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Biomedical subjects

H S Koppang

Publications and source records attributed to H S Koppang.

At least 37 records · Page 2Linked to original sources
PubMed1988

Autoradiographic investigation of effects of high-dose colchicine on dentinogenesis in rat incisors.

Twelve female Wistar rats received 1.5 mg/kg of colchicine (CLC) intravenously. Control animals were similarly injected with isotonic saline solution. The animals were killed 5 h, 24 h, 3 days and 7 days after injection. Ninety minutes prior to sacrifice, all animals received an intraperitoneal injection of 3H-proline. Autoradiograms of maxillary incisors showed that CLC increased the retention of the labeled precursor in the odontoblasts. It was also shown that the odontoblasts in the different sectors of the rat incisor present different sensitivities to the CLC action.

Animals↗
PubMed1987

Human papillomavirus type 13 and focal epithelial hyperplasia of the oral mucosa: DNA hybridization on paraffin-embedded specimens.

16 cases of focal epithelial hyperplasia (Heck's disease) were studied for the presence of human papillomavirus DNA by means of nucleic acid hybridization. Hybridization was carried out in situ with biotin-labelled probes of HPV 1, 6, 11, 13, 16, and 18 DNA under stringent and non-stringent conditions. Under non-stringent conditions, 6 of 16 cases (38%) hybridized to a mixture of HPV 1, 6, 11, 16, and 18 DNA. When these probes were applied under stringent conditions, only one case could be shown to be weakly positive for HPV 6/11 DNA. Further stringent hybridizations, which were conducted with a HPV 13 probe on 12 of our 16 cases, revealed a positive result in 9 of 12 cases (75%). The results of our study strongly substantiate the concept that HPV 13 or a closely related HPV type is associated with lesions morphologically presenting as focal epithelial hyperplasia.

Adult↗
PubMed1987

Identification of cellulose fibers in oral biopsies.

Oral biopsies comprising five periapical cysts, three cases of exuberant granulation tissue in extraction sockets and one case of a mandibular radiopaque structure, all displaying material consistent with cellulose fibers on routine histologic examination, were subjected to histochemical, polarization, fluorescence and scanning electron microscopical, energy dispersive X-ray and chemical investigations. Routine screening of periapical lesions with polarization microscopy and identification of possible cellulose fibers with Calcofluor White is advocated. Further, attention is drawn to endodontic paper point material as an etiologic factor in postendodontic periapical inflammatory processes.

Adolescent↗
PubMed1986

Multiple endocrine neoplasia, type III.

Multiple oral plexiform neuromas in a 14-year-old white girl prompting screening of the patient with respect to the multiple endocrine neoplasia (MEN) type-III syndrome, verified the existence of a thyroid medullary carcinoma and the diagnosis MEN-type III. Total thyroidectomy was performed, but extensive tumour infiltration prevented radical tumour excision. The condition being relatively infrequent, the important life-saving role of dental practitioners and oral surgeons in its recognition and early diagnosis is emphasized.

Adolescent↗
PubMed1986

Local immunoreactivity and human papillomavirus (HPV) in oral precancer and cancer lesions.

A retrospective longitudinal study was performed on 20 patients with oral leukoplakia, 10 of which developed an oral squamous cell carcinoma, to assess whether any alterations in the local immunologic reactivity could be found of value in predicting the subsequent behavior of the lesions. During the major period of follow-up, the relative frequency of in situ IgA-producing plasma cells was significantly higher in biopsies from patients subsequently developing cancer than in patients showing no cancer development. Preceding the malignant transformation by 12 to 15 months, however, a remarkable shift from IgA to IgG plasma cell predominance was noticed in the biopsies of the cancer series, not detectable in the non-cancer group. HPV group specific capsid antigens were found in seven cases of the cancer series and in six of the non-cancer group. The possible diagnostic implications of these results are discussed.

Adult↗
PubMed1984

Dental features in congenital persistent renal tubular acidosis of proximal type.

The dental features in a hitherto unknown type of renal tubular acidosis (capillary blood pH 7.07-7.15) of proximal type are reported. The patient presented agenesis of three second premolars, delayed development and eruption of permanent teeth, delayed shedding of the primary dentition and severe enamel hypoplasia of the permanent teeth. Apart from exceptionally thin enamel, histologic, fluorescent and polarization microscopic and microradiographic investigation of three primary teeth did not reveal unusual findings. The changes are most probably due to a generalized, acidosis-induced defect in several highly differentiated ectodermal tissues.

Acidosis, Renal Tubular↗
PubMed1981

Colchicine's effects on rat incisor odontoblasts and dentinogenesis.

Colchicine (CLC) in doses of 0.5 and 1.5 mg/kg was administered to 40 female Wistar rats in two equal groups. The animals were sacrificed after 5 h, 24 h, 3 d and 7 d, and the effects of CLC on pulp, odontoblasts and dentin in the continuously growing incisors were studied. With the lowest dose a few arrested mitoses were observed in the germinative part of the pulp after 5 and 24 h. With the highest dose an increasing number of mitoses were observed in the germinative part of the pulp after 5 and 24 h. More incisally the odontoblasts were pale, swollen and granulated after 5 h, and necrotic and disintegrated after 24 h. After 3 and 7 d dentinal derangements, consisting of moderately and severely irregular dentin, osteodentin and a niche-like defect in the labial dentin, were seen. Labially one or two incremental lines traversed the dentin from the apical to the incisal part of the incisors.

Animals↗
PubMed1981

Effect of cyclophosphamide on dentinogenesis in the rat incisor: fluorescence microscopic and microradiographic investigations.

Previously described dentin reactions to cyclophosphamide (CPhA) were studied by means of fluorescent labeling and microradiography. Ten adult rats received 20 mg/kg calcein i.p. on days 0, 4, 7, 10, and 40 mg/kg CPhA 30 min after the first calcein injection. Two animals served as controls. The observation time was 14 d. Fluorescence microscopy and microradiography of the maxillary incisors revealed 1)niche-like defects in dentin starting in mineralize 1-4 d after the CPhA administration labially, while lingually the niches developed later and were completed earlier, 2)localized reduced and increased growth lingually, 3)continuous but reduced apposition of a hypomineralized dentin in the niches, and 4)niche osteodentin produced by pulp cells.

Animals↗
PubMed1980

Long-term effects of colchicine on dentinogenesis in rat incisors.

Colchicine in doses of 0.5, 1.0 and 1.5 mg/kg was administered to 15 rats divided in three experimental groups. Histomorphologic investigation of the maxillary incisors after 2 weeks revealed; 1) alterations in the odontoblasts mainly related to size, shape, polarity and staining properties, and 2) presence of irregular dentin separated from normal dentin by one or two incremental lines. The dentinal irregularities were dose-dependent and consisted of twisting of the dentinal tubules, globular formations and cellular inclusions in addition to niche-like defects.

Animals↗
PubMed1980

Autoradiographic investigation of proliferative responses in rat incisor pulp after vincristine administration.

-0.7 mg/kg VCR was given to nine rats in three experimental groups. Twenty-three hours after VCR injection the animals were injected with 3H-thymidine. The animals were sacrificed 24, 48 and 72 h after the VCR injection, and by comparison with nine control animals similarly injected with sodium chloride solution and nucleotide, it was shown that VCR causes a delayed migration of pulp cells from the proliferative pool and a small but distinct inhibition of the incisal growth of the incisors. The growth inhibition corresponded to the normal growth over a 24-h period in non-VCR-injected animals.

Animals↗
PubMed1980

Autoradiographic investigation of dentin production in rat incisors after vincristine administration.

0.7 mg/kg VCR was administered intravenously to nine rats in three experimental groups. One hour after VCR injection the animals were injected with 3H-proline. The animals were sacrificed 1.5, 5 and 24 h after the VCR administration, and by comparison with nine control animals similarly injected with sodium chloride solution and 3H-proline, it was shown that VCR causes an early, intracellular retention of labeled proline in the odontoblasts, an abnormal intracellular distribution of labeled material and a generally decreased secretion of dentinal matrix from the odontoblasts in the maxillary incisors. The severity of the effects were shown to vary in different parts of the incisors.

Animals↗
PubMed1979

Fibro-osseous lesions of the cranio-facial bones.

A brief review of cranio-facial fibro-osseous lesions is given and 15 cases of fibrous dysplasia and ossifying fibroma are presented with clinical, radiological and histomorphological findings. After histological verification of the fibro-osseous nature of the process, 5 lesions were diagnosed on an radiological basis as fibrous dysplasia exhibiting diffuse (blending) margins, while the diagnosis of ossifying fibroma was given to 10 radiologically sharply-demarcated lesions. Both groups of lesions presented the same histomorphological features, although to a varying degree. Spheroidal calcifications, however, were identified in ossifying fibroma only, but not in all of these. Thus, the differential diagnosis of fibrous dysplasia versus ossifying fibroma rests on a radiological criterion after the histopathologist has verified the fibro-osseous nature of a lesion. The observation times varied from 1 1/2 to 34 years. Two cases of fibrous dysplasia and 3 cases of ossifying fibroma recurred. In one case of fibrous dysplasia an osteosarcoma developed 33 years after irradiation. Pain was a common symptom in the present material.

Adolescent↗