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Biomedical subjects

J Curtis

Publications and source records attributed to J Curtis.

At least 37 records · Page 2Linked to original sources
PubMed2001

Superoxide dismutase and catalase do not affect the pulmonary hypertensive response to group B streptococcus in the lamb.

The purpose of this study was to determine whether treatment with conjugated antioxidant enzymes could attenuate or abolish pulmonary hypertension induced by group B streptococcus (GBS). Lambs, 3-7 d old, were anesthetized and ventilated. Intravascular catheters were placed in the left ventricle, descending aorta, right atrium, and pulmonary artery for continuous monitoring of intravascular pressures. Cardiac output was measured with radiolabeled microspheres. Measurements were obtained at baseline and 15 and 60 min into a 60-min GBS infusion, and 60 min after GBS was stopped. Blood gas values were held constant and PaO(2) was maintained >100 mm Hg. The control group received saline vehicle only (n = 6), the GBS group received GBS infusion only (n = 9), the enzymes (ENZ) group received polyethylene glycol-superoxide dismutase (PEG-SOD) and polyethylene glycol-catalase (PEG-CAT) treatment only (n = 6), and the ENZ+GBS group received PEG-SOD and PEG-CAT then GBS (n = 9). Plasma samples were obtained to confirm increased superoxide dismutase and catalase activities in the groups receiving enzymes. Compared with baseline, pulmonary vascular resistance increased by 119% and 101% at 15 min and 87% and 81% at 60 min in the GBS and ENZ+GBS groups, respectively. Sixty minutes after the termination of the GBS infusion, PVR returned to baseline in the GBS group but did not in the ENZ+GBS group. Enzyme infusions resulted in at least a ninefold increase in plasma enzyme activities. As opposed to previously published data from endotoxin models, PEG-CAT and PEG-SOD were ineffective in altering the GBS-induced pulmonary hypertensive response in this model. This suggests that acute administration of antioxidant enzymes may not be effective in ameliorating GBS-induced pulmonary hypertension.

Animals↗
PubMed2001

Thrombosed double inferior vena cava mimicking paraaortic lymphadenopathy.

A case is presented of thrombosis of an anomalous left-sided duplication of the inferior vena cava misinterpreted on CT as lymphadenopathy or other retroperitoneal mass. Recognition of this anomaly is important in reaching the correct diagnosis in such cases. The diagnosis by imaging methods is described as well as their pitfalls.

Aged↗
PubMed2000

Schistosome population genetic structure: when clumping worms is not just splitting hairs.

Schistosomiasis is a major public health problem, affecting over 200 million people worldwide. Although Schistosoma mansoni has been studied rigorously in an attempt to provide a vaccine based on a number of candidate antigens, there has been a lack of complementary effort to determine the range and distribution of variation in representative molecules throughout natural populations. Here, Jason Curtis and Dennis Minchella highlight current (and suggest future) research efforts aimed at assessing genetic variation in schistosome populations, and call for a more robust consideration of schistosome population genetics.

Animals↗
PubMed2000

Mice unresponsive to GM-CSF are unexpectedly resistant to cutaneous Leishmania major infection.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to play a protective role in leishmanial infection. Mice with a null mutation in the gene for the beta common (beta c) chain of the receptors for GM-CSF, interleukin(IL)-3 and IL-5 (beta c-null mice) display normal steady state hemopoiesis and develop lung disease similar to the human condition, alveolar proteinosis, due to a lack of signaling by GM-CSF. We therefore expected to observe a heightened sensitivity to Leishmania major in the beta c-null mice. Surprisingly, the beta c-null mice were more resistant to cutaneous infection than wild-type (wt) mice. Upon intradermal injection of L. major promastigotes, fewer beta c-null mice developed cutaneous lesions than wt mice and these lesions were smaller and healed more rapidly than in wt mice. This resistance to disease was associated with a reduced percentage of in vitro infected beta c-null macrophages. Macrophages from beta c-null mice displayed a more activated phenotype and produced increased amounts of nitric oxide following infection with L. major, both in vivo and in vitro. Paradoxically, however, the parasite burden in the draining lymph nodes was similar in both beta c-null and wt mice, suggesting that at least a subpopulation of cells was susceptible to the parasite. The mechanism preventing normal lesion development remains to be elucidated.

Animals↗
PubMed2000

A reply

Curtis, J. and Lewis-Jones, H. (2000). Clinical Radiology55, 984-985. Copyright 2000 The Royal College of Radiologists.

Journal Article↗
PubMed2000

The radiological appearances of tuberous sclerosis.

Tuberous sclerosis is an autosomal dominant disorder often associated with a chromosome 9 abnormality, although up to 60% of cases occur spontaneously. The incidence of the disorder is between 1/100,000 and 1/10,000, and it leads to multiple organ and skeletal abnormalities. The classical triad of epilepsy, mental retardation and adenoma sebaceum defines the syndrome clinically. Other cutaneous associations include shagreen patches, ash leaf-shaped areas of depigmentation, subungual fibromas and café-au-lait spots. This review describes the commoner radiological manifestations of the syndrome, and briefly mentions the rarer associations that have been reported to date.

Echocardiography↗
PubMed2000

A reply.

Explore the source record for details and available documents.

Cervical Vertebrae↗
PubMed1999

Sending signals from the synapse to the nucleus: possible roles for CaMK, Ras/ERK, and SAPK pathways in the regulation of synaptic plasticity and neuronal growth.

The ability to learn and form memories depends on specific patterns of synaptic activity and is in part transcription dependent. However, the signal transduction pathways that connect signals generated at synapses with transcriptional responses in the nucleus are not well understood. In the present report, we discuss three signal transduction pathways: the Ca(2+)/calmodulin-dependent kinase (CaMK) pathway, the Ras/ERK pathway, and the SAPK pathways that might function to couple synaptic activity to long-term adaptive responses, in part through the regulation of new gene expression. Evidence suggests that these pathways become activated in response to stimuli that regulate synaptic function such as the influx of extracellular Ca(2+) and certain neurotrophin growth factors such as brain-derived neurotrophic factor. Once activated, the CaMK, Ras/ERK, and SAPK pathways lead to the phosphorylation and activation of transcription factors in the nucleus such as the cyclic AMP response element binding protein (CREB). Genes regulated by CREB or other transcription factor targets of the CaMK, Ras/ERK, and SAPK pathways could mediate important adaptive responses to changes in synaptic activity such as changes in synaptic strength and the regulation of neuronal survival and death.

Animals↗
PubMed1999

Secondary acute myeloid leukemia 4 years after the diagnosis of hairy cell leukemia: case report and review of the literature.

A 49-year-old man diagnosed with hairy cell leukemia (HCL) achieved a complete remission lasting 4 years after treatment with cladrabine and subsequently developed acute myeloid leukemia. Although a wide variety of second malignancies have been noted in HCL with an incidence of 8.7%, acute myeloid leukemia (AML) has been reported only once previously in a splenectomized patient who had been treated with alpha interferon.

Acute Disease↗
PubMed1999

Leishmania major proteophosphoglycan is expressed by amastigotes and has an immunomodulatory effect on macrophage function.

Proteophosphoglycan (PPG) is a newly described mucin-like glycoprotein found on the surface of Leishmania major promastigotes and secreted in the culture supernatant. We show here that antigenically similar PPGs are present in several Leishmania species. PPG could also be detected on the surface of amastigotes and in small, parasite-free vesicles in infected macrophages. Because of the similarity of its carbohydrate chains to lipophosphoglycan, a parasite receptor for host macrophages, PPG was tested for binding to macrophages. PPG bound to macrophages and was internalized in a time-dependent manner. PPG inhibited the production of tumor necrosis factor-alpha and synergized with interferon-gamma to stimulate the production of nitric oxide by macrophages. PPG may contribute to the binding of Leishmania to host cells and may play a role in modulating the biology of the infected macrophage at the early stage of infection.

Animals↗
PubMed1999

Fire fatalities in older people.

OBJECTIVE: To compare the epidemiology of fire-related fatalities among older, middle-aged, and young people. DESIGN: Retrospective case series. SETTING: Alabama, 1992-1997. PARTICIPANTS: All persons fatally injured in fire-related incidents in the state of Alabama from 1992 to 1997. MEASUREMENTS: The State Fire Marshal's Office provided both demographic and autopsy information about the victim. In addition, information regarding the nature and circumstances of the fire was also obtained. RESULTS: Between 1992 and 1997, there were 674 fire-related deaths in the state of Alabama. The fire-related fatality rate was highest among older persons. The fatality rate was particularly high among older black people. The rate of fatal fires caused by heating devices was higher (15.0%) among older people compared with their young and middle-aged counterparts (6.3% and 4.5%, respectively). Fatalities among older people were least likely (26.0%) to occur if smoke detectors were present, compared with deaths among young and middle-aged persons (38.3% and 33.5%, respectively). There were fewer smoke detectors present in the fatal fires of older rural black adults and white adults (0.0% and 29.0%, respectively) compared with their urban counterparts (25.0% and 47.0%, respectively). Alcohol was not a factor in fatal fires involving older adults (29.0%) compared with those involving the young (52.0%) and middle-aged adults (73.9%). CONCLUSIONS: With the growth of the percentage of older people in the population, the problem of fire-related deaths in this age group is likely to increase. Interventions focused on this age group are necessary for the state of Alabama to meet the National Health Objectives for the year 2000.

Accidents↗