Cement Equivalence of Metakaolin for Workability, Cohesiveness, Strength and Sorptivity of Concrete.

A series of concrete mixes with metakaolin (MK) content ranging from 0 to 30% and water/cementitious materials (W/CM) ratio varying from 0.30 to 0.50 were produced for performance testing. The results showed that adding MK up to 20% as ordinary Portland cement (OPC) replacement best improved the 28-day and 70-day cube strengths, whereas adding MK up to 30% as OPC replacement always increased the cohesiveness and decreased the sorptivity, but impaired the workability. Moreover, the cement equivalent factor (CEF), i.e. the equivalent mass of OPC per mass of MK added, for each performance attribute, including workability and cohesiveness, was evaluated. Whilst the actual CEF of MK was generally higher at a higher W/CM ratio and lower at a higher MK content, overall, the average CEFs were found to be 1.98, 2.17, 3.83, 1.93, 2.12, and 4.70 for slump, flow, cohesiveness, 28-day cube strength, 70-day cube strength, and sorptivity coefficient, respectively. These CEF values indicated that the MK is a highly effective cementitious material for improving the cohesiveness, strength, and durability. Moreover, it has been demonstrated that the CEFs for workability and cohesiveness are useful parameters in aiding the mix design of MK concrete.

Does sperm morphology play a significant role in increased sex chromosomal disomy? A comparison between patients with teratozoospermia and OAT by FISH.

Eight semen samples from men with teratozoospermia (T), along with samples from 3 men with normal fertility and 5 samples from men with oligoasthenoteratozoospermia (OAT) were analyzed for X and Y chromosomal anomalies with the use of fluorescently labeled centromeric probes. This study was undertaken to determine whether patients with abnormal sperm morphology (teratozoospermia) have increased or decreased incidence of a sex chromosomal anomaly. The sex chromosome disomy for the T samples was 0.36% and for the OAT group it was 0.61%, compared with baseline value for the normozoospermia group (0.09%).

Makaluvic acids A and B: novel alkaloids from the marine sponge Zyzzya fuliginosus.

Two new substituted pyrrolecarboxylic acids, makaluvic acids A (5) and B (6), were isolated from the sponge Zyzzya fuliginosus, which was collected in Chuuk Atoll, Federated States of Micronesia. The known alkaloids 3,7-dimethylisoguanine (1) and makaluvamines A (2), E (3), and K (4) were also isolated.

Cocultures in human assisted reproduction. Support of embryos in vitro and their specificity.

Assisted reproductive techniques (ART) have contributed tremendously to alleviating infertility in childless couples. However, the "take-home baby" rate for in vitro fertilization (IVF) has been much below the rate for normal fertile couples and for the other tubal procedures such as gamete intrafallopian transfer (GIFT) and tubal embryo transfer (TET). It was therefore speculated that the tubal environment might be playing an important role towards the viability of the embryo and that, in IVF, 4-6 cell stage embryos that were usually replaced directly into the uterus might not be receiving the beneficial effects of the tubal environment. Pronuclear stage human and mouse embryos were thus cocultured with reproductive and other somatic cell types to evaluate the quality of the various cleaving stages and the percentage yield of blastocysts. Human ampullary cell cultures were established in 6 to 7 days and kept alive through one menstrual cycle. Cleavage to the compacted and cavitating stages was achieved in 78% and 69%, respectively, of human embryos cocultured in 24-48 hour human ampullary subcultures as compared to 50% and 33%, respectively, for embryos grown in culture medium alone. The percentages of expanded blastocysts and hatching stages in such cocultures were not significantly different from those of controls. However, human ampullary and cumulus and mouse ampullary and muscle fibroblast cultures supported cleavage and development of mouse embryos up to the hatching stages as well as or better than controls. It thus appears that there is no absolute specificity for a reproductive tract source of cocultured cells and that the beneficial effects of ampullary and cumulus cells are not species-specific. The coculture system also appears to overcome the embryonic blocks of the human and mouse, which may be mediated via growth factors that activate the embryonic genome.

Establishment of human ampullary cell cultures.

Epithelial cells from the ampulla of healthy oviducts from 16 women aged 33-41 years and at different phases of their menstrual cycles were used to establish primary cultures and the continuation of a cell line. The morphology and behaviour of these cells in vitro were evaluated using Nomarski's inverted optics, scanning and transmission electron microscopy. Cells from all patients produced confluent monolayers in 6-7 days with no significant relationship of cell growth with stage of cycle. Fourteen primary cultures were of the epithelioid type while two showed mixed epithelioid and fibroblast-like growth. Two distinct cell types (ciliated and secretory) were observed in primary culture. Secretory cells showed several microvilli of different lengths and distribution. Secretory cells predominated over ciliated cells in all patients, but maximum ciliation occurred around the time of ovulation. Structural features of the cells in vitro were remarkably similar to those described in vivo. Ampullary cells could be maintained in vitro through four to six passages with 3-4 days of growth between passages. Sub-cultured cells were all secretory and were of two types (I and II) based on ultrastructure. Secretory vesicles containing electron-dense material and lipids were observed in these cells. The method described allows for the use of ampullary cells as feeder layers for IVF and support of cleaving human embryos and the evaluation of the biochemical events surrounding fertilization and ectopic pregnancies.

Rapid karyotyping of spontaneous abortions with trophoblastic villi.

24-hour short term culture of trophoblastic villi provided rapid and accurate karyotypes in spontaneous first trimester abortions. Good quality metaphases were obtained in 60.0% of villous cultures if these were set up within 8 hours of uterine evacuation, in contrast to the 10.3% success rate with intervals longer than 8 hours. 21% (4 of 19) of first trimester pregnancy losses were chromosomally abnormal, 3 of which were examples of autosomal trisomy; in 2 cases, the mothers were more than 37 years of age. The results of successful karyotyping reported here compare well with previous reports of long term culture of minced fetal material. Further, the risks of infected cultures, maternal contamination and pseudomosaicism are minimal with the short-term culture technique described here. Chorionic villi isolated from spontaneously aborted material are a simple and practicable source of fetal material for rapid and accurate cytogenic diagnosis in early spontaneous abortions.

Bile immunoglobulin of the duck (Anas platyrhynchos). II. Antibody response in influenza A virus infections.

The capacity of the IgM-like bile immunoglobulin (IgX) of the duck (Anas platyrhynchos) to express antibody activity to H3N2 influenza A viruses, and the dependence of this activity on the co-existence of serum IgM antibodies were investigated. Ducklings infected orally and intranasally at 15-29 days of age with viruses isolated from different host species were examined for haemagglutination-inhibiting (HI) antibodies in biles and sera 16-29 days after infection (p.i.). All biles had antibodies associated with IgX; all sera had antibodies associated only with the 7.8S IgG. Following oral infection of birds 42-days-old with influenza A/duck/HK/7/75 virus, serum HI antibodies were an initial IgM response occurring from 5-12 days p.i., followed by the appearance of 7.8S IgG antibodies. Virus-neutralizing (VN) antibodies in serum were also biphasic; isotype classification was not attempted. Bile IgX developed HI and VN activity. HI antibodies reached peak titres 12 days p.i. and fell to low levels by 24 days p.i. VN antibodies also reached peak titres 12 days p.i., but thereafter persisted at quite high levels throughout the experiment. Development of high titres of antibody in bile coincided with the termination of virus excretion in faeces. These experiments confirm that bile IgX of the duck can function as antibody in response to influenza A viruses, and that its activity appears to be independent of serum IgM. Its possible relevance in determining survival of virus in the intestine is discussed.

Bile immunoglobulin of the duck (Anas platyrhynchos). I. Preliminary characterization and ontogeny.

Immunoglobulin (Ig) of a single class was found in duck (Anas platyrhynchos) bile. Its molecular weight was 890,000; serum IgM was 800,000. Heavy chains were 75,000 for bile Ig, 86,000 for IgM, 67,000 for 7.8S IgG and 37,000 for 5.7S IgG. Antigenic comparison showed that bile Ig resembled IgM but carried additional determinants. The ontogeny of bile Ig was distinct from that of serum IgM and IgG. Thus, duck bile Ig appears to be an IgM-like molecule secreted independently of serum Ig.

Hepatitis B-antigen subtypes in Australia as detected by radioimmunoassay.

The distribution of the major subtypes of hepatitis B surface antigen (HBsAg) was examined in asymptomatic white Australian blood donors and patients with liver disease to attempt ot assess the biological significance of these subtypes in this relatively homogeneous Caucasian population. Since previous studies have shown a very low prevalence of HBsAg in white Australians, a highly sensitive solid phase radioimmunoassay (RIA) was developed and used to subtype the antigen. A total of 46 samples of hepatitis B-antigen positive sera, obtained from 21 asymptomatic volunteer blood donors and 25 patients with liver disease, were tested. Sixteen of these 21 asymptomatic carriers were shown to have subtype "ad" whereas only seven of the patients with liver disease had this subtype. This difference was significant (P less than 0.005) and supports the view that subtype "ad" is associated with a carrier state and subtype "ay" with liver disease in Australia.

Guillain Barré syndrome during the pre-icteric phase of acute type B viral hepatitis.

A 54-year-old man presented with the Guillain Barré syndrome (GBS) during the pre-icteric phase of acute type B viral hepatitis. This neurological syndrome has been infrequently described in the clinical course of viral hepatitis but only once previously during the prodromal period. Deposition of circulating immune complexes of the HBsAg have been implicated in the pathogenesis of arthritis, nephritis and polyarteritis associated with type B viral hepatitis. Although the relationship of GBS to type B viral hepatitis is uncertain, a similar immunopathological mechanism may be involved.