[Clinical application prospect of digital subtraction technique for periapical radiographs]

The composition and functions of digital subtraction system for conventional radiographs were introduced. Based on the experimental test for this system, it has been found that digital subtraction system for conventional radiographs is very valuable for the diagnoses of minute bone lesions in the bifurcation, root side and apical part of the teeth as well as in the alveolar crest. In addition, the reproducibility of the projection geometry, the principle of digital subtraction and its clinical application prospect are also discussed in the present paper.

Modulation of retinoblastoma and retinoblastoma-related proteins in regenerating rat liver and primary hepatocytes

Protein expression of the retinoblastoma (Rb) tumor suppressor gene product was examined by immunoblot analysis of nuclei isolated from regenerating rat liver after 70% partial hepatectomy (PH). Levels were almost undetectable in quiescent 0-h livers but increased 15- to 60-fold 3 to 24 h post-PH, 105-fold at 30 h, and 20- to 50-fold at 60 to 72 h post-PH. Expression returned to near baseline levels at 18, 42, and 48 h post-PH. A similar pattern of Rb protein expression in the regenerating liver was observed by indirect immunofluorescence microscopy, with peak nuclear expression at 30 h post-PH. Rb-related proteins with apparent molecular masses of 300, 156, and 74 kDa were detected in regenerating liver using mAbs to the Rb protein. Their expression increased 6- to 8-fold during regeneration, and only p156 returned to baseline levels at 60 h post-PH. Rb and its related proteins were detected in cultured primary hepatocytes, and although total protein levels did not change appreciably, there was a dramatic shift from cytosol into nuclei through 96 h. The half-life of the Rb protein was determined to be 1.9 h in regenerating liver and 2.2 h in cultured primary hepatocytes. Rb protein abundance in synchronized HuH-7 human hepatoma cells was cell cycle dependent and exhibited peak nuclear expression during S phase. Rb protein was detected primarily in its hyperphosphorylated state during liver regeneration and through the cell cycle of the HuH-7 cells. In vivo administration of transforming growth factor beta 1, an inhibitor of DNA synthesis in regenerating liver, resulted in reduced expression of Rb as well as its protein partners, cell cycle-dependent kinase 4 and cyclin E. The results suggest that in the regenerating rat liver and in synchronized HuH-7 cells, expression of Rb protein is modulated in a cell cycle-dependent fashion, remains primarily in a hyperphosphorylated state, and exhibits a relatively short half-life. The inhibition of Rb protein expression by transforming growth factor beta 1 may be linked to its simultaneous suppression of cell cycle-dependent kinase 4 and cyclin E protein levels.

Expression of human interleukin-11 cDNA in E. coli

A 551-bp hIL-11 gene fragment that includes no nucleotide sequences encoding signal polypeptide and the initial 8 amino acids of the mature protein was cloned into a high-level expression vector pEx31B of E. coli. The authors identified the recombinant plasmid, designated pEx31-IL11, by restriction endonucleases digestion and DNA sequencing. The resulting recombinant plasmids were then used to transform E. coli strain HB101, and expression in the PL promoter system, which is temperature-regulated, was achieved. The expressed fusion protein amounts to 50% of total bacterial proteins. The hIL-11 protein expressed in E. coli was fused to the N-terminal 99 amino acids of the MS2 polymerase to form the inclusion body. These recombinant proteins can be purified to about 80% by extracting inclusion body with urea. One IL-6-dependent cell line 7 TD1 was used for bioassay. The recombinant hIL-11 protein was preliminarily purified and renatured to a specific activity of 10(5)U/mg, even in the presence of an excess of a neutralizing anti-IL-6 antibody.

Purification of developmentally regulated avian 400-kDa intermediate filament associated protein. Molecular interactions with intermediate filament proteins and other cytoskeleton components

IFAPa-400, a 400-kDa developmentally regulated protein thought to be associated with intermediate filaments, has been purified from chick embryo hearts to investigate its interaction with vimentin and other IF proteins and to identify other cellular components to which this cytoskeletal protein associates. Previous studies suggested that this protein was associated with the vimentin-containing intermediate filament lattice of myoblasts and neuroblasts before their terminal differentiation, providing these cells with a particular intermediate filament cytoskeleton that could satisfy specific mechanical requirements during their intense morphogenetic activities. Although IFAPa-400 partially reassociated with vimentin and desmin in disassembly-reassembly experiments using crude IF preparations from chick embryo hearts, in vitro recombination of purified IFAPa-400 with vimentin and desmin failed to demonstrate any direct association. When purified IFAPa-400 was used as a probe in blot overlay assays, however, specific binding to vimentin and desmin was observed, providing the first evidence of a physical association between IFAPa-400 and intermediate filament proteins. The blot overlay experiments also demonstrated that IFAPa-400 binds to two unidentified polypeptides of 19 and 32 kDa. These results are thus consistent with the hypothesis that a structural lattice requiring a vimentin-IFAPa-400 combination constitutes the intermediate filament system of myogenic and neurogenic cells.

[Effects of occlusal trauma on temporomandibular joints in rabbits: a scanning electron microscopic study]

Six rabbits with unilateral occlusal splints on the mandibular left molars for one month, three months or five months were examined to study the ultrastructure of the surface of the temporomandibular joint. Four rabbits were used as control. The results showed that the surface layer of the disk and articular cartilage were damaged. Severe fibrillation with sheets of fibers, collagen fibrils and collagen bundles inside fissures and craters were observed. These changes were seen in all rabbits with occlusal trauma and also in control rabbits for five months. The findings suggested that occlusal trauma could result in degenerative changes of the temporomandibular joint.

[Interleukin-6 activity in synovial fluids of temporomandibular joint distrubance syndrome]

Using the IL-6-dependent mouse hybridoma cell line KD 83, IL-6 biological activity in synovial fluids of the patients with Temporomandibular Joint Disturbance Syndrome (TMJDS) was tested. The results show that IL-6 level is high in 13 cases of 18 patients with TMJ degenerative changes and 5 cases of 12 patients with TMJ Disc Displacement. IL-6 level is less than 100 U/ml in all patients with Masticatory Muscle Disorder (59.4 +/- 29.4 U/ml). In addition, it has been found that TMJDS tends to have acute and chronic stages and IL-6 is probably related to acute stage of the patients.

Comparison of acute hepatocellular proliferating cell nuclear antigen labeling indices and growth fractions, p34cdc2 kinases, and serum enzymes in carbon tetrachloride-treated rats

We evaluated various biomarkers associated with cell proliferation immediately following insult with the classic hepatotoxicant carbon tetrachloride (CCl4). Rats were administered a single necrogenic dose of CCl4 and euthanized at either t = 4, 8, 12, 16, or 24 hr postdose. Parameters evaluated included the following: immunohistochemical detection of hepatocellular proliferating cell nuclear antigen labeling indices (PCNA-LIs; percentage of cells in S phase) and growth fractions (PCNA-GFs; percentage of cells in the cell cycle); PCNA and the cyclin-dependent kinase p34cdc2 (CDK) protein in S-9 fractions by Western blot and enzyme-linked immunosorbent assay (ELISA); and liver-related serum enzymes. An increase in PCNA-GF was observed at t = 4 hr, concomitant with elevations in CDK and PCNA protein (Western blot). PCNA-LIs were increased by t = 24 hr, as were CDK and PCNA by ELISA. Sorbitol dehydrogenase was the most sensitive enzyme, with increases observed at t = 4 hr. Our results indicate that PCNA-GF, CDK, and PCNA levels reflect hepatocellular regeneration as early as 4 hr following CCl4 insult. We conclude that these assays are early and sensitive indicators of acute hepatotoxicity that may be advantageous to evaluate in the early stages of exploratory studies.

[Evaluation of the condylar position in the diagnosis of temporomandibular joint dysfunction syndrome]

26 cases with Temporomandibular Joint Dysfunction Syndrome (TMJDS) were included in the present study. Fully corrected lateral tomogrames of TMJ in the intercuspid position were taken for all the cases; and fully corrected lateral arthrotomogrames were taken for 19 cases (21 joints) of them. The area and linear measurements of the joint space were made with the aid of computer. The results showed that the position of the condyle in the patients with TMJDS was located in the posterior position of the fossa. Statistics results showed that there was significant difference between the patient group and control group. Although the posterior displacement of the condyle was often associated with the anterior displacement of the disc, it was not always agreement with the anterior disc displacement. So, the exact diagnosis of disc displacement should be still on the basis of arthrography or other examinations, such as CT or MRI.

Overexpression of human apolipoprotein A-I in transgenic rats and the hyperlipoproteinemia associated with experimental nephrosis

Hyperlipoproteinemia contributes both to kidney disease progression and the development of atherosclerosis. Elevated high density lipoprotein cholesterol and apolipoprotein A-I (apoA-I) serum levels are independent factors protective against the atherosclerotic process. We examined the effects in a transgenic rat model of human apoA-I expression on the hyperlipoproteinemia and edema after puromycin aminonucleoside-induced nephrosis in three groups of animals: low line (TgR[hAI]low, human plasma apoA-I = 16.0 mg/dl); high line (TgR[hAI]high, 284 mg/dl); and non-transgenic litter mates (TgR[hAI]non). Nephrosis increased total plasma apoA-I levels 2-fold in TgR[hAI]non rats (75 vs. 162 mg/dl) and 4-fold in the TgR[hAI]low (97 vs. 458 mg/dl) and TgR[hAI]high rats (356 vs. 1,346 mg/dl). In both transgenic lines, this increase was due mainly to elevations of serum human apoA-I. The hepatic steady-state levels of rat apoA-I mRNA increased 5- to 7-fold in all three groups, while human apoA-I mRNA levels increased 21- and 65-fold in the low and high expressing groups, respectively, indicating a different degree of responsiveness of the rat and human genes. While nephrotic TgR[hAI]non and TgR[hAI]low rats showed severe hyperlipoproteinemia and edema, much lower levels of edema and of serum triglycerides, phospholipids, and cholesterol were seen in the TgR[hAI]high group. Urinary excretion of apoA-I, phospholipids, and cholesterol was significantly increased in the TgR[hAI]high group, indicating this as one possible mechanism for the relatively lower serum levels of these lipids. We conclude that the human apoA-I gene is responsive to nephrosis and that human apoA-I-transgenic rats with this syndrome provide an animal model for the study of human high density lipoprotein and apoA-I metabolism.

[Histopathologic classification of 1921 orbital tumors]

PURPOSE

The retrospective study is undertaken to determine the histopathologic types of space-occupying lesions of the orbit in 1921 cases examined between 1953-1992 at the Eye Pathology Laboratory of Shanghai Medical University.

METHODS

The authors reviewed old diagnostic pathologic slides on file including HE stain as well as special stains, if available, for all the indeterminate cases. Newly prepared immunohistochemical stains are made for the controversial cases to help diagnosis. Some slides are discussed and diagnosed by Pathology Slide Meeting of the Shanghai Surgical Pathology Society. Cases with diagnosis not agreed upon by the pathology meeting are excluded from this study.

RESULTS

The 5 leading malignant orbital tumors are malignant lacrimal gland tumors (138 cases, 32%), malignant lacrimal sac tumors (112 cases, 26%), rhabdomyosarcomas (65 cases, 15%), lymphosarcomas (56 cases, 13%), and malignant hemangiopericytomas (31 cases, 7%). The 5 leading benign orbital tumors are cavernous hemangionas (411 cases, 36%), dermoid cysts (152 cases, 13%), benign mixed tumors (150 cases, 13%), inflammatory pseudotumosr (129 cases, 11%), and schwannomas (92 cases, 8%). Rare tumors of the orbit include alveolar soft tissue sarcoma, chondrosarcoma, mesenchymal chondrosarcoma, synovial sarcoma, giant cell tumor, granular myoblastoma, yolk sac tumor, and retinal anlage tumor.

CONCLUSION

This study, in agreement with other reports of the statics study of the orbital tumors demonstrates the prevalence of hemangiomas, lacrimal gland tumors and lymphoid pseudo-tumors to be the common space-occupying lesions in the orbit. Some rare tumors are discussed.

Tumor necrosis factor in synovial fluid of patients with temporomandibular disorders

PURPOSE

To assess tumor necrosis factor (TNF) activity in synovial fluid from patients with temporomandibular disorders.

PATIENTS AND METHODS

Tumor necrosis factor (TNF) activity in synovial fluid from 27 patients with temporomandibular disorders (TMDs) was studied using the MTT tetrazolium WEHI 164 clone 13 cell cytotoxicity assay.

RESULTS

No detectable TNF levels were found in five patients with a masticatory muscle disorder, but elevated TNF levels were found in 5 of 11 patients with TMJ disc displacement, and in 9 of 11 patients with degenerative joint disease.

CONCLUSION

The findings of biologically active TNF in the synovial fluid of these patients suggests that it may play a role in the pathogenesis of certain temporomandibular disorders.

[Investigation on scoliosis incidence among 24,130 school children]

Through the screening on scoliosis among 24,130 school children in Hu Guan County, Shanxi Province, it showed that the forward-bending test was positive in 1,794 children (7.4 per cent), with male 3.64 per cent and female 3.8 per cent. The hump inclination angles that were more than 4 degrees were found in 665 children (2.75 per cent). The Cobb angles that were more than 10 degrees were found in 347 children. The incidence rate was 1.44 per cent, with a male to female ratio of 1:1.17. Most of them were idiopathic scoliosis.

PDI-, PPI- and chaperone-catalyzed refolding of recombinant human IL-2 and GM-CSF

The studies on PDI-, PPI- and chaperone-catalyzed refolding of recombinant human IL-2 and GM-CSF show that PDI can prevent the mismatch of disulfide bonds and formation of aggregates by interchains linkage; furthermore, PDI can correct the mismatching of disulfide bonds in IL-2 isomers. PPI can increase the rate of folding reaction while chaperone can prevent the aggregation during the folding process. In addition, there is a synergistic effect between them.

[Gallbladder contraction and microscopi observation of the gallbladder wall in gallstone patients]

On the basis of oral cholecystography (OCG), we selected gallstone patients for nontoperative intervention. Their gallbladder function was considered as normal when gallbladder contracted over 50%-75% after a fat meal at 1 hour. We collected 99 gallstone patients and 19 normal controls; gallbladder function was normal in 77 patients and poor in 22. After a fat meal gallbladder volumes were calculated by B ultrasonography. The results showed that both fasting and residual volume in patients with so-called normal contraction were significantly greater than that in the controls (P < 0.001), though the contraction rate was not different. The combination of gallbladder contraction rate measurement and residual volume calculation by ultrasonography was superior over traditional OCG.

[Evaluation of radiographic diagnosis on osteoarthrosis of the temporomandibular joint]

84 cadavers' temporomandibular joints were used to compare the results shown in standard lateral tomographs and Schuller's position films with gross views on the bone and cartilage changes. The results and conclusions were as follows: (1) The positive rates of the radiographic evidences were associated with the degrees of the macroscopic lesions. The more severe the macroscopic lesion, the higher the positive rate of radiographic evidence. (2) The sensitivity of radiographic examination was positively correlated with the extent of the macroscopic lesion. So, the negative predictive value was. However, the specificity and the positive predictive value of the radiographic examination were negatively correlated with macroscopic change index. It has been found that the more the extent of osteoarthrosis changes, the higher the sensitivity of radiographic examination; the higher the negative predictive values, the higher the positive rate of radiographic evidence, and the lower the underdiagnosis rate was. Meanwhile, the more the extent of bone pathological changes in the joint, the lower specificity of the radiographic examination, and the lower the positive predictive values and the misdiagnosis is increased. (3) The radiographic diagnostic value based on the standard latreal tomographs of TMJ, Schuller's position films or based on the both methods was not satisfied. Its underdiagnosis rate was higher. Therefore, we suggest that multiple-layers lateral tomography should be widely used in clinical practice.

Stimulatory and inhibitory effects of interleukin (IL)-4 and IL-13 on the production of cytokines by human peripheral blood mononuclear cells: priming for IL-12 and tumor necrosis factor alpha production

The production of cytokines in monocytes/macrophages is regulated by several different cytokines that have activating or inhibitory effects. Interleukin (IL)-10, IL-4, IL-13, and transforming growth factor (TGF)-beta are usually considered to be the most important macrophage-deactivating factors, with inhibitory effects on cytokine production. Unlike IL-10 and TGF-beta, which appear to act as downmodulators of many phagocytic cell functions, the mode of action of IL-4 and IL-13 is more complex. Addition of IL-4 and IL-13 to peripheral blood mononuclear cell (PBMC) cultures inhibited production of IL-12, tumor necrosis factor (TNF)-alpha, IL-10, and IL-1 beta induced by lipopolysaccharide (LPS) or Staphylococcus aureus added simultaneously with the cytokines. However, pretreatment of PBMC with IL-4 or IL-13 for > or = 20 h enhanced the production of IL-12 and TNF-alpha in response to LPS or S. aureus several fold in these cells; this IL-4-induced priming for the two cytokines was inhibited by anti-IL-4 neutralizing antibodies. IL-4 priming also enhanced the accumulation of IL-12 and TNF-alpha mRNA induced by LPS and S. aureus. The enhanced accumulation of transcripts for the IL-12 p35 and p40 chains by IL-4 priming was reflected in enhanced secretion of both the IL-12 free p40 chain and the p70 heterodimer. These results suggest an unexpected complexity in the regulatory role of IL-4 and IL-13 in immune responses.

Interleukin-12 production by human polymorphonuclear leukocytes

Human polymorphonuclear leukocytes (PMN) stimulated by lipopolysaccharide (LPS) produce interleukin-12 (IL-12). Both the free IL-12 p40 chain and minute amounts of the biologically active IL-12 p70 heterodimers are produced by PMN. Interferon-gamma (IFN-gamma) enhanced the LPS-induced secretion of both the free IL-12 p40 chain and the p70 heterodimer by approximately fivefold. As observed for other IL-12-producing cell types, the ratio of free p40 chain to p70 heterodimer secreted by LPS-stimulated PMN was approximately 20:1. LPS induced a 100-fold increase of IL-12 p40 mRNA, but had minimal effect on p35 mRNA accumulation. IFN-gamma enhanced the LPS-induced accumulation of p40 mRNA and directly induced a several-fold increase in the accumulation of p35 mRNA. Therefore, the combined effect of LPS and IFN-gamma induced sufficient expression of both p40 and p35 to attain production of the biologically active p70 heterodimer at physiologically relevant concentrations. The ratio between p40 and p35 mRNA abundance in PMN stimulated with both LPS and IFN-gamma was approximately 200:1, explaining the secretion of the free p40 chain in much higher concentrations than the p70 heterodimer. IL-10, an inhibitor of the production of various cytokines in PMN, also suppressed IL-12 mRNA accumulation and secretion by PMN. Because of the important immunoregulatory function of IL-12, in particular induction of IFN-gamma production and facilitation of T helper cell type 1 response, the ability of PMN to produce IL-12 suggests that neutrophils may play an active role in the regulatory interaction between innate resistance and adaptive immunity.

Magnetic resonance imaging verification of a multi-compartment perfusion model for a chromatography gel phantom

A model of MRI signal intensity was developed for chromatography column phantoms containing Sephadex gels, which were used to simulate tissue perfusion and the exchange of protons between extravascular and intravascular tissue compartments. Computer simulations of two-compartment and three-compartment models were compared in experiments that used two chromatography columns. One column contained a Sephadex G-25 gel that had a smaller pore size and a slower rate of exchange between extrabead and intrabead compartments than did a second column, which contained a G-50 gel with a larger pore size. In both columns the beads were of approximately the same size to simulate the same ratio of intrabead volume to extrabead volume. Slice-selective spin-echo experiments were performed with the columns oriented parallel to each other in a 1.5 T imager and parallel to the magnetic field, with water flowing through each column perpendicular to the slice at mean flow velocities ranging between 0 and 0.66 mm/s. The results of the experiments agreed with computer simulations, which showed that the MRI signal intensity in the perfused columns is a function of the rate of exchange between extrabead and intrabead compartments. The exchange process modifies the transit time of protons passing through an excited region. The simulations also showed that both two-compartment and three-compartment models could be used to fit the experimental data. Experiments with chromatography gel columns are a preliminary investigation into the potential of using MRI to measure the exchange between extravascular and intravascular compartments of endogenous protons during blood perfusion of biological tissue.

[Repair of scalp defects with skull exposure]

The methods for repairing scalp defects and skull exposure are introduced. From 1980 to 1991, 9 cases of scalp defects and skull exposure from injury or tumor extirpation were treated with free omentum transfer with split skin graft, free flap or axial flap transfer. The surgical procedure was described in detail. For the whole defect of scalp with skull exposure the authors consider the free anterior-lateral femoral flap more appropriate and suggest that the free omentum flap be avoided as far as possible.

Cytotoxic clerodane diterpenes from Polyalthia barnesii

Three cytotoxic clerodane diterpenes were purified from an ethyl acetate-soluble extract of the stem bark of Polyalthia barnesii, namely, 16 alpha-hydroxycleroda-3,13(14)Z-dien-15,16-olide, a known compound, and two novel compounds, 3 beta, 16 alpha-dihydroxycleroda-4(18),13(14)Z-dien-15,16-olide and 4 beta, 16 alpha-dihydroxyclerod-13(14)Z-en-15,16-olide. These compounds were found to exhibit broad cytotoxicity against a panel of human cancer cell lines.

Indole alkaloids from Peschiera laeta that enhance vinblastine-mediated cytotoxicity with multidrug-resistant cells

Coronaridine [1], conoduramine [2], and voacamine [3], three indole alkaloids isolated from Peschiera laeta, have been found to enhance the cytotoxic response mediated by vinblastine [4] with multidrug-resistant KB cells. Inhibition of vinblastine binding with membrane vesicles isolated from this cell line was also assessed, and the bisindole alkaloids conoduramine [2] and voacamine [3] were found to be more potent inhibitory agents than the monomeric alkaloid, coronaridine [1]. Thus, these compounds appear to function by binding with P-glycoprotein.