Favorable Biological Characteristics Research Articles

Laboratory Host Range Testing of the Flea Beetle, PSEUDOLAMPSIS GUTTATA (LeConte) (Coleoptera: Chrysomelidae), A Potential Natural Enemy for Red Water Fern, AZOLLA FILICULOIDES Lamarck (Pteridophyta: Azollaceae) in South Africa

The flea beetle, Pseudolampsis guttata (LeConte) (Coleoptera: Chrysomelidae) was assessed for release on the South American fern, Azolla filiculoides Lamarck (Pteridophyta: Azollaceae) which is invasive in aquatic ecosystems in South Africa. Favourable biological characteristics of the beetle include: long-lived and mobile adults, short generation time, high rate of increase and high per capita feeding rates. However, laboratory host specificity trials indicated that this beetle is an oligophagous species capable of utilizing several species in the genus Azolla and could pose a threat to native southern African Azolla species. Pseudolampsis guttata was therefore considered unsuitable for release in South Africa.

Preparation and biological evaluation of 188Re-ethylenediamine-N,N,N',N'-tetrakis(methylene phosphonic acid) as a potential agent for bone pain palliation.

This study was undertaken in order to prepare 188Re labelled ethylenediamine-N,N,N',N'-tetrakis(methylene phosphonic acid) (EDTMP), and to determine its potential as a therapeutic radiopharmaceutical for the palliation of metastatic bone pain. The effects of pH, incubation methods, and concentrations of stannous chloride, EDTMP, and ammonium perrhenate as a carrier on radiochemical yield and stability were evaluated. Biodistribution studies were performed in male Wistar rats after intravenous injection of 188Re-EDTMP and compared with those of hydroxyethylidene diphosphonate (HEDP). Greater than 95% radiochemical yield of 188Re-EDTMP was obtained under the optimal conditions (0.1 mmol x ml(-1) of EDTMP, 0.5 mg x ml(-1) of stannous chloride, and pH 1.0). Heating the reaction mixture (boiling water for 15 min, and microwave heating for 15 s) and the addition of ammonium perrhenate increased the radiochemical stability (>90% at 3 h, and >80% at 48 h). The biodistribution of 188Re-EDTMP showed high bony uptake and rapid clearance from other organs, and high bone-to-soft tissue ratios, which are similar to 188Re-HEDP. In conclusion, 188Re-EDTMP was prepared with high radiochemical yield and stability, and showed favourable biological characteristics. Microwave heating was a convenient and rapid method for the preparation of 188Re-EDTMP. It is considered that 188Re-EDTMP is a potential therapeutic agent for bone metastasis.

Biological control ofDiaphorina citri(Hemiptera: Psyllidae) in Guadeloupe by importedTamarixia radiata(Hymenoptera: Eulophidae)

Introduction. The Asian citrus psyllid, Diaphorina citri Kuwayama, is particu- larly harmful to citrus plantations as it is one of the two psyllid vectors of the citrus greening disease or Huanglongbing. This disease, which limits the longevity of trees, is due to an intra- cellular bacterium which mainly affects the phloem. Past experience of biological control of D. citri in Reunion Island. In Reunion Island, this disease, detected in 1967, was the main obstacle to the development of the cultivation of citrus fruit. Control of the vector D. citri, by introducing from India and multiplying on site the specific parasitoid Tamarixia radiata (Waterston), was carried out during 1978 when nearly 4600 adult parasitoids were released. The success of T. radiata combined with the distribution of healthy plant material was at the origin of the revival of the cultivation of citrus fruit in Reunion Island. Programme for a biological control of D. citri in Guadeloupe. In Guadeloupe, D. citri was reported in Jan- uary 1998. No trace of insect parasitism was found and only one fungus, Hirsutella citriformis Speare, proved, under certain conditions, capable of regulating the populations of this psyl- lid. Taking into account the experience in Reunion Island and that the greening disease has not shown up in Guadeloupe, the introduction of T. radiata from Reunion Island was made in January 1999. About 1000 T. radiata were released all over the Guadeloupe islands. At pres- ent, just a little more than 1 year after the last releases, the parasitoid is established and pres- ent in almost all the citrus orchards where psyllid populations have decreased considerably. Quite favorable biological characteristics play a great part in explaining the excellent effec- tiveness of T. radiata in biological control programmes against D. citri. France (Reunion) / France (Guadeloupe) / Citrus / Diaphorina citri / Tamarixia radiata / insect control / biological control organisms

The high level of hCDC10 gene expression in neuroblastoma may be associated with favorable characteristics of the tumor.

The biological behavior of neuroblastomas detected through mass screening (MS, </=1 year of age) and that of mass screening-negative later-presenting (MSN, >1 year of age) neuroblastomas have been reported to differ in many studies. To investigate the biological differences between these two groups, we analyzed the differences in mRNA profiles. We analyzed the mRNA profiles of MS and MSN neuroblastomas using differential display, and cloned and sequenced the bands differentially expressed between these two groups. Using the RNA analysis by polymerase chain reaction (RNA-PCR) method, the relative amount of mRNA in tumor tissue in each sample was measured. Associations between relative amount of mRNA and clinical and genetic variables related to patient prognosis and the effect of the level of mRNA expression on survival probability were investigated using statistical methods. Using differential display and RNA-PCR, we found that the mRNA for the human homologue of the yeast cdc10 gene (hCDC10) identified in Saccharomyces cerevisiae was expressed at a higher level in the MS group of patients than in the MSN group of patients (0.554 +/- 0.197 for MS neuroblastoma, n = 24 and 0.244 +/- 0.179 for MSN neuroblastoma, n = 10, P < 0.01), and this difference was suggested to be independent of the histologic subtype of tumor. A high level of hCDC10 mRNA expression in neuroblastomas (relative amount of hCDC10 mRNA > 0.35) was also suggested to be associated with younger age at diagnosis (</=1 year of age, P < 0.01), favorable clinical stage (I, II, and IVs, P < 0. 01), and favorable histology in the Shimada classification (P < 0. 01), whereas a low level of hCDC10 mRNA expression (relative amount of hCDC10 mRNA </=0.35) was suggested to be associated with the progression of clinical stage (P < 0.01) and N-myc gene amplification (>1 copy, P < 0.05). Patients with neuroblastomas with a high level of hCDC10 mRNA expression were suggested to have a better prognosis than those with a low level of hCDC10 mRNA expression (P < 0.01). A high level of hCDC10 mRNA expression in neuroblastomas may be associated with favorable clinical and biological characteristics, and the expression of hCDC10 mRNA in neuroblastomas may affect the clinical and biological characteristics of this type of tumor.

Pelvic neuroblastoma: Low mortality and high morbidity

Background/Purpose: Cervical, thoracic, and pelvic neuroblastomas are regarded as having a better outcome than abdominal primaries. The aim of the study was to analyze the results of treatment of pelvic neuroblastomas in our institution. Methods: The authors reviewed the records of 284 patients with neuroblastoma treated in our hospital during the period 1983 through 1998 and identified 17 (6%) with pelvic tumors. The revised International Neuroblastoma Staging System was used. Results: There were 6 patients with stage 1 disease, 8 with stage 2, 2 with stage 3, and 1 with stage 4 disease. Intraspinal extension of the tumor was present in 7 patients (41%). Except for one child with stage 4 disease, all patients underwent an attempt of tumor excision, and 6 had a complete resection. All 7 patients with intraspinal tumor survived. Permanent postoperative neurological complications occurred in 6 patients (35%). These included sciatic nerve palsy, urinary and fecal incontinence, neuropathic bladder, and leg weakness or nerve root injury L4-S1. Three of 17 patients died, but 1 fatality was unrelated to the tumor. The overall survival rate was 82% and was not influenced by the completeness of tumor resection. Conclusions: The survival of nonmetastatic pelvic neuroblastoma in our institution is good despite incomplete tumor resection. Intraspinal extension is not a negative prognostic factor. Considering the high incidence of permanent neurological damage after surgery and the generally favorable biological characteristics of these tumors, surgical treatment should not be overaggressive. J Pediatr Surg 35:724-728. Copyright © 2000 by W.B. Saunders Company.

Tumor characteristics and clinical outcome of elderly women with breast cancer.

The number of elderly patients with breast cancer is increasing. Limited age-related information available about this disease prompted this study. The study population was derived from 50828 and 256287 patients with invasive breast cancer in San Antonio breast cancer databases and the Surveillance, Epidemiology, and End Results (SEER) registry, respectively. Tumor biologic and clinical characteristics, local and systemic therapies, and survival according to the patient's age were analyzed. Survival was also compared with that of age-matched women from the general population. In patients 55 years old or older, there was an association between increasing age at diagnosis and the presence of more favorable biologic characteristics of the tumor, including more tumors that express steroid receptors, lower proliferative rates, diploidy, normal p53, and absence of the expression of epidermal growth factor receptor and c-erbB2. In older patients with lymph node-negative disease and/or small tumors, the observed and expected survivals were almost identical. In the SEER registry, the 8-year survival of lymph node-negative patients relative to the expected survival of age-matched women from the general population was 1.01 (95% confidence interval [CI] = 0.98-1. 04) for patients 70-74 years old, 1.06 (95% CI = 1.01-1.11) for patients 75-79 years old, and 1.09 (95% CI = 0.98-1.20) for patients 80-84 years old. In women 55 years old or older, advancing age is associated with more favorable tumor biology, and breast cancer survival in older women is similar to survival in the general population irrespective of disease status. This favorable outcome should be considered when making clinical decisions in older patients.

Life History and Laboratory Host Range ofEccritotarsus catarinensis(Carvalho) (Heteroptera: Miridae), a New Natural Enemy Released on Water Hyacinth (Eichhornia crassipes(Mart.) Solms-Laub.) (Pontederiaceae) in South Africa

A mirid, Eccritotarsus catarinensis (Carvalho), was studied as a potentially damaging natural enemy for water hyacinth, ( Eichhornia crassipes (Mart.) Solms-Laub.), in South Africa. In the laboratory, eggs were inserted into the leaf tissue parallel to the leaf surface. The four nymphal instars fed gregariously with the adults mainly on the undersurface of the leaves, causing severe chlorosis at high population levels. The duration of immature stages (egg and nymphs) was approximately 23 days, while the adults survived for approximately 50 days. Favorable biological characteristics of E. catarinensis included a high rate of increase, gregarious habits, long-lived and mobile adults, and several generations per year. Laboratory host range of the mirid was determined by adult choice trials on 67 plant species in 36 families and adult no-choice trials on five species in the Pontederiaceae. Feeding was recorded on all Pontederiaceae tested and oviposition on four of the five species. However, these plant species proved to be inferior hosts for E. catarinensis in comparison to water hyacinth, suggesting that E. catarinensis would be an acceptable natural enemy for water hyacinth in South Africa.

177Lu-EDTMP

Lutetium-177 (177Lu) has both beta particle emissions for a therapeutic effect and gamma emissions for imaging. This study was undertaken to synthesize and evaluate 177Lu-EDTMP (ethylenediaminetetramethylene phosphonic acid) as a therapeutic radiopharmaceutical for the palliation of pain from bone metastases. Chelation of 177Lu to EDTMP was obtained by heating for 30 min in boiling water at pH 8.8, resulting in a radiochemical yield of over 99%. The compound was stable for 20 days without any appreciable dissociation. Biodistribution studies in normal rats indicated selective bone accumulation, showing faster blood clearance, higher bone uptake and higher bone-to-soft tissue ratios than 99Tcm-MDP. In conclusion, 177Lu-EDTMP has favourable biological and physical characteristics for the palliative treatment of painful bone metastases.

Cancer risk in women receiving estrogen-progestin replacement therapy

Objectives and methods: The epidemiological literature was reviewed in order to evaluate the relationship between hormone replacement therapy and risk of cancer in the breast and reproductive organs. Results: For breast cancer, there is no evidence of an overall increase in the risk. According to several studies, but not all, the duration of intake seems to affect the risk. Many years of intake of both estradiol compounds and conjugated estrogens can be assumed to increase the risk of breast cancer 1.5-2-fold. The addition of progestins does not seem to alter (reduce) the duration-risk relationship. The magnitude of risk increase is likely to be small and may be explained partly by methodological problems, or by differences in study populations. The prognosis in patients with HRT-related breast cancer seems to be more favourable than for non-exposed breast cancer patients. Because of the importance of the issue, and inconsistencies in results, further research is urgent. Especially, there is an urgent need to define sub-groups of women who would be susceptible to an adverse influence of HRT. Regarding endometrial cancer, a duration-dependent strong risk relationship with long-term intake of estrogens only is established. The level of risk increase is about 10-fold after 10 or more years of intake, a risk relationship that seems to decrease after discontinuation of treatment. Added progestins for at least 10 days per cycle can reduce or eliminate the risk increase. Tumors occurring after estrogen replacement have favourable biological characteristics. Future research will be needed to define the long-term safety of various progestin regimens. Ovarian cancer risk does not seem to be affected by HRT. Available data are inconsistent and contradictory. Due to the pronounced protective effect of oral contraceptives, further research is needed to measure effects of estrogen-progestin combined regimens. Cervical cancer risk has not been shown to be affected by HRT. Conclusions: It is concluded that hormone replacement therapy, with estrogens alone or estrogens combined with progestins, may have important effects on the risk of cancer, particularly in the breast and endometrium. Therefore, when making a risk-benefit assessment of long-term HRT, possible risk relationships should be considered.

Biology and Host Range of Gratiana spadicea (Klug, 1829) (Coleoptera: Chrysomelidae: Cassidinae), a Potential Biological Control Agent for the Weed Solanum sisymbriifolium Lamarck (Solanaceae) in South Africa

Abstract A leaf-feeding tortoise beetle (Gratiana spadicea) was screened as a potential biological control agent for the invasive exotic weed Solanum sisymbriifolium in South Africa. Favorable biological characteristics of G. spadicea include a high rate of increase, long-lived and mobile adults, several generations per year, and a high per capita feeding rate. Host range was investigated in larval survival tests and adult choice tests under laboratory conditions. Larvae were successfully reared on 8 of 11 indigenous Solanum species, on 4 of 5 exotic Solanum species (apart from S. sisymbriifolium), and on economically important S. melongena (eggplant) but not on any of the species of Datura, Nicandra, and Physalis tested. Very limited adult feeding and oviposition occurred on several of the indigenous Solanum species and on eggplant. These trials were conducted under quarantine conditions with the potential for laboratory artifacts. The poor larval survival on nonhosts and the inability of the agent to recognize nonhosts as oviposition sites supported a request for release of this agent, which was subsequently granted.

Environmental consequences of hydroelectric development: The role of facility size and type

The development of hydroelectric power throughout the world is receiving renewed attention as the economic, political, and environmental costs of conventional energy production rise. There is currently a perception that hydroelectricity has environmental and economic advantages over electricity produced by conventional energy technologies, but there is a paucity of information about the environmental impacts of hydroelectric facilities as a function of size and type. We characterize the environmental impacts of hydroelectric developments and quantify these impacts as a function of the size and type of project. Several unexpected conclusions arise from our analysis. For most hydroelectric facilities, size, as measured by installed capacity, is not necessarily a good indicator of the severity of environmental costs. For impacts such as land flooded and evaporative water lost, smaller facilities cause greater environmental disruptions per unit of energy produced than do larger facilities. A more striking conclusion, however, is that differences in the type of facility, as indicated by the relationship between dam height and gross static head, are often far more important from an environmental perspective than are differences in the installed electrical capacity of a facility. Another major conclusion is that the development of hydroelectric facilities (independent of their size) such as dams at new sites and dams operated to produce peak power are often accompanied by environmental and ecological disruptions comparable to or exceeding those of conventional non-hydroelectric energy facilities. These results suggest that there is no justification to expedite licensing procedures for hydroelectric facilities smaller than some arbitrarily chosen installed capacity, as currently permitted by some laws. Appropriate policies should emphasize the development of dams on the basis of other favorable physical, chemical, and biological characteristics.

Early results of ion beam radiation therapy for sacral chordoma. A Northern California Oncology Group Study.

The authors report on eight patients with sacral chordoma treated with ion beam radiation therapy. Ion beams have favorable physical and biological characteristics when compared to conventional radiation therapy beams of x-rays, gamma rays, or electrons. This treatment technique has been developed to exploit those advantages. With this technique it is possible to deliver a much higher tumor dose than that usually given with conventional beams, and to date no significant normal-tissue morbidity has been noted. Seven of the eight patients currently have local control of their tumor; however, follow-up time is too short to judge the long-term local control rate of this treatment technique.

Effects of Hyperparasites on Population Levels of Bathyplectes curculionis1 in Colorado 2

Cocoons of Bathyplectes curculionis (Thomson) often harbor hyperparasites. Emergence of all hyperparasites from diapause cocoons over a 5-yr period averaged 52.9%. Hyperparasites averaged 36% of the total emergence from diapause cocoons in 1969, increased to 74.1% in 1971%72, then dropped to the low of 29% in 1973–74. Emergence of all hyperparasites from nondiapause cocoons over a 3-yr period averaged 50.3%. Hyperparasites averaged 68.7% of the total emergence from nondiapause cocoons in 1970, then steadily decreased to the low of 36.3% during the last year. Populations of hyperparasites fluctuate from year to year which probably reflects environmental pressure. Most hyperparasites emerge from one type of cocoon (diapause or non-diapause) more than the other. The degree of hyperparasitism to larvae in either type of cocoon appears primarily dependent upon the predominance of one cocoon type (or formation of) over the other when hyperparasites emerge in the field. B. curculionis larvae in diapause cocoons are heavily hyperparasitized by S. grandiclava (Walker) and Mesochorus nigripes Ratzeburg, whereas those in nondiapause cocoons are heavily hyperparasitized by Mesochorus agilis Cresson and Eupteromalus americanus Gahan. The more important species have one or more favorable biological characteristics of multivoltinism, lack of diapause, extended longevity, or gregariousness.

Indium-113m diethylenetriaminepentaacetic acid (DTPA): a new radiopharmaceutical for study of the kidneys.

The short-lived radionuclide, indium 113m, obtained as a daughter product of tin 113, has been used in various chemical forms for different types of organ scanning (1–3). 113mIn emits 392-keV gamma rays and decays with a physical half-life of 1.7 hours. Diethylenetriaminepentaacetic acid (DTPA) combined with 113mIn has been found useful for brain scanning (2). Because of favorable biological and physical characteristics, multimillicurie amounts may be safely administered; these result in relatively high photon fluxes particularly suitable for external detection. We have now demonstrated that indium-DTPA is excreted primarily by glomerular filtration and believe this agent to be useful for renal scanning, renography, and the rapid estimation of glomerular filtration rate. Materials and Methods 113mIn-DTPA complex was prepared as suggested by Stern et al. (2). Twenty millicuries of 113mIn was eluted with 0.05 N HCl (about 8 ml initially) from a tin-113 generator. Two hundred μg of carrier iron (0.2 ml FeCl3...

The localization of octoiodofluorescein-I131 in human brain tumors

The efficiency of I/sup 131/-labeled, octoiodofluorescein (OIF-I/sup 131/ ) as an agent for localizing human brain tumors in situ was investigatod using a manually operated scanning device. The dye was found to produce no toxic symptoms in total doses up to 30 mg when given intravenously. Labeled OIF correctly localized the presence or indicated the absence of brain tumors in 34 of 47 (73%) patients in whom diagnoses were subsequently confirmed by surgical . methods. In 55 cases confirmed by clinical (nonsurgical) methods, 40, or 73%, were correctly detected. For the combined group of 102 patients, accuracy in localizing brain tumor with OIF-I/sup 131/ was 73%. In a comparative study between OIF-I/sup 131/i, Risa, and DIF-I/sup 131/, OIF-I/sup 131/ was found to have more favorable biological characteristics for external scanning purposes than the other 2 agents. Scanning with OIF-I/sup 131/ can be performed at any time from 2 to 48 hours after injection, the optimum time being between 5 and 24 hours. The amount of dye found in resected tumor tissue was as much as l0 times that in adjacent normal brain tissue. With the manual scanning technique employed, OIF-I/sup 131/ appears to be useful as a test for themore » external detection of brain tumors. With a more sensitive automatic scanning device there should be a higher percentage of correct results. (auth)« less