法乐四联症患儿心肌细胞和红细胞内外钙的变化

为了解法乐四联症（ＴＯＦ）患儿术前心肌舒张功能障碍的原因，采用钙荧光指示剂（Ｆｕｒａ－２）法和原子吸收分光光度（ＡＡＳ）法测定了１２例ＴＯＦ患儿心肌细胞、红细胞内外钙的变化。结果发现：ＴＯＦ术前心肌细胞游离钙（ＭｙｏＣａｉ）（３４７±８５ｎｍｏｌ／Ｌ）较先天性心脏病（简称先心病）组（１２２±１３ｎｍｏｌ／Ｌ）明显升高；红细胞游离钙（ＥｒｙＣａｉ）和红细胞总钙（ＥｒｙＣａｔ）（１．８９±０．５０Ｆ３３５／Ｆ３８５，２１．２±２．９μｍｏｌ／Ｌ红细胞）较先心病组（１．４７±０．０８Ｆ３３５／Ｆ３８５，１３．１±８．７μｍｏｌ／Ｌ红细胞）和健康组亦明显升高，而全血游离钙（ＢＣａｉ）和红细胞钠泵、钙泵活性明显下降。术后除钙泵活性外，ＢＣａｉ、ＥｒｙＣａｉ、ＥｒｙＣａｔ和红细胞钠泵活性均恢复正常。提示，钙内流增多和膜泵活性下降导致ＴＯＦ患儿心肌细胞和红细胞内存在过多钙积聚，可能是其术前舒张功能障碍的重要原因之一。     

心力衰竭患儿红细胞和心肌细胞内外钙的变化

为探讨心力衰竭（简称心衰）与心肌细胞钙代谢的关系，应用钙荧光指示剂Ｆｕｒａ－２和原子吸收分光光度法测定了１１例先天性心脏病合并心衰患儿心肌细胞和红细胞内外钙的浓度。结果发现，心衰时心肌细胞和红细胞内游离钙（２８１±４７ｎｍｏｌ／Ｌ，１．７６±０．０４Ｆ３３５／Ｆ３８５）较非心衰者（１２２±１３ｎｍｏｌ／Ｌ，１．４７±０．０８Ｆ３３５／Ｆ３８５）明显增多，红细胞总钙亦明显升高，但红细胞膜泵活性则较非心衰者下降；心衰纠正后，外周血红细胞内钙及膜泵活性恢复正常。提示，小儿心衰时心肌细胞内存在过多的钙积聚，且可能是心衰时心肌舒张功能障碍的原因之一。     

休克患儿磷脂酶A_2及细胞因子作用研究

目的探讨血清磷脂酶Ａ２（ＰＬＡ２）及细胞因子在休克发生发展中的作用及意义。方法采用ＥＬＩＳＡ法检测１６例休克患儿及２０例健康儿童血清ＰＬＡ２、肿瘤坏死因子（ＴＮＦ－ａ）及白细胞介素（ＩＬ～６）含量,并作临床脏器功能监测、血乳酸、血糖、动脉血气分析及血小板计数。结果休克患儿血清ＰＬＡ２（０．８９±０．６３ｍｐ／Ｌ）、ＴＮＦ－ａ（０、６３±０．２５ｍｇ／Ｌ）及ＩＬ－６（６．８４±１９７ｍｇ／Ｌ）浓度均较正常对照组（０．１７±０．０２ｍｇ／Ｌ、０．０８±０．０１ｍｇ／Ｌ、２．３２±０．６２ｍｇ／Ｌ）明显升高（Ｐ＜０．００１）;多器官功能衰竭组（ＭＳＯＦ）上述３项指标（ＰＬＡ２１．１７±０．７０ｍｇ／Ｌ、ＴＮＦ－ａ０．９１±０．２７ｍｐ／Ｌ、ＩＬ－６７．７０±１．４０ｍｇ／Ｌ）均显著高于单器官功能衰竭组（ＳＯＦ）（ＰＬＡ２０．４８±０．０７ｍｇ／Ｌ、ＴＮＦ－ａ０．４７±０．０５ｍｇ／Ｌ、ＩＬ－６５．５５±０．７０ｍｇ／Ｌ）,死亡组明显高于治愈组。结论ＰＬＡ２水平与病情轻重有关,可作为早期预测ＭＳＯＦ发生的参数、评估治疗效果及预后。选择性投用ＰＬＡ２抑制剂可能成为治疗休克的有效方法。     

哮喘儿童发病与血液一氧化氮、肿瘤坏死因子变化的研究

检测哮喘患儿血浆亚硝酸根／硝酸根（ＮＯ２－／ＮＯ３－）和血清肿瘤坏死因子α（ＴＮＦα）含量，并分析其相关关系。结果：正常对照组ＴＮＦα、ＮＯ２－／ＮＯ３－含量分别为（１６４．８５±３１．０８）ｎｇ／Ｌ和（２９．５４±１４．４３）μｍｏｌ／Ｌ；哮喘发作组分别为（１９８．７６±４２．０６）ｎｇ／Ｌ和（４６．６７±１９．１）μｍｏｌ／Ｌ，明显高于对照组（Ｐ＜０．０１），呈显著正相关（Ｐ＜０．０１）；哮喘缓解组为（１９２．４１±３９．５）ｎｇ／Ｌ和（３２．４±１４．９３）μｍｏｌ／Ｌ，ＴＮＦα高于对照组（Ｐ＜０．０５），ＮＯ２－／ＮＯ３－低于发作组（Ｐ＜０．０１）。提示ＴＮＦα和一氧化氮（ＮＯ）可能参与哮喘发作期气道炎症的形成，ＴＮＦα在缓解期的慢性炎症持续中具有重要意义     

危重病儿甲状腺激素T3,rT3变化的临床意义

目的探讨危重病患儿甲状腺激素的变化及其临床意义。方法危重症患儿共４５例，包括重症肺炎、病毒性脑炎、格林巴利综合征，颅内出血、病毒性心肌炎、食物中毒等。２０例健康儿童为对照组。用美国ＰＡＣＫＡＲＤ公司生产的γ免疫自动计数器测定危重病儿和健康儿童血中Ｔ３及ｒＴ３含量。结果２０例健康儿童和４５例危重病患儿血中Ｔ３分别为（２．８８±０．５２）ｎｍｏｌ／Ｌ和（１．４０±０．７１）ｎｍｏｌ／Ｌ（ｔ＝１３．９８，Ｐ＜０．０１），ｒＴ３分别（为０．７２±０．０８）ｎｍｏｌ／Ｌ和（１．１９±０．７３）ｎｍｏｌ／Ｌ（ｔ＝４．３６，Ｐ＜０．０１），Ｔ３／ｒＴ３分别为２．７４±０．８５和１．６１±０．７９（ｔ＝６．３８，Ｐ＜０．０１）．４例临终状态病儿Ｔ３和ｒＴ３均值分别为０．８６和１．４８ｎｍｏｌ／Ｌ，Ｔ３／ｒＴ３为０．６３。４５例患儿，治愈３７例，好转４例，死亡４例。结论危重病患儿血中Ｔ３、ｒＴ３及Ｔ３／ｒＴ３均显著低于健康儿童．４例临终状态病儿血中Ｔ３、ｒＴ３及Ｔ３／ｒＴ３更低。提示甲状腺激素降低的程度与病情严重程度呈正相关。     

胎粪吸入综合征及并发持续动脉高压的心功能变化

探讨胎粪吸入综合征（ＭＡＳ）及并发持续肺动脉高压（ＰＰＨＮ）患儿的心功能变化。应用ＳＳＤ６５０－Ａｌｏｋａ超声多谱勒诊断仪检测４０例正常新生儿和ＭＡＳ患儿的心功能。结果表明：ＭＡＳ患儿左心功能的ＥＦ％（５３．６２）较对照组（６２．１４）,Ａ／Ｅ（０．７６）较对照组（１．１５）均低和右心功能ＣＯＬ／ｍｉｎ（０．８５）较对照组１．１０及,Ａ／Ｅ（０．７８）较对照组１．２２均明显降低,Ｐ均〈０．０５或０     

碱性成纤维细胞生长因子对胎鼠宫内窘迫脑损害的疗效观察

目的探讨母鼠应用碱性成纤维细胞生长因子（ｂＦＧＦ）是否对胎鼠宫内窘迫脑损害有保护作用。方法将５３只胎龄为２０天的ＳＤ大鼠胎鼠随机分为五组，即正常对照组（Ｃ组）１１只，窘迫对照组（Ｅ组）１０只，ｂＦＧＦ治疗组Ⅰ（Ｄ１组）１０只，ｂＦＧＦ治疗Ⅱ组（Ｄ２组）１０只，ｂＦＧＦ治疗Ⅲ组（Ｄ３组）１２只。在不同时间内静脉注射ｂＦＧＦ，监测静脉注射ｂＦＧＦ后胎鼠脑细胞内外钙、钠、钾含量的变化。结果在钳夹血管前２０分钟静脉注射ｂＦＧＦ后胎鼠脑细胞胞游离钙离子浓度为４７５±９１ｎｍｏｌ／Ｌ；再灌注同时静脉注射ｂＦＧＦ后游离钙离子浓度为４７４±４９ｎｍｏｌ／Ｌ。表明ｂＦＧＦ干预组均明显高于正常对照组（３１５±８７ｎｍｏｌ／Ｌ）（Ｐ＜００１），但亦均低于窘迫对照组（５５２±９４ｎｍｏｌ／Ｌ）（Ｐ＜００５）；同时这两组的脑组织总钙、总钠及总钾含量亦有不同程度的下降。结论无论是在窘迫前还是在缺血再灌注同时静脉注射ｂＦＧＦ，ｂＦＧＦ均可减轻宫内窘迫胎鼠脑细胞钙超载，减轻脑水肿，保护缺氧脑细胞；提示对产妇或窒息新生儿应用ｂＦＧＦ可能有助于减轻窒息新生儿脑损伤     

支气管肺炎合并心力衰竭的发病机理研究

目的探讨支气管肺炎合并心力衰竭（简称心衰）的发病机理。方法对１５例肺炎合并心力衰竭患儿和１７例肺炎患儿及１７例正常健康小儿应用超声心动图检查测定左室收缩末室壁应力、射血分数（ＥＦ）、缩短分数（ＦＳ）和心率矫正之左室周径平均缩短速度（ｍＶｃｆｃ）；测定血管紧张素Ⅱ（ＡⅡ）和红细胞内游离钙水平。结果左室收缩末室壁应力：支气管肺炎合并心衰组（４９±６ｇ／ｃｍ２）较肺炎组（４２±９ｇ／ｃｍ２）和正常对照组（４１±８ｇ／ｃｍ２）增加；ＡⅡ：支气管肺炎合并心衰组（３６６±１６０ｎｇ／Ｌ）较肺炎组（５６±１６ｎｇ／Ｌ）和正常组（３８±８ｎｇ／Ｌ）增高；红细胞内游离钙水平：支气管肺炎合并心衰组Ｆ３３５／Ｆ３８５（１．９０±０．２８）和肺炎组Ｆ３３５／Ｆ３８５（１．８６±０．２６）较正常组Ｆ３３５／Ｆ３８５（１．６６±０．２４）增加；ＥＦ、ＦＳ和ｍＶｃｆｃ无改变。结论支气管肺炎合并心衰无心肌收缩力下降，而ＡⅡ增加、心脏后负荷增加。它们在支气管肺炎合并心衰的发病中起到重要作用。     

β-葡萄糖醛酸苷酶在母乳性黄疸发病中的作用

目的探讨β葡萄糖醛酸苷酶（βＧＤ）在母乳性黄疸发病中的作用。方法采用酶学比色法对４７例母乳性黄疸患儿及６０例正常新生儿粪便、血清及其母乳中βＧＤ活性浓度进行测定，并分析母乳性黄疸患儿βＧＤ活性浓度与血胆红素浓度的相关性。结果母乳性黄疸患儿母乳及粪便βＧＤ活性浓度分别为（１３６±０３０）Ｕ／Ｌ及（１０７±０３０）Ｕ／Ｌ，较正常新生儿［（０７５±０３３）Ｕ／Ｌ及（０５０±０２８）Ｕ／Ｌ］明显增高，二者之间差异有非常显著意义。患儿母乳及粪便βＧＤ活性浓度与血胆红素浓度呈明显正相关。黄疸消退期母乳及粪便βＧＤ活性浓度［（１１１±０３２）Ｕ／Ｌ及（０７２±０２６）Ｕ／Ｌ］较高峰期［（１３６±０３０）Ｕ／Ｌ及（１０７±０１０）Ｕ／Ｌ］明显降低，二者之间差异有非常显著意义。结论母乳及粪便βＧＤ活性浓度增高不仅与母乳性黄疸的发生有关，而且与其严重程度及病程经过密切相关。     

法洛四联症患儿心肌细胞内钙运转与心功能关系的研究

目的探讨法洛四联症(TOF)患儿心肌细胞钙运转与心功能的关系.方法钙荧光指示剂Fura-2法测定心肌细胞游离钙浓度,HP-1000型超声心动图机测定心功能.结果28例TOF患儿红细胞游离钙和总钙浓度较健康组明显高,而钙泵活性明显低下;其中8例舒张功能正常者红细胞钙泵活性与健康组无差别,而20例舒张功能异常者不仅钙泵和钠泵活性较舒张功能正常者明显下降,且红细胞游离钙和总钙浓度亦较舒张功能正常者升高.结论TOF患儿心肌细胞内钙运转与其心肌舒张功能异常密切相关.     

Disorders of calcium metabolism

Calcium is crucial for normal neuromuscular activity. It also has a structural role as a component of bone where most of it is present. Plasma calcium is dependent on two main hormones, 1,25-dihydroxyvitamin D and parathyroid hormone, and their interactions with gut absorption, renal excretion and bone mineralization. Disorders of calcium metabolism may result in both hypo- and hypercalcaemia. In children, the former is more common than the latter.Vitamin D undergoes two hydroxylation steps before becoming active. Deficiency or a defect in its metabolism results in rickets, hypocalcaemia or both. Parathyroid hormone is secreted by the parathyroid glands in response to hypocalcaemia under the influence of calcium-sensing receptors. Deficiency of, or failure to respond to, this hormone results in hypocalcaemia, and excess secretion causes hypercalcaemia. Abnormalities of calcium-sensing receptors cause both hypo- and hypercalcaemia.Treatment is directed towards maintaining normal calcium concentrations whilst preventing hypercalciuria.     

Intracellular calcium handling in cystic fibrosis: normal cytosolic calcium and intracellular calcium stores in neutrophils

We used quin2, a high affinity fluorescent calcium indicator to measure free cytosolic Ca++ in neutrophils isolated from fresh heparinized blood of 13 cystic fibrosis (CF) patients (age range 6-32 yr) and 11 healthy individuals (age range 25-41 yr) as controls. The mean value of free cytosolic Ca++ for CF patients was 137 +/- 19 nM (mean +/- SD) and 141 +/- 23 nM for controls (p = NS). Calcium stores released after exposure of the cells to ionomycin in Ca++-free medium were also similar in neutrophils of CF patients (51 +/- 34 pmol/10(6) neutrophils) and in the controls (50 +/- 15 pmol/10(6) neutrophils). Stimulation of the neutrophils with the chemotactic peptide f-mlp (10(-7) M) led to similar rises in free cytosolic Ca++ with mean peak levels of 718 +/- 230 nM in CF patients and 687 +/- 321 nM in another population of 10 healthy adults. In our group of CF patients free cytosolic Ca++, intracellular Ca++ stores, and the kinetics of intracellular Ca++ transients induced by f-mlp are similar to those of normals. These findings do not support the hypothesis of a generalized defect in calcium handling at the cellular level in CF.     

Bone mineral acquisition in low calcium intake children following the withdrawal of calcium supplement

Our recent 18-month calcium supplementation trial demonstrated a significant increase in radial bone mineral mass in 7-year-old children with calcium intake ∼ 300 mg/day (Am J Clin Nutr 1994; 60: 744-50). The persistence of higher bone mass after cessation of calcium supplementation is unknown. This is a follow-up study to investigate the lasting effect of calcium supplementation on bone acquisition. Subjects were 159 Chinese children aged 8.7 years. Distal one-third radial bone mineral content (BMC) and bone width (BW) were measured by single-photon absorptiometry. After 12 months, the significant difference in mean ± SD percentage radial BMC disappeared between the study and control groups (7.34 ± 6.77% vs 8.67 ± 6.46%. p > 0.05). Dietary calcium intakes were similar between the groups. During the supplementation phase, the study group had 17.9% greater BMC gain than that of controls. In the follow-up phase, however, the study group had 16.1% less BMC gain than that of controls. It appears that an increased acquisition rate during the supplementation phase was almost balanced by a reduced acquisition rate during follow-up phase. Moreover, throughout the entire 30-month period, the overall BMC acquisition rates of the study and control groups were 25% and 23.8%, respectively. Hence, the overall acquisition rate of the study group was only 5% higher than that of controls. Therefore, the effect of calcium supplementation on bone mineral gain appears to reflect a transient reduction in bone turnover rate. Longer-term calcium trials are necessary to confirm whether a sustainable higher calcium intake throughout childhood will enhance peak bone mass.