I extracted one of them.
Urine sediment inspection is also called urine sediment inspection, which is an inspection method of centrifuging fresh urine and then inspecting urine sediment with a microscope [1]. Due to the development of instrumental analysis, the visible components in modern urine can be detected by non-centrifugation, laser fluorescence staining, flow analysis, (Sysmex UF50, UF 100) or computer automatic image recognition system (Iris IQ200), so it can also be called particle analysis in urine [2]. At present, most hospital laboratories in China are still accustomed to the traditional ordinary microscope inspection method. Because there are many visible components in urine, such as cells, tubes, microorganisms, crystals, etc., in order to further identify and identify these components, there are phase contrast microscope, polarizing microscope, fluorescence microscope, interference microscope, electron microscope, etc., which can be divided into staining method and non-staining method. Non-staining test is the simplest and most commonly used test method. The importance of urine visible component examination is that it is an indispensable examination method in urine analysis, which has important clinical significance for clinical diagnosis, treatment monitoring and health investigation. The types of cells entering the urinary tract, such as polycythemia, can be determined, suggesting urinary tract bleeding. Further examination of erythrocyte morphology is helpful to determine whether the bleeding comes from glomerulus or lower urinary tract. The increase of white (pus) cells suggests urinary tract infection; The proliferation of different urothelial cells is helpful to judge the location of various urinary tract diseases; The increase of cast often suggests glomerulonephritis, renal tubules (distal and collecting duct lesions) and renal insufficiency; It is also of great clinical value to find the crystallization of metabolism or the source of drugs [3].
A, urine visible component test method
There are many ways to check the formation of urine. The following is a brief description of the main points of the eight comparative selection methods:
1. traditional centrifugation method: 1997 national operating rules for clinical examination [4] (second edition) clearly stipulates the operating rules for microscopic examination of non-stained urine sediment and stained urine sediment, but the type of centrifuge is not specified in the operation, only 1500r/min centrifugation is specified for 5 minutes, and the urine retention time and inspection time are not specified. Microscopic observation 10× 10 storage type, 10×40, 10 field of view showed the lowest and highest values of cells. The observation tube type was identified by high-power microscope, but the counting number was observed by low-power microscope in 20 fields, and the average record result of one field was calculated. The author checked the urine test records of tertiary, secondary and primary hospitals. In some hospitals, urine sediment in urine cups or test tubes is directly poured onto glass slides (without cover), instead of quantitative glass plate counting, the traditional plus sign (-,+,++,++,+++) is still used in the report, and casts and epithelial cells are not classified, and a little,+,++is reported. Ward urine can often be retained a few hours before the examination (the regulations clearly stipulate that it is 6550 in the morning). It should be submitted for inspection within 1h) This traditional method is arbitrary and changeable, influenced by the subjectivity of the operator, with irregular judgment, inconsistent results and no comparability. Because the reporting method varies from person to person, it is a lack of standardized experimental method and should be eliminated.
2. Standard microscopic examination method: In view of the above situation, the clinical laboratory group of Laboratory Branch of Chinese Medical Association held three meetings on standardization of urine microscopic examination in 2002, and put forward suggestions on standardization of urine sediment examination [5]. It is suggested that the materials, instruments, specimens, collection and transportation, operation steps and contents of urine sediment report should be clearly defined. For example, the relative centrifugal force of containers, centrifugal tubes, urine sediment counting plates and centrifuges (horizontal) should be about 400×g, while microscopes require built-in light sources with adjustable light intensity, with objective lenses of 40 times, 10 times and eyepieces of 10 times. The collection, transportation and reception of specimens are clearly defined. This method is suitable for popularization in medical units at all levels, and it can be completed by speeding up reading-10 or Kova board. Because of uniform operation, accurate results and consistent reports, it is a recommended method for urine sediment inspection. The problem is how to establish a quality assurance system, carry out indoor quality control, closely contact clinical and ventricular interstitial evaluation, and regularly carry out professional training on sediment, so as to make urine sediment identification skilled and not miss the requirements of pathological tangible components [5].
3. Urine visible component staining method: The function of urine visible component staining is: (1) to prevent thrombus leakage; (2) to prevent misdiagnosis; (3) to prevent fatigue caused by long-term microscopic examination; (4) Create conditions for the long-term preservation of typical pathological components in urine, and provide atlas for teaching and scientific research. Chromosome methods of urine visible components can be divided into: ① single staining method; ② compound dyeing; ③ Staining in vivo; ④ Differential staining; ⑤ Special dyeing, etc [6]. Ito, Japan recommended a standard urine collection method and four staining methods. The urine examination scheme Gp 16A[7] published by NCCLS mentioned that "staining method is very helpful for the identification of cells and casts" and advocated Malbin staining (crystal violet and sand yellow method) and 0.5% toluidine blue. At the same time, the special staining methods for identifying one in ten thousand urine are listed: ① fat and oval fat body: oil red or Sudan red ⅲ; ② Bacteria: Gram staining and Pap staining [7]. Sternheimer staining method was used in European urine analysis group, and Ahlsien-blue-pyronin B)[2] b [2] was better than Sternheimer-Malbin staining method. Our urine laboratory also confirmed that S staining can make up for the shortcomings of S-M staining, which is the best of the six staining methods [8].
4. Particle filtration method in urine: a certain amount of urine (20~ 100ml) can be filtered through a special filter and pathological particles such as casts and cells can be retained on the filter [10], and some red blood cells can be observed under an electron microscope through the filter [1 1]. We have also seen commercial products with special syringes and filters in the urology laboratory of Bonn University Hospital in Germany. Unfortunately, because the filter screen must be dyed and identified, some cells dissolve after dyeing, and this method is expensive, so it is difficult to popularize [12].
5. Rapid screening method for non-centrifugal urine counting in cell counting pool: directly putting non-centrifugal urine into urine cell counting pool is a quantitative filtering method introduced in the national clinical laboratory operating procedures, which is not recommended in Europe. Because the results are not sensitive and standardized, the results are unstable [2]. However, the author once observed 5 cells× 2 in the improved blood cell counting pool of neubauer, the Sixth People's Hospital of Shanghai, and will get the experimental results soon. Urologists believe that it is beneficial to observe the condition and judge the curative effect and the trend of the condition. However, in foreign countries, it is emphasized that the fuchs-Rosenthal plate with a concentration of 0.2mm (with a total area of 0.0625mm2) is used for full liquid inspection, which has a wide field of vision and more accurate and reliable results [2].
6. Urine sediment workstation: The workstation integrates a camera microscope, a urine sediment counting board and a computer, such as Plyson AMP-2000U, Huaxin DiasysR/S, Hefei Xinyue SQ-3000, Meidetai Zengyang, Chongqing Tianhai US2020, Beijing Guolian Online QO-S Dyeing Urine Sediment Analyzer and Qiansheng QS8005 Process Urine Sediment Analyzer. Including standard mobile counting room, various keyboard controls \ standard bar code recognition, automatic cleaning, automatic sampling, and a visual field map can be copied when reporting). No matter which manufacturer produces the urine sediment workstation, standardization should be emphasized, that is, the amount of urine sample, centrifugal force, centrifugal time, sediment retention, microscope lens (preferably with phase contrast lens) and reporting method should meet the requirements of standard microscope. The advantage of this method is computer reporting. To clean the mobile computer board, it is necessary to remove protein dirt, count and identify it completely automatically, and avoid subjective factors.
7. Fluorescent dye flow cytometer: UF50 and UF- 100 urine sediment flow cytometer produced by Sysmex Company, which uses visible component DNA in sediment to contact with cell membrane and phenanthrene and carbonyl cyanide, and then carries out laser irradiation through sheath flow to generate forward scattered light intensity and fluorescence pulse width of each whisker component, and then measures the red blood cell and blood cell size scatter plot and histogram through electrical impedance. The instrument can automatically report five quantitative parameters of red blood cells, white blood cells, epithelial cells, casts and bacteria, and five qualitative parameters of small round epithelial cells, molds, pathological casts, crystals and sperm, and can also measure urine conductivity. Because there is no need for centrifugation, the detection speed is fast, the sensitivity and repeatability of pathological components are good, and because the detection step mode of each urine sample is consistent, it is convenient for quality control (using standard detection particles) and standardization. If it is combined with dry chemical test paper, it can also be observed by computer processing, which has been paid attention to in clinical diagnosis of hematuria, determination of urinary tract infection and understanding of renal function. The disadvantage of the instrument is its high price, which can not detect trichomonas, fat droplets, pathology and drug crystallization, nor can it identify virus inclusions or tumor cells; When there are a large number of bacteria, yeast, crystals and other particles in urine, it can interfere with the results of red blood cell counting; Shadow red blood cells and various pathological casts cannot be identified in the image [13].
8. In vitro diagnostic urine imaging system-Automatic Intelligent Microscope (AIM): 1983 The yellow IRIS microscope workstation was introduced by Iris Company, and various particles in urine were imaged on AIM and displayed on the fluorescent screen after computer processing. In 2000, the company introduced an improved large-scale 939UDX automatic urine analyzer, and in 2002, it passed the small IQ-200 system certified by the US Food and Drug Administration (FDA). Including patented slide-free microscope and unique high-speed code software, we can easily check all kinds of common tears in urine, that is, leukocytes, leukocytes, erythrocytes, squamous epithelial cells, non-squamous epithelial cells, transparent casts, unclassified casts, crystals, bacteria, yeast, sperm and mucus. The identification results can be modified according to the operator's needs to distinguish the subtypes of visible components in urine. IQ-200 is advanced in principle. It integrates the technical parameters such as size, contrast, shape and texture of various particles in urine, and judges the properties of particles by a highly sensitive computer. According to the preliminary report, the overall sensitivity of IQ-200 is 83% (including 89.4% red blood cells, 93.9% white blood cells and 93.9% bacteria). The overall specificity was 83.3% (including 89.2% erythrocytes, 88.8% leukocytes and 88. 1 bacteria). The reexamination rate by IQ-200 microscope can be lower than 5% (UF is often above 20%), but whether it is necessary to further identify various cell casts by this method, such as staining eosinophils with Hanson and staining fat casts with Sudan III, has not been solved. The instrument is small and portable, and a variety of pathological particles and related quality control particles are displayed on the screen. However, there is no pressure sheath flow system in this instrument, and there is no intuitive dyeing data. The manufacturer suggested comparing 456 urine samples with UF- 100 at the exhibition. IQ-200 found 14 pathological tubular UF- 100 detected 65438+.
Second, the identification of visible components in urine
There are more than 45 kinds of components in urine, which are relatively common.
1. Red blood cells: The typical red blood cells in urine are biconcave disc-shaped, light yellow, with a diameter of about 8um, which is easy to identify. However, due to the complexity and diversity of urine particles, the shape of urine red blood cells may change due to high temperature, long time, pH value change and osmotic pressure change. Inexperienced inspectors should distinguish it from yeast-like fungi, fungal spores, fat droplets, starch granules, calcium oxalate crystals, urate crystals and sperm heads. Pass the test.
2. White blood cells: The cells in urine are mainly neutrophils, and occasionally monocytes, lymphocytes and eosinophils. The appearance of white blood cells in fresh urine is complete, with a circular diameter of 65,438+00um ~ 65,438+04um. The granules in the cytoplasm are visible, and the nucleus is clear, which is often scattered. In hypotonic and alkaline urine, white blood cells often swell, and about half of them can be dissolved within 2 hours, while in hypertonic and acidic urine. Leukocyte plasma in old urine is gelatinous due to homogenization. When inflamed, most of the degenerated white blood cells have irregular appearance and vague structure. The cytoplasm can be filled with coarse particles and the nuclear structure is unclear. Cells often stick together, and the boundaries of cells are unclear, which is called pus cells. White blood cells can be divided into: (1) heavily stained cells: aged or dead white blood cells with deep staining; (2) lightly stained cells: lightly stained cells are active white blood cells, which can be seen when the urine specific gravity is > 10 15; (3) Flash cells: In hypotonic urine, neutrophils become larger and molecules move in the cytoplasm. You can see the flash phenomenon when the light is refracted. 3. Cast: It is an important component in the visible components of urine, and its quantity and type constitute a certain value for the diagnosis, treatment observation and post-judgment of renal parenchymal lesions. Three common cell casts are red blood cell cast, renal tubular epithelial cell cast and renal tubular epithelial cell cast.