Preliminary study on HA coating percutaneously implanted in bone

A comparative investigation on the possibility of hydroxyapatite (HA) coating and pure Ti column to form biological sealing with skin tissue was completed in this study. HA coating and pure Ti column were percutaneously implanted in the tibia of rabbits. Compared with titanium (Ti) implant, HA coating forms epithelial sealing with skin tissue at 6 weeks postoperatively, while the Ti implant may loosen from the implanted site and be lost. The Ti column loosing rate at this time was 50%. However, once the Ti implant becomes fixed with the bone tissue, it can form epithelial sealing with skin tissue just like the HA coating, at 8 weeks postoperatively. At 8 weeks postoperatively, the epithelial sealing is not destroyed in spite of the fact that the HA coating is biodegraded. Our results show that the HA coating can become fixed with the bone faster than the Ti, which is beneficial for epithelial sealing formation. The main role of HA coating for epithelial sealing is beneficial for sealing at the initial period after it is implanted.     

A single-incision technique to harvest subepithelial connective tissue grafts from the palate

This article describes a new and simplified surgical approach to harvest subepithelial connective tissue grafts from the palate. For this procedure, only a single incision parallel to the gingival margin is used to access the donor site for graft preparation and harvesting. Grafts of variable size and thickness can be obtained. Since no band of epithelium is removed with the connective tissue graft the palatal donor site can heal with primary intention. No stents or hemostatic agents are necessary to cover the donor area postoperatively, and suturing can be reduced to a minimum. The harvesting technique is illustrated step by step, and the clinical application of connective tissue grafts harvested with the proposed method is demonstrated with the coverage of a gingival recession.     

Cytoprotective effects of hematopoietic growth factors on primary human acute myeloid leukemias are not mediated through changes in BCL-2, bax, or p21WAF1/CIP1

BACKGROUND: Hematopoietic growth factors (HGF) can suppress chemotherapy-induced programmed cell death (apoptosis) in hematopoietic cells. Although HGF can modulate the expression of apoptosis-regulatory genes, including bcl-2, bax, and p21WAF1/CIP1 in cell lines, few data address whether HGF regulate the expression of these proteins in primary acute myeloid leukemia (AML). MATERIALS AND METHODS: We evaluated the expression of bcl-2, bax, and p21WAF1/CIP1 in primary samples from patients with AML in the presence and absence of HGF. The potential association of HGF-induced changes in the levels of these proteins with inhibition of chemotherapy-induced apoptosis was further investigated. RESULTS: While a combination of steel factor (SF) and PIXY321 inhibited etoposide-induced apoptosis in 8/11 primary AML samples studied, Bcl-2 and bax protein levels were unaffected by exposure to HGF and/or etoposide. In contrast, HGF enhanced basal and etoposide-induced p21WAF1/CIP1 protein levels in 9/11 and 7/11 of the cases, respectively. In several cases, inhibition of apoptosis by HGF was seen without up-regulation of p21WAF1/CIP1 levels, suggesting that modulation of p21WAF1/CIP1 is not required for HGF-mediated inhibition of apoptosis. CONCLUSIONS: These data indicate that HGF-mediated inhibition of chemotherapy-induced apoptosis in primary AML samples is not mediated through changes in Bcl-2, bax, and p21WAF1/CIP1 protein levels.     

Initial results of laser angioplasty under angioscopic guidance for salvage of an ischemic lower limb: preliminary report

From March to July 1989, nine patients at risk for peripheral artery disease underwent intraoperative Nd:YAG laser angioplasty using angioscopy at the Veterans General Hospital (Taipei, Taiwan, Republic of China). Following the laser angioplasty, balloon dilatation was performed in all cases. Eight men and one woman at an average age of 68 were included in the study (range: 58 to 78 years old). Ischemic symptoms included five patients with disabling claudication, four with pain at rest and one with gangrene on the toes. Eight of the nine patients had complete occlusions ranging from 2 to 19 cm in length. Two patients had high degree multiple segmental stenosis of the superficial femoral artery from 1 to 2 cm in length. Initial clinical success (indicated by relief of symptoms and increase in Doppler ankle pressure and index) and improvement in the angiographic luminal diameter was noted in 9 of 10 occluded vessels (90%) that underwent Nd:YAG laser treatment which was delivered at 10 to 12 watts through laser probes. Prelaser intraluminal diameter increased from 0.05 +/- 0.07 to 0.53 +/- 0.07 mm, Doppler ankle pressure index rose from 0.51 +/- 0.12 to 0.81 +/- 0.12, Doppler ankle pressure increased from 62.44 +/- 16.10 to 104 +/- 21.21 mmHg and the amplitude of pulse volume recorder at ankle level rose from 5.77 +/- 2.80 to 12.11 +/- 2.77 mm as compared with prelaser therapy (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Hemin enhances the in vitro growth of primitive erythroid progenitor cells

Since exogenous hemin has been shown to exert a variety of stimulatory effects on erythroid cells, including the augmentation of hemoglobin synthesis, we determined its effect on early stages of erythroid development by employing clonal cells assays. The addition of hemin at a concentration of 2 X 10(-4) M to cultures of normal murine marrow substantially increased the observed number of primitive BFU-E, which was in contrast to its lack of an effect on more mature erythroid colony-forming cells. This cell-specific enhancement of primitive BFU-E resulted in marrow frequencies equivalent to or exceeding those reported in the presence of "burst-promoting activity." In the presence of hemin, the number of BFU-E was also observed to be linearly related to the number of cells plated at very low plating densities, and the cell titration curve was observed to extrapolate to the origin. The evidence suggests that hemin may be a primary growth regulator of early developmental stages of erythroid progenitor cells.     

瘤内注射重组人p53腺病毒治疗晚期肺癌临床试验观察

目的 观察重组人p53腺病毒注射液(rAd-p53)在晚期肺癌治疗中的疗效和毒副反应。方法 12例IIIb-IV期肺癌及3例肺转移癌,CT定位经皮肺穿刺瘤内注射rAd-p53,1 次/周×4/疗程;通过临床观察、CT及病理对照及短期随访进行评价。结果 治疗后2 月观察肿瘤缩小5例(33.3%),无变化7例(46.7%),增大3例(20%);治疗后病理观察:癌组织坏死,癌细胞稀少(6/11,54.5%);除自限性发热外,无明显毒副反应。结论rAd-p53瘤内注射治疗肺癌,无明显毒副作用,能较好地抑制局部肿瘤的发展,尤其对失去手术机会,不能耐受放化疗的患者,是一种可行的有前景的方法。     

Dietary beta-carotene absorption by blood plasma and leukocytes in domestic cats

Three experiments were conducted to study the uptake of oral beta-carotene by blood plasma and leukocytes in domestic cats. In Experiment 1, mature female Tabby cats (12 mo old) were given once orally 0, 10, 20 or 50 mg of beta-carotene and blood taken at 0, 12, 24, 30, 36, 42, 48 and 72 h after dosing. Concentrations of plasma beta-carotene increased in a dose-dependent manner. Peak concentrations were observed at 12-24 h and declined gradually thereafter. The half-life of plasma beta-carotene was 12-30 h. In Experiment 2, cats were dosed daily for six consecutive days with 0, 1, 2, 5 or 10 mg beta-carotene. Blood was sampled once daily at 12 h after each feeding. Daily dosing of cats with beta-carotene for 6 d resulted in a dose-dependent increase in circulating beta-carotene. Experiment 3 was designed to study the uptake of beta-carotene by blood leukocytes. Cats were fed 0, 5 or 10 mg of beta-carotene daily for 14 d. Blood leukocytes were obtained on d 7 and 14 to determine beta-carotene content in whole lymphocytes and in subcellular fractions. Blood lymphocytes took up large amounts of beta-carotene by d 7 of feeding. Furthermore, beta-carotene accumulated mainly in the mitochondria (40-52%), with lower amounts accumulating in the microsomes (20-35%), cytosol (15-34%), and nuclei (1.5-6%). Therefore, domestic cats readily absorb beta-carotene across the intestinal mucosa and transfer the beta-carotene into peripheral blood leukocytes and their subcellular organelles. beta-Carotene uptake kinetics show that some aspects of beta-carotene absorption and metabolism in cats are similar to those of humans.     

止痛活血化瘀药实验研究

本文研究了止痛活血化瘀药对血液流变性的影响。两类止痛活血化瘀药在改善红细胞聚集性、变形性等血液流变性诸参数的作用是明显不同的。结果表明活血散瘀类药可明显改善四项红细胞流变性参数，即通过降低红细胞表明电荷以增加细胞间的排斥力，防止红细胞聚集，改善变形性，降低纤维蛋白元含量，降低血液粘度，改善血液流变性。另一方面，祛风行气类药则可降低血小板聚集性和粘附性。因此，止痛活血化瘀药的作用机理是不同的     

Assessment of the mutagenicity of dichloroacetic acid in lacI transgenic B6C3F1 mouse liver

Dichloroacetic acid (DCA) is a chlorination byproduct found in finished drinking water. When administered in drinking water this chemical has been shown to produce hepatocellular adenomas and carcinomas in B6C3F1 mice over the animal's lifetime. In this study, we investigated whether mutant frequencies were increased in mouse liver using treatment protocols that yielded significant tumor induction. DCA was administered continuously at either 1.0 or 3.5 g/l in drinking water to male transgenic B6C3F1 mice harboring the bacterial lacI gene. Groups of five or six animals were killed at 4, 10 or 60 weeks and livers removed. At both 4 and 10 weeks of treatment, there was no significant difference in mutant frequency between the treated and control animals at either dose level. At 60 weeks, mice treated with 1.0 g/l DCA showed a 1.3-fold increase in mutant frequency over concurrent controls (P = 0.05). Mice treated with 3.5 g/l DCA for 60 weeks had a 2.3-fold increase in mutant frequency over the concurrent controls (P = 0.002). The mutation spectrum recovered from mice treated with 3.5 g/l DCA for 60 weeks contained G:C-->A:T transitions (32.79%) and G:C-->T:A transversions (21.31%). In contrast, G:C-->A:T transitions comprised 53.19% of the recovered mutants among control animals. Although only 19.15% of mutations among the controls were at T:A sites, 32.79% of the mutations from DCA-treated animals were at T:A sites. This is consistent with the previous observation that the proportion of mutations at T:A sites in codon 61 of the H-ras gene was increased in DCA-induced liver tumors in B6C3F1 mice. The present study demonstrates DCA-associated mutagenicity in the mouse liver under conditions in which DCA produces hepatic tumors.      

国产榧属植物种子油含量及其脂肪酸测定

目的:分析了国产榧属植物种子油含量及其脂肪酸组成。方法:用重量法和GC法分别测定油含量和脂肪酸组成。结果:种子油含量在42.6%～54.39%;脂肪酸组成以亚油酸和油酸为主;不饱和脂肪酸占脂肪酸总量的76.1%～82.0%;饱和脂肪酸以山俞酸和棕榈酸为主。结论:榧属植物种子油属优质植物油,含量较高的山俞酸为特征性成分。对榧属植物种子油资源潜在的开发利用价值进行了评价。