Reflection across plant cell boundaries in confocal laser scanning microscopy.

The fluorescence patterns of proteins tagged with the green fluorescent protein (GFP) and its derivatives are routinely used in conjunction with confocal laser scanning microscopy to identify their sub-cellular localization in plant cells. GFP-tagged proteins localized to plasmodesmata, the intercellular junctions of plants, are often identified by single or paired punctate labelling across the cell wall. The observation of paired puncta, or 'doublets', across cell boundaries in tissues that have been transformed through biolistic bombardment is unexpected if there is no intercellular movement of the GFP-tagged protein, since bombardment usually leads to the transformation of single, isolated cells. We expressed a putative plasmodesmal protein tagged with GFP by bombarding Allium porrum epidermal cells and assessed the nature of the doublets observed at the cell boundaries. Doublets were formed when fluorescent spots were abutting a cell boundary and were only observable at certain focal planes. Fluorescence emitted from the half of a doublet lying outside the transformed cells was polarized. Optical simulations performed using finite-difference time-domain computations showed a dramatic distortion of the confocal microscope's point spread function when imaging voxels close to the plant cell wall due to refractive index differences between the wall and the cytosol. Consequently, axially and radially out-of-focus light could be detected. A model of this phenomenon suggests how a doublet may form when imaging only a single real fluorescent body in the vicinity of a plant cell wall using confocal microscopy. We suggest, therefore, that the appearance of doublets across cell boundaries is insufficient evidence for plasmodesmal localization due to the effects of the cell wall on the reflection and scattering of light.

Late Season Occurrence of Soybean Rust Caused by Phakopsora pachyrhizi on Soybean in Illinois.

Soybean rust, first reported in the continental United States in Louisiana in 2004 (2), is one of the most important foliar diseases of soybean worldwide. On 10 October 2006, 20 soybean leaflets from 20 plants at physiological maturity were arbitrarily collected in research plots near Glendale, IL at the University of Illinois Dixon Springs Agricultural Center in Pope County and sent by overnight courier. On 11 October, leaflets were examined with a dissecting microscope at the Soybean Disease Laboratory at the National Soybean Research Center, and then at the Plant Disease Clinic, University of Illinois. Tan, angular lesions that were 2 to 4 mm in diameter were observed on the lower leaf surfaces of two of the 20 leaflets. Within these lesions, there was one uredinum on one leaflet and four on the other leaflet exuding hyaline, echinulate urediniospores (20 × 25 µm). On 11 October 2006, these leaflets were sent by overnight courier to the USDA/APHIS/PPQ/NIS Laboratory, Beltsville, MD Plant Disease Clinic for identification by morphological examination and by PCR using primers specific to Phakopsora pachyrhizi (1). Both tests confirmed the presence of P. pachyrhizi. The 18 leaflets that did not have sporulating pustules on 11 October were incubated in the laboratory for 5 days at near 100% relative humidity. Following incubation, nine leaflets were observed to have uredinia exuding urediniospores with a range of 1 to 43 uredinia per leaflet. These results indicate that incubation may be necessary to maximize the potential to observe uredinia exuding urediniospores. To our knowledge, this is the first report of P. pachyrhizi infecting plants in Illinois. References: (1) R. D. Frederick et al. Phytopathology 92:217, 2002. (2) R. W. Schneider et al. Plant Dis. 89:774, 2005.

Isolation and characterization of a hormone-producing cell line from human small cell anaplastic carcinoma of the lung.

A continuous cell culture line was established from a bone marrow metastasis of small cell anaplastic carcinoma of the lung. The cultures were characterized by light and electron microscopy, and an unusual concentric arrangement of cells was observed, both in sectioned material from the patient's tumor and from the cell cultures. The cells had two types of specialized cell junctions and contained secretory-like granules of the type described in neuroendocrine cells. Lactic dehydrogenase isozyme patterns were the same as those observed in normal human serum, and the karyotype revealed the presence of several marker chromosomes. Vasopressin was present in the cells and secreted into the culture medium in the absence of neurophysin, as shown by the immunoperoxidase technique and radioimmunoassay. Oxytocin was also absent from cells.

Combined modality therapy with radiotherapy, chemotherapy, and immunotherapy in limited small-cell carcinoma of the lung: a Phase III cancer and Leukemia Group B Study.

Patients with limited-stage small-cell carcinoma of the lung (SCCL) were randomly assigned to a four-drug chemotherapy program consisting of methotrexate, doxorubicin, cyclophosphamide, and CCNU (MACC) or to a regimen consisting of cyclophosphamide, CCNU, and vincristine alternated with Adriamycin (Adria Laboratories, Columbus, Ohio) and vincristine (CCV/AV). All patients received 4,500 cGy, in a split course, to the primary tumor, mediastinum, and supraclavicular lymph node drainage areas and 3,000 cGy to the whole brain. After four cycles of chemotherapy, patients were randomly assigned to chemotherapy plus methanol extractable residue of BCG (MER-BCG) or no MER-BCG. The complete response frequencies were similar for the two regimens (54% and 48%) as were the median survivals (12.0 and 11.5 months) and the two-year survival rates (15% and 17%). Immunotherapy with MER-BCG did not prolong the time to disease progression or improve survival. Women had a greater chance of achieving a complete remission independent of performance status. There was a complex interaction between sex and the chemotherapy regimens that may have important implications for the design and stratification of future trials in SCCL.

Unusual pulmonary reaction to respiratory therapy in a premature newborn.

The case of an infant with the clinical features of bronchopulmonary dysplasia but with pathologic features unlike those usually associated with this condition is reported. The condition of this infant was probably related to respiratory therapy and may have been a variant of bronchopulmonary dysplasia.

Severe congestive heart failure and cardiomyopathy as a complication of myotonic dystrophy in pregnancy.

The pregnancy of a patient with myotonic dystrophy and heart failure due to cardiac involvement is described. Endomyocardial biopsy was performed at 32 weeks' gestation with echocardiographic guidance to establish the diagnosis. Severe congestive heart failure, refractory to conventional therapy, was encountered. Continuous arteriovenous hemofiltration was used to relieve pulmonary edema before cesarean delivery.

Decreased seroprevalence for Toxoplasma gondii in Seventh Day Adventists in Maryland.

Despite its widespread prevalence, uncertainties remain about the relative contribution of various routes of transmission to the overall rate of infection with Toxoplasma gondii, particularly in developed countries. To explore the hypothesis that meat consumption is an important risk factor for infection, a cross-sectional seroprevalence study was performed on healthy adults in one region in the state of Maryland. The population included Seventh Day Adventists who as a group follow a diet containing no meat, and control community volunteers who were not Seventh Day Adventists. Thirty-one percent of the population had serologic evidence of T. gondii infection. People with T. gondii infection were older (49 versus 42 years old; P < 0.01, by t-test) and less likely to be Seventh Day Adventists (24% versus 50%; P < 0.01, by chi-square test) than people without T. gondii infection. When adjustments were made for age and gender through multiple logistic regression, Seventh Day Adventists had a significantly decreased risk of T. gondii infection (odds ratio = 0.21, 95% confidence interval = 0.09-0.46, P = 0.0001) compared with the controls. While the basis for this effect remains to be determined, one possible protective factor is the general adherence of Seventh Day Adventists to a diet that does not contain meat.

Analysis of Mycobacterium tuberculosis transmission patterns in a homeless shelter outbreak.

SETTING: From July 1997 through May 1998, ten tuberculosis (TB) cases were reported among men in a Syracuse New York homeless shelter for men. OBJECTIVE AND DESIGN: Investigation to determine extent of, and prevent further, transmission of Mycobacterium tuberculosis. RESULTS: Epidemiologic and laboratory evidence suggests that eight of the ten cases were related. Seven cases had isolates with matching six-band IS6110 DNA fingerprints; the isolate from another case had a closely related fingerprint pattern and this case was considered to be caused by a variant of the same strain. Isolates from eight cases had identical spoligotypes. The source case had extensive cavitary disease and stayed at the shelter nightly, while symptomatic, for almost 8 months before diagnosis. A contact investigation was conducted among 257 shelter users and staff, 70% of whom had a positive tuberculin skin test, including 21 with documented skin test conversions. CONCLUSIONS: An outbreak of related TB cases in a high-risk setting was confirmed through the use of IS6110 DNA fingerprinting in conjunction with spoligotyping and epidemiologic evidence. Because of the high rate of infection in the homeless population, routine screening for TB and preventive therapy for eligible persons should be considered in shelters.

Effects of challenge dose on the clinical and immune responses of cattle vaccinated with reduced doses of Brucella abortus strain 19.

Fifty-seven pregnant beef heifers that were unvaccinated or previously vaccinated with Brucella abortus S19, at a dose of either 10(9) or 10(10) colony-forming units (CFU), were challenge-exposed intraconjunctivally with virulent B. abortus S2308 at a dose of 9.4 X 10(6) CFU (Experiment 1) or 5.2 X 10(7) CFU (Experiment 2). In Experiment 1, S19 afforded significant protection (P less than 0.01) against challenge exposure in that 8 of 9 unvaccinated heifers, 1 of 11 vaccinated with 10(9) CFU, and 3 of 10 vaccinated with 10(10) CFU aborted or delivered weak, non-viable calves. In Experiment 2, vaccination did not afford significant protection (P greater than 0.05) in that 9 of 9 unvaccinated heifers, 8 of 10 vaccinated with 10(9) CFU, and 8 of 8 vaccinated with 10(10) CFU aborted. Serologic responses to B. abortus were determined by three standard tests, as well as a quantitative fluorometric immunoassay (FIAX) and an enzyme-linked immunosorbent assay. In Experiment 1, the early serologic response, 0-8 weeks after challenge, appeared greater for controls than for vaccinates, but in Experiment 2, the early response, 0-6 weeks after challenge exposure, appeared greater for vaccinates than for controls. The lymphocyte blast transformation assay, using heat-killed B. abortus as an antigen, was performed sequentially after challenge exposure. In general, mean responses were significantly higher (P less than 0.05) for vaccinated than for non-vaccinated heifers. For individual heifers, an association could not be established between the lymphocyte blast transformation assay and the clinical response to challenge exposure.

Prehistoric parasitism in Tennessee: evidence from the analysis of desiccated fecal material collected from Big Bone Cave, Van Buren County, Tennessee.

Eight samples of desiccated human feces collected from Big Bone Cave (40VB103), Van Buren County, Tennessee, were analyzed to determine the presence of ecto- and endoparasitic infection among the prehistoric population using the cave. Radiocarbon-dated torch material from the cave indicated that it was a locus of human activity 2,177 +/- 145 yr ago. Parasitic species identified were: Ascaris lumbricoides, Enterobius vermicularis, fleas of the tribe Phalacropsyllini, and protozoan cysts. The cysts were identified as Giardia using an indirect immunofluorescent antibody test. The only report of Giardia in a prehistoric context is the identification of cysts in 2 1,800-yr-old paleofecal specimens from a cave in Israel. This is the first report of Giardia from paleofeces in the New World.

Angiocaulus gubernaculatus in the island fox (Urocyon littoralis) from the California Channel Islands and comments on the diagnosis of angiostrongylidae nematodes in canid and mustelid hosts.

Adult nematode parasites were recovered from the heart blood of a deceased island fox (Urocyon littoralis) submitted for necropsy to determine the cause of death. Examination of the recovered nematodes supported the generic diagnosis of Angiocaulus, a parasite in Angiostrongylidae found in domestic and wild canids and mustelids. Specific diagnosis of the worms from the island fox as Angiocaulus gubernaculatus is based on the morphology of the dorsal ray in the copulatory bursa of the male worm and its comparison with published descriptions of Angiocaulus raillieti and A. gubernaculatus. Although A. gubernaculatus has been typically associated with mustelid hosts, its occurrence in the island fox indicates that the host distribution for the parasite may not be as restricted as previously believed.

Archeological evidence of parasitic infection from the 19th century company town of Fayette, Michigan.

Archeological deposits from the 19th century company town of Fayette, Michigan were analyzed for evidence of endoparasitic infection in the human population residing in the town between 1867 and 1891. Three privies were associated with upper-income and middle-income neighborhoods; 2 household refuse disposal areas were found in a predominately lower-income immigrant working class neighborhood. Sediment samples from 2 privies associated with dwellings in the middle-income neighborhood were positive for eggs of the human whipworm Trichuris trichiura. The parasite was probably also present among residents of the lower income neighborhood, but the shallow nature of the refuse deposits in that locality precluded preservation of the eggs. Contemporary epidemiologic studies of helminth infections support the belief that T. trichiura may have been a common parasite of 19th century school-age children given the natural inclination of young children to defecate indiscriminately, play freely in the dirt, and eat without washing their hands.

Fine-needle biopsy: comparison of cellular yield with and without aspiration.

Fine-needle biopsies with and without aspiration were performed on 103 lesions, and the cellular yields obtained by the two techniques were compared. A scoring system was devised by which the amount of material obtained in each needle stick was estimated. The mean score/stick for fine-needle biopsy with aspiration was 2.7; for biopsy without aspiration, it was 2.9. The results of this study indicate that there is no significant difference in the amount of cellular material obtained by the two techniques. It is concluded that needle biopsy without aspiration may be performed routinely with good results.

Role of testicular fine-needle aspiration biopsy in the evaluation of male infertility: cytologic and histologic correlation.

A series of testicular fine-needle aspiration biopsy specimens from 272 infertile men with azoospermia were reviewed and categorized according to morphologic patterns. These included active spermatogenesis, 14 (5%); hypospermatogenesis, 106 (39%); Sertoli cells only, 70 (26%); atrophic pattern, 52 (19%); and maturation arrest, 1 (0.36%). In 29 cases (11%) the amount of material was insufficient for evaluation. The histologic and cytologic findings in 52 cases showing spermatogenesis correlated very well in 52 cases for which open testicular biopsy specimens were also available. These findings indicate that fine-needle aspiration biopsy of the testis is a reliable and useful technique for the investigation of patients with azospermia.

Prevalence of Dirofilaria immitis and Dipetalonema reconditum infection in dogs: 805 cases (1980-1989).

Clinical records of 6,977 dogs examined at the small animal clinic of the University of Tennessee College of Veterinary Medicine from January 1980 through December 1989 were analyzed to determine the prevalence and changing frequency of Dirofilaria immitis and Dipetalonema reconditum infection. Using the Knott's test on these dogs, 805 (11.54%) tested positive for microfilariae, with D immitis in 430 dogs (6.16%), and Dip reconditum in 375 dogs (5.37%). Statistical analysis confirmed that the prevalence of D immitis and that of Dip reconditum were essentially equal in the population of dogs included in this study. There was a slight decrease in the prevalence of D immitis over the 10 years examined, but the prevalence of Dip reconditum remained constant. The results were not affected by year-to-year variability in the number of examinations performed. On the basis of our findings, in eastern Tennessee, those veterinarians who diagnose heartworm infection by the presence of microfilariae without differentiating the species involved, risk misdiagnosing 50% of the cases. If the patterns of prevalence seen in recent years continue, the chances of error may actually increase.

Comparison of the efficacies of three heartworm preventives against experimentally induced infections with Ancylostoma caninum and Toxocara canis in pups.

Forty 11- to 12-week-old helminth-naive Beagles were categorized by sex and weight and randomly assigned to 4 treatment groups (group 1, ivermectin/pyrantel pamoate; group 2, milbemycin oxime; group 3, untreated control; group 4, diethylcarbamazine/oxibendazole). Each pup was inoculated PO with approximately 100 infective Ancylostoma caninum larvae and 100 larvated Toxocara canis eggs on day 0, and repeatedly at 7-day intervals thereafter until day 56. Administration of anthelmintics also began on day 0, and subsequent treatments were administered according to label recommendations at 30-day intervals (groups 1 and 2) or daily (group 4) for a period of 90 consecutive days. Body weight and A caninum and T canis fecal egg counts were measured at weekly intervals, and clinical observations of health status were conducted twice daily. Pups were euthanatized on day 90, and total gastrointestinal worm burdens were determined. Compared with mean A caninum egg counts of group-3 control pups, egg counts in group-1 pups were significantly (P < or = 0.0001) lower on every sampling days 35, 42, 49, 63, 70, 77, and 84, and were consistently the highest of all treated groups, and egg counts of group-4 pups were significantly (P < or = 0.0001) lower on every sampling date from day 14 to day 90, and were consistently the lowest of all treated groups. Compared with mean A caninum egg counts of group-3 pups, egg counts in group-1 and group-2 pups were lower by 97.8 and 90.8%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute effects of sucralfate aspiration: clinical and laboratory observations.

STUDY OBJECTIVE: To assess the complications associated with the aspiration of sucralfate. DESIGN: Clinical (case report) and bench observations. SETTING: Inpatient intensive care unit and experimental animal laboratory. SUBJECTS: The case of a critically ill patient who aspirated sucralfate is presented. Fifteen Sprague-Dawley rats served as experimental animals to investigate the acute histologic effects of large-volume aspiration of sucralfate. INTERVENTIONS: The patient underwent emergent intubation to relieve acute upper airway obstruction. All the animals were anesthetized and had tracheostomies performed. The experimental groups had acidic intratracheal injections of 2 ml/kg of a nonparticulate liquid (pH, 2.3; n = 6) or a sucralfate aspirate (1 ml/kg of a 5% sucralfate suspension of pH 3.6, followed by 1 ml/kg 0.1 of normal hydrochloric acid of pH 1.0; n = 4). Four hours after simulated aspiration, the rats were sacrificed and their lungs removed for histologic examination by light microscopy. MEASUREMENTS AND MAIN RESULTS: Differences were noted in histopathologic injury in the experimental groups compared to the control group using a numeric scoring scale. Nonparticulate acidic liquid aspiration caused a significant increase (p < 0.05) in inflammation. Sucralfate caused a significant increase (p < 0.05) in lung hemorrhage. A nonsignificant trend was seen with simulated sucralfate aspiration for edema and inflammation. No long-term sequelae were attributed to the clinical aspiration episode. CONCLUSIONS: Acute complications associated with aspiration of sucralfate have been identified. In the laboratory setting, simulated aspiration of sucralfate led to acute lung injury.

The Kety-Schmidt technique for quantitative perfusion and oxygen metabolism measurements in the MR imaging environment.

SUMMARY: The Kety-Schmidt technique provides quantitative measurement of whole-brain CBF. CBF is measured as the area between the arterial and venous washout curves of a diffusible tracer. Oxygen extraction and metabolism may be calculated from arterial and venous samples. In this report, we present a method for performing these measurements in an MR imaging environment. This technique could be useful for validation of MR imaging methods of hemodynamic and metabolic measurements in humans.

Effects of rainfall, host demography, and musth on strongyle fecal egg counts in African elephants (Loxodonta africana) in Namibia.

Wild African elephants (Loxodonta africana) are commonly infected with intestinal strongyle parasites. Our objective was to determine baseline fecal strongyle egg counts for elephants in the northeast region of Etosha National Park, Namibia and determine if these numbers were affected by annual rainfall, elephant demography (age of individuals and composition of groups), and hormonal state of males. We found that matriarchal family group members have significantly higher fecal egg counts than male elephants (bulls). Among family group members, strongyle egg counts increased with age, whereas among bulls, strongyle egg counts decreased with age. Years of higher rainfall were correlated with decreased numbers of strongyle eggs among bulls. Finally, bulls were not affected by their physiologic (hormonal) status (musth vs. nonmusth). These results suggest that infection by strongyle parasites in Namibian African elephants is a dynamic process affected by intrinsic and extrinsic factors including host demography and rainfall.

Actinic cheilitis in dental practice.

Actinic cheilitis is a potentially premalignant condition involving predominantly the vermilion of the lower lip. The aim of the current paper was to review the clinical presentation of actinic cheilitis and demonstrate the development of management plans using a series of cases. These are designed to provide immediate treatment where required but also to address the medium and long-term requirements of the patient. The authors suggest that the clinical examination of lips and the assessment of actinic cheilitis and other lip pathology become a regular part of the routine soft tissue examination undertaken as a part of the periodic examination of dental patients. Early recognition of actinic cheilitis can allow the development of strategies for individual patients that prevent progression. These are based on past sun exposure, future lifestyle changes and the daily use of emollient sunscreens, broad-brimmed hats and avoidance of sun exposure during the middle of the day. This is a service that is not undertaken as a matter of routine in general medical practice as patients are not seen with the regularity of dental patients and generally not under the ideal examination conditions available in the dental surgery.