Pharmacokinetics of irinotecan and its metabolites SN-38 and APC in children with recurrent solid tumors after protracted low-dose irinotecan

Irinotecan (IRN), a topoisomerase I interactive agent, has significant antitumor activity in early Phase I studies in children with recurrent solid tumors. However, the disposition of IRN and its metabolites, SN-38 and APC, in children has not been reported. Children with solid tumors refractory to conventional therapy received IRN by a 1-h i.v. infusion at either 20, 24, or 29 mg/m2 daily for 5 consecutive days for 2 weeks. Serial blood samples were collected after doses 1 and 10 of the first course. IRN, SN-38, and APC lactone concentrations were determined by an isocratic high-performance liquid chromatography assay. A linear four-compartment model was fit simultaneously to the IRN, SN-38, and APC plasma concentration versus time data. Systemic clearance rate for IRN was 58.7 +/- 18.8 liters/h/m2 (mean +/- SD). The mean +/- SD ng/ml x h single-day lactone SN-38 area under the concentration-time curve (AUC(0-->6) was 90.9 +/- 96.4, 103.7 +/- 62.4, and 95.3 +/- 63.9 at IRN doses of 20, 24, and 29 mg/m2, respectively. The relative extent of IRN conversion to SN-38 and metabolism to APC measured after dose 1 were 0.49 +/- 0.33 and 0.29 +/- 0.17 (mean +/- SD). No statistically significant intrapatient difference was noted for SN-38 area under the concentration-time curve. Large interpatient variability in IRN and metabolite disposition was observed. The relative extent of conversion and the SN-38 systemic exposure achieved with this protracted schedule of administration were much greater than reported in adults or children receiving larger intermittent doses.

Why does postpsychotic IQ decline in childhood-onset schizophrenia?

OBJECTIVE

The authors' goal was to examine whether the postpsychotic decline in full scale IQ during adolescence for patients with childhood-onset schizophrenia is due to a dementing process or simply failure to acquire new information and skills.

METHOD

Linear regression was used to determine the rate of change for scaled and raw scores on subtests of 31 patients with childhood-onset schizophrenia. The resulting slopes were examined and related to changes in the patients' brains determined by magnetic resonance imaging.

RESULTS

Three postpsychotic subtest scaled scores declined significantly: picture arrangement, information, and block design. In contrast, there was no decline in the non-age-corrected (raw) scores for any subtest. A significant correlation was found between decrease in hippocampal volume and a smaller increase in raw score on the information subtest.

CONCLUSIONS

The decline during adolescence in the full-scale IQ of patients with childhood-onset schizophrenia does not reflect dementia but, rather, an inability to acquire new information and abilities.

Effects of sewage effluent discharge on the abundance, condition and mortality of hulafish, Trachinops taeniatus (Plesiopidae)

The effects of sewage effluent on the abundance, condition (length and reproduction) and mortality of hulafish Trachinops taeniatus were investigated at multiple outfall and control locations on the central coast of New South Wales, Australia. Underwater visual surveys found consistently fewer T. taeniatus at locations where sewage was discharged compared to control locations. The condition of T. taeniatus was investigated by comparing mean length and reproductive indices of fish from two outfall and two control locations. Fish from the largest outfall location were significantly smaller in comparison with fish from control locations. Gravid female fish from outfall locations had similar gonadosomatic indices but a significantly greater number of eggs and smaller size of eggs in comparison with fish from control locations. Mortality of T. taeniatus was investigated during 2-week, in situ, caging experiments at multiple locations and times and 80% of fish survived, although mortalities of up to 73% per cage were recorded at one sewage outfall. T. taeniatus may be a suitable environmental indicator species of sewage pollution.

Williams-Beuren syndrome: an update and review for the primary physician

Williams-Beuren syndrome is an autosomal dominant disorder resulting from a submicroscopic deletion of contiguous genes on the long arm of chromosome 7. It consists of a variety of hallmark physical features, which include distinctive facial characteristics, cardiac anomalies (of which the most common is supravalvular aortic stenosis), and occasional idiopathic hypercalcemia. The condition also includes a unique cognitive profile, with relative sparing of language and facial recognition skills against a background of mental retardation. This paper reviews the early history and clinical experience with this syndrome, how it unfolds from infancy through adulthood, and how it manifests in different organ systems. Evidence-based recommendations are then offered for the treatment of the specific developmental and medical issues that arise in patients with Williams syndrome.

Direct contact between CD34+lin- cells and stroma induces a soluble activity that specifically increases primitive hematopoietic cell production

Perfused human bone marrow (BM) mononuclear cell (MNC) cultures result in a greater long-term culture-initiating cell (LTC-IC) output than parallel CD34+lin- cell cultures, even when CD34+lin- cells are placed on irradiated preformed stroma (IPFS). This difference has been attributed to accessory cell effects that are potentiated by medium perfusion. The present study investigated the relative contributions of direct contact- and soluble-mediated mechanisms of accessory cells in this culture system. CD34+lin- cells within (i.e., in contact with) the MNC accessory cell mixture generated greater LTC-IC output than CD34+lin- cells in contact with IPFS. Incubation of CD34+lin- cells with MNC conditioned medium (CM) resulted in partial restoration of MNC accessory activity, while CM from IPFS had no activity on LTC-IC output. Interestingly, the level of LTC-IC output supported by MNC CM was equivalent to that supported by direct contact with IPFS. CD34+lin- cells were then cultured in Transwell inserts either alone, with IPFS (direct contact), or with IPFS below the insert. Direct contact with IPFS significantly increased the output of cells, CFU-GM, and LTC-IC from CD34+lin- cells. IPFS below the insert also resulted in significantly increased cell and CFU-GM output, but did not significantly affect LTC-IC output. Further experiments using CM from CD34+lin- cells and IPFS cultures showed that LTC-IC supportive activity was present only when direct contact was allowed between CD34+lin- cells and IPFS. ELISA and RT-PCR experiments showed that contact did not induce changes in the levels of several known growth factors, including GM-CSF, IL-1beta, IL-3, IL-6, IL-11, LIF, KL, FL, Tpo, TGF-beta, and MIP-1alpha. These results indicate that direct contact between CD34+lin- cells and IPFS induces soluble activity, which specifically increases LTC-IC output from CD34+lin- cell cultures, providing evidence for a novel direct contact-mediated two-way mechanism of communication between primitive hematopoietic cells and stroma.

Clinical scale expansion of cryopreserved small volume whole bone marrow aspirates produces sufficient cells for clinical use

Ex vivo expansion of bone marrow (BM) mononuclear cells (MNC) in a perfused culture system produces stem-progenitor cell type(s) in sufficient number(s) for hematopoietic reconstitution. The limitations in using fresh BM MNC for ex vivo expansion include additional cell processing and inflexibility in patient treatment. Cryopreservation of whole bone marrow (WBM) eliminates processing costs of MNC or CD34+ cell selection and allows for flexibility in patient treatment. We developed a convenient system to cryopreserve and thaw small volume WBM aspirations (n = 13) and then compared the expandability of unprocessed normal cryopreserved/thawed (C/T) WBM to that of fresh BM MNC cultured in the presence of erythropoietin, PIXY 321, and Flt3-ligand. Ex vivo expansion potential was retained in WBM aspirates after C/T. When initiated with 225 million viable nucleated cells, clinical scale expansion cultures (n = 6) yielded 9.7+/-2.8 x 10(8) total cells, which contained 10.4+/-5.8 x 10(6) colony-forming units-granulocyte-macrophage (CFU-GM), 1.3+/-1.4 x 10(4) LTCIC, and 2.2 x 10(6) CD34+Lin- cells, sufficient cell numbers for clinical use. These studies demonstrate that ex vivo perfusion culture expansion of unfractionated C/T WBM (< or =30 ml) provides doses of stem-progenitor cells similar in composition to expanded fresh BM MNC, previously demonstrated to achieve hematopoietic reconstitution.

Delayed methotrexate clearance in a patient with sickle cell anemia and osteosarcoma

A 15-year-old girl with homozygous sickle cell anemia (HbSS) and osteosarcoma is described. Delayed clearance of methotrexate (MTX) after the second course of high-dose MTX (HDMTX) led to the development of renal and hepatic toxicities. Rescue was accomplished with high-dose leucovorin, intravenous carboxypeptidase G2, and thymidine. Although the renal and hepatic abnormalities resolved, focal tonic-clonic seizures developed, accompanied by abnormal brain imaging. Four weeks after this episode, all clinical and biochemical abnormalities resolved. Preexistent end-organ damage associated with HbSS may compromise the ability to deliver high-dose chemotherapy with curative intent in patients with malignant disease.

Bartenders' respiratory health after establishment of smoke-free bars and taverns

CONTEXT

The association between environmental tobacco smoke (ETS) exposure and respiratory symptoms has not been well established in adults.

OBJECTIVE

To study the respiratory health of bartenders before and after legislative prohibition of smoking in all bars and taverns by the state of California.

DESIGN

Cohort of bartenders interviewed before and after smoking prohibition.

SETTING AND PARTICIPANTS

Bartenders at a random sample of bars and taverns in San Francisco.

MAIN OUTCOME MEASURES

Interviews assessed respiratory symptoms, sensory irritation symptoms, ETS exposure, personal smoking, and recent upper respiratory tract infections. Spirometric assessment included forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) measurements.

RESULTS

Fifty-three of 67 eligible bartenders were interviewed. At baseline, all 53 bartenders reported workplace ETS exposure. After the smoking ban, self-reported ETS exposure at work declined from a median of 28 to 2 hours per week (P<.001). Thirty-nine bartenders (74%) initially reported respiratory symptoms. Of those symptomatic at baseline, 23 (59%) no longer had symptoms at follow-up (P<.001). Forty-one bartenders (77%) initially reported sensory irritation symptoms. At follow-up, 32 (78%) of these subjects had resolution of symptoms (P<.001). After prohibition of workplace smoking, we observed improvement in mean FVC (0.189 L; 95% confidence interval [CI], 0.082-0.296 L; 4.2% change) and, to a lesser extent, mean FEV1 (0.039 L; 95% CI, -0.030 to 0.107 L; 1.2% change). Complete cessation of workplace ETS exposure (compared with continued exposure) was associated with improved mean FVC (0.287 L; 95% CI, 0.088-0.486; 6.8% change) and mean FEV1 (0.142 L; 95% CI, 0.020-0.264 L; 4.5% change), after controlling for personal smoking and recent upper respiratory tract infections.

CONCLUSION

Establishment of smoke-free bars and taverns was associated with a rapid improvement of respiratory health.

Alternatives to animal sera for human bone marrow cell expansion: human serum and serum-free media

The increasing use of cultured human cells in clinical trials is highlighting the need for alternatives to media containing animal sera that are typically used to support these cultures. Perfused cultures of BM mononuclear cells (MNC) were used to evaluate animal sera alternatives with respect to the output of primitive, progenitor, and stromal cells. A serum level of 20% was optimal, and this could be provided by FBS alone or by a mixture of horse serum (HoS) and FBS, but not by HoS alone. Allogeneic human plasma (20%) supported half the level of cell, CFU-GM, and LTC-IC output as compared with animal sera-containing control. Significant donor-to-donor variability in human plasma was observed, but this was mitigated by pooling of plasma samples. Autologous and allogeneic human plasma performed equivalently. The use of autologous or allogeneic human serum was found to be equivalent to the use of human plasma, but all were inferior to animal sera. Animal sera supported typical stroma and cobblestone formation, whereas stroma in human serum cultures was less dense. Eight commercial serum-free media were tested and found to support MNC expansion to varying degrees, but none approached the performance of the animal serum-containing control, particularly with respect to stromal (i.e., CFU-F) support. In fact, when MNC were cultured in parallel with CD34-enriched cells, output (from MNC) was higher only in control medium, apparently because serum-free media reduced accessory cell effects. Because of these results, a new serum-free medium was developed for MNC cultures. This formulation outperformed all commercial serum-free media, resulting in cell and LTC-IC output equivalent to that of control. However, CFU-GM and CFU-F output were 66% and 9% of control, respectively. Precoating the culture surface with collagen increased CFU-F (and Thy-1+ cell) output to control levels, although CFU-GM output was still lower than control. The addition of either fibronectin or PDGF had no measurable effect, nor did the use of 5-100-fold greater concentrations of growth factor supplementation. The serum-free medium also increased CD41+ and CD61+ cell output to 150%-220% of control levels. The development of this new serum-free medium has potential for use in the perfused BM MNC culture systems currently in clinical trials to test the efficacy of expanded cells after cytoablative chemotherapy.

Receptor-mediated folate uptake is positively regulated by disruption of the actin cytoskeleton

Receptor-mediated folate uptake is initiated by binding of ligand to a glycosyl phosphatidylinositol-anchored protein, folate receptor alpha (FR alpha). This receptor is expressed in a limited number of normal tissues but is overexpressed in a large number of epithelial malignancies. FR alpha synthesis, at least in part, is regulated by endogenous folate and by hormones in some cells, but much less is known about the control of function. Recently, we showed that phorbol 12-myristate 13-acetate increases the rate of receptor cycling, increases the rate of folate delivery, and causes the majority of the receptor to reside on the cell surface in nonmalignant cells in vitro (C. M. Lewis et al., Biochim. Biophys. Acta, 1401: 157-169, 1998). However, based upon effects (or lack of effects) of specific inhibitors of protein kinase C, the mechanism of action of phorbol 12-myristate 13-acetate is not likely via protein kinase C. Because exo- and endocytosis are controlled by the actin cytoskeleton, we tested cytochalasin D and latrunculin B, actin-disrupting agents, on FR alpha-mediated folate uptake. Disruption of the actin cytoskeleton reversibly increases the proportion of receptors on the cell surface and increases the rate of 5-methyltetrahydrofolate delivery. Disrupting microtubules with nocodazole had no effect. The increased rate of folate delivery caused by cytochalasin D is not observed in FR-negative cell lines. Although we have not yet identified the upstream effectors, likely candidates include small G-proteins such as rho, which are known to cause actin polymerization. In addition to identifying the machinery for receptor-mediated folate uptake, it may be important to integrate this new data into studies of FR alpha as a tumor antigen for imaging or delivering molecules via anti-FR antibodies or compounds coupled to folic acid.

Ex vivo expansion of bone marrow from breast cancer patients: reduction in tumor cell content through passive purging

High-dose chemotherapy (HDC) with hematopoietic support appears promising in the treatment of breast cancer, although reinfusion of contaminating tumor cells may contribute to disease relapse. Ex vivo expansion may reduce tumor cell content through use of a small inoculum volume and by passive purging during culture. We assessed the ex vivo expansion potential of tumor cell positive bone marrow (BM) from breast cancer patients and the effect of ex vivo expansion on tumor cell content. Cryopreserved/thawed mononuclear cell (C/T MNC) BM harvests with known tumor cell contamination (n = 7) were assessed for tumor cells pre- and post-expansion using immunocytochemical (ICC) staining. Pre-expansion inoculum samples contained a range of 6-2128 tumor cells per 5.0 x 10(6) nucleated cells. Ex vivo expansion resulted in fold expansions of 6.67 and 11.37 for total cells and CFU-GM, respectively. Tumor cells were undetectable in four of the seven post-expansion samples and were reduced in the remaining three samples. The data demonstrate passive purging of breast cancer cells during ex vivo expansion, with hematopoietic progenitor cell expansion comparable to that of normal BM. Reduction in tumor cell number contained in the small volume culture inoculum combined with passive purging during the ex vivo expansion process suggest a potential 2-4+ log reduction in tumor cell content in the reinfused cell product.

Quantitative long-term culture-initiating cell assays require accessory cell depletion that can be achieved by CD34-enrichment or 5-fluorouracil exposure

Characterization of hematopoietic cells and measurement of their proliferative potential is critical in many research and clinical applications. Because in vivo assay of human cells is not possible and xenogeneic assays are not yet routine, in vitro assays such as the long-term culture-initiating cell (LTC-IC) assay have been widely adopted. This study investigated LTC-IC assay linearity and reproducibility and resulting implications with respect to quantitation of primitive cell expansion. Measurement of secondary colony-forming cells (2 degrees CFCs) from 5-week cultures of bone marrow (BM) mononuclear cells (MNCs) showed that 2 degrees CFC frequency varied with assay plating density in a nonlinear fashion. The measured 2 degrees CFC frequency increased from 4.6 to 63.8 (per 10(5) MNCs) as assay plating density was decreased from 5 x 10(5) to 2 x 10(4) MNCs per well (P < 10(-6), n = 37). In contrast, assay of CD34-enriched cells was linear within the range studied. Assays of cells obtained from expansion cultures initiated with either MNCs or CD34-enriched cells were also nonlinear. Consequently, calculated 2 degrees CFC expansion ratios were ambiguous and dependent on the assay plating densities used. Limiting dilution analysis (LDA) results were also nonlinear, with LTC-IC frequency increasing from 8. 2 to 22.4 per 10(5) MNCs (P < 10(-4), n = 100) as assay plating densities were decreased. Despite the nonlinearity, 2 degrees CFC and LTC-IC assay results were consistent and reproducible over time with different samples and techniques and gave a semiquantitative indication of relative primitive cell frequency. Although CD34-enriched cells gave linear assay output, purification of cells for every assay is impractical. Therefore, exposure of cells to 5-fluorouracil (5-FU) was explored for improving assay linearity. Incubation of MNCs in 250 microg/mL 5-FU for 1 to 2 hours depleted accessory cells and resulted in a cell population that gave linear 2 degrees CFC readout. The 5-FU-resistant LTC-ICs accounted for 49% of the total LTC-IC population, adding the potential benefit of restricting assay measurement to more primitive noncycling LTC-ICs. Consequently, similar linear assay results can be obtained with either the bulk 2 degrees CFC or LDA LTC-IC methods after 5-FU, but multiple plating densities are nevertheless still required in both methods due to the greater than 100-fold range in primitive cell frequency present in normal human donor BM.

Childhood-onset schizophrenia: an open-label study of olanzapine in adolescents

OBJECTIVE

Olanzapine, a potent 5-HT2a/2c, dopamine D1D2D4 antagonist with anticholinergic activity, has a profile of known receptor affinity similar to that of clozapine. This pilot study examined the efficacy of olanzapine for treatment-refractory childhood-onset schizophrenia in eight patients who had received 8-week open-label trials. For comparison, data are included from 15 patients who had received 6-week open-label clozapine trials using identical rating instruments (largely by the same raters) in the same treatment setting.

METHOD

Twenty-three children and adolescents with an onset of DSM-III-R schizophrenia by age 12 for whom at least two different typical neuroleptics had been ineffective participated in the two separate studies. Some of the patients were intolerant of clozapine, although it had been effective (n = 4). Patients receiving olanzapine were evaluated over 8 weeks with the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Positive Symptoms, the Scale for the Assessment of Negative Symptoms, and the Clinical Global Impressions Scale for Improvement.

RESULTS

For the eight patients who received olanzapine trials, at week 8 there was a 17% improvement in the BPRS total score, a 27% improvement in the Scale for the Assessment of Negative Symptoms, and a 1% improvement in the Scale for the Assessment of Positive Symptoms, relative to "ideal" admission status on typical neuroleptics. In contrast, the magnitude of the effect sizes for each of the clinical ratings was larger at week 6 of the previous clozapine trial than for an 8-week olanzapine trial, relative to admission status on typical neuroleptics. For the four children who had received both clozapine and olanzapine, BPRS total scores were significantly lower at week 6 of clozapine treatment compared with week 6 of olanzapine treatment (p = .03).

CONCLUSION

These data provide preliminary evidence for the efficacy of olanzapine for some children and adolescents with treatment-refractory schizophrenia, but they also suggest the need for a more rigorous double-blind comparison of these two atypical antipsychotics.

Clinical-scale human umbilical cord blood cell expansion in a novel automated perfusion culture system

Use of umbilical cord blood (CB) for stem cell transplantation has a number of advantages, but a major disadvantage is the relatively low cell number available. Ex vivo cell expansion has been proposed to overcome this limitation, and this study therefore evaluated the use of perfusion culture systems for CB cell expansion. CB was cryopreserved using standard methods and the thawed unpurified cells were used to initiate small-scale cultures supplemented with PIXY321,flt-3 ligand, and erythropoietin in serum-containing medium. Twelve days of culture resulted in the optimal output from most CB samples. Frequent medium exchange led to significant increases in cell (93%), CFU-GM (82%) and LTC-IC (350%) output as compared with unfed cultures. As the inoculum density was increased from 7.5 x 10(4) per cm2 to 6.0 x 10(5) per cm2, the output of cells, CFU-GM, and LTC-IC increased. Cell and CFU-GM output reached a plateau at 6.0 x 10(5) per cm2, whereas LTC-IC output continued to increase up to 1.2 x 10(6) per cm2. Because the increase in culture output did not increase linearly with increasing inoculum density, expansion ratios were greatest at 1.5 x 10(5) per cm2 for cells (6.4-fold) and CFU-GM (192-fold). Despite the lack of adherent stroma, CB cultures expressed mRNA for many growth factors (G-CSF, GM-CSF, IL-1, IL-6, LIF, KL, FL, Tpo, TGF-beta, TNF-alpha, and MIP-1alpha) that were also found in bone marrow (BM) cultures, with the exception of IL-11 (found only in BM) and IL-3 (found in neither). Culture output was remarkably consistent from 10 CB samples (coefficient of variation 0.3) indicating that the procedure is robust and reproducible. Two commercial serum-free media were evaluated and found to support only approximately 25% of the culture output as compared with serum-containing medium. Implementation of optimal conditions in the clinical scale, automated cell production system (CPS) showed that the process scaled-up well, generating 1.7 x 10(7) CFU-GM (298-fold expansion) from 1.2 x 10(8) thawed viable nucleated CB cells (n = 3). The ability to generate >10(7) CFU-GM from <15 ml of CB within this closed, automated system without the need for extensive cell manipulations will enable clinical studies to test the safety and efficacy of expanded CB cells in the transplant setting.

PMA alters folate receptor distribution in the plasma membrane and increases the rate of 5-methyltetrahydrofolate delivery in mature MA104 cells

MA104 cells (a monkey kidney cell line) can internalize 5-methyltetrahydrofolate via a receptor mediated process termed potocytosis. Uptake is initiated by binding to an external folate receptor which cycles to an internal, but membrane bound compartment. These two pools can be measured by determining the amount of [3H]ligand removed by an acid-saline wash, i.e. acid labile and acid resistant pools. When assayed in confluent nonmitotic cells, 2/3 of the folate receptor pool is located in an internal (acid resistant) compartment, but phorbol 12-myristate 13-acetate (PMA) causes a shift such that 65-75% of the receptor pool resides on the surface of the plasma membrane. This new steady state is likely the result of an increased rate of receptor movement. In addition, PMA increases the rate of 5-methyl[3H]tetrahydrofolate delivery to the cytoplasm 1.8 fold. Using known inhibitors of potocytosis, we were able to show that the increased rate of delivery is receptor mediated. Comparison of the time courses of the PMA effects on folate receptor redistribution assessed by membrane binding of [3H]folic acid and 5-methyl[3H]tetrahydrofolate delivery to the cytoplasm suggests that PMA may be activating more than one protein kinase C independent signal transduction pathway. PMA is the first reported positive modulator of receptor mediated folate uptake.

Evidence for negative feedback of extracellular methotrexate on blasts of acute lymphoblastic leukemia in vitro

STUDY OBJECTIVE

To explore the value of high-dose methotrexate (MTX).

SUBJECTS

Blast cells from 15 patients with acute lymphoblastic leukemia.

INTERVENTIONS

We compared uptake and polyglutamation of [3H]-MTX by freshly isolated leukemic blasts in vitro after 24-hour exposure to 1, 10, and 50 microM [3H]-MTX.

MEASUREMENTS AND MAIN RESULTS

Mean MTX uptake (pmol/10(6) cells) was 0.78 +/- 0.19, 2.3 +/- 0.54, and 5.9 +/- 1.9, respectively, and mean polyglutamation was 82%, 66%, and 46%. Consequently, mean MTX polyglutamates were 0.68 +/- 0.18, 1.5 +/- 0.47, and 2.2 +/- 0.67 pmol/10(6) cells. Three of 15 patient samples had no detectable polyglutamation of MTX at 50 microM but MTX polyglutamates were detectable at 1 microM. Two of these three had a decrease in MTX polyglutamates at 10 versus 1 microM. In eight precursor B cell samples there was a significant difference in median MTX polyglutamates at 1 versus 10 microM but not 10 versus 50 microM.

CONCLUSION

Increasing extracellular MTX concentrations may be counterproductive for some patients with acute lymphoblastic leukemia. If MTX polyglutamates are important for efficacy, optimal delivery of MTX may have to be determined by individual metabolism rather than by targeting a specific drug concentration.

Structure of benzyl T-antigen disaccharide bound to Amaranthus caudatus agglutinin

Amaranthus caudatus agglutinin contains a novel arrangement of four beta-trefoil domains. The sugar-binding site provides specificity for the carcinoma-associated T-antigen disaccharide even when 'masked' by other sugars.

Effect of frequency of follicle aspiration on oocyte yield and subsequent superovulatory response in cattle

The effect of frequency of transvaginal follicular aspiration on oocyte yield and subsequent superovulatory response was studied in 2 experiments. In Experiment 1, 32 primiparous Hereford x Friesian cows were assigned to 4 treatments (n = 8 per treatment). Oocyte recovery was carried out once a week for 12, 8, 4 or 0 (control) wk. Embryo recovery for all animals was 7 wk after the completion of the aspiration schedules. In Experiment 2, the effects of oocyte recovery once or twice a week (n = 8 per treatment; control n = 18) for 12 wk and response to superovulation 4 wk after the last aspiration were compared using nulliparous purebred Simmental heifers. Increasing the period of once weekly aspirations from 4 to 12 wk (Experiment 1) did not affect the number of follicles observed per session (mean +/- SEM; 10.0 +/- 0.82) or aspirated (7.8 +/- 0.71), but the recovery rate of oocytes from follicles aspirated was greater for donors aspirated for either 4 or 8 wk than for 12 wk (32.3 +/- 3.73 vs 28.4 +/- 2.61 vs 20.1 +/- 2.13 %; P < 0.05). Following the last aspiration and prior to commencing superovulatory procedures, estrus or estrous activity was observed in 7 8 , 8 8 , 7 8 and 6 8 of the animals aspirated over 12, 8, 4 or 0 wk, respectively. Subsequent superovulatory responses and in vivo embryo recoveries were similar for all aspiration treatments and for control animals. Changing the frequency of oocyte recovery from once to twice weekly (Experiment 2) did not affect the numbers of follicles observed (9.1 +/- 0.63 vs 8.3 +/- 0.85), follicles aspirated (5.9 +/- 0.56 vs 6.2 +/- 0.69), oocytes recovered (1.7 +/- 0.27 vs 1.9 +/- 2.0) per session or the oocyte recovery rate (29.4 +/- 2.4 vs 30.4 +/- 2.4 %); nor was there any effect of frequency of aspiration on subsequent superovulatory response and embryo recovery. In conclusion, increasing the period of aspiration from 4 to 12 wk and the frequency from once to twice a week over 12 wk did not reduce the number of follicles observed or aspirated, or number of oocytes recovered per donor per session. Subsequent estrous cyclicity and responses to superovulation were unaffected by the periods or frequencies of oocyte recovery examined here.

Childhood-onset schizophrenia. A double-blind clozapine-haloperidol comparison

BACKGROUND

Childhood-onset schizophrenia is a rare but severe form of the disorder that is often treatment-refractory. In this study, the efficacy and adverse effects of clozapine and haloperidol were compared for children and adolescents with early-onset schizophrenia.

METHODS

Twenty-one patients (mean [+/-SD] age, 14.0 +/- 2.3 years) with onset of Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition-defined schizophrenia that began by age 12 years and who had been nonresponsive to typical neuroleptics participated in the study. Patients were randomized to a 6-week double-blind parallel comparison of clozapine (mean [+/-SD] final dose, 176 +/- 149 mg/d), or haloperidol, (16 +/- 8 mg/d).

RESULTS

Clozapine was superior to haloperidol on all measures of psychosis (P = .04-.002). Positive and negative symptoms of schizophrenia improved. However, neutropenia and seizures were major concerns. To date, one third of the group has discontinued using clozapine.

CONCLUSIONS

Clozapine has striking superiority for positive and negative symptoms in treatment-refractory childhood-onset schizophrenia. However, due to possibly increased toxic effects in this pediatric population, close monitoring for adverse events is essential.

Norgestomet implants, plasma progesterone concentrations and embryo transfer pregnancy rates in cattle

A study was undertaken to test the hypothesis that supplementation with exogenous progestagen at the time of embryo transfer would enhance pregnancy rates in recipients. Two-hundred-and-seventy-two oestrus-synchronised crossbred heifer and cow recipients received 200 grade 1 and 72 grade 2 Simmental embryos transferred non-surgically. Heparinised blood samples were taken on day 6 and day 7 (oestrus = day 0) for the assessment of the endogenous plasma progesterone concentration. Half the recipients received an ear implant impregnated with 3 mg norgestomet on the day of embryo transfer. The pregnancy rates were 51.9 and 49.6 per cent for the norgestomet-treated and control groups, respectively. The pregnancy rate for grade 1 embryos was 56.0 per cent and for grade 2 embryos 36.1 per cent (P < 0.01). The breed of recipient, weekday of transfer, operator and condition score had no effect on pregnancy rate. The maiden heifers had a higher pregnancy rate (54.2 per cent) than the cows (46.2 per cent). The mean plasma progesterone concentrations of the pregnant and non-pregnant groups on day 6 were 6.7 ng/ml and 6.6 ng/ml, respectively, and 7.6 ng/ml in both groups on day 7.

Detection of non-steroidal anti-inflammatory drugs in equine plasma and urine by gas chromatography-mass spectrometry

A gas chromatographic-mass spectrometric (GC-MS) procedure for the detection of seventeen non-steroidal anti-inflammatory drugs (NSAIDs) in equine plasma and urine samples is described. The extraction of the compounds from the biological matrix was performed at acidic pH (2-3) with diethyl ether. Ethereal extracts were washed with a saturated solution of sodium hydrogencarbonate (urine) or treated with a solid mixture of sodium carbonate and sodium hydrogencarbonate (plasma). The ethereal extracts were dried and derivatized by incubation at 60 degrees C with methyl iodide in acetone in the presence of solid potassium carbonate. Mono- or bismethyl derivatives of the NSAIDs were obtained. After derivatization kinetic studies, 90 min was the incubation time finally chosen for screening purposes for adequate methylation of all the compounds under study. For individual confirmation analyses, shorter incubation times can be used. The chromatographic analysis of the derivatives was accomplished by GC-MS with a run time of 13 min. In general, extraction recoveries ranged from 23.3 to 100% in plasma and from 37.5 to 83.8% in urine samples. Detection limits from less than 5 to 25 ng/ml were obtained for both plasma and urine samples using selected-ion monitoring. The procedure was applied to the screening and confirmation of NSAIDs in routine doping control of equine samples.

Evaluation of magnetic alginate beads as a solid support for positive selection of CD34+ cells

Paramagnetic alginate beads with a 10-100 microns size range have been developed. These beads, when activated with chloroacetic anhydride and covalently coupled to avidin (30 micrograms/mg beads), were able to bind biotinylated goat anti-mouse (B-GAM) antibody (Ab). The beads with immobilized antibody were then used as a model system for the capture and non-enzymatic release of CD34+ (KG1a) cells. A maximum of 82% KG1a (average = 65 +/- 16.1%) cell capture, and 57% (average = 51 +/- 5.9%) cell release has been attained using this model system. Optimization of the system in terms of further bead size reduction, and in terms of developing a system to recover released cells with high purity, will make an excellent system for cell capture and nonenzymatic release.

Accumulation of 5-methyltetrahydrofolic acid and folylpolyglutamate synthetase expression by mitogen stimulated human lymphocytes

The accumulation of 5-methyl[3H]tetrahydrofolic acid (5CH3[3H]FH4) by phytohaemagglutinin stimulated lymphocytes (PHA-L) cultured in folate free media was investigated to determine the mechanism of uptake of 5CH3FH4 and the requirement of the cells for this vitamin as assessed by monitoring de novo thymidine synthesis. When grown in 20 nM 5CH3[3H]FH4 PHA-L accumulate radiolabel at a rate of 0.04 pmol/h/10(6) cells. This doubles the endogenous folate pool of unstimulated cells (0.6 +/- 0.16 pmol/10(6) cells) in about 15 h. Uptake proceeded via a saturable process, independent of a high affinity folate receptor as assessed by ligand binding and by Northern and Western blot analysis. However, transport was blocked by probenecid, which is consistent with an anion carrier mechanism. Unstimulated cells lacked folypolyglutamate synthetase (FPGS) activity and did not express significant amounts of FPGS mRNA. After 48 h of mitogen stimulation there was a 4-10-fold increase in FPGS mRNA and folypolyglutamate formation (Glu > or = 5) was essentially simultaneous with 5CH3[3H]FH4 transport. Increasing extracellular folate to 2 microM only increased intracellular folate 8-fold, but the length of the folylpolyglutamates decreased. The increased folate did not increase de novo thymidine synthesis compared to cells grown in physiological folate. We conclude that mitogen stimulation activates the process(es) for folate accumulation, especially FPGS, and that physiological uptake (0.04 pmol/h/10(6) cells) is adequate for meeting the cells' need for the vitamin.

5,10-Dideazatetrahydrofolic acid (DDATHF) transport in CCRF-CEM and MA104 cell lines

5,10-Dideazatetrahydrolic acid (DDATHF) is representative of a new class of antifolates acting through inhibition of de novo purine synthesis. We report here the transport characteristics of the diastereomers of DDATHF, which differ in configuration at C6, and comparison studies with other folate and antifolate analogs. (6R)-DDATHF showed high affinity for the influx system of CCRF-CEM cells with a Km of 1.07 microM and an influx Vmax of 4.04 pmol/min/10(7) cells. Comparative studies with methotrexate yielded an influx Km of 4.98 microM and a Vmax of 6.64 pmol/min/10(7) cells, and with 5-formyltetrahydrofolate an influx Km of 2.18 microM and a Vmax of 6.84 pmol/min/10(7) cells. Uptake of (6R)-DDATHF was competitively inhibited by (6S)-DDATHF, methotrexate (MTX), and 5-formyltetrahydrofolate, all with Ki values similar to their influx Km. The (6S)-DDATHF diastereomer had an influx Km of 1.04 microM, similar to that of (6R)-DDATHF; however, the Vmax of 1.72 pmol/min/10(7) cells was 2.3-fold lower than for (6R)-DDATHF. The transport properties of DDATHF were also studied in a mutant cell line (CEM/MTX), resistant to MTX based on impaired drug transport. In this system (6R)-DDATHF showed an influx Km of 1.49 microM and a decreased influx Vmax of 0.60 pmol/min/10(7) cells. A similar effect was shown for MTX (Km of 7.48 microM, Vmax of 1.02 pmol/min/10(7) cells). The number of binding sites in CCRF-CEM cells was similar for (6R)-DDATHF, (6S)-DDATHF, and MTX, 0.74, 0.71, and 0.76 pmol/10(7) cells, respectively. These values were slightly higher in the CEM/MTX cell line (1.07 and 1.09 pmol/10(7) cells for (6R)-DDATHF and MTX, respectively). Treatment of CCRF-CEM cells with either the N-hydroxysuccinimide ester of MTX or the corresponding N-hydroxysuccinimide ester of (6R)-DDATHF caused substantial inhibition (> 90%) of the influx of (6R)-[3H]DDATHF and [3H]MTX, respectively. These results suggest strongly that DDATHF and MTX share a common influx mechanism through the reduced folate transport system. The internalization of DDATHF by monkey kidney epithelial MA104 cells, which express a high affinity folate receptor, was also studied. Competitive binding studies using purified folate receptor and radiolabeled 5-methyltetrahydrofolate showed that (6S)- and (6R)-DDATHF both had I50 values lower than 5-methyltetrahydrofolate (12 nM). Further studies indicate that both DDATHF isomers are actively intracellularly concentrated through this route and are also rapidly converted to high chain length polyglutamates. Transport via this system was inhibited in folate-depleted cells by 10 nM folic acid.(ABSTRACT TRUNCATED AT 400 WORDS)

The folate receptor works in tandem with a probenecid-sensitive carrier in MA104 cells in vitro

Previous studies have defined a novel route of internalization for the essential vitamin 5-methyltetrahydrofolate in MA104 cells that begins with binding of the vitamin to the membrane receptor for folate. One of the critical steps in the pathway is the passage of 5-methyltetrahydrofolate through the membrane into the cytoplasm. Utilizing both probenecid and low temperature as selective inhibitors, we have successfully blocked transmembrane movement of the vitamin into the cytoplasm without affecting binding to the receptor or the internalization of the vitamin-receptor complex, which suggests that passage is through an anion carrier. This anion carrier, which mediates inward movement of 5-methyltetrahydrofolate after it dissociates from the receptor, also appears to mediate the efflux of folylmonoglutamate, but not folylpolyglutamate, when the concentration of the former in the cytoplasm is sufficiently high. Since we also found that the synthesis of folylpolyglutamates is regulated in these cells, most likely the intracellular concentration of the vitamin is controlled by regulating the flux of folylmonoglutamate through this carrier.

Characterization of binding of simian rotavirus SA-11 to cultured epithelial cells

Rotavirus causes enteritis in both man and animals. The identity of the rotavirus receptor is not known. The nature of the binding interaction and the relationship between virus binding and internalization have not previously been reported. We studied the binding of [5,6-3H]uridine-labeled rotavirus SA11 to confluent monolayers of MA104 cells. We found approximately 13,000 receptor units per cell. The binding was sodium-dependent, pH-insensitive between 5.5 and 8, independent of added calcium, and dependent on sialic acid residues in the membrane. It could be inhibited by mucin. These features may provide clues to the identity of the receptor. Virus was not internalized to significant extent at 4 degrees C. After warming to 37 degrees C, virus was internalized over about 60 min. All binding sites appeared to be equally internalizable. The techniques developed to distinguish between binding and internalization may help to elucidate the mechanism of internalization.

Effect of dietary supplementation with n-3 fatty acids on clinical manifestations of psoriasis

In a double-blind, block randomized study we investigated the effect of dietary supplementation with eicosapentaenoic acid in patients with psoriasis. The experimental group received 10 g of fish oil daily containing approximately 1.8 g eicosapentaenoic acid, while the controls were given an isoenergetic amount of olive oil. We found no significant change in the clinical manifestations of psoriasis in either group after 8 weeks of treatment. In the experimental group, the amount of n-3 fatty acids in serum phospholipids was significantly increased at the end of trial as compared to pre-treatment values, whereas the level of n-6 fatty acids was decreased.

A novel iron protein from Desulfovibrio gigas

The isolation, purification, and partial characterization of a novel iron-containing protein from the sulfate-reducing anaerobic bacterium, Desulfovibrio gigas, is described. The highly insoluble protein was isolated from the cell debris following osmotic shock of the bacteria. The insoluble fraction consistently contained about 90% of the cell-associated iron. Elemental analysis of a crude protein preparation gave 5.3% iron, 2.9% sulfur and 11.9% nitrogen. An independent colorimetric iron analysis showed 6.4% iron. The iron could be dissociated from the protein by treatment with 5% SDS. The iron-free protein was purified by a combination of organic extraction and DEAE-cellulose chromatography. The purified protein showed only one major band, Mr 14000, by SDS-polyacrylamide gel electrophoresis. The protein could be reconstituted upon treatment with an appropriate mixture of FeS and beta-mercaptoethanol. The reconstituted protein had the same physical and chemical properties as the native protein. The amino acid composition was not unusual except for the high isoleucine content.

Total Yield Measurements in 31P(p, g)32S

The reaction 31p(p, )I)32S has been investigated in the proton energy range 0�33-1�75 MeV. Total )I-ray strengths were determined for 28 resonances. Yield curves were measured over limited portions of the energy range, which between them covered the whole range. An estimate of the nonresonant cross section was obtained, and total resonance widths were deduced.

Total Yield Measurements in 23Na(p, g)24Mg

The reaction 23Na(p, y)24Mghas been investigated in the proton energy range 0'25-2�5 MeV. Total "..ray strengths were determined for 64 resonances. A yield curve was measured over the range 0�65-2�55 MeV, and an estimate of the nonresonant cross section was obtained. Total resonance widths were deduced for 32 levels.

HEALTH HAZARDS OF THE DYE INDUSTRY

The first step in prevention of poisoning in the dye industry includes well-ventilated, properly equipped buildings. Selection of workmen is important and the use of the best methods in manufacturing. These investigations, which are based on 2,500 employees, whose blood was tested periodically, yield some minor diagnostic material.