Comparison of corneal biomechanical parameters between keratoconus and laser corneal refractive surgery / 眼科新进展

Objective To measure biomechanical parameters of the cornea after keratoconus and laser corneal refractive surgery by Scheimpflug noncontact tonometry (Corvis ST),and analyze the changes and differences in these parameters.Methods From April 2011 to November 2016,63 patients (96 eyes) with clinically diagnosed as keratoconus were selected as the keratoconus group,and 60 patients (120 eyes) underwent laser corneal refractive surgery between November 2016 to March 2017 were selected as postoperative cornea group,and totally 51 healthy person (102 eyes) who received physical examination during the same period were selected as healthy cornea group.Scheimpflug noncontact tonometry (Corvis ST) was performed to measure the length of appl 1,length of appl 2,velocity of appl 1,velocity of appl 2,maximum deformation amplitude,apex distance and radius of curvature in the three groups.Total comparison of biomechanical parameters was performed using ANOVA test among the three groups,while pairwise comparison was performed to analyze the difference of these parameters by SNK methods.Pearson or Spearman correlation analysis was applied to assess the differences in corneal morphological and biomechanical parameters.Results There was no significant difference in length of appl 1,length of appl 2 of the three groups (all P ＞ 0.05).And velocity of appl 1 in the keratoconus group was significantly higher than that of the healthy cornea group [(0.189 ± 0.230) m · s-1 vs.(0.151 ± 0.017)m · s-1] (P ＜ 0.05).As for velocity of appl 2,the keratoconus group was larger than the healthy cornea group,both which were larger than the postoperative cornea group,and the differences were significant (all P ＜ 0.05).And this was true of maximum deformation amplitude in the three groups,with the significant differences(all P ＜ 0.05).The apex distance in the keratoconus group was significantly longer than that in the healthy cornea group (P ＜ 0.05).The radius of curvature of the keratoconus group,postoperative cornea group and healthy cornea group were (5.696 ± 0.881) mm,(7.129 ± 0.681) mm and (7.012 ± 0.728) ram,respectively,which approached significant differences(all P ＜ 0.05).There was significant correlation between the anterior surface refractive power (Km) and apex distance and radius of curvature in the keratoconus group (r =-0.205,0.1 84;P =0.023,0.041),and maximum posterior surface elevation had a statistically significant correlation with velocity of appl 2,maximum deformation amplitude and radius of curvature (r =-0.579,-0.307,0.256,P =0.022,0.002,0.000).For the eyes in the postoperative cornea group,there were no significance correlation between the anterior surface refractive power (Km) and biomechanical properties (P ＞ 0.05),but significant correlation with length of appl 2 (r =-0.297,P =0.026).There were no significant correlation between maximum posterior surface elevation and biomechanical properties (P ＞ 0.05).Conclusion The corneal biomechanical parameters are decreased in eyes after keratoconus and laser corneal refractive surgery,and Corvis ST can become an auxiliary examination tool for earlier diagnosis of secondary keratoconus after corneal refractive surgery.

Effect of ceftriaxone on the intestinal epithelium and microbiota in neonatal mice / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effect of ceftriaxone on the intestinal epithelium and microbiota in mice in the early-life stage, as well as the recovery of the intestinal epithelium and reconstruction of intestinal microbiota in adult mice.</p><p><b>METHODS</b>A total of 36 BALB/C neonatal mice were randomly divided into control group and experimental group, with 18 mice in each group. The mice in the experimental group were given ceftriaxone 100 mg/kg every day by gavage within 21 days after birth. Those in the control group were given an equal volume of normal saline by gavage. Immunohistochemistry was used to measure the expression of Ki67, Muc2, and ZO-1 in the intestinal epithelium. qPCR and next-generation sequencing were used to analyze the overall concentration and composition of fecal bacteria.</p><p><b>RESULTS</b>After 21 days of ceftriaxone intervention, the experimental group had a significant reduction in body weight, a significant reduction in the expression of Ki67 and ZO-1 and a significant increase in the expression of Muc2 in intestinal epithelial cells, a significant reduction in the overall concentration of fecal bacteria, and a significant increase in the diversity of fecal bacteria compared with the control group (P<0.05). Firmicutes was the most common type of fecal bacteria in the experimental group, and there were large amounts of Staphylococcus and Enterococcus. The experimental group had a certain degree of recovery of the intestinal epithelium, but there were still significant differences in body weight and the structure of intestinal microbiota between the two groups at 56 days after birth (P<0.05).</p><p><b>CONCLUSIONS</b>Early ceftriaxone intervention significantly affects the development of the intestinal epithelium and the construction of intestinal microbiota in the early-life stage. The injury of the intestinal microbiota in the early-life stage may continue to the adult stage and affect growth and development and physiological metabolism.</p>

EEG characteristics of medial prefrontal cortex in rats with morphine dependent place preference under shuttling condition / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the correlation between EEG characteristics of medial prefrontal cortex (mPFC) and drug-seeking behavior of rats with morphine dependent place preference under shuttling condition.</p><p><b>METHODS</b>Forty rats were randomly divided into four groups (n = 10): morphine PL group, NS PL group, morphine IL group and NS IL group. After embeding the electrode in prelimbic (PL) or infralimbic (IL) cortex of each group by brain stereotaxic operation, the model of morphine dependent conditioned place preference (CPP) in rats was established. The differences of EEG wave percentage in mPFC were telemetered and analyzed when rats shuttled before and after the model.</p><p><b>RESULTS</b>After the model, the withdrawal symptoms were evident in morphine PL and IL group, and the activity time and distance in white box were increased obviously. Compared with control group, after the model, the EEG in morphine PL group showed that: when the rats shuttled to white box, 8 wave decreased obviously, P wave increased obviously. When the rats shuttled to black box, brain waves showed opposite changes. The EEG in morphine IL group showed that: when the rats shuttled to white box, a wave increased obviously, P and a wave decreased obviously. When the rats shuttled to black box, the brain wave had no significant differences compared with control group.</p><p><b>CONCLUSION</b>The EEG changes are different in PL and IL cortex of morphine CPP rats under shuttling condition, and the EEG changes are also different when rats shuttling to white or black box. There is possibly different mechanism, when different drug-seeking environmental cues caused EEG changes in different regions of mPFC.</p>

Wireless telemetry electrical activity of nucleus accumbens shell in morphine-induced CPP rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To analyse the relationship between the electrical activity changes of nucleus accumbens (NAc) shell and the drug-seeking behavior by recording NAc shell electrical activity in conditioned place preference (CPP) rats induced by morphine.</p><p><b>METHODS</b>Forty SD rats were randomly divided into operation-only control group and the morphine-induced CPP group after stereotaxic electrode was buried on rats NAc shell and the latter group was used to establish the morphine CPP model(n = 20). A CPP video system combining with the technique of electrical activity wireless telemetry was used in the study. The NAc electrical activity from each group of rats was recorded by wireless telemetry respectively, which included staying in black or white chamber of video box, shuttling between black-white chambers and between white-black chambers. The electrical activity differences were analyzed by the percentage of each wave.</p><p><b>RESULTS</b>When the morphine-induced rats staying in black chamber, compared with the operation-only control group, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P < 0.05, P < 0.01); when the morphine-induced rats staying in white chamber, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz and 30 - 40 Hz were increased(P < 0.05 , P < 0.01) , that of 10 - 20 Hz was reduced(P < 0.05 , P < 0. 01); when the morphine-induced rats in black- white shuttling status, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P <0.05, P <0.01), that of 10- 30 Hz was reduced( P <0.05); and in the white-black shuttling status, the electrical activity showed that the percentage of 0 - 10 Hz was reduced(P <0.05), that of 10 - 30 Hz was increased(P < 0.05) ; the electrical activity was further compared between staying status and shuttling status in the morphine-induced CPP group. There was no significant difference of electrical activity between the rats in white-black shuttling status and staying in white chamber. However, when rats in black-white shuttling status, compared with staying in black chamber, the electrical activity showed that the percentage of 0 - 10 Hz and 40 - 50 Hz were increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P <0.05).</p><p><b>CONCLUSION</b>The electrical activity changes of NAc shell in morphine-induced CPP rats were different from those of the operation-only control group, and these changes might be associated to the rat's drug-seeking behavior.</p>

Alteration of neural oscillations in hippocampal CA3 area in the fast avoidance response rat before and after electric shock avoidance training / 生理学报

The purpose of the present study is to explore the relationship of spatial learning ability and specific electrical activities of neural oscillations in the rat. The fast and general avoidance response groups were selected on the basis of the animals' responses to the electric shock in Y type maze, and their local field potentials (LFPs) of hippocampal CA3 area were recorded by wireless telemetry before and after shock avoidance training, respectively. The components of neural oscillations related to spatial identifying and learning ability were analyzed. The results showed that, compared with the general avoidance response group, the fast avoidance response group did not show any differences of LFPs in hippocampal CA3 area before electric shock avoidance trial, but showed significantly increased percentages of 0-10 Hz and 30-40 Hz rhythm in right hippocampal CA3 area after the shock avoidance training (P < 0.01 or P < 0.05). Fast Fourier transform showed that percentage increase of 0-10 Hz band occurred mainly in θ (3-7 Hz) frequency, and 30-40 Hz frequency change was equivalent to the γ1 band. Furthermore, compared with those before training, only the percentages of β, β2 (20-30 Hz) and γ1 rhythm increased (P < 0.01 or P < 0.05) in fast avoidance response rats after training, while the θ rhythm percentage remained unchanged. In contrast, θ rhythm percentage and the large amplitude (intensity: +2.5 - -2.5 db) θ waves in right CA3 area of general avoidance response rats were significantly reduced after training (P < 0.01). These results suggest that the increased percentages of β2 and γ1 rhythm and high-level (unchanged) percentage of θ rhythm in the right hippocampus CA3 area might be related to strong spatial cognition ability of fast avoidance response rats.

A wireless telemetry study on the electrical activity in nucleus accumbens of heroin-induced place preference rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To analyze the electrical activity property changes in nucleus accumbens (NAc) of heroin-induced conditioned place preference (CPP) rats during different stages of heroin dependence and to explore NAc's roles in the formation of drug dependence.</p><p><b>METHODS</b>Recording electrodes were bilaterally embedded into the NAcs of rats with the aid of stereotaxic apparatus, followed by establishment of heroin-dependent rat model. The NAc electrical activity during 3 different stages of heroin dependence, including heroin pre-exposure, immediate post-exposure and heroin withdrawal, were respectively recorded using EEG wireless telemetry techniques. The frequency distribution (ranging from 0.5 to 30 Hz) and the amplitude of NAc electrical activity were analyzed and measured.</p><p><b>RESULTS</b>Heroin-dependent rat models were successfully established and their withdrawal symptoms were evident. All rats showed a conditioned place preference (CPP) for the white box after 5-10 days of heroin-exposure, and displayed a maximum withdrawal symptoms on 2d after heroin- withdrawal. During all statges of heroin-dependence, the NAc electrical activity contained the highest proportion of delta rhythm and the lowest proportion of alpha2 rhythm. The discharge frequence band was similar across different stages. There was a significantly increased ratio of low-frequency discharges (delta rhythm) and decreased ratio of high-frequency discharges (beta rhythm) in NAc of rats during the immediate post- heroin exposure stage when compared with that during pre-exposure and heroin withdrawal stages. During the withdrawal stage, the ratio of at rhythm was significantly lower than during pre- and post-heroin exposure stages (P < 0.01). Further, the mean discharge amplitude in NAcs during immediate post-exposure and withdrawal stages was significantly increased relative to pre-exposure stage. However, the mean discharge amplitude during heroin withdrawal stage was significantly lower than during immediate post-exposure stage.</p><p><b>CONCLUSION</b>The electrical activity properties in rat NAcs showed a significant change during different stages of heroin-dependence, which suggested that neuronal activities in NAcs might contribute to the modulation of drug-dependence.</p>

Wavelet packet extraction and entropy analysis of telemetry EEG from the prelimbic cortex of medial prefrontal cortex in morphine-induced CPP rats / 生理学报

The purpose of the present study is to analyze the relationship between the telemetry electroencephalogram (EEG) changes of the prelimbic (PL) cortex and the drug-seeking behavior of morphine-induced conditioned place preference (CPP) rats by using the wavelet packet extraction and entropy measurement. The recording electrode was stereotactically implanted into the PL cortex of rats. The animals were then divided randomly into operation-only control and morphine-induced CPP groups, respectively. A CPP video system in combination with an EEG wireless telemetry device was used for recording EEG of PL cortex when the rats shuttled between black-white or white-black chambers. The telemetry recorded EEGs were analyzed by wavelet packet extraction, Welch power spectrum estimate, normalized amplitude and Shannon entropy algorithm. The results showed that, compared with operation-only control group, the left PL cortex's EEG of morphine-induced CPP group during black-white chamber shuttling exhibited the following changes: (1) the amplitude of average EEG for each frequency bands extracted by wavelet packet was reduced; (2) the Welch power intensity was increased significantly in 10-50 Hz EEG band (P < 0.01 or P < 0.05); (3) Shannon entropy was increased in β, γ₁, and γ₂waves of the EEG (P < 0.01 or P < 0.05); and (4) the average information entropy was reduced (P < 0.01). The results suggest that above mentioned EEG changes in morphine-induced CPP group rat may be related to animals' drug-seeking motivation and behavior launching.

Expression, purification and crystallization of rat brain kinesin / 生物工程学报

Kinesin is a motor protein that uses the energy from ATP hydrolysis to move along the microtubule system. To investigate how the chemical energy stored in ATP is converted to mechanical movement, the corresponding N-terminal region of rat brain kinesin was expressed in BL21-Codon Plus (DE3)-RP competent cells. After SP-cation exchange chromatography and size exclusion chromatography, the protein yield reached 10 mg/L culture with the purity above 95%. The purified protein had ATPase activity and specifically reacted with the kinesin antibody in the Western blotting analysis. The purified kinesin was crystallized under the following condition: 1.7 mol/L (NH4)2SO4, 500 mmol/L NaCl, 20% glycerol. The kinesin crystal can diffract up to 2.0 angstroms resolution.

Crystallography of ATP hydrolysis mechanism in rat brain kinesin / 生物工程学报

Rat brain kinesin is a conventional kinesin that uses the energy from ATP hydrolysis to walk along the microtubule progressively. Studying how the chemical energy in ATP is utilized for mechanical movement is important to understand this moving function. The monomeric motor domain, rK354, was crystallized. An ATP analog, AMPPNP, was soaked in the active site. Comparing the complex structure of rK354 x AMPPNP and that of rK354ADP, a hypothesis is proposed that Glu237 in the Switch II region sensors the presence of gamma-phosphate and transfers the signal to the microtubule binding region.

Research and implementation of cooperative cache for PVFS / 药物分析学报

At present, there are many effective ways to achieve high performance in cluster system storage management, including server-end disk, server-end caching, local caching and cooperative caching. The cooperative caching mechanism shares caches among different clients so as to avoid expensive disk access costs and to improve overall throughput of cluster system. In this paper, a Single Copy Cooperative Cache model is proposed together with block lookup algorithm, block replacement algorithm and the consistency algorithm based on the model. Meanwhile, the prototype system of the model is implemented in PVFS file system. Finally, the performance of this system is tested in InfiniBand Framework, the result of which shows that in contrast to the original PVFS system, read performance of PVFS file system is improved by about two times, while write performance is reduced by nearly ten percent.

Fruit-specific RNAi-mediated Lcy gene enhances content of lycopene in tomatoes silencing / 生物工程学报

Tomatoes ( Lycopersicon esculentum Mill.) are the principal dietary source of Lycopene which is one of carotenoid and is highly beneficial in preventing some diseases such as the cancer and the heart disease. Suppressing the expression of Lcy gene, the main gene regulating the transformation of the lycopene, is a convenient and effective way to enhance the content of lycopene. The primers were designed according to the gene sequence(U46919)and (X86452) in GenBank. The fruit-specific promoter--phytoene desaturase gene(Pds) promoter and the DNA segment of the Lcy gene were isolated from the genome DNA of tomatoes. The 3'end of Lcy DNA segment was connected together by an intron to inform the RNA interferential segment then which was inserted in the expression vector with the Pds promoter to inform the fruit-specific expression vector. The vector was transformed into the tomatoes through the Agrobacterium tumefaciens. Five transformants were obtained. And the PCR proved that the extra-gene was integrated into the tomato genome. The lycopene in the transgenic tomatoes fruit was increased significantly through analysing the contents of lycopene. These results show that regutating biosynthetic enzyme in carotenoid pathway by RNAi can improve the lycopene content of plant-derived products.

Penile squamous carcinoma in circumcised patients: a report 17 cases / 中华男科学杂志

<p><b>OBJECTIVE</b>To discuss the diagnosis and treatment of penile carcinoma in circumcised men.</p><p><b>METHODS</b>We reviewed 17 cases of penile carcinoma detected 1 month to 16 years after circumcision performed in our hospital from January, 1997 to December, 2004.</p><p><b>RESULTS</b>Of the total number, 11 cases were diagnosed as penile carcinoma 1 - 12 months and the others 3 - 16 years after the circumcision. Sixteen of them were treated by partial penectomy, anti 1 first by extensive circumcision and later by partial and total penectomy successively after recurrence. Cloquet nodes biopsy showed 16 cases to be pathologically well-differentiated and I case moderately differentiated penile squamous carcinoma. One died of extensive metastasis, but the other 16 remained disease-free survivals.</p><p><b>CONCLUSION</b>Circumcised adult men, especially those over 40 years of age, are likely to develop penile carcinoma. Patients with inflammation, plaque or ulcer in the prepuce should be checked by pathological biopsy and followed up closely. For Stage-I penile squamous carcinoma, partial penectomy is shown to be an effective therapeutic option, and Cloquet's nodes biopsy is necessary for all patients.</p>

Inverted urothelial papilloma: report of 151 cases / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the clinical features, pathology, diagnosis and treatment of inverted urothelial papilloma.</p><p><b>METHODS</b>A total of 151 cases of urothelial inverted papilloma were analysed retrospectively. Of the cases, 134 were male and 17 were female, with a mean age of 54 years old. Most patients complained of painless gross hematuria. The diagnosis could be established mainly by ultrasonic, intravenous urography, retrograde pyelography, cystoscope and pathology. Among them, 7 cases who had the papilloma at upper urinary tract underwent nephroureterectomy except one. One hundred and forty-four cases had the papilloma at low urinary tract, with 124 treated by transurethral bladder tumor resection (TURBT), among which 11 cases accompanying benign prostatic hyperplasia were treated by transurethral prostatic resection, 3 by transurethral resection of prostatic urethral tumor, 15 by partial cystectomy, 2 by total cystectomy.</p><p><b>RESULTS</b>One hundred and eighteen cases were followed up 1 year to 12.5 years (mean 6.3 years). Intravesical recurrence was found in 5 cases. Of them 2 cases developed malignance in 8 and 30 months postoperatively, and 1 case underwent total cystectomy.</p><p><b>CONCLUSIONS</b>Inverted urothelial papilloma is a benign tumor, which appears male predominant. Most of the lesions are found in the bladder. TURBT is the preferred treatment choice for inverted papilloma of the bladder. Although this disease has a good prognosis, regular follow-up observations are necessary.</p>

Effect of rhodiola on lipidperoxides and ultrastructure of mitochondria in the brain of senile mice / 中国组织工程研究

BACKGROUND: Senility is the degenerative change of every tissue and organ in biological body,which is the result due to comprehensive actions of various pathological and physiological processes. Rhodiola is a kind of natural medical plant,acting on delaying organic senility,preventing and treating senile disorders,etc. But the definite mechanisms on those have been unknown yet.OBJECTIVE: To probe into the mechanism of rhodiola extract( nuodikang capsule) on anti-senility.DESIGN: Randomized,controlled experimental research based on the experimental animals.SETTING: Neurological internal department in a military hospital affiliated to a university of Chinese PLA.MATERIALS: The experiment was performed in Pathology Experiment Room of Fourth Military Medical University of Chinese PLA from March to August 2002. Sixty Kunming mice were randomized into normal control group,model group,3 dosage groups of 1,2,4 g/kg of nuodikang successively and Vitamin E(Vit. E) positive control group 0. 1 mg/kg,10 mice in each group.INTERVENTIONS: In the model,nuodikang groups and Vit. E positive control,physiological saline solution of D-galactose 30 g/Lwas applied in subcutaneous at the back of neck,150 mg/kg per day,continuously for 8weeks. Simultaneously,in nuodikang group and Vit. E positive control,the medicine was applied by gastric perfusion,once daily,continuously for 8weeks.MAIN OUTCOME MEASURES: Effects of nuodikang capsule on activity of lactate dehydrogenase(LDH),the content of lipidperoxides(LPO),the activity of superoxide dismutase(SOD) in the brain,the content of malondialdehyde (MDA) and ultrastructure of mitochondrion in hippocampal neurons.RESULTS: In nuodikang capsule groups of 1,2,4 g/kg,the significant differences(P ＜ 0.05) presented in LPO content in brain tissue[(30. 1±2.9),(27.8±3.1),(26.9±1.9) nmol/g] and MDA content [(110.2±13.5),(95.4±20.1),(90.2±16.5) nmol/g],1 compared with the model group[ (33.4 ± 2.2),(126.5 ± 17.2) nmol/g],indicating significant differences(P ＜ 0.05),and LDH activity[(1.74±0. 14),(1.92 ±0. 23),(2.04 ±0.21) NU/g] and SOD activity[ (119. 1 ±2.2),(121.3 ± 0.9),(126.4 ± 2.0) NU/g] were remarkably increased,compared with the model group[ (1.68 ±0. 19),(115.9 ±2. 1) NU/g],indicating significant differences( P ＜ 0.05) . It was indicated by electro-microscope that nuodikang capsule groups of 2,4 g/kg acted on obvious protection on degenerative change of mitochondrion in hippocampal neurons caused by galactose.CONCLUSION: Nuodikang capsule acts significantly on anti-senility,which is related to its anti-oxidative injury and protection on neurons.

Erectile function evaluation after adult circumcision / 中华男科学杂志

<p><b>OBJECTIVE</b>To evaluate the erectile function of adults after circumcision.</p><p><b>METHODS</b>Ninty-five patients were investigated on erectile function by questionnaire before and after circumcision, respectively.</p><p><b>RESULTS</b>Eighteen patients suffered from mild erectile dysfunction before circumcision, and 28 suffered from mild or moderate erectile dysfunction after circumcision(P = 0.001). Adult circumcision appeared to have resulted in weakened erectile confidence in 33 cases(P = 0.04), difficult insertion in 41 cases(P = 0.03), prolonged intercourse in 31 cases(P = 0.04) and improved satisfaction in 34 cases(P = 0.04).</p><p><b>CONCLUSIONS</b>Adult circumcision has certain effect on erectile function, to which more importance should be attached.</p>

Evaluation of nephron-sparing surgery for renal cell carcinoma / 中华泌尿外科杂志

Objective To evaluate the indications and intraoperative management of nephron-spar- ing surgery (NSS) for renal cell carcinoma (RCC).Methods A total of 53 patients (32 men and 21 women;age range,21 -76 years) with unilateral RCC and a normal contralateral kidney underwent NSS.The disease course ranged from 1 week to 13 months.The unilateral RCCs were detected by B-uhrasonography. Partial nephrectomy was performed on 38 cases of polar RCC and wedge nephrectomy was performed on 15 cases of central RCC.Both renal vein and artery were blocked for 10 - 15 min,and unclamped for 1 -2 min if necessary.The resections were finished within 7 -21 min (mean,12 min).No inosine and regional hypo- thermia were used during operation.Absorbable hemostatic gauze and terylene flake were used to suture renal wound surface.After operation all patients were treated with interferon hypodermic injection of 5 000 000 U every other day for 3 months.Results The diagnosis of RCC with negative cutting margin was confirmed by pathological examination in all patients.The greatest dimension of the renal cancers were＜4 cm except for one of 6 cm.The clinical stage was T_1N_0M_0 in all patients.During the follow-up of 6 -48 months,all pa- tients were alive without recurrence and had normal renal function.Conclusions NSS can be rapidly per- formed for T_1 stage renal cancer＜4 cm or single clearly localized cancer＞4 cm in diameter.The follow-up results are satisfactory.