Directed differentiation of human induced pluripotent stem cells into midbrain / 南方医科大学学报

OBJECTIVE@#To establish an efficient protocol for directed differentiation of human induced pluripotent stem cells (hiPSCs) into functional midbrain dopaminergic progenitor cells (DAPs) in vitro.@*METHODS@#hiPSCs were induced to differentiate into DAPs in two developmental stages. In the first stage (the first 13 days), hiPSCs were induced into intermediate cells morphologically similar to primitive neuroepithelial cells (NECs) in neural induction medium containing a combination of small molecule compounds. In the second stage, the intermediate cells were further induced in neural differentiation medium until day 28 to obtain DAPs. After CM-DiI staining, the induced DAPs were stereotactically transplanted into the right medial forebrain bundle (MFB) of rat models of Parkinson's disease (PD). Eight weeks after transplantation, the motor behaviors of PD rats was evaluated. Immunofluorescence assay of brain sections of the rats was performed at 2 weeks after transplantation to observe the survival, migration and differentiation of the transplanted cells in the host brain microenvironment.@*RESULTS@#hiPSCs passaged stably on Matrigel showed a normal diploid karyotype, expressed the pluripotency markers OCT4, SOX2, and Nanog, and were positive for alkaline phosphatase. The primitive neuroepithelial cells obtained on day 13 formed dense cell colonies in the form of neural rosettes and expressed the neuroepithelial markers (SOX2, Nestin, and PAX6, 91.3%-92.8%). The DAPs on day 28 highly expressed the specific markers (TH, FOXA2, LMX1A and NURR1, 93.3-96.7%). In rat models of PD, the hiPSCs-DAPs survived and differentiated into TH+, FOXA2+ and Tuj1+ neurons at 2 weeks after transplantation. Eight weeks after transplantation, the motor function of PD rats was significantly improved as shown by water maze test (P < 0.0001) and apomorphine-induced rotation test (P < 0.0001) compared with rats receiving vehicle injection.@*CONCLUSION@#HiPSCs can be effectively induced to differentiate into DAPs capable of differentiating into functional neurons both in vivo and in vitro. In rat models of PD, the transplanted hiPSCs-DAPs can survive for more than 8 weeks in the MFB and differentiate into multiple functional neurocytes to ameliorate neurological deficits of the rats, suggesting the potential value of hiPSCs-DAPs transplantation for treatment of neurological diseases.

Effects of ring finger and tryptophan-aspartic acid 2 on dendritic spines and synapse formation in cerebral cortex neurons of mice / 南方医科大学学报

OBJECTIVE@#To clarify the functional effects of differential expression of ring finger and tryptophan-aspartic acid 2 (RFWD2) on dendritic development and formation of dendritic spines in cerebral cortex neurons of mice.@*METHODS@#Immunofluorescent staining was used to identify the location and global expression profile of RFWD2 in mouse brain and determine the co-localization of RFWD2 with the synaptic proteins in the cortical neurons. We also examined the effects of RFWD2 over-expression (RFWD2-Myc) and RFWD2 knockdown (RFWD2-shRNA) on dendritic development, dendritic spine formation and synaptic function in cultured cortical neurons.@*RESULTS@#RFWD2 is highly expressed in the cerebral cortex and hippocampus of mice, and its expression level was positively correlated with the development of cerebral cortex neurons and dendrites. RFWD2 expression was detected on the presynaptic membrane and postsynaptic membrane of the neurons, and its expression levels were positively correlated with the length, number of branches and complexity of the dendrites. In cultured cortical neurons, RFWD2 overexpression significantly lowered the expressions of the synaptic proteins synaptophysin (P < 0.01) and postsynapic density protein 95 (P < 0.01), while RFWD2 knockdown significantly increased their expressions (both P < 0.05). Compared with the control and RFWD2-overexpressing cells, the neurons with RFWD2 knockdown showed significantly reduced number of dendritic spines (both P < 0.05).@*CONCLUSION@#RFWD2 can regulate the expression of the synaptic proteins, the development of the dendrites, the formation of the dendritic spines and synaptic function in mouse cerebral cortex neurons through ubiquitination of Pea3 family members and c-Jun, which may serve as potential treatment targets for neurological diseases.

Epidemiological characteristics of 14 clusters and outbreaks of Norovirus infection in Nan an District of Chongqing in 2018 / 中国学校卫生

Objective@#To analyze of epidemiological and etiological characteristics of 14 norovirus clusters or outbreak in Nan an District, for comprehensive prevention and control measures for norovirus infections in the region.@*Methods@#Data were collected from the emergency public health event management information system of China Disease Prevention and Control Information System, and were analyzed by using descriptive epidemiological method.@*Results@#In 2018, 14 cases of norovirus infection clusters and outbreaks were reported in Nan an District, accounting for 63.64% of the total number of incidents in the region. A total of 268 cases were reported, with an average incidence of 2.19%; the outbreak occurred mainly in November(n=6); kindergartens reported the most outbreak(n=7), followed by primary schools(n=5); the median duration of the outbreak was 2.80 days; and 14 outbreaks were caused by the GII-type genome of norovirus, with the main transmission routes being human-to-hnuman transmission.@*Conclusion@#The prevalence of norovirus outbreaks tends to be higher in schools, it is necessary to strengthen the monitoring of vomiting and diarrhea symptoms in collective units such as schools, and efforts should be promoted for implementation of all levels of prevention and control measures in school.

Evaluation of 3D-printed oval root canal preparation by small field-of-view cone beam CT and computer-aided technique / 口腔疾病防治

Objective@# To evaluate the effect of 3D-printed oval root canal preparation by using small field-of-view cone beam CT (CBCT) combined with computer-aided technologies.@*Methods@#An extracted tooth with a suitable single oval canal was selected by small field-of-view CBCT scanning. Three-dimensional (3D)-printed resin teeth were obtained based on the CBCT data after data conversion and processing. 50 general dentists were selected to prepare the oval root canal of the resin teeth with X-Gold rotary Ni-Ti instruments. Small field-of-view CBCT was applied to scan the oval root canals before and after preparation. Then, computer-aided technologies were used to calculate and compare these CBCT data, analyzing the effects of oval root canal cleaning as well as the root canal deviation by 3D reconstruction and rendering of the images.@*Results @#Among the 50 cases, the mean unprepared area of the oval root canal wall was（56.20 ± 11.91）% and the mean maximum deviation distance of the root canal was（0.140 ± 0.041）mm. There was no correlation between root canal cleanliness and deviation (r=0.18, P=0.212).@*Conclusion @# Combined with small field-of-view CBCT and computer-aided technology, we can effectively quantitatively evaluate the root canal preparation effect.

Influence of cow's milk protein allergy on the diagnosis of functional gastrointestinal diseases based on the Rome IV standard in infants and young children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the influence of cow's milk protein allergy (CMPA) on the diagnosis of functional gastrointestinal diseases (FGID) based on the Rome IV standard in infants and young children.</p><p><b>METHODS</b>A total of 84 children aged 1 month to 3 years who were diagnosed with CMPA were enrolled as the case group, and 84 infants and young children who underwent physical examination and had no CMPA were enrolled as the control group. The pediatricians specializing in gastroenterology asked parents using a questionnaire for the diagnosis of FGID based on the Rome IV standard to assess clinical symptoms and to diagnose FGID.</p><p><b>RESULTS</b>The case group had a significantly higher incidence rate of a family history of allergies than the control group (P<0.05). In the case group, 38 (45%) met the Rome IV standard for the diagnosis of FGID, while in the control group, 13 (15%) met this standard (P<0.05). According to the Rome IV standard for FGID, the case group had significantly higher diagnostic rates of reflex, functional diarrhea, difficult defecation, and functional constipation than the control group (P<0.05). The children who were diagnosed with FIGD in the control group were given conventional treatment, and those in the case group were asked to avoid the intake of cow's milk protein in addition to the conventional treatment. After 3 months of treatment, the case group had a significantly higher response rate to the treatment than the control group (P<0.05).</p><p><b>CONCLUSIONS</b>In infants and young children, CMPA has great influence on the diagnosis of FGID based on the Rome IV standard. The possibility of CMPA should be considered during the diagnosis of FGID.</p>

Rapid and sensitive detection of Bordetella bronchiseptica by loop-mediated isothermal amplification (LAMP)

Bordetella bronchiseptica causes acute and chronic respiratory infections in diverse animal species and occasionally in humans. In this study, we described the establishment of a simple, sensitive and cost-efficient loop-mediated isothermal amplification (LAMP) assay for the detection of B. bronchiseptica. A set of primers towards a 235 bp region within the flagellum gene of B. bronchiseptica was designed with online software.. The specificity of the LAMP assay was examined by using 6 porcine pathogens and 100 nasal swabs collected from healthy pigs and suspect infected pigs. The results indicated that positive reactions were confirmed for all B. bronchiseptica and no cross-reactivity was observed from other non-B. bronchiseptica. In sensitivity evaluations, the technique successfully detected a serial dilutions of extracted B. bronchiseptica DNA with a detection limit of 9 copies, which was 10 times more sensitive than that of PCR. Compared with conventional PCR, the higher sensitivity of LAMP method and no need for the complex instrumentation make this LAMP assay a promising alternative for the diagnosis of B. bronchiseptica in rural areas and developing countries where there lacks of complex laboratory services.

Development and evaluation of a loop-mediated isothermal amplification (LAMP) assay for rapid detection of Actinobacillus pleuropneumoniae based the dsbE-like gene

This paper reports on the development and validation of a loop-mediated isothermal amplification assay (LAMP) for the rapid and specific detection of Actinobacillus pleuropneumoniae (A. pleuropneumoniae). A set of six primers were designed derived from the dsbE-like gene of A.pleuropneumoniae and validate the assay using 9 A. pleuropneumoniae reference/field strains, 132 clinical isolates and 9 other pathogens. The results indicated that positive reactions were confirmed for all A. pleuropneumoniae strains and specimens by LAMP at 63ºC for 60 min and no cross-reactivity were observed from other non-A.pleuropneumoniae including Haemophilus parasuis, Escherichia coli, Pasteurella multocida, Bordetella bronchiseptica, Streptococcus suis, Salmonella enterica, Staphylococcus, porcine reproductive and respiratory syndrome virus (PRRSV), and Pseudorabies virus. The detection limit of the conventional PCR was 10² CFU per PCR test tube, while that of the LAMP was 5 copies per tube. Therefore, the sensitivity of LAMP was higher than that of PCR. Moreover, the LAMP assay provided a rapid yet simple test of A. pleuropneumoniae suitable for laboratory diagnosis and pen-side detection due to ease of operation and the requirement of only a regular water bath or heat block for the reaction.

Clinicopathological characteristics of malignant transformation in 85 cases of oral leukoplakia / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the histological features of oral leukoplakia which underwent malignant transformation and its correlation with the clinical manifestation.</p><p><b>METHODS</b>A total of 1832 cases of oral leukoplakia were reviewed and the clinicopathological characteristics of malignant transformation were analyzed.</p><p><b>RESULTS</b>Malignant transformation occurred in 85 cases (4.6%) of the 1832 cases. Thirty cases (2.1%) of 1404 cases with simple epithelial hyperplasia had malignant transformation. Fifty-five cases (12.9%) in 428 cases with epithelial dysplasia were transformed to malignancy, especially in the cases with moderate or severe dysplasia, in which the ratio of malignant transformation was higher than in the cases with simple epithelial hyperplasia (P < 0.005). Clinical parameters associated with an increased risk of malignant transformation were female gender and epithelial dysplasia was more often seen in non-homogenous leukoplakias than in homogenous (P < 0.005).</p><p><b>CONCLUSIONS</b>Non-dysplastic leukoplakia may become malignant. Epithelial dysplasia was associated with an increased risk of malignant transformation. Leukoplakia in female may be at a higher risk for malignant transformation.</p>

A community-based sero-epidemiological study of hepatitis B infection in Lianyungang, China, 2010

Introduction:The 2010 targets of the China Hepatitis B Prevention Programme were a prevalence of hepatitis B surface antigen (HBsAg) less than 1.0% for children less than five years old and less than 6.0% for the total population. This survey assessed the prevalence of Hepatitis B infection in Lianyungang, Jiangsu province, China in 2009–2010.Methods:Multistage sampling was used with 2372 subjects among 17 selected villages. Blood specimen collection and testing by enzyme-linked immunosorbnet assay (ELISA) were completed using the following markers for hepatitis infection: HBsAg and antibody to HBsAg (anti-HBs); hepatitis B e antigen (HBeAg) and antibody to HBeAg (anti-HBe); and hepatitis B core antibody (total anti-HBc). The data were analysed with Epi Info, version 3.3.2.Results:The prevalence of HBsAg was 2.4% (95% Confidence Interval [CI]: 1.8–3.0; Adjusted Prevalence [AP] 2.9%); anti-HBs prevalence was 51.1% (95% CI: 49.1–53.1; AP 49.2%) and total anti-HBc prevalence was 41.7% (95% CI: 39.8–43.7; AP 45.5%). The prevalence of HBsAg and total anti-HBc positivity increased from young to older age groups, yet the prevalence of anti-HBs positivity decreased from young to older age groups (PP= 0.108 and 0.089), but females had a higher prevalence than males for total anti-HBc positivity (P< 0.001). Discussion: This survey showed that in 2010 the prevalence of HBsAg among children aged less than five years was lower than the national target of 1.0% and that the prevalence of HBsAg for the total population was lower than the national target of 6.0%.

Expression of integrin-linked kinase in oral squamous cell cancinoma and its significance / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression patterns of integrin-linked kinase (ILK) in oral squamous cell carcinoma (OSCC).</p><p><b>METHODS</b>The expression of ILK in 170 OSCC cases was examined by immunohistochemistry and periodic acid-schiff histochemistry.</p><p><b>RESULTS</b>ILK immunoreactivity occurred in cancer cells and(or) stroma encircling the malignant tissue. Along with the deteriorated histopathologic grade of oral cancer, there was stepwise aberration exhibiting from ILK-negative, to ILK-positive in epithelia, to ILK-positive in both epithelia and stroma, and to ILK-positive in stroma. Through non-parameter test, in both lymphatic invasion [ILK-positive in stroma in well-differentiated, moderately-differentiated and poorly-differentiated is 2% (1/50), 18% (6/33) and 64% (18/28), respectively] and non-lymphatic invasion group [ILK-positive in stroma in well-differentiated, moderately-differentiated and poorly-differentiated is 16% (4/25), 9/18 and 10/16, respectively), the expression patterns of ILK exhibited significant correlations with histopathology (F = 17.742, P < 0.001, F = 4.394, P = 0.017). ILK expression between lymphatic metastasis and non-lymphatic metastasis group was significantly different (χ(2) = 14.418, P = 0.002).</p><p><b>CONCLUSIONS</b>ILK inclines to express in stroma during the OSCC progress.</p>

Expression of integrin-linked kinase in oral leukoplakia and early invasive carcinoma / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the transmutation and significance of integrin-linked kinase (ILK) in oral leukoplakia and early invasive squamous cell carcinoma.</p><p><b>METHODS</b>Immunohistochemistry accompanied with periodic acid Schiff reaction (PAS) histochemistry was applied to detect the expression of ILK in 19 normal oral mucosa, 43 simple hyperplasia, 84 epithelial dysplasia, 54 early invasive carcinoma.</p><p><b>RESULTS</b>Among the oral leukoplakia and early invasive squamous cell carcinoma, dramatic positive expression of ILK was found in 163/181 (90%), but was negative in normal mucosa. ILK staining in stroma exhibited a significantly direct correlation with the exacerbated epithelial dysplasia (chi(2) = 41.585, P < 0.001). Along with the oral carcinogenesis, there was an obvious tendency of change-overed ILK staining from superfacial to the basal orientation, the stratum basale diverted into positive, and compared with scattering in cytoplasm, the location of ILK was prone to cytomembrane in epithelium. In severe dysplasia and carcinoma in situ, there was a positive correlation between the basal layer and stroma expression of ILK (P = 0.029). It was not only a weaker tincture of ILK in cancer nest than lesional epithelia, but also an augmentation of stroma staining in early invasive squamous cell carcinoma [76% (41/54)] by contrast with severe dysplasia [45% (18/40)].</p><p><b>CONCLUSIONS</b>The pivotal role of ILK in the regulation of oral carcinogenesis is considerable, however, the precise mechanisms through which ILK affects cellular processes remain to be fully characterized.</p>

Podoplanin expression in oral squamous cell carcinoma and leukoplakia and its correlation with lymph vessels density / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of Podoplanin in lesional epithelia of oral leukoplakia and squamous cell carcinoma and its correlation with lymph vessels density.</p><p><b>METHODS</b>The expression of Podoplanin in 40 cases of oral leukoplakia, 27 cases of early stage of squamous cell carcinoma and 32 cases of infiltrated stage of squamous cell carcinoma was examined by immunohistochemistry. Meanwhile, the correlation between podoplanin expression in lesional epithelia and its corresponding lymph vessels density was also analysed.</p><p><b>RESULTS</b>Podoplanin expression in epithelia was increased with the exacerbated epithelial proliferation. High expression of Podoplanin in lesional epithelia accounted for 45% in oral leukoplakia, 81% and 78% in early and infiltrated stage of squamous cell carcinoma respectively. Moreover, the lymph vessels density was also increased with the enhanced expression of Podoplanin in oral leukoplakia and early stage of squamous cell carcinoma (P < 0.05). Podoplanin expression in infiltrated stage of squamous cell carcinoma was positively correlated with the lymph vessels density (P < 0.05).</p><p><b>CONCLUSIONS</b>Podoplanin expression in different proliferative oral epithelia may be related to oral carcinogenesis, invasion and metastasis.</p>

Effects of astragalus injection on renal function in patients after cardiac valve replacement with cardiopulmonary bypass / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effects of Astragalus Injection (AI) on renal function in patients after cardiac valve replacement with cardiopulmonary bypass (CPB).</p><p><b>METHODS</b>Forty patients scheduled to receive cardiac valve replacement with CPB were randomly assigned to 2 groups equally, the control group and the AI group. Patients in the AI group were administered with AI 40 mL before anesthesia by diluting it in 250 mL 5% glucose solution via intravenous dripping, 20 mL by adding it into the priming solution before CPB and 40 mL once a day diluted as before via intravenous dripping at the foremost 5 successive days after operation. For patients in the control group, equal volume of Ringer's Liquid was given instead of AI. Peripheral blood sample and urine were collected at various time points: before anesthesia (T0), the 1st (T1), 3rd (T3), 5th (T5) and 7th day (T7) after operation, for determining blood levels of urea nitrogen (BUN), creatinine (Cr) and beta2-microglobulin (beta2-MG), as well as urinary levels of beta2-MG, microalbumin (m-Alb) and N-acetyl-D-glucosaminidase (NAG).</p><p><b>RESULTS</b>As compared with those at T0, in the control group, BUN, Cr at T1 and T3, serum beta2-MG at T3, urinary beta2-MG m-Alb and NAG at T1-T7 were significantly higher, while in the AI group, urinary m-Alb, NAG at T1-5 n and urinary beta2-MG at T1-7 were higher (P < 0.05). As compared with those in the control group, serum BUN at T1-3., Cr and blood beta2-MG at T3, urinary beta2-MG, m-Alb and NAG at T1-7 were lower (P < 0.05) in the AI group.</p><p><b>CONCLUSION</b>CPB could induce renal failure, and applying AI at the perioperative stage can protect renal function to some certain extent.</p>

Clinical degree of the superior mesenteric vein involvement with the surgery in the pancreas uncinate process carcinoma / 中华外科杂志

<p><b>OBJECTIVE</b>To create the clinical degree of the superior mesenteric vein (SMV) involvement in pancreas uncinate process carcinoma (PUPC) and its clinical significance to be discussed.</p><p><b>METHODS</b>According to the contiguous relationship between the SMV and the PUPC, the clinical degree of SMV involvement in PUPC are as followings four grades, 1 grade, the grade of clear boundary. 2 grade, the grade of fuzzy boundary. 3 grade, the grade of dissolved boundary. 4 grade, the grade of SMV infringed. The coherence between the type under the CT scan (Tx) and the type under the inoperative judgement (Sx) were analyzed with Kappa-test.</p><p><b>RESULTS</b>There is a significant difference between the grade of SMV involvement and the surgery. The resection rate is 100% in 1st grade, 97.4% in 2nd grade, 65.8% in 3rd grade and 21.7% in 4th grade. There is coherent in the degree judgement between the CT scan and the inoperative inspection (U = 15.96, P < 0.01).</p><p><b>CONCLUSIONS</b>There is clinical significance to establish the degree of SMV involvement in PUPC. It is helpful for clinician to accurately know its anatomic characteristic and decide more reasonable surgical strategy.</p>

A clinical study on effect of Shenqi Fuzheng injection (参芪扶正注射液) on preservation of renal function in patients after cardiac surgery and cardiopulmonary bypass / 中国中西医结合急救杂志

Objective To study the effect of Shenqi Fuzheng injection (SQFZI,参芪扶正注射液) on renal function in patients after cardiac surgery and cardiopulmonary bypass (CPB).Methods Forty patients ready for receiving CPB and cardiac surgery were randomly assigned to two groups,20 being in each group. Patients in the SQFZI group were administered of 250 ml SQFZI intravenously before anesthesia,125 ml SQFZI before CPB in CPB mechanical equipment,and 250 ml SQFZI once a day after operation for 3 days. Equal volume balanced solution was received in control group.Creatinine (Cr) in blood and Cr,microalbumin (m-Alb),?_2-microglobulin (?_2-MG) and N-acetylglucosaminidase (NAG) in urine were measured and endogeneous creatinine clearance (CCr) was calculated in 40 patients at the time points of before anesthesia, at the end of operation,and 1,3 and 5 days after operation.Results Urinary levels of m-Alb,?_2-MG and NAG were increased significantly after CPB in both groups at different time points at the end of and after the operation (all P0.05).Conclusion CPB has a deteriorating effect on renal function,and the application of SQFZI in peri-operational period has a protective effect on renal function in patients who undergo CPB.

The Preventive Effect of Dexrazoxane and Pentoxifylline on Adriamycin Induced Cardiomyopathy / 소아과

PURPOSE: We hypothesized dexrazoxane (DXR) and pentoxifylline (PTX) may prevent myocardial damage in adriamycin (ADR) -induced cardiomyopathic rat model. We also investigated their effects on the myocardial apoptosis and fibrosis in ADR induced cardiomyopathy. METHODS: The six-week old female Spregue-Dawley rats were divided into control group (CNT, n= 4), ADR group (n=6), ADR+DXR group (DXR, n=5), ADR+PTX group (PTX, n=6), ADR+DXR+PTX group (DXPT, n=5). ADR (5 mg/week, twice) was administrated intravenously to rats except CNT group to induce cardiomyopathy. The PTX (50 mg/kg/day) was administered daily from day-0 to Day-21. The DXR (100 mg/kg) was administered 30 minutes before each ADR injection. On day 21, the rats were sacrificed and the degree of histopathologic changes of hypercontraction band necrosis, cytoplasmic vacuolar change and fibrosis were scored. Immunohistochemical staining for Bcl-2 expression and RT-PCR for TNF-alpha and CTGF were performed. RESULTS: Histopathological scores of myocardial damage were significantly higher in ADR rats than CNT rats (P< 0.05), and significantly lower in DXPT rats than ADR rats (P< 0.01). Myocardial fibrosis was prevented in both PTX rats and DXPT rats. The expression of Bcl-2 was weaker in ADR rats than that in CNT rats (P< 0.05), and stronger in both DXR and DXPT rats than that in ADR rats (P< 0.05). TNF-alpha concentration of ADR rats was not different from that of treated groups. CONCLUSION: DXR prevented myocyte apoptosis with increased Bcl-2 expression, and PTX prevented myocardial fibrosis in ADR induced cardiomyopathic rats. The combination therapy of DXR and PTX showed prevention of cardiomyopathy in ADR induced cardiomyopathy rat model.

Proper use of glomerular filtration rate estimating equations and standardization of serum creatinine measurements / 中华检验医学杂志

Chronic kidney disease(CKD)is a major public health problem worldwide. Understanding by doctors and laboratorians of the importance of reliable serum creatinine measurement in GFR estimation and of factors that may affect creatinine measurement is critical to ongoing public health efforts to improve the diagnosis and treatment of patients with CKD.We present an overview of the commonly used methods,their performances and limitations and the required performance criteria for the measurement of serum creatinine.Available resources for standardization of serum creatinine measurements and recommendations for creatinine measurement and GFR estimations are introduced.