Maxillary sinus augmentation: histomorphometric analysis of graft materials for maxillary sinus floor augmentation

OBJECTIVE: To compare efficacy and tolerance of recombinant interferon alfa-2b in the treatment of anti-HCV-positive chronic active hepatitis (CAH) in subjects aged 65 years and above with those less than 65. DESIGN: A randomized controlled trial. SETTING: Outpatients in two hospitals. PATIENTS: 65 consecutive outpatients with anti-HCV-positive CAH for 1 to 30 years, having basal aminotransferase levels at least twice the normal value. Those 65 and over were randomized to an interferon group (A, n = 22) or a no-treatment group (B, n = 22). All those under 65 received interferon (group C, n = 21). INTERVENTION: Interferon at a dose of 3 mU 3 times a week for a 6-month period. A normalization of serum aminotransferase levels was considered a positive response to therapy. RESULTS: Response to therapy was positive in 62% of the treated elderly compared to 57% of the adults (P = 0.85). The two groups of responders showed a common highly significant reduction of aminotransferase (P < 0.001). Side effects were similar in elderly and young. Two untreated elderly showed spontaneous normalization of aminotransferase. CONCLUSION: Interferon in anti-HCV-positive CAH is useful in the elderly, allowing normalization of aminotransferase, improvement of the histology and remission of the disease in 62% of the cases. Side effects seem to be independent of age. Further studies are required to assess both duration of remission and usefulness of cyclic therapy in previous responders.     

Histologic changes in the sinus membrane after maxillary sinus augmentation in goats

PURPOSE: Previous studies have reported on the morphologic aspects of bone regeneration after maxillary sinus grafting. However, no previous studies have examinated the morphology of the maxillary sinus mucosa after grafting. The purpose of this study was to evaluate the histologic changes in the lining membrane after sinus augmentation. MATERIALS AND METHODS: A unilateral osteotomy of the lateral maxillary wall, medial displacement of the bony segments, and elevation of the sinus mucosa were performed in 12 goats. An autogenous bone graft combined with coralline particles was placed on the floor of the sinus in three animals, and coralline particles alone were placed in three other goats. Six goats were not grafted and were used as controls. Samples were harvested at 2.5, 4.5, and 6.5 months. The maxillary sinus mucosa was examined using light microscopy and scanning and transmission electronic microscopy. RESULTS: The coralline particles were surrounded by fibrous connective tissue when used alone. The addition of iliac crest bone to the coralline particles stimulated bone formation. After the sinus augmentation, the mucosal lining showed a lack of glands in the lamina propria, and the epithelium showed an increase in goblet cells. CONCLUSION: It was concluded that the sinus mucosa undergoes physiologic adaptations and remains healthy and free of chronic sinusitis after maxillary sinus grafting.     

A new animal model for maxillary sinus floor augmentation: evaluation parameters

Stress mediators, CRF-41 and vasopressin known to be synthesized in, and released from the parvocellular neurosecretory neurons of the hypothalamic paraventricular nucleus (PVN) are essential to release adrenocorticotropin (ACTH) in response to stress. In addition, suckling-induced prolactin (PRL) release also depends on the integrity of the PVN. In the present study, ether stress-induced adrenocorticotrop hormone (ACTH) and prolactin (PRL) release was studied 2, 5 and 42 days after placing lesions in the hypothalamic paraventricular nucleus (PVN) of male rats. Ether-induced ACTH secretion was strongly inhibited 2 and 5 days after lesions whereas 6 weeks later the lesion induced inhibition was fading. In contrast, PVN lesion failed to inhibit ether-induced PRL release at any time studied. The results suggest that contrary to previous suggestions the peptidergic neurons essential for stress-induced PRL release are outside the PVN.     

Wear analysis of a retrieved hip implant with titanium nitride coating

There is increasing interest in using surface modification technology to improve the wear properties of titanium alloy and limit articular surface wear of metal and polyethylene components. This report details the in vivo wear performance of titanium nitride coating on a retrieved hip implant obtained postmortem from a low demand patient 1 year after total hip arthroplasty. Analysis of the well-functioning implant revealed that wear debris can originate from a titanium nitride coated femoral head, as delaminated surface asperities, and manifest as adhesive wear on the articular surface. The wear observed on this implant indicates that rigorous testing and evaluation of titanium nitride coating technology should be conducted prior to widespread use on total joint implants.     

Cross-section radiographic analysis of 10 retrieved titanium alloy press-fit femoral endoprostheses

Genetic diagnosis of hereditary tumors has progressed extensively and contributed to the presymptomatic testing for mutation carriers. This evolution of genetic testing for cancer susceptibility leads to improved prevention and early detection of cancers. However, the benefits and limits of testing, and the range of prevention and treatment are different in each hereditary tumor. The American Society of Clinical Oncology (ASCO) made the statement on genetic testing for cancer susceptibility and showed three categories for consideration of cancer predisposition testing. They recommend that genetic testing should be offered only for the categories including well-defined tumors. We described the characteristics of hereditary tumors in the three categories and discussed the significance of genetic testing for each tumor. In conclusion, genetic testing for cancer susceptibility should be applied only for subsets of hereditary syndromes, and it is important to continue the analysis of the significance (frequency or penetrance) of mutations of cancer predisposition genes and to make clear the genotype-phenotype and other correlations.     

The influence of maxillary sinus augmentation on the success of dental implants through second-stage surgery

OBJECTIVE: To study the familial occurrence of hemangioblastoma of the central nervous system and to search for an effective way to diagnose and manage the disease. METHODS: From 1974 to 1993, six patients with hemangioblastoma with family history underwent surgical treatment at our hospital. Computerized tomography (CT) or magnetic resonance imaging (MRI) technique was used for the diagnoses before operation. RESULTS: Each patient had more than two relatives with hemangioblastoma. Multiple lesions were found in two of the six familial hemangioblastoma cases. All the patients recovered well after operation. So far, no victims have been discovered in the third generation. CONCLUSIONS: The high occurrence rate of familial hemangioblastoma cases suggests an involvement of hereditary factors. We need a long follow-up study on the descendants of familial hemangioblastoma patients. MRI is of diagnostic value in determining the location and nature of hemangioblastoma in both brain and spinal cord. A thorough examination is necessary for hemangioblastoma patients, and microsurgery is important in removing the tumor.     

Unusual metastasis of hypernephroma in the maxillary sinus

OBJECTIVES: To determine the predictive value of intraoperative threshold stimulus for facial nerve outcome and the prevalence and prognostic value of persistent trains of activity and frequent spontaneous or mechanically induced contractions during acoustic neuroma surgery. STUDY DESIGN: Prospective recording and subsequent review of facial nerve activity. SETTING: Tertiary referral centre. PATIENTS AND METHODS: Consecutive patients undergoing acoustic neuroma surgery. Intraoperative facial nerve activity was digitised and stored on a personal computer for future analysis. Operative events were flagged. Recordings were available in 27 patients. MAIN OUTCOME MEASURES: Frequent mechanically induced contractions (< 20), prolonged trains of facial nerve activity (total time > 199 seconds), and facial nerve brainstem stimulus threshold were correlated with facial nerve outcome. RESULTS: A brainstem stimulus threshold > 0.1 mA was significantly associated with intermediate or poor facial nerve function (House-Brackmann grade > 2) on the sixth postoperative day, at 1 month and 6 months. Patients with normal or near-normal facial function on the first day and a threshold of > 0.1 mA were significantly more likely to develop a delayed facial nerve palsy. Frequent contractions were noted in 74% of patients and persistent train activity in 59%. Neither was predictive of facial nerve outcome. CONCLUSIONS: An elevated brainstem threshold is helpful in predicting delayed facial nerve palsy and suboptimal facial nerve outcome. Persistent train activity and frequent contractions, do not have major prognostic significance.     

Gallium-67 scanning in the differentiation of maxillary sinus carcinoma from chronic maxillary sinusitis

Gallium-67 scans of 25 patients in whom the clinical symptoms and radiographic findings were suggestive of either maxillary sinus carcinoma or chronic sinusitis proved to be valuable in the differentiation between the two disease processes. Those patients with carcinoma had positive scans, while those with sinusitis had either negative or only weakly positive scans.     

Follicular adenocarcinoma of the thyroid in the maxillary sinus

No reports of metastatic thyroid carcinoma in the maxillary, ethmoid, or sphenoid sinuses can be found in the literature. A woman with severe posterior epistaxis was examined recently. She had undergone a partial lobectomy for a thyroid tumor 16 years previously. Hemorrhagic thyroid tissue was in the maxillary sinus. The results of subsequent examinations indicated thyroid deposits in the lung and spine. The patient received radioactive iodine, 100 MCi. Her lung and spine deposits lysed, and she experienced no further epistaxis. Thyroid carcinoma's ability to metastasize to a paranasal sinus is documented here. Epistaxis after a thyroidectomy for cancer now must be considered an unusual clinical manifestation of metastatic spread, unless otherwise proved. The differential diagnosis of epistaxis must now include thyroid carcinoma metastatic to the sinonasal tract.     

Ultrasonographic bedside evaluation of maxillary sinus disease in mechanically ventilated patients

GABA modulates dopamine concentrations in the nucleus accumbens and corpus striatum. Using in vivo microdialysis techniques we examined this modulatory role and the extent to which three different GABAergic drugs can attenuate cocaine's ability to increase extracellular dopamine concentrations and gross locomotor activity. Ethanol, lorazepam (Ativan), and gamma-vinyl GABA (GVG) significantly and dose-dependently attenuated cocaine-induced dopamine release in the corpus striatum of freely moving animals. Unlike ethanol or lorazepam, however, GVG is not a sedative hypnotic in the doses used, and hence the strategy of selectively increasing GABAergic activity by suicide inhibition of the catabolic enzyme, GABA-transaminase, offers the unique advantage of attenuating cocaine-induced dopamine release without the apparent side effects typically associated with sedative hypnotics.     

Effects of guided bone regeneration around commercially pure titanium and hydroxyapatite-coated dental implants. II. Histologic analysis

The purpose of this study was to determine which treatment of a large osseous defect adjacent to an endosseous dental implant would produce the greatest regeneration of bone and degree of osseointegration: barrier membrane therapy plus demineralized freeze-dried bone allograft (DFDBA), membrane therapy alone, or no treatment. The current study histologically assessed changes in bone within the healed peri-implant osseous defect. In a split-mouth design, 6 implants were placed in edentulous mandibular ridges of 10 mongrel dogs after preparation of 6 cylindrical mid-crestal defects, 5 mm in depth, and 9.525 mm in diameter. An implant site was then prepared in the center of each defect to a depth of 5 mm beyond the apical extent of the defect. One mandibular quadrant received three commercially pure titanium (Ti) screw implants (3.75 x 10 mm), while the contralateral side received three hydroxyapatite (HA) coated root-form implants (3.3 x 10 mm). Consequently, the coronal 5 mm of each implant was surrounded by a circumferential defect approximately 3 mm wide and 5 mm deep. The three dental implants in each quadrant received either DFDBA (canine source) and an expanded polytetrafluoroethylene membrane (ePTFE), ePTFE membrane alone, or no treatment which served as the control. Clinically, the greatest increase in ridge height and width was seen with DFDBA/ePTFE. Histologically, statistically significant differences in defect osseointegration were seen between treatment groups (P < 0.0001: DFDBA/ePTFE > ePTFE alone > control). HA-coated implants had significantly greater osseointegration within the defect than Ti implants (P < 0.0001). Average trabeculation of newly formed bone in the defect after healing was significantly greater for HA-coated implants than for titanium (P < 0.0001), while the effect on trabeculation between treatments was not significantly different (P = 0.14). Finally, there were significantly less residual allograft particles in defect areas adjacent to HA-coated implants than Ti implants (P = 0.0355). The use of HA-coated implants in large size defects with DFDBA and ePTFE membranes produced significantly more osseointegration histologically than other treatment options and more than Ti implants with the same treatment combinations. The results of this study indicate that, although the implants appeared osseointegrated clinically after 4 months of healing, histologic data suggest that selection of both the implant type and the treatment modality is important in obtaining optimum osseointegration in large size defects.     

Capillarovenous angioma of the maxillary sinus. Apropos of a case with review of the literature

Metabolic side-effects of antihypertensive drugs may increase the risk of coronary heart disease despite an adequate blood pressure reduction. Since combinations of different antihypertensive drugs are often necessary and frequently used, we performed a randomized study comparing the effects of a fixed combination of hydrochlorothiazide and sotalol (group A), or hydrochlorothiazide and captopril (group B) on blood pressure and on lipid and glucose metabolism in 40 men with essential hypertension over 1 year. Significant blood pressure reductions (p < 0.001) were achieved in both treatment groups: from 160/105 to 128/88 mmHg in group A (mean doses: hydrochlorothiazide 33 and sotalol 197 mg) and from 162/106 to 135/89 mmHg in group B (hydrochlorothiazide 33 and captopril 64 mg) after 12 months, respectively. No significant changes in body weight were observed in either treatment group. Triglycerides increased (p < 0.05) in both treatment groups (from 183 to 262 mg/dl in A, and from 160 to 196 mg/dl in B) and HDL cholesterol decreased (p < 0.001 and < 0.05) in both groups (from 45.1 to 35.7 mg/dl in A, and from 49.3 to 46.3 mg/dl in B), whereas LDL cholesterol increased significantly (p < 0.05) only in group A from 153 to 164 mg/dl. No significant changes were observed in total cholesterol nor in lipoprotein(a) concentrations in either treatment group. Fasting plasma glucose and hemoglobin A1 increased significantly (p < 0.05) only in group A after 1 year of treatment (from 91.6 to 98.0 mg/dl, and from 6.3 to 6.9%, respectively). Serum levels of creatinine and potassium decreased, and uric acid increased significantly under either combination. Our data show that the diuretic/beta-blocker combination has adverse effects on lipid and glucose metabolism after long-term therapy. The effects of the diuretic/ACE inhibitor combination on lipid metabolism are less pronounced and there are no adverse effects on glucose metabolism. However, the ACE inhibitor component could not completely counteract the metabolic effects of the diuretic. Both combinations have no effects on Lp(a). We conclude that the combination of hydrochlorothiazide with an ACE inhibitor has a better metabolic profile for the treatment of essential hypertension than the combination with a beta-blocker.     

Ultrastructure of the secretory cells of the submucosal glands in the human maxillary sinus

Tissue samples obtained from the lateral wall of the maxillary sinuses of five patients were examined by light microscopical, histochemical, and ultrastructural techniques. Submucosal glands were tubulo-alveolar mixed glands. The acini consisted of either all serous or all mucous cells, or a mixture of both. Serous granules were stained by toluidine blue, or by hematoxylin and eosin (H and E), but showed little or no reaction with periodic acid-Schiff (PAS) or Alcian blue. Mucous granules were pale in toluidine blue or H and E preparations, and consisted primarly of acid mucosubstances, as demonstrated by their staining reaction with PAS and Alcian blue. At the electron microscope level, the serous granules were either homogeneously dense, or showed a substructure consisting of at least two layers of distincly different electron-opacity. Typical mucous droplets consisted of a fibrillar network dispersed in a translucent matrix. A second secretory product was present in the mucous cells in the form of elongated, membrane-bounded structures containing numerous parallel filaments, which measured about 55 A in diameter. The mucous droplets and the filamentous bodies appear to arise from the opposite faces of the Golgi complex in the mucous cells. The filamentous bodies showed a pronounced tendency to fuse with the mucous droplets. All acini were surrounded by a well-defined myoepithelial layer and contained intercellular nerve terminals.     

含钛中碳钢中钛氧化物析出热力学分析

以含钛中碳钢为研究对象,从热力学的角度分析了含钛中碳钢中钛氧化物析出行为,结果表明:浇注温度为(1535±10)℃且钢中溶解氧含量大于0.003％(质量分数,余同)时,低钛中碳钢中的溶解Ti可与钢中的溶解氧反应生成Ti3O5、Ti2O3,生成TiO2、TiO夹杂的可能性较小;高钛中碳钢中的溶解Ti可与钢中的溶解氧反应生...     

Myoepithelial carcinoma (malignant myoepithelioma): first report of an occurrence in the maxillary sinus

A cDNA clone encoding a Xenopus cysteine string protein (Xcsp) was isolated and sequenced. The deduced primary sequence of Xcsp is very similar to other vertebrate csps with the exception of a cysteine residue that lies outside of the cysteine-string domain. This cysteine residue replaces a serine that is highly conserved among vertebrate csps, and thus may be of functional importance. Xcsp mRNA appears as a 4.6 kb species on Northern analysis, and immunoblot of Xenopus brain membranes reveals a single, 35 kDa Xcsp that can be deacylated, like other csps.     

Adenoid cystic carcinomas of the maxillary sinus with intracranial invasion. Review of the literature, apropos of a case

The aims of this study were to analyze and assess dimensions of the Dental Fear Survey (DFS), which has been developed to measure dental fears and phobias. The present study of 313 dental-phobic individuals analyzed the DFS in a factor analysis using an exploratory (EFA) and a confirmatory (CFA) factor analysis to show dimensions and latent variables. The EFA showed a five-factor structure, with dimensions including items characterizing 'Avoidance of dental care', 'Physiologic arousal during dental treatment', 'Anticipatory anxiety while waiting for dental treatment', 'Fear of the injection needle', and 'Fear of the drill'. The total explained variance of the EFA was 63%. Although statistically significant, the CFA model showed a factor structure with 6 latent variables including a general dental fear factor loading on all 20 items together with the aforementioned 5 factors. In spite of the limitation in sample size and the significant test statistic for this 6-factor structure, the model was interpretable in its dimensionality. In conclusion, these factor analyses have shown a different factor structure of the DFS in this sample of dental-phobic individuals as compared with the dimensions reported from previous research in samples representing nonclinical populations.     

The role of attention in feature detection and conjunction discrimination: an electrophysiological analysis

An electrophysiological probe technique was used to ascertain whether the same attentional mechanisms are employed for both the detection of simple visual features and the discrimination of conjunctions of features. Visual search arrays containing 14 grey items and 2 colored items were presented; one color was designated relevant for each trial block. Subjects were required to report the presence or absence of the relevant color (feature detection condition) or the shape of the relevantly-colored item (conjunction discrimination condition). Shortly after the onset of the search array, a task-irrelevant probe stimulus was flashed at the location of the relevant or irrelevant color and the event-related potential (ERP) produced by this stimulus was used to assess sensory processing at the probed location. Probes presented at the location of the relevant color were found to elicit enhanced ERP components and probes presented on the opposite side of the display from the relevant color elicited suppressed components. These effects were observed in both the detection and discrimination conditions, indicating that spatially restricted attentional processes are used for both the detection of simple features and the discrimination of conjunctions. However, one ERP component (the PI wave) exhibited these effects in the discrimination condition but not in the detection condition, indicating that conjunction discrimination utilizes additional attentional processes beyond those required for feature detection.