AIMTo establish the differential scanning calorimetric (DSC) methodology for controlling the crystal-type B form of nateglinide.

METHODSAccurately weighed pure dried (P2O5 as desiccant for 4 h at 80 degrees C in vacuum) fine powder of crystal-type B and H of nateglinide were measured dQ/dT by DSC at heating rate of 10 degrees C. min-1 and temperature between 100 degrees C and 200 degrees C to calculate the enthalpy delta HB and delta HH. Accurately weight a series of uniform mixtures of crystal-type B and H of dried fine powder of nateglinide in different proportions. The enthalpy of the mixtures is measured by DSC as above to calculate the enthalpy (sigma delta H). Using B% as X, sigma delta H as Y, the regression equation was obtained. According to this equation, the unknown composition of mixed crystal was evaluated by the sigma delta H values. The method was used to control the limitation of crystal-type B of nateglinide by the sigma delta H value of mixture of known composition as reference.

RESULTSThe results measured from different laboratories showed that the repeatability was 0.61% and the recoveries were 86.2%-127% when the amounts of crystal-type B were between 0-15%.

CONCLUSIONThis method can be used to evaluate the crystal-type B composition of nateglinide.

Calorimetry, Differential Scanning ; Crystallization ; Cyclohexanes ; chemistry ; Phenylalanine ; analogs & derivatives ; chemistry ; Quality Control

Animals ; Biopterin ; analogs & derivatives ; therapeutic use ; Genetic Therapy ; Humans ; Phenylalanine Ammonia-Lyase ; administration & dosage ; Phenylketonurias ; therapy

OBJECTIVETetrahydrobiopterin (BH(4)) responsive phenylalanine hydroxylase (PAH) deficiency is one of the forms of phenylketonuria (PKU). The aim of this study was to screen and diagnose BH(4) responsive PAH deficiency, to further understand its clinical characteristics, and to provide evidence for applying BH(4) drug therapy.

METHODSBH(4) 20 mg/kg loading test was performed in 73 patients with hyperphenylalaninemia (HPA) (47 males and 26 females), the mean age was 1.93 months. Combined phenylalanine (100 mg/kg) and BH(4) loading test was performed if patients had a basic blood phenylalanine concentration less than 600 micromol/L. The urine pterin profile analysis and the dihydropteridine reductase (DHPR) activity in dry blood filter spot were analyzed simultaneously. The patients with BH(4) responsive PAH deficiency were treated with BH(4) tablets (10 - 20 mg/kg x d) under normal diet for 6 to 7 days. Their blood phenylalanine concentration was checked.

RESULTS(1) The characteristic curve of phenylalanine level was observed in 73 patients after BH(4) loading test. Twenty-two patients were diagnosed as classic phenylketonuria (PKU), 39 were moderate PKU and 12 were BH(4) deficiency. (2) Twenty-two (56.4%) of 39 moderate PKU patients were found to be responsive to BH(4) and the blood phenylalanine was decreased by at least 30%. (3) Six patients with BH(4) responsive PAH deficiency were treated with BH(4) for 6 to 7 days, 4 patients had a normal phenylalanine concentration after 10 mg/kg BH(4) supplement, while other 2 patients needed a treatment of BH(4) at 20 mg/kg.

CONCLUSIONSome patients with moderate PKU caused by phenylalanine hydroxylase deficiency were responsive to BH(4). Their blood phenylalanine significantly decreased after oral BH(4) loading. The BH(4) loading test is an effective diagnostic method to detect BH(4) sensitivity in PKU patients. BH(4) responsive PAH deficiency patient could be treated with BH(4) to replace low-phenylalanine diet treatment totally or partially, which may provide an optional treatment for the disease and improve the quality of life of the patients.

Biopterin ; analogs & derivatives ; deficiency ; therapeutic use ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Phenylalanine Hydroxylase ; deficiency ; Phenylketonurias ; diagnosis ; drug therapy

OBJECTIVETo perform tetrahydrobiopterin (BH(4)) loading test and to further understand its usefulness in differential diagnosis among hyperphenylalaninemia(HPA) patients.

METHODSBH(4) loading test was carried out in 73 HPA patients, including the positive cases unveiled by neonatal screening and the clinically suspected cases. These patients, 47 males and 26 females, were at a mean age of 1.93 months. BH(4) (20 mg/kg) loading test was performed in all patients, and a combined phenylalanine (Phe)(100 mg/kg) and BH(4) loading test was performed among the patient who had a basic blood Phe concentration less than 600 micro mol/L. The urine pterine profile analysis and the dihydropteridine reductase activity in dry blood filter spot were tested simultaneously.

RESULTSDuring BH(4) loading test or combined Phe and BH(4) loading test, the patients with classic phenylketonuria showed no response to BH(4), the patients with moderate HPA caused by Phe hydroxylase deficiency decreased 32.8% of blood Phe level and the patients with BH(4) deficiency showed a prompt reduction in blood Phe level and it decreased to normal level at 4 h and lasted until 24 h. Twenty-two cases were diagnosed as classic phenylketonuria, 39 were moderate phenylketonuria and 12 were BH(4) deficiency.

CONCLUSIONHyperphenylalaninemia may be caused by deficiency of Phe hydroxylase or by deficiency of co-factor BH(4). Early diagnosis is important. BH(4) loading test is a safe and fast test in vivo. It is sensitive, easy-to-do, and is highly useful in differential diagnosis for suspected cases of HPA.

Biopterin ; analogs & derivatives ; blood ; Diagnosis, Differential ; Dihydropteridine Reductase ; blood ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Mass Screening ; methods ; Phenylalanine ; blood ; Phenylalanine Hydroxylase ; deficiency ; genetics ; Phenylketonurias ; blood ; diagnosis ; genetics ; Sensitivity and Specificity

Biopterin ; analogs & derivatives ; deficiency ; genetics ; Child ; Consensus ; Diagnosis, Differential ; Humans ; Infant ; Infant, Newborn ; Neonatal Screening ; methods ; Phenylalanine ; blood ; Phenylalanine Hydroxylase ; deficiency ; genetics ; Phenylketonurias ; classification ; diagnosis ; therapy ; Practice Guidelines as Topic ; Severity of Illness Index ; Tyrosine ; blood

Biopterin ; analogs & derivatives ; deficiency ; genetics ; Child ; Consensus ; Diagnosis, Differential ; Humans ; Infant ; Infant, Newborn ; Neonatal Screening ; Phenylalanine ; blood ; Phenylalanine Hydroxylase ; deficiency ; genetics ; Phenylketonurias ; diagnosis ; etiology ; therapy ; Practice Guidelines as Topic ; Societies, Medical

Animals ; Blood Glucose ; drug effects ; Crystallization ; Cyclohexanes ; chemistry ; pharmacology ; Female ; Hyperglycemia ; blood ; Hypoglycemic Agents ; pharmacology ; Male ; Mice ; Mice, Inbred ICR ; Phenylalanine ; analogs & derivatives ; chemistry ; pharmacology ; X-Ray Diffraction

OBJECTIVETo analyze characteristics of different hyperphenylalaninemia (HPA) and to discuss the clinical difference between southern and northern Chinese patients with tetrahydrobiopterin (BH4) responsive phenylalanine hydroxylase (PAH) deficiency.

METHODS(1)BH4 (20 mg/kg) loading test was performed in all 108 HPA patients. These patients, 63 males and 45 females, were at a mean age of 7.05 months. A combined phenylalanine (Phe) and BH4 loading test was carried out in the patients who had a basic blood Phe concentration less than 600 micromol/L. The urine pterine profile analysis and the dihydropteridine reductase (DHPR) activity in dry blood filter spot were analyzed simultaneously. (2)BH4 responsive patients were divided to southern and northern groups by their parent's native place and geographic boundary determined by Changjiang River. The change of Phe concentration after BH4 loading test was compared between the two groups.

RESULTS(1)Among the 108 HPA cases, 36 patients (33.3%) were BH4 responsive PAH deficiency, 49 (45.4%) were non-BH4 no responsive phenylketonuria (PKU)and 23(21.3%)were BH4 deficiency (BH4D). The Phe concentration of patients with BH4 responsive PAH deficiency decreased by 49.24% and 65.35% at 8 h and 24 h after oral BH4, 23 in southern group and 13 in northern group among 36 patients. (2)The mean Phe concentration at 24 h after loading test in southern and northern groups were (217.02+/-189.03) micromol/L and 458.75+/-342.54 micromol/L respectively (P<0.05), although the decrease percent of plasma Phe concentration at 2 h, 4 h, 8 h, 24 h was no distinct difference between southern and northern groups (P>0.05).

CONCLUSIONMost of mild and moderate HPA patients affected by PAH deficiency show plasma Phe concentration decrease >30% in 24 h after oral BH4 20 mg/kg, few are classic PKU. The responsiveness to BH4 is no difference between southern and northern Chinese patients with BH4 responsive PAH deficiency according to the decrease percent of plasma Phe concentration, although the Phe concentration is lower in southern patients than that in northern patients.

Biopterin ; analogs & derivatives ; pharmacology ; therapeutic use ; Child, Preschool ; China ; Dihydropteridine Reductase ; blood ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Phenylalanine ; blood ; Phenylketonurias ; blood ; drug therapy ; Time Factors

Nitric oxide has emerged as a key signaling molecule in plants recently. The role of nitric oxide in elicitor-induced defense responses of plants has been extensively investigated. In this work, sodium nitroprusside was utilized as the donor of nitric oxide to investigate the effects of exogenous nitric oxide on hypericin production and cell growth of suspension cell cultures of Hypericum perforatum L.. Compared with the untreated Hypericum perforatum L. suspension cells, external application of 0.5 and 15.0 mmol/L sodium nitroprusside induced 1.4 and 0.5-fold dry cell weight, and 0.9 and 2.1-fold hypericin content respectively. The results showed that low concentration of sodium nitroprusside promoted the growth of Hypericum perforatum L. suspension cells, while high concentration of sodium nitroprusside enhanced hypericin biosynthesis in Hypericum perforatum L. suspension cells. The maximum hypericin production was achieved by adding 0.5 mmol/L and 15.0 mmol/L sodium nitroprusside to the culture at day 0 and day 14 respectively, increasing the total hypericin yield by nearly 3.2-fold. The effects of sodium nitroprusside on hypericin content and growth of Hypericum perforatum L. suspension cells were abolished by nitric oxide specific scavenger 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, which indicated that the effects of the application of sodium nitroprusside were caused by nitric oxide released from sodium nitroprusside rather than sodium nitroprusside itself. The results also showed that 15.0 mmol/L sodium nitroprusside stimulated the activities of phenylalanine ammonia-lyase (PAL), one of the key enzymes of phenylpropanoid pathway, in suspension cells of Hypericum perforatum L., which suggested that the synthetic pathway of hypericin might be activated by NO through triggering the defense responses of Hypericum perforatum L. suspension cells.
Cells, Cultured ; Hypericum ; cytology ; drug effects ; metabolism ; Nitric Oxide ; metabolism ; Nitroprusside ; pharmacology ; Perylene ; analogs & derivatives ; metabolism ; Phenylalanine Ammonia-Lyase ; metabolism ; Plant Growth Regulators ; biosynthesis

OBJECTIVETo study the expression of bradykinin and its receptors B1R and B2R in the kidney immune injury in trichloroethylene-sensitized mouse and discuss the pathogenesis of Dermatitis Medicamentosa-like of TCE (ODMLT).

METHODSOn the first days, intradermal injection by 50% TCE and the amount of FCA mixture 100 µl for initial sensitization; on 4, 7, 10 days, painted abdominal skin by 100 µl 50% TCE for three sensitization, on 17, 19 days, painted on the back skin by 100 µl 30% TCE for initial excitation and the last challenge; 24 h before each challenge, PKSI-527+TCE group received intraperitoneal injection by inhibitor PKSI-527 (50 mg/kg); solvent control group treat without TCE and sensitization and excitation reagent the same proportion of olive oil and acetone mixture, blank control group without any treatment. Before killing the mouse, renal weight and body weight were recorded. The renals and plasma were separated at 24 h, 48 h, 72 h and 7 d after the last challenge and observed pathological of the renals. Expression of B1R and B2R in renal were examined by immunofluorescence technique. Plasma were examined by ELISA for BK.

RESULTSThe renal pathological examination revealed the apparent damage of TCE sensitized mice which compared to solvent control group showed obvious cellular infiltration, vacuolar degeneration of renal tubular epithelial cells. The renal damage of PKSI-527+TCE-sensitized groups which compared to the corresponding point of TCE-sensitized groups showed significantly reduced. The expression of BK in 24 h, 48 h and 72 h TCE-sensitized groups were significant higher than solvent control group and related TCE non-sensitized groups (P < 0.05) and 72 h point compared to the corresponding point of PKSI-527+TCE group was also increased, the difference was statistically significant (P < 0.05). The expression levels of B1R and B2R in the kidney in 24 h, 48 h, 72 h and 7 d TCE-sensitized groups were obviously higher than solvent control group and related TCE non-sensitized groups. The expression levels of B1R and B2R in the kidney in the four point of PKSI-527+TCE sensitized group were relatively lower than the corresponding point of TCE sensitized group.

CONCLUSIONKKS activation may involved in the renal immune injury of trichloroethylene-sensitized mouse and the expression change of bradykinin and its receptors B1R and B2R which may play an important role in the process.

Administration, Cutaneous ; Animals ; Bradykinin ; metabolism ; Kidney ; drug effects ; metabolism ; pathology ; Mice ; Phenylalanine ; analogs & derivatives ; Receptor, Bradykinin B1 ; metabolism ; Receptor, Bradykinin B2 ; metabolism ; Solvents ; Tranexamic Acid ; analogs & derivatives ; Trichloroethylene ; toxicity