Search PubMed⌕ Search

Biomedical subjects

M Jensen

Publications and source records attributed to M Jensen.

At least 145 records · Page 8Linked to original sources
PubMed1981

Rat trophoblastic cell antigenicity.

Trophoblast cells were isolated from the trophoblast giant cell (TGC) layer associated with the rat parietal yolk sac and from the chorioplacenta. Antisera to these cells were produced in the rabbit and analysed with several test systems. Anti-TGC sera reacted with Reichert's membrane (RM), TGC, and chorioplacental trophoblast cells (CTC) by immunodiffusion, and immunofluorescent localization showed that antisera produced against both preparations of trophoblast cells reacted with antigens present in RM and the maternal and renal glomeruli. There was no localization in the trophoblast cells themselves. The abortifacient effects of trophoblastic antisera, which were previously reported, were not found to be due to antisera produced to specific antigens of the trophoblastic preparations which were utilized. In fact the only abortigenic effect observed could be eliminated if the TGC antisera were absorbed with RM. There are several possibilities to explain the presence of antigens in the TGC and CTC which cross-react with RM, and these are discussed, but it is important to recognize that, in the rat, the preparations of antisera to TGC and CTC may produce abortigenic and embryotoxic effects by their actions not on the chorioplacenta, but on the yolk sac placentae. Both the previous reports of embryotoxicity of trophoblastic antisera and our own findings only raise many new questions that have obviously not been answered by this study. But these studies make it quite apparent that any immunological, embryotoxic or teratological studies in the rodent that deal with antigens of the chorioplacenta must include simultaneous immunological and biological studies involving the yolk sac placentae, since dysfunction in either of these placentae can result in various types of reproductive failure.

Animals↗
PubMed1980

Structural studies on the glucose-heptose region of the Proteus mirabilis R core.

Methylation analysis of the core oligosaccharide of the Proteus mirabilis mutant R4 (derived from serotype 028 was carried out in order to obtain information on the internal (glucose-heptose) region of the P. mirabilis R core. The isolated core oligosaccharide was composed of glucose, L-glycero-D-manno-heptose, 3-deoxy-D-manno-octulosonic acid (dOclA) and phosphorus in a molar ratio of about 1:2:1:1.4. It was methylated either directly or after dephosphorylation. To localize the position of the phosphate substituents, the permethylated product was dephosphorylated with hydrogen fluoride and the oligosaccharide obtained was remethylated using C2H3I. Location of phosphate at C-7 of the terminal heptose was shown by isolation of the sugar phosphate from partial hydrolysates and gas-liquid chromatography/mass spectrometry of the permethylated product. Combining the data of the methylation analysis with the data of an NMR study allows one to formulate the structure of the core oligosaccharide as folllows: (formula: see text).

Carbohydrate Conformation↗
PubMed1979

Prenatal diagnosis of beta-thalassemia.

Prenatal diagnosis was attempted in 14 fetuses at risk for homozygous beta-thalassemia, gestational age 18-22 weeks. In 4 cases the placenta was entirely anterior, placental aspiration under ultrasonic control only had to be used for fetal blood sampling. In 10 fetuses fetoscopy was used for puncture of a chorionic blood vessel. Diagnoses were based on the rate of in vitro synthesis of beta-globin related to total non-alphaglobin synthesis. With the aid of fetoscopy, nearly pure fetal blood was obtained in general. Placental aspiration resulted in samples which contained a low percentage of fetal and a high percentage of maternal cells. The attempt of fetal blood sampling resulted in fetal loss in two cases. In 2 aspiration cases no diagnosis could be made because the samples were inadequate. In 2 cases the diagnosis was established in spite of low fetal cell content through determination of the specific radioactivity in the placental and pure maternal blood. Until now 6 children have been born in whom prenatal diagnosis had been attempted, none of them has homozygous thalassemia. Present efforts are directed toward improving the safety of fetal blood sampling and the biochemical methods for the diagnosis in placental samples with low fetal cell content. Although the prenatal diagnosis of beta-thalassemia is possible, the procedure has still to be considered experimental.

Female↗
PubMed1979

Infant nutrition.

Explore the source record for details and available documents.

Blood Glucose↗
PubMed1978

Prenatal diagnosis of beta-thalassemia using selective hemolysis of maternal cells contaminating fetal blood sample.

The prenatal diagnosis of the severe, hereditary anemias may be impossible when a placental blood sample which contains a high percentage of maternal rather than fetal cells is obtained. An incubation system described by Boyer et al. [3] with minor modifications, was applied to mixtures of blood from prematures and adults in order to increase the proportion of premature cells. After 40 min incubation, 95% or more of adult red cells were destroyed, whereas 30-60% of premature red cells were recovered, as determined by several independent methods. In a pregnancy at risk for beta-thalassemia, a placental blood sample which was purely fetal was obtained. Complete lack of in vitro beta-globin synthesis showed the fetus to have homozygous beta-thalassemia. When fetal blood was mixed with maternal blood in a ratio of 1:15, beta-globin synthesis in the mixture was comparable to that of normal fetuses. In contrast, when the cell mixture was subjected to selective hemolysis prior to separation of globins, beta-globin synthesis again was not detectable. Thus, using selective hemolysis, the correct diagnosis could be established from a blood sample containing only about 6% of fetal cells.

Female↗
PubMed1978

Peroperative haemorrhage and epidural anaesthesia in major abdominal surgery. A retrospective study.

The preoperative blood loss during resection of the colon, abdominal-perineal excision of the rectum and cystectomy, according to the method of Bricker, was studied from anaesthetic reports. The period under study was 18 months. A total of 97 patients were divied into two main groups according to the type of anaesthesia (general anaesthesia and general anaesthesia combined with epidural analgesia), as well as into sub-groups according to the type of operation. An evaluation was made of the blood loss, peroperative mean arterial blood pressure and the duration of the operation. In contrast to reports published earlier on other types of operation, we have been unable to demonstrate a significant reduction in the blood loss of patients given general anaesthesia plus epidural analgesia, despite a lower mean arterial blood pressure during the operation. We ignored any possible postoperative beneficial effect of epidural anaesthesia.

Abdomen↗
PubMed1978

Numerical assessment of bone scintigraphy in primary bone tumors and tumor-like conditions.

Fifty-four tumors or tumor-like conditions in bone were studied by numerically assessed 99m-technetium polyphosphate scintigraphy. The uptake was expressed as a ratio of the uptake in the tumor region to the uptake in a corresponding region in the contralateral part of the body. In the malignant tumors there was marked variation in the uptake within each individual tumor group, a variation that rendered a differential diagnosis impossible. In general, the uptake was fairly high in malignant tumors and lower in benign ones. A ratio below 1.5 suggested the likelihood that the lesion was benign. The ratios also varied considerably with the site of the tumor and the patients' ages. Relatively low ratios were found for tumors of the trunk and for juxta-articular tumors in children, whereas higher and more varied ratios were observed in tumors of the peripheral skeleton in adults. It is concluded that numerically assessed scintigraphy is not a useful supplement to other methods used for diagnosing bone tumors.

Adolescent↗
PubMed1977

Axillary micrometastasis and macrometastasis in carcinoma of the breast.

A retrospective analysis was made of 105 patients with primary operable carcinoma of the breast with positive axillary nodes who had been observed for a 14 year period after radical mastectomy. Patients with micrometastasis alone, especially if only level I is involved, have a good prognosis with 85 and 77 per cent survival rates at ten and 14 years, respectively. No patients had more than three micrometastasis. Patients with four or more positive nodes have a much worse prognosis than do those with three or less positive nodes. Macrometastasis at any level carries a poor prognosis. Since these data show no significant difference between the ten and 14 year survival rates, the ten year survival rate is, therefore, a valid one for long term evaluation of the treatment of carcinoma of the breast.

Adult↗
PubMed1977

Morphologic alterations in the parietal yolk-sac of the rat from the 12th to the 19th day of gestation.

The rat parietal yolk-sac and its adherent epithelial cells were examined at various stages of gestation using an en face technique. Specimens were observed a both the light and electron microscopic level. Diastase pretreatment and PAS-staining were used to determine the presence of glycogen. As early as the 12th day of gestation the cytoplasm of the parietal yolk-sac cells contained numerous ribosomes and mitochondria and a large amount of endoplasmic reticulum. The glycogen content of the epithelial cells increased from the 12th day of gestation and accumulated in large quantities by the 16th day. By the 17th day many cells exhibited variable degrees of degeneration. Cellular elements of degenerating cells appeared to be trapped within Reichert's membrane. Contrary to the reports of other investigators, the present study indicates that the capsular portion of the parietal yolk-sac consisting of Reichert's membrane and its adherent epithelial cells remained intact until at least the 18th day of gestation. Some of the unique characteristics of the parietal yolk-sac provide experimental models to study the effects of environmental factors on (1) the synthesis of basement membranes, (2) the ageing of cells and (3) the correlation of these histologic changes with the functions of the parietal yolk-sac.

Animals↗