Durability of FTLA treatment as a medicament for dentin hypersensitivity--abrasion resistance and profiles of fluoride release

The purpose of this study was to evaluate the durability of tubules occluded with FTLA treatment by toothbrush abrasion test on the applied surface and by measuring fluoride release from the FTLA components. Dentin specimens with simulated hypersensitive surfaces were treated with APF containing tannic acid. After which, the specimens received lanthanum-chloride-with-powdered-fluoroapatite-glass-ceramics treatment. The specimens were subjected to toothbrush abrasion test up to 6,000 strokes. SEM observation revealed that dentinal tubules of the FTLA treated specimens were completely occluded with fine deposits even after toothbrush abrasion of 6,000 strokes. EPMA analysis revealed that fluoride, lanthanum, and aluminum were the main FTLA components on the dentin surface after 6,000-stroke abrasion. To measure fluoride release from the FTLA components, a slurry was enclosed in a cellulose tube and suspended in deionized water at 37 degrees C. After fluoride was dialyzed against deionized water, a high concentration of fluoride was found to be released from FTLA the components, indicating FTLA treatment's prominent durability. These results suggested that FTLA treatment has a superior resistance against toothbrush abrasion and a high fluoride-releasing performance. These characteristics lend much weight to showing that the FTLA method is an effective and durable medicament for dentin hypersensitivity.     

Prevention of vocal fold scarring by topical injection of hepatocyte growth factor in a rabbit model

OBJECTIVES/HYPOTHESIS: Vocal fold scarring disrupts the layer structure of the vocal fold lamina propria that is essential for optimal mucosal vibration. Prevention of vocal fold scarring remains challenging. Hepatocyte growth factor (HGF) has strong antifibrotic activity. The authors' previous studies have found that HGF stimulates hyaluronic acid production and suppresses collagen production from vocal fold fibroblasts, suggesting that HGF has therapeutic potential in prevention of vocal fold scarring. The present study aimed to demonstrate the effects of HGF on vocal fold scarring in an in vivo rabbit model. STUDY DESIGN: Animal experiment. METHODS: The vocal fold mucosa was stripped unilaterally in 20 rabbits, then HGF or saline (sham-treated group) was immediately injected into the injured site. At 6 months after the procedure, histological, rheological, and physiological examinations of vibratory behavior were completed. RESULTS: Histological examination revealed excessive collagen deposition and disorganized elastin in the sham-treated group, whereas the HGF-treated group presented with better wound healing exhibiting less collagen deposition. Contraction of the injured vocal folds observed in the sham-treated group did not occur in the HGF-treated group. Rheological data indicated that the HGF-treated vocal folds were less stiff and viscous compared with the sham-treated group. Mucosal vibration of HGF-treated vocal folds appeared much better than the sham-treated group in terms of phonation threshold pressure, vocal efficiency, mucosal wave amplitude, and glottal closure. CONCLUSION: Hepatocyte growth factor proved to be useful in preventing vocal fold scarring and maintaining viscoelastic shear properties of the vocal fold.     

Intrapartum fetal heart rate monitoring in cases of cytomegalovirus infection

OBJECTIVE: Several studies have shown that abnormal intrapartum fetal heart rate patterns are the results from pre-existing fetal brain damage. We evaluated intrapartum fetal heart rate pattern of cytomegalovirus-infected fetuses and correlated the patterns with neurologic outcomes. STUDY DESIGN: Between 1991 and 2001, there were 20 cytomegalovirus-infected fetuses. We selected 40 fetuses as control subjects that were matched for gestational age and birth weight. Fetal heart rate was interpreted according to the guidelines of the National Institute for Child and Human Development. The incidence of abnormal fetal heart rate pattern and umbilical blood gases were compared between both groups. We also investigated the factors that contributed to abnormal fetal heart rate pattern in the cytomegalovirus group. RESULTS: Nonreassuring fetal heart rate patterns (prolonged deceleration and recurrent late deceleration) were observed in 8 of 20 fetuses (prolonged deceleration, 7 fetuses; recurrent late deceleration, 1 fetus) in the cytomegalovirus group and in 3 of 41 fetuses (prolonged deceleration, 1 fetus; recurrent late deceleration, 2 fetuses) in the control group (P<.05, Fisher test). Baseline fetal heart rate variability was minimal in 4 of the 7 prolonged deceleration cases in the cytomegalovirus group. Umbilical pH <7.1 was found for 1 fetus in the cytomegalovirus group. The average umbilical arterial pH values were similar in both the groups. In the cytomegalovirus group, there were no differences in the incidence of contributing factors between 8 fetuses with abnormal fetal heart rate pattern (prolonged deceleration and recurrent late deceleration) and 8 fetuses with no change. There were 3 fetuses with cerebral palsy: 2 fetuses in the no change group and 1 fetus in the prolonged deceleration group. Antigenemia was positive exclusively in 4 cases with abnormal fetal heart rate pattern (P<.05). CONCLUSION: Cytomegalovirus-infected fetuses are more likely to show abnormal intrapartum fetal heart rate patterns than low-risk control fetuses, which suggests that the perinatal detection of cytomegalovirus is necessary to distinguish hypoxic-ischemic encephalopathy.     

Successful pregnancy following conservative treatment of massive ascites associated with acute <Emphasis Type="Italic">Chlamydia trachomatis</Emphasis> peritonitis

It is well known that Chlamydia trachomatis causes acute and chronic pelvic inflammatory disease including salpingitis. We describe a case of successful pregnancy following conservative treatment of massive ascites associated with acute Chlamydia trachomatis peritonitis. In this present case, we conservatively treated a woman with acute chlamydial salpingitis accompanied with marked ascites and an adnexal mass that simulated a malignant neoplasm. Elevated CA125 and CA19-9 also suggested a malignancy at the time of diagnosis, however following treatment they decreased to below the cut-off value, and were useful in identifying the efficacy of medical treatment. The patient subsequently became pregnant after infertility treatment and underwent a normal vaginal delivery. We conclude that the possibility of Chlamydia trachomatis peritonitis should be considered when a patient presents with ascites and an adnexal mass in sexually active women. (Reprod Med Biol 2004; 3 : 217–221)     

Venous-drainage-guided selective hepatectomy: a novel approach to liver surgery

Selective hepatectomy under the guidance of hepatic venous drainage has not yet been developed because hepatic venous occlusion alone produces no visible congested area. Now that this area can be identified by simultaneous occlusion of the hepatic vein and artery, venous-drainage-guided selective hepatectomy is considered feasible. Because the congested area becomes dysfunctional or atrophic due to the absence of portal blood supply, it can be regarded as a first candidate for preventive resection in livers that may bear latent tumors. We report here a novel approach to selective hepatectomy. Segment 4 hepatectomy and ventral hemisectorectomy of segments 5+8, with middle hepatic vein resection, was undertaken in a patient with hepatocellular carcinoma. After hepatic dissection between segments 2+3 and 4, the root of the middle hepatic vein was isolated. Test clamping of the middle hepatic vein and proper hepatic artery demonstrated a discolored area. Hepatic dissection was performed along the discolored border towards the hepatic hilum, exposing the right anterior portal pedicle with division of the ventral branches. The middle hepatic vein was finally divided. Selective hepatectomy was successfully performed without transfusion or complications. Venous-drainage-guided selective hepatectomy is feasible with acceptable perioperative results.     

Halothane and propofol modulation of gamma-aminobutyric acidA receptor single-channel currents

Halothane and propofol enhance the activity of the gamma-aminobutyric acid (GABA) system, which is one of the most important systems in the mechanism of anesthesia. To determine whether halothane and propofol enhance GABAergic responses by the same mechanism, we performed single-channel patch-clamp experiments with rat cortical neurons in primary culture. Each of the open-time and closed-time distributions of GABA(A) receptor single channels was expressed by a sum of fast and slow time constants. Neither halothane nor propofol changed the single-channel conductance. Halothane increased the probability of the channel being open via a prolongation of the slow phase of open time, whereas propofol increased the channel open probability via a shortening of the slow phase of closed time. Thus, although both halothane and propofol augmented the channel open probability, thereby causing an increase in charge transfer during inhibitory transmitter action, they acted by different mechanisms.     

Arterioportal shunting as an alternative to microvascular reconstruction after hepatic artery resection

BACKGROUND: Portal vein and hepatic artery resection and reconstruction may be required in radical surgery for biliary cancer. Microvascular reconstruction requires special equipment and training, and may be difficult to accomplish when the arterial stump is small, when there are multiple vessels or when the stump lies deep within the wound. This study examined the feasibility and safety of arterioportal shunting as an alternative to arterial reconstruction. METHODS: Over 30 months, ten patients with biliary cancer (six bile duct and four gallbladder carcinomas) underwent radical surgery with en bloc resection of the hepatic artery and end-to-side arterioportal reconstruction between the common hepatic or gastroduodenal artery and the portal trunk. RESULTS: No patient died. Complications included bile leakage in two patients and liver abscess in one. Routine angiography performed 1 month after surgery revealed shunt occlusion in three patients. Once the existence of hepatopetal arterial collaterals had been confirmed in the remaining patients, the shunt was occluded by coil embolization. CONCLUSION: Arterioportal shunting appears to be a safe alternative to microvascular reconstruction after hepatic artery resection. However, the safety of the procedure and its potential to increase the cure rate require further assessment in a larger series with a longer follow-up.     

Immunolocalization of vascular endothelial growth factor during heterotopic bone formation induced from grafted periosteum

Vessel invasion is an important step in cartilage replacement that leads to bone formation, and vascular endothelial growth factor (VEGF) has been implicated as a key player in this process. Although grafted periosteum undergoes endochondral ossification, little is known about the role of VEGF in this process. In the current study the authors investigated by immunohistochemical, histochemical, and ultrastructural techniques the localization of VEGF during bone formation in periosteal grafts. At day 14 after grafting the tibias of Japanese white rabbits, periosteal cells in the grafted tissue had differentiated into chondrocytes to form cartilage. Some chondrocytes were immunopositive for VEGF expression, and subsequent vessel invasion occurred predominantly in these VEGF-positive areas. At day 45, the cartilage invaded by blood vessels had been replaced by newly formed bone. These findings suggest that VEGF is associated with the process of blood vessel invasion into cartilage before bone replacement in endochondral ossification from grafted periosteum.     

Development of a novel polyimide hollow-fiber oxygenator

We have developed a membrane oxygenator using a novel asymmetric polyimide hollow fiber. The hollow fibers are prepared using a dry/wet phase-inversion process. The gas transfer rates of O(2) and CO(2) through the hollow fibers are investigated in gas-gas and gas-liquid systems. The polyimide hollow fiber has an asymmetric structure characterized by the presence of macrovoids, and the outer diameter of the hollow fiber is 330 microm. It is found that the polyimide hollow-fiber oxygenator can enhance the gas transfer rates of O(2) and CO(2), and that the hollow fiber provides excellent blood compatibility in vitro and in vivo.