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Biomedical subjects

G Bang

Publications and source records attributed to G Bang.

At least 19 recordsLinked to original sources
PubMed1992

Effect of local hemostatics on bone induction in rats: a comparative study of bone wax, fibrin-collagen paste, and bioerodible polyorthoester with and without gentamicin.

Local hemostatics for osseous tissue should preferably be absorbable and biocompatible and should not inhibit osteogenesis. The tissue response and effect on demineralized bone-induced heterotopic osteogenesis in the abdominal muscle of 120 male Wistar rats by different local hemostatics were evaluated by light microscopy and 85Sr uptake analyses. Non-absorbable bone wax of 88% beeswax and absorbable bovine fibrin-collagen paste both significantly inhibited osteoinduction, whereas a bioerodible polyorthoester drug delivery system with or without 4% gentamicin did not. Bone wax was not absorbed and induced a chronic foreign body reaction. Fibrin-collagen paste induced less inflammation with numerous monocytes and macrophages with engulfed material. Bioerodible polyorthoester caused a very moderate tissue reaction and was mostly resorbed at week 4.

Absorption↗
PubMed1992

The "Scandinavian Star" ferry disaster 1990--a challenge to forensic odontology.

With 158 victims, the fire on board the "Scandinavian Star" was one of the world's worst ferry disasters. A team of identification experts, including dentists, were employed to secure evidence for identification and to remove the victims from the ferry. Four parallel teams, each with 2 dentists, examined and autopsied the victims at the Institute of Forensic Medicine, University of Oslo. Using the INTERPOL Disaster Victim Identification forms and aided by computers, all victims were identified within 17 days. Dental identity could be established in 107 cases (68%).

Adolescent↗
PubMed1992

Bone induction by composites of bioresorbable carriers and demineralized bone in rats: a comparative study of fibrin-collagen paste, fibrin sealant, and polyorthoester with gentamicin.

Host tissue response and heterotopic osteoinduction by composites of demineralized bone matrix and three different substances used as bioresorbable carriers implanted in the abdominal muscles were evaluated by strontium 85 uptake and histology 4 weeks postoperatively in 60 male Wistar rats. Both fibrin-collagen paste and fibrin sealant inhibited bone induction and produced a chronic inflammation; part of the fibrin-collagen paste was still present at 4 weeks. Polyorthoester with gentamicin was almost completely absorbed, induced minimal tissue reaction, and did not inhibit osteoinduction.

Absorption↗
PubMed1992

Chemical, physical, and histologic studies on four commercial apatites used for alveolar ridge augmentation.

The purpose of this study was to evaluate four commercial apatite products. Subperiosteal alveolar ridge augmentation was performed on the maxilla of rats by implantation of granules of two dense products and of two porous products, and the tissue response was compared with the material characteristics obtained by chemical analysis and infrared spectrometry. None of the apatites caused osteoinduction or osteoconduction; fibrous encapsulation with multinuclear giant cells was observed around all four types. One of the apatites was fluorapatite and not hydroxylapatite, as claimed by the manufacturer. The tissue response to this implant material was dominated by multinuclear giant cells.

Alveolar Process↗
PubMed1992

Alveolar ridge augmentation by osteoinductive materials in goats.

The purpose of the present study was to determine whether alveolar ridge augmentation could be induced in goats. In 12 male goats allogenic, demineralized, and lyophilized dentin or bone was implanted subperiosteally on the buccal sides of the natural edentulous regions of the alveolar process of the mandible. Light microscopic evaluation revealed fibrous encapsulation, a few multinuclear giant cells, little inflammatory reaction, and no osteoinduction. It was concluded that no osteoinduction took place in goats.

Alveolar Ridge Augmentation↗
PubMed1992

Comparison of histomorphometry and 85Sr uptake in induced heterotopic bone in rats.

Heterotopic bone formation in the abdominal muscle of 45 male 8-week-old Wistar rats induced by implantation of 5, 10, or 15 mg demineralized bone (DBM) powder was evaluated at 4 weeks by 85Sr uptake of the implants and area histomorphometry of the induced bone. Two indices of 85Sr uptake were calculated: the osteogenic index [(counts/min/mg implant)/(counts/min/mg os ilium)] and an index that we have called the osteoquantum index in which the weight of the implant is disregarded [(counts/min implant)/(counts/min/mg os ilium)]. The osteoquantum index showed a linear relationship to the area of the induced bone with a correlation coefficient (r) of 0.90. Only weak linear relationships were found between the osteogenic index and the area of the bone (r = 0.32) and between the osteogenic index and the osteoquantum index (r = 0.33). The osteoquantum index and the area of the induced bone both increased with increasing mass of implanted DBM, whereas the osteogenic index did not change.

Analysis of Variance↗
PubMed1992

Regeneration of calvarial defects by a composite of bioerodible polyorthoester and demineralized bone in rats.

A study was performed to evaluate regeneration of defects in rat calvaria either unfilled or filled with a bioerodible polyorthoester only, demineralized bone only, or a composite of both. At 4 weeks, histological and radiographic studies showed that defects filled with a composite of bioerodible polyorthoester and demineralized bone or demineralized bone alone were bridged by bone. Unfilled defects or defects filled with polyorthoester only did not heal. The polyorthoester caused slight inflammation that subsided by 3 weeks, and only traces of the filler could be detected at 4 weeks. The polyorthoester provided local hemostasis when used either alone or in composites with demineralized bone. The composite implant was moldable, easily contoured, and technically easier to use than demineralized bone alone.

Animals↗
PubMed1992

Inhibition of heterotopic osteogenesis in rats by a new bioerodible system for local delivery of indomethacin.

A study was done to evaluate the effect of a system for the local delivery of indomethacin on demineralized bone-induced formation of heterotopic bone in the abdominal muscles of rats. Two separate investigations were conducted on a total of forty-eight Wistar rats. In both series, two types of implants were used: polyorthoester and demineralized bone (Group A, the control group) and polyorthoester with 5 per cent indomethacin and demineralized bone (Group B, the experimental group). In the first series, host-tissue responses and osteoinduction were evaluated histologically at two, three, and four weeks after the implantation. In the second series, the formation of bone was quantified on the basis of uptake of 85Sr at four weeks after the implantation. The polyorthoester system for the local delivery of indomethacin significantly inhibited demineralized bone-induced heterotopic formation of bone, as demonstrated by light microscopy and by uptake of 85Sr. The polyorthoester, with or without the drug, caused little tissue reaction and was resorbed almost completely at four weeks.

Abdominal Muscles↗
PubMed1992

The effect of a composite of polyorthoester and demineralized bone on the healing of large segmental defects of the radius in rats.

The effect of a composite of demineralized bone mixed with polyorthoester on the healing of large segmental defects in the rat radius was studied. Sixty male Wistar rats were divided into four groups, A through D, and an osteoperiosteal diaphyseal defect of 50 per cent of the length of the bone was made in the right radius of each rat. In Group A, the defect was filled with polyorthoester and demineralized bone; in Group B, demineralized bone; and in Group C, polyorthoester. No material was implanted in the defects in the Group-D rats. The rats were killed fifty days postoperatively. The formation of bone in the defects was quantified with computer-assisted measurements of the area on radiographs. The host-tissue response was evaluated with light microscopy. Defects that had been filled with the composite of polyorthoester and demineralized bone or with demineralized bone alone showed regeneration of bone corresponding to 93.6 and 77.6 per cent of the area of the defect, respectively. Defects that had no implant or that had been filled with polyorthoester alone showed significantly less formation of bone. No inflammation was seen with light microscopy, and only traces of the polyorthoester could be detected in the defects that had been filled with the composite or with polyorthoester alone.

Animals↗
PubMed1991

Geographic stomatitis: report of 6 cases.

The macro- and microscopic appearance and results of microbiologic and immunohistochemical investigations in six patients with geographic stomatitis are described. On the background of similarities in both the clinical, histologic and immunohistochemical findings it is felt that psoriasis and stomatitis geographica are related lesions.

Adult↗
PubMed1991

Alveolar ridge augmentation in rats by combined hydroxylapatite and osteoinductive material.

The purpose of this study was to examine if increased bony ingrowth developed when hydroxylapatite was implanted together with an osteoinductive substrate. Dense hydroxylapatite granules (HA) (Calcitite, Calcitek, San Diego, CA, USA) were mixed with equal volumes of allogenic, demineralized, lyophilized dentin or bone and implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal muscles in rats. Light microscopic evaluation revealed that HA was surrounded by fibrous connective tissue containing foreign body giant cells and it had neither an osteoinductive nor an osteoconductive effect. The newly formed bone induced from the implanted allogenic, demineralized, lyophilized dentin or bone was never found in close contact with the HA and did not incorporate the implant.

Abdominal Muscles↗
PubMed1991

Alveolar ridge augmentation in rats by Bio-Oss.

The purpose of the study was to examine if Bio-Oss initiated osteoinduction or osteoconduction when implanted into rats. Sintered and unsintered granules of the anorganic bovine bone Bio-Oss was implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal muscles of rats. Light microscopic evaluation revealed no osteoinduction or osteoconduction in connection with sintered or unsintered Bio-Oss. A foreign body reaction was observed around both forms.

Abdominal Muscles↗
PubMed1991

Sarcoidosis of the uterus.

Sarcoidosis rarely involves the female genital tract. A report is presented of 2 cases of sarcoidosis of the uterus. In the first, the diagnosis was made by biopsy of the portio vaginalis uteri which was amputated during the Manchester operation for genital prolapse. In the second case the diagnosis was made by endometrial curettage for postmenopausal vaginal bleeding. Neither of the women exhibited signs of generalized sarcoidosis.

Aged↗
PubMed1990

[Localized amyloidosis of the lower respiratory tract].

Primary amyloidosis localised to the lungs can simulate different types of lung diseases such as tuberculosis, carcinoma and repeated infections in the lower respiratory tract. The possibilities of treatment are limited. The prognosis is usually good, except when there is diffuse pulmonary involvement. Such patients can develop progressive respiratory failure The mechanism of amyloidogenesis is unclear. At the cellular level the macrophage may play a central role.

Amyloidosis↗
PubMed1990

Intramuscular hemangioma in the oral region: report of three cases.

The occurrence of intramuscular hemangioma in an intraoral or perioral localization is rare, and a thorough knowledge of these tumors is necessary for adequate diagnosis and treatment. Three cases are presented with discussion, and their histopathology and differential diagnosis are discussed. An adequate primary excision is necessary to avoid recurrence.

Adolescent↗
PubMed1990

Alveolar ridge augmentation by osteoinduction in rats.

The purpose of this study was to evaluate bone substitutes for alveolar ridge augmentation by osteoinduction. Allogenic, demineralized, and lyophilized dentin and bone was tested for osteoinductive properties in order to establish an experimental model for further studies. Implantations were performed subperiosteally on the premaxilla and heterotopically in the abdominal muscles of rats. Light microscopic evaluations revealed that all allogenic, demineralized, and lyophilized dentin and bone implants induced new bone formation. No inflammatory or foreign body reactions were observed.

Abdominal Muscles↗
PubMed1989

Clear cell odontogenic carcinoma: report of three cases with pulmonary and lymph node metastases.

Three cases of a newly described rare odontogenic tumor are reported. One patient died with pulmonary metastases, one had an associated odontogenic cyst and one exhibited regional lymph node metastasis. The cases lend support to the odontogenic origin and metastatic capability of the clear cell odontogenic tumor. The authors recommend aggressive therapy and believe that the tumor should be considered a clear cell odontogenic carcinoma.

Aged↗