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Biomedical subjects

J V Jones

Publications and source records attributed to J V Jones.

At least 109 records · Page 6Linked to original sources
PubMed1982

Survival rates of parasite eggs in sludge during aerobic and anaerobic digestion.

The effects of mesothermic anaerobic or aerobic sludge digestion on survival of eggs from the roundworms Ascaris suum, toxocara canis, Trichuris vulpis, and Trichuris suis and from the rat tapeworm Hymenolepis diminuta were studied. Destruction of eggs throughout a 15-day treatment period, as well as their viabilities after reisolation, was analyzed. The laboratory model digesters used in this study were maintained at a 15-day retention schedule, partially simulating a continuously operating system. Ascaris eggs were destroyed in the anaerobic (23%) or aerobic (38%) digesters, and 11% Trichuris eggs were destroyed in the aerobic digesters. Trichuris eggs in anaerobic digesters and Toxocara eggs in either anaerobic or aerobic digesters were not destroyed. Destruction of eggs in digesters was correlated with the state of the eggs before subjection to the treatment processes; i.e., some Ascaris and Trichuris eggs were already embryonated in host intestinal contents or feces and hence past their most resistant stage. The viabilities of Ascaris and Toxocara eggs that survived the digestion processes were greater in anaerobically treated than in aerobically treated material. Eggs from Hymenolepis were nonviable before use in the experiments. However, they were more effectively destroyed in aerobic digesters than in anaerobic digesters.

Aerobiosis↗
PubMed1982

Neutropenia in rheumatoid arthritis: studies on possible contributing factors.

Twenty-five patients with rheumatoid arthritis (RA) and neutropenia, of whom 19 had a palpable spleen, were compared with 24 patients with uncomplicated RA, and 16 patients with RA and associated splenomegaly without neutropenia. Clinically patients with neutropenia had evidence of a more systemic disease as assessed by prevalence of rheumatoid nodules, weight loss, and recurrent infections. However, there was less evidence of active synovitis than in the other 2 groups. Marrow neutrophil reserve was studied by means of a hydrocortisone stimulation test and was found to be lower in all 3 groups than in normal persons but with most marked depletion in the neutropenic group. Removal of the spleen in some patients with neutropenia resulted in a significant increase in marrow neutrophil reserve. Circulating immune complexes as detected by anticomplementary activity and platelet aggregation tests were detected in 68% of the RA neutropenia group, 31% of the RA splenomegaly group, and 8% of the uncomplicated RA group. Our results show that, assessed both clinically and by the above tests, patients with neutropenia have a greater prevalence of abnormalities which may be directly related to their neutropenia. Patients with splenomegaly alone closely resemble patients with uncomplicated RA.

Agranulocytosis↗
PubMed1982

Pacemaker-masked hypertension in a patient with mitral stenosis.

Severe hypertension was seen in a patient with mitral stenosis when in sinus rhythm. A large fall in systolic blood pressure and in left ventricular end-diastolic pressure was caused by ventricular pacing. Contrary to the usual situation in mitral stenosis this patient paradoxically is a subject who improved haemodynamically with the loss of sinus rhythm and of atrial systole.

Aged↗
PubMed1982

Baroreflex sensitivity changes during the reversal of Goldblatt two-kidney one-clip hypertension in rats.

The time-course of changes in baroreceptor reflex sensitivity during the reversal of Goldblatt two-kidney one-clip hypertension was studied in male Wistar rats. Groups of animals were studied before and 1, 3, 7, 14 and 25 days after removal of a left renal artery clip of 0.18 mm internal diameter. Normotensive rats of comparable ages were included as controls. Baroreflex sensitivity increased from 0.299 +/- 0.072 ms/mmHg (n = 8) in 25 day hypertensive rats to 0.657 +/- 0.155 and 0.786 +/- 0.093 ms/mmHg (n = 8) in 1 day and 3 day declipped animals respectively. Baroreflex sensitivity in the 1 day declipped rats was inversely related to the level of blood pressure. Baroreflex sensitivity is restored early when renovascular hypertension is reversed. This is unlikely to be due solely to regression of structural vascular adaptation.

Animals↗
PubMed1981

Cuff and ambulatory blood pressure in subjects with essential hypertension.

Clinic cuff blood-pressure measurements, obtained on at least three occasions, were compared with mean arterial pressures in 59 patients with borderline or essential hypertension who underwent direct ambulatory monitoring of blood pressure. In 22 patients (group I) mean cuff and ambulatory pressures were similar (+/- 10 mm Hg) while in 32 subjects (group II) cuff pressures were more than 10 mm Hg higher. Groups I and II could not be distinguished on the basis of clinical examination, indices of sympathetic nerve activity, or blood-pressure variability, or by the magnitude of pressure rise during physical or mental exercise. Group II had less cardiovascular target organ damage and better baroreflex sensitivity but there was considerable overlap. There was no reliable way of telling which subjects would have lower ambulatory than cuff pressures. 20 out of 59 subjects classified as hypertensive by cuff measurements had awake ambulatory pressures or less than 140/90 mm Hg.

Adolescent↗
PubMed1981

Therapeutic plasmapheresis in systemic lupus erythematosus. Effect on immune complexes and antibodies to DNA.

The effect of plasmapheresis in 8 patients with systemic lupus erythematosus (SLE) was investigated. Drug treatment was maintained at a constant level for at least 4 weeks before plasmapheresis. Levels of immune complexes were measured by a Raji cell radioimmunoassay, and by a solid-phase C1q-binding assay. Antibodies to ds-DNA and ss-DNA were measured by the Farr assay. In all cases, immune complexes and antibodies were lowered by plasmapheresis. In 5 patients, plasmapheresis was followed by a rapid rebound of complexes and antibody to pretreatment levels. In 3 in whom plasmapheresis was followed by treatment with cyclophosphamide for 1 month, a sustained immunochemical and clinical improvement followed, lasting in 2 cases for up to 3 years.

Adolescent↗
PubMed1981

Visual loss as the initial symptom of systemic lupus erythematosus.

A 42-year-old woman had severe, bilateral visual loss and the initial symptom of systemic lupus erythematosus. Fundus photographs and fluorescein angiograms demonstrated an inflammatory process and severe ischemia. Vision in the less severely affected eye markedly improved after systemic and retrobulbar administrations of corticosteroids.

Adrenal Cortex Hormones↗
PubMed1981

Impaired immunity in patients with inflammatory bowel disease and hyposplenism: the response to intravenous phi X174.

Eight patients with inflammatory bowel disease were tested for their ability to mount a serological response to the intravenous particulate antigen phi X174. Seven patients had extensive ulcerative colitis and one patient extensive Crohn's colitis, four having severe hyposplenism and four normal splenic function. The antibody response to phi X174 was grossly impaired in those with hyposplenism.

Antibodies, Viral↗
PubMed1980

Baroreflex sensitivity changes during the development of Goldblatt two-kidney one-clip hypertension in rats.

1. The time course of changes in baroreceptor reflex sensitivity during the development of renovascular hypertension was studied in male Wistar rats in which the left renal arteries were constricted by silver wire clips of 0.18 mm internal diameter. 2. Groups of animals were studied at 3, 7, 14 and 25 days after induction of renovascular hypertension. Rats of comparable ages were included as controls. There was a significant decrease in mean baroreflex sensitivity from 0.950 +/- 0.157 ms/mmHg (n = 8) in the normal control group to 0.537 +/- 0.105 ms/mmHg (n = 8) in the 3 day hypertensive group (P < 0.05). Baroreflex sensitivity in the 3 day hypertensive rats was independent of the level of arterial pressure achieved in individual animals. 3. These changes in baroreflex sensitivity at 3 days precede the development of left ventricular hypertrophy and, as previously shown in this model, also precede structural vascular adaptation and resetting of the carotid sinus baroreceptor threshold. 4. A further loss of baroreflex sensitivity, which may be structurally based, occurred later. Baroreflex sensitivity in the 14 day hypertensive rats fell to 0.182 +/- 0.039 ms/mmHg (n = 8) compared with the 3 day hypertensive rats (P < 0.01).

Animals↗
PubMed1980

Adaptation of hypertensives to treatment with cardioselective and non-selective beta-blockers. Absence of correlation between bradycardia and blood pressure control, and reduction in slope of the QT/RR relation.

Thirty mild hypertensives were treated for more than two months with either cardioselective (atenolol or metoprolol) or non-selective (propranolol or pindolol) beta-blockers; the patients were assigned to the drugs in a double-blind manner. A procedure was designed to distinguish between the effects of the drugs themselves while treatment continued, and the development of adaptive changes which would persist when the drugs had been eliminated from the body. Though individual responses to treatment varied in both groups, the mean effect of the cardioselective and non-selective drugs in the control of hypertension was similar. There was no evidence of the development of supersensitivity or "rebound". On the contrary, an adaptive bradycardia (that is a fall of not less than 10% in heart rate persisting 52 hours after stopping treatment) was observed at rest in 17/30 patients, and peak heart rates and blood pressures during exercise were lower in both groups than before treatment. Cardioselective drugs induced a significantly greater bradycardia at rest than non-selective, but on exercise increases in heart rate were reduced more by the non-selective drugs, so that the same peak heart rates were reached on exercise in both groups. Adaptation also affected QT. The results suggest that two factors govern the shortening of QT by increases in heart rate, a "metabolic" effect, determined by sympathetic drive, and a "biophysical" effect determined by heart rate. The adrenergic effect is attenuated by acute beta-blockade, or by adaptation to prolonged blockade, leaving a shallow, rate-determined, slope to the QT/RR regression.

Adaptation, Physiological↗