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Biomedical subjects

N Taub

Publications and source records attributed to N Taub.

At least 19 recordsLinked to original sources

Clinical and lesion morphologic determinants of coronary angioplasty success and complications: current experience.

OBJECTIVES: This study evaluated the validity of the American College of Cardiology/American Heart Association ABC lesion classification scheme and its modifications. BACKGROUND: With the continued refinement in angioplasty technique and equipment evolution, the lesion morphologic determinants of immediate angioplasty outcome have changed significantly. Hence, the validity of the classification scheme has been questioned. METHODS: We assessed the lesion morphologic determinants of immediate angioplasty outcome in 729 consecutive patients who underwent coronary angioplasty of 994 vessels and 1,248 lesions. RESULTS: Angioplasty success was achieved in 91% of lesions, and abrupt closure occurred in 3%. Success was achieved in 96%, 93% and 80% of type A, B and C lesions, respectively (A vs. B, p = NS; B vs. C, p < 0.001; A vs. C, p < 0.001; A vs. B1, p = NS; A vs. B2, p = 0.03; B1 vs. B2, p = 0.02; B2 vs. C, p < 0.001; C1 vs. C2, p = NS). Abrupt closure occurred in 2.1%, 2.6% and 5% of type A, B and C lesions, respectively (A vs. B, B vs. C, A vs. C and A vs. B1, all p = NS; B1 vs. B2, p = 0.01; B2 vs. C1, p = NS; C1 vs. C2, p = 0.04). Type B characteristics had a success rate ranging from 74% to 95% and an abrupt closure rate ranging from 2.2% to 14%. Type C characteristics had a success rate ranging from 57% to 88% and an abrupt closure rate ranging from 0% to 16%. Longer lesions, calcified lesions, diameter stenosis of 80% to 99% and presence of thrombus were predictive of a lower success rate. Longer lesions, angulated lesions, diameter stenosis of 80% to 99% and calcified lesions were predictive of an abrupt closure. CONCLUSIONS: The previously proposed classification schemes are outdated and need to be changed for application in current angioplasty practice. Analyzing specific lesion morphologic characteristics rather than applying a simple lesion classification score when evaluating angioplasty outcome may be more useful because it provides a more precise profile of the lesion and allows better patient stratification and selection.

Adult

Oxidisability of low density lipoproteins in patients with carotid or femoral artery atherosclerosis.

Oxidation of low density lipoprotein (LDL) is implicated in the pathogenesis of atherosclerosis. In this study the susceptibility to oxidation of LDL (from patients with atherosclerosis) is related to the progression of the disease. LDL were isolated from 37 patients with demonstrable atherosclerotic plaques. The susceptibility of LDL to oxidation (induced by an exogenous oxidative stress) was assessed by measuring the breakdown products of lipid peroxidation, the increased formation of conjugated dienes, and changes in surface charge of the apolipoprotein B (apo B). Progression of the atherosclerotic plaque was assessed by measuring the maximum velocity of blood through the narrowest portion of the vessel at inclusion and after one year. Twenty-nine of the 37 samples taken were found to have LDL that were partially oxidised, whereas 8 samples showed LDL whose state of oxidation was within the normal range. Progression of the atherosclerotic plaque occurred in 19 (66%) of the 29 patients whose lipoproteins were partially oxidised compared with only 2 (25%) of the 8 patients with normal lipoproteins (P = 0.055, Fisher's exact test). These data support an association between the progression of atherosclerotic plaques in carotid and femoral vessels and the susceptibility to oxidation of LDL.

Aged

Difference in prevalence of gestational diabetes and perinatal outcome in an innercity multiethnic London population.

In order to establish the prevalence of gestational diabetes mellitus (GDM) among ethnic groups residing in the catchment area of one hospital in central London and to assess both the mode of delivery and the baby outcome, we studied retrospectively 703 women selected for screening for GDM during the years 1991 and 1992. While the prevalence of GDM was approximately 2% overall, within the ethnic groups a significant difference was found with Asians and Africans/Afrocaribbeans being four and two times more likely to have GDM, respectively, than Caucasians (P < 0.001). Both maternal obesity and the diagnosis of GDM influenced the time and the mode of delivery, but perinatal mortality and morbidity did not differ significantly between women with GDM and women with normal glucose tolerance. An association between the GTT glucose area and the gestational age and ethnicity adjusted birth weight was observed in women with normal glucose tolerance test, but was absent in the GDM pregnancies, providing indirect evidence that dietary treatment, with or without insulin treatment, altered the maternal milieu in the latter sufficiently to modify fetal growth.

Adult

Percutaneous transluminal coronary angioplasty of aorta ostial, non-aorta ostial, and branch ostial stenoses: acute and long-term outcome.

The acute and long-term outcome of 198 patients who underwent coronary angioplasty of ostial stenoses was evaluated. Procedural success was achieved in 85% of aorta ostial stenoses, 90% of non-aorta ostial stenoses, and 87% of branch ostial stenoses (P = 0.84). A major complication occurred in 5.9%, 6.3%, and 6.9% of patients who underwent aorta ostial, non-aorta ostial, and branch ostial stenosis angioplasty, respectively (P = 0.97). A greater residual stenosis (P = 0.005) resulted from angioplasty of aorta ostial lesions despite a greater inflation frequency (P < 0.001), inflation pressure (P < 0.001), and total inflation duration (P < 0.001). The restenosis rate was higher for aorta ostial lesions (71%) when compared to non-aorta ostial (60%) and branch ostial lesions (32%) (P = 0.01). However, since the denominator included only the 49% who returned for repeat coronary angiography, the exact angiographic restenosis rate cannot be determined. The cumulative probability of survival was 99% at 1 year and 93% at 3 years. The 1 and 3 year freedom from death, myocardial infarction, bypass surgery, and repeat angioplasty was 70% and 57%, respectively. At census, 57% were asymptomatic, and only 9% suffered severe angina. Coronary angioplasty of ostial stenoses can be carried out with an acceptable success and complication rate, and provides good symptomatic relief and favourable long-term outcome. Randomized trials to compare new angioplasty technology with balloon angioplasty will be necessary to select the best device therapy for ostial lesions.

Adult

The distribution and abnormal morphology of plasma cells in rheumatoid synovium.

This study assessed the distribution and structural features of plasma cells in rheumatoid synovial tissue. Plasma cells were found to be the predominant infiltrating mononuclear cells (mean 40%) in relation to lymphocytes and monocytes, and there was a direct relationship between their number in the infiltrates and the total number of mononuclear leucocytes (P = 0.007). Plasma cells were also seen in intimate contact with macrophages intermixed with synovial lining cells, and closely associated with small blood vessels. They often surrounded these blood vessels and sometimes were seen lying within the vessel walls themselves. Ultrastructural analysis revealed that many synovial plasma cells were considerably larger than plasma cells of a normal size and possessed a marked distension of the cisternae of rough endoplasmic reticulum. Furthermore, plasma cells in close proximity to blood vessels often appeared to be undergoing migration. These observations imply that in rheumatoid synovium, plasma cells are metabolically very active and occupy a pivotal position for the secretion of antibodies into both the vascular and the extravascular compartments.

Aged

A comprehensive electrophysiological evaluation of phrenic nerve injury related to open-heart surgery.

A prospective electrophysiological study of phrenic nerve was performed in 59 subjects undergoing open-heart surgery. The nerve was stimulated percutaneously at the neck and the diaphragmatic response was recorded with surface electrodes placed over the 8th intercostal space. The latency, amplitude, duration and area of the evoked response were measured before and after the operation. Post-operatively no response was elicited in 2 patients bilaterally, in 5 from the left and in 2 from the right. Comparison of the post-operative with the pre-operative group values in the remaining subjects showed that the amplitude and area of the left phrenic were lower in the post-operative study, indicating that some of the nerve fibres were not conducting. There were no statistically significant differences between pre and post-operative values of latency or duration on the left or any of the parameters on the right. Our findings suggest that the amplitude and area of the diaphragmatic response are more sensitive than latency in detecting phrenic nerve paresis associated with open-heart surgery.

Aged

Efficacy of a third coronary angioplasty for a second restenosis: short-term results, long-term follow up, and correlates of a third restenosis.

OBJECTIVE: To report on the short-term and long-term results of patients who underwent a third coronary balloon angioplasty for a second restenosis and to identify the correlates of a third clinical restenosis. DESIGN: A retrospective analysis of clinical, angiographic, and procedure related variables of a consecutive series of patients. PATIENTS: 62 patients (mean (range) age 53 (31-72) years; 84% men) who underwent a third coronary balloon angioplasty of a single coronary artery segment at which restenosis had occurred after two previous angioplasty procedures between 1986 and 1992. RESULTS: Procedure success was achieved in 56 patients (90%). Complications included one myocardial infarction (2%) and one emergency coronary artery bypass surgery (2%). Complete follow up data were available (median (range) 48 (12-94) months). During the follow up period, four patients (6%) died, two (3%) had a non-fatal myocardial infarction, and five (8%) underwent elective coronary artery bypass surgery. Nine patients (14%) underwent a fourth angioplasty for a third clinical restenosis, and three (5%) had a fourth angioplasty procedure for new coronary lesions. The cumulative probability of survival for all 62 patients was 97% and 95% at 1 and 5 years, respectively. The 1 and 5 year freedom from death, infarction, bypass surgery, and repeat angioplasty was 82% and 66.6%, respectively. At census, of the 58 survivors, 31 (53%) were asymptomatic and only eight (14%) complained of angina grade III or IV (P < 0.001). A third clinical restenosis occurred in 22 (39%) of the 56 patients who had initially successful procedures. Multiple stepwise logistic regression analysis identified the interval between the second and third angioplasty procedure as the only independent predictor of a third clinical restenosis (P = 0.004). CONCLUSIONS: A third coronary angioplasty for a second restenosis can be performed safely and effectively and should be considered as an integral part of the overall coronary angioplasty revascularisation strategy. The incidence of a third clinical restenosis remains high, however, and is correlated with the interval between the previous angioplasty procedures.

Adult

Percutaneous transluminal coronary angioplasty in patients 70 years of age or older: 12 years' experience.

OBJECTIVE: To evaluate the short and long term results of coronary angioplasty in patients aged 70 years and older and identify the determinants of long-term survival. DESIGN: A retrospective analysis of clinical, angiographic, and procedure related variables on a consecutive series of patients. PATIENTS: 163 patients aged 70 years and older (mean (range) age 73 (70-83) years; 63% men) who underwent a first coronary angioplasty procedure between 1981 and 1993. RESULTS: Procedural success was achieved in 82% of patients. Four patients (2%) died, three (2%) had a myocardial infarction, and five (3%) underwent emergency coronary artery bypass surgery. Complete follow up data were available for all patients (median (range) 35 (2-146) months). During the follow up period 16 patients (10%) died, two (1%) suffered non-fatal myocardial infarction, and 12 (7%) underwent elective coronary artery bypass surgery. A second angioplasty procedure was performed in 24 patients (15%). The cumulative probability of survival was 90.7% at 1 year and 83.4% at 5 years. Survival free from myocardial infarction, bypass surgery, and repeat angioplasty at 1 and 5 years was 68.2% and 56.0%, respectively. Proportional hazards regression analyses identified incomplete revascularisation as the only independent predictor of poorer overall survival (P = 0.04) and event free survival (P < 0.001). At census, of the 143 survivors, 75 (52%) were asymptomatic, 58 (41%) had mild angina, and only 10 (7%) complained of grade III or IV angina. Some 112 patients (78%) improved by at least two angina grades. CONCLUSION: Coronary angioplasty can be performed safely in the elderly and provides good symptomatic relief and favourable long-term outcome. Complete revascularisation may not be necessary if the primary goal is to achieve symptomatic relief, but incomplete revascularisation is associated with poorer long-term survival.

Aged

Application of an immortalized human endothelial cell line to the leucocyte:endothelial adherence assay.

This report shows that an immortalized endothelial cell line (EA.hy 926) is able to substitute for secondary cultures of human umbilical vein endothelial cells (HUVEC) in the leucocyte:endothelial adherence assay. Enriched preparations of blood polymorphonuclear leucocytes, monocytes and resting and activated lymphocytes exhibited similar adherence characteristics to HUVEC and the EA.hy 926 cells. Cytokines such as tumour necrosis factor (TNF) act on endothelial cells to increase their adhesiveness for leucocytes and in this study there was no difference between TNF-treated HUVEC and EA.hy 926 cells in supporting the enhanced binding of leucocytes. The adherence promoting effect of TNF-treated EA.hy 926 cells appears to be dependent upon their endothelial properties since TNF treatment of A549 cells, the permanent human cell line used to generate the hybrid EA.hy 926 cells did not augment lymphocyte attachment. Monoclonal antibodies against CD11a and CD18 inhibited the binding of lymphocytes to untreated and TNF-treated HUVEC and EA.hy 926 cells and ICAM-1 expression was increased on both monolayers following treatment with TNF. The availability of a hybrid endothelial cell line whose adhesive properties are similar to those of recently isolated endothelial cells should benefit the study of factors that govern leucocyte-endothelial cell interactions and be advantageous to the longitudinal investigation of leucocyte adherence under static conditions.

Antigens, CD

Assessing long term backache after childbirth.

OBJECTIVES: To investigate the factors associated with long term backache after childbirth, to assess all women reporting new onset long term backache, and to investigate any relation with pain relief in labour. DESIGN: Data collected from obstetric records and postal questionnaires or telephone interviews on morbidity after childbirth from all women delivering their first baby between March 1990 and February 1991, followed by analysis of data collected from outpatient consultations. SETTING: St Thomas's Hospital, London. SUBJECTS: Questionnaires were sent to 1615 women who had delivered their first baby in the defined period; 1015 either replied by post or were contacted by telephone. RESULTS: 299 women (29.5% of responders) reported backache lasting more than six months and of these 156 (15.4%) said they had had no back problems previously. Those women who had received epidural analgesia in labour were significantly more likely to report new onset backache (17.8%; 95% confidence interval 14.8% to 20.8%) than those who did not (11.7%; 8.6% to 14.8%). Younger women, unmarried women, and those reporting other antenatal symptoms were significantly more likely to report new long term backache. The 156 women reporting new backache were asked to attend an outpatient clinic and 36 (23%) did so. The majority had a postural backache which was not severe. Psychological factors were present in 14 women. CONCLUSIONS: Though new long term backache is reported more commonly after epidural analgesia in labour, it tends to be postural and not severe. There were no differences in the nature of the backache between those who had or had not received epidural analgesia in labour.

Adult

Environmental factors predicting nephritis in systemic lupus erythematosus.

OBJECTIVES: To evaluate social class, ethnic origin, and various endocrine variables as potential risk factors in the development of nephritis in patients with systemic lupus erythematosus (SLE). METHODS: A cross-sectional survey was carried out of all outpatients with SLE attending the lupus Clinic of St Thomas's Hospital from March to October 1992 using retrospective survival data. The main outcome measure was the duration of SLE before the onset of nephritis. RESULTS: Two hundred and ninety six women and 11 men were studied; the male patients were excluded from the analysis. Univariate analysis showed an increased risk of nephritis in patients with SLE of West Indian origin with 54 v 19% with nephritis at five years, in patients of lower social class, in patients who did not drink alcohol, and in those with a history of fetal loss after the onset of lupus. No significant effect of the age of onset of SLE, use of oral contraceptives, normal pregnancy, or smoking was seen. Multivariate analysis showed that ethnic origin did not influence the risk of nephritis independently of social class. CONCLUSIONS: Factors associated with socioeconomic deprivation may increase disease severity in patients with SLE.

Abortion, Spontaneous

The immunogenetics of early nephropathy in insulin-dependent diabetes mellitus: association between the HLA-A2 antigen and albuminuria.

One-hundred and seventy-two normotensive, insulin-dependent diabetic patients without clinical proteinuria (Albustix negative) were typed for the major histocompatibility complex class I (HLA-A, -B) and class II (HLA-DR) antigens. Urinary albumin excretion was measured as the albumin:creatinine ratio (UA/UC, mg/mmol) in an early morning sample. Patients expressing the HLA-A2 antigen had significantly higher UA/UC values than those not expressing the antigen. The observed ratio of geometric means was 1.77 (95 per cent confidence interval (CI) 1.18-2.67; p < 0.01); the relative risk of microalbuminuria (UA/UC > 3.0 mg/mmol) associated with expression of HLA-A2 was 2.52 (95 per cent CI 1.11-5.73; p < 0.05). There was no significant association between UA/UC and HLA-B8, -B15, -DR3, -DR4 or other antigens. Patients were re-studied after a mean period of 5.3 years: multiple linear regression analysis showed that the UA/UC at this time was positively related to the initial glycosylated haemoglobin level (p < 0.01) and expression of the HLA-A2 antigen (p < 0.05), but not to blood pressure or creatinine clearance. Fifteen patients developed macroalbuminuria at follow-up (UA/UC > 45.5 mg/mmol). Compared with a group matched for age, sex, duration of diabetes, and glycosylated haemoglobin who did not develop macroalbuminuria, macroalbuminuric patients had a higher frequency of HLA-A2 (p < 0.01). The odds ratio of progressing to macroalbuminuria associated with HLA-A2 had a 95 per cent CI of 1.71 to infinity. We conclude that an immunogenetic factor may play a role in the development of early diabetic nephropathy and that the risk associated with expression of the HLA-A2 antigen is independent of metabolic control and blood pressure.

Adolescent

The development of serum-free hormone-supplemented media for primary kidney cultures and their use in examining renal functions.

We have demonstrated the primary kidney cultures and defined medium can be used for several purposes. First, primary kidney cultures can be examined in defined medium to evaluate the physiological significance of studies made with established kidney cell lines. Secondly, new kidney epithelial cell culture systems can be developed, using primary cultures and defined medium. The studies presented here have demonstrated several possible approaches towards these ends. First, a hormone-supplemented serum-free medium (Medium K-1) developed for an established dog kidney epithelial cell line (MDCK) was used to grow primary cultures of baby mouse kidney epithelial cells without fibroblast overgrowth. The primary cultures of baby mouse cells not only grew in response to each of the five supplements in Medium K-1, but also possessed several of the differentiated kidney functions observed in the MDCK cell line. Secondly, defined media were developed for primary cultures of rabbit kidney epithelial cells directly. The rabbit cells were shown to require a different set of supplements than MDCK cells to attain optimal growth. Furthermore primary cultures derived from purified rabbit proximal tubules required a different set of supplements than primary cultures derived from unpurified rabbit kidney tissue. These new primary culture systems should prove invaluable in examining renal transport functions in vitro.

Alprostadil