Modulation of Cellular Levels of Adenosine Phosphates and Creatine Phosphate in Cultured Primary Astrocytes.

Adenosine triphosphate (ATP) is the main energy currency of all cells, while creatine phosphate (CrP) is considered as a buffer of high energy-bond phosphate that facilitates rapid regeneration of ATP from adenosine diphosphate (ADP). Astrocyte-rich primary cultures contain ATP, ADP and adenosine monophosphate (AMP) in average specific contents of 36.0 ± 6.4 nmol/mg, 2.9 ± 2.1 nmol/mg and 1.7 ± 2.1 nmol/mg, respectively, which establish an adenylate energy charge of 0.92 ± 0.04. The average specific cellular CrP level was found to be 25.9 ± 10.8 nmol/mg and the CrP/ATP ratio was 0.74 ± 0.28. The specific cellular CrP content, but not the ATP content, declined with the age of the culture. Absence of fetal calf serum for 24 h caused a partial loss in the cellular contents of both CrP and ATP, while application of creatine for 24 h doubled the cellular CrP content and the CrP/ATP ratio, but did not affect ATP levels. In glucose-deprived astrocytes, the high cellular ATP and CrP contents were rapidly depleted within minutes after application of the glycolysis inhibitor 2-deoxyglucose and the respiratory chain inhibitor antimycin A. For those conditions, the decline in CrP levels always preceded that of ATP contents. In contrast, incubation of glucose-fed astrocytes for up to 30 min with antimycin A had little effect on the high cellular ATP content, while the CrP level was significantly lowered. These data demonstrate the importance of cellular CrP for maintaining a high cellular ATP content in astrocytes during episodes of impaired ATP regeneration.

Endogenous Energy Stores Maintain a High ATP Concentration for Hours in Glucose-Depleted Cultured Primary Rat Astrocytes.

Adenosine triphosphate (ATP) is the central energy currency of all cells. Cultured primary rat astrocytes contain a specific cellular ATP content of 27.9 ± 4.7 nmol/mg. During incubation in a glucose- and amino acid-free incubation buffer, this high cellular ATP content was maintained for at least 6 h, while within 24 h the levels of ATP declined to around 30% of the initial value without compromising cell viability. In contrast, cells exposed to 1 mM and 5 mM glucose maintained the initial high cellular ATP content for 24 and 72 h, respectively. The loss in cellular ATP content observed during a 24 h glucose-deprivation was fully prevented by the presence of glucose, fructose or mannose as well as by the mitochondrial substrates lactate, pyruvate, ß-hydroxybutyrate or acetate. The high initial specific ATP content in glucose-starved astrocytes, was almost completely abolished within 30 min after application of the respiratory chain inhibitor antimycin A or the mitochondrial uncoupler BAM-15, while these inhibitors lowered in glucose-fed cells the ATP content only to 60% (BAM-15) and 40% (antimycin A) within 5 h. Inhibition of the mitochondrial pyruvate carrier by UK5099 alone or of mitochondrial fatty acid uptake by etomoxir alone hardly affected the high ATP content of glucose-deprived astrocytes during an incubation for 8 h, while the co-application of both inhibitors depleted cellular ATP levels almost completely within 5 h. These data underline the importance of mitochondrial metabolism for the ATP regeneration of astrocytes and demonstrate that the mitochondrial oxidation of pyruvate and fatty acids strongly contributes to the maintenance of a high ATP concentration in glucose-deprived astrocytes.

Desmoplastic fibroma: report of rare lesion in unusual craniofacial location.

Desmoplastic fibroma (DF) is a benign but aggressive intraosseous tumor. These lesions are categorized as central tumors of bone. They are composed of small fibroblasts in a setting of abundant extracellular material, which is rich in collagen. DF represents fewer than 0.1% of all bony tumors. They can be found in any part of the skeleton. Based upon on our literature review, we believe this is the second reported case of desmoplastic fibroma occurring in the zygoma area.

Treatment of mandible fractures using resorbable plates with a mean of 3 weeks maxillomandibular fixation: a prospective study.

PURPOSE: In this study, a 2.5-mm resorbable plating system (Inion CPS, Tampere Finland) was assessed for the fixation of mandibular fractures with 3 weeks of maxillomandibular fixation. PATIENTS AND METHODS: Fifty mandibular fractures in 34 patients (32 males, 2 females) with a mean of 20.8 days of maxillomandibular fixation (MMF) were included in this study. The 2.5-mm resorbable plates were adapted along Champy's line of ideal osteosynthesis and secured with four 8 × 2.5 mm monocortical resorbable screws. All patients were followed for a minimum of 6 weeks with an average long-term follow-up of 10 months. The incidence of soft tissue infection, nonunion, malunion, malocclusion, osteomyelitis, nerve injury, and tooth damage was prospectively assessed. RESULTS: Primary bone healing was achieved in 100% of cases. Ten minor complications (20%) were observed: 5 soft tissue infections (10%), 4 plate dehiscences (8%), and 1 malocclusion (2%). No evidence of malunion, nonunion, osteomyelitis, plate fracture, or iatrogenic dental or nerve injury was noted; no readmission or reoperation was necessary. CONCLUSION: The Inion 2.5-mm resorbable plating system along Champy's line of ideal osteosynthesis plus 3 weeks of MMF is a viable option for the treatment of mandible fractures.

The efficacy of two UV toothbrush sanitization devices. A pilot study.

The authors conducted a study to evaluate the efficacy of two different toothbrush sanitization machines for household use and to determine if one machine's sanitizing power was superior to the other. Bacteria from the same individual were tested for six days using the same brand toothbrush and toothpaste at the same time of day. The toothbrushes were sanitized using the VIOlight and HIGH DENT. In 83% of cases with the VIOlight machine, the amount of bacteria decreased after being sanitized, whereas the HIGH DENT had a 100% decrease in bacteria. Eighty-three percent of brushes sanitized with HIGH DENT resulted in rare or no growth compared to only 33% of those sanitized with VIOlight. While both machines reduced the amount of bacteria present on the toothbrush, the HIGH DENT was 50% more effective than VIOlight in reducing the majority of bacteria on the toothbrush.

Transoral 2.0-mm locking miniplate fixation of mandibular fractures plus 1 week of maxillomandibular fixation: a prospective study.

PURPOSE: In this study, a 2.0-mm locking miniplate (LMP)/screw system was assessed in the treatment of mandibular fractures with a 1-week period of maxillomandibular fixation (MMF). PATIENTS AND METHODS: Fifty mandibular fractures in 34 patients with a mean of 6.97 days of MMF were included in the study. The 2.0-mm LMPs were adapted along Champy's line of ideal osteosynthesis and secured with four 8.0-mm locking monocortical screws. All patients were followed for a minimum of 6 weeks. The incidence of soft tissue infections, nonunion, malunion, malocclusion, osteomyelitis, nerve injury, and tooth damage was prospectively assessed. RESULTS: Primary bone healing was achieved in 98% of cases. Three complications (6%) were observed. Two minor complications of intraoral wound dehiscence and malocclusion were noted. A fibrous nonunion requiring 3 additional weeks of MMF was noted. No evidence of malunion, osteomyelitis, plate fracture, iatrogenic nerve injuries, or dental injuries was noted. CONCLUSIONS: A single 2.0-mm LMP placed along Champy's line of ideal osteosynthesis with four 8-mm monocortical locking screws plus 1 week of MMF fixation is a reliable and effective treatment modality for mandibular fractures.

Mediastinitis secondary to an odontogenic infection. A case report.

Infectious mediastinitis of odontogenic etiology is a rare occurrence in the United States. The mortality associated with descending necrotizing mediastinitis is estimated at 40% to 50%, even with advances made in management of such serious infections. The early diagnosis and aggressive treatment of odontogenic infections has made this entity relatively obsolete, but we have not been able to eliminate the disease process altogether. We report on a case that was managed successfully, albeit with a long, protracted course.

Transoral 2.0-mm miniplate fixation of mandibular fractures plus 2 weeks' maxillomandibular fixation: a prospective study.

PURPOSE: We conducted a study to assess the efficacy of intraoral treatment of mandibular fractures using a 2.0-mm miniplate and 2 weeks of maxillomandibular fixation (MMF). PATIENTS AND METHODS: Forty-four mandible fractures in 31 patients with a mean of 15 days of MMF were included in this study. A 2.0-mm miniplate was adapted along Champy's lines of ideal osteosynthesis and secured with four 8.0-mm monocortical screws. All patients were followed for at least 8 weeks after surgery. The incidences of bone or soft tissue infections, wound dehiscence, nonunion, malunion, malocclusion, plate fractures, and iatrogenic neurosensory deficits were prospectively evaluated. RESULTS: Primary bone healing was achieved in 100% of cases. No soft or hard tissue infection, malocclusion, malunion, nonunion, dental injuries, plate fracture, or iatrogenic nerve injuries were observed. Two (4.52%) minor complications-intraoral wound dehiscences-were noted. CONCLUSIONS: The use of a single 2.0-mm miniplate adapted along Champy's line of ideal osteosynthesis and stabilized with 4 monocortical screws plus 2 weeks of MMF was a viable treatment modality for mandibular fractures.