RESUMEN

BACKGROUND: The purpose of this study was to determine if body weight supported treadmill training (BWSTT) decreased metabolic and cardiovascular demand in older (50-74 years) healthy adults while walking a self-selected speed. The results of this study could impact clinician application to exercise therapy. METHODS: Twenty subjects (50% female, 58.3±7.3 years) completed 3, 5-minute treadmill walking trials at a self-selected pace, with 0%, 15%, and 30% body weight support (BWS). Blood pressure (BP), heart rate (HR), and oxygen uptake (V̇O2) were measured at rest, and during walking trials. Mean data from minutes 3-5 were analyzed for difference by repeated measures ANOVA and Bonferroni post-hoc test. RESULTS: At rest, HR was 70.8±8.2 bpm and BP was 126.8±12.2/84.3±8.6 mmHg. Mean walking speed was 67.1 m/min. Tested parameters during exercise trials were significantly (P<0.05) different from rest, but no significant differences were detected among the 3 exercise trials. CONCLUSIONS: In older adults walking at self-selected speeds, up to 30% BWS had no significant impact on metabolic or cardiovascular demand.

Asunto(s)

RESUMEN

BACKGROUND: Hypervirulent Klebsiella pneumoniae causes severe disseminated infections, typically with hepatic and central nervous system involvement including endophthalmitis. Case Presentation. We report a fatal case of an undocumented Chinese migrant in her 60s who presented to the emergency department with abdominal pain, lethargy, and headache over the preceding two weeks. She had a new diagnosis of diabetes mellitus on admission. Computed tomography scan of the thorax, abdomen, and pelvis showed bilateral pneumonia with liver abscesses. The patient was treated with empirical broad-spectrum antibiotics before K. pneumoniae was isolated from cerebrospinal fluid and blood cultures. The isolate was further characterised as a ST23 (ST: sequence type), serotype K1 hypervirulent strain using Nanopore sequencing. Despite admission to the intensive care unit, the patient died within 48 hrs of admission. CONCLUSIONS: This case demonstrates the need for increased awareness of hypervirulent K. pneumoniae, even in countries where it occurs infrequently. Novel, rapid, sequencing technologies can support diagnosis in unusual presentations.

RESUMEN

Juvenile, female and male nematodes were discovered in wood chips of white pine Pinus strobus from Ashley Falls, MA. Initial observations suggested these nematodes might be PWN, but closer morphological and molecular characterization proved otherwise. Comparison of measured features with those in the literature indicated this nematode population had some unique characteristics. The specimens were identified as Bursaphelenchus antoniae Penas et al., 2006 based on 18S rDNA molecular sequence vs only 95% similarity with PWN B. xylophilus. Compared to the previously described Portuguese population of B. antoniae, the sequences generated for the MA population were 98.3% similar in the ITS1, 2 rDNA and 99.9% similar for 28S rDNA. There was 99.2% similarity between the COI sequences of the US and Portuguese isolates of B. antoniae. This population has morphology consistent with that of Penas et al., 2006; however, the female tail on this MA pine population is mucronate and more attenuated than in B. antoniae from Portuguese P. pinaster found in association with Hylobius sp. Ecological associations of both populations of B. antoniae are discussed.Juvenile, female and male nematodes were discovered in wood chips of white pine Pinus strobus from Ashley Falls, MA. Initial observations suggested these nematodes might be PWN, but closer morphological and molecular characterization proved otherwise. Comparison of measured features with those in the literature indicated this nematode population had some unique characteristics. The specimens were identified as Bursaphelenchus antoniae Penas et al., 2006 based on 18S rDNA molecular sequence vs only 95% similarity with PWN B. xylophilus. Compared to the previously described Portuguese population of B. antoniae, the sequences generated for the MA population were 98.3% similar in the ITS1, 2 rDNA and 99.9% similar for 28S rDNA. There was 99.2% similarity between the COI sequences of the US and Portuguese isolates of B. antoniae. This population has morphology consistent with that of Penas et al., 2006; however, the female tail on this MA pine population is mucronate and more attenuated than in B. antoniae from Portuguese P. pinaster found in association with Hylobius sp. Ecological associations of both populations of B. antoniae are discussed.

RESUMEN

Blighting of Forsythia × intermedia 'Showoff' was first observed affecting several hundred plants in a commercial nursery in Connecticut in September 2012. Symptoms included wilting, leaf and stem blight, and dieback progressing to plant death. A Phytophthora sp. was isolated from symptomatic tissues on half-strength potato dextrose agar (½PDA). Colonies were white and cottony on ½PDA, reaching 9 mm in 15 days at 25°C, but colorless and inconspicuous on pimaricin, ampicillin, rifampicin, pentachloronitrobenzene agar (PARP) with sparse and limited aerial mycelium, reaching 60 mm in 15 days at 25°C. The characteristics of the pathogen were observed and measured from a 3-month-old colony on ½PDA. Sporangia were abundant, various in shape, ovoid, ellipsoid to pyriform or limoniform, occasionally gourd shaped or irregular; (17.9) 27.2 to 41.4 (47.3) × (12.6) 19.1 to 30.5 (36.7) µm (n = 30), length/breadth ratio 1.4 ± 0.2, papillate and noncaducous. Papillae measured 2.9 ± 0.8 × 3.4 ± 0.8 µm (n = 10). Chlamydospores were present, 23.4 ± 3.1 × 22 ± 3.3 µm (n = 10). Oogonia and oospores were not observed. Arachnoid mycelia were present. These morphological characteristics are consistent with Phytophthora nicotianae Breda de Haan (1). The identity of the pathogen was confirmed as P. nicotianae by BLAST analysis of ITS, Cox II, and beta tubulin gene sequences (99% match for the three sequences, E value = 0). Pathogenicity tests were conducted four times on healthy liners of Forsythia × intermedia 'Showoff' grown in 10-cm-diameter pots. Leaves and stems were wounded by pricking with a sterile needle and six plants were inoculated with 0.25 cm2 plugs of the pathogen growing on ½PDA placed on three leaves and in three stem nodes and covered with Parafilm. Controls consisted of an equal number of plants wounded and inoculated with ½PDA alone. All plants were placed inside high humidity chambers for 24 h and then transferred to a greenhouse for up to 1 month. Typical symptoms developed within 1 week of inoculation and the pathogen was re-isolated from diseased tissue. Disease incidence was nearly 100% of inoculated leaves and stems and not observed in control plants without the pathogen. Three replicate 6-week-old broadleaf tobacco 'C9' plants were each inoculated with tobacco or forsythia isolates of P. nicotianae or sterile media alone, by wounding stems and placing colonized 0.25 cm2 ½PDA plugs into wounds and covering with Parafilm. After 1 week, stems were split and the length of internal necrosis in the stem measured. Disease resulted from inoculation with both the tobacco and forsythia isolates and stem necrosis averaged 43 and 23 mm for tobacco or forsythia isolates, respectively. No necrosis was observed in the pathogen-free controls. P. nicotianae has been reported from the basal stem and roots of F. viridissima in Italy (2) and from shoots of Forsythia × intermedia in Virginia (3). To our knowledge, this is the first report of P. nicotianae causing shoot blight on Forsythia in the northeastern United States. References: (1) J. van. Breda de Haan. Mededeelingenuit's Lands Plantentuin Batavia. 15:57, 1896. (2) S. O. Cacciola et al. Plant Dis. 78:525, 1994. (3) C. X. Hong et al. Plant Dis. 89:430, 2005.

RESUMEN

Phosphonates are characterized by a stable carbon-phosphorus bond and commonly occur as lipid conjugates in invertebrate cell membranes. Phosphonoacetate hydrolase encoded by the phnA gene, catalyses the cleavage of phosphonoacetate to acetate and phosphate. In this study, we demonstrate the unusually high phnA diversity in coral-associated bacteria. The holobiont of eight coral species tested positive when screened for phnA using degenerate primers. In two soft coral species, Sinularia and Discosoma, sequencing of the phnA gene showed 13 distinct groups on the basis of 90% sequence identity across 100% of the sequence. A total of 16 bacterial taxa capable of using phosphonoacetate as the sole carbon and phosphorus source were isolated; 8 of which had a phnA+ genotype. This study enhances our understanding of the wide taxonomic and environmental distribution of phnA, and highlights the importance of phosphonates in marine ecosystems.

Asunto(s)

RESUMEN

During August 2007 and again in January 2008, compact sweet basil (Ocimum basilicum 'Genovese') plants grown hydroponically in Indiana displayed dark, irregular, stem lesions extending 2 to 3 cm above the interface of the nutrient solution. These necrotic stem lesions (black leg), observed on 20 to 30% of the basil plants caused very weak, brittle stems so that they could not be marketed fresh. Although no wilting was noted, reduced plant height was observed. Similar symptoms of blackleg and poor growth have been reported from Italy on greenhouse-grown basil infected with Microdochium tabacinum (1,2). Diseased plant samples were sent to diagnostic clinics at Purdue University and the University of Massachusetts. Stem samples were surface sterilized and plated on potato dextrose agar (PDA) acidified with 1 ml of 85% lactic acid per liter as well as onto one-quarter-strength PDA. A fungus morphologically consistent with Plectosporium tabacinum (van Beyma) M.E. Palm, W. Gams, & H.I. Nirenberg (synonyms M. tabacinum (von Arx, 1984) and Fusarium tabacinum (Gams & Gerlagh, 1968) (3) was cultured from the basil stems and identified as P. tabacinum by R. Wick. Cultures sent to J. McKemy and J. Bischof (USDA/APHIS/PPQ) and W. Elmer (Connecticut Agricultural Experiment Station) also were identified as P. tabacinum. Amplification of the 323-bp internal transcribed spacer (ITS) region (ITS1, 5.8S rRNA gene, ITS2) and subsequent BLAST alignments of the resulting sequence indicated a 98% match for Plectosphaerella cucumerina (anamorph P. tabacinum) (GenBank Accession No. U17399; MIDI Inc., Newark, DE). Inoculations were performed on basil plants grown in peat-based soilless medium in a greenhouse for 6 weeks. Immediately before inoculation, the roots were washed with tap water to remove the peat-based medium. A single basil plant was placed in each of eight, 125-ml Erlenmeyer flasks. Four flasks were filled with 100 ml of deionized water as negative controls and four were filled with a 1 × 106 CFU/ml water suspension of P. tabacinum so that the liquid reached the crown of the basil plant. Basil plants in the Erlenmeyer flasks were incubated on a laboratory bench at 23°C. After 24 h, the solutions in all flasks were discarded and each flask and root system was rinsed three times with deionized water. The plants were then incubated in deionized water on the laboratory bench for four to five additional days. Within 4 days, dark brown-to-black stem lesions similar to those observed originally on basil plants in the hydroponic production greenhouse developed on the plants at the water interface and extended up the stem. Lesions extended a mean of 22 mm above the water level on inoculated plants. Control plants remained symptomless. P. tabacinum was recovered from symptomatic tissue of inoculated plants to complete Koch's postulates. The experiment was repeated several times with similar results. Further evidence of pathogenicity was obtained by stem inoculation of basil plants growing in a soilless medium. These data indicate that P. tabacinum was the causal agent of the symptoms observed on the hydroponic basil. To our knowledge, this is the first report of P. tabacinum causing 'black leg' and reduced growth on basil in the United States and the first report in the world of P. tabacinum on hydroponic basil. References: (1) A. Garibaldi et al. Plant Dis. 81:124.1997. (2) A. Matta. Riv. Patol. Veg. Ser. IV 14:119, 1978. (3) M. Palm et al. Mycologia. 87:397.1995.

RESUMEN

In September of 2008, downy mildew was discovered to be causing a serious foliar blight of sweet basil at several farms and greenhouses in Massachusetts. Infected leaves had chlorotic vein-bounded patches and diffuse chlorosis, and a characteristic gray, fuzzy growth was on the abaxial surface. Microscopic observations revealed branched sporangiophores that measured 187.5 to 325 µm (average 285 µm) long. Sporangia measured 22.5 to 30 × 20 to 22.5 µm (average 26.7 × 20.9 µm). No oospores were found. Sporangium measurements are comparable to unnamed Peronospora species reported previously on basil from Italy, Switzerland, and South Africa (1,2). Sequence analyses were conducted on five isolates of 'Nufar' basil by extracting DNA from a sporangial suspension washed from leaves and infected leaf tissues using the Qiagen DNeasy plant tissue kit (Qiagen, Valencia, CA). PCR amplification of the ITS1, 5.8S, and ITS2 region was performed using primers ITS6 and ITS4 (3). The sequences of the five isolates were identical. BLAST analyses of the sequences revealed a 99% similarity to the unnamed Peronospora species on sweet basil in Europe and South Africa (1,2). To our knowledge, this is the first report of a Peronospora species on sweet basil in Massachusetts. References: (1) L. Belbahri et al. Mycol. Res. 109:1276, 2005. (2) A. McLeod et al. Plant Dis. 90:1115, 2006. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

RESUMEN

OBJECTIVE: To investigate long-term health effects in AS patients treated with (224)Ra. METHODS: A prospective epidemiological study has been carried out on 1471 AS patients treated with repeated intravenous injections of (224)Ra between 1948 and 1975. These patients have been followed together with a control group of 1324 AS patients not treated with radioactive drugs and/or X-rays. Numbers of malignancies expected in a normal population were computed from German and Danish cancer registry data. RESULTS: After a mean follow-up time of 26 yrs in the exposed group or 25 yrs in the control group, causes of death have been ascertained for 1006 exposed patients and 1072 controls. In particular, 19 cases of leukaemia were observed in the exposure group (vs 6.8 cases expected, P < 0.001) compared to 12 cases of leukaemia in the control group (vs 7.5 cases expected). Further subclassification of the leukaemia cases demonstrated a high increase of myeloid leukaemia in the exposure group (11 cases observed vs 2.9 cases expected, P < 0.001), especially a high excess of acute myeloid leukaemias (7 cases observed vs 1.8 cases expected, P = 0.003), whereas in the controls the observed cases are within the expected range (4 myeloid leukaemias vs 3.1 cases expected). CONCLUSIONS: The enhanced leukaemia incidence in the exposed group is in line with results from experiments in mice injected with varying amounts of the bone-seeking alpha-emitter (224)Ra. In these studies, in animals exposed to lower doses of (224)Ra, i.e. at doses lower than those found to induce osteosarcomas, an increased risk of leukaemia was observed.

Asunto(s)

RESUMEN

The European Radiobiology Archives (ERA), supported by the European Commission and the European Late Effect Project Group (EULEP), together with the US National Radiobiology Archives (NRA) and the Japanese Radiobiology Archives (JRA) have collected all information still available on long-term animal experiments, including some selected human studies. The archives consist of a database in Microsoft Access, a website, databases of references and information on the use of the database. At present, the archives contain a description of the exposure conditions, animal strains, etc. from approximately 350,000 individuals; data on survival and pathology are available from approximately 200,000 individuals. Care has been taken to render pathological diagnoses compatible among different studies and to allow the lumping of pathological diagnoses into more general classes. 'Forms' in Access with an underlying computer code facilitate the use of the database. This paper describes the structure and content of the archives and illustrates an example for a possible analysis of such data.

Asunto(s)

RESUMEN

The European Radiobiology Archives (ERA) aims to collect most of the information still available in Europe on long-term animal experiments--including some selected human studies suitable for comparison with animal data--and to make them available to the scientific community for further analysis. ERA cooperates with the US (National Radiobiology Archives, NRA) and Japan (Japanese Radiobiology Archives, JRA) in the International Radiobiology Archives (IRA).

Asunto(s)

RESUMEN

A study was done to determine the efficacy of aqueous ozone treatment in killing Listeria monocytogenes on inoculated alfalfa seeds and sprouts. Reductions in populations of naturally occurring aerobic microorganisms on sprouts and changes in the sensory quality of sprouts were also determined. The treatment (10 or 20 min) of seeds in water (4 degrees C) containing an initial concentration of 21.8 +/- 0.1 microg/ml of ozone failed to cause a significant (P < or = 0.05) reduction in populations of L. monocytogenes. The continuous sparging of seeds with ozonated water (initial ozone concentration of 21.3 +/- 0.2 microg/ml) for 20 min significantly reduced the population by 1.48 log10 CFU/g. The treatment (2 min) of inoculated alfalfa sprouts with water containing 5.0 +/- 0.5, 9.0 +/- 0.5, or 23.2 +/- 1.6 microg/ml of ozone resulted in significant (P < or = 0.05) reductions of 0.78, 0.81, and 0.91 log10 CFU/g, respectively, compared to populations detected on sprouts treated with water. Treatments (2 min) with up to 23.3 +/- 1.6 microg/ml of ozone did not significantly (P > 0.05) reduce populations of aerobic naturally occurring microorganisms. The continuous sparging of sprouts with ozonated water for 5 to 20 min caused significant reductions in L. monocytogenes and natural microbiota compared to soaking in water (control) but did not enhance the lethality compared to the sprouts not treated with continuous sparging. The treatment of sprouts with ozonated water (20.0 microg/ml) for 5 or 10 min caused a significant deterioration in the sensory quality during subsequent storage at 4 degrees C for 7 to 11 days. Scanning electron microscopy of uninoculated alfalfa seeds and sprouts showed physical damage, fungal and bacterial growth, and biofilm formation that provide evidence of factors contributing to the difficulty of killing microorganisms by treatment with ozone and other sanitizers.

Asunto(s)

RESUMEN

From 1999 to 2001, a Massachusetts nursery received a number of shipments of Pothos, Epipremnum aureum (Lindl. & André) Bunting, with significant crown, petiole, and leaf rot. The plants were imported from Costa Rica. Sporangia were observed on diseased tissues, and five presumptive isolates of Phytophthora were recovered from infected petioles and stems for species identification. The five isolates were morphologically indistinguishable from each other. Sporangia were produced in water and on V8 juice agar under fluorescent light at 22°C. Mating type was determined by pairing isolates with A1 and A2 mating types of Phytophthora capsici Leonian. Sporangial measurements were taken from water cultures. Determination of caducity, and measurements of pedicels and oospores were taken from V8 agar cultures. Measurements represent an average of 50 observations a single isolate. In water culture, sporangia were borne in umbellate clusters. Sporangium length/breadth was 48.29 and 22.33 µm respectively; length/breadth ratio 2.16. On solid media, sporangia were upright and caducous. The bases of the sporangia were mostly tapered. Pedicel lengths were 22 to 49 µm (average 35 µm). Oogonia had amphigynous antheridia and developed only in the presence of an opposite mating type, and oospores measured 25.74 µm diameter. All five isolates were the A1 mating type. Chlamydospores were absent in V8 and corn meal agar (CMA) cultures. Metalaxyl sensitivity was determined at 0, 0.1, 0.5, and 5 ppm in CMA with five replications. The isolate was completely sensitive to 5 ppm metalaxyl, but grew as well as the controls at 0.1 ppm metalaxyl. Growth response to temperature was determined on V8 agar at 15, 20, 25, 30, and 35°C in five replications. After 4 days, colony diameters at 20, 25, and 30°C were not significantly different (P = 0.01) and colonies filled the 100-mm petri dishes. At 15 and 35°C, average colony diameter was 65.7 and 71.4 mm, respectively. Based on the above characteristics, the isolates were identified as P. capsici. Koch's postulates were carried out on pepper, Capsicum annuum 'Italia', squash, Cucurbita pepo 'Patty Pan' seedlings, and rooted cuttings of pothos. Pepper and squash seedlings and rooted pothos were transplanted in 4-in. (10 cm) pots containing a soilless growing medium (Metro Mix 360, W.R. Grace, Columbia, MD). Phytophthora cultures were grown on V8 juice agar for 4 days. An agar culture was added to 200 ml of sterile distilled water and briefly blended. Ten milliliters of the resulting mycelial slurry were pipetted in the soil one cm from the crown on two sides of the plant. Controls received no mycelial slurry. Petiole, leaf, and crown rot of pothos developed within 2 weeks following inoculation. Squash and pepper plants did not become diseased. In a second pathogenicity test, a 1-cm-diameter plug of mycelial growth from a V8 agar culture was placed between the stem and petiole of the lowest leaf of pothos cuttings directly after transplanting. Inoculated plants died within 3 days. The development of umbellate clusters of sporangia, sporangial shape, length/breadth ratio, and lack of pathogenicity to pepper suggest that the P. capsici isolated from pothos belong to the CAPB (tropical) subgroup of Mchau and Coffey (2). References: (1) S. S. A. Al-Hedaithy and P. H. Tsao. Mycologia 71:392, 1979. (2) G. R. Mchau. and M. D. Coffey. Mycol. Res. 99:89, 1995.

RESUMEN

Commercial plantings of summer squash in Charlemont, Franklin County, MA, were decimated in 1999 by 100% incidence of a yellowing disease resembling cucurbit yellow vine disease (CYVD) (1). Both plantings were established in the same field during the third week of May, one with transplants and the second by direct-seeding. Each planting consisted of four 30-m rows each of yellow zucchini (Cucurbita pepo cv. Gold Rush), summer squash (C. pepo cv. Seneca Prolific), and zucchini (C. pepo cv. Condor). Crops were produced organically and pyrethrum was used to control a high infestation of squash bugs, Anasa tristis (De Geer) (Heteroptera:Coreidae), a putative vector of CYVD (3). Just prior to fruit set, during the first two weeks of June, plants began showing symptoms of foliar chlorosis, plant stunting, or both. All of the plants in the field eventually wilted and collapsed. Cross-sections of the below-ground stem and primary root revealed a honey-brown phloem discoloration and healthy appearing xylem, symptoms characteristic of CYVD. Plants yielded marketable fruit for only about 1 week. When plant samples were tested by polymerase chain reaction (PCR) with CYVD bacterium specific primers (2), a band of the expected size for the CYVD bacterium, identified as Serratia marcescens based on 16s rDNA and groE sequence analyses (4), was amplified in every case. Since all plant samples collected were symptomatic and PCR positive for S. marcescens, asymptomatic greenhouse plants were run simultaneously as a control. All control plants tested negative. A third planting, similar to the two disease-affected plantings and containing the same three squash cultivars from the same seed lot, was established at about the same time approximately 3 km away. No symptoms of CYVD occurred at this site, further evidence that the pathogen is not seed-borne (1). Furthermore, squash bugs were not observed in this field. In 2000, the disease was observed in a planting of 'Atlantic Giant' pumpkin in Erving, Franklin County, MA, and confirmed by PCR. Until now, CYVD has been reported only in the states of Oklahoma, Texas, and Tennessee. Confirmation of the disease in Massachusetts significantly increases the known geographical range of CYVD to include the New England area. References: (1) B. D. Bruton et al. Plant Dis. 82:512-520, 1998. (2) U. Melcher et al. Phytopathology 89:S95, 1999. (3) S. D. Pair et al. Pages 145-148 in: Proc. 19th Ann. Hort. Conf., Okla. State Univ. (4) J. Rascoe et al. Phytopathology 90:S63, 2000.

RESUMEN

The human histones H1 zero and H1.2 were expressed in E. coli and purified to homogenity. Their cytotoxicity on the human leukemia cell line K562 and on PBMC from healthy volunteers was compared with the cytotoxic effect of a bovine histone H1 preparation. In this preparation, histone H1.2 was identified as the main compound. All three histone preparations induced a significant dose-dependent toxicity on the leukemia cell line. Compared with the recombinant histone H1 zero, the bovine preparation and recombinant H1.2 showed stronger cytotoxicities. Cytotoxic effects on K562 cells were observed immediately after addition of the histones, whereas the histone preparations failed to induce significant cytotoxicity on PBMC during the first hour of incubation. However, after 24 hours all three histone preparations induced toxic effects on PBMC which were comparable to those observed on the leukemia cell line.

Asunto(s)

RESUMEN

This study is comprised of 1577 ankylosing spondylitis patients from 9 German hospitals who have been treated with multiple injections of (224)Ra. The majority of the patients, most of them treated in the years 1948-1975, received one series of 10 weekly intravenous injections of about 1 MBq of (224)Ra each. This dose leads to a mean absorbed dose due to alpha-particle radiation of 0.56 Gy to the marrow-free skeleton of a 70- kg man (mean bone surface dose of about 5 Gy). To provide comparative information on causes of death and on health effects possibly related to the basic disease itself, a control group of 1462 ankylosing spondylitis patients with roughly the same age distribution has been established. By the end of 1998, 649 patients in the exposed group and 762 control patients had died. Among other observations, it is of particular interest that 13 cases of leukemia in the exposed group have been observed. This is a highly significant excess (P < 0.001) compared to a standard population, but only a marginally significant excess in comparison to the seven cases observed in the control group. Subclassification of the leukemias shows a clear preponderance of the myeloid leukemias in the exposed group (8 cases observed compared to 1.7 cases expected, P < 0.001), whereas in the control group the observed cases are within the expected range for myeloid leukemia (3 cases observed compared to 2.2 cases expected, P = 0.3). The (224)Ra cohort of the earlier study (higher-dose group) has provided a risk coefficient that predicts about 8 excess malignant bone tumors for the irradiated cohort in this study. In actuality, 4 cases of malignant tumors in the skeleton have been observed so far. However, excess of breast cancer has not been observed in either the irradiated or the control group, which is in contrast to the findings in the earlier (224)Ra cohort of Study I.

Asunto(s)

RESUMEN

BACKGROUND: Patients who receive bone marrow transplants have increased risk for new malignant conditions because of several risk factors, including conditioning with radiation and chemotherapy, immune stimulation, and malignant primary disease. The occurrence of and risk factors for malignant neoplasm in long-term survivors must be assessed. OBJECTIVE: To determine the risk and define potential risk factors for new malignant conditions in long-term survivors after marrow transplantation. DESIGN: Retrospective multicenter study. SETTING: Study of the Late Effects Working Party with 45 transplantation centers cooperating in the European Cooperative Group for Blood and Marrow Transplantation. PATIENTS: 1036 consecutive patients who underwent transplantation for leukemia, lymphoma, inborn diseases of the hematopoietic and immune systems, or severe aplastic anemia. Transplantation was done before December 1985, and patients had survived more than 5 years. MEASUREMENTS: Reports on malignant neoplasms were evaluated, and the incidence was compared to that in the general population. Patient age and sex, primary disease and status at transplantation, histocompatibility of the donor, conditioning regimen, type of prophylaxis of graft-versus-host disease, development of acute and chronic graft-versus-host disease, and treatment of chronic graft-versus-host disease were evaluated as variables. RESULTS: Median follow-up since transplantation was 10.7 years (range, 5 to 22.1 years). Malignant neoplasms were seen in 53 patients; the actuarial incidence (+/- SE) was 3.5% +/- 0.6% at 10 years and 12.8% +/- 2.6% at 15 years. The rate of new malignant disease was 3.8-fold higher than that in an age-matched control population (P < 0.001). The most frequent malignant diseases were neoplasms of the skin (14 patients), oral cavity (7 patients), uterus (including cervix) (5 patients), thyroid gland (5 patients), breast (4 patients), and glial tissue (3 patients). Median age of patients and their donors was 21 years. Malignant neoplasms were more frequent in older patients and in patients with chronic graft-versus-host disease. Older patient age and treatment of chronic graft-versus-host disease with cyclosporine were significant risk factors for new malignant neoplasms after bone marrow transplantation. CONCLUSIONS: The spectrum of neoplasms and immunosuppressive treatment with cyclosporine for chronic graft-versus-host disease as dominant risk factors indicate that immunosuppression is the major cause of malignant neoplasms in patients receiving marrow transplants.

Asunto(s)

RESUMEN

Animal experiments have contributed a great deal to our information on effects and risks arising from exposure to radionuclides. This applies, in particular, to alpha-emitting radionuclides where information from man is limited to thorotrast, 224Ra and 226Ra. The late C.W. Mays was the first to suggest that animal data in conjunction with epidemiological data could allow estimates of human risks for radionuclides - predominantly from actinides - where information in man is scarce. The 'International Radiobiology Archives of Long-term Animal Studies' were created through the combined efforts of European, American and Japanese scientists and aim to safeguard the large amount of existing data on long-term animal experiments and make them available for, among others, an improved assessment of risks from alpha-emitting radionuclides. This paper summarizes the structure of the archives and reviews their present status and future plans. It also demonstrates the extensive information available in these archives on alpha-emitting radionuclides which is suitable for further analysis. Also, the structure of the animal archives could - in a slightly modified form - accommodate the epidemiological data available on 224Ra and thorotrast and, thus, facilitate a direct comparison of data from man, dogs and rodents.

Asunto(s)

RESUMEN

Symptoms of wilt, leaf chlorosis, leaf drop, and shoot and plant death were observed in commercial fields of basil (Ocimmum basilicum L.). Disease incidence ranged from 10 to 80% among individual fields. Initial isolations from infected stem tissue were made on water agar amended with streptomycin sulfate. Single-spore isolates transferred onto corn leaf agar were identified as Fusarium oxysporum Schlechtend.:Fr. f. sp. basilicum Dzidzariya. Pathogenicity tests were performed on 10-cm-tall basil plants, cv. Siam Queen, for three Florida isolates and one Massachusetts isolate. An inoculum concentration of 1 × 106 conidia per ml was applied to soil around the roots. Symptoms of wilt, external stem discoloration, and death of basil occurred after 14 days, and F. oxysporum f. sp. basilicum was reisolated from plants inoculated with all four isolates. Controls were disease-free. Identification of the isolates as F. oxysporum f. sp. basilicum was done with a set of DNA primers developed by Pan and Wick (2) for a 0.7-kb DNA fragment unique to this pathogen. This report confirms the existence of F. oxysporum f. sp. basilicum in Florida (1), and identifies this disease as a potential threat to commercial basil production. References: (1) S. A. Alfieri et al. Diseases and Disorders of Plants in Florida. Bull. No. 14. Fla. Dept. Agric. Consumer Serv., 1993. (2) Z. Pan and R. L. Wick. Phytopathology 85:1559, 1995.

RESUMEN

Growth chamber evaluation of several cultivars of basil and related herbs examined in the United States revealed that identical cultivars from different sources did not differ in their reactions to artificial inoculation with Fusarium oxysporum f. sp. basilicum. Cultivars differed in susceptibility to the pathogen: "Spicy globe" miniature was the most susceptible, and lemon basil (Ocimum basilicum var. citriodorum), Origanum majorana, and Thymus vulgaris were rated as not susceptible. Twenty isolates of F. oxysporum, originating from stems of diseased basil plants in Israel, were pathogenic on basil in growth chamber and greenhouse tests. Under artificial inoculation, 2 isolates of F. oxysporum f. sp. basilicum from stems were pathogenic to basil but not to 9 species representing Lamiaceae, Cucurbitaceae, Solanaceae, and Compositae indicating the specificity of the pathogen to basil. These isolates were used for additional resistance tests. Ocimum basilicum var. purpurascens (Exotic) and var. citriodorum were rated as not susceptible to the pathogen under artificial inoculation. Resistant germ plasm was identified in several basil plants of a local variety originally introduced from the United States and reselected at Newe Ya'ar. Seeds were planted in the greenhouse in naturally highly infested soil. Symptomless plants that survived in naturally infested soil were the source for F1 seeds of resistant germ plasm, which was confirmed by artificial inoculations with both isolates of the pathogen. Further selection tests to improve resistance were conducted up to the F4 generation in infested soil in the greenhouse. All individuals of the present genetic line remained symptomless, while all individual plants of the original susceptible cultivar defoliated 3 weeks after planting into infested soil, suggesting that the resistance may be a single, dominant gene. The causal organism was reisolated only from the susceptible plants and not from the symptomless resistant plants through all the experiments.

RESUMEN

Liposomes with mean diameters between 45 and 73 nm have been prepared from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) at pH 8.0; and a new methodology is described which allows one to quantitatively follow the phospholipase D-catalyzed transformation of POPC to 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidic acid and free choline. The method does not require a special sample preparation; it takes advantage of the fact that the chemical shift of the protons of the three methyl groups in free choline differs from the chemical shift of the choline methyl protons in POPC. Measurements have been carried out under different experimental configurations and they have been paralleled by electron and light microscopy studies, partially using a fluorescently labeled phospholipid. It has been found that for a fixed concentration of the Ca2+-independent phospholipase D from Streptomyces sp. AA 586 the initial velocity and the reaction yields depend on the size of the vesicles. The smaller the vesicles, the higher the yields and the lower the initial rates. Furthermore, the size of the liposomes does not change during hydrolysis of the external POPC layer.

Asunto(s)