Observations on the biology and control of the chewing louse (Bovicola limbata) of Angora goats in Great Britain.
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Biomedical subjects
Publications and source records attributed to B Groves.
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Lesional area was estimated and lesional mast cells and eosinophils were counted during primary and challenge infestations of sheep with Psoroptes ovis. In addition, circulating basophils and eosinophils and serum P. ovis-specific immunoglobulin IgE antibody were quantified. Expansion of lesional area was significantly less and serum IgE titres significantly greater in challenge than primary infestations. Lesional mast cell hyperplasia and massive eosinophil infiltration accompanied by raised titres of P. ovis antigen-specific IgE antibody were compatible with an IgE-mediated Type-1 allergic reaction, while detection of lesional basophils was suggestive of cutaneous basophil hypersensitivity. The temporal pattern of lesional mastocytosis and eosinophil infiltration and the role of these cells and serum IgE in the immune response is discussed.
The plexiform lesion in primary pulmonary hypertension is a glomeruloid structure forming channels in branches of the pulmonary artery. These lesions have been considered an abnormal growth of modified smooth muscle cells. We present immunohistochemical evidence in 10 cases of plexogenic pulmonary hypertension that the plexiform channels and the concentric obliterative arteriopathy associated with these channels represent abnormal growth of factor VIII-related antigen-positive endothelial cells. In addition, these cells strongly expressed vimentin, a growth- and differentiation-related intermediate filament. Morphologically and immunohistochemically, the lesions resembled the neovascularization associated with the brain tumor glioblastoma multiform. Furthermore, we noted an exclusively perivascular inflammatory cell infiltrate (but no vasculitis) in seven of the 10 cases with plexogenic arteriopathy composed of T cells, B cells, and macrophages. Our findings indicate that the plexiform lesion may result from a deregulated growth of endothelial cells. The presence of perivascular inflammatory cells suggested that cytokines and growth factors may further influence the development of the plexiform lesion.
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To evaluate the effect of extreme altitude on cardiac function in normal young men, electrocardiograms were recorded at rest and during maximal exercise at several simulated altitudes up to the equivalent of the summit of Mt. Everest (240 torr or 8,848 m). The subjects spent 40 days in a hypobaric chamber as the pressure was gradually reduced to simulate an ascent. Changes in the resting electrocardiogram were evident at 483 torr (3,660 m) and were more marked at 282 torr (7,620 m) and 240 torr (8,848 m). They consisted of an increase in resting heart rate from 63 +/- 5 to a maximum of 89 +/- 8 beats/min; increase in P-wave amplitude in inferior leads; right-axis shift in the frontal plane; increased S/R ratio in the left precordial leads; and increased T negativity in V1 and V2. No significant arrhythmias or conduction defects were observed. Most changes reverted to normal within 12 hours of return to sea level, with the exception of the frontal-plane axis and T-wave alterations. Maximal cycle ergometer exercise at 282 torr (7,620 m) and 240 torr (8,848 m) resulted in a heart rate of 138 +/- 7 and 119 +/- 6 beats/min at the 2 altitudes, respectively. No ST depression or T-wave changes suggestive of ischemia occurred despite a mean arterial oxygen saturation of 49% and a mean pH of 8 during peak exercise. Occasional ventricular premature beats were observed during exercise in 2 subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Mucocutaneous lymph node syndrome (MLNS), or Kawasaki's disease, affects thousands of infants and children each year and is associated with a high incidence of coronary artery aneurysm, which may lead to subsequent myocardial infarction. Successful use of the right subclavian-axillary artery to bypass a thrombosed aneurysm of the left anterior descending coronary artery is documented angiographically and forms the basis of this report. A management plan for MLNS patients is proposed.
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