赛赓啶对 KBV200细胞多药抗性的逆转作用

研究赛赓啶对KB_V200细胞多药抗性的逆转作用及逆转机制。在KB_V200细胞,采用MTT法,测出赛赓啶对长春新碱、阿霉素和鬼臼乙叉甙耐药的逆转系数分别为5.5,2.0和1.9,而对5-氟尿嘧啶、美法仑的细胞毒性作用无明显影响,表明赛赓啶为多药抗性逆转剂。荧光分光光度法测定表明,赛赓啶可使KB_V200细胞内阿霉素蓄积量增加。流式细胞荧光测定显示赛赓啶可增加罗丹明123的蓄积并减慢其外排。免疫细胞化学及狭缝杂交表明赛赓啶不影响KB_V200细胞的P-糖蛋白染色深度和 mdr1 RNA 表达水平。以上结果提示赛赓啶的多药抗性逆转机制是抑制P-糖蛋白泵的功能。     

华蟾蜍毒素对离体豚鼠输精管的作用

华蟾蜍毒素(华蟾素)使离体豚鼠输精管产生剂量依赖性收缩反应,利血平化豚鼠输精管及冷藏输精管对华蟾素反应减弱。给酚妥拉明、维拉帕米后,输精管对华蟾素反应均受抑制,溴苄胺可使反应潜伏期缩短。结果提示华蟾素收缩输精管反应可能与其促进肾上腺素能神经末稍NA释放有关。     

Occurrence of tetrodotoxin and paralytic shellfish poison in the Taiwanese crab Lophozozymus pictor

Paralytic toxicity was detected by tetrodotoxin (TTX) bioassay in all 15 specimens of the xanthid crab Lophozozymus pictor collected from northern Taiwan in 1993. The average toxicity of crab specimens was 921 ± 231 (mean ± S.E.) mouse units. The toxin of crab was partially purified and then identified. It was found that the crab toxin contained TTX and gonyautoxin. The ratio of TTX to gonyautoxin for crab toxin was about 9:1.     

Reoperative Thyroid Surgery

Reoperative thyroid surgery is an uncommon operation associated with a high complication rate. We retrospectively reviewed the data of 115 patients to study the incidence of complications after reoperative thyroid surgery. There were 107 women and 8 men (13.4:1.0) with an average age of 42.8 years (range 18–80 years). The most frequent indication for reoperation was completion thyroidectomy for a carcinoma identified by permanent sections (50 patients, 43.5%). Reoperative surgery was performed on 13 (11.3%) patients with recurrent thyroid cancer. The remaining 52 patients underwent reoperation for recurrent thyrotoxicosis (12 patients, 10.4%), recurrent nodular goiter (28 patients, 24.3%) or recurrent multinodular goiter (12 patients, 10.4%). Seven patients with recurrent nodular goiter and one patient with recurrent thyrotoxicosis underwent total thyroidectomy for the presence of malignancies that were identified by frozen sections. Overall, the interval between the initial and reoperative procedures ranged from 1 day to 33 years (2335 ± 272 days). The length of hospital stay was 5.8 ± 0.5 days. The length of time needed for reoperative thyroid surgery was 122.0 ± 6.2 minutes. There was no 30-day perioperative mortality. The postoperative complications consisted of transient hypoparathyroidism in six patients (5.2%), permanent hypoparathyroidism in two patients (1.7%), transient RLN palsy in 3 patients (2.6%), and permanent recurrent laryngeal nerve palsy in two patients (1.7%). Reoperative thyroid surgery can be performed safely with little morbidity to the patient.     

Effect of chronic renal failure on high-density lipoprotein kinetics

Plasma lipid and lipoprotein concentration and high density lipoprotein (HDL) kinetics were determined in control subjects and patients with chronic renal failure (CRF). Results demonstrated that plasma triglyceride (TG) concentration was significantly higher (P less than 0.001) in patients with CRF, associated with a significant increase in plasma VLDL-cholesterol (P less than 0.002) and a significant decrease (P less than 0.05) in plasma HDL-cholesterol concentration. The rate of removal of 125I-apoAI/HDL from plasma was slower (P less than 0.001) in the patients with CRF, resulting in an increase in the residence time of 125I-apoAI/HDL (P less than 0.001) and a decrease in the fractional catabolic rate (P less than 0.001). Since plasma apoAI concentration was lower in patients with CRF, total apoAI/HDL synthetic rate was also significantly (P less than 0.05) decreased. These data provide support for the view that low plasma HDL-cholesterol concentrations in patients with CRF are related to decreases in the synthetic rate of apoAI/HDL.     

Traumatic eyelid invagination: case reports

Three rare cases of upper eyelid trauma are presented. In high-speed traffic accidents, the upper eyelids were penetrated by glass, avulsed, and then, together with pieces of glass, pushed over the globe and buried deeply in the retrobulbar area. The invaginated eyelids were pulled out gently, the conjunctiva still attached to the globes. They were repaired primarily. In these patients eyelid function and cosmesis were preserved.     

Effects of indomethacin,triamcinolone, and dexamethasone on recombinant human interleukin-1-induced substance P and prostaglandin E2 levels in rabbit knee joints

Intra-articular (i.a.) injection of recombinant human interleukin-1 alpha (rHuIL-1) in rabbit knees induced both an inflammation, as determined by increases in leukocytes in the joint fluid, and cartilage degradation, as measured by loss of proteoglycan. Substance P (SP) and prostaglandin E₂ (PGE₂) levels in the joint lavage are also elevated. Treatment with 5 mg indomethacin/kg, p.o., b.i.d., 2 mg triamcinolone i.a., and 10 mg dexamethasone/kg, p.o., reduced synovial lavage leukocyte counts, as well as PGE₂ and SP lavage concentrations induced with IL-1 injection. However, none of the treatments inhibited rHuIL-1-induced proteoglycan loss.     

Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability

X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.