Xyloglucan fucosyltransferase, an enzyme involved in plant cell wall biosynthesis.

Cell walls are crucial for development, signal transduction, and disease resistance in plants. Cell walls are made of cellulose, hemicelluloses, and pectins. Xyloglucan (XG), the principal load-bearing hemicellulose of dicotyledonous plants, has a terminal fucosyl residue. A 60-kilodalton fucosyltransferase (FTase) that adds this residue was purified from pea epicotyls. Peptide sequence information from the pea FTase allowed the cloning of a homologous gene, AtFT1, from Arabidopsis. Antibodies raised against recombinant AtFTase immunoprecipitate FTase enzyme activity from solubilized Arabidopsis membrane proteins, and AtFT1 expressed in mammalian COS cells results in the presence of XG FTase activity in these cells.

Expression and Regulation of aERD2, a Gene Encoding the KDEL Receptor Homolog in Plants, and Other Genes Encoding Proteins Involved in ER-Golgi Vesicular Trafficking.

aERD2 and aSAR1 of Arabidopsis are functional homologs of yeast genes encoding proteins essential for endoplasmic reticulum (ER)-to-Golgi transport. The regulation of these secretory pathway genes in yeast, mammals, and plants is not known. High levels of expression of aERD2 and aSAR1 were observed in roots, flowers, and inflorescence stems, with the highest levels being detected in roots. The aSAR1 transcript levels were highest in young leaves and declined during leaf maturation. Low levels of aERD2 were detected in both young and fully mature leaves when compared with roots. In situ hybridization showed that trichomes accumulate more aERD2 transcript as the leaf expands, whereas aSAR1 is expressed equally in all leaf cell types. Treating plants with tunicamycin, a drug that blocks N-glycosylation in the ER, or with cold shock, known to block secretory protein transport, led to a marked accumulation of aERD2 and aSAR1 transcripts. The Arabidopsis ARF gene, which encodes a GTPase probably involved in Golgi vesicle traffic, was not affected by these treatments. This study is an essential first step toward understanding the regulation of genes that encode proteins involved in vesicular trafficking.

Impaired glucose-induced insulin response in transgenic mice overexpressing the L-phosphofructokinase gene.

The selective impairment of glucose-induced insulin secretion in NIDDM can be attributed to defects in the glucose-signaling system. An alteration in the activity of phosphofructokinase (PFK), a key enzyme in the glycolytic pathway, may play a role in the abnormal glucose-induced insulin secretion. In this study, we evaluated insulin secretion in transgenic (Tg) mice overexpressing the liver-type subunit of phosphofructokinase (PFKL). Three independently derived Tg-PFKL lines showed random and postprandial hyperglycemia with diminished acute insulin response following intravenous glucose tolerance load. Isolated islets of Tg-PFKL mice exhibited a shift to the right of the glucose insulin dose curve. However, the maximal insulin secretory capacity, as well as the potentiation effect by arginine, were retained. PFK activity in Tg-PFKL islets was increased by 30-70%, because of the overexpression of PFKL. Conceivably, a selective overexpression of the PFKL isoform in Tg-PFKL mice altered the enzymatic properties of the tetrameric PFK and thereby affected glucose metabolism. A similar phenomenon was previously observed in transfected PC12-PFKL cells. The data show that overexpression of PFKL in transgenic mice was associated with diminished glucose-induced insulin response and suggest a mechanism to explain the role of beta-cell PFK activity in glucose-induced insulin secretion.

Juvenile-Specific Localization and Accumulation of a Rhamnosyltransferase and Its Bitter Flavonoid in Foliage, Flowers, and Young Citrus Fruits.

1-2-Rhamnosyltransferase catalyzes the production of disaccharide-flavonoids that accumulate to 75% of dry weight. Vast energy is expended in a short time span to produce these flavonoids. The highest rhamnosyltransferase activities and immunodetected concentrations were observed in early development of Citrus grandis (pummelo), coinciding with up to 13% of fresh weight as naringin. The concentration of naringin in leaves, petals, receptacles, filaments, albedo, and flavedo drops drastically during development and correlates directly with a decrease in the activity and amounts of 1-2-rhamnosyltransferase. Anthers had minute rhamnosyltransferase activities and low concentrations of naringin. Conversely, high 1-2-rhamnosyltransferase activity and naringin concentrations appeared in both young and mature ovaries, as well as in young fruits. The total amounts of naringin in mature leaves decreased without detectable in vitro degradation of naringin in leaves. There was still a net accumulation of naringin in the albedo and flavedo of older fruit even though these tissues had only traces of 1-2-rhamnosyltransferase. Traces of enzyme synthesis in fruits, or import of the product from leaves, may explain the net accumulation of naringin in growing fruits. Unlike the late-expressed genes for glycosyltransferases in anthocyanin biosynthesis, the rhamnosyltransferases from Citrus are active only in juvenile stages of development.

Long-term results in maxillary deficiency using intraoral devices.

Cleft lip and palate patients often present maxillary retrusion and class III malocclusion after cleft repair. Maxillary distraction is a technique that can provide simultaneous skeletal advancement and expansion of soft tissue. Twelve patients with cleft maxillary deficiency due to cleft lip and palate were treated by Le Fort I osteotomy and two intraoral distraction devices that were activated after 4 days of latency period, 1mm per day on both sides. Long-term clinical and cephalometric evaluation of one and two years demonstrate stable results concerning the skeletal, dental and soft tissue relations. In this paper we discuss the advantages of distraction osteogenesis as a method for treatment of maxillary deficiency in cleft patients in terms of stability and relapse. The indications for maxillary distraction: (1) Moderate and severe retrusion that needs large advancement as in cleft lip and palate patients. (2) Forward and downward lengthening of the maxilla with no need for intermediate bone graft. (3) Growing patients. In conclusion, maxillary distraction in moderate or severe retrusion, as in cleft patients offers marked maxillary advancement with long-term stability.

Effects of lower third molar extraction on attachment level and alveolar bone height of the adjacent second molar.

Several conflicting findings have been published in previous literature regarding the effects of impacted third molar extraction on the periodontal health of the adjacent second molar; some authors have shown improvement of periodontal health distal to the adjacent second molar, whilst others have demonstrated loss of attachment and reduction of alveolar bone height. The purpose of this controlled clinical and radiographic study is to evaluate the long-term changes in periodontal health and alveolar bone height distal to the adjacent second molar following extraction of an impacted third molar. This split-mouth design study included 25 patients who underwent extraction of one mandibular impacted third molar (test), whereas the opposite tooth remained intact (control). Pre-operative and current-state panoramic radiographs were than scanned, and alveolar bone height was digitally measured on the distal aspect of the second molar on the test and control sides. Current-state clinical measurements were performed on both sides, and consisted of plaque index, gingival index, periodontal pocket depth, gingival margin position and clinical attachment level. Student's t-test for paired observations was used in order to examine the statistical significance of the differences in clinical parameters between the test and control sides and the differences in alveolar bone height pre- and post-operatively on both sides. Extraction of an impacted third molar resulted in a significant gain of alveolar bone height on the distal aspect of the adjacent second molar on the test side, whereas slight bone loss was noted on the control side. Even though the difference in plaque index between the test and control sides approached statistical significance following extraction, all clinical parameters seem to be unchanged. Further follow-up on clinical and radiological parameters is required for a more profound understanding of the long-term effects of third molar extraction on the periodontal health of the adjacent second molar.

Bilateral mandibular distraction for patients with compromised airway analyzed by three-dimensional CT.

The purpose of this study was to present the method of mandibular distraction osteogenesis in order to improve airway to respiratory distressed patients due to significant mandibular deficiency, and to present the quantitative volumetric evaluation of mandible and upper airway using three-dimensional-CT (3D-CT) before and after distraction. This study involved 12 patients aged 12 months to seven years with various complaints of Obstructive Sleep Apnea (OSA) such as noisy breathing during sleep, waking episodes, pauses in respiration and daytime somnolence. Some of them were considered tracheostomy candidates. All the patients underwent bilateral mandibular distraction under general anesthesia. 3D-CT of face and neck was performed before and after distraction and a quantitative volumetric evaluation of mandibular volume and airway volume was performed. The results reveal successful mandibular advancement with increase of mandibular volume by an average of 28.24% and increase of upper airway volume with a mean of 71.92%. Moreover, there were improved apnea index and oxygen saturation and elimination of OSA symptoms. In conclusion, the results demonstrate that following distraction osteogenesis of hypoplastic mandible the volume of the mandible and upper airway increases, eliminating symptoms of OSA and preventing tracheostomy.

Social behavior and off-target verbosity in elderly people.

This study investigated social behavior in older adults with varying levels of off-target verbosity (OTV). After screening 455 adults in Phase 1, 198 individuals were selected to participate in both a get-acquainted conversation and an experimental cues situation and to complete social and cognitive measures. Higher OTV participants had lower cognitive inhibitory scores, talked more, were less interested in their partners, and focused more on themselves. Their conversational partners were less satisfied. Age and cognitive functioning were not related to OTV scores or conversational style for low- and mid-range participants. Although high-OTV individuals talked less when exposed to social cues signalling boredom, they spoke more relative to other participants. Self-reported social behavior had little relation with OTV and conversational style, but higher OTV individuals were less accurate in judging videotaped social interactions. Gender differences in conversational behavior are also discussed.

Osseous reconstruction using a membrane barrier following marginal mandibulectomy: an animal pilot study.

BACKGROUND: Invasive and malignant tumors of the oral soft tissues adjacent to the mandible are often treated with partial resection of the osseous structure adjacent to the lesion (marginal mandibulectomy). Autogenous bone graft and composite bone grafts are being used to fill the osseous defects with various degrees of success. The aim of the present study was to explore the utilization of membrane barriers and the principle of guided bone regeneration to negotiate these defects. METHODS: Following the removal of P1, P2, and P3, experimental bilateral marginal mandibulectomy defects were created in 4 adult dogs. The bone segments (measuring 25 mm x 15 mm) were then removed. Each side was then randomly selected for either experimental (titanium-reinforced expanded polytetrafluoroethylene membrane, [ePTFE-TR]) or control (repositioning flaps) treatment. Postoperatively, the animals were put on soft diet, antibiotics, and analgesics. Sutures were removed under light sedation after 4 weeks, and the area was left to heal and mature for 4 to 6 months (mean 5.3 months). The animals were then sacrificed, and block sections of the mandible were obtained for macroscopic and histological evaluation. RESULTS: The size of the residual defect (the vertical distance between the most apical depression in the ridge and the horizontal line connecting the free gingival margins of the proximal teeth) in the experimental sites (6.10 +/- 1.00 mm) was much smaller compared to the controls (10.65 +/- 0.82 mm), which was statistically significant (P = 0.0127). Histomorphometric measurements of new bone formation (NBF) revealed a similar pattern: for the experimental sites, NBF was 8.08 +/- 0.85 mm compared to 4.99 +/- 0.61 mm in the controls. These differences were also statistically significant (P = 0.0257). CONCLUSIONS: A regenerative approach to large mandibular osseous defects has been described. If this new treatment modality is further substantiated in other independent studies, it might prove a useful tool in restoring the lost osseous structure associated with marginal mandibulectomy procedures.

Amine fluoride/stannous fluoride and chlorhexidine mouthwashes as adjuncts to surgical periodontal therapy: a comparative study.

BACKGROUND: Postsurgical mouthwashes are routinely used in clinical studies and also in daily clinical practice. Chlorhexidine gluconate (CHX) has long been the gold standard for supra-gingival chemical plaque control regimens. Amine fluoride/stannous fluoride (AmF/SnF2) formulations have also been extensively studied and shown to have an antibacterial effect and be useful as antiplaque agents. The antibacterial effect of AmF/SnF2 and its minimal extrinsic tooth staining make it a possible alternative to CHX as an adjunct to periodontal surgical therapy. The aim of this double-blind, controlled clinical trial was to evaluate and compare the combined effect of an AmF/SnF2 or a CHX mouthwash and surgical periodontal therapy on periodontal parameters. METHODS: Thirty-two patients with at least 3 pockets > or =5 mm in the same quadrant were selected for this study, following a hygienic phase of therapy. They were randomized into 2 treatment groups: surgical flap debridement and a postsurgical CHX mouthwash or surgical flap debridement and an AmF/SnF2 postsurgical mouthwash, performed twice daily for 3 weeks. Clinical measurements were taken at baseline and 3 and 12 weeks postsurgery. RESULTS: Both treatment modalities resulted in significant improvements in probing depth and clinical attachment level. There was no significant difference between groups in any of the recorded parameters. Staining index at week 3 in the CHX group was significantly higher than in the AmF/SnF2 group (P<0.05). However these differences leveled down at 12 weeks. CONCLUSIONS: Our results support the alternative use of an AmF/SnF2 mouthwash in plaque control management of patients following flap debridement surgery.

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.

Cyclosporine A-induced gingival hyperplasia pemphigus vulgaris: literature review and report of a case.

Gingival hyperplasia appears in 8% to 85% of patients treated with cyclosporine. Most studies show an association between oral hygiene status and the prevalence and severity of this gingival overgrowth. Thus, besides attempting to substitute this drug with another whenever possible, treatment usually involves maintenance of strict oral hygiene coupled with scaling and root planing and removal of iatrogenic factors. Sometimes a second treatment phase involving periodontal surgery is necessary. Cyclosporine-induced gingival overgrowth has been mainly described in post-organ transplant patients. The present case describes, for the first time, a severe form of cyclosporine-induced gingival overgrowth arising in a 15 year-old male with pemphigus vulgaris. Periodontal treatment included oral hygiene and scaling and root planing under local anesthesia. There was a significant reduction in gingival enlargement, as well as a reduction in plaque levels and inflammation. Cessation of drug administration, combined with continuous periodontal treatment, brought further improvement. This successful conservative treatment of cyclosporine-induced gingival overgrowth in a pemphigus vulgaris patient suggests that early diagnosis and comprehensive treatment of these lesions may yield good response and reduce the need for periodontal surgery.

Periodontal changes in liver cirrhosis and post-transplantation patients. I: clinical findings.

BACKGROUND: Cyclosporin A (CsA) is widely used to prevent liver transplantation failure. CsA-induced gingival overgrowth is a common side effect. However, the effect of cirrhotic liver disease, liver transplantation, and immunosuppressive therapy on the periodontium is yet unclear. The aim of the present cross-sectional study was to examine the effect of liver cirrhosis, transplantation, and immunosuppressive therapy on the periodontium. METHODS: The experimental group (LC) consisted of 13 liver cirrhosis patients. A second experimental group (PT) included 24 patients, post-liver transplantation, receiving immunosuppressive therapy. Seventeen healthy subjects formed a control group. The Ramfjord index teeth were recorded for plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL), and gingival overgrowth (GO). RESULTS: Mean PI and mean GI for the LC, PT, and C groups were not statistically different (P >0.05). Mean PD for the LC (3.32+/-0.24 mm) and PT group (3.41+/-0.13 mm) was significantly higher (P = 0.0001, ANOVA) compared to the C group (2.45+/-0.16 mm). Likewise, CAL for the LC (4.89+/-0.47 mm) and PT group (4.68+/-0.47 mm) was significantly higher (P = 0.001, ANOVA) than the C group (2.78+/-0.23 mm). Patients in the PT group exhibited the greatest mean GO scores (0.88+/-0.09) compared to the LC group (0.37+/-0.07) and the C group (0.09+/-0.02). All 3 groups were significantly different from each other (P = 0.0001) despite great variability within the groups. GO in the CsA-treated patients (1.1+/-0.09) was significantly higher (P = 0.0001) than in those treated with tacrolimus (0.57+/-0.1). CONCLUSIONS: Liver cirrhosis patients demonstrated greater pocketing and attachment loss compared to healthy matched controls. These same differences were observed in patients post-transplantation. Gingival overgrowth occurred as a result of the immunosuppressive therapy with CsA, while to a lesser degree with tacrolimus. Replacement of CsA by tacrolimus in patients manifesting gingival overgrowth might be recommended whenever possible to overcome this problem.

The effect of smoking and periodontal treatment on salivary composition in patients with established periodontitis.

BACKGROUND: The purpose of this study was to evaluate the effect of smoking on the periodontal status and the salivary composition in subjects with established periodontitis before and after periodontal therapy. METHODS: Our study group included 26 healthy subjects, 12 smokers and 14 non-smokers with established periodontitis. Clinical measurements and non-stimulated whole saliva were obtained and analyzed at baseline and after scaling and root planing. Smokers presented at baseline with significantly greater probing depth (4.16+/-0.26) compared to non-smokers (3.52+/-0.32) which was statistically significant (P = 0.0268); likewise, baseline clinical attachment level was greater in smokers (4.49+/-0.31 compared to non-smokers 3.87+/-0.13; P = 0.0620). Mean plaque index was also greater in smokers compared to non-smokers (0.86 and 0.65, respectively; P = 0.0834). Baseline pretreatment sodium values were significantly greater in non-smokers (14.36 mEq/l compared to 9.31 mEq/l in smokers; P = 0.0662); likewise non-smokers exhibited 50% greater salivary calcium levels (6.04 mg/100 ml compared to 4.32 mg/100 ml in smokers; P = 0.0133). RESULTS: Post-treatment probing depth and clinical attachment level were not different between smokers and non-smokers; this in spite of significant difference in plaque index in smokers (0.35 compared to 0.13 in non-smokers; P = 0.0135). Post-treatment, smokers had reduced calcium concentration (3.58 mg/100 ml compared to 5.11 mg/100 ml in non-smokers; P = 0.0438). Treatment affected albumin level in smokers only, consequently non-smokers had significantly greater salivary albumin concentration (1.1 mg/100 ml compared to 0.38 mg/100 ml in smokers; P = 0.0274). CONCLUSIONS: Subjects with established periodontitis exhibited elevated concentrations of salivary electrolytes and proteins. Within this study group, smokers exhibited greater disease level but reduced sodium, calcium, and magnesium concentrations. Smokers responded favorably to treatment. The clinical improvement eliminated the differences in salivary composition.

Primary gingival malignant melanoma. Report of 3 cases.

BACKGROUND: Malignant melanoma is rare in the oral cavity and accounts for less than 1% of all melanomas. Nevertheless, the disease can be fatal, and early diagnosis and treatment may improve prognosis dramatically. The purpose of this paper is to report 3 new cases of primary malignant melanoma of the oral cavity arising in the gingiva, and to review the literature regarding intraoral melanoma. METHODS: Three cases are presented. One case was in the right mandibular molar area; the second in the right maxillary canine-premolar area; and the third in the left mandibular canine-premolar region. All patients were treated surgically, with postoperative radiotherapy. RESULTS: The first patient lived for 2 years and the second for 3 years before distant metastases were diagnosed from which they subsequently died. The third patient was lost from follow-up after 18 months. CONCLUSION: Primary oral malignant melanoma is a deadly disease. Early suspicion of this disease will allow prompt treatment and increase the prognosis for these patients.

Low lead level in teeth in Israel.

A total of 180 sound teeth extracted from people living mainly in Northern Israel and some in the center of the country, aged 14-75 years, were analysed by graphite furnace atomic absorption spectrophotometer. The average lead level in teeth roots ranged between 1.61-25.72 micrograms/g dry root, according to the donor's age. This low level was measured in all the regions which were checked, with no significant differences between them, despite differences in levels of motor traffic rates. Based on the low lead level in teeth, we assume that no further reduction in the lead level in gasoline is needed, as long as motorization rate or gasoline consumption does not change significantly.

Burkitt's lymphoma of the oral cavity in Israel.

The clinical presentation of Burkitt's lymphoma in the maxillofacial area is variable. The objective of this study is to review and analyse all cases of Burkitt's lymphoma with oral or maxillofacial involvement diagnosed in our department. A retrospective review of patients with Burkitt's lymphoma in the facial area between the years 1978 and 1997 was undertaken. The patients, 8 male and 5 female, were from 7 to 50 years old (mean 15.3 years). Six patients were Stage I and 7 were Stage II. Five had abdominal involvement and 2 lymph node involvement besides the maxillofacial presentation. Three tumours were in the mandible, 3 in both mandible and maxilla, 2 in the palate, and 5 in the maxilla alone. In 5 patients the tumour presented as a facial swelling, in 3 as an exophytic mass, in 2 as an ulcer, 1 case presented as a hyperplastic lesion, and 2 were periapical lesions. Complaints included pain (7), swelling (5), and sensory disturbance (2). EBV titres were positive in 4 patients. Abdominal involvement was only seen in patients under 12 years old. All patients were treated with chemotherapy, while adjuvant radiotherapy was indicated in 3 cases. Follow-up of 1-20 years revealed a 2-year survival rate of 61.5%. It seems that the Israeli disease is between that of the African and American types, when considering age distribution.

Alveolar ridge augmentation by distraction osteogenesis.

Distraction osteogenesis is an alternative method for reconstructing atrophic alveolar bone. Fourteen patients underwent vertical alveolar distraction by the LEAD SYSTEM-Endosseous Alveolar Distraction System (Stryker Leibinger, Kalamazoo, MI). An alveolar segmental osteotomy was carried out and the vertical distraction device was mounted. In patients with an extensive alveolar defect, two distraction devices were placed in order to better control the vector of elongation in both bone edges. The distraction was started on the fourth postoperative day at a rate of 0.8 mm/day for 10-16 days, followed by a consolidation period of 60 days. Vertical distraction osteogenesis (VDO) was completed successfully in all patients with segment lengths in the range of 8 to 13 mm and with an average of 10.3 mm. Subsequently, the devices were removed and 23 threaded titanium dental implants were placed for osteointegration. Earlier mineralization in the vertically distracted area was seen radiographically during the consolidation period. In a follow up of 6-20 months after the distraction, 22 implants were successfully osteointegrated while one implant failed due to improper distracted segment stability. As a result of alveolar distraction, a segment of mature bone was transported vertically in order to lengthen the crest for better implant anchorage, either for aesthetic purposes or for functional prosthetic requirements. The main advantages of VDO are: (1) augmentation of alveolar bone height with new bone formation and simultaneous expansion of the soft tissues; (2) no bone harvesting is necessary; (3) the technique has a lower morbidity rate compared with conventional techniques; (4) it makes the insertion of longer dental implants feasible.

Use of the 'shark-fin' osteotome in separation of the pterygomaxillary junction in Le Fort I osteotomy: a clinical and computerized tomography study.

Le Fort I osteotomy fails in many cases to completely separate the pterygomaxillary junction and often results in fractures of the pterygoid bone and the tuberosity, which subsequently can cause complications. The objectives of this study were to describe the specifically developed Laster 'shark-fin' osteotome and to compare its use to other methods of pterygomaxillary dysjunction. Pterygomaxillary dysjunction was performed in 10 adult patients requiring Le Fort I osteotomy. In one randomly chosen side of the maxilla, the Obwegeser osteotome was used, while the Laster 'shark-fin' osteotome was used on the opposite side. A postoperative computerized tomography of the separation at the pterygomaxillary junctions revealed that in all sites treated with the Laster 'shark-fin' osteotome, a complete or almost complete separation was obtained, whereas the use of the Obwegeser osteotome resulted in five sites with fractures of the maxillary tuberosity and three with high-level fractures of the pterygoid plates (P<0.001). Comparing these findings with the literature, we concluded that the Laster 'shark-fin' osteotome is preferable for separating the pterygomaxillary junction in Le Fort I osteotomy.

Surgically-assisted orthopedic protraction of the maxilla in cleft lip and palate patients.

Fourteen children, aged 8 to 13 years, with unilateral or bilateral cleft lip and palate, were treated by an incomplete Le Fort I osteotomy without down-fracturing the maxilla, followed by traction of the maxilla by face mask for twelve weeks. Our results revealed a mean maxillary forward movement of 7.2 mm after three weeks of traction, followed by a retention period of nine weeks for callus maturation. There was an associated minor downward movement of the maxilla that caused a slight increase in the lower facial height, which improved the facial esthetics of the patients. The advantages of this method are: i) it allows for early skeletal advancement of the maxilla with new bone formation in the osteotomy line, ii) there is no need for inter-maxillary fixation of young patients and no need for rigid fixation of the maxilla by miniplates that can damage teeth buds and roots at this age, and iii) it can be used in young patients to improve esthetic appearance, an important factor in the psychological development of adolescents.