Epidermal growth factor in human and bovine milk

The concentration of epidermal growth factor in human and bovine milk was measured by radioreceptor assay. Both human placental plasma membranes and a human epidermoid carcinoma cell were used as the epidermal growth factor receptor source in the assay. The use of placental plasma membrane in the radioreceptor assay gave erroneous results for bovine milk and overestimated the concentration of epidermal growth factor in human milk. Intact cells appear to provide a more accurate measure of the concentration of epidermal growth factor in milk samples. Using A431 cells, we found very low concentrations of epidermal growth factor in bovine milk (less than 2 ng/ml) compared to human milk (30-40 ng/ml). No epidermal growth factor activity was found in several cows' milk-based infant formulas. These results highlight the caution which must be taken when measuring trace substances such as polypeptide growth factors in complex samples such as milk.     

Linkage of polymorphic congenital cataract to the gamma-crystallin gene locus on human chromosome 2q33-35

Cataract is one of the major causes of blindness in humans. We describe here an autosomal dominant polymorphic congenital cataract (PCC) which is characterised by wide variations in phenotype of non-nuclear lens opacities, even among affected members of the same family. PCC families included a large, unique pedigree (254 members, 103 affected individuals), and genetic linkage was conducted using a variety of polymorphic markers. Evidence for linkage was found for chromosome 2q33- 35 with PCC mapping near D2S72 and TNP1. A tri-nucleotide microsatellite marker for gamma-crystallin B gene (CRYG1) was found to co-segregate with PCC and yielded a maximum lod score of 10.62 at (theta = 0). A multipoint analysis demonstrated that the most probable location of the PCC gene was within an 8 cM genetic interval containing the gamma-crystallin gene cluster. These data provide strong evidence of the existence of an autosomal dominant mutation for PCC in or near the gamma-crystallin gene cluster. This defect is characterised by complete penetrance but variable expression of the cataract phenotype. Our study also suggests that non-nuclear human cataracts might be caused by some abnormality in gamma-crystallin genes.      

Cumulus cells are required for the increased apoptotic potential in oocytes of aged mice

Recent studies with female ICR mice have suggested that oocyte DNA fragmentation is one reason for poor oocyte quality and lower fertility associated with ageing. Since it was not determined if this increased 'apoptotic' potential in aged oocytes is due to changes within the oocyte itself or within the microenvironment of cumulus cells (CC) surrounding the germ cell, we sought to clarify if CC were required to affect the rate of apoptosis in oocytes maintained in vitro. Intact cumulus-oocyte complexes (COC) were retrieved by superovulation of virgin female ICR mice at 7 weeks ('young') or 34-35 weeks ('aged') of age. One-half of the COC in each group were incubated at 37 degrees C in human tubal fluid medium under paraffin oil for 24 h. The other half of the COC in each group were denuded of CC and incubated under the same conditions (denuded oocytes; DO). Following incubation, COC were stripped of adherent CC by gentle pipetting. All DO were then fixed and checked by light microscopy for morphological changes characteristic of apoptosis. In young mice, the presence of CC had no significant effect on oocyte death rate (18 +/- 9% and 14 +/- 6% apoptotic oocytes in COC and DO, respectively; P > 0.05). However, in aged mice the percentage of CC-enclosed oocytes that underwent apoptosis was significantly greater as compared to the death rate in DO (48 +/- 3% versus 19 +/- 8% apoptotic oocytes, respectively; P < 0.05). This increased death potential was due to the presence of CC since the occurrence of apoptosis in DO of aged versus young mice was not significantly different (19 +/- 8% versus 14 +/- 6% apoptotic oocytes, respectively; P > 0.05). These results demonstrate that the age-dependent acceleration of apoptosis in oocytes maintained in vitro requires the CC.      

Intracytoplasmic sperm injection in obstructive and non-obstructive azoospermia

We compared the results of intracytoplasmic sperm injection (ICSI) in: (i) obstructive versus non-obstructive azoospermia, (ii) obstructive azoospermia using epididymal versus testicular spermatozoa and (iii) acquired versus congenital obstructive azoospermia due to congenital absence of the vas deferens (CAVD). A retrospective analysis was done of 241 consecutive ICSI cycles done in 103 patients with non- obstructive azoospermia and 119 patients with obstructive azoospermia. In the obstructive group, 135 ICSI cycles were performed. Epididymal spermatozoa were used in 44 cycles and testicular spermatozoa in 91 cycles. In the non-obstructive group, 106 cycles were performed. The fertilization and pregnancy per cycle rates were 59.5 and 27.3% respectively using epididymal spermatozoa, 54.4 and 31.9% respectively using testicular spermatozoa in obstructive cases, and 39 and 11.3% respectively in non-obstructive cases. The fertilization and pregnancy per cycle rates were 56.6 and 37% respectively in acquired obstructive cases, and 55.2 and 20.4% respectively in CAVD. In conclusion, ICSI using spermatozoa from patients with acquired obstructive azoospermia resulted in significantly higher fertilization and pregnancy rates as compared to CAVD and non-obstructive cases.      

Studies of percutaneous epididymal sperm aspiration (PESA) and intracytoplasmic sperm injection

Four distinct studies were carried out using two data sets ofpercutaneous epididymal sperm aspiration (PESA) and intracytoplasmicsperm injection (ICSI) procedures performed from March 1993to January 1997. In study A, an analysis of 181 ICSI treatmentcycles following PESA revealed a successful epididymal spermretrieval rate of 83%. It confirmed that PESA is an effectivesperm retrieval method and the associated ICSI pregnancy rate(35% per embryo transfer) compared favourably with that of othersperm retrieval methods. In study B, the relevance of a priordiagnostic PESA procedure was ascertained by comparing the spermretrieval rates in two groups of patients having their firstICSI treatment cycle with spermatozoa retrieved through PESA.Group B1 (n=50) had diagnostic PESA prior to the ICSI treatmentcycle PESA procedure, unlike patients in group B2 (n=64) whodid not. The sperm retrieval rate in the treatment cycle procedurewas not different at 90 and 82.8% for groups B1 and B2 respectively.However, the discontinuation of diagnostic PESA is fraught withproblems including liability to medico-legal sanctions. In studyC, analysis of 177 treatment cycles involving PESA and ICSIrevealed a successful sperm retrieval rate by PESA of 82% inthe first cycle, 93% in the second, 96% in the third and 100%in the fourth cycle. The same trend was evident when sperm retrievalwas examined in relation to each of the epididymides. Retrievedspermatozoa were found to be motile in 67-100% of cases andthe frequency of samples containing motile spermatozoa did notdecrease with increase in the number of PESA attempts. Theseresults show that PESA does not jeopardize future epididymalsperm retrieval. In study D, the outcome of treatment with ICSIusing ejaculated spermatozoa (305 cycles) (group D1) was comparedwith that of ICSI using spermatozoa obtained through PESA (54cycles) (group D2). The median age of women in the two groupsof couples was similar (34 years). In group D1, 70% of metaphaseII oocytes were fertilized compared with 61% in group D2 (P<0.01).The cleavage rate and the median numbers of transferred andcryopreserved embryos were similar in both groups. There wasno significant difference between the clinical pregnancy rates(33 and 42% in groups D1 and D2 respectively). Our results showthat the outcome of PESA-ICSI treatment compared favourablywith that of ICSI using ejaculated spermatozoa.     

7.5%氯化钠对重症急性胰腺炎肾素-血管紧张素系统过度激活介导的全身炎症反应综合征的影响

目的探讨7.5%Nacl对重症急性胰腺炎时肾素-血管紧张素系统过度激活对大鼠多器官功能损害的保护机制.方法雄性健康SD大鼠64只随机分成4组:假手术对照组(sham):模型组(SAP);平衡盐组(L.R);7.5%高渗盐水组(H.S).动态定量测定血浆血管紧张素Ⅱ(AngⅡ)、内毒素(LPS)、血清TNF-α的变化,免疫组化检测肝组织NF-κ B p65和肠组织ICAM-1的表达,并在光镜下观察肝、肺及肠组织病理学改变.结果L.R组血浆中AngⅡ、TNF-α、LPS水平虽较SAP组低,但与sham组相比明显升高(P＜0.01).H.S组AngⅡ、TNF-α和LPS水平较L.R组显著降低(P＜0.01),SAP组和L.R组的NF-κB p65在汇管区肝细胞核中呈强表达,同时肠组织中ICAM-1表达显著增加,与H.S组相比差异有显著性(P＜0.01).H.S组肝、肺及肠组织病理损害亦明显减轻.结论高渗钠盐能通过抑制肾小球旁细胞释放肾素显著改变了AngⅡ水平,迅速降低AngⅡ这一炎症反应前的因子,减轻或阻断了SAP复苏后依然存在的内脏缺血所致全身炎症反应综合症,这可能是高渗盐治疗SAP的主要机制.过度应激反应在SAP持续发展和SIRS的发生、发展中起了重要的介导作用.     

Effect of combined treatment with gonadotropin releasing hormone analogue and growth hormone in patients with central precocious puberty who had subnormal growth velocity and impaired height prognosis

Growth hormone-insulin-like growth factor-I status and response to growth hormone therapy (0.6 IU/kg/week sc, six times a week for 12 months) were evaluated in 12 girls (chronological age 9.4 ± 1.6 years) suffering from central precocious puberty with growth velocity less than 4 cm/year and no substantial increase or decrease in predicted adult height during gonadotropin releasing hormone (Gn-RH) analogue treatment (D-Trp⁶-LH-RH, 60 μg/kg im/28 days). At baseline, large variations were observed in nocturnal growth hormone (GH) means (pathological values (< 3.6μg/l) 33.3%), stimulated levodopa GH peaks (pathological values (<10.0 μg/I) 28.6%) and serum insulin-like growth factor-I (IGF-I) levels. Neither GH nor IGF-I levels were correlated with growth velocity. During recombinant GH therapy, growth velocity increased significantly (baseline 3.0 ± 0.9 cm/year; 6 months 6.4 ± 1.9cm/year, p < 0.001 versus baseline; 12 months 6.0 ± 1.3cm/year, p < 0.001 versus baseline). There was a significant increase in height SDS for bone age (baseline –1.6 ±0.5 SDS; 12 months -1.04 ± 0.6SDS; p < 0.002) and in predicted adult height (baseline 152.0 ± 3.6cm; 12 months 155.9 ± 3.4cm; p < 0.002). Our results suggest that combined therapy with Gn-RH analogues and recombinant GH can improve growth velocity and predicted adult height in girls with central precocious puberty and impaired height prognosis during Gn-RH analogue treatment.     

nm23-H1表达预测大肠癌转移的价值研究

 目的　大肠癌预后取决于是否存在肿瘤转移,目前尚无肯定的观测大肠癌细胞恶性潜能的生物学指标。本研究目的在于探讨nm23-H1作为预测大肠癌转移指标的潜在价值。方法　采用免疫组织化学链霉菌亲合物素蛋白—生物素酶标(SP)方法对58例存档大肠癌标本进行nm23-H1蛋白表达检测,用SSPS统计软件包对nm-H1表达与临床病理参数的关系进行分析。结果　正常大肠粘膜和大肠腺瘤nm23呈阳性表达,62.1%大肠癌组织阳性表达。nm23表达与肿瘤分级、淋巴结及肝转移负相关(P值分别为0.0100,0.2087,0.00376)。nm23阳性表达的大肠癌患者预后好(P=0.0002)。结论　nm23-H1是预测大肠癌细胞转移潜能和预后的敏感指标。