[Different susceptibility of cell lines to thymidine kinase/ganciclovir-mediated killing effect and the way of cell death]

OBJECTIVE

To investigate the mechanism of variability of herpes simplex virus (HSV) thymidine kinase (TK)/ganciclovir (GCV)-mediated suicide effect obtained in three different cell lines and the ways in which this system-mediated cell killing occurs.

METHODS

Recombinant retroviral vector expressing HSV-TK was transduced into three cell lines known with different growth rate (PC-2, PC-7 and LLC-PK1). The doubling time of the transduced and parental cells was calculated. MTT method was used to detect the concentration of GCV at which cell growth was inhibited by 50% (IC(50) value). Cell cycle was analyzed by flow cytometry. Necrosis or apoptosis of cultured cells and/or xenografts was observed under light and electron microscope, and by in situ apoptosis detection.

RESULTS

The doubling time of the three parental cell lines was (31.2 +/- 0.1) h, (48.3 +/- 0.1) h, and (53.9 +/- 0.1) h, separately. The IC(50) values of their HSV-TK-transduced cell lines to GCV were (0.73 +/- 0.12) micromol/L, (0.93 +/- 0.16) micromol/L and (1.22 +/- 0.06) micromol/L, respectively and the IC(50) value was correlated with the cell doubling time. Flow cytometry revealed S arrest. The majority of cells under treatment of GCV displayed swelling and collapse, but very few cells showed apoptosis. Large areas of necrosis were observed in the xenografts.

CONCLUSIONS

The cells with high growth rate are more susceptible to HSV-TK/GCV-mediated killing effect. Necrosis is the main way in which cells of the three HSV-TK-transduced cells lines die.

The Nicolas Andry award. The pathogenesis and prevention of steroid-induced osteonecrosis

The effects of steroids on a cloned pluripotential cell from bone marrow stroma were examined in vitro in culture and in vivo after the cells were transfected with a traceable gene and transplanted into host mice. Bipedal chickens were treated with steroids to establish a model for osteonecrosis. The effects of a lipid lowering agent, lovastatin, on the prevention of steroid induced adipogenesis in vitro in cell culture, and on adipogenesis and osteonecrosis in vivo in chickens, were evaluated. On treatment with dexamethasone, cloned pluripotential cells began to differentiate into adipocytes and expressed a fat specific gene, whereas the expression of Type I collagen and osteocalcin messenger ribonucleic acid decreased. Addition of lovastatin in culture inhibited steroid induced fat gene expression and counteracted the inhibitory effect of steroids on osteoblastic gene expression. Cloned pluripotential cells were transduced with a traceable retrovirus vector encoding the beta-galactosidase and neomycin resistance genes. The transfected cells were administered to mice either by tail vein or by direct intramedullary injection. Half of the animals in each group were treated with steroids. Histologic sections showed the appearance of transplanted cells in the marrow. Analysis of marrow blowouts by flow cytometry revealed that steroid treatment produced adipogenesis in transplanted cells. Evidence of osteonecrosis was observed in steroid treated chickens, whereas sections from animals treated with steroids and lovastatin showed less adipogenesis and no bone death. The results indicate that steroid induced adipogenesis in the marrow may contribute to osteonecrosis and that lovastatin may be helpful in preventing the development of steroid induced osteonecrosis.

[The mechanism of bystander effect in herpes simplex virus thymidine kinase/ganciclovir-mediated gene therapy]

OBJECTIVE

To study the mechanism of bystander effect in herpes simplex virus thymidine kinase (HSV-TK)/Ganciclovir (GCV)-mediated gene therapy.

METHODS

Recombinant retroviral vectors expressing HSV-TK and beta-Galactosidase (Lac Z) genes were constructed and transferred into pancreatic carcinoma cell line respectively. Cell counting was used to detect the growth inhibition rate of HSV-TK-transduced cells in presence of GCV. Taking Lac Z-transduced cells as bystander cells, the bystander effect was detected by MTT method, and its mechanism was studied by the experiments of supernatant shifting, Verapamil inhibition and ultrastructural observation.

RESULTS

The growth inhibition rate of the HSV-TK-transduced cells in the presence of GCV was 92.1%, which was obviously 4.9% and 3.2% higher than of the non-and control vector-transduced cells. Mixed cells containing only 10% of HSV-TK-transduced cells showed 39.0% reduction of the proliferation, which meant there was an obvious bystander effect in the system. However this effect disappeared when transferring GCV-containing supernatant of HSV-TK-transduced cells to the parent cells and could be reduced significantly when verapamil was added in the medium, indicating that this bystander effect requires cell-cell contact. Gap junctions were observed existing between PC-2 cells by electron microscopy.

CONCLUSION

The bystander effect in HSV-TK/GCV-mediated gene therapy occurs by transfer of GCV metabolite from cell to cell through gap junction.

[Specific activity of the promoter containing Myc-Max response elements in c-myc-overexpressing cells]

OBJECTIVE

To investigate the specific activity of a hybrid promoter which is constructed by replacing the third domain of herpes simplex virus (HSV) thymidine kinase (TK) promoter with the Myc-Max response elements.

METHODS

Myc-Max response elements were ligated with a third domain-deleted HSV-TK promoter by cloning and subcloning PCR products. Then a luciferase-expressing plasmid, in which the luciferase gene was put under the control of hybrid promoter, was constructed and transfected transiently into the cell lines which had been demonstrated to be c-myc over- or low-expressing by Northern blot hybridization. The luciferase activities in these cells were detected.

RESULTS

In c-myc over-expressing cells, the hybrid promoter (Mpr) led to high levels of (81,966 +/- 43,238) relative light units (RLUs) in PC-2 cells and (70,563 +/- 22,435) RLUs in PC-7 cells, which were 78- and 150-fold higher than those coming from the third domain-deleted TK promoter (Epr), and also 6.9- and 1.7-fold higher than the activities controlled by TK promoter. However, Mpr showed a very low activity in c-myc low-expressing cells, in which the luciferase activity was (431 +/- 73) RLUs, similar to (601 +/- 141) RLUs produced by Epr.

CONCLUSION

The activity of hybrid promoter, which is composed of Myc-Max response elements and the third domain-deleted TK promoter, possesses cell-type specificity for c-myc-overexpressing cells.

[The establishment of a human pancreatic mixed ductal-endocrine carcinoma cell line]

OBJECTIVE

Establishment of a human pancreatic mixed ductal-endocrine carcinoma cell line.

METHODS

A specimen of this type of cancer was obtained from a male patient at the head of pancreas. The tumor tissue was minced into pieces and inoculated subcutaneously in nude mice. With two successive subcutaneous implants, a piece of tumor tissue taken from the 2(nd) implanted neoplasm of a nude mouse was minced into minute tissue masses and inoculated in a media containing 10% fetal bovine serum.

RESULTS

Currently, it has been passed to the 55(th) passage. Cells of this cell line (PC-EN) kept simultaneously the morphologic patterns of a pancreatic ductal and endocrine tumor which were verified by histochemistry and immunohistochemistry assays. Some of the PC-EN cells showed presence of neuroendocrine granules by electron microscopy. The growth rate of this cell line was relatively low. Kakryotype analysis showed two cell populations with its major mode of chromosomes numbers as 48 in one, and 56 in the other. Study on K-ras gene demonstrated that PC-EN harbored a mutated codon 12. Several gastrointestinal hormones and CEA were detected in PC-EN cells and in the supra-cultured medium using radioimmunoassay.

CONCLUSIONS

The cellular and molecular biologic characteristics of PC-EN cells illustrated that this cell line preserved the morphology of a pancreatic ductal and endocrine tumor and possessed a special growth property, chromosome karyotype, and mutation of Ki-ras gene, but also showed a biologic exocrine and endocrine functions of the pancreas. The establishment of PC-EN cell line will provide a useful model in vitro for further investigating the cellular and molecular biology of exocrine and endocrine tumors of the pancreas.

Fatty marrow conversion of the proximal femoral metaphysis in osteonecrotic hips

To determine whether fatty marrow conversion of the proximal femoral metaphysis is related to osteonecrosis of the femoral head using a marrow conversion index ([signal intensity of the proximal femoral metaphysis/signal intensity of the greater trochanter] x 100 in T1 weighted magnetic resonance images), a case control study was conducted on 42 osteonecrotic hips in 28 patients. The 28 patients (42 osteonecrotic hips) were matched with 84 control patients (84 normal hips) for gender, age (5-year range), and time of presentation (1-year range). The marrow conversion index was measured in each hip studied. The index was 90.2% (standard deviation, 8.2%) in osteonecrotic hips and 75.1% (standard deviation, 9.1%) in matched controls. By conditional logistic regression, a 5% increase in the index was associated with 3.6 times increase of the odds ratio of osteonecrosis and a 10% increase with a 12.9 times increase of the odds ratio. The marrow conversion index, which reflects the ratio of fatty marrow conversion of the proximal femoral metaphysis to that of the greater trochanter measured on T1 weighted magnetic resonance images, is increased in osteonecrotic hips.

CNTF, not other trophic factors, promotes axonal regeneration of axotomized retinal ganglion cells in adult hamsters

PURPOSE

To investigate the in vivo effects of trophic factors on the axonal regeneration of axotomized retinal ganglion cells in adult hamsters.

METHODS

The left optic nerve was transected intracranially or intraorbitally, and a peripheral nerve graft was apposed or sutured to the axotomized optic nerve to enhance regeneration. Trophic factors were applied intravitreally every 5 days. Animals were allowed to survive for 3 or 4 weeks. Regenerating retinal ganglion cells (RGCs) were labeled by applying the dye Fluoro-Gold to the distal end of the peripheral nerve graft 3 days before the animals were killed.

RESULTS

Intravitreal application of ciliary neurotrophic factor substantially enhanced the regeneration of damaged axons into a sciatic nerve graft in both experimental conditions (intracranial and intraorbital optic nerve transections) but did not increase the survival of distally axotomized RGCs. Basic fibroblast growth factor and neurotrophins such as nerve growth factor, brain-derived neurotrophic factor, neurotrophin-3, and neurotrophin-4/5 failed to enhance axonal regeneration of distally axotomized RGCs.

CONCLUSIONS

Neurons of the adult central nervous system can regenerate in response to trophic supply after injury, and ciliary neurotrophic factor is at least one of the trophic factors that can promote axonal regeneration of axotomized RGCs.

[The killing effects of two prodrug sensitivity genes on human pancreatic carcinoma cells PC-2]

OBJECTIVE

To compare the killing effects of herpes simplex virus thymidine kinase (HSV-TK)/ganciclovir (GCV) system versus cytosine deaminase (CD)/5-fluorocytosine (5-FC) system on human pancreatic carcinoma PC-2 cells.

METHODS

Recombinant retroviral vectors expressing HSV-TK and CD genes were constructed and transduced into pancreatic carcinoma cell line. Prodrug sensitivity and IC50 values (concentration of drug at which cell growth is inhibited by 50%) of the transduced cells were measured by MTT method. The bystander effects in the two systems were also compared.

RESULTS

The IC50 value of HSV-TK-transduced cells to GCV was (1.06 +/- 0.12) micromol/L and 558-fold lower than parental PC-2 cells, while the IC50 value of CD-transduced cells to 5-FC.00 was (33.00 + 0.95) micromol/L and 258-fold lower than parental PC-2 cells. Mixed cells containing 10% of transduced cells showed 39% and 50.3% growth inhibition in TK/GCV and CD/5-FC systems respectively.

CONCLUSION

Both HSV-TK/GCV and CD/5-FC systems showed effective antitumor activity in vitro to pancreatic carcinoma PC-2 cells. The therapeutic index of HSV-TK/GCV system is higher, but its bystander effect is lower than that of CD/5-FC system.

Establishing human prostate cancer cell xenografts in bone: induction of osteoblastic reaction by prostate-specific antigen-producing tumors in athymic and SCID/bg mice using LNCaP and lineage-derived metastatic sublines

LNCaP lineage-derived human prostate cancer cell lines C4-2 and C4-2B4 acquire androgen independence and osseous metastatic potential in vivo. Using C4-2 and C4-2B4 the goals of the current investigation were 1) to establish an ideal bone xenograft model for prostate cancer cells in intact athymic or SCID/bg mice using an intraosseous route of tumor cell administration and 2) to compare prostate cancer metastasis by administering cells either through intravenous (i.v.) or intracardiac administration in athymic or SCID/bg mice. Subsequent to tumor cell administration, prostate cancer growth in the skeleton was assessed by radiographic bone density, serum prostate-specific antigen (PSA) levels, presence of hematogenous prostate cancer cells and histopathologic evaluation of tumor specimens in the lymph node and skeleton. Our results show that whereas LNCaP cells injected intracardially failed to develop metastasis, C4-2 cells injected similarly had the highest metastatic capability in SCID/bg mice. Retroperitoneal and mediastinal lymph node metastases were noted in 3/7 animals, whereas 2/7 animals developed osteoblastic spine metastases. Intracardiac injection of C4-2 in athymic hosts produced spinal metastases in 1/5 animals at 8-12 weeks post-injection; PC-3 injected intracardially also metastasized to the bone but yielded osteolytic responses. Intravenous injection of either LNCaP or C4-2 failed to establish tumor colonies. Intrailiac injection of C4-2 but not LNCaP nor C4-2B4 cells in athymic mice established rapidly growing tumors in 4/8 animals at 2-7 weeks after inoculation. Intrafemoral injection of C4-2 (9/16) and C4-2B4 (5/18) but not LNCaP (0/13) cells resulted in the development of osteoblastic bone lesions in athymic mice (mean: 6 weeks, range: 3-12 weeks). In SCID/bg mice, intrafemoral injection of LNCaP (6/8), C4-2 (8/8) and C4-2B4 (8/8) cells formed PSA-producing, osteoblastic tumors in the bone marrow space within 3-5 weeks after tumor cell inoculation. A stepwise increase of serum PSA was detected in all animals. Reverse transcription-polymerase chain reaction (RT-PCR) to detect hematogenously disseminated prostate cancer cells could not be correlated to either serum PSA level or histological evidence of tumor cells in the marrow space. We have thus established a PSA-producing and osteoblastic human prostate cancer xenograft model in mice.

[The correlation between Burkitt's lymphoma and Epstein-Barr virus in 28 cases and their expression of p53 and bcl-2 proteins]

OBJECTIVE

To investigate the correlation between Burkitt's lymphoma and Epstein-Barr (EB) virus and its expression of p53 and bcl-2 proteins.

METHODS

Polymerase chain reaction (PCR), in situ PCR and immunohistochemical techniques were applied to specimens from 28 cases of Burkitt's lymphomas on paraffin-embedded sections.

RESULTS

EB virus was found in 8 (28.5%) cases by PCR, of which 3 were positive by in situ PCR. Positive rates for the expression of p53 and bcl-2 were 44.4% and 48.1% respectively. Whereas in stages I-II and III-IV, they were 3(23.0%), 9(64.2%) and 3(23.0%), 10(71.4%) respectively. Both the expression of p53 and bcl-2 were high in stages III-IV, low in stages I-II (P < 0.05). The positive cases of EB virus in combination with the expression of p53 and bcl-2 protein, p53 protein and bcl-2 protein were 4,5,4 respectively and 9 cases were positive for p53 and bcl-2 protein. In other words, the positive cases for EB virus in combination with the expression of p53 and bcl-2 were 50%, whereas 70% were positive for both p53 and bcl-2.

CONCLUSIONS

The positive rates of EB virus in our series are different from some reports of African-Burkitt's and similar to many other reports of endemic Burkitt's lymphoma. The expression of p53 and bcl-2 proteins are significantly correlated with stage; high in stages III-IV and low in stages I-II. EB virus, p53 and bcl-2 proteins may affect each other.

Major biological effects of neurotrophic factors on retinal ganglion cells in mammals

The mammalian visual system, particularly retinal ganglion cells, has been used for studying the functions of neurotrophic factors on neurons for many years. The major biological effects of neurotrophic factors on retinal ganglion cells observed so far are the promotion of viability and axonal regeneration. However, there are still some controversies regarding the effects of neurotrophic factors on retinal ganglion cells in the literature. This review is aimed to summarize the available information on the biological actions of these neurotrophic factors on survival and axonal regeneration of retinal ganglion cells and the expressions of neurotrophic factor receptors in the retina. Generally, brain-derived neurotrophic factor, neurotrophin-4/5, fibroblast growth factor and glial cell line-derived neurotrophic factor increase the survival of retinal ganglion cells while the effect of ciliary neurotrophic factor on the viability of adult retinal ganglion cells is controversial. The ciliary neurotrophic factor is the only effective factor in promoting long distance axonal regeneration of retinal ganglion cells whereas brain-derived neurotrophic factor and neurotrophin-4/5 only enhance neurite sprouting within the retina.

[5 cases report of Kaposi's sarcoma]

OBJECTIVE

To aid clinical diagnosis and management of Kaposi's sarcoma.

METHODS

3 male and 2 female of classical Kaposi's sarcoma were analysed by clinical and pathological examinations.

RESULTS

All the patients presented hemorrhagic or flue plagues nodules that could be fused together or ulceration. The lesions could reappear and get relived by themselves, The retroperitoneal lymphnodes was involved in one case, together with hypoxemia, oral ulceration, conjunctivitis and keratitis. The tumor behaved intensive spindle-cell sarcoma with obvious karyokinesis.

CONCLUSION

The affected organ in classical kaposi's sarcoma were mainly skin, rarely internal organs. The diagnosis were verified on pathology and the treatment could rely on radiotherapy, chemotherapy and local resection.

The effects of central administration of neurotrophins or transplants of fetal tectal tissue on retinal ganglion cell survival following removal of the superior colliculus in neonatal rats

In neonatal rats, intraocular injections of brain-derived neurotrophic factor (BDNF) or neurotrophin 4/5 (NT-4/5) enhance the survival of retinal ganglion cells (RGCs) following superior colliculus (SC) ablation [Q. Cui, A.R. Harvey, At least two mechanisms are involved in the death of retinal ganglion cells following target ablation in neonatal rats, J. Neurosci., 15, 1995, pp. 8143-8155.]. The aim of the present study was to determine if: (i) fetal tectal tissue grafted into the lesion site, or (ii) neurotrophins applied centrally to the injured SC, also decreased lesion-induced RGC death. Nuclei of tectally projecting RGCs were identified by injecting diamidino yellow (DY) into the left SC of 2-day-old (P2) Wistar rats. Injected SCs were lesioned at P4. In some animals, embryonic (E16) tectal tissue was then implanted into the lesion cavity; host rats were perfused 24 h or 20 days later. In short-term (24-h) studies, the number of DY-labelled pyknotic profiles was compared to the number of normal DY-labelled RGCs in retinal wholemounts (right eyes). The proportion of dying RGCs in animals with grafts (10.7%, n = 17) was not significantly different from lesion-only rats (13.2%, n = 26). Nonetheless, the long-term (20-day) study showed that, in most rats, fetal tectal tissue survived in the lesion cavity and in some cases, the grafts received host retinal input. In another group, different doses of BDNF or NT-4/5 were applied to the SC after P4 tectal lesions. Rats were perfused 24 h later and the number of pyknotic vs. normal DY-labelled RGCs was determined. Initial trials in which SC lesions were filled with gelfoam soaked in BDNF or NT-4/5 were unsuccessful; however, RGC death was reduced (p < 0.05, Dunnett's test) in rats that received gelfoam implants as well as focal neurotrophin injections into SC rostral to the lesion. The lowest pyknotic rate in individual animals from the BDNF and NT-4/5 groups was 2.41% and 2.01%, respectively. Overall, the proportion of dying RGCs was 7.0% (n = 8) for BDNF and 7.4% (n = 17) for NT-4/5 treated rats. Normal RGC densities were also significantly higher in these animals. NT-4/5 topically applied to the posterior surface of the eye did not reduce RGC death. The data show that the viability of injured neonatal RGCs is increased by specific retrograde neurotrophin-mediated survival signals which can be activated from the SC.

Preventive effect of artemether on schistosome infection

OBJECTIVE

To study the preventive effect of artemether (Art) in protecting the people from schistosome infection during flood fighting in schistosomiasis endemic area of Poyang Lake, Jiangxi Province.

METHODS

From mid July to mid August in 1996, the water level in Poyang Lake rose due to torrential rains and 2 embankments, Zhedi and Jiangtongdi, which appeared in dangerous situation and were selected as the pilot spots. After those who went to fight against flood arrived at the pilots their sera were collected within 48 hours and were examined with indirect hemagglutination test (IHA), enzyme-linked immunosorbent assay (ELISA) and McAb-ELISA. Individuals with negative outcome in the 3 tests were then selected as the study subjects and were allocated randomly to the Art or the control group. The first dose of Art given to the individuals contacted with the infested water within 11-15 days was 6 mg/kg. If the individual continually contacted the infested water, the same dose of Art was given once every 15 days. After the individuals withdrew from the pilot, one more dose of Art was administered 7-15 days later. Placebo (starch) was given to individuals in the control group at the same period as in artemether group. Stool examinations were made in both groups 40-50 days after the last medication for evaluation of the preventive effect of artemether. Double blind method was used in the administration of both artemether and placebo.

RESULTS

In Zhedi pilot, the individuals fought against flood for about 1 month. In Art group, 99 individuals receiving 3 doses of the drug completed the stool examination with egg-positive rate of 4% and no acute schistosomiasis was seen. In the control group, among 110 people who completed the observation, 44 were egg-positive with an infection rate of 40%, and 29 were identified as having acute schistosomiasis. In Jiangtondi, the studied individuals contacted the infested water for only about 4 hours. But in the control group 4 out of 102 individuals were egg-positive, while none of the 103 individuals in Art group receiving 2 doses of the drug showed schistosome infection. No apparent side effect was seen in the people treated with artemether.

CONCLUSION

After oral Art was given to the people fighting against flood in schistosomiasis endemic area of Poyang Lake, it was shown that the oral Art has a promising effect on controlling acute schistosomiasis and reducing the infection rate.

[Further clinical analysis on the prognosis of chronic lymphocytic thyroiditis]

OBJECTIVE AND METHODS

There have been many reports on the incidence of hypothyroidism and thyroid carcinoma in chronic lymphocytic thyroiditis patients, however, the incidence of thyroid carcinoma had been a widely debated issue. Therefore 300 cases of chronic lymphocytic thyroiditis from 1964 to 1995 were reviewed. There were 37 males and 263 females, and 52 had a pathological diagnosis of chronic lymphocytic thyroiditis.

RESULTS

Among 300 patients, 2 had coexistent thyroid papillary carcinoma. The original symptom in 64.3% patients was hypothyroidism, and the total incidence of hypothyroidism was 76%. It was also indicated in this study that the occurrence of hypothyroidism in chronic lymphocytic thyroiditis patient was associated with the elevated level of antithyroglobulin antibody, enlargement and tenderness of thyroid gland.

CONCLUSION

In our study, as the low incidence of coexisted thyroid carcinoma, with the high incidence of hypothyroidism it seemed to be that the elevated antithyroglobulin antibody could be a more effective factor in the development of hypothyroidism in chronic lymphocytic thyroiditis.

Steroid-induced adipogenesis in a pluripotential cell line from bone marrow

We studied the effect of steroids on the differentiation of a pluripotential mesenchymal cell with use of a cell line (D1) from mouse bone-marrow stroma. The cells were treated with increasing (10[-9], 10(-8), and 10(-7)-molar) concentrations of dexamethasone for increasing durations ranging from forty-eight hours to twenty-one days. The appearance of triglyceride vesicles in the cells indicated that this treatment had induced the differentiation of the cell into adipocytes. The number of cells that contained the triglyceride vesicles and the expression of a fat-cell-specific gene, 422(aP2), increased with longer durations of exposure to dexamethasone and with higher concentrations of the steroid. Treatment with dexamethasone also diminished the expression of alpha1 type-I collagen mRNA and osteocalcin mRNA. The data indicate that dexamethasone stimulates the differentiation of cells in bone-marrow stroma into adipocytes as well as the accumulation of fat in the marrow at the expense of expression of type-I collagen and osteocalcin mRNA, thereby suppressing differentiation into osteoblasts.

CLINICAL RELEVANCE

Steroid-induced adipogenesis by bone progenitor cells in marrow may influence the development of osteonecrosis. It is therefore important to consider the investigation of a treatment, such as the inhibition of the metabolism and accumulation of fat in marrow, that can prevent the onset of osteonecrosis.

Pulmonary leiomyosarcoma--report of three cases

Three cases of pulmonary leiomyosarcoma were presented. The characteristic clinical features were described with review of literature. In comparison with bronchogenic carcinoma, the leiomyosarcoma has some characteristics: 1) On chest X-ray, it usually appears as a sharply demarcated, even density round mass, growing rapidly within the lung, it rarely accompanies with hilar or mediastinal lymph node metastasis. 2) The preoperative cytological or pathological diagnosis is difficult either by sputum smear or by bronchoscopic biopsy or by fine needle percutaneous aspiration biopsy. 3) Pathological differential diagnosis of leiomyosarcoma of lung from anaplastic lung cancer is difficult. In conclusion, the primary pulmonary leiomyosarcoma is a rare malignant tumor, detecting the present illness seriously, paying attention to the chest X-ray films characterize, early surgical resection is the only way to get diagnosis and effective treatment method.

[The role of amylase in abdominal fluid in evaluating severity of acute pancreatitis and its prognosis]

Acute pancreatitis (AP) was induced on 22 cats, by injecting the mixture of bile and trypsin at different doses into the main pancreatic duct (MPD). In Group A, 7 cats revealed pancreatic interstitial edema after the injection of the mixture at 0.8 mg/kg. In Group B, 8 cats received the injection of the MPD at 1.0 mg/kg which resulted in significant extensive necrosis of the pancreas. The same pathological change was found in Group C (7 cats), combined with lesions of the lung and the liver. The survival time was different, more than 7 days in Group A, 50.4 hours in Group B and 10.4 hours in Group C (P < 0.001). Amylase concentration also showed marked difference in different groups, 4,890 U/L in Group A; 13 952 U/L in Group B and 23,810 U/L (P < 0.001) in Group C. These results are directly proportional to the severity of AP, but inversely proportional to the survival time. It suggests that amylase concentration in abdominal fluid can be used as an important marker to evaluate the severity of AP and its prognosis.

[Construction of a retroviral vector expressing antisense N-myc gene]

In their previous studies the authors demonstrated that nerve growth factor-induced differentiation of neuroblastoma cell lines was closely related with nerve growth factor receptors and amplification of N-myc oncogenes. The authors have also successfully restored the nerve growth factor receptor expression in the cell lines which lacked expression of nerve growth factor receptors. In order to clearify the role of N-myc oncogenes during nerve growth factor-induced differentiation of neuroblastoma cell lines, a new retroviral vector was constructed to express antisense N-myc genes. This new vector contained a puromycin resistant gene, which allowed the authors to express another gene in the cell lines which had already been neomycin resistant.

[Detection of c-Ki-ras oncogene codon 12 point mutations in lung carcinoma, gastric carcinoma and hepatic carcinoma]

DNA extracted from paraffin-embedded tissues of 30 lung carcinomas, 40 gastric carcinomas and 22 hepatocellular carcinomas was tested for the presence of c-Ki-ras codon 12 point mutation by PCR-RFLP technique. The results showed that 20% (6/30) lung carcinomas and 2.5% (1/40) gastric carcinomas had Ki-ras codon 12 point mutation, but non of the 22 hepatocellular carcinomas displayed this point mutation. Among 6 cases of lung carcinomas of mutation, 4 were squamous carcinomas and 2 were adenocarcinomas.

[Inducing effect of dimethy-4, 4'-dimethoxy-5, 6,5',6-dimethylenedioxybipheny-2, 2'-dicarboxylate (DDB) on differentiation of leukemia HL-60 cells]

OBJECTIVE

To study the effects of anti-hepatitis drug, DDB, on leukemia cell line HL-60.

METHOD

Cytobiological methods were used.

RESULT

DDB was inhibited the proliferation of HL-60 cells. About 50% of HL-60 cells treated with DDB (10(-4)mol/L) for 6 days exhibited NBT reduction, and phagocytosis activity was also enhanced by DDB (10(-4)mol/L) for 4 days. The HL-60 cells treated with DDB turned out to be mature granulocytes morphologically.

CONCLUSION

The activity of acid phosphatase in DDB-treated HL-60 cells was significantly increased. DDB can induce HL-60 cells to differentiate along granulocyte lineage.

At least two mechanisms are involved in the death of retinal ganglion cells following target ablation in neonatal rats

Removal of the superior colliculus (SC) in neonatal Wistar rats results in a rapid loss of retinal ganglion cells (RGCs). There is an early twofold increase in RGC death 4-8 hr postlesion (PL) followed by a later 10-11-fold increase in pyknosis about 24 hr PL. We have now used neurotrophic factors (BDNF, NT-4/5, NT-3, NGF, LIF), glutamate receptor antagonists (MK-801, DNQX, CNQX), an antioxidant (N-ace-tyl-L-cysteine), and an NOS inhibitor (L-NAME) to determine whether the early and late phases of lesion-induced RGC death involved similar or different mechanisms. Normal and pyknotic nuclei of tectally projecting RGCs were visualized by injecting the left s.c. of 2 d old rats with diamidino yellow (DY). Two days later the injection site was removed. In most rats, right eyes were injected with factors immediately after the s.c. ablation. Rats were perfused either 6 or 24 hr PL. In the latter group a second intravitreal injection of the appropriate factor was sometimes made 12 hr PL. NT- 4/5 and BDNF significantly decreased RGC pyknosis 6 and 24 hr PL, whereas NT-3 was only protective 6 hr PL. LIF slightly reduced RGC death 24 hr PL, but NGF had no influence on RGC survival at either time point. NT-4/5 also reduced the rate of naturally occurring RGC death. MK-801, DNQX, CNQX, N-acetylcysteine, and L-NAME all prevented the early lesion-induced increase in RGC death but had no significant effect on RGC death measured 24 hr PL; none of these factors significantly reduced the rate of naturally occuring RGC death. Cycloheximide, shown previously to reduce RGC pyknosis 24 hr PL, did not prevent RGC death 6 hr PL. The data indicate that there are at least two mechanisms involved in RGC death after neonatal target ablation. The early increase is related to excitotoxic effects mediated by glutamate receptors and involves NOS and the production of free radicals. We found no evidence that RGC death measured 24 hr PL is dependent on these processes, but the later death does require protein synthesis and, most likely, the activation of an endogenous suicide program. NT-4/5 and BDNF protected RGCs from both types of lesion-induced death.

[Gene expression of growth factors, growth factor receptor and oncogenes in human lung cancer cell lines]

Gene expression of growth factors including epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), epidermal growth factor receptor (EGFR), oncogenes such as c-myc, N-ras, c-erbB2 and tumor suppressor gene P53 were studied in 4 human lung cancer cell lines using Northern blot technique. Among these cell lines were 2 adenocarcinoma cell lines, one large cell carcinoma cell line and one small cell carcinoma cell line. Expression of EGF and TGF alpha mRNAs were found in all 4 cell lines and EFGR mRNA was seen in 3 out of 4 cell lines. Among these cell lines, 2 cell lines with weaker expression of EGF and TGF alpha, expressed c-myc mRNA. Another 2 cell lines had no c-myc but expressed large amounts of EGF and TGF alpha mRNA. No expression of N-ras, c-erbB2 and p53 were found in these cell lines. The results indicate the presence of autocrine loop of growth factors in these cancer cells. The autostimulation of growth factors may be the main cause for the uncontrolled growth of cancer cells. After treating the cancer cells with EGF, anti-EGF and anti-EGFR antibodies, EGF was found to exert a mild stimulating effect on the growth of one cell line, but no effect on the other cell lines. Anti-EGF and anti-EGFR antibodies inhibited the cell growth on all cell lines. These results provided further evidence for the presence of autocrine loop of growth factors in these lung cancer cell lines.

NT-4/5 reduces naturally occurring retinal ganglion cell death in neonatal rats

The retrograde nucleophilic tracer diamidino yellow (DY) was injected into the left superior colliculi of 2-day-old rats. Two days later, right eyes were injected with either neurotrophin NT-4/5, cycloheximide (CHX), MK-801 and DNQX (glutamate receptor antagonists), or saline. Almost all rats were perfused 6-7 h later and the numbers of normal and pyknotic DY-labelled retinal ganglion cells (RGCs) were determined from retinal whole mounts. In controls (no eye injection) the proportion of pyknotic RGCs was 1.04%. This level of naturally occurring death was significantly reduced after injection of NT-4/5 (0.34%); normal RGC density was also higher in this group. RGC pyknosis was increased after saline (1.21%), MK-801/DNQX (1.22%) or CHX (1.48%) injections but only in the latter case was the increase significantly greater than control.