[Demonstration of the presence of Methanobrevibacter in a colon cancer Chinese patient]

A fecal specimen from a Chinese patient (85-year-old man) suffering from colonic cancer was examined for the presence of methane-producing bacteria. As a result, a Methanobrevibacter organism was isolated. Our isolate did not grow in the presence of bile salts, a result different from Methanobrevibacter from healthy Americans' feces by Miller et al.

[Study on conversion of RARalpha/PML fusion gene in acute promyelocytic leukemia]

OBJECTIVE

To analyze the conversion of RARalpha/PML gene in acute promyelocytic leukemia (APL) patients before and after treatment with all-trans retinoic acid (ATRA) followed by intensive consolidation chemotherapy (ICC) and allogeneic bone marrow transplantation (allo-BMT).

METHODS

RARalpha/ PML fusion gene was detected in 22 APL patients before and after treatment by reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

RARalpha/PML fusion gene was positive in 75% of the patients after achieving complete remission with ATRA, and turned negative in 83% of the patients after ICC. The durations of conversion to the RT-PCR negative status varied from 1 to 39 months. Ten patients received allo-BMT, and all of them were RARalpha/PML fusion gene negative in 4 months post allo-BMT.

CONCLUSION

APL patients could achieve biological remission after ICC and allo-BMT, and the latter seemed to eliminate residual leukemic cells sooner in vivo than the former did.

Expression of PTEN and survivin in cervical cancer: promising biological markers for early diagnosis and prognostic evaluation

This study aims to evaluate the expression of the antioncogene phosphatase and tensin (PTEN) homologue and survivin, a protein encoded by the anti-apoptotic gene baculoviral inhibitor of apoptosis repeat containing 5 (BIRC5), in the progression of cervical neoplasia and to elucidate the relationship between PTEN and survivin expression based on clinicopathological features in squamous cell carcinoma of the uterine cervix. A total of 20 patients with cervical ectropion and squamous metaplasia, 30 with cervical intraepithelial neoplasia, and 49 with cervical squamous cell carcinoma were enrolled in the study. Immunohistochemical staining was performed to detect PTEN and survivin expression in each group. Normal cervical epithelium from 10 people served as the control. Results showed that PTEN expression progressively decreased with the continuum from normal epithelium to squamous cell carcinoma (P < 0.05), whereas survivin expression progressively increased (P < 0.05). Furthermore, positive PTEN immunostaining was associated with clinical stage and tumour size (P < 0.05). The level of PTEN expression in the metastatic pelvic lymph node group was significantly lower compared with the non-metastatic pelvic lymph node group (P < 0.01). Positive PTEN immunostaining was not associated with age or degree of differentiation (P > 0.05). Positive survivin immunostaining was associated with clinical stage and tumour size (P < 0.05). Survivin-positive expression in the metastatic pelvic lymph node group was significantly higher compared with the nonmetastatic pelvic lymph node group (P < 0.01). No obvious relationship was found between survivin expression and patient age (P > 0.05). PTEN expression negatively correlated with survivin expression in cervical intraepithelial neoplasia and cervical squamous cell carcinoma (P < 0.01). PTEN and survivin expression correlated with incidence and progression of uterine cervical cancer. Positive expression levels of PTEN and survivin provide potential evaluation indices for early diagnosis and prognosis of uterine cervical cancer, and these biomarkers are also potentially promising therapeutic targets.

Transduction of primitive human marrow and cord blood-derived hematopoietic progenitor cells with adeno-associated virus vectors

We evaluated the capacity of adeno-associated virus (AAV) vectors to transduce primitive human myeloid progenitor cells derived from marrow and cord blood in long-term cultures and long-term culture-initiating cell (LTC-IC) assays. Single-colony analyses showed that AAV vectors transduced CD34(+) and CD34(+)38(-) clonogenic cells in long-term culture. Gene transfer was readily observed in LTC-ICs derived from 5-, 8-, and 10-week cultures. Recombinant AAV (rAAV) transduction was observed in every donor analyzed, although a wide range of gene transfer frequencies (5% to 100%) was noted. AAV transduction of LTC-ICs was stable, with week-8 and -10 LTC-ICs showing comparable or better transduction relative to week-5 LTC-ICs. Fluorescence in situ hybridization (FISH) analyses performed to determine the fate of AAV vectors in transduced cells showed that 9% to 28% of CD34(+) and CD34(+)38(-) cells showed stable vector integration as evidenced by chromosome-associated signals in metaphase spreads. Comparisons of interphase and metaphase FISH suggested that a fraction of cells also contained episomal vector at early time points after transduction. Despite the apparent loss of the episomal forms with continued culture, the number of metaphases containing integrated vector genomes remained stable long term. Transgene transcription and placental alkaline phosphatase (PLAP) expression was observed in CD34(+), CD34(+)38(-) LTC-ICs in the absence of selective pressure. These results suggest that primitive myeloid progenitors are amenable to genetic modification with AAV vectors.

Study on hydroxyapatite-coated titanium implants used as orthodontic anchorage--an experimental investigation of implant stability and peri-implant neck tissue in dogs

OBJECTIVE

Hydroxyapatite-coated titanium endosseous implants as orthodontic anchorage were studied.

METHODS

These implants, installed in the mandibles of two dogs, were loaded with the orthodontic force of 150 g for 3 months. The stability of the implant and peri-implant neck tissue were investigated with radiograph and index evaluation.

RESULTS

No implants were mobile, loosened or dislocated at the 3-month follow-up. The soft tissue around the cervical part of the implants had slight inflammation because of poor oral hygiene and stimulation of residual foods attached to the stainless steel spring. However, no resorption of marginal alveolar bone was found under sustained orthodontic force.

CONCLUSIONS

The HA-coated titanium implant can be used as anchorage for short-term orthodontic treatment.

[The examination of SIgE in perennial allergic rhinitis with mast allergy test system]

OBJECTIVE

To explore the relation between serum specificity immunoglobulin E (SIgE) and skin test (intracutaneous test) as well as nasal provocation in Perennial allergy rhinitis (PAR) by Mast Allergy Test System.

METHOD

Serum allergen-specific IgE (SIgE) were examined by Mast Allergy Test System in 57 case of PAR patients.

RESULT

The SIgE positive rate of fannae and pteronvssinus are highest (52.6%), the sensitive rate of intracutaneous test is 88.4% and nasal provocation is 88.9%. The SIgE positive rates of cludosporium, penicillum and altemana are 26.3%, 24.6% and 21.0%, respectively. The SIgE positive rates of fannae, cockroach, shrimp, crab, egg and milk is direct proportion with intracutaneous test (P < 0.01). Pteronvssiaus and pigweek mix have no relationship with intracutaneous test (P > 0.05). In addition, the positive rate of ragweed mix SIgE is 22.8%, but there is non of this plant in South China. It is worthy of paying attention in clinic.

CONCLUSION

It indicate that Mast Allergy Test System is one of the better examination for PAR allergens.

[Preparation of monoclonal antibodies against malaria through immunization of mice with recombinant plasmid DNA]

BALB/c mice were immunized by injection of recombinant plasmid DNA carrying MSP1-31 fragment of Plasmodium falciparum. After antiserum was induced, McAbs were prepared by fusing SP2/0 myeloma cells with spleen cells. Specific McAbs were detected in hybridoma culture supernatant and mouse ascites by ELISA, positive hybridomas were cloned by technique of limiting dilutions. Two McAbs, 9H9 and 8A2, against the malaria protein were produced and characterized. The titers of the two McAbs in acites were 1:10,000 and 1:2500 respectively. The Ig subclass of these McAbs was IgG1. Western blot test showed that the McAb specifically reacted with MSP1-31 antigen. These results proved that monoclonal antibodies could be produced by use of immunization of mice with plasmid DNA or DNA vaccine.

Report from the Chinese Bone Marrow Transplant Registry with special regard to autologous transplant

OBJECTIVE

To study the current status of autotransplantation in the People's Republic of China and facilitate national and international exchange of relevant experiences.

METHODS

On the basis of the materials collected from the member units around our country, various statistical methods, such as Kaplan-Meier and chi 2 tests, were used to estimate the probabilities of leukemia free survival (LFS).

RESULTS

Up to July 31, 1996, a total of 1213 cases of stem cell transplantation (SCT) were performed in 61 medical units in the People's Republic of China, and 22 of the units are able to perform both allogeneic SCT (Allo-SCT) and autologous-SCT (ASCT). The remaining 41 units had the capacity only to perform autologous-SCT. There were 772 cases of autologous SCT performed. The three year probabilities of leukemia free survival for acute mylogeneous leukemia complete remission (AML-CR1) and acute lymphocyte leukemia complete remission (ALL-CR1) recipients were 56% and 42.8%, respectively. The three year probabilities of relapse were 44.8% and 47%, respectively. Among the patients with acute leukemia who attained CR1 within 40 days of diagnosis and who subsequently underwent autotransplantation within three to six months, the three year probabilities of LFS for acute mylogenous leukemia (AML) and acute lymphocyte leukemia (ALL) were 72% and 50%, respectively.

CONCLUSIONS

Patients who attained complete remission (CR1) within 40 days after diagnosis and underwent subsequent autologous-SCT within three to six months of CR1 enjoyed a significantly increased LFS.

Complete inhibition of vascular endothelial growth factor (VEGF) activities with a bifunctional diabody directed against both VEGF kinase receptors, fms-like tyrosine kinase receptor and kinase insert domain-containing receptor

Vascular endothelial growth factor (VEGF) binds to and mediates its activity mainly through two tyrosine kinase receptors, VEGF receptor 1 [or fms-like tyrosine kinase receptor (Flt-1)] and VEGF receptor 2 [or kinase insert domain-containing receptor (KDR)]. Numerous studies have shown that overexpression of VEGF and its receptor plays an important role in tumor-associated angiogenesis and hence in both tumor growth and metastasis. We demonstrated previously that antagonistic antibodies to KDR specifically inhibited VEGF-stimulated receptor activation, cell migration, and endothelial cell mitogenesis. Here we constructed a recombinant bifunctional diabody that is capable of blocking both Flt-1 and KDR from binding to their ligands, including VEGF and placenta growth factor (PlGF). The diabody was expressed in Escherichia coli and purified by single-step affinity chromatography. The diabody retained the capacity to bind both KDR and Flt-1 and effectively blocked interaction between KDR and VEGF, Flt-1 and VEGF, and Flt-1 and PlGF. Furthermore, the diabody is a stronger inhibitor than its parent antibodies to VEGF-stimulated mitogenesis of human endothelial cells, as well as both VEGF- and PlGF-induced migration of human leukemia cells. Taken together, our results suggest that dual receptor blockade with the bifunctional diabody may prove to be a more efficient approach in inhibiting VEGF-stimulated angiogenesis.

[Detection of minimal residual disease after allogeneic bone marrow transplantation in chronic myeloid leukemia]

OBJECTIVE

To detect minimal residual disease (MRD) after allogeneic bone marrow transplantation (allo-BMT) in chronic myeloid leukemia (CML).

METHODS

M-bcr/abl mRNA was assayed by reverse transcriptase polymerase chain reaction (RT-PCR) in bone marrow cells from 46 successfully sibling marrow engrafted CML patients.

RESULTS

About 70% of the patients achieved genetic complete remission in 3 months post allo-BMT. Four patients were M-bcr/abc mRNA positive at 1.5 to 2 months post allo-BMT and turned to be negative at 3 to 9 months post allo-BMT. One patient was still M-bcr/abl(+) after disease-free survival(DFS) for more than 6 years, while another one was M-bcr/abl(-) after DFS for more than 4 years.

CONCLUSION

RT-PCR is so far the most sensitive method for MRD detection in CML, but its limitation should not be ignored.

A high precision flat crystal spectrometer compatible for ultra-high vacuum light source

We report on a flat crystal spectrometer (FCS) featuring a differently pumped rotary feedthrough and double detectors connected to a crystal chamber by extendable bellows built at the Shanghai EBIT Laboratory. It was designed to overcome defects such as oil contamination, little distance from the detector to the crystal and others of an early FCS equipped at the same laboratory, but still keeps a large detectable angle range of detectors and brings new features and functions such as the Bond method measurement and double-crystal measurement which are based on the two-detector and large bellow design. This new FCS could cover an energy range of measurable photons from 570 eV to 10 keV and reach a vacuum better than 6 × 10^-10 Torr and thus is compatible for coupling directly to ultra-high vacuum light sources. Off-line tests of the FCS were undertaken where Kα x-rays from solid titanium were measured and analyzed. Measurements of transitions in He-like argon ions were performed when the spectrometer was directly connected to Shanghai EBIT, and the width of the x-ray source was monitored simultaneously using an x-ray slit imaging system. An observed spectral line broadening was 0.869 eV corresponding to a resolving power of 3600, including Doppler broadening of the x-ray source. Taking account of the measured source width, we made simulations using the SHADOW 3 code and got a nominal resolving power of 6500 for the spectrometer. This high nominal resolving power is due to a longer distance from the crystal to the detector, comparing with that in the early FCS.

Interaction between intercalation type anticancer drugs and DNA studied by ultraviolet resonance Raman spectroscopy

The interaction of typical intercalation type anticancer drugs, adriamycin (ADM) and aclacinomycin (ACM), with calf thymus DNA was studied first with ultraviolet resonance Raman spectroscopy (UVRRS). The results demonstrate that the important information such as intercalation sites of drugs, the electronic interaction and the hydrogen bonds between drugs and DNA can be obtained by UVRRS. The method can also show the influence of drugs on DNA conformation and hydrogen bonds between bases of DNA.

[Chemical constituents of Rhodiola kirilowii (Reg.) Reg]

Three compounds were isolated from the water-soluble part of alcohol extracts of rhizomes of Rhodiola kirilowii. Two of them were identified as salidroside and tyrosol, respectively by chemical and spectral analysis. beta-sitosterol was obtained from the petroleum extracts of the plant.

[In vitro study on transduction of human O(6)-methylguanine-DNA-methyltransferase cDNA into human umbilical cord blood CD34(+) cells]

OBJECTIVE

To explore human umbilical cord blood hematopoietic progenitor cells transduced with human O(6)-methylguanine-DNA-methyltransferase (MGMT) gene increase resistance to 1,3-Bis(2-Chloroethyl)-1-Nitrosourea(BCNU).

METHODS

The present authors obtained a full length cDNA fragment encoding the human MGMT from a patient with cholelithiasis liver tissue by RT-PCR method and confirmed by DNA sequencing. The fragment was cloned into pGEM-T vector and further subcloned into G1Na retrovirus vector. Then the G1Na-MGMT was transfected into the packaging cell lines GP+E86 and PA317 by LipofectAMINE method; using the medium containing BCNU for cloning selection and ping-ponging supernatant infection between ecotropic producer clone and amphotropic producer clone, the authors obtained high titer amphotropic PA317 producer clone with the highest titer up to 1.6x10(6) CFU/ml. Cord blood CD34(+) cell were transfected repeatedly with supernatant of retrovirus containing human MGMT cDNA under stimulation of hemopoietic growth factors.

RESULTS

PCR, RT-PCR, Southern blot, Northern blot, Western blot and MTT analyses showed that MGMT gene had been integrated into the genomic DNA of cord blood CD34(+) cells and expressed efficiently in the transfected cells. The transgene recipient cells conferred 4 folds stronger resistance to BCNU than that of the non-transduced.

CONCLUSION

The retrovirus vector-mediated transfer of MGMT drug resistance gene into human cord blood CD34(+) cells and expression could confer the resistance of transgene cells to BCNU toxicity.

[A clinico-pathological study of granulomatous amoebic encephalitis]

OBJECTIVE

To study the clinico-pathological characteristics and differential diagnosis of granulomatous meningioencephalitis caused by acanthamoeba.

METHODS

The clinical features, CT scan findings and post mortem pathological changes of 3 patients afflicted with granulomatous amoebic encephalitis (GAE) were analysed.

RESULTS

GAE is a chronic clinical entity. Clinical manifestations include headache, low fever, seizures, hemiparesis and coma leading to death. CSF: pressure slightly elevated with presence of lymphocytes and plasma cells, glucose usually low with moderately high protein levels. CT scans were non specific. Clinical course insidious and may mimic bacterial meningitis or tuberculous meningitis. Post mortem pathological examinations showed that acanthamoeba produced a chronic or subacute granulomatous meningioencephalitis. Acanthamoebic trophoziotes and cysts were found within the hemorrhagic necrotic cerebral tissues. In some cases there is severe angitis and fibrinoid necrosis of the vascular wall with perivascular cuffing by lymphocytes and plasma cells. Trophozoites and cysts were found within the perivascular space.

CONCLUSIONS

Acanthamoeba is an opportunistic pathogenic free living amoeba which can produce fatal GAE.