Search Results - (Author, Cooperation:J. A. Nelson)

2011-05-13

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

AIDS Vaccines/immunology ; Animals ; CD4-Positive T-Lymphocytes/immunology ; CD8-Positive T-Lymphocytes/immunology ; Cytomegalovirus/genetics ; DNA, Viral/analysis ; Genetic Vectors/genetics ; Immunity, Mucosal/immunology ; Immunologic Memory/*immunology ; Macaca mulatta/blood/immunology/virology ; Male ; RNA, Viral/analysis ; SAIDS Vaccines/genetics/*immunology ; Simian Acquired Immunodeficiency Syndrome/blood/*immunology/*prevention & ; control/virology ; Simian Immunodeficiency Virus/growth & development/*immunology/isolation & ; purification/*pathogenicity ; T-Lymphocytes/*immunology ; Time Factors ; Vaccines, DNA/genetics/immunology ; Viral Load ; Virus Replication

2013-09-13

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Cytomegalovirus/genetics/immunology ; Female ; Macaca mulatta ; Male ; Molecular Sequence Data ; SAIDS Vaccines/*immunology ; Simian Acquired Immunodeficiency Syndrome/*prevention & control/virology ; Simian Immunodeficiency Virus/*immunology ; Time Factors ; Vaccines, Attenuated/immunology ; Viral Load ; Virus Replication/physiology

2016-01-23

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Antigen Presentation ; Antigenic Variation ; CD8-Positive T-Lymphocytes/*immunology ; Cytomegalovirus/genetics/*immunology ; Epitopes, T-Lymphocyte/chemistry/*immunology ; Genetic Vectors/genetics/immunology ; Histocompatibility Antigens Class I/chemistry/*immunology ; Host-Pathogen Interactions/immunology ; Immune Evasion ; Killer Cells, Natural/immunology ; Macaca mulatta ; Protein Structure, Secondary ; Simian Immunodeficiency Virus/*immunology ; Vaccination

2013-05-25

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; CD8-Positive T-Lymphocytes/*immunology ; Cytokines/immunology ; Cytomegalovirus/genetics/*immunology ; Epitopes, T-Lymphocyte/*immunology ; Female ; Genetic Vectors/genetics/*immunology ; Histocompatibility Antigens Class II/immunology ; Humans ; Macaca mulatta ; Male ; Membrane Glycoproteins/genetics ; SAIDS Vaccines/administration & dosage/*immunology ; Viral Envelope Proteins/genetics

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

This study tests whether or not post-exercise oxygen consumption rates (Mo2) in fish are dependent upon how exhaustion is induced. A group of eight Atlantic cod (Gadus morhua) were each exercised using (1) a critical swimming speed (Ucrit) protocol, (2) an exercise protocol designed to measure anaerobic capacity of fish (Uburst), and (3) a protocol in which the fish were chased to exhaustion manually. Mo2 was measured for a 2-h period following exhaustion induced by all three exercise regimes (Ucrit, Uburst and chase). Post-exercise Mo2 following exhaustion from the Uburst and chase protocols were significantly higher than post-exercise Mo2 following the Ucrit protocol. Each fish during the Ucrit protocol exhibited maximal Mo2 during exercise rather than during recovery, yet 75% of the fish during Ubrust recovery and 100% during chase recovery exhibited Mo2 higher than that measured during Ucrit exercise. These results, as well as the large interindividual variations in Mo2 among the eight fish, show that post-exhaustion Mo2 is specific to the exercise regime employed, thus, investigators must exercise caution when combining results from different exercise protocols and/or individuals.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The extinction of piscine populations in waters acidified by atmospheric fallout of pollutants and runoff from coal strip mines usually occurs through recruitment failure. To determine mechanisms of recruitment failure, several physiological parameters of developing rainbow trout were monitored while fish were exposed to conditions of low pH and varied calcium ion concentrations. Cardiac rate, ossification, growth, tissue calcium concentrations, protein maturation, hatching, and mortality were examined. Results indicate a decreased cardiac rate, decreased rate of ossification, slower growth, less pigmentation, delayed hatching and increased mortality under conditions of low pH. Cardiac rate, hatching and mortality varied with the external calcium concentration.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Continuous monitoring of heart rate, breathing episodes and blood pressure showed that the cardio-respiratory response of carp exposed to nitrite (water concentration, 1 mmol l−1) changes with length of exposure. The animals developed a severe methaemoglobinaemia over the first 24 h of nitrite exposure. The minor changes in plasma HCO3− and lactate concentration, suggest that the observed hyperventilatory response was sufficient to maintain aerobic metabolism throughout most of the body during this time. During the second 24-h period, the rate of breathing increased further and short periods of bradycardia and hypotension were seen. Over this latter period, the animals increased their use of anaerobic metabolism as illustrated by the mean 48 h blood lactate concentration of 4.8mmol 1−1, a greater than 10-fold increase over pre-exposure values. The increase in blood lactate was accompanied by the predicted metabolic acidosis, however, an alkalosis of respiratory origin and buffering combined to keep the plasma pH absolutely stable throughout the study. This study shows that as the blood oxygen supply is reduced through the development of methaemoglobinaemia, cardio-respiratory compensation by the carp is probably adequate to maintain tissue oxygenation for short periods of nitrite exposure. However, as nitrite exposure proceeds past 24 h, the animals progress into a positive feedback cycle where the high cost of additional ventilation rapidly accelerates their oxygen deficit which cannot be repaid, because 〈25% of their haemoglobin is available for oxygen binding. Additionally, our data demonstrate a circadian rhythm of physiological response to nitrite and contradict the hypothesis that catecholamine release promotes CO2 retention in water breathing animals.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Atlantic cod (Gadus morhua) were forced to swim in a swim tunnel respirometer until fatigued; oxygen consumption rate (ṀO2) was measured during swimming at incremental speeds until the fish was exhausted and during recovery from exhaustion. Maximal oxygen consumption (ṀO2max) occurred during maximal activity as has been found for other fish species, but at odds with the current paradigm for Atlantic cod. Earlier experiments had drawn the conclusion that ṀO2max in Atlantic cod occurs during recovery from exhaustive exercise. We found no support for this paradigm in our experiments and we propose that the respiratory physiology of Atlantic cod is not unlike that of other fishes.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Fresh gut contents of the wood-eating loricariid Panaque and a generalized loricariid Liposarcus sp. had enzymatic activity directed against both cellulose and hemicellulose. Aerobic cultures made from the guts of Panaque exhibited growth on a minimal salts medium containing only crystalline cellulose as a carbon source as well as on a variety of other substrates containing carbon polymers found in wood. Anaerobic cultures made from Panaque guts only grew with glucose as a carbon source. Cultures of whole gut contents grown on a yeast extract basal salts medium had significant cellulolytic activity. However, no culture of individual microbes had significant cellulolytic activity, suggesting that any cellulose breakdown which occurs in loricariid guts is by a consortium of micro-organisms. A variety of aerobes, microaerophiles and facultative anaerobes were found in the guts of Panaque; several of these bacteria appear to be new species.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The questions of whether herbivorous loricariid catfishes are hypometabolic or reduce metabolic demand in response to poor dietary quantity and quality were addressed by comparing resting routine metabolic rates in the presence and absence of different fibre content diets for three loricariid species. Metabolic rates of the three species scaled inter-specifically as body mass0·736, similar to most other vertebrates. Metabolic rates did not vary with diet quality for two species; one Panaque species had a significantly lower metabolic rate when fed only wood. Comparisons with the literature led to the conclusions that loricariids in general and Panaque in particular do not have unusually low metabolic rates for quiescent catfishes of their size.

Electronic Resource

1432-0533

Encephalitis ; AIDS ; Human immunodeficiency virus ; Papovavirus ; In situ hybridization

Springer Online Journal Archives 1860-2000

Medicine

Summary Of the 93 acquired immune deficiency syndrome (AIDS) patients autopsied between 1983 and 1986, 27 had evidence of viral encephalitis of which 3 had progressive multifocal leukoencephalopathy (PML), confirmed by electron microscopy. Using in situ hybridization with biotinylated JC virus probes, paraffin sections from the brains of these 27 patients were examined. JC virus was found only in those patients with histologically proven PML, while no evidence of JC virus was detected in the brains of the other 24 AIDS patients despite the presence of white matter pathology. Brain biopsies of the PML patients demonstrated human immunodeficiency virus (HIV)-infected macrophages infiltrating regions of demyelination. When the patients died (2 to 6 months after diagnosis of PML), many more macrophages contained HIV antigens and some had fused to form multinucleated giant cells. These findings suggest that in AIDS patients, papovaviruses not only cause damage by directly infecting oligodendroglia but causes additional damage by eliciting the ingress of macrophages latently infected with HIV. As was seen with other infections (e.g., cytomegalovirus) of the CNS this might be a general mechanism of HIV entry into the brain.

Electronic Resource

1432-0843

Key words Oocytes ; Xenopus laevis ; Transport ; P-glycoprotein ; Renal ; Deoxytubercidin ; Vinblastine ; mRNA ; Translation ; Nucleoside

Springer Online Journal Archives 1860-2000

Medicine

Abstract  The hypothesis that P-glycoprotein (P-gp) mediates the renal secretion of organic cations was tested by functional expression of mRNAs in the Xenopus laevis oocyte system. Efflux of 2′-deoxytubercidin (dTub), a substrate for the renal organic cation transporter (OCT) but not for P-gp, was enhanced by injection of renal mRNA but not by injection of mRNA from P-gp-overexpressing cells (MDCK cells transduced with the cDNA for human MDR1). The functional capacity of the MDCK-MDR mRNA was established by its ability to reduce the steady-state uptake of a classical P-gp substrate, vinblastine. Thus, these data indicate OCT and P-gp to be distinct entities. The Xenopus oocyte system provides a functional approach to further characterize the OCT.

Electronic Resource

1432-0843

Key words Natural killer ; Chronic lymphocytic leukemia ; Fludarabine

Springer Online Journal Archives 1860-2000

Medicine

Abstract  Fludarabine, the 5′-monophosphate of 9-β-D-arabinofuranosyl-2-fluoroadenine (FaraAMP), is effective in the treatment of chronic lymphocytic leukemia (CLL) and has been demonstrated to increase natural killer (NK) cell lytic activity (NKa) in humans and mice. To determine the effect of FaraAMP on NK cells in CLL, we analyzed NKa toward K562 targets after in vitro incubation with FaraAMP and after in vivo exposure to fludarabine. Pretreatment analysis of peripheral blood from 12 CLL patients (9 untreated) revealed: median number of NK cells 500/μl (range 290–1160); median NKa lytic unit30/106 cells (range 5–80). These results were similar to those from healthy adult donors. After exposure to 3, 30, or 300 μM FaraAMP, the median maximum stimulation index (NKa FaraAMP/NKa) was 1.2 (range 0.9–1.5), within the range observed in normal adults. FaraA also stimulated NKa in vitro toward autologous CLL cells in two of five patients as measured by a dye-exclusion assay. In three patients following three or more treatment courses of fludarabine (30 mg/m2 per day for 5 days) the NK cell number and NKa were maintained near pretreatment values. Phenotypic analysis of the peripheral mononuclear cells in 34 consecutive CLL patients revealed a marked reduction in CD5/CD20 and CD4 cell numbers after three courses of fludarabine with less effect on CD8 and CD56 cells. These results indicate that fludarabine spares NK cells and may stimulate NKa in some CLL patients.

Electronic Resource

1439-6327

Key words Altitude training ; Hypobaric hypoxia ; Creatine kinase activity ; Cortisol ; Triathletes

Springer Online Journal Archives 1860-2000

Medicine

Abstract In this investigation we evaluated the effect of a 5-week training program at 1860 m on serum creatine kinase (CK) activity and serum cortisol concentration in national-caliber triathletes for the purpose of monitoring the response to training in a hypobaric hypoxic environment. Subjects included 16 junior-level female (n = 8) and male (n = 8) triathletes who were training for the International Triathlon Union (ITU) World Championships. After an initial acclimatization period, training intensity and/or volume were increased progressively during the 5-week altitude training camp. Resting venous blood samples were drawn at 0700 hours following a 12-h overnight fast and were analyzed for serum CK activity and serum cortisol concentration. Subjects were evaluated before [7–10 days pre-altitude (SL 1)] and after [7–10 days post-altitude (SL 2)] the 5-week training camp at 1860 m. At altitude, subjects were evaluated within 24–36 h after arrival (ALT 1), 7 days after arrival (ALT 2), 18 days after arrival (ALT 3), and 24–36 h prior to leaving the altitude training camp (ALT 4). A repeated-measures analysis of variance was used to evaluate differences over time from SL 1 to SL 2. Compared to SL 1, serum CK activity increased approximately threefold (P 〈 0.05) within the initial 24–36 h at altitude (ALT 1), and increased by an additional 70% (P 〈 0.05) after the 1st week of altitude training (ALT 2). Serum CK activity remained significantly elevated over the duration of the experimental period compared to pre-altitude baseline levels. Serum cortisol concentration was increased (P 〈 0.05) at the end of the 5-week altitude training period (ALT 4) relative to SL 1, ALT 1 and ALT 3. These data suggest that: (1) the initial increase in serum CK activity observed in the first 24–36 h at altitude was due primarily to acute altitude exposure and was independent of increased training intensity and/or training volume, (2) the subsequent increases in serum CK activity observed over the duration of the 5-week altitude camp were probably due to the combined effects of altitude exposure and increased training load, and (3) the increase in serum cortisol concentration observed at the end of the altitude training camp reflects the additive effect of 5 weeks of altitude exposure in combination with a progressively increased training intensity and/or volume.

Electronic Resource

1573-2568

Springer Online Journal Archives 1860-2000

Medicine

Abstract Suture granulomas can occur after gastric surgery with nonabsorbable suture material. They are usually an asymptomatic, incidental finding on post-surgical x-ray studies, but have to be recognized because their radiological appearance may mimic gastric neoplasms and therefore may lead to unnecessary reoperations. Four cases of suture granulomas are presented, their diagnositc criteria outlined, and a plea is made for the use of a new completely absorbable suture material which could eliminate the occurrence of suture granulomas as well as the other known complications related to nonabsorbable sutures, such as suture-line ulcers, abscesses, and adhesions.

Electronic Resource

1435-4373

Springer Online Journal Archives 1860-2000

Medicine

Abstract In spring 1993,Ixodes ricinus ticks were collected from six regions of Slovenia to determine their overall rate of infection withBorrelia burgdorferi sensu lato and to assess the frequency of individual species in these tick populations. Ticks were dissected and midgut tissue inoculated into modified Barbour-Stoenner-Kelly (BSK II) medium.Borrelia isolates were differentiated into separate species using species-specific polymerase chain reaction (PCR) primers and by large restriction fragment pattern (LRFP) analysis. Infected ticks were found in all six regions surveyed. Spirochaetes were isolated from 69 of 363 ticks (19 %): the isolation rate from adult female ticks was 35 % (23/66 ticks cultured), from adult male ticks 22 % (20/91), and from nymphal ticks 13 % (26/206). Determination of the species of 60 isolates revealed that 32 wereBorrelia afzelii (53 %), 20 wereBorrelia garinii (33 %), and 8 wereBorrelia burgdorferi sensu stricto (13 %). In the Ljubljana regionBorrelia afzelii andBorrelia garinii predominated (43 % and 40 %, respectively), whereasBorrelia burgdorferi sensu stricto constituted only 17 % of isolates. In three other regions of the countryBorrelia afzeliiwas isolated exclusively, although the number of isolates investigated was small. This study demonstrates the presence of all three European species ofBorrelia burgdorferi sensu lato within the Slovenian tick population and also within a geographic area of less than 100 m2.

Electronic Resource

1435-4373

Springer Online Journal Archives 1860-2000

Medicine

Abstract One hundred twenty-nine Slovenian isolates ofBorrelia burgdorferi sensu lato derived from patients (69 strains) orIxodes ricinus ticks (60 strains) were characterized. All of the strains were first- or second-passage isolates obtained in 1992 and 1993 from the same endemic region. The techniques used for the molecular analysis of strains included species-specific polymerase chain reaction (PCR) typing, and pulsed-field gel electrophoretic separation of undigested andMlul-digested genomic DNA. Isolates were identified to the species level by large restriction fragment pattern (LRFP) analysis and the results compared with the species-specific PCR result. Fifty-two patient isolates (75%) were typed asBorrelia afzelii (LRFP MLa1), 6 (9%) asBorrelia garinii (LRFPs MLg1–4), and 11 (16%) asBorrelia burgdorferi sensu stricto. The latter included 9 isolates (13%) with a new LRFP that is not typical ofBorrelia burgdorferi sensu stricto and for which the designation MLx is suggested. In contrast, only 32 of 60 (53%) tick isolates were typed asBorrelia afzelii, while 20 strains (33%) were typed asBorrelia garinii and 8 strains (13%) asBorrelia burgdorferi sensu stricto. Three new LRFPs were found among theBorrelia garinii (MLg5 and 6) andBorrelia burgdorferi sensu stricto (MLb15) tick isolates. Large restriction fragment pattern analysis identified new groups ofBorrelia burgdorferi sensu lato and revealed an apparent difference in the isolation frequency of different species from patients and ticks in the same endemic region.

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