BACKGROUND: It is of great importance in improving the clinical effect of human islet allograft to study and design models of such large animals as pigs or primates preclinically.OBJECTIVE: To evaluate the effect of different doses of streptozotocin (STZ) on inducing diabetes type Ⅰ models of nonhuman primates.DESIGN, TIME AND SETTING: A contrast observational animal experiment was performed in the Cell Transplantation and Gene Therapy Center, the Third Xiangya Hospital of Central South University from October 2007 to December 2008. MATERIALS: A total of 21 adult male rhesus monkeys were divided into a 125 mg/kg STZ group (n =5), a 75 mg/kg STZ group (n=5) and a 50 mg/kg STZ group (n=11).METHODS: STZ weighed with regard to body mass of animals was prepared into 25 g/L STZ solution with buffer that was prepared in advance. After being filtered and degermed, the new-prepared STZ of 125 mg/kg, 75 mg/kg and 50 mg/kg were administered by intravenous injection into the experimental monkeys respectively, which took 1-5 minutes.MAIN OUTCOME MEASURES: Liver and renal function, glucose metabolism and histomorphological changes of animals during 1-16 weeks following administration.RESULTS: In 125 mg/kg STZ group, two rhesus monkeys died, in 8 hours following STZ administration, of serious hypoglycemia caused by severely damaged pancreas β cells; All rhesus monkeys in this group had got significantly increased liver transaminase, serum creatinine and urea nitrogen at week 1 following STZ administration, which reached a peak during 2-4 weeks; One rhesus monkey in this group showed severe shortage of endogenous trypsin and hyperglycemia irreversible by exogenous insulin following STZ administration, and finally died at day 13 following STZ administration due to the glucose metabolic disorder, ketoacidosis, liver and renal failure; The other two survivors in this group kept high level of liver transaminase,urea nitrogen and serum creatinine throughout the observation period. In 75 mg/kg STZ group, rhesus monkeys presented significantly increased liver transaminase, serum creatinine and urea nitrogen at week 1-2 following STZ administration; After 4 weeks following administration, their liver and renal function presented with abnormality of different degrees; One rhesus monkey in this group had got injured renal function, decreased power of resistance, eyelid edema, general dropsy and irreversible infected rump after injection of STZ, and finally died at the end of week 5 following administration; Another rhesus in this group presented with irreversible continuous hyperglycemia, inappetence and significantly decreased weight, and finally died ofsystemic failure at week 9 following administration. In the 50 mg/kg STZ group, renal function of monkeys were slightly affected, with a transient mild rise which return to the normal level by the end of week 4 following administration; Only 3 animals in this group appeared eyelid edema during 1-4 weeks following administration which disappeared afterwards.CONCLUSION: STZ of 50 mg/kg is possibly the optimal dose for inducing diabetes models in most rhesus monkeys.

Objective To evaluate the value of ultrasound elastography in the diagnosis of breast tumor ,and compared with imaging analysis .Methods To collect the image data of 160 patients ,confirmed by pathology ,a total of 182 ,preoperative ultra-sound elasticity imaging and DWI ,ultra sonic elastography diagnosis by five points method ,DWI on the basis of the measured ADC value in the diagnosis of lesions ,respectively compared with pathology .Results Ultrasound elastography diagnosis of 89 malignant tumors ,of which the correct diagnosis of 78 malignant tumors ,7 misdiagnosis ,11 benign misdiagnosed as malignant diagnosis;93 benign tumors ,86 of correct diagnosis ,11 misdiagnosis ,7 malignant misdiagnosed as benign ,sensitivity was 87 .6% ,specificity of 92 .5% ,the Accuracy was 93 .9% ;ultrasound elastography and DWI combined imaging diagnosis of 86 malignant tumors ,81 correct diagnosis of malignant tumors ,4 misdiagnosis ,5 from the benign misdiagnosed as malignant diagnosis ,96 benign tumors ,92 correct diagnosis ,5 misdiagnosis ,the sensitivity was 94 .1% ,specificity of 95 .8% ,the accuracy was 97 .2% .Conclusion Ultrasound elas-tography in breast benign and malignant tumor diagnosis with higher sensitivity and specificity ,accuracy ,joint DWI can significantly improve the sensitivity and specificity of breast benign and malignant tumor diagnosis ,accuracy .

Objective To investigate the diagnostic value of 3.0T MR high field high-b-value diffusion weighted imaging (DWI) in prostate cancer (PCa) and to analyze its correlation with Gleason classification.Methods A total of 78 cases proved by operation and pathology were collected,including 41 cases of benign prostatic hyperplasia(BPH) and 37 cases of PCa.PCa patients were classified according to postoperative pathological scores,and their correlation with ADC values was analyzed subsequently.Parameter scanning was performed in all patients by using Philps 3.0T MR with b value at 0 s/mm2,1 000 s/mm2 and 1 500 s/mm2.The signal intensity and ADC value of PCa and BPH were compared under two kinds of high-b-values,and the correlation between ADC value and Gleason classification was analyzed.Results It was found that the specificity and accuracy of T2WI combined with b value of 1 500 s/mm2 were higher than these of T2WI combined with b value of 1 000 s/mm2 for the diagnosis of PCa.The ranking result of ADC value corresponding to Gleason score of PCa after operation was:2-4 points ＞ 5-6 points ＞7 points ＞ 8-10 points.Besides,the ADC value of the corresponding lesion with b value of 1 500 s/mm2 was lower than that with b value of 1 000 s/mm2,and the difference was statistically significant (P＜0.05).Conclusion High field high-b-value DWI combined with T2WI is of high value in differential diagnosis of PCa and BPH,and the specificity and accuracy of PCa and BPH improve obviously with the increase of the b value.Additionally,the ADC value is negatively correlated with the Gleason score.

Objective Evaluation of the efficacy of high-frequency repetitive transcranial magnetic stimulation for chronic disturbance of consciousness after severe craniocerebral injury based on magnetic resonance spectroscopy.Methods The clinical data of 106 patients with chronic disturbance of consciousness after severe craniocerebral injury from January 2018 to December 2022 were retrospectively analyzed,and they were divided into control group(conventional rehabilitation treatment)and observation group(high frequency repetitive transcranial magnetic stimulation treatment)by propensity score matching method(1∶1),with 53 cases in each group.Both groups were examined by magnetic resonance spectroscopy(MRS)before and after treatment.The brain metabolic indexes[N-acetyl aspartate(NAA)/creatine(Cr)value,choline complex(Cho)/Cr value],Glasgow coma scale(GCS)score,electroencephalogram(EEG)grading,coma recovery scale(CRS-R)score,brainstem auditory evoked potential(BAEP)grading,upper limb sensory evoked potential(SSEP)grading and Cerebral blood flow perfusion index[cerebral blood volume(CBV),mean transit time(MTT),cerebral blood flow(CBF)]were compared between the two groups.Results After treatment,the NAA/Cr values of the thalamus and brainstem in the two groups increased,while the Cho/Cr values decreased,and the levels of brain metabolic indexes in the observation group were signifi-cantly better than those in the control group(P<0.05).The two groups'GCS score and CRS-R score increased,and the improvement of the observation group was better than that of the control group(P<0.05).The BAEP grading,EEG grading,and SSEP grading of the two groups improved,and those of the observation group were better than the control group(P<0.05).The CBF and CBV of the two groups increased,and MTT decreased,and the level of cere-bral blood perfusion index in the observation group was better than that in the control group(P<0.05).Conclusion High frequency repetitive transcranial magnetic stimulation has a significant effect on the recovery of patients with chronic consciousness disorders after severe craniocerebral injury.The mechanism may be related to improving the blood flow velocity of brain tissue and metabolism in the brain.