Further delineation of the KBG syndrome caused by ANKRD11 aberrations

Loss-of-function variants in ANKRD11 were identified as the cause of KBG syndrome, an autosomal dominant syndrome with specific dental, neurobehavioural, craniofacial and skeletal anomalies. We present the largest cohort of KBG syndrome cases confirmed by ANKRD11 variants reported so far, consisting of 20 patients from 13 families. Sixteen patients were molecularly diagnosed by Sanger sequencing of ANKRD11, one familial case and three sporadic patients were diagnosed through whole-exome sequencing and one patient was identified through genomewide array analysis. All patients were evaluated by a clinical geneticist. Detailed orofacial phenotyping, including orthodontic evaluation, intra-oral photographs and orthopantomograms, was performed in 10 patients and revealed besides the hallmark feature of macrodontia of central upper incisors, several additional dental anomalies as oligodontia, talon cusps and macrodontia of other teeth. Three-dimensional (3D) stereophotogrammetry was performed in 14 patients and 3D analysis of patients compared with controls showed consistent facial dysmorphisms comprising a bulbous nasal tip, upturned nose with a broad base and a round or triangular face. Many patients exhibited neurobehavioural problems, such as autism spectrum disorder or hyperactivity. One-third of patients presented with (conductive) hearing loss. Congenital heart defects, velopharyngeal insufficiency and hip anomalies were less frequent. On the basis of our observations, we recommend cardiac assessment in children and regular hearing tests in all individuals with a molecular diagnosis of KBG syndrome. As ANKRD11 is a relatively common gene in which sequence variants have been identified in individuals with neurodevelopmental disorders, it seems an important contributor to the aetiology of both sporadic and familial cases.     

HIV/AIDS infection control enforcement: a comparison between Nigeria and the United States

We examined differences in approaches to HIV-related infection control practices in two university teaching hospitals in the United States and Nigeria. Health care workers (n = 202 in Nigeria and 186 in the USA) responded to a previously validated measure of infection control practices. There were significant differences in the estimated probability of treating a person with HIV disease (higher in USA), and a greater probability of peer ridicule as a way of enforcing group norms on infection control in Nigeria. Peer enforcement of norms was significantly lower in the USA. In both countries, more precautions would be taken if it was known that the patient was HIV infected. Infection control practices were more likely to be followed in the USA compared with Nigeria if they were praised for this activity, if appropriate facilities (sharps containers, gloves, etc.) were nearby, and if they felt that infection control procedures were effective. These data point to the importance of normative social pressures in Nigeria and of knowing the patient is HIV infected in the USA and feeling that infection control procedures are effective ways of avoiding occupational HIV infection. The role of normative pressures and assumptions about HIV infection status as well as cues and availability of facilities for infection control appear to differ between these health care workers in Nigeria and the USA.     

商陆多糖Ⅰ联合白细胞介素2对小鼠脾细胞杀瘤活性的影响

商陆多糖Ⅰ(PAP-I),0.3～3μg·ml^-1和小鼠脾细胞培养3～5d可显著增强其杀伤P815肿瘤细胞活性及IL-2(250～500IU·ml^-1)诱导的LAK细胞活性,最适浓度为1μg·ml^-1。PAP-I及IL-2和脾细胞培养的上清液对P815肿瘤细胞无细胞毒作用,但能增强脾细胞及LAK细胞杀瘤活性。PAP-I,5,10及50mg·kg-1,ip可增强脾细胞杀伤P₈₁₅和L₉₂₉细胞的活性及IL-2诱导的LAK细胞活性。     

Inhibition of growth and induction of apoptosis in human cancer cell lines by tea polyphenols

In order to study the biological activities of tea preparations and purified tea polyphenols, their growth inhibitory effects were investigated using four human cancer cell lines. Growth inhibition was measured by [3H]thymidine incorporation after 48 h of treatment. The green tea catechins (-)-epigallocatechin-3-gallate (EGCG) and (-)- epigallocatechin (EGC) displayed strong growth inhibitory effects against lung tumor cell lines H661 and H1299, with estimated IC50 values of 22 microM, but were less effective against lung cancer cell line H441 and colon cancer cell line HT-29 with IC50 values 2- to 3- fold higher. (-)-Epicatechin-3-gallate, had lower activities, and (-)- epicatechin was even less effective. Preparations of green tea polyphenols and theaflavins had higher activities than extracts of green tea and decaffeinated green tea. The results suggest that the growth inhibitory activity of tea extracts is caused by the activities of different tea polyphenols. Exposure of H661 cells to 30 microM EGCG, EGC or theaflavins for 24 h led to the induction of apoptosis as determined by an annexin V apoptosis assay, showing apoptosis indices of 23, 26 and 8%, respectively; with 100 microM of these compounds, the apoptosis indices were 82, 76 and 78%, respectively. Incubation of H661 cells with EGCG also induced a dose-dependent formation of H2O2. Addition of H2O2 to H661 cells caused apoptosis in a manner similar to that caused by EGCG. The EGCG-induced apoptosis in H661 cells was completely inhibited by exogenously added catalase (50 units/ml). These results suggest that tea polyphenol-induced production of H2O2 may mediate apoptosis and that this may contribute to the growth inhibitory activities of tea polyphenols in vitro.      

Luciferase expression and bioluminescence does not affect tumor cell growth in vitro or in vivo

Live animal imaging is becoming an increasingly common technique for accurate and quantitative assessment of tumor burden over time. Bioluminescence imaging systems rely on a bioluminescent signal from tumor cells, typically generated from expression of the firefly luciferase gene. However, previous reports have suggested that either a high level of luciferase or the resultant light reaction produced upon addition of D-luciferin substrate can have a negative influence on tumor cell growth. To address this issue, we designed an expression vector that allows simultaneous fluorescence and luminescence imaging. Using fluorescence activated cell sorting (FACS), we generated clonal cell populations from a human breast cancer (MCF-7) and a mouse melanoma (B16-F10) cell line that stably expressed different levels of luciferase. We then compared the growth capabilities of these clones in vitro by MTT proliferation assay and in vivo by bioluminescence imaging of tumor growth in live mice. Surprisingly, we found that neither the amount of luciferase nor biophotonic activity was sufficient to inhibit tumor cell growth, in vitro or in vivo. These results suggest that luciferase toxicity is not a necessary consideration when designing bioluminescence experiments, and therefore our approach can be used to rapidly generate high levels of luciferase expression for sensitive imaging experiments.     

Magnetic resonance angiography findings in the early post-carotid endarterectomy period

This preliminary study was designed to investigate the ability of multiple axial volume three-dimensional fourier transform (3DFT) time-of-flight (TOF) magnetic resonance angiography (MRA) to depict the carotid bifurcation in the early post-carotid endarterectomy period. Five patients underwent intra-operative digital subtraction angiography (DSA) and carotid MRA within 5 days of carotid endarterectomy. An axial volume fast imaging in steady-state precession (FISP) gradient-echo 3DFT TOF carotid MRA technique in this limited series appeared to display accurately the surgically significant abnormalities at the carotid bifurcation after endarterectomy. However, in normal or near-normal intra-operative DSA studies, overestimation of internal carotid artery stenoses was encountered. Postoperative MRA demonstrates potential as a useful non-invasive investigation after carotid endarterectomy but should be interpreted with caution until larger studies become available.     

Induction of apoptosis by the ginsenoside Rh2 by internalization of lipid rafts and caveolae and inactivation of Akt

Background and purpose:

Lipid rafts and caveolae are membrane microdomains with important roles in cell survival signalling involving the Akt pathway. Cholesterol is important for the structure and function of these microdomains. The ginsenoside Rh2 exhibits anti-tumour activity. Because Rh2 is structurally similar to cholesterol, we investigated the possibility that Rh2 exerted its anti-tumour effect by modulating rafts and caveolae.

Experimental approach:

A431 cells (human epidermoid carcinoma cell line) were treated with Rh2 and the effects on cell apoptosis, raft localization and Akt activation measured. We also examined the effects of over-expression of Akt and active-Akt on Rh2-induced cell death.

Key results:

Rh2 induced apoptosis concentration- and time-dependently. Rh2 reduced the levels of rafts and caveolae in the plasma membrane and increased their internalization. Furthermore, Akt activity was decreased and consequently, Akt-dependent phosphorylation of Bad, a pro-survival protein, was decreased whereas the pro-apoptotic proteins, Bim and Bax, were increased upon Rh2 treatment. Unlike microdomain internalization induce by cholesterol depletion, Rh2-mediated internalization of rafts and caveolae was not reversed by cholesterol addition. Also, cholesterol addition did not restore Akt activation or rescue cells from Rh2-induced cell death. Rh2-induced cell death was attenuated in MDA-MB-231 cells over-expressing either wild-type or dominant-active Akt.

Conclusions and implications:

Rh2 induced internalization of rafts and caveolae, leading to Akt inactivation, and ultimately apoptosis. Because elevated levels of membrane rafts and caveolae, and Akt activation have been correlated with cancer development, internalization of these microdomains by Rh2 could potentially be used as an anti-cancer therapy.     

An audit of metal stent palliation for malignant biliary obstruction

BACKGROUND AND AIMS: Endoscopic stent insertion is the optimum method of palliation for malignant biliary obstruction. Metal stents have several advantages over the polyethylene alternatives, but are significantly more expensive. It has been reported that patients need to survive beyond 6 months to make metal stents more cost-effective. The aim of this study was to audit the performance of expanding metal biliary stents in our endoscopy unit, and to identify factors that might help with patient selection. METHODS: The records of all patients who were selected for endoscopic metal stent insertion at the Royal Perth Hospital for malignant biliary obstruction between September 1994 and November 1998 were reviewed. RESULTS: Thirty-two patients (16 males, mean age 71 years (range 34-88 years) were identified and followed up for a mean 201 days (range 3-810 days). Fifteen (47%) had cholangiocarcinoma, 13 (41%) had pancreatic cancer, and four had metastatic disease as the cause of obstruction. Mortality rates after metal stent insertion were 16, 41 and 55% at 30, 90 and 180 days, respectively. In total, 24 (75%) patients died during the follow-up period. Eleven (34%) stents became obstructed during follow up with a median time to occlusion of 125 days (range 44-729 days). Patients with cholangiocarcinoma had significantly longer survival than pancreatic cancer cases (median 286 vs 58 days, P = 0.04). No other factors were found to correlate with the survival or stent complications. CONCLUSIONS: Less than half of this mixed cohort survived beyond 6 months. Metal stent palliation of malignant biliary obstruction should probably be targeted at those with cholangiocarcinoma, as these patients tend to survive longer.