Search PubMed⌕ Search

Biomedical subjects

J M Hirsch

Publications and source records attributed to J M Hirsch.

At least 55 records · Page 3Linked to original sources
PubMed1988

Autogenous free tooth transplantation in man by a 2-stage operation technique. A longitudinal intra-individual radiographic assessment.

Insufficient nutrition to the root surface of autotransplanted mature human teeth after transplantation could be an explanation for the high rates of complications such as root resorption and loss of the tooth transplant. Insufficient nutrition is suggested as being due to the distance between the recipient site tissue and the root surface, and the presence of a blood-clot between the tissues. Improved nutrition could be achieved by transplanting into contact with the vascularised connective tissue of a healing wound. To test this hypothesis, a series of human teeth with fully developed roots were autotransplanted to recipient sites prepared and left to heal for 14 days before transplantation. This study is a follow-up of 57 transplants with a minimum observation time of 1 year. Periodic radiographic examinations of the teeth were performed up to 5 years after transplantation. The results presented, showed a lower incidence of root resorption and extractions than previously reported for teeth with fully developed roots.

Adolescent↗
PubMed1986

The reversibility of the snuff-induced lesion: an experimental study in the rat.

Snuff lesions were induced in 30 rats. Ten of the snuff-exposed rats were killed immediately after 13 months snuff exposure, as were the 10 control animals. Ten rats were killed 1 month and 10 rats 4 months after the snuff administration had ceased. The rats exposed to snuff for 13 months exhibited hyperplastic, hyperorthokeratotic epithelium with focal mild atypia, focal ulcerations and marked subepithelial fibrosis. These changes were markedly reduced or absent in rats exposed to snuff and killed after a snuff-free interval of 1 or 4 months. Similar differences between the test-groups were seen in the epithelium lining the gingival sulcus of the lower incisors. This area seems to be more sensitive to chemical exposure than the oral mucosa proper as more severe microscopical changes were seen here. Snuff exposure results in the development of a hyperplastic, reactive, reversible lesion of the oral mucosa, suggesting that snuff predominantly has promoting activity when administered for a relatively short interval of time.

Animals↗
PubMed1984

Effect of snuff and herpes simplex virus-1 on rat oral mucosa: possible associations with the development of squamous cell carcinoma.

The purpose of this investigation was to study the effect of snuff and experimentally induced herpes simplex virus type 1 (HSV-1) infection in Sprague-Dawley rats. It was demonstrated that it was possible to obtain 100% development of acute HSV-1 infection in the rat oral mucosa, but only 10% of latent reactive infection of the trigeminal ganglia. The rats were, therefore, acutely infected monthly with virus to simulate recurrence of latent infection. Virus was applied topically to the mucous membrane twice with an interval of one month. Snuff was administered between the virus applications and afterwards to half the virus-exposed animals. Sham-infected rats were given snuff during the same period (18 months). A fourth group of rats were left untreated. A complete post-mortem examination was performed. Two rats exposed to snuff and HSV-1 in combination developed squamous cell carcinoma of the oral cavity. It was also found that rats exposed to snuff alone or in combination with HSV-1 had a higher incidence of tumours or tumour-like conditions than control rats exposed to HSV-1 only. The incidence of malignant tumours was significantly higher in rats exposed to snuff or HSV-1 and snuff in combination than in control animals (p less than 0.05). The results of the study indicate that HSV-1 in combination with snuff exposure may be associated with the development of squamous cell carcinomas of the oral cavity.

Acute Disease↗
PubMed1984

Effect of long-term application of snuff and herpes simplex virus 1 on rat oral mucosa. Possible association with development of oral cancer.

In an animal model, the life-long effects of snuff administration were assessed alone and in combination with infection with herpes simplex virus (HSV-1). It was shown that exposure to standard and alkaline snuff and to HSV-1/snuff induced mild to severe hyperplasia, hyperorthokeratosis, varying degrees of vacuolization and acanthosis in the squamous epithelium, as well as atrophic and ulcerated lesions. Ulcerations and mild dysplasia of the squamous epithelium were seen most frequently in HSV-1/snuff-exposed rats, with moderate dysplasia in the crevicular epithelium. Rats exposed to snuff or to HSV-1 and snuff had a higher incidence of tumours or tumour-like conditions than control rats. Squamous-cell carcinoma of the oral cavity was found exclusively in rats exposed to snuff or to the combination of HSV-1 and snuff. Papillary squamous hyperplasia of the forestomach was found only in rats exposed to snuff or to HSV-1 and snuff in combination. The incidence of malignant tumours was significantly higher (p less than 0.05) in the group of rats exposed to snuff and HSV-1/snuff than in control animals.

Animals↗
PubMed1984

Inhibition of herpes simplex virus replication by tobacco extracts.

Herpes simplex virus type 1 (HSV-1) has been associated with the genesis of leukoplakias, epithelial atypia, and oral cancer. Tobacco habits, such as snuff dipping, are also definitely correlated with this type of lesion. The normal cytolytic HSV-1 infection can, after in vitro inactivation, transform cells. Extracts of snuff were prepared and assayed for their ability to inhibit HSV-1 replication. Plaque formation assays of HSV-1 in the presence of snuff extract showed that a reduced number of plaques was formed. Different batches of one brand of snuff were tested for inhibition of herpes simplex virus (HSV) production. More than 99% inhibition of 24-hr HSV production was obtained with undiluted batches. The 1:5 dilutions of snuff had an inhibitory effect of 85% and 1:25 dilutions, 39%. In agreement, the attachment of the virus to the host cell and penetration of the virus to the cell nuclei were found to be inhibited as was the synthesis of viral DNA. Nicotine had an inhibitory effect, while aromatic additions to snuff were found to have no major inhibitory effect on HSV replication. Snuff extracts were prepared from different brands of snuff reported to contain high and low quantities of tobacco-specific N-nitrosamines. Brands with reported high levels of tobacco-specific N-nitrosamines had significantly greater ability to inhibit HSV replication. In conclusion, this study has shown that extracts of snuff have inhibitory effects on the production of cytolytic HSV-1 infections. A chronic snuff dipper keeps tobacco in the mouth for the major part of the day. Thus, virus shed in the oral cavity in connection with a reactivated latent HSV-1 infection has great possibilities of being affected by snuff or derivatives of snuff. It is suggested that an interaction between tobacco products and HSV-1 might be involved in the development of dysplastic lesions in the oral cavity.

Animals↗
PubMed1983

Effect of long-term application of snuff on the oral mucosa: an experimental study in the rat.

The long-term effect of snuff exposure was studied in Sprague-Dawley rats using a surgically-created test canal in the lower lip to retain snuff. The rats received standard snuff (n = 42) and highly alkaline snuff (n = 10) for 9-22 months, whereupon they were killed. Untreated rats with identical test canals (n = 15) served as controls. A complete post-mortem examination was performed. One rat exposed to standard snuff for 9 months developed a squamous cell carcinoma of the oral cavity. However, exposure to standard snuff usually resulted in a mild to moderate hyperplasia of the epithelium, hyperorthokeratosis and acanthosis. Rats exposed to snuff for 18-22 months showed vacuolated cells penetrating deeper into the epithelium with hyperplastic and atrophic lesions. In a few rats, severe dysplastic changes developed in the crevicular epithelium. Rats exposed to alkaline snuff differed little from the first group except that there was focally atrophic and ulcerated epithelium and less fibrosis. Pathological findings outside the oral cavity were rare. Squamous cell hyperplasia of the forestomach was found in rats exposed to snuff for 18-22 months, possibly caused by ingested snuff. In conclusion, this study has shown that exposure of rats to snuff for 10-16 hours per day 5 days a week for most of their life-span resulted in lesions mainly restricted to the epithelium and the underlying connective tissue of the surgically created test canal.

Acantholysis↗
PubMed1982

A clinical, histomorphological and histochemical study on snuff-induced lesions of varying severity.

The oral lesions in 50 habitual snuff-dippers were graded on a four-point scale. The patients' tobacco and drinking habits were studied by means of a questionnaire. From each patient a biopsy was taken for histomorphological and histochemical analysis. A correlation between snuff habits and the clinical degrees was found, as well as between the snuff habits and certain superficial and deeply located cell changes. The incidence of keratinized lesions, sialadenitis and slight dysplasia (based on subjective evaluation under a light microscope) was higher than previously reported. Presence of dysplastic changes could not be predicted by means of the parameters which characterise the snuff habit or from the clinical grade. The histomorphological and histochemical results were interpreted as showing that the mucosa react to snuff inducing hyperplasia in the basal cell layers. In the surface layer indications of lethal damage were found. The overall stromal reaction to snuff was weak. However, the salivary glands and excretory ducts exhibited degenerative changes which were found to be more severe than the pathological changes in the surface epithelium.

Adult↗
PubMed1981

Snuff-induced lesions of the oral mucosa - an experimental model in the rat.

An experimental model in the white rat has been developed in order to study the influence of snuff on oral mucosa. A test canal in the lower lip, with one orifice buccally to the incisors and one on the lip side, was created by surgical means. The connection between the canal and the oral cavity was made to ensure the presence of saliva in the canal so that physiological conditions resembling those of the oral cavity were obtained. The canal was filled with snuff morning and night 5 days a week. The mean value for the maximal retention time of the snuff was 6 h. The animals tolerated the dose and time of exposure without signs of severe toxic symptoms. Histological examination of the canals after 9 months of exposure to snuff showed a mildly to moderately hyperplastic epithelium with hyperorthokeratosis. Locally deep proliferations of epithelium with acanthotic rete pegs could be seen. In the stratum basale hyperplasia with disturbed polarity and hyperchromatic nuclei and single mitosis were noted.

Animals↗
PubMed1979

Periapical surgery.

A retrospective study of 572 teeth treated with periapical surgery was undertaken in order to evaluate the influence of preoperative, operative and postoperative factors in the healing process as well as the operation method used. It was also the aim to assess whether the histophatological diagnosis of biopsies taken at the operation could be correlated to healing. Statistical analyses by the AID method and conventional cross-classification methods were performed. Factors of importance were found to be the extent of the destrucion, the operation method used, the bone surrounding the destruction, the quality of the orthograde root filling, the age of the patient, and the marginal bone buccally. The operation method was of importance in large destructions where root fillings were considered as not having properly sealed the canals, and when treating inflamed cysts. The histopathological diagnosis could not be ascribed any definite prognostic value.

Adolescent↗
PubMedDate not supplied

Maxillary sinus augmentation using mandibular bone grafts and simultaneous installation of implants. A surgical technique.

This paper presents a specific technique for maxillary sinus augmentation and simultaneous placement of implants in partially edentulous patients. In such patients, there is from time to time insufficient interarch distance for any type of onlay grafting. Health, non-smoking patients without previous or present sinus pathology, where the radiological and clinical examination revealed insufficient height and/or width of the remaining alveolar process in the posterior maxillary region, were selected. They were operated on using a mandibular bone graft obtained from the symphyseal region between the mental foramina and placed in the maxillary sinus. The recipient site was prepared by cutting in a rectangular shape the lateral sinus wall into the sinus lining. The bone wall was then separated towards the lateral nasal wall by rotating the inferior portion of the cut sinus wall medially. In the space thus created, the bone graft was placed. Fixtures were installed at the same session. The method described has proved to be uncomplicated to perform under local anesthesia and no major disadvantages for the patient or pre- or postoperative complications have so far been observed.

Alveolar Bone Loss↗
PubMedDate not supplied

Human papilloma viruses in oral lesions.

Oral mucosa biopsies from 53 patients with different oral diseases, and from 12 healthy control patients, were examined by the PCR-technique using the L1 consensus primers and type-specific primers for HPV 6/11, 16 and 18. Three out of 24 (12.5%) oral cancer biopsies were HPV positive, 1 for HPV 18, 1 for HPV 16 and 6/11 and 1 for none of the specific primers. Six out of 22 (27.3%) lichen planus were HPV positive, 5 for HPV 18 and 1 for none of the specific primers. Seven leukoplakias were included in the study and 2 (29.6%) were positive for both HPV 16 and 6/11. None of the 12 control patients was HPV positive. No statistical difference between the use of tobacco and alcohol and HPV prevalence was found. An association between HPV infection and oral lesions was demonstrated in the studied population but the pathogenic influence of HPV infection remains unclear.

Aged↗
PubMedDate not supplied

Effects of long-term administration of cancer-promoting substances on oral subepithelial mast cells in the rat.

The role of oral subepithelial mast cells in the defence against tumours is a matter of controversy. The effect of established and suggested carcinogens, such as the carcinogen 4-nitroquinoline-N-oxide (4-NQO) and Herpes simplex virus type 1 (HSV-1), in combination with oral snuff on lower lip subepithelial mast cells (MC) was studied in rats. The rats were exposed to prolonged use of oral snuff. The test substances were administered in a surgically created canal in the lower lip of the rats. There were 15 rats in each test group and 10 rats in the control group. The amount of countable subepithelial mast cells decreased significantly when the rat oral mucosa was exposed to the oral carcinogen 4-NQO but the effect of oral snuff and HSV-1 infection was weak. Our findings suggest that mast cells play a role in immunological cell defence against chemical carcinogens. Further studies are needed to clarify the mechanisms.

4-Nitroquinoline-1-oxide↗
PubMedDate not supplied

Non-random chromosome rearrangements in herpes simplex virus type 1 transformed diploid CHEF cells.

The effects of Herpes simplex virus type 1 (HSV-1) on diploid, non-tumourigenic Chinese hamster embryo fibroblasts (CHEF/18-1D-3) were studied. Six independent lines transformed by HSV-1 alone or by HSV-1 in combination with acyclovir or aqueous tobacco extract were isolated. In contrast to uninfected CHEF/18-1D-3 cells, all transformants grew in soft agar and were tumourigenic in nude mice. Neither infectious virus nor viral antigens could be detected in any of the lines. Cytogenetic analysis revealed clonal chromosome abnormalities in all lines including trisomy for the long arm of chromosome 3 in five lines. In three of these the extra 3q was translocated onto 6p. All lines showed loss of the corresponding 3p arm. The remaining line had a hypodiploid stemline with loss of one chromosome 7. This line also showed a pronounced chromosomal instability with a multitude of mainly sporadic rearrangements. These results show that HSV-1 induced transformation and tumourigenesis in CHEF cells is associated with the induction of chromosome rearrangements, in particular trisomy for 3q.

Acyclovir↗
PubMedDate not supplied

Office cataract/IOLS.

Explore the source record for details and available documents.

Ambulatory Surgical Procedures↗