremia and can result in marked improvement of pruritus.     

Intravenous calcitriol in the treatment of refractory osteitis fibrosa of chronic renal failure

Osteitis fibrosa, a frequent complication of chronic renal failure, is characterized by increased rates of bone formation and bone resorption due to increased secretion of parathyroid hormone (PTH). Effective treatment with oral calcitriol is often impossible in patients with osteitis fibrosa, because low doses may cause hypercalcemia. Because short-term infusions of intravenous calcitriol are capable of suppressing the secretion of parathyroid hormone in patients with uremia without causing hypercalcemia, we evaluated the effectiveness of long-term intermittent calcitriol infusions (1.0 to 2.5 micrograms three times weekly, during dialysis) in treating severe osteitis fibrosa in 12 consecutive patients on hemodialysis whose disease was refractory to conventional therapy. After a mean (+/- SE) treatment period of 11.5 +/- 1.4 months, the mean bone-formation rate declined from 1642 +/- 277 to 676 +/- 106 microns 2 per square millimeter per day (P less than 0.01) in the 11 patients who successfully completed the study. Similar reductions occurred in the osteoblastic osteoid (18 +/- 3 to 9 +/- 2 percent; P less than 0.01) and the degree of marrow fibrosis (6.2 +/- 1.7 to 3.5 +/- 1.3 percent; P = 0.01). Concomitant serum biochemical changes included increased calcium levels (2.55 +/- 0.03 to 2.67 +/- 0.05 mmol per liter; P less than 0.01), decreased alkaline phosphatase levels (489 +/- 77 to 184 +/- 32 U per liter; P less than 0.001), and decreased levels of PTH (amino-terminal, 172 +/- 34 to 69 +/- 16 ng per liter in five patients, P less than 0.03; and carboxy-terminal, 1468 +/- 467 to 1083 +/- 402 ml-eq per liter in six patients, P not significant). Although the majority of the patients had transient episodes of asymptomatic hypercalcemia, this complication could be quickly reversed by temporarily halting treatment or decreasing the dose of calcitriol. We conclude that long-term intermittent infusions of intravenous calcitriol are effective in ameliorating osteitis fibrosa in patients on dialysis. Patients whose osteitis fibrosa is refractory to oral calcitriol and who are candidates for parathyroidectomy should be considered first for intravenous calcitriol therapy.     

强化神经营养方案辅助胰岛素对糖尿病周围神经病变患者治疗及预后的影响

目的:分析强化神经营养方案辅助胰岛素对糖尿病周围神经病变患者治疗及预后的影响.方法:将2015年1月至2016年8月期间收治的糖尿病周围神经病变患者105例按随机分配原则,将所有患者分入到观察组(53例)和对照组(52例).对照组采用常规胰岛素治疗,观察组采用强化神经营养联合胰岛素方案.观察两组治疗的效果.结果:观察组治疗总体有效率高达90.57%,而对照组为75.47%,两者差异具有统计学意义(P<0.05).治疗前,两组患者神经传导速度及氧化应激指标差异均无统计学意义(P>0.05).治疗后,两组患者的各指标得到明显改善,且观察组患者的感觉、运动神经传导速度及氧化应激指标的改善效果显著优于对照组,差异具有统计学意义(P<0.05).结论:强化神经营养方案辅助胰岛素治疗糖尿病周围神经病变的患者,可以显著提高神经传导速度,降低机体内氧化应激反应,提高治疗效果.     

Effect of vitamin D intake on seasonal variations in parathyroid hormone secretion in postmenopausal women

Vitamin D intake should be sufficient to maintain calcium absorption and prevent increased parathyroid secretion throughout the year. To determine the level of intake that achieved the latter in elderly women, we studied the interrelations among vitamin D intake, serum 25-hydroxyvitamin D (25(OH)D) levels, and parathyroid hormone concentrations in a cross-sectional study of 333 healthy, white, postmenopausal women with low median calcium (408 mg a day) and vitamin D (112 IU a day) intakes who lived in Massachusetts. The overall inverse relation between serum parathyroid hormone and 25(OH)D levels was found to be dependent on vitamin D intake. In women whose estimated intake of vitamin D was less than or equal to 220 IU a day, the mean (+/- SD) serum parathyroid hormone values were lowest in those studied between August and October (30 +/- 11 ng per liter; n = 72) and highest in those studied between March and May (37 +/- 16 ng per liter; n = 54); the respective serum 25(OH)D levels were 93 +/- 32 and 63 +/- 21 nmol per liter. At vitamin D intakes of more than 220 IU a day, the mean serum parathyroid hormone and 25(OH)D levels did not vary with the season. The correlation between vitamin D intake and serum 25(OH)D concentration, although significant in all women (r = 0.29; P less than 0.001), was highest in those studied between March and May (r = 0.65; P less than 0.001) and lowest in those studied between August and October (r = 0.13; P greater than 0.10). The estimated serum 25(OH)D level associated with a vitamin D intake of 220 IU a day between March and May was 95 nmol per liter. Mean serum calcium values were similar at all times in both groups. We conclude that the dietary intake of more than 220 IU of vitamin D a day by postmenopausal women in Massachusetts may be sufficient to maintain constant serum 25(OH)D and parathyroid hormone concentrations throughout the year. Such an intake prevents a seasonal increase in parathyroid hormone secretion, with its possible deleterious skeletal effects.     

EGFR and p53 expression and proliferative activity in parathyroid adenomas; an immunohistochemical study

EGFR (epidermal growth factor receptor), p53, and proliferative markers provide some clues as to the formation of several tumours. In this study the mechanism of the genesis of parathyroid adenomas was investigated using immunohistochemistry. Sections of parathyroid adenomas from 12 cases were stained using PCNA (proliferating cell nuclear antigen), EGFR, and p53 immunohistochemistry. Correlations between PCNA LI (labelling index), EGFR expression, p53 expression, age, serum parathormone, Ca and P levels, and tumour diameter were investigated. PCNA LI was 45.8+/-33.1 (mean+/-standard deviation) and all the cases were somewhat positive. Five cases (41.67 %) were EGFR positive. Maximum 10 % of the cells were positive in these cases. All the cases were p53 negative. There was a correlation between PCNA LI and serum parathormone level (r=0.607, p=0.036). According to these results, parathormone synthesis is high when the proliferative activity of parathyroid adenoma is high. Four of the five EGFR-positive patients were below 35 years of age. These data may indicate that formation of parathyroid adenoma in young patients is related to a mechanism involving EGFR. Absence of p53 expression suggests that p53 mutation is not a common component of parathyroid adenomas.     

Surgical treatment of mediastinal parathyroid adenoma

Ectopic parathyroid adenoma is a frequent cause of persistent or recurrent hyperparathyroidism after parathyroidectomy in patients with chronic renal failure on dialysis. An unusual anatomic localization of parathyroid adenoma may make the diagnosis and surgery difficult. In a 41-year-old woman with chronic renal failure, increased serum level of parathyroid hormone and symptoms of progressive renal osteodystrophy, mediastinal parathyroid adenoma was detected in the aorticopulmonary window by 99m Tc sesta MIBI scintigraphy and transmission computed tomography. Extirpation of adenoma, sized 3 x 2 cm, was performed through a left thoracotomy. Serum parathormone level returned to normal and the patient steadily recovered.     

Abnormalities in parathyroid hormone secretion and 1,25-dihydroxyvitamin D3 formation in women with osteoporosis

We investigated the parathyroid hormone-1,25-dihydroxyvitamin D3 (1,25(OH)2D) axis in osteoporosis by administering phosphate to 8 postmenopausal women with osteoporosis (49 to 78 years old) and to 10 normal women matched for age (50 to 74 years). All subjects responded with a similar increase in the serum phosphorus concentration (women with osteoporosis, 1.15 +/- 0.06 to 1.79 +/- 0.09 mmol per liter; controls, 1.14 +/- 0.05 to 1.73 +/- 0.08 mmol per liter) and a fall in the ionized calcium concentration (women with osteoporosis, 1.12 +/- 0.03 to 1.06 +/- 0.03 mmol per liter; controls, 1.17 +/- 0.01 to 1.11 +/- 0.02 mmol per liter). Parathyroid hormone levels rose 2.5-fold in the control group (15.4 +/- 2.2 to 37.9 +/- 6.1 pg per milliliter) but increased by only 43 percent in the group with osteoporosis (14.8 +/- 2.8 to 21.2 +/- 4.1 pg per milliliter), an increase similar to that previously reported in young normal subjects (53 percent). In healthy older and younger subjects, the levels of 1,25(OH)2D did not change; in the subjects with osteoporosis, however, they decreased significantly (50 percent). We conclude that older women require a greater parathyroid hormone stimulus than younger women to maintain vitamin D homeostasis, because of an age-related decline in the formation of 1,25(OH)2D in response to parathyroid hormone, and that in osteoporosis the age-appropriate parathyroid hormone response to the same hypocalcemic signal is diminished. Our results are consistent with the presence of an abnormality in parathyroid hormone secretory function in osteoporosis in addition to the universal decline in 1,25(OH)2D responsiveness associated with aging.     

西那卡塞对维持性血液透析继发性甲状旁腺功能亢进患者FGF-23的影响

目的 研究西那卡塞对维持性血液透析继发性甲状旁腺功能亢进患者FGF-23的影响。方法 选取2015年1月~2016年10月在天津市第一中心医院血液净化中心行维持性血液透析治疗合并继发性甲状旁腺功能亢进的患者,按入院顺序随机分为观察组及对照组,对照组40例,给予骨化三醇治疗,观察组39例,给予对照组患者相同的骨化三醇治疗的基础上,再加用盐酸西那卡塞片,两组均连续治疗3个月。监测两组治疗前后的尿素氮、血肌酐、KT/V、血清钙、血清磷、碱性磷酸酶、钙磷乘积、全段甲状旁腺激素 (iPTH)及血清FGF-23。结果 治疗后,两组患者的BUN、SCr和Kt/V 较治疗前,差异无统计学意义（P＞0.05）;血清钙观察组治疗后低于对照组（P＜0.05）,对照组治疗前后,差异无统计学意义（P＞0.05）;两组血清磷、ALP、钙磷乘积、iPTH、FGF-23治疗后降低,且治疗后观察组优于对照组,差异有统计学意义 (P<0.05)。结论 西那卡塞对于维持性血液透析合并继发性甲状旁腺功能亢进的患者能够降低甲状旁腺激素及FGF-23水平,缩小甲状旁腺体积。     

Control of uremic neuropathy by equilibrium peritoneal dialysis

Motor nerve conduction velocity (MNCV), sensory nerve conduction velocity (SNVC) and distal motor latencies times (DMLT) were evaluated both in upper and lower limbs in three groups of 15 patients of comparable age, treated respectively by extracorporeal dialysis (HD), continuous ambulatory peritoneal dialysis (CAPD) and combined peritoneal dialysis (CPD) for comparable sufficiently long periods. Moreover, MNCV was monitored longitudinally in two groups of patients shifted from CAPD to HD and vice versa. The results show a significant superiority of peritoneal dialysis and particularly of CAPD with respect to HD in controlling uremic neuropathy.     

Early deposition of aluminum in bone in diabetic patients on hemodialysis

Aluminum-associated bone disease is a special problem in uremic patients on hemodialysis. We have observed this disorder in uremic patients with insulin-dependent diabetes soon after the start of dialysis treatments. We therefore studied bone biopsy specimens from 18 diabetic patients on hemodialysis to determine whether aluminum accumulates on bone surfaces at an accelerated rate in diabetes. We also measured the rates of bone formation, because lower rates may enhance the accumulation of aluminum on bone surfaces. As compared with 18 nondiabetic controls with uremia who were matched for age and duration of dialysis, the patients with diabetes had a higher rate of aluminum accumulation on bone surfaces (2.1 +/- 0.7 vs. 0.4 +/- 0.2 percent per month, P less than 0.01) and a lower rate of bone formation (117 +/- 50 vs. 396 +/- 81 microns 2 per square millimeter per day, P less than 0.01). Also, the patients with diabetes whose cumulative aluminum intake exceeded 0.5 kg had higher serum aluminum levels after an infusion of deferoxamine, as compared with controls matched for aluminum intake (P less than 0.01). These measurements reflected a higher aluminum content in the whole body in patients with diabetes. We suggest that the enhanced rate of aluminum accumulation on bone surfaces in uremic patients with diabetes occurs as a result of a low rate of bone formation and an increased accumulation of aluminum in the whole body.     

Decreased expression of calcium receptor in parathyroid tissue in patients with hyperparathyroidism secondary to chronic renal failure

The response of parathyroid cells to serum calcium is regulated by a calcium-sensing receptor protein (CaR). In patients with chronic renal failure, hypocalcemia contributes to the parathyroid hyperplasia and increased parathyroid hormone secretion characteristic of secondary hyperparathyroidism (sHPT). However, patients with uremia also display reduced sensitivity to extracellular calcium; this seems to be owing to an alteration of the receptor mechanism. This study examined calcium receptor expression in the parathyroid tissue of patients with sHPT, using immunohistochemical technicques and comparison with normal tissue and parathyroid glands of patients with primary hyperparathyroidism. In all the glands studied, immunostaining was more intense in chief cells than in oxyphilic, transitional, and clear cells. The parathyroid glands of patients with sHPT displayed significantly reduced expression of CaR with respect to morphologically normal ones; a very similar reduction is reported in adenomas. Furthermore, in glands displaying multinodular hyperplasia, expression was less marked in nodule-forming cells than in internodular areas. The decreased expression of calcium receptors in the parathyroid tissue of uremic patients was thought to be owing to the different cell populations present; these parathyroid glands contained predominantly transitional, oxyphilic, and clear cells, which normally express fewer receptors than chief cells, which are more abundant in normal glands.     

Influence of blood lead concentration on the nerve conduction velocity in patients with end-stage renal disease

Diseases of the peripheral nervous system are the most prevalent in patients with end-stage renal disease (ESRD). Although increased blood levels of lead in ESRD have been reported, the role of lead remains to be elucidated. The purpose of this study was to determine the connection of blood lead concentration with peripheral nerve conduction velocity. One hundred ninety-eight healthy subjects (control group) and 68 patients with ESRD undergoing hemodialysis (ESRD group) were enrolled. Nerve conduction was measured within two hours after hemodialysis. Orthodromic sensory nerve action potentials and compound muscle action potentials were recorded on the median, ulnar, and radial nerves. Hemoglobin-corrected blood lead was significantly higher in ESRD patients than in controls (9.1+/-2.8 microgram/dL vs. 5.9+/-2.3 microgram/dL, p<0.001). 32.4% of 68 ESRD patients with diabetes mellitus were significantly related to poorer motor and sensory nerve conduction velocity (p<0.001). However, blood lead was not a significant predictor of the nerve conduction velocity (p>0.05). Our result suggested that even though the blood lead levels were high in ESRD, they were not associated with the decline of peripheral nerve function. Diabetes mellitus is a primary independent risk of neuropathy in ESRD patients.