鼠抗人醛脱氢酶1A1单克隆抗体的制备与鉴定

醛脱氢酶1A1（ALDH1A1）是醛脱氢酶家族的成员之一，以同源四聚体的形式存在，定位于细胞质，在肝脏、胰腺、生殖器和皮肤成纤维细胞中高表达。ALDH1A1具有视网膜脱氢酶、醛脱氢酶（NAD）、氧化还原酶活性，参与体内多种醛类代谢，氧化不同的脂肪族醛和芳香族醛变成相对应的羧基酸，并具有电子传递及药物解毒的功能。目前市售的抗ALDH1A1抗体均为多克隆抗体，我们在成人抗肝脏胞质蛋白单克隆抗体（mAbs）库的建立过程中，应用细胞质总蛋白免疫BALB／c小鼠得到多株mAbs，其中1株经鉴定确认为鼠抗人ALDH1A1单克隆抗体，并对其特异性进行了鉴定，为进一步研究ALDH1A1的功能提供了特异性检测工具。[第一段]     

Serum allopregnanolone levels in pregnant women: changes during pregnancy, at delivery, and in hypertensive patients

Allopregnanolone is a neuroactive steroid measurable in peripheral circulation. The aim of the present study was to investigate the presence and the possible changes in serum allopregnanolone and progesterone levels in pregnant women during gestation, at delivery, and in patients with chronic hypertension, with or without superimposed preeclampsia. We also evaluated allopregnanolone in cord blood. Three groups of pregnant women were studied: 1) healthy controls followed longitudinally throughout gestation (n = 14); 2) at vaginal or cesarean delivery (n = 66); and 3) with chronic hypertension (n = 12), with (n = 7) or without (n = 5) superimposed preeclampsia. Allopregnanolone and progesterone levels were measured in maternal and cord serum by RIA. In healthy pregnant women, serum allopregnanolone and progesterone levels progressively increased throughout gestation. Whereas no changes were found at vaginal delivery, serum allopregnanolone and progesterone levels were significantly lower at delivery by emergency cesarean section (P < 0.01). Umbilical cord serum allopregnanolone and progesterone levels in emergency cesarean were significantly lower than those found at vaginal delivery (P < 0.01). Patients with chronic hypertension, with or without superimposed severe preeclampsia, showed serum allopregnanolone levels significantly higher than those of healthy women at the same gestational age (P < 0.01). In conclusion, maternal serum allopregnanolone levels increased during normal gestation were lower in women who underwent emergency cesarean and higher in patients with chronic hypertension, with or without preeclampsia. Because allopregnanolone is active on the central nervous system and in the control of systemic blood pressure, an involvement of this neurosteroid in the adaptive processes induced by pregnancy is suggested.     

Off-pump versus on-pump coronary artery bypass: does number of grafts performed represent a selection bias in comparative studies? Results from a matched cohort comparison.

BACKGROUND: Several retrospective studies comparing off-pump and on-pump coronary surgery and the largest randomized studies published to date showed a lower number of grafts performed in patients submitted to off-pump coronary artery bypass surgery (OPCAB). These findings bring about the question of the general applicability of the results. We eliminated the selection bias correlated with the number of grafts per patient by comparing the short-term outcomes of patients undergoing OPCAB and standard coronary artery bypass grafting (CABG) matched for number of grafts. METHODS: Eighty-seven consecutive patients undergoing OPCAB (group A) were selected from the database of our Institution during a 2-year period. Matching was performed by iterative selection prioritizing, in the following sequence: number of grafts, EuroSCORE, and age. A total of 87 patients operated upon with the on-pump technique represented the control group (group B). RESULTS: There were no significant differences in preoperative characteristics between the two groups. The number of grafts per patient was 2.2 +/- 0.5 in group A and 2.2 +/- 0.5 in group B. Early mortality did not differ between the two groups and it was 2.2% (2 patients) in group A and 3.4% (3 patients) in group B (p = NS). The incidence of myocardial infarction did not differ between the two groups. No patient in either group had stroke or coma. Five (5.7%) patients in group A and 7 (8.0%) patients in group B had atrial fibrillation (p = NS). CONCLUSIONS: We were unable to demonstrate any significant differences in short-term mortality or morbidity outcome between OPCAB and standard CABG patients Our findings suggest that excellent results can be obtained with both surgical approaches.     

Different growth factor activation in the right and left ventricles in experimental volume overload

Mechanical factors play a key role in activation of cardiac growth factor response in hemodynamic overload, and both cooperate in myocardial remodeling. The present study was performed to investigate whether a different growth factor response is activated in the right and left ventricles in aortocaval fistula and its effects on regional myocardial adaptation. Relations between regional growth factor expression (angiotensin II, insulin-like growth factor-I, and endothelin-1), myocyte shape changes, and collagen deposition were investigated at mRNA and peptide levels in adult pigs after the creation of an aortocaval fistula distal to the renal arteries (n=15) and in sham-operated animals (n=15). The role of angiotensin II was investigated by the administration of angiotensin-converting enzyme inhibitor or angiotensin II receptor antagonist. In the left ventricle, pure volume overload was accompanied by persistent increase of insulin-like growth factor-I mRNA expression, peptide concentration (2.2-fold versus sham at 3 months, P<0.05), and significant increase of myocyte length (+29% at 3 months, P<0.05). Conversely, the mixed pressure-volume overload faced by the right ventricle resulted in significant regional overexpression of all growth factors investigated (angiotensin II, insulin-like growth factor-I, and endothelin-1), with corresponding increase of myocyte diameter and length and collagen deposition (+117% at 3 months). Collagen accumulation in the right ventricle as well as the increase in right ventricular end-diastolic pressure at the 3-month observation were inhibited by angiotensin II antagonism. The left and right ventricles respond differently to aortocaval fistula, and local growth factor expression is closely related to the regional myocardial adaptation.     

Hemoglobin H disease in Sardinia: phenotypic and genetic observations

In this study the clinical and hematological characteristics, the transmission pattern and the relative rates of globin chain synthesis were determined in the members of four Sardinian families with 14 patients affected by hemoglobin H disease. The severity of hemoglobin H disease in Sardinian subjects shows a high degree of variability. Clinically it usually appears intermediate between the hemoglobin H disease found in Oriental and Negro populations. The alpha/beta specific activity ratio was 0.42 +/- 0.10 indicating an analogous biochemical defect like that described in the Chinese. On the basis of hematological data and alpha/beta ratio, the genetics of hemoglobin H disease in Sardinians seem to follow a pattern similar to that observed in Orientals: one parent showing alpha-thalassemia-1 trait and the other alpha-thalassemia-2 trait. Parent offspring transmission of hemoglobin H disease did occur in 2 out of 6 hemoglobin H matings with spouses carrying the alpha-thalassemia-1 gene. This observation indicates either a high frequency of alpha-thalassemia trait in Sardinians or a high incidence of inbreeding. In one family the mating of a patient with hemoglobin H disease and a normal person produces 6/6 offspring with alpha-thalassemia-1. The genetic implications of this transmission pattern are discussed.     

Alcohol Withdrawal in Rats Is Associated with a Marked Fall in Extraneuronal Dopamine

Withdrawal of rats from chronic ethanol (2-5 g/kg, every 6 hr for 6 days) resulted in withdrawal symptomatology and dramatic fall in extracellular dopamine (DA) in the ventral striatum as measured by microdialysis. The changes in DA output paralleled the withdrawal symptomatology and both phenomena were reversed by a challenge ethanol dose (5 g/kg orally). The results suggest that the decrease in DA output may be responsible for the aversive symptoms of withdrawal.     

Proteolytic conversion of neurohypophyseal peptides by rat thymocytes: involvement of endopeptidases.

The proteolytic conversion of oxytocin and Arg8-vasopressin by purified rat thymocytes was studied at 37 degrees C and physiological pH 7.4. The formed peptide fragments were isolated by high performance liquid chromatography and characterized by amino acid analysis. When oxytocin was incubated with rat thymocytes, oxytocin 1-8 and oxytocin 1-7 were isolated. In contrast, only Arg8-vasopressin 1-8 was found when Arg8-vasopressin was incubated with thymocytes. The formation of oxytocin 1-8, oxytocin 1-7 and Arg8-vasopressin 1-8 was prevented partially by 10(-3) M phenylmethylsulfonyl fluoride and iodoacetamide, and abolished by 0.5 x 10(-3) M Zn2+ and Hg2+ ions and 10(-3) M o-phenanthroline, but not by 10(-5) M leupeptin, lima bean trypsin inhibitor, trasylol, captopril and phosphoramidon. 0.5 x 10(-3) M EDTA was without effect on the formation of oxytocin 1-8 and Arg8-vasopressin 1-8 but increased by about 30% the formation of oxytocin 1-7. The results suggest that proteases capable of metabolizing oxytocin and Arg8-vasopressin are localized in the thymocyte surface membrane. Since oxytocin and vasopressin are synthetized by thymic epithelial cells and exert several actions on thymocytes, these proteases may play a physiological role in the inactivation of neurohypophyseal peptides at the thymocyte level.