Cell counting for in vivo flow cytometry signals with baseline drift

In biomedical research fields,the in vio Aow cytometry(IVFC)is a widely used technology which is able to monitor target cells dynamically in living animals.Although the setup of IVFC system has been well established,baseline drift is still a challenge in the process of quantifying circulating cells.Previous methods,i.e.,the dynamic peak picking method,counted cells by setting a static threshold without considering the baseline drift,leading to an inaccurate cell quantification.Here,we developed a method of cell counting for IVFC data with baseline drift by interpolation fitting,automatic segmentation and wavelet-based denoising.We demonstrated its performance for IVFC signals with three types of representative baseline drift.Compared with non-baseline correction methods,this method showed a higher sensitivity and specificity,as well as a better result in the Pearson's correlation coefficient and the mean-squared error(MSE).

Sensitivity of diagnosis of spontaneous bacterial peritonitis is higher with the automated cell count method

BACKGROUND Spontaneous bacterial peritonitis(SBP)is one of the most important complications of patients with liver cirrhosis entailing high morbidity and mortality.Making an accurate early diagnosis of this infection is key in the outcome of these patients.The current definition of SBP is based on studies performed more than 40 years ago using a manual technique to count the number of polymorphs in ascitic fluid(AF).There is a lack of data comparing the traditional cell count method with a current automated cell counter.Moreover,current international guidelines do not mention the type of cell count method to be employed and around half of the centers still rely on the traditional manual method.AIM To compare the accuracy of polymorph count on AF to diagnose SBP between the traditional manual cell count method and a modern automated cell counter against SBP cases fulfilling gold standard criteria:Positive AF culture and signs/symptoms of peritonitis.METHODS Retrospective analysis including two cohorts:Cross-sectional(cohort 1)and case-control(cohort 2),of patients with decompensated cirrhosis and ascites.Both cell count methods were conducted simultaneously.Positive SBP cases had a pathogenic bacteria isolated on AF and signs/symptoms of peritonitis.RESULTS A total of 137 cases with 5 positive-SBP,and 85 cases with 33 positive-SBP were included in cohort 1 and 2,respectively.Positive-SBP cases had worse liver function in both cohorts.The automated method showed higher sensitivity than the manual cell count:80%vs 52%,P=0.02,in cohort 2.Both methods showed very good specificity(>95%).The best cutoff using the automated cell counter was polymorph≥0.2 cells×10^(9)/L(equivalent to 200 cells/mm^(3))in AF as it has the higher sensitivity keeping a good specificity.CONCLUSION The automated cell count method should be preferred over the manual method to diagnose SBP because of its higher sensitivity.SBP definition,using the automated method,as polymorph cell count≥0.2 cells×10^(9)/L in AF would need to be considered in patients admitted with decompensated cirrhosis.

Blood cell counts and nonalcoholic fatty liver disease: Evidence from Mendelian randomization analysis

BACKGROUND Previous research has highlighted correlations between blood cell counts and chronic liver disease.Nonetheless,the causal relationships remain unknown.AIM To evaluate the causal effect of blood cell traits on liver enzymes and nonalcoholic fatty liver disease(NAFLD)risk.METHODS Independent genetic variants strongly associated with blood cell traits were extracted from a genome-wide association study(GWAS)conducted by the Blood Cell Consortium.Summary-level data for liver enzymes were obtained from the United Kingdom Biobank.NAFLD data were obtained from a GWAS meta-analysis(8434 cases and 770180 controls,discovery dataset)and the Fingen GWAS(2275 cases and 372727 controls,replication dataset).This analysis was conducted using the inverse-variance weighted method,followed by various sensitivity analyses.RESULTS One SD increase in the genetically predicted haemoglobin concentration(HGB)was associated with aβof 0.0078(95%CI:0.0059-0.0096),0.0108(95%CI:0.0080-0.0136),0.0361(95%CI:0.0156-0.0567),and 0.0083(95%CI:00046-0.0121)for alkaline phosphatase(ALP),alanine aminotransferase(ALT),aspartate aminotransferase,and gammaglutamyl transferase,respectively.Genetically predicted haematocrit was associated with ALP(β=0.0078,95%CI:0.0052-0.0104)and ALT(β=0.0057,95%CI:0.0039-0.0075).Genetically determined HGB and the reticulocyte fraction of red blood cells increased the risk of NAFLD[odds ratio(OR)=1.199,95%CI:1.087-1.322]and(OR=1.157,95%CI:1.071-1.250).The results of the sensitivity analyses remained significant.CONCLUSION Novel causal blood cell traits related to liver enzymes and NAFLD development were revealed through Mendelian randomization analysis,which may facilitate the diagnosis and prevention of NAFLD.

Rapid Detection of Somatic Cell Count Based on Hybrid Variable Selection Method

Somatic cell count detection is the daily work of dairy farms to monitor the health of cows.The feasibility of applying near-infrared spectroscopy to somatic cell count detection was researched in this paper.Milk samples with different somatic cell counts were collected and preprocessing methods were studied.Variable selection algorithm based on hybrid strategy and modelling method based on ensemble learning were explored for somatic cell count detection.Detection model was used to diagnose subclinical mastitis and the results showed that near-infrared spectroscopy could be a tool to realize rapid detection of somatic cell count in milk.

In-channel integration of designable microoptical devices using flat scaffold-supported femtosecond-laser microfabrication for coupling-free optofluidic cell counting

The high-precision integration of three-dimensional(3D)microoptical components into microfluidics in a customizable manner is crucial for optical sensing,fluorescence analysis,and cell detection in optofluidic applications;however,it remains challenging for current microfabrication technologies.This paper reports the in-channel integration of flexible two-dimensional(2D)and 3D polymer microoptical devices into glass microfluidics by developing a novel technique:flat scaffold-supported hybrid femtosecond laser microfabrication(FSS-HFLM).The scaffold with an optimal thickness of 1–5 μm is fabricated on the lower internal surface of a microfluidic channel to improve the integration of high-precision microoptical devices on the scaffold by eliminating any undulated internal channel surface caused by wet etching.As a proof of demonstration,two types of typical microoptical devices,namely,2D Fresnel zone plates(FZPs)and 3D refractive microlens arrays(MLAs),are integrated.These devices exhibit multicolor focal spots,elongated(>three times)focal length and imaging of the characters‘RIKEN’in a liquid channel.The resulting optofluidic chips are further used for coupling-free white-light cell counting with a success rate as high as 93%.An optofluidic system with two MLAs and a W-filter is also designed and fabricated for more advanced cell filtering/counting applications.

Deep learning method for cell count from transmitted-light microscope

Automatic cell counting provides an effective tool for medical research and diagnosis.Currently,cell counting can be completed by transmitted-light microscope,however,it requires expert knowledge and the counting accuracy which is unsatisfied for overlapped cells.Further,the image-translation-based detection method has been proposed and the potential has been shown to accomplish cell counting from transmitted-light microscope,automatically and effectively.In this work,a new deep-learning(DL)-based two-stage detection method(cGAN-YOLO)is designed to further enhance the performance of cell counting,which is achieved by combining a DL-based fluorescent image translation model and a DL-based cell detection model.The various results show that cGAN-YOLO can effectively detect and count some different types of cells from the acquired transmitted-light microscope images.Compared with the previously reported YOLO-based one-stage detection method,high recognition accuracy(RA)is achieved by the cGAN-YOLO method,with an improvement of 29.80%.Furthermore,we can also observe that cGAN-YOLO obtains an improvement of 12.11%in RA compared with the previously reported image-translation-based detection method.In a word,cGAN-YOLO makes it possible to implement cell counting directly from the experimental acquired transmitted-light microscopy images with high flexibility and performance,which extends the applicability in clinical research.

Automatic counting of retinal ganglion cells in the entire mouse retina based on improved YOLOv5

Glaucoma is characterized by the progressive loss of retinal ganglion cells (RGCs),although the pathogenic mechanism remains largely unknown.To study the mechanism and assess RGC degradation,mouse models are often used to simulate human glaucoma and specific markers are used to label and quantify RGCs.However,manually counting RGCs is time-consuming and prone to distortion due to subjective bias.Furthermore,semi-automated counting methods can produce significant differences due to different parameters,thereby failing objective evaluation.Here,to improve counting accuracy and efficiency,we developed an automated algorithm based on the improved YOLOv5 model,which uses five channels instead of one,with a squeeze-and-excitation block added.The complete number of RGCs in an intact mouse retina was obtained by dividing the retina into small overlapping areas and counting,and then merging the divided areas using a non-maximum suppression algorithm.The automated quantification results showed very strong correlation (mean Pearson correlation coefficient of 0.993) with manual counting.Importantly,the model achieved an average precision of 0.981.Furthermore,the graphics processing unit (GPU) calculation time for each retina was less than 1 min.The developed software has been uploaded online as a free and convenient tool for studies using mouse models of glaucoma,which should help elucidate disease pathogenesis and potential therapeutics.

Blood neutrophil extracellular traps:a novel target for the assessment of mammary health in transition dairy cows

Background:Mammary health is important for transition dairy cows and has been well recognized to exert decisive effects on animal welfare.However,the factors influencing mammary health are still unclear.Differential somatic cell count(DSCC)could reflect the mastitis risk since it is the percentage of neutrophils plus lymphocytes in total somatic cells and could be reflective of mammary health of dairy cows.This work aimed to investigate the assessment and prognosis of the health of transition cows based on blood neutrophil extracellular traps(NETs).Results:Eighty-four transition Holstein dairy cows were selected.The serum was sampled in all the animals at week 1 pre-and postpartum,and milk was sampled at week 1 postpartum.Based on the DSCC in milk at week 1,cows with lower(7.4%±4.07%,n=15)and higher(83.3%±1.21%,n=15)DSCCs were selected.High DSCC cows had higher levels of red blood cell counts(P<0.05),hemoglobin(P=0.07),and hematocrit(P=0.05),higher concentrations of serum oxidative variables[reactive oxygen species(P<0.05),malondialdehyde(P<0.05),protein carbonyl(P<0.05),and 8-hydroxy-2-deoxyguanosine(P=0.07)],higher levels of serum and milk NETs(P<0.05)and blood-milk barrier indicators,including serumβ-casein(P=0.05)and milk immunoglobulin G2(P=0.09),than those of low DSCC cows.In addition,lower concentrations of serum nutrient metabolites(cholesterol and albumin)(P<0.05)and a lower level of serum deoxyribonuclease I(P=0.09)were observed in high DSCC cows than in low DSCC cows.Among the assessments performed using levels of the three prepartum serum parameters(NETs,deoxyribonuclease I andβ-casein),the area under the curve(0.973)of NETs was the highest.In addition,the sensitivity(1.00)and specificity(0.93)were observed for the discrimination of these cows using NETs levels with a critical value of 32.2 ng/mL(P<0.05).Conclusions:The formation of NETs in blood in transition dairy cows may damage the integrity of the blood-milk barrier and thereby increase the risk for mastitis in postpartum cows.

Udder Health Status of First Parity Dairy Cows in Early-Lactation Based on Somatic Cell Count Categories

The main aim of this study was to investigate the prevalence of intramammary infection (IMI) in early-lactation of primiparous cows using milk recording cow composite somatic cell count (CSCC) categories (combining the first 2 milk recording results after calving). Another aim was to evaluate the milk urea (MU) content as a potential supplementary indicator to SCC or CSCC for the identification of IMI in primiparous cows after calving. This retrospective observational study was conducted on records of test-day of primiparous cows over a period of 6 years (January 2016 to December 2021. The SCC data for 158 Holstein Friesian primiparous cows, with their first milk recording 5 to 35 days after calving and their second milk recording 28 to 56 days in milk (DIM), were identified. Each primiparous cow was assigned a CSCC category (low-low, low-high, high-low or high-high) based on the CSCC at the first 2 milking recordings using the following cut-offs: ≤150,000 cells/ml (low), >150,000 cells/ml (high). The association between CSCC categories and MV content was analyzed using correlation models. At the first milk recording, a proportion of 63.29% was in the low SCC category, and the rest (36.71%) was in the high SCC category. At the second milk recording, a proportion of primiparous cows in CSCC categories was 59.49%, 3.80%, 27.85% and 8.86% in low-low, low-high, high-low and high-high, respectively. At the second milk recording, a proportion of 12.66% of primiparous cows was in the high CSCC category and a proportion of 87.34% of primiparous cows was in the low CSCC category, indicating a poor and a good udder health, respectively. The association of SCC with MU content in low and in high SCC categories at the first milk recording was positive and moderate (+0.49) and negative and strong (-0.97), respectively. The association of CSCC categories with MU contents at the second milk recording was inconclusive. We concluded that CSCC categories may be a useful tool for identifying success and problems regarding the udder health of primiparous cows in early lactation.

Lithium promotes proliferation and suppresses migration of Schwann cells

Schwann cell proliferation,migration and remyelination of regenerating axons contribute to regeneration after peripheral nervous system injury.Lithium promotes remyelination by Schwann cells and improves peripheral nerve regeneration.However,whether lithium modulates other phenotypes of Schwann cells,especially their proliferation and migration remains elusive.In the current study,primary Schwann cells from rat sciatic nerve stumps were cultured and exposed to 0,5,10,15,or 30 mM lithium chloride(LiCl)for 24 hours.The effects of LiCl on Schwann cell proliferation and migration were examined using the Cell Counting Kit-8,5-ethynyl-2′-deoxyuridine,Transwell and wound healing assays.Cell Counting Kit-8 and 5-ethynyl-2′-deoxyuridine assays showed that 5,10,15,and 30 mM LiCl significantly increased the viability and proliferation rate of Schwann cells.Transwell-based migration assays and wound healing assays showed that 10,15,and 30 mM LiCl suppressed the migratory ability of Schwann cells.Furthermore,the effects of LiCl on the proliferation and migration phenotypes of Schwann cells were mostly dose-dependent.These data indicate that lithium treatment significantly promotes the proliferation and inhibits the migratory ability of Schwann cells.This conclusion will inform strategies to promote the repair and regeneration of peripheral nerves.All of the animal experiments in this study were ethically approved by the Administration Committee of Experimental Animal Center of Nantong University,China(approval No.20170320-017)on March 2,2017.

Aquaporin-1 down regulation associated with inhibiting cell viability and inducing apoptosis of human lens epithelial cells

AIM：To investigate the role of Aquaporin-1（AQP-1）in lens epithelial cells（LECs）and its potential target genes.AQP-1 is specifically expressed in LECs of eyes and is significant for lens homeostasis and transparency maintenance.Herein,AQP-1 expression in LECs was investigated to evaluate its influence on cell survival in association with its potential role in cataract formation.·M ETHODS：LECs were transfected with lentivirus carrying AQP-1 small interfering RNA（si RNA）.Real-time polymerase chain reaction（PCR）and Western blotting were conducted to detect AQP-1 expression in LECs from different groups.Meanwhile,cell counting kit-8（CCK-8）assay and flow cytometry were performed to measure LEC proliferation and apoptosis,respectively.·RESULTS：AQP-1 expression was significantly reduced in LECs,both at m RNA and protein levels（〈0.05）,after si RNA treatment.Decreased cell viability was detected by CCK-8 assay in LECs with si RNA interference,compared to control cells（〈0.05）.The apoptosis rate significantly increased in cells after si RNA interference（〈0.05）.·CONCLUSION：The decreased cell viability following AQP-1 down regulation is largely due to its induction of apoptosis of LECs.AQP-1 reduction might lead to changes of physiological functions in LECs,which might be associated with the occurrence and development of cataracts.

A counting method for complex overlapping erythrocytes-based microscopic imaging

Red blood cell(RBC)counting is a standard medical test that can help diagnose various conditions and diseases.Manual counting of blood cells is highly tedious and time consuming.However,new methods for counting blood cells are customary employing both electronic and computer-assisted techniques.Image segmentation is a classical task in most image processing applications which can be used to count blood cells in a microscopic image.In this research work,an approach for erythrocytes counting is proposed.We employed a classification before counting and a new segmentation idea was implemented on the complex overlapping clusters in a microscopic smear image.Experimental results show that the proposed method is of higher counting accuracy and it performs much better than most counting algorithms existed in the situation of three or more RBCs overlapping complexly into a group.The average total erythrocytes counting accuracy of the proposed method reaches 92.9%.

Automatic counting method for complex overlapping erythrocytes based on seed prediction in microscopic imaging

Blood cell counting is an important medical test to help medical staffs diagnose various symptoms and diseascs.An automatic segmentation of complex overlapping erythrocytes based on seed prediction in microscopic imaging is proposed.The four main innovations of this ressearch are as.follows:(1)Regions of erythrocytes extracted rapidly and accurately based on the G component.(2)K-means algorithm is applied on edge detection of overlapping erythrocytes.(3)Traces of erythrocytes'biconcave shape are utilized to predict erythrocyte's position in overlapping clus-ters.(4)A new automatic counting method which aims at complex overlapping erythrocytes is presented.The experimental results show that the proposed method is efficient and accurate with very little running time.The average accuracy of the proposed method reaches 97.0%.

Effects of curcumin nanoparticles on proliferation and VEGF expression of human retinal pigment epithelial cells

AIM:To investigate the effects of curcumin(Cur)nanoparticles loaded with chitosan derivatives grafted by deoxycholic acid(Chit-DC)on human retinal pigment epithelial(h RPE)cell proliferation and vascular endothelial growth factor(VEGF)m RNA expression.METHODS:Cur nanoparticles were synthesized with Chit-DC as the carrier and Cur as the supported drug.Cell counting kit-8(CCK-8)method was used to detect the effects of different concentrations of Cur/Chit-DC,Chit-DC,and Cur on the proliferation of h RPE cells for different times.The changes of Cur/Chit-DC and Cur on h RPE cell cycle were determined by flow cytometry.Semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR)was used to detect the m RNA expression levels of VEGF in h RPE cells treated with Cur,Chit-DC and Cur/Chit-DC at 10μg/m L for 24 h.RESULTS:Different concentrations of Chit-DC nanoparticle treated h RPE cells had no significant difference in terms of optical density(OD)values compared with the control group at 24 h and 48 h.Moreover,there was no change in the cell morphology under a light microscope.After 24 h treatment with Cur/Chit-DC and Cur,the percentage of G0-G1 phase cells increased and the percentage of S phase cells decreased in all concentration groups.Cur/Chit-DC and Cur in all concentration groups inhibited the proliferation of h RPE cells in a time and dose dependent manner,and reduced the expression level of VEGF m RNA.CONCLUSION:The Cur/Chit-DC nanoparticles can release Cur continuously and have sustained release function.Both Cur/Chit-DC nanoparticles and Cur could inhibit h RPE cells cultured in vitro,and could reduce the expression level of VEGF m RNA in h RPE cells.

T lymphocyte proportion in Alzheimer’s disease prognosis

Bai et al investigate the predictive value of T lymphocyte proportion in Alzheimer's disease(AD)prognosis.Through a retrospective study involving 62 AD patients,they found that a decrease in T lymphocyte proportion correlated with a poorer prognosis,as indicated by higher modified Rankin scale scores.While the study highlights the potential of T lymphocyte proportion as a prognostic marker,it suggests the need for larger,multicenter studies to enhance generalizability and validity.Additionally,future research could use cognitive exams when evaluating prognosis and delve into immune mechanisms underlying AD progression.Despite limitations inherent in retrospective designs,Bai et al's work contributes to understanding the immune system's role in AD prognosis,paving the way for further exploration in this under-researched area.

Clinical comprehensive treatment protocol for managing diabetic foot ulcers:A retrospective cohort study

BACKGROUND Diabetic foot ulcers(DFUs)are a common complication of diabetes,often leading to severe infections,amputations,and reduced quality of life.The current standard treatment protocols for DFUs have limitations in promoting efficient wound healing and preventing complications.A comprehensive treatment approach targeting multiple aspects of wound care may offer improved outcomes for patients with DFUs.The hypothesis of this study is that a comprehensive treatment protocol for DFUs will result in faster wound healing,reduced amputation rates,and improved overall patient outcomes compared to standard treatment protocols.AIM To compare the efficacy and safety of a comprehensive treatment protocol for DFUs with those of the standard treatment protocol.METHODS This retrospective study included 62 patients with DFUs,enrolled between January 2022 and January 2024,randomly assigned to the experimental(n=32)or control(n=30)group.The experimental group received a comprehensive treatment comprising blood circulation improvement,debridement,vacuum sealing drainage,recombinant human epidermal growth factor and anti-inflammatory dressing,and skin grafting.The control group received standard treatment,which included wound cleaning and dressing,antibiotics administration,and surgical debridement or amputation,if necessary.Time taken to reduce the white blood cell count,number of dressing changes,wound healing rate and time,and amputation rate were assessed.RESULTS The experimental group exhibited significantly better outcomes than those of the control group in terms of the wound healing rate,wound healing time,and amputation rate.Additionally,the comprehensive treatment protocol was safe and well tolerated by the patients.CONCLUSION Comprehensive treatment for DFUs is more effective than standard treatment,promoting granulation tissue growth,shortening hospitalization time,reducing pain and amputation rate,improving wound healing,and enhancing quality of life.

Mast cell density and the context of clinicopathological parameters and expression of p185,estrogen receptor,and proliferating cell nuclear antigen in gastric carcinoma

AIM:To investigate the relationship between the mast cell density(MCD)and the context of clinicopathological parameters and expression of p185,estrogen receptor(ER), and proliferating cell nuclear antigen(PCNA)in gastric carcinoma. METHODS:Mast cell,p185,ER,and PCNA were detected using immunohistochemical S-P labeling method.Mast cell was counted in tissue of gastric carcinoma and regional lymph nodes respectively,and involved lymph nodes(ILN)were examined as usual. RESULTS:MCD was significantly related to both age and depth of penetration(x^2=4.688,P<0.05 for age and x^2=9.350, P<0.01 for depth of penetration)between MCD>21/0.03 mm^2 and MCD≤21/0.03 mm^2 in 100 patients;MCD in 1-6 ILN group patients was significantly higher than that in 7-15 ILN or>15 ILN group patients(u=6.881,8.055,P<0.01); There were significant differences intergroup in positive expression rate of p185,ER and PCNA between MCD>21/ 0.03 mm^2 and MCD≤21/0.03 mm^2 in 100 patients. CONCLUSION:Mast cell may have effect on inhibiting invasive growth of tumor,especially in the aged patients; The number of mast cells,in certain degree,may predicate the number of involved lymph nodes,which is valuable for assessment of prognosis;MCD was related to the expression of p185,ER,and PCNA in gastric carcinoma.It suggests that mast cell accumulation may inhibit the proliferation and the dissemination of the gastric carcinoma. INTRODUCTION Recently,many studies have reported on the association of mast cell with various tumorst.In several malignancies,mast cell has been found to correlate with growth,penetration and prognosis of tumor.Therefore,our study was undertaken to investigate the relationship between the mast cell density (MCD)and the context of clinicopathological parameters and expression of p 185,estrogen receptor(ER),and proliferating cell nuclear antigen(PCNA)in gastric carcinoma.

Accuracy of the automated cell counters for management of spontaneous bacterial peritonitis

AIM： To evaluate the accuracy of automated blood cell counters for ascitic polymorphonuclear （PMN） determination for： （1） diagnosis, （2） efficacy of the ongoing antibiotic therapy, and （3） resolution of spontaneous bacterial peritonitis （SBP）. METHODS： One hundred and twelve ascitic fluid samples were collected from 52 consecutive cirrhotic patients, 16 of them with SBP. The agreement between the manual and the automated method for PMN count was assessed. The sensitivity/specificity and the positive/negative predictive value of the automated blood cell counter were also calculated by considering the manual method as the ＂gold standard＂ RESULTS： The mean ＋ SD of the difference between manual and automated measurements was 7.8 4- 58 cells/ram3, while the limits of agreement were ＋124 cells/mm3 [95% confidence interval （CI）： ＋145 to ＋103] and -108 cells/mm3 （95% CI： -87 to -129）. The automated cell counter had a sensitivity of 100% and a specificity of 97.7% in diagnosing SBP, and a sensitivity of 91% and a specificity of 100% for the efficacy of the ongoing antibiotic therapy. The two methods showed a complete agreement for the resolution of infection. CONCLUSION： Automated cell counters not only have a good diagnostic accuracy, but are also very effectivein monitoring the antibiotic treatment in patients with SBP. Because of their quicker performance, they should replace the manual counting for PMN determination in the ascitic fluid of patients with SBP.

Relationship of Somatic Cell Count with Milk Yield and Composition in Chinese Holstein Population

The objective of this study was to analyze the relationship of somatic cell count （SCC） with milk yield, fat and protein percentage, fat and protein yield using analysis of variance and correlation analysis in Chinese Holstein population. The 10 524 test-day records of 568 Chinese Holstein Cattle were obtained from 2 commercial herds in Xi＇an region of China during February 2002 to March 2009. Milk yield, fat percentage, fat and protein yield initially increased and then dropped down with parity, whereas protein percentage decreased and SCC increased. Analysis of variance showed highly significant effects of different subclasses SCC on milk yield and composition （P〈 0.01）. Compared with milk yield with SCC ≤ 200 000 cells mL-1, milk yield losses with SCC of 200 000-500 000 cells mL-1, 501000-1 000 000 cells mL-1, ≥ 1 000 000 cells mL-1 were 0.387, 0.961 and 2.351 kg, respectively. The highly significant negative correlation coefficient between somatic cell score （SCS） and milk and protein yield, milk yield and fat and protein percentage, protein percentage and fat yield were -0.084, -0.037, -0.061, -0.168, and -0.088, respectively （P〈 0.01）. The highly significant positive correlation coefficients between SCS and fat yield and fat and protein percentage, milk yield and fat and protein yield, fat percentage and protein percentage and fat yield, protein yield and protein percentage and fat yield were 0.041, 0.177, 0.105, 0.771, 0.865, 0.122, 0.568, 0.318, and 0.695, respectively （P〈 0.01）. There was no significant relationship between fat percentage and protein yield （P 〉 0.05）. The results of the present study first time provide the relevant base-line data for assessing milk production at Xi＇an region of China.

Normal Reference Value of Red Blood Cell Count of Chinese Presenile Men and Geographical Factors

This paper aims at providing a scientific basis for unifying the normal reference value standards of red blood cell count of Chinese presenile men. The paper, using microscopical counting method, studies the relationship between the normal reference values of 38,061 samples of red blood cell count of presenile men and eight geographical factors in 297 units in China. It is found that the correlation of geographical factors and the normal reference value of red blood cell count of presenile men is quite significant （F=303.00, P=-0.000）. By using the method of stepwise regression analysis, one regression equation is inferred. It is concluded that if geographical data are obtained in a certain area, the normal reference value of red blood cell count of presenile men in this area can be reckoned by using the regression analysis. Furthermore, according to the geographical factors, China can be divided into eight regions： Northeast China Region, North China Region, Shanxi-Shaanxi-Irmer Mongolia Region, Middle and Lower Reaches of the Changjiang River Region, Southeast China Region, Northwest China Region, Southwest China Region and Qinghai-Tibet Plateau Region.