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Biomedical subjects

J R Jacobsen

Publications and source records attributed to J R Jacobsen.

At least 37 records · Page 2Linked to original sources
PubMed1995

Perinatal outcome after in vitro fertilisation.

A prospective series of 90 consecutive pregnancies (70 singleton, 16 twin and 4 triplet pregnancies) resulting in births of 114 infants after in vitro fertilisation (IVF) at Rigshospitalet were compared to a control group of pregnancies and deliveries in 70 non-IVF infertility patients with singleton pregnancies and 20 women with normal fertility with twin (n = 16) or triplet (n = 4) pregnancies. No differences in the incidence of third trimester pregnancy complications, abnormal fetal karyotypes or malformations were found. The number of women with spontaneous onset of labor and the gestational age at delivery were similar in the IVF and control groups. In singleton deliveries, the birth weight was lower (p < 0.025) in the IVF group (median 3145 g, range 890-4300 g) than in the control group (3399 g, 2592-4850 g), whereas in multiple gestation similar birth weights were found in the IVF and control groups. We conclude that the birth weight in singleton deliveries after IVF is lower than the birth weight in infertility patients treated differently. The cause of this difference remains obscure.

Adult↗
PubMed1994

[Kawasaki disease. Incidence in Denmark during the period 1981-1990].

The aim of the study was to estimate the incidence of Kawasaki's disease and to describe the clinical manifestations and the prognosis of the disease in children in Denmark during the period 1981-1990. In a register of all hospital admissions in Denmark, 99 patients were registered as having Kawasaki's disease. Of those, 89 patients fulfilled the clinical diagnostic criteria. The mean incidence of the ten year period was 1.0 per 100,000 children per year. The incidence of the disease decreased in the age group from zero to seven years after which it was rarely observed. Typical laboratory findings were hypersedimentation, leucocytosis and thrombocytosis. Eight children had cardiomegaly and three had electrocardiographic changes. Echocardiography was performed in 66 patients showing coronary artery aneurysms in nine patients (14%) (six boys and three girls). No further cardiac complications were found.

Adolescent↗
PubMed1994

Antibody catalysis of peptide bond formation.

An antibody generated against a neutral phosphonate diester transition-state (TS not equal to) analog catalyzes the formation of an amide bond between a phenylalanyl amino group and an acyl azide derived from L-alanine. The antibody is selective for L- vs. D-alanine and does not catalyze the hydrolysis of the acyl azide to an appreciable degree. A rate acceleration of 10,000-fold relative to the uncatalyzed reaction is observed. The antibody may achieve its catalytic efficiency both by acting as an entropy trap and by stabilizing the deprotonated form of the amine nucleophile. These experiments constitute a first step toward a general strategy for the generation of sequence-specific peptide ligases.

Alanine↗
PubMed1994

True trisomy 15 mosaicism, detected by amniocentesis at 12 weeks of gestation and fetal echocardiography.

A case of mosaicism of trisomy 15, with two-thirds of the cells trisomic, was detected at 12 weeks of gestation in amniotic fluid cell cultures obtained with the filtration technique. Ultrasound examination at 13 weeks showed a nodule protruding into the amniotic cavity which was speculated to be remnants of a co-twin, causing the trisomic cell line. At 20 weeks of gestation, a malformation scan (level III) was normal, but supplementary fetal echocardiography revealed a severe cardiac defect (mitral atresia and a ventricular septal defect). Fetal lymphocytes obtained by cordocentesis showed trisomy 15 mosaicism, but only in 5 per cent of the mitoses. After termination, the same percentage of trisomy 15 mosaicism was found in cells from skin and tendon as in the original early amniocentesis. No sign of earlier twinning was found in the placenta or membranes. We conclude that mosaicism in early amniotic fluid obtained by the filter technique in this case reflected the true karyotype accurately and that supplementary echocardiography added significantly to the interpretation of the clinical implications.

Adult↗
PubMed1992

An efficient antibody-catalyzed aminoacylation reaction.

An antibody generated against a neutral phosphonate diester transition-state analog was found to catalyze the aminoacylation of the 3'-hydroxyl group of thymidine with an alanyl ester. A comparison of the apparent second-order rate constant of the antibody-catalyzed reaction [5.4 x 10(4) molar-1 minute-1 (M-1 min-1)] with that of the uncatalyzed reaction (2.6 x 10(-4) M-1 min-1) revealed this to be a remarkably efficient catalyst. Moreover, although the concentration of water (55 M) greatly exceeds that of the secondary alcohol, the antibody selectively catalyzes acyl transfer to thymidine. The antibody exhibits sequential binding, with Michaelis constants of 770 microM and 260 microM for acyl acceptor and donor, respectively, and a dissociation constant of 240 pM for hapten. This antibody-catalyzed reaction provides increased insight into the requirements for efficient aminoacylation catalysts and may represent a first step toward the generation of "aminoacyl transfer RNA synthetases" with novel specificities.

Acylation↗
PubMed1992

Bacterial endocarditis in children: trends in its diagnosis, course, and prognosis.

In a population-based study of 41 children with bacterial endocarditis (BE), diagnosed in the period 1970 through 1989 in eastern Denmark, we analyzed trends in the diagnosis of BE and in mortality, and searched for possible prognostic factors. During this period the delay in diagnosis from first symptom to treatment did not change, but the delay from admission to treatment was significantly prolonged from 0 to 3 days, despite the introduction of echocardiography (ECHO). There was a significant improvement in the prognosis, the mortality rate having decreased from 40 to 0% [95% confidence limits: 12-74 vs. 0-26 (0.01 less than p less than 0.02)]. The improved prognosis was not explained by changes in the etiology or pattern of antibiotic resistance and may reflect a milder course of BE in children. Children with "mild anomalies"--such as bicuspid aortic valve (n = 5), coarctation of the aorta (n = 2), and prolapse of the mitral valve (n = 2)--had a significantly poorer prognosis than children with other forms of congenital heart disease (CHD) (p = 0.004), a reminder of the importance of suspecting BE in all children with unexplained long-lasting or intermittent fever, because some may have unrecognized "mild" CHD.

Child↗
PubMed1992

Aneurysm of the ductus arteriosus in the neonate: three case reports with a review of the literature.

Ductus arteriosus aneurysm was demonstrated in three neonates by echocardiography. One case was already diagnosed in utero. One patient needed surgical resection, whereas in one case the aneurysm of the ductus arteriosus regressed spontaneously. In the third case the patient died of associated lesions. In a review of the literature, 61 previous cases of ductus aneurysm in infants less than 2 months were found. Ductus arteriosus aneurysm may be diagnosed by echocardiography both pre- and postnatally. A ductus aneurysm should be monitored closely by echocardiography. Since a high incidence of complications is reported, surgical resection is indicated if the aneurysm does not regress within a few days.

Adult↗
PubMed1992

Fluorescence probes in biochemistry: an examination of the non-fluorescent behavior of dansylamide by photoacoustic calorimetry.

Photoacoustic calorimetry is shown to be a simple, precise, and accurate method for the quantification of the photophysics of a fluorescence probe, e.g., dansylamide, in a variety of solvents. This technique, which is described in detail, provides a direct measurement of the energy that is released nonradiatively following photostimulation, and can therefore be used to indirectly determine the amount of energy released via luminescent pathways. Photoacoustic calorimetry combined with established absorption and fluorescence methodologies provides a complete arsenal for characterizing the photophysical properties of many systems. Comparison of the photoacoustic signal for dansylamide versus standard compounds (ferrocene, tetraphenylethylene, 8-anilinonaphthalene-1-sulfonate, and/or 5,5'-dithiobis(2-nitrobenzoic acid) in 12 different solvents gave fh values (fraction of each absorbed 337.1-nm photon returned as heat) from a low of 0.530 in 1,4-dioxane to a high of 0.973 in water. The trend noted with solvent polarity is different and more revealing than that determined by the more classical approach of examining either the wavelength of the emission maximum or the fluorescence quantum yield.

Calorimetry↗
PubMed1989

[Percutaneous pulmonary balloon valvuloplasty in Denmark].

Percutaneous balloon valvuloplasty of valvular pulmonary stenosis (PPB) was carried out for the first time in 1982 and is now regarded as the primary method of treatment of this condition. The results of the first PPB treatments in Denmark are presented here. PPB was planned in 28 patients and was carried out in 25 (22 children and 3 adults). PPB was carried out on two occasions in one patient. Twenty-three patients had isolated valvular pulmonary stenosis and two patients had Fallot's anomaly. No complications of significance occurred after the treatments. The average gradient for all dilatations was 77 +/- 24 mm Hg prior to and 36 +/- 23 (p less than 0.0001) immediately after PPB. The gradient was reduced by more than 50% in 68% of the patients. In 14 patients, the gradients over the pulmonary valve was measured by Doppler technique or by cardiac catheterization greater than 6 months after PPB. In these patients, the average gradient was 69 +/- 21 mm Hg prior to PPB, 29 +/- 12 mm Hg (p less than 0.0001) immediately after PPB and 27 +/- 9 mm Hg (p less than 0.0001) at the most recent control examination, on an average 12 months (range 6-24 months) after PPB. In the same patient group, significant reduction of the electrocardiographic right-sided hypertrophy was found at the most recent control examination. It is concluded that PPB is an effective and safe treatment of valvular pulmonary stenosis.

Adolescent↗
PubMed1989

[Prenatal detection of congenital heart disease].

Foetal echocardiography is a sensitive and specific method of investigation for prenatal detection of cardiac malformations. Experience has shown that brief echocardiographic screening can demonstrate, directly or indirectly, the presence of or probability of serious cardiac disease in the foetus as early as the 18th-20th weeks of pregnancy. The method of examination and its limitations are mentioned and it is recommended that screening should be carried out as part of other forms of obstetric ultrasonic scanning. Early prenatal diagnosis of severe structural cardiac malformations provide the possibility for selective termination of pregnancy, optimal pre- and perinatal observation and treatment. The possibility of prenatal diagnosis of serious cardiac malformations increases the value of obstetric ultrasonic scanning and may be included among the advantages of offering this form of investigation to all pregnant women.

Echocardiography↗
PubMed1989

[In vitro fertilization and embryo transfer. 2. The first 44 deliveries of 55 infants].

During the period 1.9.1985-21.2.1988, 143 patients commenced and completed treatment with in vitro fertilization and embryo-transfer (IVF-ET) in Rigshospitalet, Copenhagen. Forty-four out of the 143 patients were delivered of a total of 55 infants. There were 35 single deliveries, seven twin deliveries and two triplet deliveries. Seven women were admitted with threatened abortion and three women developed preeclampsia, one of these was severe. On an average, the deliveries occurred in the 38th week of pregnancy and the average weight of the singletons was 3,020 g. Ten women were delivered preterm and seven of the singletons had birth weights under 2,500 g. The frequency of caesarean section was 34% for singleton deliveries and 43% for all of the deliveries. Thirty-one boys and 24 girls were delivered, all of whom had normal karyotypes. One infant had a cleft lip but no other malformations. Three premature infants required brief respirator treatment. All of the infants were thriving on discharge. This material is still too limited to permit drawing of definite conclusions but it suggests, however, just as in other IVT-ET investigations, that the infants are born slightly earlier and weigh slightly less than average neonates, but that they are otherwise normal. In order to illustrate these problems further, the authors have commenced a more extensive prospective investigation with matched control persons.

Denmark↗
PubMed1989

[Pulmonary hypertension in children treated with ventriculo-atrial shunt in hydrocephalus].

Four infants treated with ventriculo-atrial shunt for hydrocephalus developed sudden pulmonary hypertension, several years after the first operation. All infants died in spite of replacement of the distal shunt and AK treatment. At necropsy, old microemboli were found in the small lung vessels in two infants whereas the two other infants were suspected of having the same lesions from clinical investigations. The overall frequency for this complication was estimated to be 6.7% (95% CI 1.4-14.3%).

Arteriovenous Shunt, Surgical↗
PubMed1988

Long-term follow-up of right ventricular function after Mustard operation for transposition of the great arteries.

As development of right ventricular (RV) failure is a potential risk after Mustard operation for transposition of the great arteries, 17 patients were reexamined 5-13 years postoperatively. Comparisons were made with healthy controls. There were no clinical signs of heart failure. Echocardiographically determined RV end-diastolic diameter was increased to 2.5 +/- 0.8 cm (controls: 1.5 +/- 0.4 cm, p less than 0.001). Comparison of RV systolic time intervals (STI) in patients with normal left ventricular (LV) STI revealed decreased RV function, with RPEPI 165 +/- 19 msec (controls 126 +/- 12, p less than 0.001) and RPEP/RVET 0.484 +/- 0.096 (controls 0.284 +/- 0.045, p less than 0.001). Nuclear angiography demonstrated decreased RV ejection fraction (EF), viz. 42.8 +/- 6.6% (normal RV 53 +/- 6%, LV 68 +/- 9%, p less than 0.001). Only two patients showed normal (5%) rise in RV-EF during exercise. There was no evidence of deterioration with passage of time. The results do not justify use of anatomic repair at our center, since the perioperative mortality might then be higher than in the Mustard or Senning procedures.

Angiography↗