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Biomedical subjects

J Butterfield

Publications and source records attributed to J Butterfield.

At least 19 recordsLinked to original sources
PubMed2006

'Idiopathic' eosinophilia with an Occult T-cell clone: prevalence and clinical course.

In a study of 99 consecutive patients with "idiopathic" eosinophilia, clonal T-cells were demonstrated in blood, bone marrow, or other tissue samples of 14 patients including 6 who had an overt T-cell malignancy. The remaining eight patients (approximately 8%) with an "Occult" T-cell clone had predominantly cutaneous disease and FIP1L1-PDGFRA was absent in all six evaluable patients. Two patients were effectively treated with low-dose oral cyclophosphamide or methotrexate whereas Gleevec treatment was ineffective in another two patients. Two patients (25%) transformed into cutaneous T-cell lymphoma after 3-8 years of eosinophilic prodrome.

Adult↗
PubMed1998

Changes in neutrophil surface phenotype during hemodialysis.

The initiation of hemodialysis using cuprophane membranes is followed by a rapid fall in the circulating neutrophil count. This neutropenia is caused by a transient sequestration of neutrophils in the lung due to homotypic aggregation, largely in response to generation of C5a by contact of plasma with the dialyzer. The transient nature of hemodialysis neutropenia is due to desensitization of neutrophils to stimulation by C5a, thus demonstrating desensitization in vivo. To examine the in vivo effects on surface phenotype of continuous exposure of neutrophils to C5a over 3 h, the surface expression of 22 antigens was examined by flow cytometry in patients undergoing dialysis. Neutropenia was prominent at 15 min and absent at 60 and 180 min of dialysis. CD10, CD11b, CD11c, CD13, CD18, CD35, CD45, CD66acde, and CD66b were upregulated at 15 min and remained upregulated at 180 min. CD61 and CD63 increased slightly at 15 min and returned to baseline by 180 min. CD16 and CD62L were down regulated at 15 min and normalized by 180 min. CD15s, CDw17, CD32, and CD44 were slightly down regulated at 15 min and then returned to baseline by 180 min. CD11a, CD15, CD24, CD31, and CDw65 did not change during dialysis. This study demonstrates the changes in surface phenotype of neutrophils during prolonged in vivo exposure to C5a over 3 h, during which time neutrophils become desensitized to subsequent stimulation by similar concentrations of C5a but maintain responsiveness to other chemotactic stimuli.

Adult↗
PubMed1993

The circulation in diabetes, from HL523 to the NO era.

In 1955, F R Barany, a Swedish research physician interested in diabetes, summarised his dissertation (Acta Med Scand 1955; suppl 1304: 127) with the words "The ultimate cause of the various abnormal vascular reactions in diabetes might be assumed to be the cause of diabetic neuropathy in which autonomic pathways are the first to be destroyed...". That diabetes might involve a microcirculatory disease affecting the autonomic nervous system may be more relevant to the following reminiscence about the agent HL523 than I realised.

Diabetes Mellitus↗
PubMed1988

Polyunsaturated fatty acids stimulate superoxide formation in tumor cells: a mechanism for specific cytotoxicity and a model for tumor necrosis factor?

Some neoplastic cell lines are readily killed when incubated in the presence of polyunsaturated fatty acids (PUFA). In an attempt to elucidate this phenomenon, we studied PUFA-driven superoxide (O2-) production by cultured NS-1 cells (murine lymphoid tumor cells). We find: (1) Even in the absence of added PUFA, NS-1 cells generate O2- (i.e., reduce nitroblue tetrazolium). (2) addition of PUFA increases O2- by greater than 50%. (3) Artificial loading of NS-1 cells with liposome encapsulated superoxide dismutase prevents the majority of spontaneous and PUFA-driven NBT reduction. We conclude that PUFA drives O2- generation by tumor cells, that this generation is largely intracellular, and that this phenomenon may help explain toxicity of PUFA for tumor cells.

Animals↗
PubMed1988

The dopaminergic D receptor: another example of reductive activation?

We have previously suggested that several intercellular messengers activate their receptors via reductive activation. Adenylate cyclase activation involves exposure of a sulfhydryl group. The dopamine D1 receptor activates this enzyme. Because sulfhydryl exposure could be secondary to reduction of a disulfide group we evaluated dopaminergic D1 agonists and antagonists as reducing agents. The agonists were found to be reducing agents and the antagonists were inactive. These results are consistent with the concept that dopaminergic D1 agonists activate adenylate cyclase via reductive activation.

Adenylyl Cyclases↗
PubMed1988

Phosphorylation of tyrosine enhances its electron transfer capability: a model of redox modulation as oncogene expression?

The influence of tyrosine and o-phosphotyrosine on the transfer of electrons to nitrobluetetrazolium (NBT) was studied. Tyrosine phosphate was found to strongly promote the transfer of electrons from ferrous iron to NBT, while tyrosine was inhibitory. The enhancement of NBT reduction by tyrosine phosphate was blocked by superoxide dismutase (SOD). The results suggest a role for phosphorylated tyrosine residues to promote intracellular redox reactions. We suggest that the role of tyrosine protein kinases in cell proliferation and transformation may be to regulate electron transport in as yet undefined cellular systems. Consistent with a unique role for phosphotyrosine, the other commonly occurring phosphoamino acids, o-phosphoserine and o-phosphothreonine were not effective electron transfer agents.

Electron Transport↗
PubMed1983

The herring gull Larus argentatus as a carrier of salmonella.

The proportion of salmonella carriers among town-nesting herring gulls increased significantly from 2.1% in 1975-6 to 8.4% in 1979. The range of serotypes carried by herring gulls was similar to that causing infection in man, and it is likely that the gulls ingest these serotypes when feeding at untreated sewage outfalls on the coast. This is supported by the proportion of salmonella carriers being higher among first-year birds (9.7%) than among older birds (2.0%), as it is known that higher proportions of immature herring gulls feed on the coast. Herring gulls carrying salmonellas appeared healthy at the time of capture and at a later date it was assumed that they were not themselves infected. However, their habit of congregating in large numbers on reservoirs and rubbish tips and also at resting sites on farmland often far from feeding and roosting areas, multiplies the pollution problem and increases the potential health hazard for both man and farm stock. Herring gulls feed at a variety of sites and fly many miles from food source to food source and from feeding areas to the roost. Thus, even within the same day, there is the possibility of the transfer of salmonellas over a much wider area than previously considered.

Animals↗
PubMed1983

The herring gull Larus argentatus as a likely transmitting agent of Salmonella montevideo to sheep and cattle.

This paper presents evidence for the involvement of herring gulls (Larus argentatus) as vectors in the recent outbreaks of Salmonella montevideo in sheep and cattle in Scotland and suggests that the transfer can take place over considerable distances. The breeding area in Scotland of herring gulls which overwinter in N.E. England is remarkably similar to the geographical distribution of the outbreaks. This pattern, together with the feeding behaviour of herring gulls on farmland, the presence of S. montevideo in herring gulls just before their departure from the wintering area and the timing of the return just before the peak of outbreaks are all circumstantial evidence implicating this gull in the outbreaks. The rapid return of these gulls to their breeding areas means that S. montevideo can be transported long distances in one day and raises the possibility that the original source of S. montevideo could have been in N.E. England rather than in Scotland.

Animals↗
PubMed1981

Surgical repair of coarctation of the aorta in infants less than six months of age: including the question of pulmonary artery banding.

High mortality rates (20% to 60%) have been reported in the repair of coarctation of the aorta in infancy. During a 4 year period, 34 infants less than 6 months of age had coarctation repair (two prior to 1976). Eleven were less than 2 weeks of age, nine were 2 weeks to 1 month, eight were 1 to 2 months, and six were 2 to 6 months. Associated lesions were patent ductus arteriosus (PDA) (82%), ventricular septal defect (VSD) (53%), and other intracardiac lesions (35%). Twenty-three patients (67%) had emergency operations; the other procedures were semielective. The indications for operation included congestive cardiac failure (91%), acidosis (32%), hypertension (29%), cardiogenic shock (26%), and cardiac arrest (18%). There was one operative death (2.9%) in a patient with severe pulmonary valve insufficiency and multiple VSDs. There was one late death a 4 months (Taussig-Bing complex). Primary repair was used in 15, patch-graft angioplasty in 19 (left subclavian artery in nine, left common carotid in one, and Dacron or pericardial patch in nine). Two (6%) required reoperation for recurrent coarctation (follow-up 3 to 36 months with a mean of 25.8). Of 15 patients with a large VSD, six had pulmonary artery banding with two deaths (one operative and one late), two had debanding plus VSD repair, and two are awaiting operation. The remaining nine patients did not have banding (no operative or late deaths), four patients required late VSD closure, two VSDs closed spontaneously, two VSDs became smaller, and one patient is awaiting VSD closure. The infrequent need for pulmonary artery banding may be partly due to "physiological banding" seen at Denver's high altitude. The VSD spontaneously closed or became smaller in 44% of nonbanded patients. The low operative mortality can be ascribed to (1) aggressive medical therapy, (2) emergency catheterization and repair, (3) avoidance of hypothermia, and (4) adequate relief of the coarctation.

Aorta↗
PubMedDate not supplied

Tail-cuff blood pressure measurement without external preheating in awake rats.

A new photoelectric sensor capable of detecting tail pulses even in unheated rats was tested for accuracy in indirect measurements of blood pressure. This sensor proved more sensitive than a Doppler ultrasonic flowmeter because it allowed detection not only of tail pulsations without preheating but also of peak oscillations usable for estimating mean arterial pressure. After blood pressures in anesthetized rats were elevated with norepinephrine or lowered with sodium nitroprusside, systolic pressures determined with the photoelectric sensor were almost identical with those recorded concurrently from femoral catheters (r = 0.939). Cuff pressure at peak oscillations in the tail correlated better with femoral mean pressure than with femoral diastolic pressure. However, similar comparisons in awake rats with chronically implanted carotid catheters showed that, although correlation between tail-cuff and carotid systolic pressures remained significant (r = 0.962), the correlation between peak tail oscillations and either mean or diastolic pressure was not. When systolic pressures were measured indirectly once a week for 7 weeks in unheated awake rats, normotensive rats could be easily distinguished from streptozotocin-diabetic and DOCA-salt hypertensive rats.

Animals↗