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Biomedical subjects

D Laufer

Publications and source records attributed to D Laufer.

At least 55 records · Page 3Linked to original sources
PubMed1998

Midface membranous bone lengthening: A one-year histological and morphological follow-up of distraction osteogenesis.

Midface bone lengthening was performed on three young, adult sheep using distraction osteogenesis following osteotomy of the maxilla and mounting of an extraoral fixation device. The midface was gradually distracted, 2 mm/day, for 21 days, up to approximately 40 mm. A marked midface advancement was noted. Following a further 6 weeks of retention, the device was removed and the animals were followed for 1 year. Biopsies specimens were taken from the distracted area at the end of the distraction period, after the additional 6 weeks of retention, and finally 1 year later. A nondistracted area of the maxillary bone served as control. The specimens were analyzed histologically, histochemically, and by scanning electron microscopy for the ultrastructural pattern, mineralization, mineral content, and approximate Ca2+ concentration. Clinically and radiographically, all sheep fully bridged the experimental gap. Histologically, at the completion of distraction, collagen bundles and slender bone trabeculae oriented in the direction of the distraction could be seen. At the end of the retention period, the trabeculae thickened noticeably and were partially replaced by mature lamellar bone. At the end of 1 year and after completion of the process of remodeling, the pattern of the distracted area resembled the control area. The mineralization, as reflected by quantitative calcium analysis, compared with the nondistracted area, demonstrated a low rate of mineralization after 3 weeks of lengthening, increased 6 weeks later, and after 1 year became nearly the same as in the nondistracted area. In conclusion, distraction osteogenesis provides satisfactory quantitative and structural new bone.

Animals↗
PubMed1998

Life-threatening complications and irreversible damage following maxillofacial trauma.

Trauma remains one of the principal causes of mortality in the western world, especially among young adults. The most serious immediate life-threatening complication following maxillofacial trauma is airway obstruction. The onset can be sudden, as with foreign body aspiration, or following soft-tissue damage that can lead at a later stage to airway-compromising oedema. The medical literature regarding facial trauma appears to support the hypothesis that maxillofacial trauma alone is rarely life threatening, or will not lead to life-threatening conditions unless associated with airway compromise. There are some causes of life-threatening complications following trauma to the maxillofacial region such as massive bleeding or undiagnosed cervical spine injury. However, there are some situations that may cause irreversible damage unless immediate operation is undertaken. The almost complete lack of reports dealing with death or irreversible damage in trauma involving the maxillofacial region prompted us to review and analyse the importance of immediate intervention following trauma to the maxillofacial region, in order to treat life-threatening complications and prevent irreversible damage.

Adolescent↗
PubMed1998

Metastatic follicular thyroid carcinoma to the maxilla.

We present a unique case of metastatic follicular thyroid carcinoma to the hard palate and the maxillary sinus, a case that to our knowledge has not been reported before. Various malignant tumours that metastize to the maxilla are reviewed, and the therapeutic approach to follicular thyroid carcinoma metastasis to that area is also discussed. Follicular thyroid carcinoma should be included in the list of tumours that metastasize to the maxilla.

Brachytherapy↗
PubMed1998

Radiological features of primary intra-osseous carcinoma of the jaws. Analysis of the literature and report of a new case.

OBJECTIVES: To analyse the clinical and radiological features of primary intra-osseous carcinoma of the jaws (PIOC). MATERIAL AND METHODS: Twenty-four cases (23 from the literature and one new case) of PIOC were reviewed. RESULTS: Patient's age at time of diagnosis ranged from 4-76 years, (mean 50 years). Male to female ratio was 1.7:1. Most lesions (79%) were in the mandible and of these, 95% were in the posterior area, approximately 70% of the maxillary lesions were in the anterior region and crossed the midline. In 87% of the cases PIOC was radiolucent; the remainder were mixed radiolucent-radiopaque lesions. The radiological borders were defined but none corticated in 57% of the cases and diffuse in 43%. The lesion was unilocular in 61% and not loculated in 35%. CONCLUSIONS: The variable radiological features of PIOC and its deceptive resemblance to odontogenic cysts and other tumours of the jaws suggests that despite its rarity, PIOC should be considered in the differential diagnosis of radiolucent lesions in the jaws.

Adolescent↗
PubMed1998

Schizophrenic disorder and social functioning.

Social functioning is assessed according to 84 questioned subjects with schizophrenic disorder and their 84 key figures. Schizophrenic subjects showed significant dysfunction in all reviewed areas of behaviour and social roles. Key figures of all schizophrenic subjects most often showed a positive attitude in regard to the future of the schizophrenic members of their family. In relation to social functioning of the schizophrenic subject and the attitude of family key figures there is a statistically significant difference as well as a relationship. Results of assessment confirmed the impact of family life on social functioning of the schizophrenic patient and stresses the importance of active family support in rehabilitation programs.

Adult↗
PubMed1997

[Distraction osteogenesis for hypoplastic facial bones].

Distraction osteogenesis is a well-known method for bone lengthening which stretches callus to generate new bone in the distracted area. The method was developed by Ilizarov for the lengthening of long enchondral bones. In recent years the method has also been applied to the facial bones and to the jaw.

Adolescent↗
PubMed1997

Osteoarthritis in the temporo-mandibular joint (TMJ) of aged mice and the in vitro effect of TGF-beta 1 on cell proliferation, matrix synthesis, and alkaline phosphatase activity.

The temporo-mandibular joint of aged mice develops osteoarthritic (OA) degenerative lesions. Adult chondrocytes have a low rate of cell replication, and cartilage repair potential is very limited. One of the major problems in OA is the low rate of matrix synthesis and the inability of the chondrocytes to exceed the rate of matrix degradation. These combined factors lead to the overall destruction of the cartilage as seen in OA. Cartilage degradation is mediated by elevated proteolytic activity of enzymes. Among the enzymes degrading cartilage are the metalloproteinases, stromelysin and collagenase. Other proteinases that may potentially participate in matrix degradation are the lysosomal enzymes cathepsin B, D, and L, and acid phosphatase. On the other hand, alkaline phosphatase (ALP) is an enzyme that has been shown to be a marker for anabolic activity in skeletal tissues such as bone and cartilage. The cartilage of the mandibular condyle in the T-M-J from aged mice reveals OA lesions. An overall reduction of cell proliferation and sulfated proteoglycan synthesis has been also shown in this joint. In the present study the effects of hTGF-beta on the stimulation of DNA and sulfated GAG synthesis and ALP activity were studied. Mandibular condyle cartilage obtained from 12-month-old ICR male mice were cultured in BGJb serum-free medium for 24-72 hours, supplemented with 0.1-10 ng/ml hTGF-beta 1. 3H-thymidine and 35S-sulfate were added for the last 24 hours of the culture and their incorporation into DNA and sulfated GAGs respectively, as well as the activity of ALP, were determined. Results indicated that hTGF-beta 1 enhanced the incorporation of both 3H-thymidine and of 35S-sulfate into cartilage cultures of aged mice, and also induced ALP activity. It thus appeared that in OA degenerating articular cartilage, the chondrocytes could be stimulated in vitro to proliferate and to synthesize new matrix, thus indicating induced anabolic activity in the tissue.

Alkaline Phosphatase↗
PubMed1997

[Facial trauma: characteristics and therapy].

This department was established 35 years ago. Since then, many patients with facial trauma, both soldiers and civilians, have been treated and extensive experience has been accumulated. From 1990 to 1995, 487 patients with facial trauma (18.6% of the patients in the department) where hospitalized and treated. 88.5% suffered from injuries which included facial bones, and the others from soft tissue injuries only. We summarize our experience, analyzing both the demographic and clinical characteristics of the injuries and the treatment administered. Based on our experience and the current literature, we present an overview of the issue.

Facial Injuries↗
PubMed1997

Comparison of in vitro response to growth hormone by chondrocytes from mandibular condyle cartilage of young and old mice.

In several aspects the features of aging resemble those of the state of growth hormone (GH) deficiency. Alterations of bone density and increased incidence of osteoporosis are some of the characteristics of aging that are similar to the findings in GH-deficient adults. Osteoarthritis (OA), a nonfatal condition predominating in old age, is characterized by the slowly progressive destruction of articular cartilage of joints. OA lesions are observed in the temporomandibular joint of ICR mice aged 7 months and older. The aim of the present study was to compare the response of chondrocytes from mandibular condyle cartilage of young and old mice to GH and to ascertain whether chondrocytes of old animals could still be stimulated to proliferate and to synthesize matrix components under the direct effect of GH in vitro. Mandibular condyles from young (3-month-old) and old (20-month-old) female ICR mice were cultured up to 72 hours in the presence of recombinant rat GH (0.1-100 ng/ml). 3H-Thymidine and 35S-sulfate were introduced during the last 24 hours of culture. Administration of GH appeared to increase only slightly the incorporation of 3H-thymidine in cartilage from young compared with the response in cartilage from old animals which was much more significant at 24 hours and 48 hours in culture. The same pattern was seen for the effect of GH on the incorporation of 35S-sulfate. Cartilage from young animals responded only slightly to GH, whereas a significant response was observed in cartilage from old animals after 24 and 48 hours in vitro. DNA contents were significantly elevated at all time intervals in both old and young animals, yet more significantly in cultures from old animals. In contrast, the activities of both alkaline and acid phosphatases were elevated at all time intervals in cultures from young animals, whereas no induction was observed in cultures from old animals. Tissue sections from cultures of old animals treated with GH (10 ng/ml, 48 hours) revealed atypical hypertrophic cells along the articular surface and also dark staining along the cartilage-bone interface. Exposure to tetracycline (10 mg/ml, 24 hours) resulted in an induced fluorescence, indicating enhanced mineralization in this region. Results of this study indicate that mandibular condyle cartilage from OA old mice responds in vitro to the addition of GH via anabolic activities of cell proliferation, sulfated proteoglycan synthesis, and possibly enhanced mineralization.

Aging↗
PubMed1997

Effects of transforming growth factor-beta 1 and interleukin-1 alpha on matrix synthesis in osteoarthritic cartilage of the temporo-mandibular joint in aged mice.

Osteoarthritic lesions were observed in the mandibular condyle cartilage of mice aged 7 months and older. These lesions appeared as fibrillations along the articular surface and were accompanied by reduced extracellular matrix synthesis and chondrocyte proliferation. Explants of mandibular condyle cartilage were cultured in serum-free BGJb medium supplemented with ascorbic acid (300 micrograms/ml), penicillin (100 U/ml) and streptomycin (100 micrograms/ml) for up to 72 h. Cultures were further supplemented with either hTGF-beta 1 (0.1-5.0 ng/ml) or human IL-1 alpha (40 U/ml). [3H]thymidine (2 microCi/ml) and [35S]SO4 (10 microCi/ml) were added to the culture medium for the last 24 h of culture and incorporation into DNA and sulfated proteoglycans, respectively, studied. The results indicated that protein and DNA contents, [3H]thymidine and [35S]SO4 incorporation, as well as the specific activity of alkaline phosphatase, were increased by TGF-beta 1. Addition of 1.0 or 5.0 ng/ml hTGF-beta 1 to the cultures for 48 h, had the most stimulatory effect on matrix synthesis and cell proliferation, whereas 0.1 ng/ml hTGF-beta 1 appeared to be inhibitory when compared to controls. Increased [35S]SO4 labeling of chondrocyte clusters was observed by autoradiography in tissue sections from cultures treated with TGF-beta 1 (1.0 and 5.0 ng/ml). In contrast, IL-1 alpha exerted inhibitory effects on cell proliferation and matrix synthesis. However, it induced the activity of acid phosphatase in these cultures. The results of the present study show that IL-1 alpha had catabolic effect on his tissue, while TGF-beta 1 enhanced proliferation and induced synthetic activity of the cartilage cells. Such action by TGF-beta suggests the existance of a possible repair process in osteoarthritic cartilage of the temporo-mandibular joint of aged mice.

Aging↗
PubMed1997

Cervicofacial actinomycosis: a diagnostic challenge.

Actinomycosis was first described as a clinical entity over 100 years ago. However, the fundamental characteristics of this entity have not been fully discussed, and major questions remain unanswered, such as the highly diversified pathogenicity of the phenomenon according to numerous published case reports and clarification of solid diagnostic criteria. Even the frequency of cervicofacial actinomycosis occurrence is unclear; some authors consider it to be rare and others to be common. We present 11 cases examined and treated in our department within the last 14 years along with a review of the literature. Diagnostic problems are emphasized, and a comprehensive overview of the entity is suggested.

Actinomycosis, Cervicofacial↗
PubMed1997

Sialochemical profile of X-irradiated major salivary glands in the rat.

The purpose of this study was to examine various sialochemical parameters in parotid (P) and submandibular (SM) secreted saliva of irradiated rats. Various doses of radiation from 2.5 to 15 Gy were administered to the head and neck region and the saliva was evaluated for its amylase activity and the concentration of sodium (Na), potassium (K) and total protein. Saliva samples containing equal amounts of proteins were also electrophoresed on separatory SDS gels, silver-stained and examined for possible qualitative alterations. The total protein concentrations of P saliva showed a radiation dose-dependent reduction at 3 days and 3 and 9 months following 15 Gy of 93%, 82% and 73% (p < 0.01), respectively. Forty days after the 15 Gy irradiation the reduction was not as severe (55%, NS). Three and 40 days post 15 Gy, amylase activity demonstrated a similar pattern of reduction, 98% and 89% (p < 0.01), respectively. In contrast to the P, no quantitative changes in the protein concentrations of the SM saliva were detected. As for the qualitative profiles of separated proteins, no radiation-induced changes were found for either P or SM at 3 and 40 days or 3 and 9 months, as compared with controls. The electrolyte concentrations were found to be flow-rate dependent. The Na concentrations of P saliva at 3 and 40 days following 15 Gy were reduced by 65% and 83% (p < 0.01), respectively. For SM saliva, the Na concentrations were reduced at 40 days by 58% (p < 0.05). The K concentration of P saliva increased at 40 days by 79% (p < 0.05). The data suggest that the various observed sialochemical changes could result from a reduction in the salivary flow rate and/or the number of surviving, normally functioning parenchymal cells. Thus, it is suggested that no salivary compositional alterations were directly induced by radiation but were secondary effects.

Amylases↗
PubMed1997

Spiral CT angiography: an alternative vascular evaluation technique for head and neck microvascular reconstruction.

Facial trauma and head and neck oncologic patients are often destined for extensive reconstructive procedures with microvascular free flaps due to ablative injuries or postoperative defects. The integrity and competence of the vasculature in the head and neck recipient site must be imaged and evaluated preoperatively as an essential prerequisite for the success of the reconstructive transfer. In a prospective study of five patients, we compared conventional angiography, the traditional technique, with a new vascular imaging modality--spiral computed tomographic (CT) angiography. One patient suffered from an extensive, ablative facial trauma, and the other four had undergone mandibulectomy as part of their oncologic therapy. In contrast to conventional angiography, spiral CT angiography is a noninvasive imaging technique, which we found to be characterized by much shorter patient examination time, avoidance of selective cannulation with its attendant risks, improved perception of anatomy, and the ability to rotate the reconstructed images in any plane to obtain the best view of any vessel in question. Disadvantages of spiral CT angiography in imaging vessels include the need for relatively large amounts of contrast medium, great dependence on the skill and experience of the operator, and the need for optimizing the timing of the contrast bolus and the scan.

Aged↗
PubMed1997

Traumatic bone cyst resembling apical periodontitis.

Among the pseudocysts of the jaws, the traumatic bone cyst is known as an asymptomatic lesion often noted unintentionally during routine radiographic examinations. The lesion neither devitalizes the teeth within its borders, nor does it cause resorption of their roots. The well-demarcated traumatic bone cyst often projects into the intraradicular septa and hence has been described as having scalloped borders. The following presentation is of a traumatic bone cyst that resembled periodontal pathology in its appearance.

Alveolar Bone Loss↗
PubMed1997

Complications of miniplate osteosynthesis in the treatment of mandibular fractures.

Miniplate osteosynthesis with 2.0-mm screws is being increasingly utilized in the treatment of mandibular fractures, midface fractures, zygomatic fractures, orthognathic surgery, and in craniomaxillofacial surgery. It enables better anatomic reduction, better stability of fracture lines, quick recovery and return of function. To examine complications related to its use, data were compiled from the preoperative, immediately postoperative, and 6-months' postsurgery examinations of 143 patients with isolated mandibular fractures. Sixteen of the patients (11.2%) presented with postoperative complications that were related to the miniplate system. The authors' experience and data support the theory that the complication rate is related more to the surgical approach and technique than to the time elapsed between injury and operation.

Adolescent↗
PubMed1997

Incidence and type of cervical spine injuries associated with mandibular fractures.

The incidence of facial fractures accompanied by spinal injuries, while low, is of significant concern to the craniomaxillofacial surgeon. There are conflicting reports on the association between facial fractures and concomitant spinal damage. This retrospective study of 424 patients with mandibular fractures examines the relationship of mandibular fractures and concomitant spinal injuries. The incidence of concurrent mandibular and cervical fractures was 2.6%, predominantly associated with motor vehicle accidents. The purpose of this study is to examine the incidence of cervical spine injury associated with mandibular fractures, in order to improve the diagnosis and treatment of spinal injury associated with mandibular fractures.

Accidents, Traffic↗