Hua xi yi ke da xue xue bao = Journal of West China University of Medical Sciences = Huaxi yike daxue xuebao最新文献

Objective: In this study, we established the optimal condition and duration for the primary culture of the human tooth pulp cell with collagenase digestion method.

Method: Pulp tissue was removed from healthy young human teeth extracted for orthodontic purposes, and then the pulp was digested by collagenase separately in duration of 30 mins, 1 hr, 2 hrs, 3 hrs. After the digestion, the viability and digestion efficiency were evaluated by microscopy and trypan-blue dying. The cytokeratin and vimentin were immunocytochemically detected to identify the cell phenotype. The tissue explant culture and trypsin digestion were set as controls.

Results: After digestion of 1 hr, 2 hrs, or 3 hrs, little tissue residue was left, while there is still much tissue remained after digestion of 30 mins. The viability decreased with the elongation of digestion duration.

Conclusion: 37 degrees C, continuing stirring and 1 hr of type I collagenase digestion are the optimal conditions for the primary culture of human tooth pulp with digestion method.

Objective: This study was designed to determine the difference in the implant to abutment joint stability resulting from the preparation procedure in adjusting the TiAdapt abutment.

Methods: Thirty Branemark implants (10RP, 10NP, 10WP) and 10 TiAdapt RP, TiAdapt NP and TiAdapt WP abutments formed the experimental populations of 3 groups. Samples in each groups were further divided into subgroups A and B. Subgroup A was operated with preparation procedure whereas the other served as control. The torque required and the gap between abutment and implant before and after preparation were measured.

Results: There were no significant differences in group RP and group WP; there were significant differences in group NP at the significance level of 0.05.

Conclusion: These results indicate that the implant to abutment joint stability has been strengthened by the abutment preparation procedure.

Objective: To acquire stable expression of envelope proteins of hepatitis C virus in insect host cells and use the expressed envelope proteins for detecting the serums of patients with hepatitis C.

Methods: The envelope gene of HCV H strain was amplified by PCR and inserted in baculovirus vector BacPAK8, and then recombined with linear BacPAK6 DNA in insect cells. The recombinant baculoviruses were selected by the plaque assay. The insect cells were infected by the recombinant baculoviruses that contained the target gene produced E1, E2 proteins, which were characterized with the immunoblot assay and the immunofluorescence and were used to determine 35 serum samples of patients with hepatitis C.

Results: The expressed E1, E2 proteins showed that the relative molecular mass of E1 is about 21 x 10(3) and 33 x 10(3), and that of E2 is about 60 x 10(3). Detection of immunofluorescence indicated that E1, E2 proteins are localized in the cytoplasm of the infected cells. Four of the 35 serums responded to expressed E1; one of them was found to recognize E2 protein. Three of 9 serums which were HCV RNA positive by PCR testing got united to E1, E2.

Conclusion: The HCV envelope protein can be expressed stably in the insect cells. Expressed E proteins could be used in the serologic analysis of the patients' serums.

Objective: To isolate and purify new antibiotic peptides from human lymphokine activated killer (LAK) cells.

Methods: Preparative Acid-Urea Polyacrylamide Gel Electrophoresis and Reverse Phase HPLC were performed to isolate and purify polypeptides from the acid extract of human LAK cells. The molecule weight was analyzed by Tricine-SDS-PAGE. Radial agar diffusion assay was used to analyze the antibacterial activities.

Results: Several antibiotic peptides were isolated. Two peptides were purified from fractions HLP-2, HLP-3, which had molecular weight of around 7.9 x 10(3) u and 4 x 10(3) u and were named HLP-2b and HLP-3a, respectively. Four peptides with molecular weight of 7.2 x 10(3) u, 10.4 x 10(3) u, 6.2 x 10(3) u and 6.2 x 10(3) u were almost purified and were named HLP-2a, HLP-2c, HLP-3b and HLP-3c, respectively. HLP-2b, HLP-2a, HLP-2c, HLP-3b and HLP-3c all had antimicrobial activities against S. Aureus and C. Albicans, and HLP-3a against S. Aureus only.

Conclusion: Human LAK cells contained a variety of antimicrobial peptides.

Objective: To investigate the prevalence rate and epidemiological features of teratomas in China.

Methods: From 1987 through 1992, hospital-based cluster sampling method was adopted for collecting data. During that period all live or still births with 28 weeks of gestation or more were assessed within 7 days after delivery.

Results: 238 teratoma cases were identified in 4,489,692 births, including 198 isolated and 40 associated forms of teratomas. The prevalence rates of total teratomas, isolated and associated forms of teratomas were 0. 53/10000, 0.44/10000, 0.09/10000 respectively. The prevalence rates in urban areas and rural areas were 0.46/10000 and 0.66/10000, respectively. The prevalence rates of teratomas in male and female births were 0.80/10000 and 0.27/10000 correspondingly. The ratio of male to female teratomas was 1:2.76. The perinatal fatality rate of teratomas was 55.0%.

Conclusion: The most frequent teratomas were isolated forms. Time trends have not been found in the occurrence of teratomas. High prevalence in urban areas has been observed, compared to that in rural areas. The prevalence of teratomas in female births is three times as high as that in male births. In view of the high fatality rate, prenatal diagnosis and perinatal management of teratomas should be strengthened.

Objective: To compare the influence of 6 trace element agents containing fluoride versus 6 trace element agents not containing fluoride on the growth of mutants of S. mutans and detect the interaction between fluoride and trace elements.

Methods: Six trace element agents containing fluoride [SnF2, ZnF2, SrF2, LaF2, (NH3)2MoF8, NaF] and 6 trace element agents not containing fluoride [SnCl2, SrCl2, LaCl2, ZnAc2, (NH3)2MoO4, NaCl] were selected. The continuous anaerobic cultivating technique and the absorbency of bacteria liquid and the count of bacteria were used to assess the effects of different agents on the growth of S. mutans.

Results: NaF, SnF2, SnCl2, ZnF2, ZnAc2, (NH3)2MoF8 and (NH3)2MoO4 were found to have strong inhibition effects on the growth of mutant of S. mutans(P < 0.01). SnF2 had more stronger inhibition effects than SnCl2; ZnF2 had more stronger inhibition effects than ZnAc2, no significant differences were seen between (NH3)2MoF8 and (NH3)2MoO4. SnF2 and ZnF2 had most potent inhibition effects(P < 0.01). No significant differences were observed between SrF2, SrCl2, LaCl2, LaF2, NaCl and the control groups(P > 0.05).

Conclusion: The agents containing fluoride and trace elements, such as stannum and zinc had the effects of prohibiting the growth of mutant of S. mutans, As far as caries prevention is concerned, the agents containing both fluoride and trace elements are more effective than mono-fluoride, the potential mechanism may be the synergistic action between fluoride and trace elements.

Objective: To assess the feasibility and adequacy of double stapling technique (DST) and anal sphincter preservation with laparoscopic approach for low rectal cancer.

Methods: DST and low/ultralow/coloanal anastomoses were performed laparoscopically on 30 patients with low rectal cancer.

Results: The 30 laparoscopic DST and low/ultralow/colo-anal anastomoses with anal sphincter preservation were successfully completed, and not one of the cases was converted to open procedures. The operation time was 155 min with the ranges from 110 to 320 min. The operative blood loss was 20 ml with a range between 5 and 80 ml. The time of bowel function restoration and post-operative ambulation was 1-2 days after the operation. 14 patients had postoperative analgesic requirement. The hospital stay varied from 5 to 14 days, averaging 8 days, and there were no intraoperative and postoperative complications in the 30 patients.

Conclusion: Laparoscopic DST and low/ultralow/colo-anal anastomoses for low rectal cancer is a perspective minimally invasive technique, which is feasible, safe and effective. With the use of this technique, surgeons could accomplish higher rates of sphincter preservation, more accurate autonomic nerve preservation and good micturation with decreased postoperative pain and rapid recovery.

Objective: Nuclear factor kappa B is very important in cis-activation which regulates the expression of many genes. This study inquired into the mechanism of cancer cell metastasis.

Methods: Immunohistochemical method was used for studying the expression of nuclear factor kappa B in cancer cells of human metastasized rectum adenocarcinoma.

Results: Expressed nuclear factor kappa Bp65 was found in the cancer cells of peritumoral tissues and metastasized lymph nodes. The reaction product was located in the cytoplasm and cytonucleus.

Conclusion: The findings of this study suggest a strong correlation between the expression of nuclear factor kappa B in cancer cells and the metastasis of cancer.

Objective: To investigate the relation of Jak3 constitutive activation and acute lymphoblastic leukemia(ALL).

Methods: NALM-6 cells were treated with varying concentrations of AG490, a Jak3 inhibitor. Apoptosis and proliferation of NALM-6 cells were tested by flow cytometry (FCM) analysis and MTT assay.

Results: With the exception of AG490 5 mumol/L, the AG490 10, 15, 20 mumol/L induced a strong apoptotic response in NALM-6 cells by FCM analysis(P < 0.05) and significantly inhibited the proliferation of NALM-6 cells by MTT assay(P < 0.05). All of the effects were dose-dependent.

Conclusion: Jak3 inhibitor AG490 can inhibit proliferation and induce apoptosis in NALM-6 cells, and Jak3 activation is associated with pre-B ALL.

Objective: To investigate the expression of insulin receptor in human hepatocellular carcinoma and it's adjacent tissue.

Methods: The human hepatocellular carcinoma and it's adjacent tissue specimens were obtained from 12 patients with histologically confirmed hepatocellular carcinoma at surgery and were immediately frozen under -80 degrees C. Insulin was radioiodinated using Ch-T method. Cell membrane fraction of human hepatocellular carcinoma and it's adjacent tissue were isolated by sucrose density gradient centrifugation. Receptor binding of 125I-insulin to human hepatocellular carcinoma and it's adjacent tissue were performed. Binding data were calculated according to Scatchard using the ligand program. Statistical comparison was made with the paired t-test.

Results: The Kd values of human hepatocellular carcinoma and it's adjacent tissue were 2.12 +/- 0.62 nmol/L and 2.21 +/- 0.78 nmol/L respectively; the values of Bmax were 1.94 +/- 0.64 pmol/mg protein and 1.42 +/- 0.57 pmol/mg protein respectively. The Bmax value of human hepatocellular carcinoma was significantly higher than that of the adjacent tissue (P < 0.05), whereas the two Kd values had little difference (P > 0.05).

Conclusion: The results of this study showed that human hepatocellular carcinoma expressed denser insulin receptors than it's adjacent tissue, but there was no significant increase in the affinity of the carcinoma to insulin.