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Biomedical subjects

S Jones

Publications and source records attributed to S Jones.

At least 469 records · Page 26Linked to original sources
PubMed1991

Self-poisoning patients discharged from accident and emergency: risk factors and outcome.

In a prospective audit of 1,096 consecutive attendances by deliberate self-poisoning patients at an accident and emergency department (A&E), such patients were discharged directly from A&E on 31% of occasions. Outcome and risk were compared for patients admitted to hospital and discharged directly from A&E. In the following year repetition of self-poisoning occurred in the same proportions of patients admitted to hospital and discharged from A&E (12%, relative risk 1.02). Suicide during the following three years occurred in 1.3% of patients admitted and 1.1% of those discharged (relative risk 1.2). Patients admitted to hospital from A&E were those likely to be at greater risk: they were older, reported more physical ill-health, expressed a threat or left a note more often, and had more frequently experienced psychiatric inpatient care. Thus, nearly one-third of deliberate self-poisoning attenders were discharged from A&E; outcomes were similar despite higher risk among admitted patients, suggesting that brief admission has some benefit.

Adolescent↗
PubMed1990

Comparison of lymphangiography and computed tomography scanning in evaluating abdominal disease in stages III and IV Hodgkin's disease. A Southwest Oncology Group study.

The authors reviewed the records of 139 patients who had laparotomy plus computed tomography (CT) and/or lymphangiograms (LAG) as part of a their staging workup for Hodgkin's disease, in accordance with Southwest Oncology Group (SWOG) protocol 7808. They evaluated the relative ability of CT and LAG to detect disease in the abdomen. Two regions of the abdomen were designated, the upper and the lower, to further examine the capabilities of CT and LAG in the lower abdomen and CT in the upper abdomen. A LAG was more sensitive (P less than 0.05) than CT in detecting positive lower abdominal nodes. In the upper abdomen, CT scan had low sensitivity for detecting positive nodes, liver, or spleen. This study suggests that LAG of the lower abdomen provided more information than CT, and therefore should not be abandoned as a valid method for detecting nodal disease.

Abdomen↗
PubMed1990

Adrenaline and nocturnal asthma.

OBJECTIVE: To determine whether the nocturnal fall in plasma adrenaline is a cause of nocturnal asthma. DESIGN: Double blind placebo controlled cross-over study. In the first experiment the nocturnal fall in plasma adrenaline at 4 am was corrected in 10 asthmatic subjects with an infusion of adrenaline after parasympathetic blockade with 30 micrograms/kg intravenous atropine. In the second experiment 11 asthmatic subjects showing similar variations in peak expiratory flow rate had the nocturnal fall in plasma adrenaline corrected by infusion before atropine was given. PATIENTS: Asthmatic subjects with a diurnal variation in home peak expiratory flow rate of greater than 20% for at least 75% of the time in the two weeks before the study. MAIN OUTCOME MEASURES: Peak expiratory flow rate and plasma adrenaline. RESULTS: Correction of the nocturnal fall in plasma adrenaline at 4 am to resting 4 pm levels did not alter peak expiratory flow rate either before or after parasympathetic blockade with atropine. CONCLUSION: A nighttime fall in plasma adrenaline is not a cause of nocturnal asthma.

Adult↗
PubMed1990

Oral contraceptive use, human papillomavirus infection, and risk of early cytological abnormalities of the cervix.

Oral contraceptive (OC) use was examined as a risk factor for cytological abnormalities of the cervix among 1964 women receiving Papanicolaou smears at three hospitals in the Washington, D.C., area. A single pathologist classified cytological results from all women as normal (n = 1423), atypia (n = 314), low grade squamous intraepithelial lesion (SIL; n = 208), or high grade SIL (n = 19). Women in each of the three abnormal groups were compared to women with normal cytological diagnoses. A subset of 579 patients, including most of the women with low or high grade SIL and a matched group of controls, was tested for human papillomavirus (HPV) by type-specific Southern blot hybridization to examine the effects of OC use while taking into account the effects of HPV infection. OC use was found to be unrelated to risk of atypia or low grade SIL but was associated with an elevated risk of high grade SIL that increased with longer duration of use (relative risk = 4.6, 95% confidence interval = 1.1-18.1 for greater than or equal to 5 years of use). HPV infection was associated, as expected, with risk of low and high grade SIL but not with atypia. Taking the HPV results into consideration did not alter the OC findings. There was no evidence that OC use synergistically increased the risk of cervical neoplasia among HPV-infected women, although small numbers prevented a reliable evaluation for high grade SIL. OC use did appear to increase the detection of HPV types 16/18, but the etiological importance of this finding is unclear.

Adult↗
PubMed1990

Bladder surface glycosaminoglycans: an epithelial permeability barrier.

Sulfated polysaccharide's ability to modulate the movement of small molecules was examined both in vivo and in vitro. For the in vivo test, the rabbit bladder was utilized and C-14 labeled urea 45-Ca, or 3H2O was placed into the lumen of control bladders, bladders pretreated with protamine sulfate (20 mg./cc) and bladders pretreated with protamine sulfate (20 mg./cc) plus pentosanpoly-sulfate (PPS), 10 mg./cc. After 45 minutes, the controls absorbed 21% of the urea, 16% of the calcium, and 38% of the 3H2O; the protamine treated group 40% urea, 23% calcium, and 51% H2O; the PPS only group 22% urea and the protamine plus PPS group absorbed 24% of urea, 18% calcium, and 44% water. Differences between the control and protamine groups were statistically significant, p less than 0.01 for urea 45-Ca and 3H2O. The bladder mucosa contained a significantly higher concentration of urea and calcium after protamine treatment which were both reversed by PPS (p less than 0.01) while 3H2O content went down significantly (p = 0.03), reflecting a loss of the hydrophilic effect of bladder GAG. The control mucosas had 250 cpm/mg. tissue urea for Ca 64 cpm/mg. and water 262 cpm/mg., the protamine group urea 498 cpm/mg., Ca 190 cpm/mg., and H2O 139 cpm/mg.; the protamine plus PPS group urea 344 cpm/mg., Ca 129 cpm/mg., and water 168 cpm/mg. For the in vitro studies, an Ussing chamber was employed. Normal rabbit bladder membranes were placed in the chambers and the potential difference was zeroed across the membrane. There were three groups, membranes that were treated only with the irrigating solution, membranes pretreated with protamine, and membranes pretreated with protamine plus PPS. At the end of 40 minutes, there was an approximately 1.2% movement of urea across the control membrane, a 3.5% movement across the protamine treated membrane (a significant increase p less than 0.001) and a 1.1% movement across the protamine plus PPS treated membrane. It would appear that the surface polysaccharide may play an important role as a bladder permeability barrier in modulating both charged and uncharged small molecule movement in that its ability to impair such movement can be inhibited by protamine and this protamine effect can be reversed by a treatment with an exogenous sulfated polysaccharide.

Animals↗
PubMed1990

Response of monkeys to vaccination with recombinant vaccinia virus which coexpress HIV gp160 and human interleukin-2.

Immunization of two macaque monkeys with recombinant vaccinia viruses encoding the env gene of HIV-1 (VV-gp160) resulted in demonstrable levels of gp160, gp120 and gp41-specific immunoglobulins in both animals. The virus used to immunize one of the monkeys additionally expressed the human IL-2 gene, which encoded human IL-2 (VV-gp160-IL-2). No toxic side-effects of vaccine-delivered IL-2 were observed. Despite marked attenuation of virulence by the coexpressed lymphokine, the levels of vector-specific antibodies in both animals were similar. Some differences in the HIV-specific reactivity patterns were detected. Serum reactivity of monkey #A56 (VV-gp160) was directed against gp41, whereas monkey #B58 (VV-gp160-IL-2) showed a wider range of recognition, with higher antibody titres against the HIV lysate preparation. Furthermore, this study demonstrates the capacity to boost antibody responses to the vector and coexpressed HIV antigens in primates which are already immune.

Animals↗
PubMed1990

Renal, metabolic and hormonal responses to ingestion of animal and vegetable proteins.

Renal and hormonal responses were studied in a group of healthy individuals fed, in random order, for three weeks, a vegetable protein diet (N = 10), an animal protein diet (N = 10), or an animal protein diet supplemented with fiber (N = 7), all containing the same amount of total protein (chronic study). In seven additional subjects the acute renal, metabolic and hormonal response to ingestion of a meat or soya load of equivalent total protein content was investigated (acute study). In the chronic study GRF, RPF and fractional clearance of albumin and IgG were significantly higher on the animal than the vegetable protein diets (GFR: 121 +/- 4 vs. 111 +/- 4 ml/min/1.73 m2, P less than 0.001; RPF: 634 +/- 29 vs. 559 +/- 26 ml/min/1.73 m2, P less than 0.001; theta alb: 19.5 +/- 3.1 vs. 10.2 +/- 1.6 x 10(-7), P less than 0.01; theta IgG: 11.6 +/- 3.1 vs. 7.5 +/- 1.7 x 10(-7), P less than 0.05). Renal vascular resistance was lower on the animal than vegetable protein diet (82 +/- 5 vs. 97 +/- 5 mmHg/min/liter; P less than 0.001). Fiber supplementation to APD did not have any effect on the renal variables measured which were indistinguishable from APD. In the acute study, GFR and RPF both rose significantly by approximately 16% (P less than 0.005) and approximately 14% (P less than 0.05), respectively, after the meat load, while RVR fell by approximately 12% (P less than 0.05). There were no significant changes in these parameters following the soya load.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Effect of activation sequence on ventricular refractoriness as determined by extrastimuli.

STUDY OBJECTIVE: The aim was to determine by the extrastimulus method the effect on the right and left ventricular effective refractory periods of moving the site of the pacing train away from the site of the extrastimulus. DESIGN: The ventricular effective refractory period was measured at the right and left ventricular apices using pacing trains at two heart rates, delivered to the ipsilateral ventricle, the contralateral ventricle, and the right atrium. SUBJECTS: Seven patients (six male), mean age 52 years (range 26-75 years), with either documented (six) or suspected (one) ventricular tachycardia were studied. Four had ischaemic heart disease and the remaining three had morphologically normal hearts. MEASUREMENTS AND MAIN RESULTS: The pacing train and extrastimulus delivered in the right ventricle produced the shortest effective refractory period at both heart rates: 220.8(SD 19) ms and 207.9(16) ms respectively. As the pacing train was moved to the right atrium, the effective refractory period lengthened to 246.4(22) ms and 219.3(20) ms at the two heart rates. There was further lengthening as the site of the pacing train was moved to the left ventricle, to 269.2(20) ms and 240.7(35) ms respectively. The same pattern was observed in the left ventricular effective refractory periods as the pacing train was moved from left ventricle to right ventricle and to right atrium. CONCLUSIONS: The ventricular effective refractory period lengthens as the site of the pacing train is moved away from the site of the extrastimulus. This may be explained by the effects of the distribution of the pacing energy within the myocardium and by intercellular electrotonic interactions. This has important clinical implications for the arrhythmogenic mechanisms of ventricular tachyarrhythmias.

Adult↗
PubMed1990

Adrenal cortical adenoma in the spinal canal of an 8-year-old girl.

An ectopic adrenal cortical adenoma containing high levels of androstenedione but without clinically detectable virilizing effects was found in the spinal intradural space of an 8-year-old girl. The tumor, which was located at the L2 level, manifested itself clinically by a short history of bilateral leg pain. It was well encapsulated; therefore, total surgical removal was accomplished. The light microscopic appearance of the tumor was typical of adenomatous adrenal cortical tissue. Ultrastructurally, it also showed characteristic features of steroid-producing tumors, including very abundant smooth endoplasmic reticulum and giant mitochondria with tubulovesicular and circular cristae. Frozen tissue analyzed by radioimmunoassay was found to contain almost 20 times the normal tissue level of androstenedione. There was no elevation of cortisol or aldosterone levels in the tumor. Postoperative magnetic resonance imaging (MRI) scan of the retroperitoneum showed no abnormalities in the patient's adrenal glands. Serum androstenedione levels were normal. We postulate that the adenoma developed from congenital ectopic rests of intraspinal adrenal tissue. Although ectopic occurrence of adrenal cortical tissue has been recorded in other areas, neither such rests nor tumors developing from them have been previously reported within the spinal canal.

Adenoma↗
PubMed1990

The quality of self-monitoring of blood glucose.

The accuracy of self-monitoring of blood glucose (SBGM) was assessed by a quality control programme. Ninety diabetic patients who were routinely performing SBGM were supplied with a series of quality control solutions which they tested with their usual meter and reagent strip. The overall error rate (a result outside the range of the mean +/- 3SD for each quality control solution) was 39% for users of the Ames system and 33% in Boehringer Mannheim system users. The clinical relevance of these errors was determined by examining the effect on the clinical decision which would have been based on the erroneous result, either in taking inappropriate action or in failing to take appropriate action. In 30% of all patients, 25% or more of the errors were of such a degree as to be clinically misleading. The most common error was an underestimation of the result, which gave the impression of better than actual blood glucose control. The main reason for these errors was the failure of patients to take sufficient care in following the manufacturers' instructions when performing the test. Clinically relevant erroneous results are common among patients performing SBGM.

Blood Glucose↗
PubMed1990

Cloning and expression of alpha-amylase from Bacillus amyloliquefaciens in a stable plasmid vector in Lactobacillus plantarum.

Lactobacillus plantarum is used in a wide range of agricultural and food fermentations. In this paper we report the introduction of alpha-amylase into the organism from Bacillus amyloliquefaciens on a stable recombinant plasmid. The genetically manipulated organism grew on MRSB medium supplemented with starch and it may be a prototype for the development of lactobacilli able to use an increased range of substrates in commercial fermentations.

Bacillus↗
PubMed1990

Endocardial pacing in infants and children 15 kg or less in weight: medium-term follow-up.

Twenty-four children 15 kg or less in weight (range 2.8-15 kg) underwent implantation of a permanent pacemaker using the transvenous technique of lead placement. During a follow-up period of 2 months to 6 years 1 month (median 3 years 6 months) eight children suffered complications, six of which necessitated reoperation. These included: lead fracture in two, infection in two, transient myocardial dysfunction in one, generator migration in one, premature battery depletion in one, and threshold rise in one. A loop of redundant ventricular lead positioned in the atrium at the time of implant is successfully unravelling in all children. One child died during the follow-up period of a pneumonia unrelated to her pacemaker. The other children are growing and developing normally and the cosmetic appearance has proved acceptable in all cases.

Body Weight↗
PubMed1990

Impaired renal response to a meat meal in insulin-dependent diabetes: role of glucagon and prostaglandins.

The renal response to 100 g/1.73 m2 protein load in the form of a meat meal was studied in 19 normal subjects and 35 normoalbuminuric insulin-dependent diabetic patients (IDDs) under conditions of sustained euglycemia. The area under the glomerular filtration rate (GFR) curve rose above base line by 1,904 +/- 292 in normals and 502 +/- 237 ml/1.73 m2 in IDDs (P less than 0.01). The meat meal induced a greater increment in the area under the glucagon curve in normals (14,930 +/- 186 pg.ml-1.min-1) than in IDDs (7,227 +/- 67, P less than 0.01); similarly urinary excretion of prostaglandin E2 and 6-ketoprostaglandin F1 alpha rose by 119 and 98%, respectively, in normals but only by 2% (P less than 0.01 vs. normals) and 10% (P less than 0.01 vs. normals) in IDDs. The fractional albumin clearance rose by 102 and 251% in normals and IDDs, respectively. In five normal subjects indomethacin administration abolished the GFR, glucagon, prostaglandin, and albuminuric response to meat ingestion. Glucagon replacement under indomethacin treatment failed to restore these responses. In five diabetic patients, selected for having a flat glucagon and GFR response to a meat meal, replacement of glucagon to postprandial levels increased urinary vasodilatory prostaglandins and restored a normal GFR response. Thus in normal subjects renal vasodilatory prostaglandins appear to be the final effector of the renal hemodynamic and albuminuric response to a meat meal. The prostaglandin increase is likely to be mediated under physiological conditions by a glucagon rise, which, however, has no effect per se on renal hemodynamics.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗