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Biomedical subjects

J V Jones

Publications and source records attributed to J V Jones.

At least 91 records · Page 5Linked to original sources
PubMed1987

Scleroderma and hemolytic anemia in a patient with deficiency of IgA and C4: a hitherto undescribed association.

We describe a 66-year-old women with CREST variant of scleroderma who developed autoimmune hemolytic anemia responsive to prednisone and demonstrated a deficiency of IgA and the C4 component of complement. This association of clinical, immunologic and genetic findings has not previously been reported. The literature relating to these findings is reviewed and possible mechanisms are discussed.

Aged↗
PubMed1986

Estimation of left ventricular end-diastolic pressure by pulsed Doppler ultrasound.

Left ventricular end-diastolic pressure (LVEDP) measured at cardiac catheterisation and simultaneous mitral flow patterns obtained by pulsed Doppler ultrasound scanning were assessed in twenty patients (fourteen males) with ischaemic heart disease. The ratio of passive and active components of mitral flow showed a significant linear correlation with LVEDP. Active (left atrial) mitral flow diminished as left ventricular end-diastolic pressures increased. Mitral flow ratios greater than 2 were always associated with LVEDP greater than 20 mmHg. This application of Doppler echocardiography provides a simple non-invasive method of estimating LVEDP.

Adult↗
PubMed1986

Selective medium for the isolation of Bacteroides gingivalis.

Bacteroides gingivalis has been implicated in various forms of periodontal disease and may be responsible for other diseases in humans. The role of B. gingivalis in disease has been difficult to assess, because it is inhibited by most selective media commonly used by clinical laboratories to aid in isolating gram-negative, nonsporeforming anaerobes. We have developed a new medium, Bacteroides gingivalis agar, which contains bacitracin, colistin, and nalidixic acid as selective agents. This medium allowed B. gingivalis to be isolated from oral specimens with little difficulty and also allowed B. gingivalis to be isolated from phenotypically similar Bacteroides species, such as B. asaccharolyticus and B. endodontalis, with which it can easily be confused.

Bacitracin↗
PubMed1986

Response to apheresis: problems of assessment in immune disease.

Systemic lupus erythematosus (SLE) was one of the first diseases to be treated by plasmapheresis, because of the abundance of serological disturbances, and the strong evidence that tissue damage is related to the deposition of immune complexes. Early results in small, uncontrolled studies were promising, but no large-scale controlled trials have yet been reported. The conditions for which well-controlled trials are now available are either diseases affecting a single organ-system, in which clinical abnormalities are readily measurable, such as Guillain-Barre syndrome, or conditions in which serological abnormalities correlate closely with clinical disturbances, such as myasthenia gravis. Definitive answers are also available in rheumatoid arthritis, where many years of clinical experience have led to the development of well-validated indices of clinical activity. Many studies of SLE suggest that serological abnormalities, though important, are often not quantitatively linked to the clinical manifestations of the disease. Attempts to develop indices of clinical activity for SLE are handicapped by the range of different organ systems which may be involved. Progress in the development of clinical trials of plasmapheresis in SLE is most likely to result from multicenter cooperative groups, which will have the capacity to study large enough numbers of patients for adequate stratification, and from the development and validation of indices of clinical activity, which will make possible the quantitation of clinical response, and the measurement of the rate of accumulation of permanent organ damage.

Arthritis, Rheumatoid↗
PubMed1985

Cardioselective and nonselective beta-adrenoceptor blocking drugs in hypertension: a comparison of their effect on blood pressure during mental and physical activity.

The ability of cardioselective and nonselective beta-adrenoceptor blocking drugs, with and without partial agonist activity, to control increases in blood pressure associated with mental and physical activity was compared in 35 subjects with hypertension. Direct measurements of blood pressure and radioenzymatic determinations of plasma norepinephrine were obtained before, during and after four activities, and were repeated after random allocation to treatment with atenolol, metoprolol, pindolol or propranolol. Cardioselective and nonselective drugs modestly reduced the pressor response to reaction time testing, but not to mental arithmetic or isometric exercise. The increase in systolic blood pressure during bicycling was attenuated significantly by the cardioselective drugs atenolol (by 23 mm Hg, or 38%) and metoprolol (21 mm Hg, or 41%), but not by the nonselective agents pindolol (with partial agonist activity) (13 mm Hg, or 20%) and propranolol (10 mm Hg, or 17%) (p less than 0.02 cardioselective versus nonselective; p = NS pindolol versus propranolol). Only bicycle exercise increased plasma norepinephrine concentrations (by 80%). These results suggest that beta-adrenoceptor blocking drugs will not attenuate increases in blood pressure during mental or physical activities unless intense sympathoadrenal activation also occurs. Marked elevations in circulating epinephrine, with or without norepinephrine, and peripheral beta 2-blockade appear necessary for alpha-mediated vasoconstriction to predominate and for the contrasting effects of cardioselective and nonselective drugs to be appreciated.

Adolescent↗
PubMed1984

Lithium carbonate treatment in familial cyclic neutropenia.

A patient with previously documented cyclic neutropenia was followed for 48 days on no treatment. Blood counts obtained at 3-day intervals confirmed the presence of cyclic neutropenia with virtually complete disappearance of neutrophils at the nadir of cycles with a periodicity of 21 days. Lithium carbonate treatment was begun on day 49. Serum lithium levels remained in the therapeutic range throughout the study interval of 58 days. Periodicity and depth of neutropenia were not diminished during the study period.

Adult↗
PubMed1984

Neural and humoral mechanisms involved in blood pressure variability.

In order to study blood pressure variability we have measured blood pressure, heart rate, plasma noradrenaline and adrenaline concentration and plasma renin activity during sleep and during the waking process in 20 subjects with borderline hypertension. The responses to a number of standardized tests were also measured. These were reading, mental arithmetic, change in posture, physical exercise and the response to intravenously injected phenylephrine and noradrenaline. The sensitivity of the baroreflex for heart rate control was also determined from the relationship between heart period (R-R interval) and change in systolic pressure after the injection of phenylephrine. Blood pressure was also recorded continuously for 24 hours. From the lowest levels achieved during sleep, blood pressure rose as the subjects regained consciousness but was not restored to its baseline value until mental activity was also restored by reading. Blood pressure rose further with mental arithmetic. These changes were accompanied by a greater proportional rise in plasma adrenaline than in plasma noradrenaline concentrations. Plasma renin activity changed little. The pressor responses to phenylephrine and noradrenaline were inversely related to baroreceptor sensitivity. The fall in blood pressure with sleep and the rise with mental arithmetic was also inversely related to the sensitivity of the reflex. Systolic pressure recorded throughout the day was inversely related to the R-R interval in each subject. The slope of this relationship and range of R-R interval was greatest in the subjects with the most sensitive baroreflexes.

Adolescent↗
PubMed1984

Survival of parasite eggs upon storage in sludge.

Destruction rates of parasite eggs in stored sludge were examined to help understand the fate of these agents of enteric diseases in sludge lagoons. Eggs from the roundworms, Ascaris spp., Toxocara spp., Trichuris spp., and the tapeworm, Hymenolepis spp., were treated with domestic sludges by aerobic or anaerobic processes. Sludge samples seeded with eggs were stored at 4 or 25 degrees C or in a container inserted into the ground to simulate lagoon conditions. The number of eggs recovered from the samples decreased with storage time. The viability and infectivity of eggs recovered were related to the storage temperature; i.e., the eggs stored at 4 degrees C remained viable longer than those stored at 25 degrees C. After 25 months at 4 degrees C, the Toxocara eggs and some Ascaris eggs remained both viable and infective, whereas most of these eggs stored at 25 degrees C were rendered nonviable after 10 to 16 months of storage in sludge. Although storage temperature was found to be the most important factor affecting the destruction and viability of these eggs, other factors, such as the type of sludge digestion, whether or not the eggs were digested along with the sludge or added later, storage in the soil versus sludge, pH, and egg species also exhibited some minor effects. These controlled laboratory studies suggest that lagooning of sludge can be an effective method for the elimination of parasite eggs, particularly in warmer geographical locations.

Animals↗
PubMed1984

Assay, purification and further characterization of 7S C1q-precipitins (C1q-p) in hypocomplementemic vasculitis urticaria syndrome and systemic lupus erythematosus.

C1q-precipitins (C1q-p) are comprised of 7S IgG with C1q-binding activity found in sera of patients with hypocomplementemic vasculitis urticaria syndrome ( HVUS ) and systemic lupus erythematosis (SLE). We have utilized C1q-coated polystyrene beads to selectively isolate C1q-p and to establish a sensitive and quantitative assay of C1q-p and immune complex activity. Purified C1q-p was comprised of polyclonal IgG which retained 7S sedimentation and solid phase C1q-binding activity at physiological ionic strength both in the presence and absence of normal human sera. No precipitation interaction was observed between C1q-p and fluid-phase C1q or C1 under the conditions tested. Purified C1q-p had no activity in the Raji cell immune complex activity. C1q-p activity also was observed in and purified from SLE serum; this activity was distinguishable from 7S immune complex activity detected by Raji cells which was also present in SLE serum. These studies indicate that C1q-p is a 7S IgG molecule found in HVUS as well as some SLE sera and has activity in C1q-binding but not in Raji cell-binding immune complex assays. These data also suggest that C1q-p is a monomeric, polyclonal IgG with preferential affinity for bound C1q. In addition to its potential role in immune complex disease, C1q-p may also provide an important tool for studying the interaction of immunoglobulin and C1q, and should contribute important information to understanding the pathobiology of immune complex disease.

Antigen-Antibody Complex↗
PubMed1984

Ischaemic brain damage induced by rapid lowering of arterial pressure in hypertension.

Mean arterial pressure (MAP) and cerebral blood flow were monitored in six normotensive [MAP = 99 +/- 3 mmHg (s.e.m.)] and seven baboons with renovascular hypertension (MAP = 140 +/- 5 mmHg). Arterial pressure was decreased sufficiently rapidly and for a sufficient time, as determined by the electroencephalogram (EEG), to result in ischaemic brain damage. Using a combination of a bolus injection of trimetaphan, head-up tilt and acute withdrawal of blood, an isoelectric EEG was achieved at a higher MAP in the hypertensive (32 +/- 2 mmHg) than in the normotensive (19 +/- 1 mmHg: P less than 0.001) animals. Cerebral blood flow decreased to an equivalent degree in both groups. Ischaemic brain damage accentuated in the arterial boundary zones was seen in five normotensive and six hypertensive animals. This is further evidence that the resistance vessels in chronic hypertension may limit the degree of hypotension (therapeutic or accidental) that can be tolerated by the hypertensive patient.

Animals↗
PubMed1983

Relationship of clinical findings in systemic lupus erythematosus to seroreactivity.

We have characterized 52 consecutive patients fulfilling 4 or more of the American Rheumatism Association criteria for systemic lupus erythematosus in order to provide, for the first time, a homogeneous sample for statistical comparison of antinuclear antibody (ANA)-positive and ANA-negative groups. Ten patients (19%) were seronegative. There was no significant difference in age, disease activity, organ system involvement, erythrocyte sedimentation rate, immune complex levels, or C3 levels. The ANA-negative group showed a higher incidence of involvement for whites and men. Leukopenia, lower levels of antibody to DNA, and higher C4 levels were also characteristic of the ANA-negative group.

Adult↗
PubMed1983

Therapeutic trial of cryofiltration in patients with rheumatoid arthritis.

Cryofiltration, a new technique for on-line plasma separation and its treatment by cold filtration, enables the selective removal of immune complexes and eliminates the need for replacement proteins. Fifteen patients with rheumatoid arthritis were treated for nine to 10 consecutive sessions over a three- to five-week period. Circulating immune complexes decreased by an average of 78 percent and rheumatoid factor by 32 percent. This was accompanied by significant clinical improvement in morning stiffness, articular index, 50-foot walking time, grip strength, and target joint circumference. Cryofiltration might thus be beneficial for a subgroup of rheumatoid arthritis patients in whom conventional therapy has failed.

Arthritis, Rheumatoid↗
PubMed1983

Effect of chronic alcohol ingestion on the heart and blood pressure of spontaneously hypertensive rats.

The effect on the heart of a combination of high blood pressure and chronic alcohol ingestion was studied in spontaneously hypertensive rats (SHR) fed ethanol in their drinking water in concentrations of 0%, 5% and 20% for sixteen weeks. Normotensive Wistar rats were used as controls (NCR). In addition some SHR were given alcohol for a shorter period of eight weeks at the end of which time there were no significant differences in mean arterial blood pressure between the groups. After sixteen weeks of ethanol the mean arterial pressure had fallen in those SHR receiving 20% ethanol to 136 +/- 24 mmHg compared to control (180 +/- 27 mmHg; P less than 0.001). This was associated with a lower left ventricular (LV)dp/dt (control 4800 +/- 872 mmHg sec-1; 20% ethanol group = 3450 +/- 1588 mmHg sec-1; P less than 0.025) and a reduced LV weight (corrected for body weight) due to an apparent lack of development of LV hypertrophy between eight and sixteen weeks. Similarly LV volume (corrected for LV weight), did not change from eight weeks to sixteen weeks in those SHR receiving 20% ethanol in contrast to the 0% ethanol SHR group in whom LV volume fell as LV hypertrophy developed. 5% Ethanol had no significant effect on mean arterial pressure, LV peak dp/dt, LV weight or LV volume. In the NCR ethanol had little effect on mean arterial pressure but those receiving 20% ethanol had significantly smaller LV volumes without any increase in LV weight probably reflecting blood volume depletion. Ethanol did not produce any blood pressure elevation in the NCR. No rats (SHR or NCR) developed overt heart failure or a typical cardiomyopathy. However, this study has shown that a high intake of ethanol reduces the blood pressure of a hypertensive rat most likely by its direct toxic action on the myocardium. Thus with chronic alcohol ingestion hypertension can be masked but may still contribute significantly to the development of myocardial disease.

Alcoholism↗
PubMed1983

Calcium sensitivity and cardiac performance in genetic and renal models of hypertension.

We have compared cardiac performance, hypertrophy and sensitivity to calcium and verapamil of hearts of six to nine-month-old spontaneously hypertensive rats (SHR), two-kidney, one clip renal hypertensive rats (RHR) and age-matched controls. Cardiac output and heart rate were measured using an isolated perfused heart preparation. Mean blood pressure (BP) and heart weight were equally increased in SHR and RHR as was optimal left atrial filling pressure. Cardiac output was increased in both SHR and RHR at any given work load; this improvement was seen especially in SHR and at high aortic pressure (160 cm H2O) was significant in SHR but not RHR. In low [Ca2+], 0.6 mM, cardiac output of RHR and controls fell markedly, but changed little in SHR, whereas in high [Ca2+], 5.1 mM, cardiac performance deteriorated in SHR but was improved in RHR and controls. Verapamil 2 X 10(-7) M reduced Ca2+ responsiveness of RHR and controls threefold but had no effect in SHR. The results suggest there may be an abnormality of cardiac calcium utilization in inherited but not in acquired hypertension.

Animals↗
PubMed1983

Antibody to Ro in a population of patients with systemic lupus erythematosus: distribution, clinical and serological associations.

Anti-Ro occurs in 1/3 of systemic lupus erythematosus (SLE) patients with equal prevalence at all ages, ages at onset of SLE, and disease durations. In SLE anti-Ro is associated with xerophthalmia but not rheumatoid factor (RF). Anti ds-DNA rather than anti-Ro or RF is associated with SLE arthritis. We found a positive correlation between increased anti ds-DNA levels and the prevalence of anti-Ro in SLE patients' sera. This reinforces the thesis that anti-Ro may have considerable value as a diagnostic marker for SLE.

Adult↗
PubMed1982

Ambulatory blood pressure during once-daily randomised double-blind administration of atenolol, metoprolol, pindolol, and slow-release propranolol.

Intra-arterial ambulatory blood pressure was measured over 24 hours, in 34 patients with newly diagnosed hypertension, both before and after double-blind randomisation to treatment with atenolol (n=9), metoprolol (n=9), pindolol (n=9), or propranolol in its slow-release form (n=7). The dosage of each drug was adjusted at monthly clinic visits until satisfactory control of blood pressure was achieved (140/90 mm Hg or less by cuff) or the maximum dose in the study protocol was reached. A second intra-arterial recording was made after these drugs had been taken once daily at 0800 for three to eight months (mean 5.0+/-SD 1.4) and was started four hours after the last dose.At the end of the 24-hour recordings blood pressure was significantly lower with all four drugs. The extent to which the drugs reduced blood pressure, however, differed over the 24 hours. Atenolol lowered mean arterial pressure significantly throughout all 24 recorded hours, metoprolol for 12 hours, pindolol for 15 hours, and slow-release propranolol for 22 hours. Neither metoprolol nor pindolol lowered blood pressure during sleep. A significant reduction in heart rate was observed over 20 hours with atenolol, 20 hours with metoprolol, 10 hours with pindolol, and 24 hours with slow-release propranolol. Atenolol, metoprolol, and slow-release propranolol continued to slow the heart rate 24 hours after the last tablet was taken; this effect on heart rate, however, was not sustained throughout the second morning in those patients taking atenolol. Pindolol, the only drug studied that has intrinsic sympathomimetic activity, increased heart rate and did not lower blood pressure during sleep.Atenolol and slow-release propranolol are effective as antihypertensive agents over 24 hours when taken once daily, whereas metoprolol and pindolol may need to be taken more frequently. At times of low sympathetic tone, however, such as during sleep, beta-blockers with intrinsic sympathomimetic activity may raise heart rate and attenuate the fall in blood pressure with treatment.

Adolescent↗