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  • 1
    Electronic Resource
    Electronic Resource
    Optimization of the Cerenkov sum-frequency generation in proton-exchanged Mg:LiNbO3 channel waveguides (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 65 (1989), S. 1429-1437 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Optical sum-frequency generation has been investigated in channel waveguides produced by proton exchange in Mg-doped as well as standard LiNbO3. Pyrophosphoric acid was used as an exchange media and Ta mask were patterned on z-cut plates by reactive-ion etching to form diffusion apertures ranging in width from 1 to 3 μm running parallel to the y axis. Samples were made by direct immersion in acid held at a temperature of 240 °C for times ranging from 10 to 28 min. End-fire coupling at 1.06 μm revealed that the Cerenkov radiation output at the second harmonic was optimized for the narrowest channel with a diffusion time of 24 min. A coupled throughput of 0.57 mW would produce a Cerenkov second-harmonic radiation mode due to the TM00 fundamental of 0.031 μW for a sample 4 mm in length. Diffusion times differing by 1 min around the optimum time would result in a reduction in harmonic generation efficiency by approximately a factor of 5. Samples pumped at 0.833 μm showed peak efficiency for a correspondingly shorter diffusion time. Severe drift in both fundamental throughput as well as harmonic generation is observed if pump throughput exceeds 2 mW in specimens formed in either Mg-doped or undoped LiNbO3. In addition, diffusion times for optimized nonlinear generation varied from batch to batch. The Cerenkov generation efficiency has been modeled using a step-index approximation for channel waveguides generalized to the z-cut y-propagating orientation used. The nonlinear source polarization at the sum frequency is considered to be due to only d33. Using values for the increase in extraordinary index estimated from fitting mode indices to the step-index approximation, we find optimum second-harmonic generationdue to the TM00 takes place for the mode close to cutoff at either 1.06 or or 0.833 μm. The magnitude of the peak SHG efficiency is found to agree reasonably well with experiment. The variation in guide depth over which the optimum SHG is observed is roughly 0.05 μm. The model predicts this should be larger by a factor of 3. We attribute the discrepancy to the inability of the channel waveguide model to accurately calculate the propagation and decay constants of the pump mode near cutoff. Our effective index measurements further indicate the dispersion in the increase of the extraordinary index (Δne) under the ion-exchange process is essentially equivalent to results published for guides made using benzoic acid when the exchange is performed at 249 °C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.342981
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  • 2
    Electronic Resource
    Electronic Resource
    Erratum: "Optimization of the Cerenkov sum-frequency generation in proton-exchanged Mg:LiNbO3 channel waveguides'' [J. Appl. Phys. 65, 1429 (1989)] (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 2232-2232 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.344498
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  • 3
    Electronic Resource
    Electronic Resource
    Oestradiol Microimplants in the Ventromedial Preoptic Area Inhibit Secretion of Luteinizing Hormone via Dopamine Neurones in Anoestrous Ewes (2001)
    Oxford, UK : Blackwell Science, Ltd
    Journal of neuroendocrinology 13 (2001), S. 0 
    Details
    ISSN: 1365-2826
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Oestradiol exerts a season-specific negative feedback effect on the GnRH/LH neurosecretory system of the Suffolk ewe. This neuroendocrine suppression is mediated in part by dopamine A15 neurones, but these neurones do not possess the oestrogen receptor. Based on indirect evidence, we hypothesized that oestrogen receptor-containing neurones in the ventromedial preoptic area (vmPOA) may be the initial step in a neuronal system whereby oestradiol suppresses GnRH secretion during the non-breeding season. To test this, three experiments were conducted using ovariectomized ewes receiving either empty or oestradiol-containing bilateral microimplants directed at the vmPOA or s.c. subcutaneous oestradiol-containing implants. In the first experiment, LH pulse frequency was measured on days 0, 1, 7 and 14 of treatment during seasonal anoestrus. In vmPOA oestradiol and s.c. oestradiol groups only, LH pulse frequency was suppressed on days 7 and 14, with maximal suppression evident by day 7. In the second experiment, this protocol was repeated during the breeding season, with LH pulses examined on days 0 and 7; LH pulse frequency did not change in any group. The third experiment tested if the effect of vmPOA oestradiol during anoestrus could be overcome by an injection of the dopamine-D2 receptor antagonist (–)-sulpiride. The vmPOA microimplants and s.c. oestradiol implants again suppressed LH pulse frequency and this was reversed by sulpiride in vmPOA oestradiol ewes. We conclude that oestradiol acts on cells in the vmPOA to stimulate a system involving dopamine neurones that inhibits GnRH/LH pulsatility in the anoestrous ewe.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2826.2001.00726.x
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  • 4
    Electronic Resource
    Electronic Resource
    Incidence of second neoplasms in patients with MALT lymphoma: No increase in risk above the background population (1999)
    Springer
    Annals of oncology 10 (1999), S. 317-321 
    Details
    ISSN: 1569-8041
    Keywords: lymphoma ; MALT ; second neoplasm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Lymphomas of mucosa associated lymphoid tissue (MALT) are a special type of extranodal lymphoma, possibly related to chronic antigenic stimulation. Increased cancer susceptibility may also contribute to the development of MALT lymphoma (MALToma). It has been suggested that patients with MALToma have an increased incidence of other malignancies. Patients and methods: We retrospectively reviewed the histology and clinical records of 147 patients with MALToma, including 51 cases of gastric MALToma. The incidence of any second malignancy was confirmed with a provincial registry. The relative rates of cancer, excluding MALToma, were calculated relative to the background population of the same age group and secular year. Results: A total of 41 tumors occurred in 32 patients (21%), including 22 solid tumors. The incidence of solid tumors in the gastric MALToma group was 15%. Seven patients had two or more second malignancies. Cancer occurred before diagnosis of MALToma in 29 cases, concurrent with MALToma in three, and after MALToma in nine. Follow-up of the surviving patients is short (median 17.6 months). The relative rate from birth of a second malignancy was 0.86 in the whole group (90% confidence interval (CI): 0.62–1.16) and 0.95 (90% CI: 0.55–1.54) in the gastric MALToma group. The rates were roughly the same if skin cancers were excluded. Conclusions: The incidence of second cancers in this series is similar to previous reports. However, when compared to an age-matched population followed for the same period of time, MALToma patients do not appear to have a statistically significant increased rate of cancers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008328226599
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  • 5
    Electronic Resource
    Electronic Resource
    Allografting for indolent lymphoid neoplasms (2000)
    Springer
    Annals of oncology 11 (2000), S. 59-61 
    Details
    ISSN: 1569-8041
    Keywords: allogeneic bone marrow transplantation ; indolent lymphoid neoplasms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background:Allogeneic bone marrow transplantation (BMT) has beenused in patients with low-grade lymphoma (LGL) and chronic lymphocyticleukemia (CLL) with the goal of achieving long-term disease-free survival. Patients and methods:Twenty-nine patients with these diagnoses(LGL = 19, CLL = 10) received allogeneic BMT between September 1995 andJanuary 1999. Median age was 42 (range 20–52) years. Twenty-three oftwenty-nine patients (79%) were Ann Arbor or Rai stage IV at the timeof transplant; twenty-four (83%) had never achieved complete remission(CR). Donor source was HLA-matched sibling (20), unrelated (8) and syngeneic(1). Results:Seventeen patients are currently alive, a median of 29months (range 1–85) post-BMT with a median KPS of 90%.Twenty-three of twenty-seven evaluable patients (85%) achieved CRpost-BMT. Six patients had refractory/recurrent disease. Death occurredrelated to transplant complications in eight patients and underlying diseasein four. Overall and event-free survival for the whole group is 51% and44%, respectively. Conclusions:Allogeneic BMT for young patients with advanced stageLGL or CLL is a feasible strategy that can result in achievement of long-termdisease-free survival.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008379605137
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  • 6
    Electronic Resource
    Electronic Resource
    Advanced diffuse large-cell lymphoma treated with 12-week combination chemotherapy: Natural history of relapse after initial complete response and prognostic variables defining outcome after relapse (1997)
    Springer
    Annals of oncology 8 (1997), S. 1125-1132 
    Details
    ISSN: 1569-8041
    Keywords: lymphoma ; relapse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: To define both the natural history of and prognostic factors affecting outcome post relapse from a complete response in advanced stage diffuse large-cell lymphoma. Patients and methods: A total of 468 patients aged 17–74 years received the 12-week duration chemotherapy regimens MACOP-B, VACOP-B and ACOP-12 between 1 April 1981 and 31 December 1995 for advanced stage diffuse large, mixed or immunoblastic lymphoma. Of these 402 entered a complete remission, 97 (24%) of whom subsequently relapsed. Initial staging data, follow-up, and relapse information were analyzed to define the natural history of relapse and also subjected to univariate and multivariate correlation with overall (OS) and failure free survival (FFS). Results: Eleven percent of the relapses were low grade. All other relapses were of intermediate grade with 75% occurring within the first two years, the remainder up until the eleventh year. Median and five-year OS from the time of relapse for intermediate grade relapse were 12 months and 20%; for FFS they were eight months and 18% respectively. Adverse independent factors, for both OS and FFS were: less than one year to relapse, decreasing performance status at relapse, and more than three nodal sites at relapse. Conclusions: Low-grade relapse is not uncommon in patients who initially presented with diffuse large cell lymphoma. As the management of low- and intermediate grade disease is so different biopsy proof of the nature of the relapse is of value. The prognostic factors identified need to be taken into consideration when analyzing results from trials of secondary treatment so as to avoid erroneous conclusions about comparative treatment efficacy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008263602334
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  • 7
    Electronic Resource
    Electronic Resource
    Hepatitis C infection and B-cell non-Hodgkin's lymphoma in British Columbia: A cross-sectional analysis (1999)
    Springer
    Annals of oncology 10 (1999), S. 961-964 
    Details
    ISSN: 1569-8041
    Keywords: Canada ; hepatitic C ; non-Hodgkin's lymphoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objectives: To determine the prevalence of hepatitis C virus (HCV) infection in patients with B-cell non-Hodgkin's lymphoma (NHL) in British Columbia. Design: A cross-sectional analysis. Setting: The British Columbia Cancer Agency (BCCA), a Canadian provincial tertiary oncology referral center. Subjects: Consecutive patients with B-cell NHL registered onto the BCCA lymphoma database in 1996 and part of 1997 and a control group of patients with T-cell NHL registered on the database from 1995 through 1997. Patients with HIV infection were excluded from the analysis. A second control group (n = 1085) consisted of health-care workers tested for HCV infection following a needle-stick injury. Interventions: Stored sera from patients with B-cell NHL (n= 88) and T-cell NHL (n = 37), identified from the database, were tested for the presence of HCV infection with commercially available serologic tests. Main outcome measures: HCV seropositivity in the B-cell lymphoma group compared to the control groups (T-cell NHL and health-care workers). Results: 2.3% of the B-cell NHL group, none of the T-cell NHL group and 1% of the health-care worker control group were positive for HCV infection. These results were not statistically significantly different. Conclusion: Patients in British Columbia with B-cell NHL do not have an increased prevalence of HCV infection. These data suggest that the lymphotrophism of HCV may differ by regional, racial and genotypic variations around the world.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008361311409
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  • 8
    Electronic Resource
    Electronic Resource
    t(11;18)(q21;q21) is the most common translocation in MALT lymphomas (1997)
    Springer
    Annals of oncology 8 (1997), S. 979-985 
    Details
    ISSN: 1569-8041
    Keywords: MALT lymphoma ; t(11;18) translocation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Background: Low grade malignant lymphomas arising from mucosa associated lymphoid tissue (MALT) represent a distinct clinicopathological entity. The cytogenetic findings and molecular genetics of MALT lymphomas remain minimally defined. Cytogenetic studies infrequently constitute part of the diagnostic work-up of MALT lymphomas, most commonly due to small biopsy size and their extranodal localization. Only 28 MALT cases with a clonal karyotype have been published to date. A number of chromosomal abnormalities have been observed with the majority of the cases featuring trisomy of chromosome 3 which is present in up to 78% of the cases. Materials and methods: A total of 116 cases of MALT lymphoma were diagnosed at BCCA between 1988 and 1997. Eleven cases of pathologically confirmed MALT lymphomas were subjected to cytogenetic analysis at the time of the initial evaluation. Eight of 11 cases yielded successful cultures and the presence of a clonal karyotype using standard cytogenetic methodology. In addition, a single case of orbital MALT lymphoma with a clonal karyotype has been obtained through our consultative practice from University of Nebraska Medical Center. These nine cases of MALT lymphoma with a clonal karyotype are the subject of this report. Results and conclusion: In this study we report nine cytogenetically studied MALT lymphomas, three of which feature a novel t(11;18)(q21;q21) translocation which has also been observed in five other MALT cases described in the literature. This recurrent translocation is the most common translocation associated with MALT lymphomas being present in 33% (three of nine) of our cases and 18% (five of 28) of the previously published cases. The results suggest that a potentially important gene located at one of these breakpoints may be involved in the pathogenesis of MALT lymphomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008202303666
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