ORAOV1-A correlates with poor differentiation in oral cancer

Oral cancer overexpressed 1 (ORAOV1) is a crucial oncogene in oral squamous cell carcinoma (OSCC). In this study, we have identified a novel splice variant of ORAOV1, designated as ORAOV1-A. To study the potential role of ORAOV1-A in OSCC, we tested its expression in 7 OSCC cell lines, as well as in 19 normal oral tissue samples and 47 OSCC tissue samples. The expression of ORAOV1-A was detectable in 6 out of 7 OSCC cell lines tested. In OSCC tissue samples, the expression frequency of ORAOV1-A (51.1%) was much higher than that in normal samples (10.5%). Notably, an inverse correlation was found between the expression frequency of ORAOV1-A and the degree of differentiation in OSCC (P = 0.0017). In conclusion, our results suggested that ORAOV1-A may play a functional role in the tumorigenesis of OSCC, and ORAOV1-A expression may serve as an adjunctive prognostic indicator for persons with OSCC.

Discoloration characteristics of 3 major muscles from cattle during cold storage

Discoloration characteristics of 3 major muscles (LD, Longissimus dorsi; PM, Psoas major; SM, Semimemebranosus) from Korean native cattle (Hanwoo) were monitored during 7 d of cold storage at 4 degrees C. The muscles were obtained from 12 Hanwoo carcasses at 24 h postmortem. Meat color (CIE L*, a*, b*), myoglobin (Mb) concentration, chemical form, metmyoglobin (MetMb) reducing ability (MRA), mitochondria concentration, and thiobarbituric acid reactive substance (TBARS) were measured at 1, 3, 5, and 7 d of storage. Although there were no significant differences in CIE a* and b*-values between the 3 muscles at day 1, the values of PM muscle were significantly (P < 0.05) lower than those of LD and SM muscles at day 5 and 7. PM muscle showed a rapid decrease in the oxymyoglobin (OxyMb) and an increase in MetMb, which resulted in a significantly (P < 0.05) higher percentage of MetMb in PM muscle compared to LD and SM muscles. Also, the Mb and mitochondria concentration of PM muscle was significantly (P < 0.05) higher than those of LD and SM muscles. However, there were no significant differences in MRA, pH, or TBARS between the 3 muscles during 7 d of cold storage. It was concluded that rapid discoloration (that is, MetMb accumulation) in PM muscle of Hanwoo could be due to its higher contents of Mb and mitochondria.

Clinical survey of sedation and analgesia procedures in intensive care units

BACKGROUND

The proper use of sedation and analgesia in the intensive care unit (ICU) minimizes its physical and psychological impact. Otherwise, patients can suffer from recall, nightmares, and depression after discharge. We investigated the sedatives, analgesics, and muscle relaxants used in the ICU.

METHODS

We visited 79 ICUs in 52 training hospitals and noted the use of sedatives, analgesics, and muscle relaxants from July, 2007, to December, 2007, using a 5-item questionnaire with 57 sub-questions. The survey evaluated the ICU system administration of analgesics and muscle relaxants.

RESULTS

Most ICU management is done by the anesthesiology department (55%). Most have resident doctors (63.3%) and an ICU committee (60.8%) in charge of the ICU, as well as a special ICU chart (88.6%) and scoring system (65.8%). Most hospitals have a consulting system (94.9%). The standard ICU analgesics are fentanyl (65.8%), NSAIDs (53.2%), and morphine (48.1%).

CONCLUSIONS

Adequate sedation is difficult to achieve in the ICU, but is important for patient comfort and to reduce ICU stay duration. Awareness of patient status and appropriate drug/protocol use are therefore important.

Effect of chilling temperature of carcass on breast meat quality of duck

An experiment was carried out to investigate whether variations in chill water temperature affect muscle shortening and meat quality in duck breast. Three chill water temperatures were applied to duck carcasses at 20 min postmortem for 30 min, including in ice water at 0 degrees C, in cold water at 10 degrees C, and in water at 20 degrees C. Results revealed that carcass temperatures were different (P < 0.05) at 50 and 120 min of postmortem with lower temperatures at the 0 degrees C treatment (P < 0.05). The pH over the first 24 h postmortem was not different (P > 0.05) among treatments, with the exception of 50 min postmortem. The pH of breast meat in the 0 degrees C treatment was higher (P < 0.05) than that of 20 degrees C treatment at 50 min postmortem (just after chilling). No other differences (P > 0.05) in pH existed among treatments. Drip loss, cooking loss, and moisture content were not different for breast meat samples that were chilled at different temperatures. Differences (P < 0.05) were found in CIE (L, a, and b) color values. Lightness (L) increased, whereas redness (a) decreased as the chill water temperature increased. Lower yellowness (b) was found in the breast meat samples at the 10 degrees C chill water temperature. However, shear force, sarcomere length, and protein solubility were not different (P > 0.05) among the breast meat samples chilled at different chill water temperatures. It may be concluded that chilling duck carcasses at different temperature ranges from 0 to 20 degrees C did not influence muscle shortening or meat quality, except in regard to breast meat color.

Targeted RNA interference of phosphatidylinositol 3-kinase p110-beta induces apoptosis and proliferation arrest in endometrial carcinoma cells

Phosphatidylinositol 3-kinase (PI3K) signalling plays a pivotal role in intracellular signal transduction pathways involved in cell growth, cellular transformation, and tumourigenesis. PI3K is overexpressed in many human cancers, including endometrial carcinomas, one of the most common female genital tract malignancies. Here, we used small interfering RNA (siRNA) targeted to PI3K p110-beta to determine whether inhibition of the beta isoform could be a potential therapeutic target for endometrial carcinoma. In this study, treatment of HEC-1B endometrial cancer cells with PI3K p110-beta-specific siRNA resulted in increased apoptosis and decreased tumour cell proliferation. Depletion of PI3K p110-beta decreased the protein levels of AKT1, AKT2, pAKT, and mTOR-downstream targets of PI3K. Knock-down of PI3K p110-beta by siRNA also induced decreased expression of cyclin E and Bcl-2, suggesting that PI3K p110-beta stimulates tumour growth, at least in part by regulating cyclin E and Bcl-2. Thus, our results indicate that siRNA-mediated gene silencing of PI3K p110-beta may be a useful therapeutic strategy for endometrial cancers overexpressing PI3K p110-beta.

The relationship of physiological maturity and marbling judged according to Korean grading system to meat quality traits of Hanwoo beef females

Fifty seven carcasses from Hanwoo beef females were randomly selected by official meat graders and were sorted into three levels of maturity and marbling. Carcass data was collected for back fat thickness, longissimus area, carcass weight, meat colour, fat colour, marbling score, yield and quality grades. Mature carcasses had more yellow fat, coarser texture, a larger longissimus muscle area and lower quality grades and marbling scores (P<0.05). Carcasses with a higher marbling score had thicker fat and a higher quality grade. Carcasses with low marbling had a higher yield grade and a coarser texture (P<0.05). Higher marbling scores corresponded with lower cook and drip loss values for longissimus steaks. As the maturity of carcass was increased, the redness and lightness of meat and the yellowness of fat all tended to increase. Tenderness, flavour and overall acceptability scores for the older maturity group were lower than for younger and intermediate groups. Marbling was significantly (P<0.01) correlated with quality grade, crude fat content, cook and drip losses, and Warner-Bratzler shear force. The maturity level was also significantly (P<0.01) correlated with quality grade, fat colour, texture score, number of calves produced and milk teeth, meat redness and yellowness, fat yellowness, and Warner-Bratzler shear force. Results indicate that a low marbling group and older maturity group based on Korean grading system could negatively influence carcass traits and beef qualities of Hanwoo beef female.

The effect of phenytoin on rocuronium-induced neuromuscular block in the rat phrenic nerve-hemidiaphragm preparation

Anticonvulsant therapy alters the action of nondepolarizing muscle relaxants. We determined the effects of acute and chronic administration of phenytoin on rocuronium-induced neuromuscular block using the rat phrenic nerve-hemidiaphragm preparation. Rats were divided into 3 groups: a saline control group (n = 10), an acute phenytoin-treated group (n = 30), and a chronic phenytoin-pretreated group (n = 30). Phrenic nerve-hemidiaphragm was dissected, mounted in a bath containing oxygenated Krebs solution, and the nerve was stimulated at supramaximal intensity. Single twitch responses were recorded by physiogram. In the acute phenytoin-treated group, acute effects of phenytoin were determined based on the phenytoin concentration of 1, 10, or 100 microg/mL in the bath. The chronic effects of phenytoin were determined using phrenic nerve-diaphragms from rats pretreated with phenytoin (50 mg/kg/d) for 1, 7, or 28 days. In rats with phenytoin 100 microg/mL in the bath, all concentrations of rocuronium produced twitch depression significantly different from those of other groups (P < 0.05), and the concentration-response curve shifted to the left. In rats with phenytoin 10 microg/mL in the bath, the effective concentrations for 50%, 90%, and 95% twitch depression values were significantly different from those of the control group (P < 0.05). In chronically (28 days) phenytoin-pretreated rats, the concentration-response curve significantly shifted to the right (P < 0.05). These findings show that acute administration of phenytoin augmented the neuromuscular blocking effects of rocuronium, whereas chronic phenytoin treatment causes resistance to the neuromuscular blocking effects of rocuronium in target organs.

High-dose glucose-insulin-potassium treatment reduces myocardial apoptosis in patients with acute myocardial infarction

BACKGROUND

Several clinical trials have suggested that a metabolic cocktail of glucose-insulin-potassium (GIK) decreases mortality rates in patients with acute myocardial infarction (AMI). It has also been reported that Fas-mediated apoptosis plays an important role in ischaemic/reperfusion injury in the rat model. This study was designed to evaluate the interaction of ischaemic/reperfusion and reperfusion therapy coadministered with high-dose GIK treatment on soluble Fas/APO-1 (sFas) and Fas ligand (sFasL) plasma concentration in patients with AMI.

MATERIALS AND METHODS

Seventy-four patients presenting with AMI who underwent reperfusion therapy were randomized into a GIK group (n = 35) receiving high-dose GIK for 24 h or a vehicle group (n = 39). Thirty-four control subjects were also enrolled in the present study. Strepavidin-biotin ELISA was used to determine the soluble sFas and sFasL plasma concentration at baseline, 24 h (h), 3 day (d), 7 d and 14 d.

RESULTS

Soluble Fas and sFas-L serum concentrations ([sFas] and [sFas-L]) of patients with AMI were significantly elevated at baseline as compared with normal controls (NCs; P < 0.01 vs. NC). The sFas in the GIK and vehicle groups markedly decreased 24 h after the GIK infusion (10.7-->5.9 ng mL(-1) and 9.7-->6.5 ng mL(-1); P < 0.01 vs. baseline) and then increased during the 3-7-d period (5.9-->12.1 ng mL(-1) and 6.5-->11.1 ng mL(-1); P < 0.01 vs. 24 h). The GIK group demonstrated reduced sFas (12.1-->5.9 ng mL(-1)) at 14 d (P < 0.01 vs. 7 d), with no concomitant changes in the vehicle group. The sFas-L in the GIK and vehicle groups was not significant different during the 14-d period.

CONCLUSIONS

These results indicate that the sFas and sFasL in patients with AMI increased significantly compared with NC. Owing to the cardioprotective effects reported here and by others, a high-dose GIK infusion co-administered with the timely re-establishment of nutritive perfusion should be strongly considered as a treatment of choice for AMI. Additionally, sFas may be a valuable marker of the physiological response to ischaemic/reperfusion injury and reperfusion associated with high-dose GIK treatment.

Periocular injection of an adenoviral vector encoding pigment epithelium-derived factor inhibits choroidal neovascularization

Gene transfer provides an exciting new approach for the treatment of retinal and choroidal diseases. Two areas of concern are the potential for vector-related toxicity and uncertainties associated with prolonged transgene expression. One way to address these concerns for transfer of genes encoding secreted proteins is to transduce cells on the outside of the eye, provided the gene product can gain access to the eye and have the desired effect. In this study, we investigated the feasibility of this approach. Periocular injection of an adenoviral vector encoding beta-galactosidase (AdLacZ.10) resulted in LacZ-stained cells throughout the orbit and around the eye. Compared to periocular injection of 5 x 10(9) particles of control vector, periocular injection of 5 x 10(9) or 1 x 10(9) particles of an adenoviral vector expressing pigment epithelium-derived factor (PEDF) regulated by a CMV promoter (AdPEDF.11) resulted in significantly elevated intraocular levels of PEDF and suppression of choroidal neovascularization. Periocularly injected recombinant PEDF was also found to diffuse through the sclera into the eye. Although similar experiments are needed in an animal with a human-sized eye, these data suggest that periocular gene transfer deserves consideration for the treatment of choroidal diseases.

Cord blood mononuclear cell cytokine responses in relation to maternal house dust mite allergen exposure

BACKGROUND

Cord blood mononuclear cells have demonstrated specific immune responses to environmental allergens.

OBJECTIVE

To establish whether the nature of this response is related to the level of maternal antenatal exposure to house dust mite (HDM) allergen and, hence, whether antenatal allergen avoidance may have a role in the prevention of allergic sensitization in children.

METHODS

Children with a family history of asthma were recruited antenatally as subjects in a randomised controlled trial: the Childhood Asthma Prevention Study. HDM allergen (Der p 1) concentrations were measured in dust collected from the maternal bed at 36 weeks gestation. Cord blood mononuclear cells were stimulated in culture, separately, with phytohaemaglutinin (PHA) and HDM extract. Cytokine IL-4, IL-5, IL-10 and IFN-gamma concentrations in supernatant were measured by ELISA. mRNA signals for these cytokines were measured using RT-PCR.

RESULTS

The median concentration of HDM allergen was 18.4 microg/g (interquartile range 7.3-35.3 microg/g). Median concentrations of IL-4, IL-5, IL-10 and IFN-gamma, after PHA stimulation were 4, 19, 401 and 1781 pg/mL, respectively. After HDM allergen stimulation the median concentrations were 0, 0, 20 and 14 pg/mL, respectively. The distribution of mRNA cytokine signals was similar. Neither cytokine protein concentrations nor cytokine mRNA signal levels were correlated with the concentration of HDM allergen in the mothers' beds at 36 weeks gestation.

CONCLUSION

These findings do not support the view that the prevention of allergic disease in children requires the institution of HDM avoidance interventions during pregnancy.

Effect of poling conditions on growth of calcium phosphate crystal in ferroelectric BaTiO3 ceramics

Recently, ceramic materials have been given a lot of attention as candidates for implant materials, since they possess biologically favorable characteristics for osseointegration. Among them, BaTiO3 (BTO) ceramics are ferroelectric and piezoelectric after poling treatments. However, little or no information is available on the poling condition of BTO and their effect on calcium phosphate (CaP) formation. In this study, the effect of poling conditions on the formation of CaP layer was investigated. It was observed from this study that CaP was formed on negatively charged BTO surfaces. An increase in Ca/P ratio to 1.67 was observed when the poling temperature was increased above the Curie temperature. On positively charged BTO, no CaP layer was observed.

The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases

PURPOSE

To report on the use of the laryngeal mask airway (LMA) for elective Cesarean section in 1067 consecutive ASA I-II patients preferring general anesthesia.

METHODS

Patients were excluded if they had pharyngeal reflux, a pre-pregnancy body mass index >30, or had a known/predicted difficult airway. Patients were fasted for six hours and given ranitidine/sodium citrate. A rapid sequence induction was performed with thiopentone and suxamethonium. The LMA was inserted by experienced users. Anesthesia was maintained with N(2)O and 50% O(2) and a volatile agent. Cricoid pressure was maintained until delivery, but was relaxed if insertion/ventilation was difficult. Patients were intubated if an effective airway was not obtained within 90 sec, or SpO(2) <94%, or end-tidal CO(2) >45 mmHg. Postdelivery, vecuronium and fentanyl were administered.

RESULTS

An effective airway was obtained in 1060 (99%) patients, 1051 (98%) at the first attempt and nine (1%) at the second or third attempt. Air leakage or partial airway obstruction occurred in 22 (21%) patients, and seven (0.7%) patients required intubation. There were no episodes of hypoxia (SpO(2) <90%), aspiration, regurgitation, laryngospasm, bronchospasm or gastric insufflation. Surgical conditions were satisfactory and all APGAR scores were >/=7 after five minutes.

CONCLUSION

We conclude that the LMA is effective and probably safe for elective Cesarean section in healthy, selected patients when managed by experienced LMA users.

Inactivation of the murine pyruvate dehydrogenase (Pdha1) gene and its effect on early embryonic development

A deficiency of pyruvate dehydrogenase complex (PDC) in humans results in lactic acidosis and neurological dysfunction that frequently results in death during infancy. Using gene targeting technology, a silent mutation was introduced into the murine X-linked Pdha1 gene that encodes the alpha subunit of the pyruvate dehydrogenase or E1 component of the complex. Two loxP sequences were introduced into intronic sequences flanking exon 8 to generate the Pdha1(flox8) allele. In vitro studies in embryonic stem cells demonstrated that deletion of exon 8 ablated PDC activity. Homozygous Pdha1(flox8) females were bred with male mice carrying a wild-type Pdha1 allele and a transgene that ubiquitously expresses the Cre recombinase to produce progeny with a deletion in exon 8, Pdha1(Deltaex8). The majority of progeny were found to be mosaic with the presence of both the flox and deleted alleles, and there were no apparent phenotypic effects associated with the null allele. The mosaic mice were interbred to increase the degree of mosaicism for the Pdha1(Deltaex8) allele in the subsequent generation, resulting in a significantly smaller litter size (54% reduction). Embryos carrying predominantly the Pdha1(Deltaex8) allele were found to be globally delayed in development by 9.5 days postcoitus, with resorption occurring over the following several days. These findings demonstrate an essential role for oxidative metabolism of glucose during the early postimplantation period of prenatal development.

Clinical characteristics of constrictive pericarditis diagnosed by echo-Doppler technique in Korea

A retrospective analysis of clinical data of 71 patients with constrictive pericarditis (CP) diagnosed by echo-Doppler technique (mean age, 49+/-17) was done. In 27 patients (38%), the etiology was unknown, and the three most frequent identifiable causes were tuberculosis (23/71, 32%), cardiac surgery (8/71, 11%), and mediastinal irradiation (6/71, 9%). Pericardiectomy was performed in 35 patients (49%) with a surgical mortality of 6% (2/35), and 11 patients (15%, 11/ 71) showed complete resolution of constrictive physiology with medical treatment. Patients with transient CP were characterized by absence of pericardial calcification, shorter symptom duration, and higher incidence of fever, weight loss, and tuberculosis. The 5-yr survival rates of patients with transient CP and those undergoing pericardiectomy were 100% and 85+/-6%, respectively, which were significantly higher than that of patients without undergoing pericardiectomy (33+/-17%, p=0.0083). Mediastinal irradiation, higher functional class, low voltage in ECG, low serum albumin, and old age were the independent variables associated with a higher mortality. Tuberculosis is still the most important etiology of CP in Korea, and not infrequently, it may cause transient CP. Early diagnosis and decision-making using follow-up echocardiography are crucial to improve the prognosis of patients with CP.

Human dihydrolipoamide dehydrogenase gene transcription is mediated by cAMP-response element-like site and TACGAC direct repeat

Dihydrolipoamide dehydrogenase is a common component of four multienzyme complexes which are involved in oxidation of carbohydrates, lipids and amino acids. To better understand the regulation of human DLD gene expression, we have analyzed the proximal promoter region of this gene. DNase I footprinting analysis of the promoter region (-322 to +47 bp) revealed four major protein-binding domains (termed P1-P4). Nested deletions and site-specific mutations of approximately 100 bp proximal promoter region identified two elements, TACGAC direct repeat sequence and cAMP-response element (CRE)-like site, which are localized in the P2 and P1 domains, respectively, and mediate basal transcription of the DLD gene. Electrophoretic mobility supershift assays showed that the CRE-like site is associated with CRE binding protein. Interestingly, when DLD promoter constructs (-1.8 kb to +47 bp and -78 to +47 bp) fused with the chloramphenicol acetyltransferase (CAT) reporter gene were transiently transfected into human HepG2 cells either in the presence or absence of 0.5 mM 8-Br-cAMP, the levels of CAT expression remained unaffected. In addition, endogenous DLD mRNA levels in HepG2 cells also remained unaffected by treatment with 0.5 mM 8-Br-cAMP. These results indicate that the CRE binding protein is essential for basal transcription of the human DLD promoter, but does not confer cAMP-dependent gene regulation.

Pigment epithelium-derived factor inhibits retinal and choroidal neovascularization

In this study, we investigated whether overexpression of pigment epithelium-derived factor (PEDF) by gene transfer can inhibit neovascularization by testing its effect in three different models of ocular neovascularization. Intravitreous injection of an adenoviral vector encoding PEDF resulted in expression of PEDF mRNA in the eye measured by RT-PCR and increased immunohistochemical staining for PEDF protein throughout the retina. In mice with laser-induced rupture of Bruch's membrane, choroidal neovascularization was significantly reduced after intravitreous injection of PEDF vector compared to injection of null vector or no injection. Subretinal injection of the PEDF vector resulted in prominent staining for PEDF in retinal pigmented epithelial cells and strong inhibition of choroidal neovascularization. In two models of retinal neovascularization (transgenic mice with increased expression of vascular endothelial growth factor (VEGF) in photoreceptors and mice with oxygen-induced ischemic retinopathy), intravitreous injection of null vector resulted in decreased neovascularization compared to no injection, but intravitreous injection of PEDF vector resulted in further inhibition of neovascularization that was statistically significant. These data suggest that sustained increased intraocular expression of PEDF by gene therapy might provide a promising approach for treatment of ocular neovascularization.

Determinants and prognostic implications of terminal QRS complex distortion in patients treated with primary angioplasty for acute myocardial infarction

Terminal QRS complex distortion on admission has an impact on a patient's prognosis after primary angioplasty for acute myocardial infarction (AMI). We evaluated the determinants and prognostic significance of terminal QRS complex distortion in 153 consecutive patients with AMI after primary angioplasty. The study population was divided into 2 groups according to the presence (group I, n = 41) or absence (group II, n = 112) of terminal QRS complex distortion. The primary end points were the occurrence, within 6 weeks after AMI, of death, nonfatal reinfarction, or congestive heart failure. Baseline characteristics were similar between the 2 groups. However, patients in group I had higher peak levels of serum creatine kinase than those in group II (5,100 +/- 3,100 vs 3,000 +/- 1,800 U/L, respectively, p <0.01). The rate of angiographic no-reflow (Thrombolysis In Myocardial Infarction flow grade < or =2) was 31.7% in group I and 10.7% in group II (p <0.01). The predischarge left ventricular ejection fraction was 45.0 +/- 12.0% in group I and 54.0 +/- 8.0% in group II (p <0.01). Multivariate analysis identified the pressure-derived fractional collateral flow index and the culprit lesion in the left anterior descending coronary artery as independent determinants of the terminal QRS complex distortion. No patients died during 6 weeks of follow-up. The 2 groups were similar for life-threatening arrhythmia or reinfarction. However, there were more patients in group I than in group II with congestive heart failure (26.8% vs 5.4%, respectively, p <0.01) or who reached the primary end points (29.3% vs 5.4%, respectively, p <0.01). In conclusion, terminal QRS complex distortion on admission is associated with poor clinical outcome after primary angioplasty for AMI, and collateral flow may have a major influence on terminal QRS complex distortion during AMI.

The effect of thermal change on various dowel-and-core restorative materials

STATEMENT OF PROBLEM

Severe thermal stresses caused by food-induced temperature changes may result in dowel-and-core failure.

PURPOSE

This study investigated the influence of thermal stresses on various combinations of dowel-and-core materials of a restored endodontically treated incisor.

MATERIAL AND METHODS

A 2-dimensional finite element model was constructed in a labiolingual cross-sectional view of a maxillary central incisor, a dowel, a core, and the supporting tissues to investigate thermal stress distribution. Four combinations of dowel-and-core materials were used: (1) gold/gold, (2) stainless steel/resin composite, (3) stainless steel/amalgam, and (4) carbon fiber-reinforced composite/resin composite. For thermal analysis, a cold irritant (0 degrees C) was applied on the outer surface of a metal-ceramic crown for 7 seconds.

RESULTS

The metal dowel and core generated lower thermal stresses in the restorations and dentin than the nonmetallic dowel and cores.

CONCLUSION

Stress level is closely related to the degree of thermal gradient. The nonmetallic dowel and cores generated greater thermal stresses than metal dowel and cores.

Prognostic significance of cerebral metabolic abnormalities in patients with congestive heart failure

BACKGROUND

Cerebral metabolic abnormalities were proposed as a potential marker of disease severity in congestive heart failure (CHF), but their prognostic significance remains uncertain.

METHODS AND RESULTS

We investigated the prognostic value of cerebral metabolic abnormalities in 130 consecutive patients with advanced CHF (100 men aged 42.6+/-11.9 years; left ventricular ejection fraction, 22.2+/-6.2%). Proton magnetic resonance spectroscopy data were obtained from localized regions ( approximately 8 mL) of the occipital gray matter and the parietal white matter. The primary end point was the occurrence of death after the proton magnetic resonance spectroscopy. During follow-up (18.5+/-14.4 months), 21 patients died and 15 underwent urgent heart transplantation. In the Cox proportional model, occipital metabolites (N-acetylaspartate, creatine, choline, and myoinositol), parietal N-acetylaspartate level, and the duration of CHF symptoms (>12 months) were validated as univariate predictors of death. In multivariate Cox analyses, however, the occipital N-acetylaspartate level was an independent predictor of death (hazard ratio, 0.52; 95% CI, 0.41 to 0.67; P<0.001). An analysis with respect to the combined end point of death or urgent transplantation showed similar results. The best cutoff value (9.0 mmol/kg) for occipital N-acetylaspartate level had 75% sensitivity and 67% specificity to predict mortality.

CONCLUSIONS

The occipital N-acetylaspartate level is a powerful and independent predictor of CHF mortality, suggesting that cerebral metabolic abnormalities may be used as a new prognostic marker in the assessment of patients with CHF.

The effects of dowel design and load direction on dowel-and-core restorations

STATEMENT OF PROBLEM

Complications such as loosening of the dowel and core or fracture of the remaining tooth root can be influenced by many factors, including the amount of remaining dentin, direction of the occlusal load, and design of the dowel. Most stress analyses of dowel and cores were conducted without including all aspects of the restorations and supporting structures.

PURPOSE

The purpose of this study was to investigate the influence of occlusal stresses on various dowel designs in a restored, endodontically treated maxillary incisor by using a 2-dimensional finite element analysis model.

MATERIAL AND METHODS

A 2-dimensional finite element model was constructed in a labiolingual cross-sectional view of a maxillary central incisor, a dowel, a core, and the supporting tissues to investigate stresses in various dowel designs. As a control, a metal-ceramic crown on an endodontically treated tooth without a dowel and core was modeled. A 10-kg force was applied as follows: (1) in a vertical load on the incisal edge, (2) in a horizontal load on the labial surface, and (3) in a 20-degree diagonal load on the lingual surface.

RESULTS

The use of a dowel reduced the peak dentinal stress to 75% of the magnitude of the control. When a vertical force was applied, the magnitudes of stress of the various dowel designs were similar; however, when loaded horizontally, the short dowel produced the greatest dentinal stress concentration, and the tapered dowel showed the greatest stress concentration within the cement layer. Greater deflections and higher stresses were generated with horizontal loading.

CONCLUSION

The dowel and core provided little reinforcement to the remaining tooth. The direction of the functional load had a greater effect than dowel design on maximum stress and displacement. Parallel-sided dowel and cores with a length of 12 mm distributed the stress widely in the restoration and dentin, resulting in the smallest stresses.

Determinants and prognostic significance of spontaneous coronary recanalization in acute myocardial infarction

Spontaneous recanalization (SR) occurs after the onset of acute myocardial infarction (AMI), but its clinical significance in the reperfusion era remains uncertain. We evaluated the determinants and prognostic significance of SR in 196 consecutive patients with AMI who underwent primary angioplasty at our institution. The study population was divided into 2 groups according to the presence (group I, n = 44) or absence (group II, n = 152) of SR (Thrombolysis In Myocardial Infarction [TIMI] anterograde > or = 2 flow on the preintervention angiogram). The primary end point was the occurrence, within 6-weeks after AMI, of death, nonfatal reinfarction, and congestive heart failure. Baseline characteristics were similar between the 2 groups. Peak levels of creatine kinase were lower in group I than in group II (2,500 +/- 1,800 vs 4,000 +/- 2,900 U/L, respectively, p < 0.05). The rate of TIMI flow grade 3 after intervention was higher in group I than in group II (93.2% vs 79.6%, respectively, p < 0.05), and patients in group I had a faster corrected TIMI frame count than those in group II (22.7 +/- 12.4 vs 30.3 +/- 22.8, respectively, p < 0.05). Preinfarction angina (odds ratio [OR] 2.18, 95% confidence interval [CI] 1.10 to 4.33, p < 0.05), heavy thrombi (OR 0.10, 95% CI 0.01 to 0.74, p < 0.05), and good angiographic collaterals (OR 0.12, 95% CI 0.02 to 0.89, p < 0.05) were independent predictors of SR. Death, reinfarction, and severe arrhythmia were not different between the 2 groups. However, heart failure occurred more frequently in group II than in group I (15.1% vs 2.3%, respectively, p < 0.05). The primary end point was also significantly lower in group I than in group II (4.5% vs 18.4%, respectively, p < 0.05). In conclusion, SR in AMI is associated with faster coronary flow, smaller infarct size, and a better clinical outcome after primary angioplasty.

[Chromosome location of a semidwarf gene sd-t in indica rice (O. sativa L.)]

For investigating the linkage group to which the semidwarf gene sd-t belongs, the crosses between Aitaiyin 2(ATY2), a variety of sd-t carrier in indica rice, and marker stocks as well as the trisomic lines of IR36 were made. The results indicated that the sd-t gene was linked to the marker genes Prp-b (Purple pericap b), lg(ligueless) and Wh(White hull). The recombination values estimated were 2.85% +/- 0.52% for sd-t to Prp-b, 27.90% +/- 3.81% for sd-t to lg and 38.62% +/- 2.99% for sd-t to Wh, respectively. It was inferred that the sd-t gene was located on chromosome 4 according to the established relationship between chromosomes and linkage groups.

A novel transformation suppressor, Pdcd4, inhibits AP-1 transactivation but not NF-kappaB or ODC transactivation

Pdcd4 is a novel transformation suppressor that is highly expressed in promotion-resistant (P-) mouse epidermal JB6 cells but not in susceptible (P+) cells. Overexpression of pdcd4 cDNA in stably transfected P+ cells rendered cells resistant to tumor promoter-induced transformation, indicating that elevated expression of Pdcd4 protein is sufficient to suppress neoplastic transformation. To determine whether Pdcd4 suppresses neoplastic transformation through inhibiting known transformation required events, we examined the possibility that pdcd4 inhibited the activation of AP-1 or NF-kappaB dependent transcription or of ornithine decarboxylase (ODC) activity. Activation of AP-1-dependent transcriptional activity was inhibited by pdcd4 expression in a concentration dependent manner. In contrast, Pdcd4 slightly increased NF-kappaB-dependent transcription and did not alter ODC enzymatic activity. Previous studies suggested that activation of AP-1 was required for P+ cell transformation as well as for tumor promotion in vivo. These results indicate that Pdcd4 functions as a transformation suppressor, possibly through inhibiting AP-1 activation in combination with other factors such as enhancing NF-kappaB activation. Pdcd4 may thus constitute a useful molecular target for cancer prevention.

Differential and additive effects of the three conserved isoleucine residues in the promoter -10 binding region on Bacillus subtilis sigma(A) structure and function

The promoter -10 binding region of the Bacillus subtilis sigma(A) factor forms an amphiphilic alpha-helix with three conserved isoleucines located at four-residue intervals. To investigate the structural and functional roles of the three isoleucine residues, we constructed a series of sigA mutants with single and double Ile-to-Ala substitutions on the hydrophobic face of this alpha-helix and isolated intragenic revertants with either same-site or second-site suppressor that partially restores the structural stability and transcription activity of the mutant sigma(A) factors. Our data show that the three conserved isoleucine residues (Ile-194, Ile-198, and Ile-202) are involved in the hydrophobic core packing of sigma(A); they affect differentially and additively the structure and function of sigma(A), with the central isoleucine residue (Ile-198) playing the most important role. By analogy with the crystal structure of a sigma(70) peptide, it is apparent that interdigital interactions exist between the three conserved isoleucine residues and certain hydrophobic amino acids in region 2. 1 of sigma(A). They include at least the van der Waals contacts between Ile-194 and both Leu-145 and Ile-149, between Ile-198 and both Ile-149 and Tyr-153, as well as between Ile-202 and Tyr-153. The same-site suppressors, Val-194 and Val-198, restore the structural stability and transcription activity of sigma(A) by repacking the hydrophobic core of sigma(A). The second-site suppressor (S291F) appears to be allele-specific, but it is not as effective as the same-site suppressors in restoring sigma(A) structure and function.

Finite element stress analysis on the effect of splinting in fixed partial dentures

STATEMENT OF PROBLEM

Long-span fixed partial dentures usually require splinting of multiple abutments to overcome mechanical problems associated with the long edentulous span. Most information and indications for the use of multiple splinted abutments have been empirically derived.

PURPOSE

This study analyzed the stress levels in the teeth and supporting structures of a fixed prosthesis and ascertained how the addition of multiple abutments in a fixed prosthesis modifies the stresses and their deflection.

MATERIAL AND METHODS

The finite element method was used to analyze mechanical behaviors of a prosthesis and its supporting structures when a fixed prosthesis with several designs replaced a mandibular second premolar and a first molar. Variations of the standard finite element model were made by changing the number of splinted teeth and the level of bone support.

RESULTS

A reduction of stress and deflection was observed in the supporting structures when a fixed partial denture was fabricated and teeth were splinted together. Increasing the number of splinted abutments did not reveal a proportional reduction of stress in the periodontium. Stress concentrations were seen in the connectors of prosthesis and in the cervical dentin area near the edentulous ridge.

CONCLUSION

Increasing the number of the splinted abutment did not compensate for the mechanical problems of a long-span fixed partial denture sufficiently.