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Biomedical subjects

A Larsson

Publications and source records attributed to A Larsson.

At least 505 records · Page 28Linked to original sources
PubMed1978

Reversible effects on cellular metabolism and proliferation by trisodium phosphonoformate.

The antiviral compound trisodium phosphonoformate (PFA), which inhibits herpesvirus multiplication by 50% at a concentration of 10 muM, did not show any effects on macromolecular synthesis and cell proliferation in HeLa and human lung cells at this concentration. At the high concentration of 2 mM, PFA reduced DNA synthesis to 50% after 1 h of treatment, whereas no effects could be seen on RNA and protein synthesis. Treatment for 24 h with 1 mM PFA inhibited both DNA synthesis and cell proliferation to 50%. The inhibition of DNA synthesis and cell proliferation at 10 mM PFA was rapidly reversed by removing the drug from the cells.

Antiviral Agents↗
PubMed1978

Concentrations of organic acids in the urine of healthy newborn children.

Urine concentrations of organic acids were determined by a gas chromatographic technique in healthy, full-term neonates at the ages of 2 and 5 days. Significant reductions in the interindividual variation were obtained by relating the levels of organic acids to urine creatinine concentration or osmolality. Citrate was the predominant organic anion found. Urine concentrations of fumarate, 3-hydroxy-3-methylglutarate, adipate, and suberate decreased during the first week of life, and their concentrations were significantly intercorrelated. It is suggested that these findings reflect the predominantly fat-utilising, hyperketonaemic state during the first days of life. The urine concentrations of the aromatic end-products, p-hydroxyphenylacetate and hippurate, increased during the first week of life, probably as an effect of dietary factors. It is concluded that analysis of intermediary organic acids in urine could be of value in the assessment of the metabolic state in neonates.

Aging↗
PubMed1978

No demonstrable accumulation of 14C-vitamin D3 in developing rat teeth and bones.

The distribution of 14C-vitamin D3 administered subcutaneously in arachidic oil to 6-day-old suckling rats has been examined autoradiographically. The animals were sacrificed 1, 2, 4 and 8 days after injection. The autoradiographic exposure time was 4 months. The sectioning and exposure was performed in a freeze-room. Radioactivity was found mainly in the liver, kidney, intestines and fat depots. No uptake was found in developing teeth or bones.

Animals↗
PubMed1978

Benign cementoblastoma--cementum analogue of benign osteoblastoma?

We believe that the current case is a good example of a "borderline lesion" that shows the histologic features of benign osteoblastoma but with some clinical features suggestive of a cementoblastoma, such as attachment to the roots. We suggest, however, that the involvement of the roots should not rule out the diagnosis of benign osteoblastoma. The fact that a benign osteoblastoma may envelop the roots in a way characteristic of a benign cementoblastoma, however, is suggestive of a close relationship between the two tumors.

Adolescent↗
PubMed1978

Ameloblastoma of the jaws. An analysis of a consecutive series of all cases reported to the Swedish Cancer Registry during 1958--1971.

All the 49 jaw ameloblastomas reported to the Swedish Cancer Registry during the period 1958--1971 were re-examined, using the histopathologic criteria of odontogenic tumors adopted by WHO. Thirty-one cases (63.6%) fulfilled the criteria of simple ameloblastoma, whereas 12 cases were found to be other benign lesions and 6 to be malignant tumors other than ameloblastoma. The relationship between simple ameloblastoma, malignant ameloblastoma and other epithelial jaw tumors is discussed.

Adolescent↗
PubMed1977

Pulpal status after autogenous transplantation of fully developed maxillary canines.

By means of histologic and histochemical studies of oxidative enzymes, the pulps of transplanted fully developed maxillary canines have been evaluated after an observation period of 3 to 25 months. No pulp had survived the transplantation trauma, and endodontic treatment of fully developed transplant teeth was considered to be a prerequisite to an optimal clinical result.

Adult↗
PubMed1977

Multiple lesions of the lip exhibiting the "Jadassohn phenomenon". Review of the literature and report of a case.

The clinical and microscopic features of multiple, superficial lesions of the lip and adjacent mucosa in an elderly woman are reported. The lesions had been present for many years apparently without symptoms. A histologically confusing picture gave rise to diagnostic problems. Characteristic nests of basaloid cells were present at all levels of the acanthotic epithelium together with microcysts, horn pearls and squamous cell eddies. Review of the literature revealed no previous report on similar lesions of the oral mucosa and it is suggested that the lesions closely coincide with the Jadassohn type of intra-epidermal epithelioma.

Aged↗
PubMed1977

Inhibition of influenza virus ribonucleic acid polymerase by ribavirin triphosphate.

Ribavirin 5'-triphosphate (RTP), derived from the broad-spectrum antiviral compound ribavirin (Virazole), can selectively inhibit influenza virus ribonucleic acid polymerase in a cell-free assay. Ribavirin and its 5'-monophosphate have no effect on the polymerase. The inhibition is competitive with respect to adenosine 5'-triphosphate and guanosine 5'-triphosphate. RTP also inhibits ApG- and GpC-stimulated influenza virus ribonucleic acid polymerase. Since ribavirin is phosphorylated in the cell, the inhibition of influenza multiplication in the cell may also be caused by RTP.

DNA-Directed RNA Polymerases↗
PubMed1977

The immediate effect of a beta-adrenergic agonist (salbutamol) on carbohydrate and lipid metabolism during the third trimester of pregnancy.

The responses of plasma insulin and the C-peptide of proinsulin, glucose, lactate, free fatty acids (FFA), glycerol, D-beta-hydroxybutyrate and alanine to a beta2-adrenergic agonist (salbutamol) were determined in 5 patients during the last trimester of pregnancy before labor. Salbutamol was given as an infusion in the same dosage as is used to inhibit uterine contractions in cases of premature labor and in obstetric emergencies. The influsion of salbutamol was given for 45 min, accompanied by repeated sampling of arterial blood. All patients developed moderate tachycardia and exhibited metabolic effects following salbutamol infusion, implying marked increases in plasma levels of insulin, C-peptide, glucose and lactate. An increased rate of lipolysis was evident from the rises of FFA, glycerol and D-beta-hydroxybutyrate. Plasma levels of alanine declined, possibly due to stimulation of gluconeogenesis. It is unlikely that these acute maternal metabolic changes would have significant adverse effects on the fetus.

Adolescent↗
PubMed1977

The effects of ethylene-1-hydroxy-1, 1-diphosphonate on the developing mandibular condyle -- a light microscopic study.

The effects of high doses of ethylene-1-hydroxy-1, 1-diphosphonate (EHDP), a potential mineralization inhibitor, were studied in the developing mandibular condyle of the rat. The animals were given one injection of EHDP/day for four consecutive days. One group of animals received 30 mg and another group 50 mg EHDP/day. Animals from each group were killed either the day after or three days after the last EHDP-injection. EHDP-administration resulted in a failure of mineralization of the cartilage and osteoid, a widening of the hypertrophic zone, an appearance of cells in lacunae at the cartilage-methphyseal junction and in an inhibited capillary invasion. There was little evidence of a resumed mineralization in rats left to survive for three days after the last EHDP-injection. The results indicate additional effects of EHDP besides an inhibition of calcium phosphate crystallization, and also that EHDP may be a useful tool in the study of mechanisms of cellular hypertrophy and capillary invasion in mineralizing cartilage.

Animals↗
PubMed1977

14C vitamin A in developing rat teeth and bone. A whole body-autoradiographic study.

The distribution of vitamin A in developing young rats has been studied. Low doses of 14C-retinol were administered intraperiotoneally and the uptake analyzed autoradiographically. The vitamin was found to accumulate mainly in the intestines, liver, kidney, adrenal and brown fat. No uptake could be detected in hard tissue forming cells nor in any hard tissue, except in the secretory ameloblasts of the incisors.

Adipose Tissue, Brown↗
PubMed1977

Distribution of 99Tcm-labelled phosphorus compounds, 45Ca and 85Sr in diphosphonate-treated rats.

A similar distribution of 99Tcm, 45Ca and 85Sr was obtained when injected in rats as 99Tcm-labelled pyrophosphate or ethylene-1-hydroxy-1,1-diphosphonate (EHDP), 45Ca-chloride and 85Sr-choloride respectively. The highest concentrations occurred in bone and teeth. In EHDP-treated rats, isotopes were accumulated at sites of ectopic calcifications in the lung, kidney and stomach wall as well as in mineralized tissues. These results indicate that 99Tcm, when administered as 99Tcm-labelled EHDP accumulates predominatly in the inorganic rather than organic tissue components.

Animals↗
PubMed1976

Erythrocyte glutathione synthetase in 5-oxoprolinuria: kinetic studies of the mutant enzyme and detection of heterozygotes.

The primary metabolic defect in 5-oxoprolinuria is a generalized deficiency of glutathione synthetase. The activity of this enzyme was determined in cell-free extracts of erythrocytes from patients with 5-oxoprolinuria, their parents and a sibling as well as from normal control individuals. The following activities (pkat/mg of hemoglobin) for glutathione synthetase were obtained: homozygotes mean 0.10 (range 0.07-0.12), heterozygotes mean 3.1 (range 2.8-3.7) and control individuals mean 6.1 (range 5.4-6.7). These results indicate that 5-oxoprolinuria, i.e. the defective gluthione synthetase gene(s), is transmitted by autosomal recessive inheritance. Studies of the kinetics of the low remaining activity of erythrocyte glutathione synthetase in patients with 5-oxoprolinuria failed to reveal defective affinity for glycine, gamma-glutamyl-alpha-aminobutyrate, ATP and Mg2+ ions. Furthermore, the pH optimum, time curves and temperature dependence for the mutant enzyme activity did not significantly differ from the corresponding parameters observed with normal enzyme.

Adenosine Triphosphate↗
PubMed1976

On the mechanism of 5-oxoproline overproduction in 5-oxoprolinuria.

The primary metabolic defect in 5-oxoprolinuria (pyroglutamic aciduria) is the lack of glutathione synthetase. The mechanism of the concomitant overproduction of 5-oxoproline was studied using cell-free extracts of erythrocytes from control individuals and from patients with 5-oxoprolinuria. Such extracts catalyzed the synthesis of 5-oxoproline from L-glutamate. Addition of ATP, Mg ions and alpha-aminobutyrate was needed for optimal activity. The conversion of glutamate to 5-oxoproline occurred in two steps, catalyzed by gamma-glutamyl-cysteine synthetase and gamma-glutamyl cyclotransferase, respectively. Extracts of erythrocytes from control subjects and patients with 5-oxoprolinuria had identical capacity to synthesize 5-oxoproline. The conversion of glutamate to 5-oxoproline was markedly inhibited by reduced glutathione, which exerted its effect on the gamma-glutamyl-cysteine synthetase step. The following mechanism is postulated for the overproduction of 5-oxoproline in 5-oxoprolinuria: the deficiency of glutathione synthetase causes a lack of glutathione which is an essential feed-back inhibitor in the initial step of its biosynthesis. Therefore gamma-glutamyl-cysteine is produced in excessive amounts and it is subsequently converted to 5-oxoproline (and cysteine) by gamma-glutamyl cyclotransferase. This overproduction of 5-oxoproline exceeds the capacity of the 5-oxoprolinase and 5-oxoproline accumulates in body fluids.

Amino Acid Metabolism, Inborn Errors↗