[Oral health and hygiene behavior in chronic renal failure patients].

PURPOSE: To investigate the oral health and hygiene behavior of chronic renal failure(CRF) patients in Shenzhen, so as to provide basis for formulating education for them. METHODS: The history of renal failure, oral health status and oral health care behavior of 336 patients with chronic renal failure(CRF) in the hemodialysis center of Shenzhen Second People's Hospital were investigated by questionnaire and oral examinations. RESULTS: At an average, dialysis was required for 3.2 years. The main cause of renal failure was glomerulonephritis in 49.11% of patients, hypertensive kidney lesion in 19.35% and diabetic nephropathy in 15.77% of patients; 77.8% of them kept brushing teeth two or more than two times every day; 72.9% patients suffered from oral problems such as toothache in recent 12 months. The rate of visiting a dentist when having complaints was 21.7%. CONCLUSIONS: The state of oral health of CRF is worse than the general population of comparable age in China, while their hygiene behavior is better than the corresponding reference general population. However, their consciousness of dental treatment is poor. Therefore, health education for CRF patients should include knowledge about oral diseases complicated with CRF and correct medical philosophy.

Study on the application of oral digital design in aesthetic restoration of anterior teeth of cleft lip/palate patients.

OBJECTIVES: A study was conducted to investigate the clinical effects of oral digital design on the aesthetic restoration of anterior teeth of cleft lip/palate patients. METHODS: Nine adult cleft lip/palate patients who need aesthetic restoration of anterior teeth were recruited. Digital information of patients' dental arches, the surrounding soft tissue and face were captured by digital camera and scanner. The aesthetic analysis and design were conducted using keynote and 3shape software and were demonstrated to the patients. The optimized treatment plan was ensured by communicating with the patients. Digital wax-up models were exported and printed into resin diagnostic models, which were then utilized in the treatment process to guide the doctors and the technicians in tooth preparation and in making the final restorations, respectively. The adhesive procedure was completed after satisfactory try-in. Aesthetics assessment was conducted in accordance with the anterior esthetic evaluation form. The scores of patient's satisfaction were recorded on a questionnaire containing six items of aesthetic index and doctor-patient communication. Patients were interviewed and examined after 1, 3, 6, and 12 months, respectively, and the clinical effects of restorations were evaluated. RESULTS: All nine patients had satisfactory clinical results. The aesthetic defects of the patients were effectively addressed. All treatments met the requirements of the preoperative digital designs. The patients' scores were all above 90 on the satisfaction scale. At 12 months after the operation, the clinical effects of restorations of all cases achieved A class in each evaluation indicator. CONCLUSIONS: For cleft lip/palate patients with esthetic defect in the anterior teeth, the digital design plays an important role in optimizing the treatment plan and guides the whole treatment process. This design can help clinicians achieve predictable satisfactory aesthetic results.

Metabolism of Peptide Drugs and Strategies to Improve their Metabolic Stability.

BACKGROUND: Despite the therapeutic use of peptides is limited because of their metabolism in vivo, there are no systematic reviews explaining degradation of peptides by peptidases. This review summarizes peptidases present in the tissues and metabolic characteristics of peptides, and provides recent strategies for improving the metabolic stability of peptides. METHOD: We reviewed a number of peptidases including their functional groups, tissue localization and cleavage specificity. Given the broad distribution of peptidases in the body, several tissues, such as the liver, kidney, lung, blood, nasal epithelial cells, placenta and skin, have the capacity to metabolize peptides. We compared the metabolic characteristics of peptides in these tissues and then summarized strategies for improving peptide stability. RESULTS: In addition to the primary organs including liver, kidney, gastrointestinal tract and blood involved in peptide metabolism, other organs such as the lung, skin, placenta and nasal mucosa may also play a role in peptide degradation. At present, the main measures to improve the stability of the peptide include N- and/or C-terminal modification or substitution, D-amino acid or unnatural amino acid substitution, cyclization, backbone modification, nanoparticle formulations and increased molecular mass. CONCLUSION: This review summarized the key in vivo peptidases and their tissue distribution characteristics, and presented strategies to improve the metabolic stability and bioavailability of peptide drugs. These viewpoints will benefit the further development and utilization of peptide drugs.

Simultaneous determination of five novel luteinizing hormone-releasing hormone antagonists by LC-MS and pharmacokinetics in rats following cassette dosing.

Long acting luteinizing hormone-releasing hormone (LHRH) antagonists designed to be protease-resistant were a series of novel decapeptides structurally similar to LHRH. In the present work, a high-throughput method based on a LC-MS/MS has been developed for the simultaneous determination of pharmacokinetics of five LHRH antagonists in rat via cassette dosing. The method was performed under selected reaction monitoring (SRM) in positive ion mode. The analytes were extracted from rat plasma by liquid-liquid extraction with acetonitrile. Chromatographic separation of the analytes was successfully achieved on a Hypersil Gold (100mm×2.1mm, 3µm) using a mobile phase composed of acetonitrile-water (30:70) containing 0.05% (v/v) formic acid. The result showed good linearity and selectivity were obtained for all antagonists. The limits of quantification of the five LHRH antagonists were from 5 to 10ng/mL. The average extract recoveries in the rat plasma were all over 72%. The intra-day and inter-day precisions (R.S.D. %) were all within 10% and the accuracy was ranged from 92.54 to 109.05%. This method has been successfully applied to the pharmacokinetic studies of the five LHRH antagonists. The results indicated that the plasma drug concentrations versus time curves after intravenous injection of five antagonists via cassette dosing were all fitted to a two-compartment model. The pharmacokinetic parameters of five LHRH antagonists suggested that LY616 could be the more stable candidate drugs and optimized as the candidate drug for further study. Our studies enabled high-throughput rapid screening for pharmacokinetic assessment of new peptide candidates, and provided abundant information on the metabolic properties of these LHRH antagonists.

Metabolic stability of long-acting luteinizing hormone-releasing hormone antagonists.

Long-acting luteinizing hormone-releasing hormone (LHRH) antagonists designed to be protease resistant consisted of a series of novel decapeptides structurally similar to LHRH. The aim of this study was to evaluate the in vitro metabolic stability of the LHRH decapeptides using pancreatin and homogenates models and identify the metabolites in rat liver homogenate for the purpose of illustrating the metabolic features of the decapeptides. The major metabolites in rat liver homogenate were identified by LC-ESI-MS(n). The half-lives of the 11 LHRH decapeptides were from 44 to 330 min in the pancreatin model. The half-lives of the five decapeptides in rat liver, kidney and lung homogenates were between 8 and 462 min. The most stable decapeptides were the LY616 and LY608 peptides with half-lives of 36 min in liver homogenate. Two major cleavage sites were found by analysing the metabolites of the LY618 peptide in rat liver homogenate, between the Pal(3)-Ser(4) and the Leu(7)-Ilys(8) peptide bonds. The major metabolites were produced via cleavages of peptide bonds at these sites, and further metabolic reactions such as hydroxylation, oxidative dechlorination, alcohol dehydration and isopropyl dealkylation were also observed.

1-Bromo-2-(4-methoxy-phen-oxy)ethane.

In the crystal structure of the title compound, C(9)H(11)BrO(2), mol-ecules are stacked parallel to the b-axis direction, forming double layers in which the molecules are arranged head-to-head, with the bromo-methyl groups pointing towards each other.

2-(2,4,6-Trichloro-phen-oxy)ethyl bromide.

In the title compound, C(8)H(6)BrCl(3)O, there is a weak intra-molecular C-H⋯Cl hydrogen bond involving the O bound methylene group. Intermolecular Cl⋯Cl contacts [3.482 (2) Å] are present in the crystal structure.

1-(4-Methyl-1-naphth-yl)ethanone.

In the mol-ecule of the title compound, C(13)H(12)O, the two aromatic rings are oriented at a dihedral angle of 2.90 (3)°. An intra-molecular C-H⋯O hydrogen bond results in the formation of a non-planar six-membered ring, which adopts an envelope conformation. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules.

1-(3-Bromopropoxy)-4-chlorobenzene.

In the mol-ecule of the title compound, C(8)H(8)BrClO, the Cl atom lies slightly out of the aromatic ring plane [displacement = 0.072 (3) Å]. In the crystal structure, a π-π contact between the phenyl rings [centroid-centroid distance = 3.699 (3) Å] may stabilize the structure. There also exists a C-H⋯π contact between the methyl-ene group and the chloro-phenyl ring.

[Effects of aldosterone and spironolactone on the proliferation and collagen synthesis of hepatic stellate cells in rats].

OBJECTIVE: To investigate the effects of aldosterone and spironolactone on the proliferation and collagen synthesis of hepatic stellate cells. METHODS: Rat HSC were incubated with aldosterone or spironolactone, an aldosterone receptor antagonist at different concentrations. The proliferation of HSC was measured by (3)H-thymidine incorporation, and the collagen synthesis by (3)H-Proline. The changes of HSC cycle were analyzed by FCM. RESULTS: At dose of 10(-4) mol/L, ALD increased the incorporation of (3)H-TdR and (3)H-Pro (P < 0.05), but didn't at the lower doses. Spironolactone significantly inhibited HSC proliferation and collagen synthesis. The effective concentration was among 10(-4) mol/L - 10(-6) mol/L, and in dose-dependent manner. The percentage of G(1) phase of the cell cycle was significantly increased, and the cell proliferation suppression of spironolactone is associated with cell arrest in G(1) phase. Co-stimulation with aldosterone and spironolactone did not have significant effects on HSC proliferation and collagen synthesis compared with the control group. CONCLUSION: The proliferation and collagen synthesis of HSC might be enhanced by ALD at higher concentration, but was inhibited by spironolactone.

H2 strain attenuated live hepatitis A vaccines:protective efficacy in a hepatitis A outbreak.

AIM:To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) outbreaks.METHODS:With the permission of their parents, 5551 pre-school and grade 1-3 primary school children were inoculated with 1 dose (10(6.5) TCID(50)) of H2 strain vaccines in a nonrandomized, controlled trial conducted in Fucheng County, Hebei Province in May 1997.Another 6485 children in the same grades and compatible in gender and age were enrolled as controls. Epidemiological and serological survey was conducted to evaluate the protective efficacy of the vaccines. ELISA was used to detect serum IgM anti-HAV.RESULTS:HA outbreak started in early May 1998, peaked in the middle of the same month, and lasted about 80 days. Overall 302 HA cases were found, 192(63.58%) were 5-9 years old. One vaccinee and 25 control cases were found to have hepatitis A, which account for 0.28% (1/356) and 5.92% (25/422) of all vaccinees and controls in the 14 villages, respectively. The protective efficacy of vaccines was 95.27% (95% CI: 85.83%-104.72%). In subjects tested for anti-HAV IgM from 13 villages, 1(0.40%) overt and 11(4.06%) asymptomatic HAV cases were found in 271 vaccinees but 21(6.69%) of overt and asymptomatic ones were found in 314 controls.CONCLUSION:H2 strain vaccines were excellent in preventing overt hepatitis A,but not so effective in preventing asymptomatic hepatitis A virus infection.A booster dose might be needed to get permanent reliable immunity.