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Biomedical subjects

A Amiel

Publications and source records attributed to A Amiel.

At least 91 records · Page 5Linked to original sources
PubMed1992

Placental insufficiency as a possible cause of low maternal serum human chorionic gonadotropin and low maternal serum unconjugated estriol levels in triploidy.

We report three cases in which triploidy (69,XXX) was detected by amniocentesis performed for very low maternal serum human chorionic gonadotropin levels. All three cases also had low maternal serum unconjugated estriol levels. We suggest placental insufficiency as the cause of the very low human chorionic gonadotropin because of histologic observations and because a known marker for placental insufficiency, estriol, was also very low.

Abortion, Therapeutic↗
PubMed1992

[Improvement of the diagnostic value of exercise test by heart-rate adjusted segment depression. Value of ST 20/HR index].

One of the new criteria of positivity of exercise stress testing proposed by Detrano and Kligfield is the ST/HR index, obtained by calculating the ratio of additional ST depression on exercise over the corresponding variation in the heart rate. These authors reported that this ratio improved the diagnostic value of the exercise stress test with respect to the traditional ST segment depression, but that the proportion depended on whether the index was measured 80 or 60 ms after the J point. The object of this study was to assess the diagnostic performance of the ST/HR index measured 0, 20, 40, 60 and 80 ms after the J point by automatic analysis and to compare these five diagnostic indices with the classical ST segment depression (standard criterion) by ROC graphs and the Mac Nemar test. One hundred consecutive patients (73 men and 27 women) all symptomatic, underwent submaximal or symptom-limited exercise stress testing and accepted coronary angiography. The prevalence of greater than or equal to 50% coronary stenosis on at least one main vessel was 48%. None had previous myocardial infarction. The ROC graphs and areas under the curve demonstrated generally the superiority of the ST/HR index over the standard criteria. The optimal diagnostic performance was observed when the index was calculated 20 ms after the J point (ST 20/HR index).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Screening for Down's syndrome in older women based on maternal serum alpha-fetoprotein levels and age: preliminary results.

We report the results of screening for Down's syndrome (DS) in older women using published rate schedules based on maternal serum alpha-fetoprotein (MSAFP) and age. Five hundred and seventeen patients aged 35 years and older, who were referred for a mid-trimester genetic amniocentesis, were first tested for MSAFP and then underwent an amniocentesis. Individual risks for DS, combining MSAFP and age, were derived using three different published rate schedules. Theoretical selection for amniocentesis was made using the cut-off level of the average collective risk for a 35-year-old woman (1:380 at live birth or 1:270 at amniocentesis). Six affected pregnancies (five with DS and one with trisomy 18), which were diagnosed prenatally, were all found to be at a higher risk than the specified cut-off. These cases would have been diagnosed in any event, using any of the published rate schedules. According to these rate schedules, between 39 and 45 per cent of the patients would be in the lower risk group and therefore would have been counselled not to undergo amniocentesis. Further studies should be conducted in order to reach conclusive screening policies for DS in older women.

Adult↗
PubMed1991

Severe non-hypoxic bradycardia during disconnection from the ventilator during the recovery phase of ARDS.

Four patients with adult respiratory distress syndrome developed sinus bradycardia during weaning procedures with no evidence of hypoxemia. Bradycardia occurred immediately after the patients' endotracheal tubes were disconnected from the ventilator and most of the time resolved after reconnection. However, 3 patients eventually deteriorated, requiring advanced life support and for one of them, cardiac pacing. The precise mechanism of these bradycardic episodes remains unclear but was unrelated to hypoxemia or acid-base disorder.

Adolescent↗
PubMed1990

Chromosomal analysis of unfertilized oocytes and morphologically abnormal preimplantation embryos from an in vitro fertilization program.

In vitro fertilization cycles yield a low percentage of pregnancies. Eighty-five to ninety percent of the transferred embryos do not implant, and the abortion rate approaches 30%. Aneuploidy is assumed to be responsible for a major portion of this pregnancy wastage. The purpose of this study was to determine if there was any correlation between morphology and chromosomal content of unfertilized oocytes and rejected embryos. To assess the chromosomal content of oocytes and embryos, we used the method described by Tarkowski in 1966. Sixty oocytes fron 28 women, aged between 27 and 41 years, were analyzed. Sixty-seven percent were aneuploid; of these, 23.35% were hyperhaploid, 23.35% were hypohaploid, 8.35% were hyperdiploid, 3.35% were diploid, and 8.35% showed premature chromosome condensation. Of 20 preimplantation embryos analyzed, 80% were aneuploid, 10% were diploid, 5% were haploid, and 5% showed structural anomaly. Correlation was found between maternal age and aneuploidy in oocytes and between morphology and genetic balance in preimplantation embryos.

Adult↗
PubMed1990

[Critical analysis of the response to antihypertensive therapy. Report of 102 cases].

UNLABELLED: One hundred and two patients with mild to moderate hypertension, non responding to a placebo therapy, were given an antihypertensive drug for a mean period of 6 weeks (range: 3-12 weeks). Their blood pressure (BP) was measured before and after active treatment by both a mercury manometer at the clinic and an ambulatory apparatus (Spacelabs 5200 or 90202). The clinic BP figures were poorly correlated with the 24 hour ambulatory BP levels, as well as the magnitude of decrease in clinic BP with the reduction in ambulatory BP. Twenty eight patients who were considered as "clinic responders" had in fact not significantly lowered their ambulatory DBP and, conversely, 16 patients were "clinic non responders" whereas they were "ambulatory responders". The patients were divided into 2 groups, according to White's and Morgan Roth's recommendations: group I (n = 61) with a percentage of pathological DBP readings (greater than 90 mmHg) during daytime as high as 50% or more, and group II (n = 41) with a percentage less than 50%. The correlations between the 2 methods of BP measurement were closer within the group I than within the group II and the rate of discrepancies between the "clinic" and "ambulatory responders" was lower. On the other hand, we identified the group II patients as being often "clinic responders" but rarely "ambulatory responders", whereas the inverse trend was observed in the group I. IN CONCLUSION: even in non placebo responding hypertensive patients the clinic BP measurement might be not sufficient for proper evaluation of an antihypertensive drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Cellular and molecular characteristics of an immortalized ataxia-telangiectasia (group AB) cell line.

Ataxia-telangiectasia (A-T) is a multisystem hereditary disease featuring neurodegeneration, immunodeficiency, extreme cancer proneness, chromosomal instability, and radiosensitivity. A-T is found in many ethnic groups, and is genetically heterogeneous: four complementation groups have been identified in A-T so far. Attempts to isolate the A-T gene are based in part on gene transfer experiments, using permanent A-T fibroblast lines, obtained by transformation with SV40. "Immortalization" of A-T primary diploid fibroblasts using SV40 is difficult, possibly because of the chromosomal instability of these cells. The number of currently available permanent A-T fibroblast lines is small, and not all of them have been assigned to specific complementation groups. Using the assay of X-ray induced inhibition of DNA synthesis, we have assigned the A-T strain AT22IJE to complementation group AB. Origin-defective SV40 was used to transfect these cells, and one transformant (AT22IJE-T), which survived crisis, was found to have the typical characteristics of permanent cell lines obtained in this way. "In-gel renaturation" analysis did not show any DNA amplification of high degree in AT22IJE-T. Cytogenetic analysis showed considerable chromosomal instability in the new cell line, and medium conditioned by these cells contained the clastogenic activity which is characteristic of the parental strain as well. Other parameters of the "cellular A-T phenotype" have also been retained in the immortalized cells: hypersensitivity to the lethal effects of X-rays and neocarzinostatin, as well as "radioresistant" DNA synthesis. However, the sensitivity of AT22IJE-T to both DNA-damaging agents is less pronounced than that of the parental cells. The capacity of the cells for uptake of foreign DNA was tested by introducing into them the plasmid pRSVneo, using three different transfection methods. Satisfactory frequency of G418-resistant transfectants (0.66%) was achieved using a protocol recently published by Chen and Okayama (Mol. Cell Biol., 7: 2745-2752, 1987), which was found to be superior to the traditional calcium phosphate transfection method and to the polybrene-based method.

Ataxia Telangiectasia↗
PubMed1989

Increased spindle resistance to antimicrotubule agents in cells prone to chromosomal nondisjunction.

The cytological behavior of the spindle apparatus was studied in cells prone to nondisjunction (ND), i.e., PHA-stimulated lymphocytes derived from children suffering from different types of neoplasia. These cells, which exhibited a high frequency of nonspecific aneuploidy, revealed an increased resistance of the spindle fibers to colchicine, podophyllotoxin, and cold, which was several times that of lymphocytes derived from healthy children. The results are in accord with previous findings showing a high resistance of spindle microtubules to the antimicrotubular agents colchicine, podophyllotoxin, vinblastine, and cold in PHA-stimulated lymphocytes derived from individuals prone to meiotic ND. It is therefore assumed that high resistance of the spindle apparatus to antimicrotubule agents characterizes cells at high risk for aneuploidy, and possibly, the overstabilized spindle fibers are responsible for failure of chromosomal disjunction.

Aneuploidy↗
PubMed1989

Ataxia-telangiectasia: a variant with altered in vitro phenotype of fibroblast cells.

The clinical and cellular phenotype of ataxia telangiectasia (AT) has been extensively documented in numerous patients of different ethnic groups and is characterized by several specific laboratory hallmarks, such as chromosomal instability, profound radiosensitivity and radioresistant DNA synthesis. Several recent reports have, however, shown variations on this theme. This article describes 2 Turkish siblings with AT, who showed a typical but somewhat more prolonged clinical course of the disease and altered characteristics of fibroblast cells, compared to the 'classical' AT cellular phenotype. Fibroblast strains derived from these patients showed a normal cellular life span, moderate degrees of chromosomal instability and sensitivity to the lethal effects of X-rays and neocarzinostatin, and lack of radioresistant DNA synthesis. A compilation of the literature on 'AT variants' and 'AT-like' syndromes shows that in addition to the internal variability of AT, this disease occupies a limited segment within a large spectrum of clinical and cellular features, which are common to a variety of syndromes. Each of these syndromes covers a different segment in this spectrum. The genetic basis of this family of disorders might be complex.

Ataxia Telangiectasia↗
PubMed1989

[Blood pressure response to antihypertension treatment. Comparison of data obtained at the doctor's office and by ambulatory blood pressure measurement].

A comparative study of clinical and ambulatory responses to antihypertensive treatment was conducted retrospectively in 69 patients with mild to moderate arterial hypertension. The patients received different drugs, but blood pressure (BP) was measured by the same methods in each of them. (a) Clinical BP was measured with a mercury manometer some time after taking the last dose of antihypertensive drug: 24 hours in patients who took one daily dose, 12 hours in those who took two daily doses. (b) Ambulatory BP was measured with a Spacelabs SPM 5200 instrument over a minimum of 24 hours. The parameters compared were: (1) BP figures recorded. Correlation was very poor as regards both SBP (r = 0.42 before treatment, r = 0.55 after treatment) and DBP (r = 0.40 and r = 0.46 respectively). The mean BP value was lower in the ambulatory group than in the clinical group (-20/-12 mmHg), the difference being slightly less marked after treatment (-12/-6 mmHg). (2) Degree of absolute reduction of BP induced by treatment. Correlation was very poor between the two methods as regards both SBP (r = 0.46) and DBP (r = 0.49). (3) Proportion of responders and non-responders to treatment, the clinical response being defined as normalization and/or more than 10 p. 100 reduction of DBP, and the ambulatory response as a significant decrease of mean diastolic value over 24 hours. Among the 69 patients studied, there were 51 concordant cases (36 responders, 15 non-responders with the two methods) and 18 discordant cases (10 clinical responders but ambulatory non-responders, 8 clinical non-responders but ambulatory responders).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Left ventricular relaxation and ambulatory blood pressure in mild, untreated arterial hypertension].

Twenty patients with mild, untreated arterial hypertension had ambulatory blood pressure recordings and a digitized echocardiographic study of the left ventricle with measurement of its mass (LVM) and of relaxation parameters. A significant correlation was found between LVM and ambulatory systolic pressure during daytime (r = 0.64; p less than 0.01; n = 20) and during 24 hours (r = 0.79; p less than 0.001; n = 16). One of the relaxation parameters studied, the time taken to reach maximal speed of left ventricular enlargement, was closely related to the diurnal diastolic blood pressure (r = 0.58; p less than 0.01; n = 20), whereas in this population with mild arterial blood pressure none of the parameters was related to the amount of increase of LVM. One may therefore consider the abnormalities of left ventricular relaxation as likely to appear at an early stage of arterial hypertension; their discovery may antedate that of LVM and confirm that the hypertensive disease is real. However, the methodological problems encountered with type of exploration ought to be stressed: left ventricular relaxation is a multifactorial phenomenon, and its echocardiographic approach is subject to many hazards.

Adult↗
PubMed1989

[Anti-arrhythmia efficacy of propafenone per os in the prevention of paroxysmal supraventricular arrhythmia resistant to class Ia agents].

The efficacy of orally administered propafenone in the prevention of paroxysmal supraventricular dysrhythmias (atrial fibrillation, atrial tachysystole, reciprocal tachycardia) resistant to Vaughan-Williams class Ia drugs was investigated in 10 patients. Propafenone controlled dysrhythmia very well in 4 out of the ten patients, and satisfactorily in another one at a dosage ranging from 450 to 900 mg/day in 3 or 4 divided doses; this result was documented using continuous 24 hr. Holter ECG monitoring. Among the 5 clinical failures, 1 patient had atrial fibrillation primarily at night, and another poorly tolerated this agent which led to interrupt therapy.

Administration, Oral↗
PubMed1988

[Left ventricular hypertrophy in hypertensive patients. Ultrasonic and physiopathology: therapeutic implications].

Hypertensive left ventricular hypertrophy can easily be diagnosed by echocardiography. It occurs in 30-50 per cent of hypertensive patients and has recently been shown to be a potent and independent predictor of morbidity and mortality, increasing the risk of sudden death, arrhythmia and severe coronary events. The condition usually presents as concentric left ventricular hypertrophy with symmetrically or asymmetrically thickened ventricular walls, but it may also be found with a dilated cavity. Its presence is a definite indication for active medical treatment. Guidelines for the choice of a particular antihypertensive drug are not yet available. Regression of the hypertrophy seems to be a rational goal of the treatment, but the beneficial effects of such a regression on left ventricular relaxation need further evaluation.

Cardiomegaly↗
PubMed1988

[Comparative effects of pindolol and atenolol on blood pressure and lipids in mild to moderate arterial hypertension].

Twenty-one patients with mild or moderate hypertension were randomised to receive either Atenolol 100 mg (N = 10) or Pindolol 15 mg (N = 11) in a once daily dosage over a two month period. The effects of these two betablockers on the blood pressure and plasma lipid profile were studied. Special attention was paid to the methodology: obese patients (30% over theoretical weight derived from the Lorenz formula) and those with pre-treatment triglyceride levels higher than 1.82 mmol/l were excluded because of the well documented biological instability of such patients. The selected patients were given placebo for two weeks. At the end of the placebo period those subjects whose body weight, total cholesterol, apolipoproteins or triglycerides had varied by more than 10%, 15% and 30% respectively, were also excluded from the study. At the end of the 60 days active treatment period, a comparable fall in the blood pressure was observed in both groups and there was no significant difference in the biological parameters as compared with pre-treatment values. In addition, the cardiovascular risk, evaluated by the B/A1 apolipoprotein ratio, increased in only one patient in the group receiving Atenolol and one patient receiving Pindolol.

Atenolol↗
PubMed1987

[Comparative pharmacoclinical study of 2 beta-blockers: atenolol and betaxolol in slight-to-moderate arterial hypertension].

Sixteen patients with mild to moderate hypertension were randomized to receive either atenolol 100 mg a day (group A: 2 females, 6 males, mean age 42.3 years) or betaxolol 20 mg a day (group B: 8 males, mean age 49.3 years), both drugs given once daily for one month with a wash out on the 5th day. Pretreatment blood pressure was significantly higher in group B than in group A: this disparity, linked with randomization, hampered the comparison of the antihypertensive efficacy of both drugs but not the comparison of their pharmacodynamics. The maximal effect on resting supine blood pressure occurred later with betaxolol (4th day) than with atenolol (1st day), while the effect on peak exercise-blood pressure and heart rate was rapidly maximal (1st day) for both beta-blockers. The duration of the antihypertensive action at rest seemed to be nearly similar, while the effects of betaxolol on exercising heart rate and blood pressure were more prolonged than those of atenolol: on the wash out day, plasma atenolol and betaxolol levels fell in a same way but the increase in peak systolic blood pressure was more marked in group A than in group B, so that the positive correlation we found between the plasma drug levels and the percentage of peak systolic blood pressure reduction, was much closer with atenolol (p less than 0.001) than with betaxolol (p less than 0.05).

Adrenergic beta-Antagonists↗