New candidate vaccines against blood-stage Plasmodium falciparum malaria: prime-boost immunization regimens incorporating human and simian adenoviral vectors and poxviral vectors expressing an optimized antigen based on merozoite surface protein 1.

Although merozoite surface protein 1 (MSP-1) is a leading candidate vaccine antigen for blood-stage malaria, its efficacy in clinical trials has been limited in part by antigenic polymorphism and potentially by the inability of protein-in-adjuvant vaccines to induce strong cellular immunity. Here we report the design of novel vectored Plasmodium falciparum vaccines capable of overcoming such limitations. We optimized an antigenic insert comprising the four conserved blocks of MSP-1 fused to tandemly arranged sequences that represent both allelic forms of the dimorphic 42-kDa C-terminal region. Inserts were expressed by adenoviral and poxviral vectors and employed in heterologous prime-boost regimens. Simian adenoviral vectors were used in an effort to circumvent preexisting immunity to human adenoviruses. In preclinical studies these vaccines induced potent cellular immune responses and high-titer antibodies directed against MSP-1. The antibodies induced were found to have growth-inhibitory activity against dimorphic allelic families of P. falciparum. These vectored vaccines should allow assessment in humans of the safety and efficacy of inducing strong cellular as well as cross-strain humoral immunity to P. falciparum MSP-1.

Inhibitory activity of tea polyphenol and Hanseniaspora uvarum against Botrytis cinerea infections.

AIMS: To investigate the effect of tea polyphenol (TP) and Hanseniaspora uvarum alone or in combination against Botrytis cinerea in grapes and to evaluate the possible mechanisms involved. METHODS AND RESULTS: TP alone was effective in controlling grey mould in grape at all concentrations. TP at 0.5 and 1.0% in combination with H. uvarum (1 x 10(6) CFU ml(-1)) showed a lower infection rate of grey mould. TP at 0.01% or above significantly inhibited the spore germination of B. cinerea. TP at 0.1% showed inhibition ability on mycelium growth of B. cinerea. The addition of TP did not affect the growth of H. uvarum in vitro and significantly increased the population of H. uvarum in vivo. CONCLUSIONS: TP exhibited an inhibitory effect against B. cinerea and improved the biocontrol efficacy of H. uvarum. The inhibitory effects of spore germination and mycelial growth of B. cinerea and the increased populations of H. uvarum in vivo may be some of the important mechanisms of TP. SIGNIFICANCE AND IMPACT OF THE STUDY: The results suggested that TP alone or in combination with biocontrol agents has great potential in the commercial management of postharvest diseases of fruits.

Inhibitory activity of tea polyphenol and Candida ernobii against Diplodia natalensis infections.

AIMS: To investigate the effect of tea polyphenol (TP) and Candida ernobii alone or in combination against postharvest disease (Diplodia natalensis) in citrus fruit and to evaluate the possible mechanisms involved. METHODS AND RESULTS: TP at concentrations of 0.1%, 0.5% and 1.0% alone, or in combination with C. ernobii (1x10(6) CFU ml(-1)), showed a lower infection rate of stem-end rot. TP at the concentration of 0.5% or above significantly inhibited the spore germination of D. natalensis. TP at the concentration of 1.0% showed inhibitary ability on mycelium growth of D. natalensis. The addition of TP did not affect the growth of C. ernobii in vitro and significantly increased the population of C. ernobii in vivo. CONCLUSIONS: TP exhibited an inhibitory effect against D. natalensis and improved the biocontrol efficacy of C. ernobii. It was direct because of the inhibitory effects of TP on spore germination and mycelial growth of D. natalensis in vitro and indirect because of the increased populations of C. ernobii in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: The results suggested that TP alone or in combination with biocontrol agents has great potential in commercial management of postharvest diseases in fruits.

Frequent detection of tumor cells in hematopoietic grafts in neuroblastoma and Ewing's sarcoma.

Many poor-risk neuroblastomas and tumours of the Ewing's sarcoma family (ET) recur despite autologous transplants. Recurrence may be due to tumor cells contained in the BM harvests or PBSC harvests. The objectives of this prospective study were to: (1) determine the incidence and degree of tumor cell contamination in paired BM and PBSC harvests; and (2) determine the efficacy of tumor cell purging by immunomagnetic CD34+ cell selection. 198 samples from 11 consecutive patients with neuroblastoma or Ewing's sarcoma were analyzed. We assayed tumor contamination by RT-PCR assay for PGP 9.5, plus immunohistochemistry for neuroblastoma-specific antigens (the latter in neuroblastoma only). None of these patients had tumor cells detected in their BM by clinical histology immediately before BM or PBSC harvests. However, 82% of PBSC and 89% of backup BM harvests were contaminated with tumor by RT-PCR and/or immunocytochemistry assays. Unselected PBSC and BM harvests contained similar quantities of tumor cells (median, approximately 200000 cells). Cyclophosphamide plus G-CSF mobilization did not affect the incidence or level of contamination in PBSC harvests, as compared to blood obtained before mobilization. Immunomagnetic CD34+ cell selection depleted tumor cells by a median of 3.0 logs for PBSC, and 2.6 logs for BM harvests.

Dose-intensive vinorelbine with concurrent granulocyte colony-stimulating factor support in paclitaxel-refractory metastatic breast cancer.

PURPOSE: We evaluated weekly single-agent intravenous (IV) vinorelbine as salvage therapy for metastatic breast cancer. After the first five patients, all received elective growth factor support with granulocyte colony-stimulating factor (G-CSF; filgrastim) in an attempt to maximize delivered dose-intensity (DDI). Objective tumor response, DDI, and toxicity were assessed, as well as time to progression (TTP) and survival. PATIENTS AND METHODS: This single-center nonrandomized trial enrolled 40 patients. Anthracycline exposure and subsequent progression were common to all patients, and 38 of 40 were paclitaxel-refractory. Vinorelbine was given initially at 30 mg/m2/wk, then at 35 mg/m2/wk in a phase I/II design, which involved first intermittent (6 days of 7) and then continuous (daily) administration of G-CSF at 5 micrograms/kg. RESULTS: The maximum-tolerated starting dose was 35 mg/m2/wk with continuous G-CSF support. The mean DDI was 27.7 mg/m2/wk for all patients. There were two complete responses (CRs) and eight partial responses (PRs) in 40 assessable patients for an overall response rate of 25% (95% confidence interval [CI], 13% to 41%). The median TTP was 13 weeks and median survival time 33 weeks. The dose-limiting toxicity was neutropenia, with dose delay or reduction required in 14 of 27 patients entered at 35 mg/m2. Febrile neutropenia that required hospitalization was unusual (three of 40 patients, 8%). There were no treatment-related deaths. Grade 3/4 thrombocytopenia occurred in nine patients (23%) and 26 patients (65%) required RBC transfusions for anemia. Seven patients (18%) had reversible grade 3/4 nonhematologic complications, primarily related to neurotoxicity. Grade > or = 3 mucositis was absent. CONCLUSION: Concurrent administration of weekly vinoralbine and daily G-CSF is feasible and permits an increase in DDI for vinorelbine of 43% to 76% over that reported in series without growth factor support. The response rate, TTP, and survival data are encouraging for therapy given to heavily pretreated patients with metastatic breast cancer. Vinorelbine is not cross-resistant with paclitaxel and should be considered for further trials in the dose-intensified mode made possible by G-CSF, alone or combined with other agents.

Maternal serum creatine kinase does not predict tubal pregnancy.

PURPOSE: Our purpose was to validate prospectively the predictive value of maternal serum creatine kinase in the evaluation of ectopic pregnancy. METHODS: Fifty-one consecutive pregnant first-trimester patients who presented for suspected abnormal pregnancy were enrolled. Maternal serum samples were obtained and assayed for creatine kinase. Patients were subsequently evaluated for abnormal pregnancy by serial quantitative hCG levels, transvaginal ultrasonography, and surgery when appropriate. A receiver operating characteristic (ROC) curve was generated comparing intrauterine to extrauterine (ectopic) pregnancy. RESULTS: Of 51 patients, 18 had an ectopic pregnancy, 16 had a spontaneous abortion, and 17 had an ongoing intrauterine pregnancy. The ROC curve revealed that maternal serum creatine kinase had no ability to predict ectopic pregnancy. CONCLUSIONS: Maternal serum creatine kinase is not a reliable predictor of tubal pregnancy.

Evaluation of patients with abnormal uterine bleeding.

An accurate, efficient diagnosis of disorders responsible for abnormal uterine bleeding depends on a systematic consideration of all the possible causes. Careful history and physical and pelvic examinations provide the framework for evaluation. Many adjunctive diagnostic aids can be used to evaluate women with abnormal uterine bleeding. These tests include complete blood cell count, pregnancy test, hormone levels (estradiol, progesterone, follicle-stimulating hormone, luteinizing hormone, prolactin, testosterone, dehydroepiandrosterone sulfate), thyroid function tests, liver function tests, and coagulation profile. The need for these tests are individualized and based primarily on the patient's presentation. In women of reproductive age a complication of pregnancy should always be ruled out. Ectopic pregnancies can be life threatening. The prognosis in women with trophoblastic disease can be altered by a delay in establishing the correct diagnosis. Ultrasonographic studies, particularly transvaginal ultrasonography and hysteroscopy, have played an increasing role in the evaluation of patients with abnormal uterine bleeding over the past decade, especially for cases of intrauterine space-occupying lesions, including endometrial polyps, submucosal myomas, and retained placental fragments. Suspicion of reproductive tract malignancies is heightened in patients > 35 years old, those with a history of oligoovulation or anovulation suggestive of long-term unopposed estrogen exposure, those who are obese, and those who do not respond to first-line medical management. Diagnostic techniques available for the evaluation of these cases include endometrial biopsy, dilatation and curettage, transvaginal ultrasonography, and hysteroscopy. These procedures not only allow accurate diagnosis but may permit immediate therapeutic measures to be taken when organic causes are discovered. In summary, the key to the evaluation of abnormal uterine bleeding is a through history and physical and pelvic examinations governed by the differential diagnosis of excessive uterine bleeding and the selected use of adjunctive diagnostic tests and procedures only when absolutely necessary.

Comparison of immunosuppressive properties of hydatidiform mole decidua and trophoblast extracts.

PROBLEMS: The immunologic privilege afforded the fetus relies upon immunoregulation within the maternal-fetal interface. Trophoblast and decidua-derived immunoregulatory factors enforce this privilege by locally suppressing maternal responses to trophoblast antigens. The relative contribution of trophoblast or decidua immunosuppressive factors to pregnancy immunotolerance are not well characterized. The purpose of this study was to compare the suppressive effects of hydatidiform mole trophoblast and decidua extracts on interleukin-2-dependent proliferation. METHOD: Tissue extracts were prepared from hydatidiform mole trophoblast and decidua following uterine evacuation. Samples were submitted to interleukin-2-dependent and -independent cell proliferation assays. RESULTS: Hydatidiform mole trophoblast extract significantly (P < 0.05) suppressed interleukin-2-dependent proliferation but did not affect interleukin-2-dependent cell proliferation. In contrast, molar decidua extract suppressed both cell lines. CONCLUSIONS: Human hydatidiform mole trophoblast contains factor(s) that specifically abrogate interleukin-2-dependent clonal expansion of murine cytotoxic T-cells. In contrast, extracts of molar decidua suppressed both interleukin-2-dependent and -independent responses. This indicates that the trophoblast antagonizes critical interleukin-2-mediated immunologic responses, but that the decidua uses nonspecific antiproliferative mechanisms for immunoregulation.

Plasmodium yoelii: the role of the individual epidermal growth factor-like domains of the merozoite surface protein-1 in protection from malaria.

The merozoite surface protein-1 (MSP-1) is a leading candidate for a vaccine targeted at the erythrocytic stages of plasmodial parasite development. Recently, there has been increasing interest in this polypeptide, particularly in the carboxyl-terminal EGF-like domains. We have previously shown that this region from Plasmodium yoelii, when expressed in native configuration, could immunize mice against an otherwise lethal challenge infection. In this model system, protection appears to be predominantly mediated by antibodies. In all rodent immunization studies to date, however, the immunogen has contained both of the postulated EGF-like domains. We report here on the efficacy of immunization with the individual EGF-like domains from P. yoelii in elicitation of a protective host response. Although all animals developed some level of antibody in response to the various immunogens, only those animals immunized with both EGF-like domains produced antibodies which could recognize the native MSP-1 molecule. Antibodies generated against the individual EGF-like domains did cross-react with the double EGF-like domain structure, suggesting that the immunogens had retained elements of native configuration. In addition, only those animals which generated antibodies capable of recognizing native MSP-1 showed any level of protection from challenge infection. These results suggest that determinants unique to the double EGF-like domain structure may be necessary for the generation of antibodies specific for the native configuration of MSP-1 and that these antibodies may play a significant role in protection.

Humoral response to a carboxyl-terminal region of the merozoite surface protein-1 plays a predominant role in controlling blood-stage infection in rodent malaria.

The developmental stages of malaria parasites that infect E are responsible for the morbidity and mortality associated with this disease. One of the leading candidates for a blood-stage vaccine against malaria is a surface protein of merozoites, the infectious stages for E, designated merozoite surface protein-1 (MSP-1). The rodent malarial parasite Plasmodium yoelii yoelii (Py) has provided a model system for the study of this Ag, and previous studies from our laboratory had demonstrated that the carboxyl-terminal, cysteine-rich region of MSP-1, when expressed in a native configuration, could immunize mice against a normally lethal challenge infection with Py. We have now prepared a new fusion construct with the glutathione-S-transferase gene of Schistosoma japonicum joined to the carboxyl-terminal 11 kDa of Py MSP-1. This includes only the two epidermal growth factor-like domains of the MSP-1 protein. When expressed in recombinant Escherichia coli, the fusion protein induces a strong protective response in BALB/c mice as judged by the resistance of immunized animals to a virulent challenge infection. Moreover, we demonstrate that this resistance can be transferred passively by immune serum or by purified Ig, establishing a significant role for humoral immunity in protection. No role for CD4+ or CD8+ T cells could be identified in the first 12 days after challenge infection in immune mice selectively depleted of these cells; however, after this time, parasitemias gradually increased in mice depleted of CD4+ T cells, suggesting an active host response is necessary to completely eliminate the infection.

Sequence heterogeneity of the C-terminal, Cys-rich region of the merozoite surface protein-1 (MSP-1) in field samples of Plasmodium falciparum.

Recent results with primate plasmodia and rodent models of infection have focused attention on the C-terminal region of the merozoite surface protein-1 (MSP-1) as one of the leading candidates for vaccination against the erythrocytic stages of malaria. However, sequence heterogeneity of this region may compromise its use as a vaccine candidate. While the C-terminal region of MSP-1 from the two prototypic alleles of P. falciparum has been shown to be relatively conserved in laboratory-maintained strains, little data exist on sequence heterogeneity of this region in field isolates from diverse geographic areas. To address this question, DNA encoding the C-terminal, Cys-rich region of P. falciparum MSP-1 from field samples was analyzed by a polymerase chain reaction (PCR)-direct sequencing method. Sequence data were consistent with those obtained from laboratory-maintained strains. In 15 isolates from Africa, Asia and Latin America, only a few nucleotide changes were found leading to amino-acid alterations at four positions out of 102 residues. All the variations corresponded to the predicted amino-acid sequence of the other prototype, suggesting that these changes were possibly due to allelic recombinations. The four changes were E-->Q at position 1644 and TSR-->KNG, or KNG-->TSR at positions 1691, 1700 and 1701. Thus, only three patterns of the C-terminal, Cys-rich region of MSP-1, E-TSR, Q-KNG and Q-TSR, were detected. All the Cys residues were conserved. These results support the potential utility of the C-terminal region of MSP-1 as a vaccine candidate.

Laparoscopically directed ovarian cystectomy in premenopausal women. Impact of surgical experience on surgical time.

The purpose of this study was to correlate surgical experience with operating efficiency. A retrospective review of 303 operative laparoscopic procedures was performed during a 48-month interval and during the acquisition of surgical skills by one faculty member. Population demographics and surgery time were evaluated in 41 cases (13.5%) of ovarian cystectomy. Patients were categorized into fertility-related or gynecologic indications for surgery. Surgical time for successful laparoscopically directed resection of benign ovarian cysts was significantly reduced over the study interval (P = .008). Endometrioma was the most common pathologic finding in women with impaired fertility, and benign epithelial tumors were the lesion encountered most commonly in gynecologic patients. Benign teratoma occurred infrequently in both groups. No malignancy was observed in this group of premenopausal women, who had unilocular cysts less than 8 cm in diameter. Reduction in surgical time for laparoscopically directed ovarian cystectomy occurs after experience is gained by repeated application of the technique.

Elevated luteinizing hormone on the day of human chorionic gonadotropin administration does not reduce cycle fecundity in a low-dose flare-up in vitro fertilization protocol.

OBJECTIVE: To determine if elevated LH at the time of hCG administration occurs and adversely affects success in a low-dose gonadotropin-releasing hormone analogue (GnRH-a) flare-up protocol in hMG-stimulated IVF cycles. DESIGN: Pearson correlation matrix analysis of hormonal, gamete, and clinical data derived from 203 consecutive IVF cycles was performed. All patients were treated with low-dose GnRH-a (250 micrograms SC leuprolide acetate) and hMG. In 203 consecutive IVF cases, serum was obtained on the day of hCG administration and assayed for E2, LH, and P. These data were correlated with peak E2, number of follicles, oocytes, embryos, and conceptions. Additionally, patients with elevated LH were compared with the nonelevated LH group. RESULTS: Twenty six women had LH > 35 mIU/mL (mean +/- SEM; 51.1 +/- 1.9) and five pregnancies (cycle fecundity 19.2% per retrieval). One hundred seventy-seven patients had LH < 35 mIU/mL (16.3 +/- 0.5) and 25 pregnancies (cycle fecundity 14.1%). There were no differences in the mean P (1.0 +/- 0.1 ng/mL, conversion factor to SI unit, 3.81) and E2 (1,672 +/- 144 pg/mL, conversion factor to SI unit, 3.671) of the former group compared with the P (1.1 +/- 0.07 ng/mL) and E2 (1,456 +/- 69 pg/mL) of the latter group. There was no correlation with the number of follicles, oocytes, embryos, pregnancies, E2, or P to LH concentration (rmax = 0.132). CONCLUSION: In a low-dose, GnRH-suppression, IVF induction protocol, elevated LH occurs in a small subset (13%) of women at the time of hCG administration. This event does not appear to alter cycle fecundity nor induce premature luteinization.

Progesterone concentration as a predictor of pregnancy normalcy is the most useful when hCG levels are less than 2000 mIU/mL.

OBJECTIVE: Measurements of serum progesterone to predict early gestational normalcy have been found to be as predictive as serial hCG titers. Since ultrasound would be the diagnostic tool of choice if hCG was > 2000 mIU/ml, the purpose of the present study was to determine the best predictive value of a single progesterone measurement when hCG levels were < 2000 mIU/ml. DESIGN: Relative operating characteristic analysis of progesterone level as a predictor of early gestational normalcy when hCG is < 2000 mIU/ml. MATERIALS AND METHODS: Ninety-three pregnant patients that conceived spontaneously were evaluated with progesterone measurements when the patient's hCG was < 2000 mIU/ml. Two-by-two contingency tables were constructed that compared pregnancy outcome with multiple discriminatory serum progesterone concentrations between 0 and 38 ng/mL. From these tables, a relative operating characteristic (ROC) curve was generated to compare the sensitivity and false-positive rates. RESULTS: Of a total of 93 pregnancies, 27 had a normal outcome and 66 had an abnormal outcome. The ROC curve indicated that a serum progesterone concentration of 12 ng/ml had the highest sensitivity associated with the lowest false-positive rate. The area under the curve was equal to 0.941 +/- 0.024. This observation was compared to our previously reported data of progesterone levels that included hCG levels > 2000 mIU/ml, yielding an area under the curve of 0.772 +/- 0.053. Calculation of the critical ratio z revealed that there is a significant improvement in the predictive value of progesterone when hCG is < 2000 mIU/ml (P < 0.005). CONCLUSION: A single serum progesterone level has a better predictive value of pregnancy normalcy when hCG measurements are < 2000 mIU/ml.

Immunosuppression by conditioned media derived from a cloned choriocarcinoma cell line in serum-supplemented and defined media.

PROBLEM: Immunosuppressive factor(s) of trophoblast origin may contribute to the immunological privilege afforded the fetal allograft. Characterization of these immunoregulators in humans has been impeded by a lack of sufficient quantities of early gestational trophoblast for experimentation. METHOD: In this study, a cloned choriocarcinoma cell line (BeWo) was evaluated as an experimental model of trophoblast-derived immunoregulation. BeWo cells were cultured in both serum-supplemented (15% fetal bovine serum; FCS-CM) and serum-free (10% bovine serum albumin, BSA-CM; 0.01% gelatin, Gel-CM) media. Immunosuppressive activity was determined through the use of interleukin-2-dependent (CTLL-2) and -independent (LBRM) cell lines. Human chorionic gonadotropin (hCG) levels were determined by an immunoradiometric assay, and cellular morphology was assessed by light microscopy. RESULTS: In the serum-supplemented cultures, a portion of cells underwent transformation from single nucleated cytotrophoblast to multinucleated syncytiotrophoblast during days 1 to 5 of culture and was accompanied by a rise in hCG. Serum-free cultures were characterized as islands of cytotrophoblast and did not exhibit differentiation. FCS-CM suppressed CTLL-2 and LBRM proliferation with estimated EC50 values of 415 and 280 micrograms protein/mL, respectively. Gel-CM suppressed CTLL-2 and LBRM proliferation with EC50 values of 12 and 7 micrograms protein/mL, respectively. BSA-CM suppressed CTLL-2 proliferation with an EC50 of 132 micrograms protein/mL, but failed to suppress LBRM proliferation below 50% of control. CONCLUSION: These results suggest that the BeWo cell line is a promising model for the study of trophoblast-derived suppressive factors and that these factors can be generated in serum-free medium.

Laparoscopic Pomeroy tubal ligation as a teaching model for residents.

We reviewed our preliminary experience with laparoscopically directed bilateral midtubal resection for tubal ligation (endoscopic Pomeroy) as a potential teaching tool for the acquisition of endoscopic skills during residency training. Thirty-five laparoscopic Pomeroy and 206 banding procedures were reviewed. Age, parity and weight were similar in the two groups. The operative time for banding was reduced slightly after experience with > 10 procedures. In contrast, the operative time for laparoscopic Pomeroy procedures decreased dramatically after individual experience with only a few (< or = 5) procedures. The mean operative time for the Pomeroy group approached that of the more traditional banding technique at five procedures. Our data indicate that laparoscopic Pomeroy sterilization can be an effective teaching tool for operative laparoscopy, allowing residents to repeatedly perform an easy and safe procedure that incorporates basic techniques. Advanced operative endoscopic procedures could then be taught more efficiently after the acquisition of basic skills.

PIP: 25 gynecology residents performed laparoscopic banding (tubal rings) sterilization on 206 women and laparoscopic Pomeroy sterilization on 35 women, all of whom underwent tubal sterilization at the University of Mississippi Medical Center between September 1988 and October 1990. Three faculty members and a fourth year resident retrospectively analyzed the data of both groups to determine the effect of the Pomeroy method on operative laparoscopic skills acquired by the residents during training. Both groups were similar in age, parity, and weight. Each of the 23 residents performed 1-22 laparoscopic banding procedures. As residents gained experience, the time to perform both banding and Pomeroy methods decreased significantly (p = 0.026). After a resident had conducted 5 Pomeroy procedures, the surgery time had approached that of laparoscopic banding. These findings show that gynecology faculty can use laparoscopic Pomeroy tubal ligation as an effective teaching tool for laparoscopy by providing residents an opportunity to repeatedly perform an easy and safe procedure that includes basic techniques. After developing the basic skills, the residents can then learn more efficiently advanced operative endoscopic techniques.

Immunosuppression by hydatidiform mole trophoblast is neutralized by monoclonal antibodies to beta-interferon.

PROBLEM: In sheep and cattle, trophoblast-derived interferons serve as signals for the maternal recognition of pregnancy and may regulate the immunologic relationship between the fetus and mother. METHOD: In this study, soluble extracts prepared from human hydatidiform mole decidua (DE) and trophoblast (HME) were screened for immunosuppressive activity using an interleukin (IL)-2-dependent T-cell line (CTLL2). Antibody neutralization studies were performed with monoclonal antibodies to alpha- and beta-interferon (IFN). RESULTS: HME suppressed (P < 0.05) IL-2-stimulated (2 IU/well) CTLL2 proliferation at doses ranging from 500 (52 +/- 2% of control) to 100 (74 +/- 5%) micrograms/ml concentrations. DE also suppressed (P < or = 0.05) CTLL2 proliferation in a dose-related fashion from 500 (20 +/- 6% of control) to 100 (71 +/- 8%) micrograms/ml doses. Preincubation with the alpha- and beta-IFN antibody preparations had no effect on CTLL2 suppression by the DE sample. In contrast, the beta-IFN antibody partially neutralized the suppressive activity of HME at each of the dilutions tested. The monoclonal antibody to alpha-IFN failed to neutralize HME suppression at any of the doses tested. CONCLUSIONS: These results suggest that hydatidiform mole trophoblast produces a beta-IFN-like macromolecule that may abrogate maternal rejection responses that are harmful to the developing fetal allograft.

Gestational age correlates with immunosuppressive properties of hydatidiform mole pregnancies.

PROBLEM: Soluble trophoblast extracts (HME) from some human hydatidiform mole pregnancies suppress IL-2-dependent T-cell proliferation, while others express no immunosuppressive bioactivity. This study was designed to determine if suppression by HME was correlated with gestational age, uterine size, or hCG secretion. METHOD: Soluble extracts were prepared from nine hydatidiform mole trophoblast samples and screened for immunosuppressive activity using a murine cytotoxic T-cell proliferation assay (CTLL-2). Gestational ages were determined from last menstrual cycle and uterine size was estimated at the time of surgery. Serum samples were collected prior to uterine evacuation and were assayed for human chorionic gonadotropin (hCG). RESULTS: Four of nine HME samples significantly (P < 0.05) suppressed CTLL2 proliferation, while five exhibited no suppressive activity. A strong positive correlation (r = 0.639) was noted for the relationship between gestational age of the molar pregnancies and interleukin-2 (IL-2)-stimulated CTLL2 proliferation (expressed as % of control) in the presence of HME (500 micrograms/mL). This indicates that HME suppression of CTLL2 proliferation is highest in early gestation and then declines with increasing gestational age. A similar correlation was observed between estimated uterine size at surgery and CTLL2 proliferation with added HME, although the association was not as strong (r = 0.359). No association was noted between hCG levels and CTLL2 proliferative responses (r = -0.091). CONCLUSIONS: The results of this study suggest that production of immunosuppressive factors by hydatidiform mole trophoblast is developmentally regulated, and decreases with advancing gestation.

Regulation of early gestational corpus luteum function in spontaneous and follicular stimulated conceptions.

OBJECTIVE: To determine the regulatory role of hCG on P secretion in normal and abnormal (abortive and ectopic) first trimester pregnancies. STUDY DESIGN: The number of doublings of hCG per day (1/DT; reciprocal of hCG doubling time) was correlated with serum P using linear and nonlinear models in normal intrauterine pregnancies, spontaneous abortions, and ectopic pregnancies (EPs) conceived spontaneously or after clomiphene citrate (CC). RESULTS: Linear correlations between P and 1/DTs of hCG were poor. In contrast, nonlinear modeling with a hyperbolic curve fit the data well and allowed all of the data to be included for analysis regardless of the pregnancy type. Furthermore, this model could be used to explain the differential P concentrations seen in normal and abnormal first trimester pregnancies. The nonlinear hyperbolic model demonstrated that follicular events determine the maximal P production during early gestation. Human chorionic gonadotropin 1/DTs approximately equal to 0.5 sustain maximal P production. Progesterone production is then sustained by the rate of change of hCG. CONCLUSION: Nonlinear correlation analysis suggests that P production in early gestations is regulated by prior follicular events and the rate of hCG production.

Taxol arrests the development of blood-stage Plasmodium falciparum in vitro and Plasmodium chabaudi adami in malaria-infected mice.

Taxol, a natural product used to treat a variety of human cancers, is shown here to be extremely effective against chloroquine- and pyrimethamine-resistant malaria parasites. Addition of Taxol (1.0 microM) for one cycle to cultures of human erythrocytes infected with Plasmodium falciparum prevents the establishment of new infections. Blood parasitemia is eliminated in mice infected with Plasmodium chabaudi adami when they are given a single intraperitoneal injection of Taxol at 150 mg/m2. The majority of the animals treated immediately preceding parasite schizogony remain free of infection after eight replication cycles. The impressive antimalarial activity of Taxol, at a dosage that has been tolerated in humans, establishes its potential utility for treatment of severe, drug-resistant human malaria.