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Biomedical subjects

M B Jensen

Publications and source records attributed to M B Jensen.

11 recordsLinked to original sources
PubMed1992

[Pulmonary arteriovenous malformations and fistulas].

Pulmonary arteriovenous malformations are often associated with the Rendu-Osler-Weber-syndrome (40-65%) and involve high risks of serious complications, especially of cerebral character. Operative treatment minimizes morbidity and mortality, but presents problems in cases with multiple, bilateral lesions. Embolotherapy seems promising as an alternative to surgery in cases of widespread lesions. Based on the literature, active therapy is recommended to all patients with pulmonary arteriovenous malformations and fistulas. The only exception may be asymptomatic patients with small lesions who have no evidence of the Rendu-Osler-Weber-syndrome.

Arteriovenous Fistula↗
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↗
PubMed1991

Aneurysm of the ductus arteriosus. A review of the literature and the surgical implications.

One hundred and forty-four cases of aneurysms of the ductus arteriosus (DAA) have been reported in the literature of which 106 appeared spontaneously and 38 followed surgical treatment of a patent ductus arteriosus (PDA). Within the last few years there has been an increasing number of reported spontaneous DAA. However, the real incidence is presumably still underestimated. Aortography is a well established diagnostic method. In neonates, transthoracic echocardiography has shown convincing potential, whereas in older children and adults, transoesophageal echocardiography has yielded very promising results. Serious complications following spontaneous DAA are rupture, erosion, infection and thromboembolism. In infants younger than 2 months of age, the complication rate is 31%, in children between 2 months and 15 years, 66%, in adults, 47%. The rate of complications following postoperative DAA is even higher: 91% of the unoperated cases died due to rupture or infection. The operative mortality in children older than 2 months and adults is low. In the neonate group, 2 of 8 died during operation. The operative mortality in patients with postoperative DAA was 26%. Based on information from the literature, we suggest prompt surgical treatment of all spontaneous DAA in patients older than 2 months of age, and in all patients with postoperative DAA. In infants, a DAA should be closely followed with echocardiography, as spontaneous regression has been reported in this age group. If no regression is seen within a few days, it should be surgically corrected.

Adult↗
PubMed1991

A double staining technique for simultaneous demonstration of astrocytes and microglia in brain sections and astroglial cell cultures.

We developed a double staining technique for simultaneous demonstration of astrocytes and microglial cells in histological brain sections and cell cultures. The procedure included a histochemical stain specific for microglial cells and an immunocytochemical stain specific for astroglial cells, with postponement of the final visualization of the staining products until both reactions had been performed. First, microglial cells were specifically but invisibly labeled by histochemical reaction for nucleoside diphosphatase (NDPase). Then the astroglial cells were labeled by performing the first parts of the immunocytochemical reaction for glial fibrillary acidic protein (GFAP). Finally, in a series of intervening steps, the NDPase reaction product was visualized and stabilized by treatment with ammonium sulfide and silver nitrate, while the 1-naphthol basic dye method was used to visualize the GFAP immunoreactive product. As an end product, the NDPase-positive microglial cells were brown and the GFAP-reactive astroglial cells blue. The two types of glial cells were clearly distinguishable in vibratome sections of rat brain tissue and in primary astroglial cell cultures, and we never observed cells that stained for both NDPase and GFAP. When the GFAP antibody was replaced by the OX-42 antibody, which recognizes microglial cells and macrophages, double staining of microglial cells was observed. The staining protocol has wide applications in studies of the functional interactions between microglial and astroglial cells in the normal brain and in different pathological states with neuronal or axonal degeneration, just as it can be used for experimental studies in cell cultures.

Acid Anhydride Hydrolases↗
PubMed1990

Induction of cytochrome P450IA1 in rat colon and liver by indole-3-carbinol and 5,6-benzoflavone.

It is known that consumption of cruciferous vegetables protects against the chemical induction of cancer in many organs. It has been suggested that this protection is mediated through an effect on the cytochrome P450 monooxygenase system. This system is responsible for the activation of a number of chemical carcinogens to their ultimate forms. In the present study, the effect of indole-3-carbinol (I3C) and 5,6-benzoflavone (5,6BF) on the expression of cytochrome P450IA1 in rat colon and liver has been investigated. Cytochrome P450IA1 mRNA was induced in colon following a single oral administration of I3C or 5,6BF. A biphasic induction profile was obtained with maxima at 4 and 16 h post-administration. Both inducers caused an approximately 2-fold increase in P450IA1 mRNA at 4 h and a 10-fold increase at 16 h. In contrast, both cytochrome P450IA1 and IA2 mRNAs was increased over the control between 4 and 24 h. The total amount of P450IA mRNAs in liver at 4 and 16 h was increased about 2- and 4-fold respectively by I3C; 5,6BF induced the P450IA mRNAs 4- and 5-fold respectively. The expression of cytochrome P450IA1 and IA2 is induced by I3C and several flavones present in cruciferous vegetables. This suggests that one of the protective effects of cruciferous vegetables in the reduction of chemically induced cancer may be regulation of cytochrome P450s involved in the metabolism of the chemical carcinogens.

Animals↗
PubMed1989

Isolation of cardiac ventricular myocytes from newborn rats by use of fractional elutriation centrifugation.

Isolation of cardiac ventricular myocytes from newborn rats (0-4 days old) by use of elutriation centrifugation is described. By the use of fractional centrifugation, a homogeneous myocyte population with high purity was obtained without any further procedures, yielding about 10(6) myocytes/rat. When 48-hr monolayer cultures were established, the cells showed normal pulsatory contractions. A morphological evaluation of such cultures is given.

Animals↗