LONG‐TERM FOLLOW UP OF PATIENTS WITH SMALL GASTROINTESTINAL STROMAL TUMORS IN THE STOMACH USING ENDOSCOPIC ULTRASONOGRAPHY‐GUIDED FINE‐NEEDLE ASPIRATION BIOPSY

Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed.     

Responses of CDKs and p53 in Delayed Ischemic Neuronal Death

Stroke is a debilitating disease that affects millions each year.While in many cases cerebral ischemic in jury can be limited by effectivw resuscitation or thrombolytic treatment,the injured neurons wither in a process known as delayed neuronal death(DND).Mounting evidence indicates that DND is not simply necrosis played out in slow motion but apoptosis is triggered.Of particular interest are two groups of signal proteins that participate in apoptosis-cyclin dependent kinases(CDKs) and p53-among a myriad of signaling events after an ischemic insult.Recent investigations have shown that CDKs,a family of enzymes initially known for their role in cell cycle regulation,are activated in injured neurons in DND.As for p53,new reports suggest that its up-regulation may represent a failed attempt to rescue in jured neurons,although its up-regulation was previously considered an indication of apoptosis.These observations thus rekindle an old quest to identify new neuroprotective targets to minimize the stroke damage.In this review,the author will examine the evidence that indicates the participation of CDKs and p53 in DND and then introduce pre-clinical data to explore CDK inhibition as a potential neuroprotective target.Finally,using CDK inhibition as an example,this paper will discuss the pertinent criteria for a viable neuroprotective strategy for ischemic in jury.     

Reversal of diabetes in BB rats by transplantation of encapsulated pancreatic islets

Prolonged survival of pancreatic islet allografts implanted in diabetic BB rats was achieved by encapsulation of individual islets in a protective biocompatible alginate-polylysine-alginate membrane without immunosuppression. Intraperitoneal transplantation of the encapsulated islets reversed the diabetic state of the recipients within 3 days and maintained normoglycemia for 190 days. Normal body weight and urine volume were maintained during this period, and no cataracts were detected in the transplant recipients. In contrast, control rats receiving transplants of unencapsulated islets experienced normoglycemia for less than 2 wk. These results demonstrated that microencapsulation can protect allografted islets from both graft rejection and autoimmune destruction without immunosuppression in an animal model that mimics human insulin-dependent diabetes.     

Elimination of antibiotic-resistant plasmids by quinolone antibiotics

Of 7 plasmids we tested, the plasmid pORF2 was eliminated in vitro with the most efficiency by treatment with subinhibitory concentrations of novobiocin, coumermycin and 10 quinolones. It showed a cure rate of 43% by enoxacin; 12% by novobiocin, pefloxacin, ciprofloxacin and CI-934; 7% by coumermycin and ofloxacin; 9% by amifloxacin; and 4% by AM-833. On the other hand, pSC194, pBR322 and pMH612 were poorly cured in vitro by quinolones, except pSC194 which was cured 33% by enoxacin. R1, pP1603, and pUB110 were unaffected by the treatment. Mice were challenged intraperitoneally with a 2XLD50 of Escherichia coli carrying the ORF2 plasmid and were treated per os with 1 X or 1/2 X ED50 of either enoxacin or CI-934. The frequency of loss of ampicillin resistance determined 3 h after treatment shows curing effects of 92% for CI-934, 89% for enoxacin and 20% for untreated control.     

Delivery of therapeutic doses of doxorubicin to the mouse lung using lung-accumulating liposomes proves unsuccessful

Cancer Chemotherapy and Pharmacology - Addition of solid doxorubicin or solutions to pre-formed liposomes proved to be the optimal method for incorporating the drug into liposomes whilst...     

Serine hydroxymethyltransferase isoforms are differentially inhibited by leucovorin: characterization and comparison of recombinant zebrafish serine hydroxymethyltransferases.

Serine hydroxymethyltransferase (SHMT) provides activated one-carbon units required for the biosynthesis of nucleotides, protein, and methyl group by converting serine and tetrahydrofolate to glycine and N(5),N(10)-methylenetetrahydrofolate. It is postulated that SHMT activity is associated with the development of methotrexate resistance and the in vivo activity of SHMT is regulated by the binding of N(5)-CHO-THF, the rescue agent in high-dose methotrexate chemotherapy. The aim of this study is to advance our understanding of the folate-mediated one-carbon metabolism in zebrafish by characterizing zebrafish mitochondrial SHMT. The cDNA encoding zebrafish mitochondrial SHMT was cloned, overexpressed in Escherichia coli, and purified with a three-step purification protocol. Similarities in structural, physical, and kinetic properties were revealed between the recombinant zebrafish mitochondrial SHMT and its mammalian orthologs. Surprisingly, leucovorin significantly inhibits the aldol cleavage of serine catalyzed by zebrafish cytosolic SHMT but inhibits to a lesser extent the reaction catalyzed by the mitochondrial isozyme. This is, to our knowledge, the first report on zebrafish mitochondrial folate enzyme as well as the differential inhibition of leucovorin on these two SHMT isoforms. Western blot analysis revealed tissue-specific distribution with the highest enrichment present in liver for both cytosolic and mitochondrial SHMTs. Intracellular localization was confirmed by confocal microscopy for both mitochondrial and cytosolic SHMTs. Unexpectedly, the cytosolic isoform was observed in both nucleus and cytosol. Together with the previous report on zebrafish cytosolic SHMT, we suggest that zSHMTs can be used in in vitro assays for folate-related investigation and antifolate drug discovery.     

Changes in T .lymphocyte subsets after severe traumatic brain inJury

BACKGROUND： Besides local changes of cranial parenchymal cells, hemorrhage, etc., severe traumatic brain injuries also cause the changes of total body fluid and various functions, and the changes of lymphocytes and T lymphocyte subsets should be paid more attention to. OBJECTIVE： To reveal the changing laws of T lymphocyte subsets after severe traumatic brain injury, and compare with mild to moderate brain injury. DESIGN： A comparative observation. SETTINGS： Department of Neurosurgery, Longgang District Buji People＇s Hospital of Shenzhen City; Central Laboratory of Shenzhen Hospital of Prevention and Cure for Chronic Disease. PARTICIPANTS： All the subjects were selected from the Department of Neurosurgery, Longgang District Buji People＇s Hospital of Shenzhen City from August 2002 to August 2005. Thirty patients with severe brain injury, whose Glasgow coma score （GCS） was ≤ 8 points, were taken as the experimental group, including 21 males and 9 females, aging 16 - 62 years. Meanwhile, 30 patients with mild traumatic brain injury were taken as the control group （GCS ranged 14- 15 points）, including 18 males and 12 females, aging 15 -58 years. All the subjects were in admission at 6 hours after injury, without disease of major organs before injury Informed consents were obtained from all the patients or their relatives. METHODS： （1） The T lymphocytes and the subsets in peripheral blood were detected with immunofluorescent tricolor flow cytometry at l, 3, 7 and 14 days after injury in both groups. （2） The conditions of pulmonary infections were observed at 4 days after injury. The differences of measurement data were compared with the t test. MAIN OUTCOME MEASURES： Changes of T lymphocytes subsets at 1 - 14 days after severe and mild or moderate traumatic injury. RESULTS： Finally, 28 and 25 patients with mild to moderate traumatic brain injury, whereas 25 and 21 patients with severe traumatic brain injury were analyzed at 7 and 14 days respectively, and the missed ones died due to the development of disease. （1） Changes of T lymphocyte subsets： At 1 and 3 days after injury, CD3, CD4, CD8, CD4/CD8 began to decrease, whereas CD8 increased in the experimental group, which were very significantly different from those in the control group （t =2.77 - 3.26, P 〈 0.01）, and began to recover at 7 days, which were significantly different from those in the control group （t = 2.06 - 2.24, P 〈 0.05）, and generally recovered to the normal levels at 14 days （P 〉 0.05）. （2） Conditions of pulmonary infections： At 4 days after injury, the rate of pulmonary infection was significantly different between the experimental group and control group [73% （22/30）, 0, x2=37.29, P 〈 0.01]. CONCLUSION： Patients with severe traumatic brain injury suffer from damages of cellular immune function at early period （within 7 days）, and they are easily to be accompanied by pulmonary infections.     

一种较好的RNA分离制备方法及其在人胚RNA提取中的应用

以钒基核苷酸复合物为核酸酶抑制剂,从人胚组织中制备总RNA,所得产品几乎不含DNA和蛋白质,经过分离Poly(A)~ mRNA,证明制品有合成cDNA的完整功能,方法比较简捷,适于大量制备以满足分离mRNA 之需,并讨论了此法的优缺点。