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P Reher

Publications and source records attributed to P Reher.

10 recordsLinked to original sources
PubMed2003

Measurement of nitric oxide in temporomandibular joint saline aspirates.

Temporomandibular joint (TMJ) saline aspirates, obtained from the upper joint space of 17 patients undergoing TMJ arthroscopy under general anaesthesia were assayed for the presence of nitrite, a stable metabolite of nitric oxide by a spectrophotographic method using the Griess reaction. Measurable levels of nitrites were found in the saline aspirates of both symptomatic and asymptomatic joints. There was no statistically significant difference between the two sides. The presence of nitric oxide metabolites in the asymptomatic joints has not been previously reported in the literature. This finding may represent a latent disease process in the symptomless joint.

Adult↗
PubMed2002

Ultrasound stimulates nitric oxide and prostaglandin E2 production by human osteoblasts.

We have previously shown that the therapeutic range of ultrasound heals osteoradionecrotic bone and induces bone formation in vitro. It is well established that nitric oxide (NO) and prostaglandins are crucial early mediators in mechanically induced bone formation. The therapeutic range of ultrasound may act in the same way; therefore, we have investigated the effect of the therapeutic range of ultrasound on NO induction and prostaglandin E(2) (PGE(2)) production in vitro. Two ultrasound machines were evaluated, "traditional" (1 MHz, pulsed 1:4, tested at four intensities) and a "long-wave" (45 kHz, continuous, also tested at four intensities) devices. Ultrasound was applied to human mandibular osteoblasts for 5 min, and incubated at 37 degrees C for up to 24 h. The control group (sham insonated) was treated in the same way. NO was determined by measuring the nitrite concentration in the culture media colorimetrically, and PGE(2) was assayed by radioimmunoassay. Ultrasound produced a significant increase in both induced nitrite and PGE(2) production. The NO synthesis appeared to be via inducible NO synthase (iNOS) on the basis of the time course and levels of nitrite obtained, although the inhibition of other NOS isoforms by aminoguanidine cannot be excluded. PGE(2) synthesis appeared to be via COX-2. With the 45 kHz machine, a significant increase in NO was achieved at three intensities, 5, 30, and 50 mW/cm(2). The 1 MHz machine stimulated the synthesis of both NO and PGE(2), but was significant at only one dose (0.1 W/cm(2(SAPA))). There was no difference between the two machines with regard to PGE(2) synthesis. The time-course experiment revealed peak production to be 12-18 h for both NO and PGE(2). The therapeutic range of ultrasound stimulates both NO and PGE(2) synthesis by human osteoblasts, and the 45 kHz machine appeared to be more effective than the traditional short-wave length. These results may reflect the healing effect of ultrasound on fractures and osteoradionecrosis.

Cells, Cultured↗
PubMed1999

Effect of ultrasound on the production of IL-8, basic FGF and VEGF.

Therapeutic angiogenesis is the controlled induction or stimulation of new blood vessel formation to reduce unfavourable tissue effects caused by local hypoxia and to enhance tissue repair. The effects of ultrasound on wound healing, chronic ulcers, fracture healing and osteoradionecrosis may be explained by the enhancement of angiogenesis. The aim of this study was to identify which cytokines and angiogenesis factors are induced by ultrasound in vitro. Two ultrasound machines were evaluated, a "traditional" (1 MHz, pulsed 1:4, tested at four intensities), and a "long wave" machine (45 kHz, continuous, also tested at four intensities). The ultrasound was applied to human mandibular osteoblasts, gingival fibroblasts and peripheral blood mononuclear cells (monocytes). The following cytokines and angiogenesis factors were assayed by ELISA techniques: interleukin-1beta(IL-1beta), IL-6, tumour necrosis factor alpha (TNF-alpha), IL-8, fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF).A slight stimulation of IL-1beta was noted in all cell types. There was no difference in the IL-6 and TNF-alpha levels. The angiogenesis-related cytokines, IL-8 and bFGF, were significantly stimulated in osteoblasts, and VEGF was significantly stimulated in all cell types. Both ultrasound machines produced similar results, and the optimum intensities were 0.1 and 0. 4 W/cm2 (SATA) with 1 MHz ultrasound, and 15 and 30 mW/cm2 (SATA) with 45 kHz ultrasound.The results show that therapeutic ultrasound stimulates the production of angiogenic factors such as IL-8, bFGF and VEGF. This may be one of the mechanisms through which therapeutic ultrasound induces angiogenesis and healing.

Angiogenesis Inducing Agents↗
PubMed1999

In vitro effects of therapeutic ultrasound on cell proliferation, protein synthesis, and cytokine production by human fibroblasts, osteoblasts, and monocytes.

PURPOSE: The aim of this study was to evaluate several in vitro effects of ultrasound that could revert or prevent the hypoxia, hypovascularity, and hypocellularity observed in osteoradionecrosis. MATERIALS AND METHODS: Two different ultrasound machines were evaluated, a "traditional" (1 MHz, pulsed 1:4) and a "long wave" (45 kHz, continuous) machine, tested at various intensities. Ultrasound was applied to human gingival fibroblasts, mandibular osteoblasts, and monocytes. The assays performed were cell proliferation (DNA synthesis), collagen and noncollagenous protein (NCP) synthesis, and cytokine production (ELISA) involving interleukin (IL) 1 beta, IL-6, and IL-8, tumor necrosis factor alpha (TNF alpha), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF). RESULTS: Both ultrasound machines induced increased cell proliferation in fibroblasts and osteoblasts, between 35% and 52%. The collagen and NCP synthesis were also significantly enhanced to levels up to 112%, the best results being with the 45-kHz machine. The ELISA results showed a slight stimulation of IL-1 beta by all cell types; there was no difference in IL-6 and TNF alpha levels. The angiogenesis-related cytokines evaluated were significantly stimulated: IL-8 and bFGF production was enhanced in osteoblasts, and VEGF production was stimulated in all three cell types. Both ultrasound machines produced the same results, with the recommended intensities being 15 and 30 mW/cm2(SA) for the 45-kHz ultrasound, and 0.1 and 0.4 W/cm2(SAPA) for the 1 MHz ultrasound. CONCLUSIONS: Therapeutic ultrasound induces in vitro cell proliferation, collagen/NCP production, bone formation, and angiogenesis. These findings support its use in prospective clinical trials for the prevention and treatment of osteoradionecrosis.

Analysis of Variance↗
PubMed1998

Therapeutic ultrasound for osteoradionecrosis: an in vitro comparison between 1 MHz and 45 kHz machines.

Mandibular osteoradionecrosis is a serious chronic complication which may follow radiotherapy. Therapeutic ultrasound is a highly effective, inexpensive and readily available means of promoting revascularisation and healing. 'Long wave' ultrasound increases penetration depth and, therefore, seems to be more appropriate than traditional high frequency ultrasound. The aim of this study was to compare a new treatment using 45 kHz with the current standard 1 MHz machine. A traditional 1 MHz machine, pulsed 1:4, at intensities of 0.1, 0.4, 0.7 and 1.0 W/cm2(SAPA) was compared with a long wave machine, 45 kHz, at intensities of 5, 15, 30 and 50 mW/cm2(SA). The ultrasound was applied to human gingival fibroblasts and mandibular osteoblasts in vitro. Cell proliferation (DNA synthesis) and collagen and non-collagenous protein synthesis assays were performed, using radiolabelled thymidine and proline, respectively. Controls were sham-insonated and all readings were given as a percentage of controls. Fibroblast proliferation increased by 47% at 0.7 W/cm2 (1 MHz) and by 43% at 50 mW/cm2 (45 kHz), and osteoblast proliferation increased by 52% at 1.0 W/cm2 (1 MHz), and by 35% at 30 mW/cm2 (45 kHz). Fibroblast collagen production increased by 48% at 0.1 W/cm2 (1 MHz), and by 44% at 15 mW/cm2 (45 kHz) and osteoblast collagen production increased by 55% at 0.1 W/cm2 (1 MHz) and by 112% at 30 mW/cm2 (45 kHz). Long wave ultrasound was, therefore, capable of inducing a comparable or even higher enhancement of bone formation compared with traditional ultrasound, which, with its greater penetration, may accelerate the healing effect of ultrasound on osteoradionecrosis. The suggested intensity for 45 kHz ultrasound is 30 mW/cm2.

Cell Division↗
PubMed1997

The stimulation of bone formation in vitro by therapeutic ultrasound.

A controlled study was performed to evaluate the effects of different ultrasound (US) intensities on 5-day-old mouse calvaria bone in tissue culture. A special technique to apply the US was developed, and the following parameters were measured: collagen and noncollagenous protein (NCP) synthesis (bone formation), and temperature change. It was found that ultrasound at 0.1 W/cm2 (SATA), pulsed 1:4, 3 MHz, 5 min, significantly stimulates bone formation (i.e., the synthesis of collagen and NCP) (p < 0.001 and p < 0.01). However, pulsed ultrasound at higher doses (1.0-2.0 W/cm2 (SATA), pulsed 1:4, 3 MHz, 5 min) significantly inhibited the synthesis of both collagen and NCP (p < 0.05). The temperature measurements showed a maximum rise of 1.8 degrees C [at 2.0 W/cm2 (SATA)] and no detected rise at 0.1 W/cm2 (SATA), suggesting that the effects in this study were primarily nonthermal. These results may reflect the healing effect of US on fractures and osteoradionecrosis and reinforces the use of low intensity US regimens [0.1 W/cm2 (SATA)] in clinical practice.

Animals↗
PubMed1994

Miniplates in the frontozygomatic region. An anatomic study.

A study of the frontozygomatic region (FZ) to determine an anatomic basis for the use of miniplates in this area was done. Plaster models were obtained from 35 adult skulls and were sectioned at six defined points. Osseous thickness measurements were made perpendicularly to the bone surface. Measurements to determine the risk of penetrating the cranial cavity were also done. The results show that above the FZ suture 5-mm screws should be used. At the two points below the suture, 7-mm screws can be used. The risk of penetrating to the cranial cavity occurs 10 mm above the suture. The diploe thickness at the level of the anterior cranial fossa floor indicates the use of a 7-mm screw at a distance 13.5-18.5 mm from the suture and 5-mm screws above 18.5 mm.

Adult↗
PubMedDate not supplied

[Idiopathic facial pain. Part 2: Treatment and prognosis].

The present paper introduces a new concept in the physiopathology and treatment of the called "temporomandibular disfunction". This paper was divided into two parts, the first explained the definition, etiology and hypothesis of the idiopathic facial pain. In this second part, its treatment, prognosis and recommendations are explained. The treatment consists basically in counselling, and, in a second stage, the use of tricylic antidepressants or similar drugs is used. Occlusal devices are some times used, but have been of less value. Arthroscopy can be used in resistant patients, and surgery is usually not indicated. The present management is based on a working model developed in this department and in other world centres, and is revolutionising the clinical management of the patients with idiopathic facial pain.

Facial Pain↗
PubMedDate not supplied

[Idiopathic facial pain--Part 1: Definition, classification and etiology].

The present paper introduces a new concept in the physiopathology and treatment of the called 'temporomandibular dysfunction'. This paper was divided into two parts, this first explaining its definition, aetiology and hypothesis of the idiopathic facial pain. The second part, will mention its treatment, prognosis and recommendations. Under this new view, this 'dysfunction' is part of the called Idiopathic Facial Pain. The idiopathic facial pain is didactically subdivided in (1) facial artromialgia, (2) atypical facial pain, (3) atypical odontalgia and (4) oral dysestesia. Occlusal factors are less important in its aetiology, and psychological and biochemical factors are more recognised. Correct diagnosis is essential, and a full history, including psychological and social aspects is very important. The present management is based on a working model developed in this department and in other world centres, and is revolutionising the clinical management of the patients with idiopathic facial pain.

Facial Pain↗