Survey estimates of fishable biomass following a mass mortality in an Australian molluscan fishery

Mass mortality events are relatively uncommon in commercially fished populations, but when they occur, they reduce production and degrade ecosystems. Observing and documenting mass mortalities is simpler than quantifying the impact on stocks, monitoring or predicting recovery, and re-establishing commercial fishing. Direct survey measures of abundance, distribution and harvestable biomass provide the most tenable approach to informing decisions about future harvests in cases where stock collapses have occurred because conventional methods have been disrupted and are less applicable. Abalone viral ganglioneuritis (AVG) has resulted in high levels of mortality across all length classes of blacklip abalone, Haliotis rubra Leach, off western Victoria, Australia, since May 2006. Commercial catches in this previously valuable fishery were reduced substantially. This paper describes the integration of research surveys with commercial fishermen's knowledge to estimate the biomass of abalone on AVG-impacted reefs. Experienced commercial abalone divers provided credible information on the precise locations of historical fishing grounds within which fishery-independent surveys were undertaken. Abalone density estimates remained low relative to pre-AVG levels, and total biomass estimates were similar to historical annual catch levels, indicating that the abalone populations have yet to adequately recover. Survey biomass estimates were incorporated into harvest decision tables and used with prior accumulated knowledge of the populations to determine a conservative harvest strategy for the fishery.

Dendritic cell-based treatment of cancer: closing in on a cellular therapy

PURPOSE

Dendritic cells are the most potent antigen-presenting cells and are critical to initiation of immune responses. Dendritic cells loaded ex vivo with tumor-associated antigen are being administered to cancer patients in an effort to jump-start a potent, cell-mediated anticancer immune response resulting in tumor shrinkage and clinical benefit.

PATIENTS AND METHODS

Dendreon Corporation has designed three therapeutic vaccines using blood-derived dendritic cells loaded ex vivo with antigen: Provenge for prostate cancer; Mylovenge for multiple myeloma and other B-cell malignancies; and APC8024 for cancers expressing the HER-2/neu proto-oncogene.

RESULTS

Preclinical studies demonstrated that blood dendritic cells matured spontaneously in short-term culture without growth factors, and that fusion of antigens with granulocyte-macrophage colony-stimulating factor enhances antigen uptake and presentation by blood dendritic cells. Phase I/II trials suggest that these dendritic cell-based vaccines are safe and well tolerated. Provenge has demonstrated antitumor activity in hormone-refractory prostate cancer; approximately 20% of patients experienced decreased prostate-specific antigen (i.e., PSA) levels and a similar percentage experienced disease stabilization. Double-blind, placebo-controlled, randomized trials in metastatic, asymptomatic hormone-refractory prostate cancer have been initiated. Phase II data on Mylovenge are similarly encouraging, and expanded phase II testing is ongoing in anticipation of opening phase III trials in 2002. APC8024 is in early clinical development and has shown significant capacity to elicit antigen-specific immune responses.

CONCLUSION

Antigen delivery by ex vivo antigen-loaded dendritic cells may be an effective approach to cancer immunotherapy.

Phase I trial of sequential administration of raltitrexed (Tomudex) and 5-iodo-2'-deoxyuridine (IdUrd)

Raltitrexed (Tomudex) is a specific inhibitor of thymidylate synthase with clinical activity in colorectal cancer. The combination of raltitrexed and 5-iodo-2'-deoxyuridine (IdUrd, a cytotoxic pyrimidine analog) resulted in increased IdUrd incorporation into DNA and exhibited in vitro synergism against colon and bladder human carcinoma cell lines. We designed a phase I trial to determine the MTD, pharmacokinetics, and biologic effects of escalating doses of the combination of IdUrd given as a 24-hour infusion after a raltitrexed 15-minute infusion every three weeks. Thirty-four patients received 95 courses of raltitrexed and IdUrd at doses ranging from raltitrexed 1 mg/m2 and IdUrd 750 mg/m2 to raltitrexed 2.5 mg/m2 and IdUrd 10,400 mg/m2. The median number of cycles administered was 2 (range 1-10). Dose limiting hematologic toxicity occurred at doses of raltitrexed 2.5 mg/m2 and IdUrd 10,400 mg/m2. In addition, we determined the mean plasma concentrations C(SS) of IdUrd, the iodouracil level at 22 hours and the IdUrd clearance. Raltitrexed did not appear to affect the pharmacokinetics of IdUrd in the dose range tested. The recommended phase II dose is raltitrexed 2 mg/m2 and IdUrd 10,400 mg/m2 repeated every three weeks. Evidence of potential antitumor activity was observed: 1 patient (with colon cancer) had a partial response while 15 others had stable disease.

Identification of inhibitors of heparin–growth factor interactions from combinatorial libraries of four-component condensation reactions

Chemical libraries based on four-component condensation (4CC) reactions of isocyanides were constructed to identify compounds capable of blocking heparin binding to vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). The reaction products in the synthesized libraries contain heparin mimetic functional groups such as carbohydrates, sulfonates, carboxylates, and hydroxy groups. These libraries have been screened for the inhibition of heparin binding to growth factors such as VEGF and bFGF. Single point screening at 5.0 microM of the 18,720 reaction products generated 26 candidates. The IC50S of these 26 compounds were determined using HPLC-purified products and 20 of the 26 showed significant inhibition of heparin binding to VEGF and/or bFGF. Eighteen of the 20 confirmed active compounds have a linear extended structure. Structures identified in this library revealed an initial relationship of structure and activity, thus providing direction for further investigation of this type of heparin mimetic libraries.

Molecular cloning, expression analysis, and chromosome mapping of WDR6, a novel human WD-repeat gene

The WD-repeat proteins are found in all eukaryotes and play an important role in the regulation of a wide variety of cellular functions such as signal transduction, transcription, and proliferation. Here we report on the cloning and characterization of a novel human WD-repeat gene, WDR6, which encodes a protein of 1121 amino acids and contains 11 WD-repeat units. WDR6 is unique since its 11 WD repeats are clustered into two distinct groups separated by a putative transmembrane domain. The WDR6 gene was mapped to chromosome 15q21 by fluorescence in situ hybridization. Northern analysis demonstrated that WDR6 is ubiquitously expressed in human adult and fetal tissues. WDR6 is not homologous to any previously identified human WD-repeat genes including WDR1 through WDR5. However, it was found to have significant sequence similarity with Arabidopsis thaliana hypothetical protein T7B11.12, yeast putative elongation factor G, and probable membrane protein YPL183c. All of them have been defined as WD-repeat proteins. Therefore, WDR6 is a novel protein and probably belongs to a highly conserved subfamily of WD-repeat proteins in which T7B11.12 and YPL183c are its distantly related members.

Immunotherapy of advanced malignancy by direct gene transfer of an interleukin-2 DNA/DMRIE/DOPE lipid complex: phase I/II experience

PURPOSE

We have completed a phase I study, followed by three phase I/II studies, in patients with metastatic melanoma, renal cell carcinoma (RCC), and sarcoma in order to evaluate the safety, toxicity, and antitumor activity of Leuvectin (Vical Inc, San Diego, CA), a gene transfer product containing a plasmid encoding human interleukin (IL)-2 formulated with the cationic lipid 1, 2-dimyristyloxypropyl-3-dimethyl-hydroxyethyl ammonium bromide/dioleyl-phosphatidyl-ethanolamine (DMRIE/DOPE) and administered intratumorally.

PATIENTS AND METHODS

Twenty-four patients were treated in the phase I study. Leuvectin doses were 10 microg, 30 microg, or 300 microg weekly for 6 weeks. In three subsequent phase I/II studies, a total of 52 patients (18 with melanoma, 17 with RCC, and 17 with sarcoma) were treated with further escalating doses of Leuvectin: 300 microg twice a week for 3 weeks, 750 microg weekly for 6 weeks, and 1,500 microg weekly for 6 weeks.

RESULTS

There were no drug-related grade 4 toxicities and only one grade 3 toxicity, but the majority of patients experienced mild constitutional symptoms after treatment. In the phase I/II studies, 45 patients were assessable for response (14 with RCC, 16 with melanoma, and 15 with sarcoma). Two patients with RCC and one with melanoma have achieved partial responses lasting from 16 to 19 months and continuing. In addition, two RCC, three melanoma, and six sarcoma patients had stable disease lasting from 3 to 18 months and continuing. The plasmid was detected by polymerase chain reaction assay in the posttreatment samples of 29 of 46 evaluated patients. Immunohistochemistry studies on serial biopsy specimens showed increased IL-2 expression and CD8(+) infiltration after treatment in the tumor samples of several patients (12 and 16, respectively).

CONCLUSION

Direct intratumoral injection of Leuvectin is a safe and possibly effective immunotherapeutic approach in the treatment of certain tumor types.

Aerosol granulocyte macrophage-colony stimulating factor: a low toxicity, lung-specific biological therapy in patients with lung metastases

The objective was to study the feasibility of granulocyte macrophage-colony stimulating factor (GM-CSF) delivery to the lung using an aerosol in humans. A Phase I dose escalation study provided GM-CSF at three dose levels as a twice-a-day (BID) x 7 days schedule. Pulmonary functions were monitored using a remote spirometry device. Blood counts were checked at the beginning and end of each week of GM-CSF nebulization. If no toxicity was encountered, patients rested for 7 days and then were treated at the next dose level. Six of seven patients were successfully dose escalated from 60 microg/dose BID x 7 days, to 120 microg/dose BID x 7 days, then 240 microg/dose BID x 7 days. No toxicity was seen. Comparison of day 0 and day 7 blood leukocyte counts showed no significant increases in either leukocyte numbers or percentage of neutrophils. Pulmonary functions test changes were minor. No significant change in forced vital capacity, FEV1, peak flow, or FEF 25-75 related to either time or dose level was observed. One patient's lung metastases progressed. The other five patients received an additional 2-6 months of intermittent aerosol GM-CSF at dose level 3 without side effects. One patient with Ewing's sarcoma has a complete response, and a patient with melanoma had a partial response; the other three had stabilization of pulmonary metastases for 2-6 months. Aerosol delivery of GM-CSF is feasible, safe, and possibly effective. Aerosol cytokine delivery may achieve effective immunological activation against cancer in the lung and is worthy of further study.

Future role of radiotherapy as a component of treatment in biliopancreatic cancers

For resected and unresectable pancreas cancers, data will be summarized from both adjuvant and locally unresectable pancreas cancer series (EBRT +/- IOERT) to demonstrate the justification of continuing to utilize chemo-irradiation as a component of treatment. The resultant improvements in local control with combined modality treatment, however, achieve only minimal improvements in survival in view of the high incidence of abdominal relapse (liver and peritoneal). Further improvement in survival may necessitate regional approaches for chemotherapy or may await advances in gene therapy. For locally unresectable and resected but residual bile duct malignancies, chemoirradiation appears to enhance tumor control and survival. Dose intensification of both modalities may be useful in improving disease control and survival. After chemoirradiation, the addition of liver transplant, in carefully selected patients who are unresectable with standard resection, may further enhance disease control and survival over what would be expected with either approach in isolation.

Characterization of Mycobacterium paratuberculosis p36 antigen and its seroreactivities in Crohn's disease

Recent data using improved cultural, molecular, and serological techniques have strengthened the association of Mycobacterium paratuberculosis with Crohn's disease, an inflammatory bowel disease (IBD) with unknown etiology. To provide more evidence of an etiological association, antibody reactivities of Crohn's disease patients were tested by immunoblotting against M. paratuberculosis-recombinant antigens. A clone containing a 1,402-bp insert and expressing a 36K-antigen (p36) was analyzed. No homology was found between the deduced amino acid sequence of p36 and any protein sequences compiled in the GenBank indicating that p36 is a novel mycobacterial protein. The reactivity of 199 serum samples was tested against the p36 by immunoblotting technique. Sera from 77 of 89 (86.5%) Crohn's disease patients and 16 of 18 (89%) sera from patients with tuberculosis and leprosy reacted with p36 compared to 5 of 42 (12%) ulcerative colitis and non-IBD control sera (p < 0.0001). In addition, p36 reacted to all sera from 10 normal controls that were Bacillus Calmette-Guerin (BCG)-immunized and only to 10% of 40 normal controls that were not BCG-immunized. The fact that sera from Crohn's disease patients reacted to p36 with the same high frequency as the sera from patients that were exposed to mycobacterial antigens further supports the hypothesis of the mycobacterial etiology in Crohn's disease.

Sequential intrahepatic fluorodeoxyuridine and systemic fluorouracil plus leucovorin for the treatment of metastatic colorectal cancer confined to the liver

PURPOSE

Extrahepatic metastasis represents a frequent pattern of disease progression when fluorodeoxyuridine (FUDR) is given by the intraarterial route for the treatment of unresectable colorectal liver metastases. Systemic fluorouracil (5-FU) plus leucovorin was added to intrahepatic FUDR to prolong the duration of disease control.

METHODS

Only patients with colorectal cancer who had evidence of unresectable metastases confined to the liver were eligible. Laparotomy was performed to establish arterial perfusion of the liver. Cycles of intrahepatic FUDR followed by a 1-week rest period then intravenous chemotherapy with 5-FU plus leucovorin were administered until maximal regression of hepatic metastases. Maintenance chemotherapy with 5-FU plus leucovorin was then given until disease progression.

RESULTS

Fifty-seven patients entered this trial; four patients (7%) were ineligible and 13 (23%) did not receive any chemotherapy on study because of findings at laparotomy. The 40 eligible patients who began chemotherapy are included in the statistical analyses. Twenty-five patients (62% of those who received chemotherapy) experienced regression of liver metastases. The median time to tumor progression was 9 months, but only 3% remained progression-free at 24 months. The median survival duration was 18 months. Toxicity was tolerable with no cases of biliary sclerosis. One treatment-related fatality due to sepsis was observed.

CONCLUSION

Although short-term treatment results appear to be somewhat better than we have previously observed with intrahepatic FUDR alone, the sequential regimen did not have an impact on long-term, progression-free survival in patients with unresectable liver metastases. We are now investigating this regimen as surgical adjuvant therapy in selected patients following hepatic metastasectomy where this aggressive approach might have a greater therapeutic effect in the minimal residual disease setting.

5-Fluorouracil and leucovorin therapy in patients with hormone refractory prostate cancer: an Eastern Cooperative Oncology Group phase II study (E1889)

This report is a multi-institutional phase II study designed to obtain the response rate, survival, and toxicity profile for patients having hormone-refractory prostate cancer. Patients who had bidimensionally measurable prostate carcinoma in first or second remission after previous hormonal therapy but no history of chemotherapy were eligible. Patients were treated with leucovorin, 20 mg/m2 intravenously, followed by 5-fluorouracil (5-FU), 425 mg/m2 intravenously daily for 5 days, with cycles repeated every 28 days. Of 38 eligible patients, 3 (7.9%) had partial responses to therapy and 20 (52.6%) had stable disease. Median survival was 11.6 months for all 38 patients and median time to progression was 4.4 months. Most of the serious side effects were gastrointestinal or hematologic and overall, 23 of 38 patients (60.5%) experienced at least one grade 3 or 4 treatment-related toxicity of any type, as measured by the National Cancer Institute common toxicity criteria. Five patients (13.2%) withdrew from the study because of adverse reactions from chemotherapy. We conclude that treatment of hormone-refractory prostate cancer patients with 5-FU and leucovorin chemotherapy produced few responses at the cost of significant side effects. Further investigation of this combination is not warranted in this setting.

Targeted disruption of guanosine diphosphate-dissociation inhibitor for Rho-related proteins, GDID4: normal hematopoietic differentiation but subtle defect in superoxide production by macrophages derived from in vitro embryonal stem cell differentiation

The Rho subfamily of small guanosine triphosphate (GTP)-binding proteins, through their role in cytoskeletal organization, is involved in diverse cellular functions, including cell motility and morphologic changes during differentiation. Rac also has a special role in the production of superoxide, a key component in phagocytic antimicrobial function. Guanosine diphosphate (GDP)-dissociation inhibitors (GDIs) belong to one of three classes of proteins that regulate the critical cycling of GTP-binding proteins between the inactive and active states. Two homologous GDIs for the Rho subfamily have been identified. GDID4 is preferentially expressed in hematopoietic cells, while RhoGDI is ubiquitously expressed. Whether different physiologic functions are subserved by the two GDIs is unknown. We have derived embryonal stem (ES) cells with targeted disruption of both alleles of the GDID4 gene and examined hematopoiesis and phagocytic functions of macrophages derived from in vitro ES-cell differentiation. GDID4-/- ES cells develop like wild-type cells into colonies that contain heterogeneous populations of progenitor cells and differentiated erythromyeloid cells. GDID4-/- cells express no GDID4 protein, but have normal levels of RhoGDI. GDID4-/- macrophages phagocytose yeasts and antibody-opsonized erythrocytes as effectively as wild-type macrophages. However, a slight but consistent reduction in their capacity to generate superoxide was observed, which suggests new insight into the cellular role of GDID4. The minimal phenotypic effect of a loss of function of GDID4 also indicates a significant redundancy of function between GDID4 and RhoGDI. Their functional repertoire may be better revealed by a disruption of both genes. The use of hematopoietic cells derived in vitro from genotypically altered ES cells avoids the difficulties inherent in generating knockout animals and is a useful complementary approach for evaluating the gene function.

Relationship of oral contraceptives and the intrauterine contraceptive devices to the regression of concentrations of the beta subunit of human chorionic gonadotropin and invasive complications after molar pregnancy

One hundred ninety-four patients with pathologically confirmed molar pregnancy and intact uteri were studied prospectively. Group A included 177 patients in whom the beta subunit of human chorionic gonadotropin (hCG-beta) declined to normal (less than 5 mlU/ml) without chemotherapy, whereas group B included 17 patients with invasive complications in the postmolar phase which necessitated the use of chemotherapy. Only women with intact uteri were included in the study. In group A, there were no significant differences in the human chorionic gonadotropin (hCG) positive interval between women who used intrauterine contraceptive devices, barrier and other methods, and those who used oral contraceptives. Differences in the proportions of women in groups A and B who used the oral contraceptives and intrauterine contraceptive devices were not observed. However, the mean dosage of estrogen and the proportion of women who ingested more than 50 micrograms of estrogen were higher in group B. These data suggest that (1) the oral contraceptives with less than 50 micrograms of estrogen and the intrauterine contraceptive devices do not prolong the hCG-beta positive interval nor increase the risk of invasive complications in the postmolar phase which requires the use of chemotherapy; and (2) the dose of estrogen (in formulations that contain more than 50 micrograms) rather than the oral contraceptives per se may influence the risk of these postmolar complications.

Prolactin, estradiol, and thyroid hormones in umbilical cord blood of neonates with and without hyaline membrane disease: a study of 405 neonates from midpregnancy to term

Concentrations of prolactin (PRL), estradiol (E2), thyroxine (T4), triiodothyronine (T3), and reverse T3 in umbilical cord blood were measured by radioimmunoassay in neonates with (n = 60) and in a control group without (n = 345) hyaline membrane disease. Mean levels of all hormones assayed were not significantly different between the two groups at various stages of gestation. In the control group, gestational age correlated positively with PRL and inversely with reverse T3, whereas birth weight correlated positively with PRL, T4, and T3, but inversely with reverse T3 levels. Thus, larger, more mature neonates tended to have higher cord levels of PRL, T4, T3 and lower concentrations of reverse T3. The data also suggest that, in the premature neonate, various obstetric complications and exposure in utero to beta-mimetic drugs and glucocorticoids may be important determinants of the concentrations of E2 and thyroid hormone in cord blood.

Regression of pituitary microadenoma during and following bromocriptine therapy: persistent defect in prolactin regulation before and throughout pregnancy

During 5 years of clinical, endocrinologic, and radiologic observations in a woman with a microprolactinoma treated medically with bromocriptine for 29 months, serial hypothalamic-pituitary studies revealed a defect in lactotrope function after prolactin (PRL) concentrations and ovulation were restored to normal. This defect persisted throughout a spontaneously conceived pregnancy in which the PRL, estradiol, and progesterone levels were subnormal, while, the dehydroepiandrosterone sulfate levels were normal and estriol concentrations were elevated. Levels of the beta subunit of human chorionic gonadotropin (hCG) were close to and slightly above the normal ranges. These observations are consistent with a role for PRL, interacting with hCG, in the control of estrogen and progesterone secretion by the fetoplacental unit. Lactation was initiated and maintained post partum. Pituitary function and PrL responses to suckling suggested improved lactotrope function 22 to 25 months after withdrawal of bromocriptine. The impaired lactotrope function, therefore, did not preclude normal implantation, pregnancy maintenance, onset of parturition, fetal development, and lactation.