For the minimized phase transtorming risk, the most stable polymorph is generally considered as the desirable solid form for pharmaceutical applications. However, occasionally, the stable form may have some shortcomings such as low solubility, dissolution rate and bioavailability, etc. In that case, the metastable form which is kinetically stable at room or lower temperature could be selected. Using metastable form may result in polymorph transformation in pharmaceutical manufacture and storage. Hence, the knowledge of the transformation between solid forms is essential to the development of the drug materials. In this paper, we will review the recent studies in the area of crystal conversion of polymorphs and hydrates, to illustrate some cases to introduce the types, conditions and mechanisms of the crystalline solid transformation.

For the minimized phase transtorming risk, the most stable polymorph is generally considered as the desirable solid form for pharmaceutical applications. However, occasionally, the stable form may have some shortcomings such as low solubility, dissolution rate and bioavailability, etc. In that case, the metastable form which is kinetically stable at room or lower temperature could be selected. Using metastable form may result in polymorph transformation in pharmaceutical manufacture and storage. Hence, the knowledge of the transformation between solid forms is essential to the development of the drug materials. In this paper, we will review the recent studies in the area of crystal conversion of polymorphs and hydrates, to illustrate some cases to introduce the types, conditions and mechanisms of the crystalline solid transformation.
Biological Availability ; Chemistry, Pharmaceutical ; methods ; Crystallization ; Drug Stability ; Kinetics ; Pharmaceutical Preparations ; chemistry ; Solubility

AIM:To study the effect of integrin β1 on multidrug resistance in gastric cancer and its possible mechanisms .METHODS:The expression of integrin β1 at mRNA and protein levels in the SGC-7901 cells and SGC-7901/DDP cells was determined by qPCR and Western blot .The expression of integrin β1 in the SGC-7901/DDP cells was silenced by antisense oligodeoxynucleotide .The cell viability was detected by the CCK-8 assay, the cell apoptosis were ana-lyzed by flow cytometry, and the protein levels of integrin β1, Bcl-2/Bax, cleaved caspase-3/caspase-3, cytochrome C ( Cyt-C) and p-AKT/AKT were determined by Western blot .RESULTS:The expression of integrin β1 at both mRNA and protein levels was significantly upregulated in SGC-7901/DDP cells.The expression of integrin β1 was increased in SGC-7901 cells treated with chemotherapeutic agents such as cisplatin , paclitaxel and 5-fluorouracil .Knockdown of integrin β1 induced apoptosis of SGC-7901/DDP cells with an increased sensitivity to the chemotherapeutic agents .Meanwhile , knock-down of integrin β1 downregulated the protein levels of Bcl-2/Bax, p-AKTSer473 and p-AKTThr308 , while promoted the release of Cyt-C and upregulated the protein level of cleaved caspase-3.CONCLUSION:Knockdown of integrin β1 increases the sensitivity of SGC-7901/DDP cells to the chemotherapeutic agents , and promotes the cell apoptosis via mitochondrial apop-tosis pathway .The mechanism may be related to the attenuation of AKT pathway by inhibiting phosphorylations of AKT at Ser473 and Thr308.

Objective To investigate the serum cystatin C (CysC) level and explore its relationship with cytokines and atherosclerosis (AS) in maintenance hemodialysis (MHD) patients.Methods A total of 110 stable MHD patients undergoing hemodialysis for at least six months and 60 healthy control people were enrolled in the study.Serum levels of CysC and high-sensitivity Creactive protein (hsCRP) were measured by immunoturbidimetry.The serum levels of total homocysteine (tHcy),IL-1β,IL-6 and TNF-α were determined by ELISA.Prevalence of atherosclerosis was detected by carotid ultrasonography.The relationship of CysC level and cardiac geometry incidence in MHD patients was analyzed by Logistic regression model.Results The serum CysC level was significantly higher in MHD patients as compared with healthy controls [(6.19±0.95) mg/L vs (0.76±0.21) mg/L,P＜0.01],and the serum levels of hsCRP,tHcy,IL-1β,IL-6,TNF-α were significantly higher in MHD patients than those in healthy control group (P＜0.05 or P＜0.01).The serum CysC level was higher in MHD patients with carotid artery atherosclerosis compared to patients without carotid artery atherosclerosis (P＜0.05).CysC was positively correlated with hsCRP,tHcy,IL-1β,IL-6,TNF-α respectively (P＜0.05 or P＜O.01),and was positively correlated with carotid intimal medial thickness (IMT) and AS.Besides,a negative correlation was found between the serum CysC level and the serum albumin level (P＜0.05),while CysC was positively correlated with dialysis duration,systolic pressure and iPTH (P ＜0.05).Conclusion Serum CysC level is significantly higher in MHD patients and is correlated with hsCRP,tHcy,IL-1β,IL-6,TNF-α as well as carotid artery atherosclerosis,which indicates that CysC is an independent risk factor of AS in MHD patients.

Objective To construct the recombinant plasmid of fusion protein containing respiratory syncytial virus (RSV) cytotoxicity T lymphocyte (CTL) epitope M2:81-95 and heat shock protein (HSP) 70L1, and to investigate its immunogenicity after prokaryotic expression. Methods HSP70L1 gone was cloned from SMMC7721 cells. The M2:81-95 gene fragment was amplified by polymerase chain reaction (PCR) method. Plasmid pET-HSP70L1-M2 : 81-95 (pET-HSP70L1-M2) was constructed, identified and transferred into E. coli BL21 (DE3). Expression of HSP70L1-M2 : 81-95(HSP70L1-M2) was induced by isopropy-β-D-thiogalaetosidc (IPTG). The expressed protein was purified by affinity chromatography and renatured by gradient dialysis. The BALB/c mice were immunized with this fusion protein. IgG antibodies and the subtypes were detected by enzyme-linked immunosorbent assay (ELISA), and CTL responses were determined by methyl thiazolyl tetrazolium (MTT). Results The recombinant plasmid pET-HSP70L1-M2 was successfully constructed. The fusion protein HSP70L1-M2 was expressed in E. coll. The purified protein induced strong RSV-and CTL epitope-specific CTL responses and high titer of protein specific lgG antibody 4.87±0.35. The subtypes were IgG1 (5.53±0.28) and lgG2a (4.40±0.21) and IgG1/ IgG2a ratio was balanced. The titers of lgG, IgG1 and IgG2a in PBS control group were 0.33±0.17, 0.51±0.21 and 0, respectively, which werc significantly lower than those in immunized group (t = 3.512, 3.681, 5.856; P<0.05). Conclusions The recombinant plasmid pET-HSP70L1-M2 is successfully constructed and the fusion protein is expressed and purified. HSP70L1-M2 induced strong RSV-and CTL epitope-specific CTL responses and mixed T helper cell (Th)1/Th2 response in BALB/c mice.

Objective To explore the role of cytokines on the pathogenesis of hypoxic-ischemic en-cephalopathy (HIE). Method The levels of peripheral blood interleukin (IL)-6, IL-8, tumor necrosis factor-alpha (TNF-α) in 40 HIE and 40 healthy neonates were detected at the 1st, 3rd and 7th day after birth by using radioimmunoassay. Results Compared with healthy neonates, at the 1 st, 3rd after birth, the level of peripheral blood IL-6 was decreased [(52.3±24.5)ng/L vs (80.1±28.6)ng/L and (56.9±28.5) ng/L vs (78.6±28.9)ng/L, respoctively], but IL-15 and TNF-α were increased [IL-8:(0.68±0.23)ng/L vs (0.47±0.13)ng/L and (0.63±0.22)ng/L vs (0.40±0.16)ng/L, TNF-α: (1.17±0.30)ng/L vs (0.91± 0.30) ng/L and (1.14±0.29)ng/L vs (0.96±0.34)ng/L]in HIE infants. Conclusion The changes of plas-ma levels of IL-6, IL-8 and TNF-α in neonatal HIE possibly play an important role in the pathophysiologic mechanisms of HIE.

Objective To investigate the effect of L-carnitine on pathological changes of myocardium and the underlying mechanism in chronic renal failure rats (CRF). Methods A total of 55 male SD rats were randomly divided into sham group (n=10),model group (n=15),low dose (300 mg/kg),medium dose (600 mg/kg) and high dose (900 mg/kg) L-carnitine group(n=10,each).5/6 subtotal nephrectomy was performed in these rats without sham group.One week after the operation,normal saline or corresponding dose L-carnitine were intragastrically administrated to sham and model group or L-carnitine groups for 17 weeks.Transthoracic echocardiography,mean arterial pressure (MAP),heart rate (HR) and heart weight/body weight were assessed.Moreover,24h urine protein,renal function,SOD,MDA,IL-6,ATP,ADP were measured at the end of the study.Additionally,pathological changes in myocardium were detected by light microscope and transmission electron microscope. Results (1) ATP (μmol/g·wt)in L-carnitine groups (2.35±0.24,3.59±0.28,3.78±0.25) was significantly higher than that in model group (1.61±0.12) (all P＜0.01).(2) Thickness of posterior wall of left ventricle (mm) in high dose L-carnitine group was thinner than that in model group (3.74±0.23 vs 4.18±0.48,P＜0.05). (3) The ratios of heart weight to body weight in both medium dose and high dose L-carnitine groups (3.92±0.27,3.65±0.2) were significantly lower compared to model group (3.99±0.27) (all P＜0.01). (4) Under light microscopy,disarrangement and hypertrophy of cardiac myocytes,increased myocardial fibrosis were observed in model group, while these changes and the pathological scores were significantly improved in both medium dose and high dose L-carnitine groups (7.14±1.07,6.13±0.99),as compared with model group (9.88±1.13) (all P＜0.01).Under electron microscopy,typical changes in cardiac hypertrophy were observed,including dissolution of myocardial fibers,increasing and swelling of mitochondria,membrane rupture as well as matrix increase in model group,while these changes were ameliorated by L-carnitine in a dose-dependent manner. (5) Seventeen weeks after the treatment,both IL-6 and MDA were decreased in all L-carnitine-treated groups than those in model group [IL-6 (ng/L):261.86±13.18,240.12±18.7,233.34±36.88 vs 596.64±81.41; MDA (nmol/L):15.23±2.01,12.41±0.6.10.97±1.9 vs 21.84±2.71).Whereas,SOD (U/ml) were increased in L-carnitine-treated groups (51.2±6.11,58.51±5.52,60.63±6.94) than that in model group(32.01 ±5.69 )(all P＜0.05).(6) No significant differences of systolic,diastolic blood pressure or MAP were found among groups. Conclusion L-carnitine can improve energy metabolism,micro-inflammation and oxidative stress in myocardium of CRF rats,which may be associated with the amelioration of cardiac hypertrophy and fibrosis.

Objective To investigate the serum level of free fatty acid (FFA) and explore its relationship with cytokines and atherosclerosis (AS) in chronic kidney disease (CKD).Methods The serum level of FFA was determined with enzymatic colorimetry.IL-1 β, IL-6 and TNFα were determined with ELISA.High-sensitivity C-reactive protein (hsCRP) was measured with immunoturbidimetry.Prevalence of atherosclerosis was detected with carotid ultrasonography.We evaluated the relationship between serum levels of FFA and IL-1β,IL-6, TNFα, hsCRP as well as the renal function in 130 adult patients with CKD, stratified according to the GFR ( based on the National Kidney Foundation/Kidney Dialysis Outcomes Quality Initiatives) and in 58 hemodialytic (HD) patients.The relationship between FFA level and cardiac geometry incidence in CKD patients was analyzed with logistic regression model.Results The serum level of FFA was significantly higher in CKD patients as compared with that in the healthy controls [(492.63 ± 143.59)vs (302.65 ± 142.18) μ mol/L, P ＜ 0.01], even in the early stage of CKD.The level of FFA increased with the progression of renal dysfunction.In the non-dialytic CKD group, the level of FFA was negatively related to GFR and positively related to the proteinuria (P ＜ 0.05), while in the HD group, it was positively correlated with dialysis duration ( P ＜ 0.05 ).The serum levels of FFA were higher in CKD patients with carotid artery atherosclerosis than those in patients without ( P ＜ 0.05 or ＜ 0.01 ).However, in both groups with impairment of renal function, the levels of FFA were positively correlated with hsCRP, IL-1 β, IL-6,TNFα and TG( all P ＜ 0.05 ).A positive correlation between the level of FFA and the clinical manifestations such as carotid intimal medial thickness (IMT) and AS was also found.A negative correlation was found between the level of FFA and the serum level of albumin and GFR( P ＜ 0.05).Conclusion Serum levels of FFA are significantly higher either in non-dialytic CKD or in HD patients and it is related with hsCRP, IL-1 β, IL-6, TNFα as well as carotid artery atherosclerosis, indicating that FFA is an independent risk factor of AS in CKD.

Objective To investigate the effects of levocarnitine combined with urimetazidine on left ventricular remodeling in maintenance hemodialysis(MHD)patients.Methods All of 86 MHD patients and 40 healthy volunteers(health control group)were involved in the study.all of 86 MHD patients were randomly divided into two groups,disease treatment group(46 cases)and disease control group(40 cases),who had undergone hemodialysis for at least 3 months before the study and were in a stable clinical status without signs of infection or disease activity.In disease treatment group,1.0 g of levocarnitine was infused at the end of each dialysis treatment and 20 mg of trimetazidine was taken orally 3 times each day for 6 months,while the parameters for free fatty acid(FFA),free carnitine(FC),inflammation and oxidative stress were studied before and after the treatmenL In disease control group these two drugs were not used.The left ventricular end-diastolic diameter(LVDd),left ventricuhr end-systolic diameter(LVDs),left atrial diameter (LAD),left ventricular posterior wall thickness(LVPWT),interventricular septal thickness(IVST)and left ventricular ejection fraction(LVEF)were detected by ultrasonic cardiography.Results Before treatment,the serum levels of FFA,high-sensitivity C-reactive protein(hs-CRP),intedeukin(IL)-1β,IL-6,tumor necrosis factor(TNF)-αand malondialdehyde(MDA)were higher in disease treatment group and disease control group than those in health control group(P<0.05 or<0.01),while the serum levels of FC,glutathione peroxidase(GSHPx)and superoxide dismutase(SOD)were lower in disease treatment group and disease control group than those in health control group(P<0.05 or<0.01).Compared with those before treatment,the serum levels of FFA,hs-CRP,IL-1β,IL-6,TNF-α,MDA were decreased(P<0.05 or<0.01),FC,GSHPx,SOD were increased(P<0.05 or<0101),the scores of LVDd,LAD,IVST,LVPWT,LVMI were also decreased significantly(P<0.05),while LVEF increased markedly after treatmem in disease treatment group(P<0.05).There were significant differences in all indexes between disease treatment group and disease control group(P<0.05 or<0.01).Conclusion Supplements of levocarnitine combined with trimetazidine in MHD patients appear to be associated with an improvement of left ventricular remodeling.

Administration, Oral ; Animals ; Mice ; Nanoparticles ; toxicity ; Particle Size ; Titanium ; toxicity ; Toxicity Tests, Acute