[Retrospective evaluation of treatment outcomes in immature teeth treated with regenerative endodontic procedures with an over-36-month review].

OBJECTIVE: To evaluate the clinical outcomes of immature teeth treated with regenerative endodontic procedures with an over-36-month review, to identify potential contributing factors of root deve-lopment, and to provide new reference for long-time prognosis of regenerative endodontic procedures. METHODS: We recruited teeth that had undergone regenerative endodontic procedures at the Department of Pediatric Dentistry in Peking University School and Hospital of Stomatology from January 2013 to June 2017 and had a follow-up period of more than 36 months.Clinical and radiographic records were collected.We evaluated the treatment outcomes and summarized different patterns of root development.Changes in root length, root canal wall thickness were compared between preoperative and recall radiographs.A statistical analysis was performed using software SPSS 22.0 to identify potential contributing factors of root development. RESULTS: In this study, 84 teeth were recruited and the mean follow-up period was (44.7±19.3) months.The longest follow-up period was 81 months.Sixty-eight teeth (81.0%) were clinical success with bony healing, and 55 teeth (80.9%) gained the continued root development.Forty teeth completed root development with apical closure.The rate of the apical closure reached 58.8%.Twenty-four teeth gained normal root morphology with the increasing of root length and canal wall thickness and apical closure.The rate of continued root development was 92.5% in teeth with broken central cusp and 58.3% in teeth with trauma, which was statistically significant (P < 0.05).There was a statistically significant difference (P < 0.05) between the root development rates of teeth with different induced bleeding heights (orifice/middle/tip of the root)(92.9%/81.0%/63.2%). CONCLUSION: Most of the teeth treated with regenerative endodontic procedures achieved continued root development with an over 36-month follow-up.However, the patterns of root development were different.The morphology of some teeth were close to the physiological state.Etiology and the height of induced bleeding are two factors significantly associated with the rate of the continued development root.

[Risk factors related to coronary artery occlusion in female patients with ischemic angina pectoris].

Objective: To analyze the risk factors of coronary artery occlusion in female patients with ischemic angina pectoris. Methods: Clinical data of 1 600 patients (666 females and 934 males) who underwent coronary angiography from January 2013 to December 2015 due to angina pectoris in 6 major coronary intervention centers in China were retrospectively analyzed. The clinical characteristics were compared between the female and male groups, and between the non-obstructive coronary artery disease (INOCA) and ischemic obstructive coronary artery disease (IOCA) subgroups of female subjects with angina pectoris. The risk factors related to the degree of coronary artery occlusion in female patients were analyzed. Results: In the enrolled patients who underwent coronary angiography for angina pectoris, female group was older than the male group, and the proportion of patients with hypertension, diabetes and ischemia accompanied by IOCA was significantly higher than that of the male group (P<0.05). Univariate analysis showed that age≥65 years, hypertension, diabetes, and typical angina symptoms were associated with an increased risk of IOCA in female patients with angina pectoris. Multivariate regression analysis showed that age≥65 years old (OR=1.784, 95%CI: 1.146-2.776, P=0.010), hypertension (OR=1.782, 95%CI: 1.201-2.644, P=0.004) and typical angina symptoms (OR=1.642, 95%CI: 1.127-2.393, P=0.010) were independent risk factors for female patients with angina pectoris diagnosed as IOCA. The correlation analysis between the number of risk factors and the type of coronary artery disease obstruction showed that the incidence of INOCA decreased significantly with the increase of the number of risk factors, from 45.5% to 14.2%. The incidence of IOCA increased significantly with the number of risk factors, from 54.5% to 85.8% (P for trend<0.001). Conclusion: The incidence of INOCA in female patients with angina pectoris suspected of coronary heart disease is higher than that of male. The incidence of IOCA increased significantly, and the incidence of INOCA decreased significantly in proportion to the increase of the number of combined risk factors.

[Pulpotomy of human primary molars with novel bioceramic material].

OBJECTIVE: To evaluate the efficacy of iRoot BP Plus, a novel bioceramic material, and mineral trioxide aggregate (MTA) by comparing the clinical and radiographic results of pulpotomy in human primary molars, and to find out the influence factor. METHODS: Children who had at least one primary molar diagnosed as pulpitis, and received pulpotomy in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology from January, 2017 to December, 2018 were searched by the selection criteria in the Electronic Medical Record Database of Peking University School and Hospital of Stomatology. The molars with the pulp capping agents were iRoot BP Plus or MTA were included, and the molars with other pulp capping agents were excluded. Molars using iRoot BP Plus were selected into the experimental group (iRoot BP Plus group). Molars using MTA were selected into the control group (MTA group) using propensity score matching model (1 ∶ 1), considering the gender, age, tooth position, the title of clinician, pulp status, restoration and length of follow-up as the potential influence factor. Basic information, the relevant medical records including symptoms, clinical and radiographic examination before and after operation, intraoperative information and follow up examination records were collected. The success rates were compared and the influence factors were analyzed respectively. RESULTS: The study included 132 children, 178 molars (89 molars from each group) and the mean follow-up time was (462±99) days by December, 2019. In the iRoot BP Plus group, 9 molars failed whilst 6 molars failed in MTA group. The success rate was 89.9% and 93.3%, respectively, showing no significant difference between the two groups. Through Cox proportional risk model analysis, the success rate of iRoot BP Plus was significantly lower when the pulp status was poor, while other factors including age, tooth position, title of clinician and restoration were not found to be associated with the clinical outcome. CONCLUSION: Pulpotomy of human primary molars with iRoot BP Plus has the same effectiveness with MTA. The pulp status is the main factor that influences the outcome of iRoot BP Plus. Further studies with larger sample sizes and longer follow-up terms are needed.

[Orbital cellulitis secondary to odontogenic superior maxillary sinus septum infection: a case report].

A 66-year-old woman presented with recurrent erythema, swelling and pain in her right eye. She had a history of extraction of the right upper second molar 5 months ago with subsequent development of an abscess which was incised and drained 4 months ago. Orbital CT scan revealed the formation of subperiosteal sinus cavity with an abscess in the right maxillary sinus and infraorbital foramen. The diagnosis was orbital honeycombing caused by odontogenic maxillary sinus septum infection. Utilizing the anterior lacrimal recess approach under nasal endoscope,incision and drainage of ocular abscess and debridement and drainage of right orbital abscess plus partial resection of the inner wall of the jaw were performed successfully with maxillary sinus septal drainage and maxillary sinus opening. The patient improved significantly after the operation.

[Effects of three self-etch adhesives and mild salivary contamination on the bonding durability of deciduous teeth].

OBJECTIVE: To compare the bonding durability of three different self-etch adhesives to primary enamel and dentin, and to investigate the effect of mild salivary contamination followed by air drying on the bonding durability. METHODS: Two hundred and forty enamel specimens were divided randomly into 16 groups (n=15/group)according to the adhesive system [self-etch adhesives: Clearfil SE Bond(SE), AdperTM Easy One (EO), Scotchbond Universal (SBU); total-etch adhesive: AdperTM Single Bond Plus(SL)], contamination status (non-contaminated vs. salivary-contaminated) and storage condition (stored in distilled water for 24 h vs. aging mode 5 000 thermal cycles in 5 ℃ and 55 ℃). Two hundred and forty dentin specimens were assigned in the same way. Shear bond strength for 12 specimens in each group were measured. The adhesive interface for the residual specimens in each group was observed by scanning electron microscopy(SEM). Data were analyzed by three-way analysis of variance and Tukey test(P < 0.05). RESULTS: For primary enamel, total-etch adhesive showed higher initial shear bond strength values (28.92±1.83) MPa and shear bond strength values (27.27±3.03) MPa after thermal cycles compared with the other groups, and the difference between the groups was statistically significant (P < 0.01). Shear bond strength values of EO decreased significantly in salivary-treated groups, regardless of storage conditions, and the difference was statistically significant (P < 0.01). For primary dentin, shear bond strength values of EO decreased significantly in salivary-treated groups after 24 h (P < 0.01). After 5 000 thermal cycles, total-etch adhesive showed significantly lower shear bond strength values (14.31±1.97) MPa compared with the other groups, and the difference between the groups was statistically significant (P < 0.01), and shear bond strength values of EO were significantly lower than those in SE and SBU groups (P < 0.01), regardless of contamination status. CONCLUSION: Total-etch adhesive SL has better bonding durability to primary enamel. SE and SBU have better bonding durability to primary dentin and have a certain resistance to salivary contamination, while the bonding performance of EO is compromised greatly by mild salivary contamination followed by air drying.

[Nearinfrared light transillumination for detection of incipient proximal caries in primary molars].

OBJECTIVE: To evaluate the practical value of nearinfrared light transillumination (NILT, DIAGNOcam) on detection of incipient proximal caries in primary molars. METHODS: In this study, 4-9-year-old children with suspicious proximal lesions in primary molars were recruited. The target teeth were examined with clinical examination, bitewing radiograph and DIAGNOcam. And the caries indexes were rated as 0 (no caries), 1 (caries reaching outer 1/2 enamel), 2 (caries reaching inner 1/2 enamel), and 3 (dentine caries). Those primary molars with at least one of the adjacent molars according with the criteria of invasive treatment, i.e. the teeth were diagnosed as caries reaching inner 1/2 enamel or dentine with at least two detection methods, were included. The target teeth with caries index ≥2 accepted the invasive treatment. And the caries status of the adjacent teeth was observed under direct vision and those teeth of caries index ≥2 would also accept the invasive treatment. The relationship of lesions to enamel-dentine junction (EDJ) were recorded and used as reference standard to compare the sensitivity, specificity and accuracy of those three methods in detecting the incipient proximal caries in primary molars. RESULTS: In this study, 36 children with 104 suspicious proximal lesions in primary molars were recruited, of which 5 were diagnosed as no caries, 20 were diagnosed as superficial enamel caries, and 79 accepted invasive treatment, of which 22 were diagnosed as EDJ caries, and 57 as dentine caries. The sensitivity of clinical examination, bitewing radiograph, and DIAGNOcam were 68.69%, 81.82%, 78.79%, respectively. The specificity were 100.00%, 100.00%, 80.00%, and the accuracy were 75.96%, 85.65%, 78.85%, respectively. As for superficial enamel caries, the sensitivity of clinical examination was lowest, only 10%, while DIAGNOcam was 60%, higher than 40% of bitewing radiograph. As for EDJ caries, the sensitivity of bitewing radiograph was highest as 86.36%, followed by DIAGNOcam 72.73% and clinical examination 68.18%. As for dentine caries, the sensitivity of the three detection methods were higher than 85%, of which bitewing radiograph was the highest as 94.74%. CONCLUSION: The accuracy of DIAGNOcam in detecting incipient proximal caries in primary molars was comparable to that of bitewing radiograph. It was safe, and convenient with no exposure to radiation, which was applicable to be used in pediatric dentistry.

Compound bioengineering protein supplementation improves intestinal health and growth performance of broilers.

Currently, antimicrobial peptides (AMPs) are of growing interest as potential substitutes for antibiotic growth promoters in animal production. The present study was conducted to evaluate the effects of dietary supplementation of bioengineering artificial Parasin I protein (API) and artificial plectasin protein (APL) (named as compound bioengineering protein, CBP) on growth performance and intestinal health of broilers. A total of 450 one-day-old Arbor Acres male healthy broilers were randomly allotted to 5 dietary groups with 10 replicates of 9 individuals in each replicate and supplemented with 0, 250, 500, 750, and 1,000 mg/kg CBP for 6 wk. Dietary CBP supplementation increased (P < 0.01) body weight (6 wk), average daily gain (0-6 wk), and average daily feed intake (3-6 wk and 0-6 wk). CBP addition enhanced antioxidant capacity, which was accompanied by the higher (P < 0.05) activity of serum total antioxidant capacity (T-AOC) (750 mg/kg), jejunal glutathione peroxidase (750 mg/kg), and T-AOC (500 and 1,000 mg/kg). Dietary CBP addition improved intestinal health, reflecting by the increased (P < 0.05) villus height to crypt depth ratio in the duodenum, the upregulated (P < 0.01) mRNA levels of claudin-1 (500 and 750 mg/kg) in the ileum, the downregulated (P < 0.01) mRNA expression of occludin (500 mg/kg) in the duodenum and claudin-1 (500 mg/kg) and occludin (500 and 750 mg/kg) in the jejunum, and the upregulated mRNA expression of (P < 0.01) mucin2 (MUC2) (1,000 mg/kg) in the duodenum. In addition, CBP upregulated (P < 0.01) IL-10 (1,000 mg/kg) in duodenum and ileum, and downregulated (P < 0.05) the mRNA expression of IL-6 (750 and 1,000 mg/kg), interferon-γ (1,000 mg/kg) in the jejunum and TNF-α (250 mg/kg) in the ileum. Furthermore, dietary CBP increased (P < 0.01) the abundance of total bacteria and Lactobacillus (500 and 750 mg/kg), and reduced (P < 0.05) the abundance of Escherichia coli (750 mg/kg) in the cecum. In conclusion, CBP supplementation enhances the antioxidant capacity, intestinal health, immune function, and ameliorates the gut microflora population, thus improving the growth performance of broilers. Dietary supplementation of 750 mg/kg CBP exhibits a better beneficial effect.

[Enzyme immunoassay for the determination of hexestrol in meat].

An indirect competitive enzyme-linked immunosorbent assay (ELISA) of hexestrol (HES), an antibiotic forbidden for use in livestock farming, has been developed. Conditions of ELISA have been optimized by varying the concentrations of the coating conjugate (HES-ovalbumin), anti-HES antiserum, casein, and Tween 20. In the absence of Tween 20 in the reaction mixture, the detection limit (IC10) equaled 0.01 ng/ml, IC50 equaled 0.17 ng/ml, and the working range (IC20-IC80) equaled 0.03-0.86 ng/ml, while, in the presence of 0.05% Tween 20, these values equaled 0.05 ng/ml, 2.9 ng/ml, and 0.26-32.0 ng/ml, respectively. Standard deviation of the analysis results did not exceed 5.4%. If ELISA was performed in the absence of detergents, the recovery value upon HES determination in spiked beef samples ranged from 74 to 147%.

[A randomized clinical trial of two bioceramic materials in primary molar pulpotomies].

Objective: To compare the success rates of iRoot BP Plus and mineral trioxide aggregate (MTA) used as pulp capping materials respectively in pulpotomies of human primary molars and to evaluate the clinical efficacy of iRoot BP Plus. Methods: Children who had at least one pair of carious primary molars and needed to receive pulpotomy under general anesthesia were selected in the present split-mouth trail from August to December, 2018. Each pair of the molars was randomly divided into iRoot BP Plus (experimental group) and MTA group (control group). Children were recalled after 3, 6 and 12 months of treatment both for clinical and radiographic evaluations. Relevant medical and radiographic records were collected. Success rates of two groups were compared and influence factors were analyzed. Results: Totally 20 children (10 boys and 10 girls), 28 pairs of split-mouth molars (56 molars, 28 in experimental group and 28 in control group) were included in the study. At the end of the study, 23 pairs of molars were received the 12-month follow-up. The success rates of 3, 6 and 12 months were 96% (25/26), 92% (22/24) and 87% (20/23) in the experimental group, and 100% (26/26), 96% (23/24), 96% (22/23) in the control group, respectively. There were no significant differences between each of the follow-ups in two groups (P>0.05). The success rate of iRoot BP Plus was significantly influenced by the time of hemostasis after amputating the coronal pulp (P<0.05). Conclusions: Pulpotomies of human primary molars with either iRoot BP Plus or MTA had favorable treatment outcomes. The iRoot BP Plus could be a promising biomaterial in pulpotomy.

[Development of a deep learning based prototype artificial intelligence system for the detection of dental caries in children].

Objective: To develop a prototype artificial intelligence image recognition system for detecting dental caries, especially those without cavities, in children. Methods: Seven hundred and twelve intraoral photos, which were taken by dental professionals using a digital camera from October 2013 to June 2020 in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, were collected from the children who received dental treatment under general anesthesia. The well-documented post-treatment electronic dental record of each child was identified as label standard to determine whether the teeth were carious and the type of caries types such as caries that had become cavities (caries with cavities), pit and fissure caries that had not become cavities (pit and fissure caries) and proximal caries which the marginal ridge enamel had not been destroyed (proximal caries). The various teeth and caries types were labeled by pediatric dentists using VoTT software (Windows 2.1.0, Microsoft, U S A). There were five labeled groups: pit and fissure caries, approximal caries, non-carious approximal surfaces, caries with cavities and teeth without caries (including intact fillings). Each group was randomly divided into training dataset, validation dataset and test dataset at a ratio of 6.4∶1.6∶2.0 by using random number table. After using the labeled training dataset for deep learning training, a deep learning-based artificial intelligence (AI) image recognition system for detecting dental caries was established, with the caries probability greater than 50.0% as the criterion for determining caries. Sensitivity and accuracy were used as indicators of recognition specificity. Results: Seven hundred and twelve single-jaw intraoral photographs were segmented and annotated into 953 pit and fissure caries, 1 002 approximal caries, 3 008 caries with cavities, 3 189 teeth without caries and 862 non-carious approximal surfaces, totaly 9 014 labels. The sensitivities and specificities of the test set were 96.0% and 97.0% for caries with cavities, 95.8% and 99.0% for pit and fissure caries and 88.1% and 97.1% for approximal caries. Conclusions: The current AI system developed based on deep learning of the intra-oral photos in the present study showed the ability to detect dental caries. Furthermore, the AI system could accurately verify different types of dental caries such as caries with cavities, pit and fissure caries and proximal caries.

[Retrospective analysis of pulp revascularization in immature permanent teeth with diffuse pulpitis].

Objective: To evaluate the treatment effectiveness of revascularization in immature permanent teeth with diffuse pulpitis and to provide an alternative approach for the treatment of these teeth. Methods: Clinical and radiographic data were collected from 17 immature permanent teeth which were diagnosed as diffuse pulpitis and with their pulp extirpated at Emergency Department of Peking University School and Hospital of Stomatology. All these teeth were treated using pulp revascularization at Department of Pediatric Dentistry. Clinical success rate was then evaluated based on the clinical and radiographic findings. The increase of root length and dentin wall thickness of the revascularized teeth and the contralateral control teeth were measured and compared according to the preoperative and recall periapical radiographs. Results: The average follow-uptime is (25.8±9.9) months (12-46 months). Totally 13 out of the 17 teeth showed normal clinical and radiographic manifestation and achieved the increasein root length and dentin wall thickness. They met criteria for success treatment. The rest 4 out of the 17 teeth also showed root length and dentin wall thickness increaseand apical foramen closure. However, periapical inflammations were observed during 12 to 36 monthfollow-ups. These cases were recognized as failed. In all the17 teeth, the increase of root length and dentin wall thickness was not significantly different between the revascularized teeth and the contralateral control teeth (P>0.05). Conclusions: Pulp revascularization in young permanent teeth with diffuse pulpitis resulted in similar clinical outcomes in root development and root canal wall formation compared with the contralateral control teeth. However, reinfection might occur during long-term follow-up.

Effects of adenine nucleotide translocase inhibitors on dinitrophenol-induced Ca2+ efflux from pig heart mitochondria.

Bongkrekic acid and atractyloside, inhibitors of adenine nucleotide translocase, do not inhibit Ca2+ uptake and H+ production by pig heart mitochondria. However, bongkrekic acid, but not atractyloside, inhibits dinitrophenol-induced Ca2+ efflux and H+ uptake. Conversely, ruthenium red blocks Ca2+ uptake and H+ production but does not prevent dinitrophenol-induced Ca2+ efflux and H+ uptake by mitochondria. These results suggest that mitochondrial Ca2+ uptake and release exist as two independent pathways. The efflux of Ca2+ from mitochondria is mediated by a bongkrekic acid sensitive component which is apparently not identical to the ruthenium red sensitive Ca2+ uptake carrier.

Divalent cation-activated ATP hydrolysis by mitochondrial ATP'ase--mechanism for energy depletion in ischemic reperfused myocardium.

Recovery of high-energy compounds by ischemic myocardium is believed to be important for its return to normal functioning. While it has been previously shown that oxidative phosphorylation is markedly reduced in mitochondria isolated from ischemic myocardium in the presence of all substrates, alterations in ATPase activity have not been confirmed. This study demonstrates that, although the rate of ATP hydrolysis produced by mitochondria isolated from 2-hr ischemic myocardium does not significantly differ from that produced by non-ischemic mitochondria, the rate produced by 2-hr ischemic, 2 hr reperfused mitochondria is significantly higher. Also, Ca++ content was observed to be higher in reperfused than in non-reperfused ischemic mitochondria. The addition of EDTA, EGTA, or oligomycin to the reperfused ischemic mitochondria resulted in the inhibition of ATPase activity. These results indicate that mitochondrial ATPase in ischemic myocardium is activated by Ca++ ions and that ischemic reperfused myocardium may contain mitochondria with uncontrolled ATPase activity such that high energy phosphate supplies are excessively depleted when the cells are reperfused.

Effects of dideoxyforskolin on proteoglycan synthesis and structure in embryonic chick chondrocyte cultures.

1,9-Dideoxyforskolin inhibits proteoglycan synthesis and xyloside-initiated glycosaminoglycan (GAG) synthesis in chick embryo chondrocytes. Dideoxyforskolin does not affect the length of xyloside-initiated GAG chains secreted into the medium but chains from the dense proteoglycan secreted into the medium appear slightly longer. Incorporation of labeled serine into the dense proteoglycan and subsequent digestion with Pronase revealed a dramatic decrease in percent of total radioactivity associated with GAG chains in the proteoglycan from cultures treated with forskolin or dideoxyforskolin. These observations suggest that these diterpenes have a specific inhibitory effect on chain initiation reactions and thus may be useful tools in the study of proteoglycan synthesis and processing.

Ventricular performance and biochemical alteration of regional ischemic myocardium after reperfusion in the pig.

Reperfusion of acutely ischemic myocardium may cause profound alterations in left ventricular wall performance and metabolism. This study evaluates regional left ventricular wall thickness, analyzes metabolic and biochemical alterations, and examines tissue hemorrhage during 15, 30, and 120 minutes of myocardial ischemia, each followed by 120 minutes of reperfusion. Reperfusion after 15 minutes of ischemia showed nearly normal ventricular wall thickening and motion, intact metabolic and biochemical function, and no tissue hemorrhage. However, reperfusion after 30 and 120 minutes of ischemia was associated with ventricular wall thickening and failure to resume systolic and diastolic wall motion. Furthermore, adverse metabolic and biochemical alterations and reperfusion zone hemorrhaging increased proportionally with the duration of ischemia. These findings suggest critical myocardial damage occurring between 15 and 30 minutes of ischemia in an animal model without preexisting coronary collateral circulation. The observed metabolic and biochemical changes are consistent with irreversible cell membrane defects, allowing calcium ion accumulation and thus adversely affecting diastolic relaxation and systolic thickening.

Molecular epidemiology and mutations at gyrA and parC genes of ciprofloxacin-resistant Escherichia coli isolates from a Taiwan medical center.

Sixty-five ciprofloxacin-resistant clinical Escherichia coli isolates were collected from a Taiwan Medical Center from December 1998 to February 1999. All 65 clinical isolates were resistant (MICs > or = 4 microg/mL) to the following fluoroquinolones: ofloxacin, levofloxacin, sparfloxacin, and trovafloxacin. These isolates were cross-resistant to chloramphenicol (65 isolates, 100%), tetracycline (65 isolates, 100%), cefuroxime (64 isolates, 98.5%), ampicillin (57 isolates, 87.7%), gentamicin (53 isolates, 81.5%), and cephalothin (24 isolates, 36.9%). Pulsed-field gel electrophoresis (PFGE) revealed a high diversity among the genomes of these isolates and indicated that clonal spread was not responsible for the prevalence of ciprofloxacin resistance in the hospital. Sequencing of the polymerase chain reaction (PCR) amplified products of the quinolone resistance determining regions (QRDRs) of gyrA and parC showed that all isolates carrying double mutations in gyrA at codon 83 and 87 and at least one parC mutation at codon 80 and/or 84. The mutation at codon 83 of GyrA from serine to leucine (S83L) was present in all the clinical isolates. The most prevalent pattern was the S83L mutation and the mutation at codon 87 from an aspartate to an asparagine (D87N) of GyrA plus a mutation from a serine to an isoleucine (S80I) at codon 80 of ParC (63.2%). This indicated that the presence of high-level resistance to quinolones in clinical E. coli isolates were associated with mutations at hot spots, codon 83 and 87 in GyrA and followed by subsequent mutation in either codon 80 and/or 84 in ParC.

Calcitonin gene-related peptide-induced preconditioning improves preservation with cardioplegia.

BACKGROUND: Our recent work has shown that calcitonin gene-related peptide (CGRP) may play an important role in mediation of ischemic preconditioning. Therefore, we tested the hypothesis that CGRP-induced preconditioning protects against myocardial damage after prolonged cardioplegic arrest in isolated rat hearts. METHODS: Six groups were studied: the control, ischemic preconditioning, and CGRP-pretreated groups for both 4- and 8-hour hypothermic ischemia. All hearts were arrested using St. Thomas Hospital cardioplegia, and then reperfused with normothermic Krebs-Henseleit solution for 60 minutes after the 4- or 8-hour hypothermic ischemic period. Hearts were subjected to two cycles of 5-minute ischemia and 10-minute reperfusion in the ischemic preconditioning group. In the CGRP-pretreated group, Krebs-Henseleit solution containing CGRP (5 x 10(-9) mol/L) was substituted for the ischemic period. RESULTS: At 30 minutes of reperfusion after 4-hour storage, left ventricular pressure (mm Hg) and its first derivative (dp/dtmax, mm Hg/s) in the control, ischemic preconditioning, and CGRP groups were 65.2 +/- 5.93 and 1,170 +/- 119, 94.13 +/- 4.93 and 1,825 +/- 145.83, and 85.47 +/- 4.17 and 1,900 +/- 123.13, respectively (p < 0.01). After 8-hour storage, left ventricular pressure (mm Hg) and dp/dtmax (mm Hg/s) in the same groups were 51.07 +/- 5.83 and 815 +/- 107.17, 83.47 +/- 6.54 and 1,480 +/- 120.91, and 84.8 +/- 8.49 and 1,396 +/- 126.16 (p < 0.01). Ischemic preconditioning and CGRP-induced preconditioning also significantly reduced the release of myocardial enzymes. CONCLUSIONS: The present studies suggest that ischemic preconditioning protects against ischemia-reperfusion injury even after 8 hours of hypothermic preservation in isolated rat hearts, and that CGRP exerts preconditioning-like cardioprotection.

Calcitonin gene-related peptide-induced preconditioning protects against ischemia-reperfusion injury in isolated rat hearts.

Our previous work has suggested that the calcitonin gene-related peptide (CGRP) receptor antagonist CGRP-(8-37) can abolish the protective effect of ischemic preconditioning in the isolated rat heart. Therefore we tested the hypothesis that CGRP- or capsaicin-induced preconditioning protects against ischemia-reperfusion injury in the isolated perfused rat heart. Thirty minutes of global ischemia and 30 min of reperfusion caused a significant cardiac contractile dysfunction, ventricular arrhythmia, and an increased release of creatine phosphate kinase. Pretreatment with CGRP or capsaicin, which evokes release of CGRP from cardiac sensory nerves, for 5 min produced a significant improvement of cardiac function, a reduction in the incidence of ventricular arrhythmia, and a decrease in the release of creatine phosphate kinase. However, the cardioprotection provided by CGRP- or capsaicin-induced preconditioning was abolished by CGRP-(8-37) and ruthenium red, respectively. These findings suggest that CGRP- or capsaicin-induced preconditioning protects against ischemic myocardial injury. The present results also suggest that CGRP may be an endogenous myocardial protective substance in the rat.

Isolation of non-tuberculous mycobacteria from hospital cockroaches (Periplaneta americana).

This study attempted to isolate mycobacteria from hospital and household cockroaches from 90 hospitals and 40 households in Kaohsiung City and Kaohsiung County, South Taiwan. Among 203 cockroaches (139 Periplaneta americana and 64 Blattella germanica) collected from the hospitals, six Mycobacterium spp. were isolated and identified by polymerase chain reaction-restriction fragment length polymorphism analysis. In 12 cockroaches (P. americana): four Mycobacterium kansaii, three Mycobacterium xenopi, two Mycobacterium gordonae, one Mycobacterium hemophilium, one Mycobacterium fortuitum, and one Mycobacterium avium. However, no mycobacteria were obtained form the hospital B. germanica or 226 household cockroaches (123 P. americana and 103 B. germanica). As cockroach infestation occurs commonly in the hospital environment, they may potentially be implicated as a cause of hospital-acquired infections due to non-tuberculous mycobacteria.

An efficient method for the culture of Helicobacter pylori from gastric biopsies with two-section petri dishes.

PURPOSE: Helicobacter pylori is the principal cause of chronic gastritis and is strongly associated with peptic ulcer disease and gastric cancer, as well as with gastric lymphoma (mucosa-associated lymphoid tissue [MALT] type). H. pylori could be recovered by many kinds of media, however, it could not be detected efficiently. This study was trying to ameliorate the isolation and detection rate with selective and non-selective media. METHODS: First, type strain (ATCC 43504) was cultured with twelve different kinds of sheep blood agar based on brain heart infusion medium for five days. Then five better non-selective media and five selective media were chosen for the biopsy, which were incubated at 37 degrees C in a microaerophilic incubator for five days. Endoscopic biopsies were collected from 623 patients at Kaohsiung Medical University Hospital. RESULTS: It was found that non-selective media, which contain 5% modified chocolate agar (the ratio of fresh and heated sheep blood is 2) with 1% Isovitalex, had the best detection rate (91.1 +/- 0.6)%. Furthermore, 5% modified chocolate agar with 1% Isovitalex and 1% antibiotics would increase the detection rate to (97.1 +/- 0.3)%. CONCLUSIONS: According to Ansorg's method, the best detection rate (98.4 +/- 0.7)% could be obtained with two-section petri dishes which had 5% modified chocolate agar with antibiotics and the other without antibiotics.