An experimental study onO-[18F]fluoromethyl-L-tyrosine for differentiation between tumor and inflammatory tissues

OBJECTIVE: O-[18F]fluoromethyl-L-tyrosine (18F-FMT) is a recently developed tumor-detecting agent with simple preparation and high radiochemical yields. The aim of this study was to assess the potency of 18F-FMT for differentiating tumor and inflammatory tissues using an animal model with an implanted tumor and experimentally induced inflammatory foci. METHODS: An ascites hepatoma cell line, AH109A, turpentine oil and Staphylococcus aureus were inoculated subcutaneously into Donryu rats as a tumor model, aseptic inflammation model and bacterial infection model, respectively. The biodistribution of radioactivity was assessed in rats at 5, 10, 30, 60, and 120 min after injection with 18F-FMT. Dual tracer whole-body and macro autoradiographies were performed 60 min after injection with a mixture of 18F-FMT and 2-deoxy-D-[1-14C]glucose (14C-DG). RESULTS: Tumor uptake of 18F-FMT was on average 1.27% injected dose per gram of tissue (%ID/g) and 1.43% ID/g at 30 min and 60 min, respectively and significantly higher than that in other normal tissues, except the pancreas (3.48% ID/g at 60 min). The uptakes in the aseptic and bacterial inflammatory tissues were very low and were not different from those of the background tissues. Dual tracer whole-body and macro autoradiographic studies showed that tumor uptake of 18F-FMT was clearly higher than uptake by the other tissues, while 18F-FMT accumulated much less both in aseptic and bacterial inflammatory tissues. In contrast, the 14C-DG images showed high accumulations not only in tumors but also in aseptic and bacterial inflammatory tissues. CONCLUSION: 18F-FMT seems to be a promissing tracer for the differentiation between tumor and inflammation because of higher specificity to tumor.     

Primary source of income is associated with differences in HIV risk behaviors in street-recruited samples

Background  

The relationship between primary source of income and HIV risk behaviors and the racial/ethnic differences in risk behavior profiles among disadvantaged populations have not been fully explored. This is unusual given that the phenomenon of higher risk in more disadvantaged populations is well-known but the mechanisms remain unclear. We examined the relationship between primary source of income and differences in HIV risk behaviors among four racial/ethnic groups in the southern United States.     

The relation between deoxycytidine kinase activity and the radiosensitising effect of gemcitabine in eight different human tumour cell lines

Background  

Gemcitabine (dFdC) is an active antitumour agent with radiosensitising properties, shown both in preclinical and clinical studies. In the present study, the relation between deoxycytidine kinase (dCK) activity and the radiosensitising effect of gemcitabine was investigated in eight different human tumour cell lines.     

Popliteal cysts and deep venous thrombosis: Tc-99m red blood cell venography

Thirty-four patients who clinically were suspected of having deep venous thrombosis (DVT) underwent Tc-99m red blood cell (RBC) venography followed by contrast venography. The sensitivity (88%) and specificity (94%) of Tc-99m RBC venography for DVT confirmed findings of previous studies. Twenty-four patients who had proved popliteal cysts and swollen calves also were examined using Tc-99m RBC venography. Large cysts (greater than 9 X 4 X 4 cm) showed lack of DVT features, photon deficient cold areas in the popliteal fossa, and diversion of venous flow around the photon deficient area. These features were seen in 25% of the study population (six patients), and assisted in the distinction between the two conditions.     

RELATIONSHIP BETWEEN MUTABILITY,POLARITY AND EXTERIORITY OF AMINO ACID RESIDUES IN PROTEIN EVOLUTION

A systematic study was carried out on mutability of amino acid residues in evolving proteins in relation to their polarity and location within three-dimensional structure of proteins. Exteriority of residue sites is quantitatively defined as accessibility based on their static accessible surface area to solvent water molecule. Residue sites are classified into interior and exterior depending on their accessibility. More frequent substitution on exterior sites is confirmed to be general in eight sets of homologous protein families regardless of their biological functions and of presence or absence of a prosthetic group. Virtually all types of amino acid residues are found to have higher mutabilities on the exterior than in the interior. No correlation between mutability and polarity was observed of amino acid residues in the interior and on the exterior, respectively. Amino acid residues are classified into three depending on their polarity, polar (Arg, Lys, His, Gln, Asn, Asp and Glu), weak polar (Ala, Pro, Gly, Thr and Ser) and nonpolar (Cys, Val, Met, Ile, Leu, Phe, Tyr and Trp). Amino acid replacements during protein evolution are very conservative; 88% and 76% of them in the interior and on the exterior, respectively, are within the same group of the three. Inter-group replacements are such that weak polar residues are replaced more often by nonpolar residues in the interior and more often by polar residues on the exterior.     

Intermittent Ventricular Bigeminy as an Expression of Two-Level Wenckebach Periodicity in the Reentrant Pathway of Extrasystoles

A patient with intermittent ventricular bigeminy is reported in whom the presence of two-level Wenckebach periodicity in the reentrant pathway of extra-systoles is suggested. When sinus arrest was caused by vagal stimulation, no ectopic QRS complex occurred. This indicated that ventricular bigeminy was not parasystolic bigeminy but ordinary extrasystolic bigeminy. Observations of the electrocardiogram suggested that Wenckebach block occurred at two different levels in the reentrant pathway of ventricular extrasystoles. When extrasystoles were noninterpolated, Wenckebach block occurred at the distal level of the pathway and caused termination of ventricular bigeminy. On the other hand, when extrasystoles were interpolated, Wenckebach block occurred at the proximal level of the pathway. This is the first report to suggest the presence of two-level Wenckebach periodicity in a reentrant pathway of extrasystoles.     

氮化钛纳米膜对磁性附着体铁铬钼合金磁力影响的研究

目的研究应用离子束辅助沉积制备氮化钛薄膜后,对磁性附着体磁力的影响.方法应用电子拉伸机测量镀膜前后磁性附着体磁力大小.结果镀膜前后磁性附着体磁力无明显改变,统计学分析无显著性差异(P>0.05).结论磁性附着体铁铬钼合金经表面镀膜后,磁力无改变.可以应用离子束辅助沉积技术对磁性附着体进行表面处理.     

Ganglion cells in Ewing's sarcoma following chemotherapy: A case report

A case of Ewing's sarcoma of the bone, arising in the right radius of a 12-year-old girl, which showed unique histologic features after pre-operative treatment, is reported. The light microscopic features of a biopsy sample were those of a small round cell tumor showing positive immunoreaction with antibodies against the product of the MIC 2 gene (O13), neuron-specific enolase, neurofilament, and synaptophysin, but no morphological differentiation. The patient received combined intensive multi drug chemotherapy and radiation before surgery. Examination of the surgical specimen showed that the tumor was less cellular than that in the biopsy specimen, and was composed mainly of loosely textured large cells mimicking ganglion cells, occasionally forming Homer-Wright rosettes. An lmmunohistochemical study revealed that neural differentiation was enhanced. Immunoreactivity for Leu-7 also became positive. Although the patient underwent postoperative chemotherapy, she died of multiple lung and bone metastases 30 months alter the diagnosis. Autopsy showed that metastatic foci were made up of densely packed small round cells like those seen In the biopsy samples, but associated with prominent Homer-Wright rosettes. To the authors' knowledge, this is the first report of a tumor being replaced almost entirely by ganglion cells after preoperative chemotherapy and radiotherapy.     

肥胖儿童心血管疾病的危险因素

营养过剩所致的儿童肥胖症已成为十分常见的营养问题。本文对上海市五角场地区８８０２名４－１２岁儿童进行了单纯性肥胖症的筛查及有关调查。