Selective cyclooxygenase-2 inhibition: a target in cancer prevention and treatment

A major goal in the area of cancer prevention and treatment is to make rational use of defined molecular targets in order to block carcinogenesis. Studies conducted in experimental animal models for many human cancers, including those of lung, skin, mammary gland, urinary bladder, colon, and pancreas, have demonstrated that carcinogenesis often may be inhibited by the administration of a highly diverse group of biologic and chemical agents. One very promising and well-studied target is cyclooxygenase (COX)-2. Interestingly, a number of cancers appear to overexpress the COX-2 enzyme, which may play several roles in carcinogenesis. Recent clinical studies have demonstrated the effect of COX-2 inhibitors in the treatment of familial adenomatous polyposis, a genetic disorder that increases the risk for developing colorectal cancer. Ongoing clinical trials with COX-2 inhibitors will increase our understanding and may give us profound insights into the general applicability of this new targeted approach for cancer control.     

Treatment of Plasmodium falciparum malaria with a combination of amodiaquine and tetracycline in Central Thailand

A combination of the drugs amodiaquine and tetracycline was used in a clinical trial at Phrabuddhabat Hospital in Central Thailand for treating Plasmodium falciparum malaria. Of the 51 patients who completed the 28-day follow-up, 49 (96%) were cured; in two cases the parasitaemia was cleared within seven days of initial therapy but returned within 28 days (R_I response). Only one patient experienced a mild and transient side effect of nausea. The treatment regimen was cheap and the drugs are readily available commercially. Results of this study suggest that amodiaquinetetracycline combination offers a practical, safe and highly effective method for treating uncomplicated falciparum malaria.     

The administration of cortisone to female B6A mice during their immune adaptive period causes anovulation and the formation of ovarian cysts

PROBLEM: Female mice that are injected with estradiol-17beta (E2) and testosterone during the 7-day immune adaptive period are infertile at adulthood. To determine whether the resultant infertility can be caused by steroids other than estrogens/ androgens, this study examined the effect of injecting cortisone, alone, and in combination with E2 and testosterone, on reproductive function. METHOD OF STUDY: Neonatal (C57BL/6J x A/J)F1 B6A female mice were injected from 3 to 6 days of age with sesame oil:ethanol (9:1; v:v), alone, or containing 20 microgg cortisone acetate, 20 microg E2, or 20 microg testosterone. Two additional groups were given 20 microg cortisone acetate in combination with 20 microg E2 or 20 microg testosterone. At adulthood the animals were killed, the stage of vaginal estrus determined, the ovaries examined for the presence of corpora lutea and follicular cysts, and circulating levels of progesterone, E2, and testosterone were measured by radioimmunoassay (RIA). RESULTS: It was found that injections of cortisone seriously compromise reproductive development. For example, 11% of cortisone-injected animals had ovaries that lacked corpora lutea. In addition, 39% of cortisone-injected females had ovaries with follicular cysts. Cortisone-injected females also had low levels of circulating progesterone (18 ng/mL versus 30 ng/mL for the sesame oil-injected females). CONCLUSION: It is concluded that the deleterious effect of steroids on reproductive function, when administered during the immune adaptive period, is not restricted to estrogens and androgens. It is proposed that injections of cortisone alter T-lymphocyte subsets, which contributes to anovulation and the production of follicular cysts.     

Chromosomal abnormalities in amniotic fluid cell cultures: a comparison of apparent pseudomosaicism in Chang and RPMI-1640 media

The finding of chromosome mosaicism is one of the most difficult problems in fetal chromosome analysis. Whether the finding indicates true mosaicism or pseudomosaicism must be investigated. Studies detailing the incidence of true mosaicism and pseudomosaicism have been reported (Hsu & Perlis 1984, Bui et al. 1984, Worton & Stern 1984) but do not correlate pseudomosaicism with any particular type of culture media. Benn & Hsu (1985) compared cell growth and chromosome abnormalities in amniotic fluid cell cultures grown in Chang medium and RPMI-1640 medium and found no statistically significant difference in the rate of abnormalities in the two media. We have previously shown that Chang medium exhibited more abnormalities which were not verified in second and third cultures (Masia et al. 1986). In the current study we examined 212 cases grown in both Chang and RPMI-1640 media, and compared apparent single and multiple cell pseudomosaic abnormalities to medium type. The number of observed abnormalities was 22, occurring in 19 of the cases studied. Apparent pseudomosaic chromosome anomalies were observed in 18 Chang cultures and in 4 RPMI-1640 cultures. Statistical analysis found significant correlation between medium type and the degree of observed pseudomosaic cells. We conclude that the rate at which pseudomosaic cells are observed is partly a function of medium type, and in our laboratory Chang medium caused apparent pseudomosaicism at a greater level than RPMI-1640 medium.     

Distribution of autosomal fragile sites in specimens cultured for prenatal fragile X diagnosis

We reviewed the distribution of autosomal fragile sites (FS) and spontaneous chromosome breaks or gaps (CB) at chromosome locations other than those recognized as FS from 100 amniotic fluid samples (AF), 19 chorionic villus samples (CVS), and 5 percutaneous umbilical blood samples (PUBS) referred for fragile X [fra(X)] analysis. We present data on the degree of expression of autosomal fragility in AF, CVS, and PUBS samples, and the relationship between degree of expression and induction system. The most common observed FS were: 3p14, 9p32, and 6q26 in AF; 9q32, 3q27, and 8q22 in CVS; and 3p14, Xq22, and 16q23 in PUBS cases. Distribution of FS and CB, when compared by induction system, was not found to be identical. Our data also indicate that the presence of any particular FS cannot be used as an indicator for the effectiveness of the fra(X) induction system in prenatal samples.     

Improved prenatal detection of fra(X)(q27.3): methods for prevention of false negatives in chorionic villus and amniotic fluid cell cultures

The reliable detection of fra(X)(q27.3) in prenatal samples is important for providing genetic counseling. We have identified 5 new cases of prenatal fragile X [fra(X)] detection in 3 chorionic villus sample (CVS) and 2 amniotic fluid (AF) cell cultures. In 4 of the 5 cases, either excess thymidine (THY) or a combination of THY and 5-fluorodeoxyuridine (FUdR) was clearly superior to FUdR alone as fra(X) inducers. Amniocytes from one case were cultured only in RPMI-1640 and later exposed to FUdR or THY separately. They showed only 2% fra(X) while parallel cultures initiated in Chang medium and incubated in RPMI for at least 7 days (recovery) before fra(X) induction exhibited strikingly increased fra(X) frequencies. Chang medium alone will not allow fra(X) induction in AF (Jenkins EC, Brown WT [1986]: "Genetic Disorders and the Fetus: Diagnosis, Prevention and Treatment." New York: Plenum Press, pp 185-204). Now, using CVS cells, we report that only 1% and 0% fra(X) were detected using FUdR or THY in cells cultured in RPMI for 4 days after removal from Chang medium. Cells with 7 days "recovery" in RPMI exhibited increases from 2 to 6%. Therefore, we have found that Chang medium is very helpful when the appropriate recovery time in another medium is allowed before fra(X) induction. Some false negative reports can be attributed to: induction in Chang medium alone; lack of sufficient recovery time after initiating cells in Chang before induction; and unavailability of the excess THY fra(X) induction system.(ABSTRACT TRUNCATED AT 250 WORDS)     

The differential effect of injecting estradiol-17beta, testosterone, and hydrocortisone during the immune adaptive period on the fertility of female mice

PROBLEM: Female mice injected with estradiol-17beta (E2) and testosterone during the immune adaptive period are infertile as adults. Study 1 examined the effect of the day of injection of E2 and testosterone on the incidence of infertility in two strains of mice. Study 2 examined the effect of hydrocortisone on E2-induced infertility. METHOD OF STUDY: Study 1: Neonatal (C57BL/6J x A/J)F1 B6A and (C3H/HeJ x 129J)F1 C31 female mice were injected from 0 to 3 and from 3 to 6 days of age with either 20 microg E2 or 20 microg testosterone. Animals were tested for fertility by mating with fertile males. Study 2: Neonatal B6A females were injected with 20 microg E2 with/without 1000 microg hydrocortisone on days 1, 3, 5, 7, and 10. At adulthood, ovaries were examined for the presence of corpora lutea (CLs). RESULTS: Study 1: The incidence of E2-induced infertility in adult B6A and C31 females decreased over three consecutive matings. In contrast, the incidence of testosterone-induced infertility in adult B6A and C31 females increased. E2 caused the highest incidence of infertility in C31 females when injected prior to 3 days of age. In B6A mice, E2 caused the highest incidence of infertility when injected after 3 days of age. Study 2: When hydrocortisone was injected with E2, 90% of the B6A females had ovaries with CLs at 100 days of age. Without hydrocortisone, only 16% of the B6A females injected with E2 had ovaries with CLs. CONCLUSION: Study 1: The incidence of infertility caused by injections of E2 is dependent on the strain of mice and the day(s) injected. The incidence of infertility caused by injections of testosterone is independent of the strain of mice. Study 2: Hydrocortisone prevents E2-induced infertility. It is proposed that injections of E2 during the immune adaptive period alter T-cell maturation, which contributes to E2-induced infertility.