PubMed Health⌕ Search

Biomedical subjects

S Sjögren

Publications and source records attributed to S Sjögren.

At least 19 recordsLinked to original sources
PubMed1991

Changes induced in growing rat bone by immobilization and remobilization.

We studied changes in bone mass and histology in growing rats after different relatively short periods of immobilization and during subsequent remobilization. Immobilization-induced loss of bone weight is mainly due to mineral losses as indicated by changes in wet weight, ash weight, and calcium content. 45Ca2+ incorporation was found to be decreased in immobilized bones and showed strong dependence upon the age of the rats. Histological examination showed rapid and extensive trabecular bone loss, and external measurements of bone length and diameter confirmed that a substantial part of the decrease in bone mass was due to actual trabecular bone loss and not the reduction of external bone volume. Two of the methods studied, cast immobilization and reversible neurectomy, allow subsequent remobilization and thus enable recovery of the bone to be studied. Bone ash weights were 12.3 +/- 1.12% and 13.1 +/- 1.82% below the control values in the tibia and the femur, respectively, after three weeks of cast immobilization and 12.0 +/- 1.10% and 9.2 +/- 0.90% below after three weeks of immobilization by reversible neurectomy. The bone mineral mass recovered by 40% (p less than 0.053) in the femur and 67% (p less than 0.027) in the tibia during the three weeks' remobilization following one week of cast immobilization, and 62% (p less than 0.001) in the tibia but only 38% (p less than 0.073) in the femur after three weeks of cast immobilization. Mobility of the extremity was restored after three weeks of immobilization by reversible neurectomy, whereupon about half of the lost bone mass was recovered in both the tibia and the femur during six weeks of reinnervation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Regeneration of cranial suture and bone plate lesions in rabbits. Implications for positioning of osteotomies.

The positioning of osteotomies in intramembranous cranial bone was studied by exploring the pattern of bone regeneration in growth areas (the sutural region) as compared to that of the bone plate proper. Trephine defects in the left coronal suture area and the right parietal bone were produced in fifty-nine young rabbits. A pilot study to refine operative and analytical methods comprised 22 animals. The experiments were terminated at one, three, and six weeks after surgery. The bone regenerative response was assessed by x-ray planimetry, plain microscopy, enzyme histochemistry, and fluorescent labelling. Only minor divergences in healing capacity between the two defects were found. No adverse effects on the growth process were indicated. As to clinical management, the findings suggest that osteotomies designed to traverse sutural areas will, under normal circumstances, regenerate in a similar manner and rate to adjoining bone plates.

Acid Phosphatase↗
PubMed1988

Calcitonin gene-related peptide in rat salivary glands: neuronal localization, depletion upon nerve stimulation, and effects on salivation in relation to substance P.

Calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibres occurred predominantly around blood vessels and large ducts and, to a minor extent, around acini and small ducts in the parotid, sublingual and submaxillary glands of the rat. Double immunostaining showed most of the CGRP-containing nerve fibres to contain substance P. However, the vast majority of substance P-immunoreactive periacinar nerve fibres in the parotid and submandibular glands lacked CGRP. After parasympathetic denervation of the parotid gland by section of the auriculotemporal nerve these periacinar substance P-immunoreactive nerve fibres disappeared almost completely, whereas the number of substance P/CGRP-immunoreactive nerve fibres seemed unchanged. After this operation the total amount of substance P in the parotid gland was reduced by about 90% as judged by radioimmunoassay; in denervation experiments the facial nerve was found to contribute to the residual substance P content. In contrast, the contribution of the auriculotemporal nerve to the CGRP content of the gland was small; the reduction in CGRP after section of the nerve was 20%. The facial nerve and the dorsal root nerves (C3 and C4) contributed to the CGRP content with about 50%. The source of the remaining 30% of the parotid gland CGRP is unknown. It is not the sympathetic nerve: sympathetic denervation resulted in a marked increase in CGRP, regardless of whether the auriculotemporal nerve was intact or not. Upon long-lasting electrical stimulation of the auriculotemporal nerve at a high frequency the parotid gland content of CGRP was gradually reduced, indicating depletion of this peptide in response to nerve stimulation. Intravenous injections of CGRP evoked no salivary flow; however, a release of amylase was revealed. Also, when CGRP was tested on isolated parotid gland lobules amylase was released into the medium. When, in vivo, CGRP was injected in combination with substance P, the substance P-evoked flow of parotid and submaxillary saliva was markedly enhanced. In addition, CGRP enhanced the in vivo secretory response to parasympathomimetics and to vasoactive intestinal peptide. The localization of CGRP-containing nerve fibres suggests that CGRP is involved in the regulation of secretion and blood flow of salivary glands. CGRP may interact positively with acetylcholine and certain nonclassical transmitters, and it may be involved (together with other neuropeptides) in the atropine-resistant parasympathetic secretion occurring in the glands under study.

Amylases↗
PubMed1988

Characterization of alkaline phosphatase from buccal mucosa in young rats.

Alkaline phosphatase (APase) is a plasma membrane-integrated protein with unknown function and is found in many different tissues of the body. It is normally not present in squamous epithelium. Nevertheless, it has been demonstrated in developing rat oral epithelium, where it exists together with several different phosphatases. In this study APase was solubilized from rat buccal mucosa and partially purified by gel chromatography followed by ion-exchange chromatography. Three isoenzymes with similar kinetic characteristics but different sensitivities to heat inactivation were obtained. All three had a pH optimum of 10.2 and a Michaelis-Menten constant of 0.3 mM. Combined chromatographic/electrophoretic and histochemical tissue section analysis of APase isoenzymes indicated that the buccal mucosa of young rats contains three APase isoenzymes, two of which are of epithelial origin and the third of endothelial origin.

Alkaline Phosphatase↗
PubMed1987

Effects of bone wax on rabbit cranial bone lesions.

The present study was designed to elucidate the reactions of cranial membranous bone to bone wax. In ten young rabbits, twenty parietal bone defects were created by drilling, the edges of which were partly extended using rongeur forceps to enable investigation of eventual thermal effects. Half of the marginal bone surrounding the lesions was covered by bone wax, the remainder serving as control. The animals were sacrificed 1 and 7 weeks after surgery, and block specimens prepared for light microscopy. Merely slight tissue reactions to the bone wax were discerned. Bony regeneration occurred mainly from the dura mater and the pericranium, but also from the bony rim. Reskeletalization was markedly impaired by the presence of bone wax. Heat generated by drilling caused reduced bone formation despite constant irrigation peroperatively. Clinical consequences are discussed.

Animals↗
PubMed1986

Zinc and alkaline phosphatase in developing rat oral mucosa.

Alkaline phosphatases (AlkPase) of many different tissues and species have been shown to be zinc metalloenzymes. Specific regions of rat oral mucosa have a high activity of AlkPase. Combined autoradiography and enzyme histochemistry showed that they also retained injected radioactive zinc (65Zn). The AlkPase activity was inactivated by EDTA and reactivated with zinc. However, it could not be verified by polyacrylamide gel electrophoresis combined with radioactivity measurements and enzyme analysis that the 65Zn uptake of oral mucosa was incorporated in the AlkPase molecule.

Alkaline Phosphatase↗
PubMed1984

The odontogenic keratocyst: a benign cystic tumor?

Three hundred nineteen odontogenic keratocysts from 255 patients (167 males and 88 females, a 2:1 ratio) were histologically and clinically examined. The cysts sometimes occurred as multiple or recurrent lesions or in association with Gorlin's syndrome. The rate of recurrence for the total population was 27%. The 116 patients who were tentatively diagnosed as having keratocyst prior to surgery had a recurrence rate of 26%. There was no direct correlation between a large number of different histopathologic parameters and the propensity of a lesion to recur. Based on these data, a theory for the growth mechanism of these lesions is presented, and it is that the odontogenic keratocyst should be regarded as a benign cystic neoplasm and treated accordingly.

Adolescent↗
PubMed1984

Lactate dehydrogenase in developing rat oral epithelium.

Freeze-dried sagittal, whole-body sections of 10-day-old rats were incubated for lactic dehydrogenase (LDH) using different media in the presence of the inhibitors urea and fluoropyruvate. Phenazine methosulfate (PMS) and menadione, which are regularly used in current histochemical media and are believed to promote the demonstration of LDH activity, were also added and shown to be insufficient for the demonstration of total LDH activity, and PMS even seemed to have an inhibitory effect on LDH activity in oral epithelium. However, cumulated data from the different incubations show that the oral epithelium of developing rats may contain two different types of LDH, one in the basal cells with possibly aerobic characteristics, and another in the spinosum/granulosum cells with anaerobic characteristics.

Animals↗
PubMed1984

Acid, neutral, and alkaline phosphatases in developing rat oral mucosa.

Developing rat oral mucosa contains high activities of acid (AcidPase), neutral (adenosine monophosphatase AMPase), and alkaline (AlkPase) phosphatases. This study is concerned with a detailed analysis of the distribution of these enzymes in freeze-dried sections of oral mucosa. The sections were incubated for AcidPase. AMPase, and AlkPase in the presence of certain inhibiting agents. Four AcidPases, three AMPases, and two AlkPases were identified in the oral mucosa. Six of them were found in the epithelium and three in the connective tissue. Three of the epithelial phosphatases were unique in the sense that they were found only in junction mucosa epithelium. The function of these enzymes may be related to the maintenance of the epithelial cell attachment in an area subjected to stretching, possibly by affecting the periphery of the cells.

Acid Phosphatase↗
PubMed1984

Lactate dehydrogenase isozymes in developing rat oral mucosa. A comparative study of LDH biochemistry and histochemistry.

Histochemical lactic acid dehydrogenase (LDH) staining methods seem unable to demonstrate the total LDH activity in tissue sections. An analysis was made of LDH tissue staining methods applied on LDH zymograms. The menadione-mediated LDH staining of tissue sections can not possibly reflect true LDH activity. The addition of cyanide also slightly inhibited LDH activity. The cyanide inhibition was confirmed via LDH assay and found to be competitive in character. It is concluded that cyanide and menadione should be replaced by agents suitable from both a histochemical and a biochemical point of view. Based on the findings of this study the presence of LDH in oral epithelium was analyzed. Evidently LDH of the oral epithelium is basically anaerobic in character and located primarily in spinosum/granulosum layers and only sparsely in the basal layer.

Animals↗
PubMed1980

Cardiovascular complications to treatment of prostate cancer with estramustine phosphate (Estracyt) or conventional estrogen. A follow-up of 212 randomized patients.

Two hundred and twelve patients treated for prostatic cancer grade I or II were investigated for cardiovascular complications. The patients were part of a multicentre study in the Stockholm area and had been randomized to treatment with either estramustine phosphate (Estracyt) or polyestradiol phosphate and ethinyl estradiol. Cardiovascular complications categorized as impaired arterial circulation including ischemic heart disease, venous thromboembolism, cardiac incompensation and cerebral depression were found to be equally frequent following the two different forms of treatment. Among the patients getting cardiovascular complications, these occurred within two months after the start of treatment in 50% and within one year in 85% of them. There was a statistically significant correlation between the incidence of cardiovascular complications and a history of previous cardiovascular disease. This criterion was however in retrospect found to predict cardiovascular complications in only 67 of the 126 patients getting one or several of these complications.

Aged↗
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↗
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

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↗
PubMed1976

Congenital left ventricular apical aneurysm.

An aneurysm of the left ventricular apex was accidently discovered on chest X-ray in an otherwise healthy 3 1/2-year-old-girl. Pre-operatively performed heart catheterization and ciné-angiography were followed by successful surgical removal of the aneurysm. Microscopic examination showed that the three layers of the myocardium were present, although it was degenerated by fibrosis. This case belongs to the fibrous type of aneurysm, which is the most rare type, not associated with other developmental defects, usually asymptomatic until there is rupture and sudden death, or the condition is accidentally discovered on chest X-ray and treated surgically.

Child, Preschool↗