Steam activation of chars produced from oat hulls and corn stover

Oat hulls and corn stover were used to produce chars at approximately 500 degrees C. The carbon concentrations of oat hull char and corn stover chars produced were 72.3 and 68.0 wt.%, respectively. Both activation burn-off and Brunauer-Emmett-Teller (BET) surface area appear to exhibit a linear relationship with respect to activation time of oat hulls. As to corn stover activated carbons, there is no linear relationship between activation time and BET surface area. However, activation burn-off of and activation time appear to relate in a linear manner for the activated carbons produced from corn stover chars. Oat hull is better than corn stover as a raw material for the production of activated carbon.

Radiation-induced pulmonary toxicity: a dose-volume histogram analysis in 201 patients with lung cancer

PURPOSE

To relate lung dose-volume histogram-based factors to symptomatic radiation pneumonitis (RP) in patients with lung cancer undergoing 3-dimensional (3D) radiotherapy planning.

METHODS AND MATERIALS

Between 1991 and 1999, 318 patients with lung cancer received external beam radiotherapy (RT) with 3D planning tools at Duke University Medical Center. One hundred seventeen patients were not evaluated for RP because of <6 months of follow-up, development of progressive intrathoracic disease making scoring of pulmonary symptoms difficult, or unretrievable 3D dosimetry data. Thus, 201 patients were analyzed for RP. Univariate and multivariate analyses were performed to test the association between RP and dosimetric factors (i.e., mean lung dose, volume of lung receiving >or=30 Gy, and normal tissue complication probability derived from the Lyman and Kutcher models) and clinical factors, including tobacco use, age, sex, chemotherapy exposure, tumor site, pre-RT forced expiratory volume in 1 s, weight loss, and performance status.

RESULTS

Thirty-nine patients (19%) developed RP. In the univariate analysis, all dosimetric factors (i.e., mean lung dose, volume of lung receiving >or=30 Gy, and normal tissue complication probability) were associated with RP (p range 0.006-0.003). Of the clinical factors, ongoing tobacco use at the time of referral for RT was associated with fewer cases of RP (p = 0.05). These factors were also independently associated with RP according to the multivariate analysis (p = 0.001). Models predictive for RP based on dosimetric factors only, or on a combination with the influence of tobacco use, had a concordance of 64% and 68%, respectively.

CONCLUSIONS

Dosimetric factors were the best predictors of symptomatic RP after external beam RT for lung cancer. Multivariate models that also include clinical variables were slightly more predictive.

Analysis of gene expression following sciatic nerve crush and spinal cord hemisection in the mouse by microarray expression profiling

1. The responses of periphery (PNS) and central nervous systems (CNS) towards nerve injury are different: while injured mammalian periphery nerons can successfully undergo regeneration, axons in the central nervous system are usually not able to regenerate. 2. In the present study, the genes which were differentially expressed in the PNS and CNS following nerve injury were identified and compared by microarray profiling techniques. 3. Sciatic nerve crush and hemisection of the spinal cord of adult mice were used as the models for nerve injury in PNS and CNS respectivey. 4. It was found that of all the genes examined, 14% (80/588) showed changes in expression following either PNS or CNS injury, and only 3% (18/588) showed changes in both types of injuries. 5. Among all the differentially expressed genes, only 8% (6/80) exhibited similar changes in gene expression (either up- or down-regulation) following injury in both PNS and CNS nerve injuries. 6. Our results indicated that microarray expression profiling is an efficient and useful method to identify genes that are involved in the regeneration process following nerve injuries, and several genes which are differentially expressed in the PNS and/or CNS following nerve injuries were identified in the present study.

Relating radiation-induced regional lung injury to changes in pulmonary function tests

PURPOSE

To determine whether the sum of radiotherapy (RT)-induced reductions in regional lung perfusion is quantitatively related to changes in global lung function as assessed by reductions in pulmonary function tests (PFTs).

METHODS AND MATERIALS

Two hundred seven patients (70% with lung cancer) who received incidental partial lung irradiation underwent PFTs (forced expiratory volume in 1 s and diffusion capacity for carbon monoxide) before and repeatedly after RT as part of a prospective clinical study. Regional lung function was serially assessed before and after RT by single photon emission computed tomography perfusion scans. Of these, 53 patients had 105 post-RT evaluations of changes in both regional perfusion and PFTs, were without evidence of intrathoracic disease recurrence that might influence regional perfusion and PFT findings, and were not taking steroids. The summation of the regional functional perfusion changes were compared with changes in PFTs using linear regression analysis.

RESULTS

Follow-up ranged from 3 to 86 months (median 19). Overall, a significant correlation was found between the sum of changes in regional perfusion and the changes in the PFTs (p = 0.002-0.24, depending on the particular PFT index). However, the correlation coefficients were small (r = 0.16-0.41).

CONCLUSIONS

A statistically significant correlation was found between RT-induced changes in regional function (i.e., perfusion) and global function (i.e., PFTs). However, the correlation coefficients are low, making it difficult to relate changes in perfusion to changes in the PFT results. Thus, with our current techniques, the prediction of changes in perfusion alone does not appear to be sufficient to predict the changes in PFTs accurately. Additional studies to clarify the relationship between regional and global lung injury are needed.

[Experimental study of bacteriostatic activity of Chinese herbal medicines on primary cariogenic bacteria in vitro]

OBJECTIVE

To screen some Chinese herbal medicines for their inhibitory activity on cariogenic bacteria, and investigate their active ingredients, and measure their minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC).

METHODS

Active components were isolated from every tested Chinese herbal medicine by means of aqueous extraction and ethanolic extraction. Berberine was purified from Coptis chinensis Fra. Disk agar diffusion method was employed in screening herbs with inhibiting effect on cariogenic bacteria. MIC and MBC were determined by broth dilution method.

RESULTS

Against Streptococcus mutans Ingbritt, MBCs of Magnolia officinalis ethanolic extract, Berberine, Coptis chinensis Fra aqueous extract and Coptis chinensis Fra ethanolic extract were 0.488, 0.625, 7.800 and 1.950 g/L respectively. Against Streptococcus sobrinus 6715, MBCs of Magnolia extract, Coptis chinensis Fra ethanolic extract, Rhus chinensis Mill ethanolic extract and Phellodendron chinen ethanolic extract were 0.488, 0.625, 1.950, 3.900, 3.900 and 3.900 g/L respectively. Against Actinomyces viscosus ATCC 19246, MBCs of Berberine, Coptis chinensis Fra aqueous extract, Coptis chinensis Fra ethanolic extract, Rheum palmatum L aqueous extract and Rheum palmatum L ethanolic extract were 1.250, 3.900, 3.900, 15.600 and 31.250 g/L respectively.

CONCLUSIONS

Magnolia officinalis, Coptis chinensis Fran, Rheum palmatum L aqueous extracts exhibit strong inhibition on cariogenic bacteria. Magnolia officinalis ethanolic extract has the strongest bactericidal effects on Streptococcus mutans and Streptococcus sobrinus.

Occult metastases in sentinel nodes of 200 patients with operable breast cancer

BACKGROUND

Up to 30% of patients with operable breast cancer and negative regional lymph nodes experience disease recurrence within 10 years. Serial sectioning and immunohistochemical staining of these nodes have revealed 9% to 30% occult metastases.

METHODS

Sentinel nodes from 200 patients with T1 and T2 invasive breast carcinoma were step-sectioned at 2- to 3-mm intervals, fixed in 10% formalin, and embedded in paraffin. Sections were taken from the face of the blocks and stained with hematoxylin and eosin (H&E). The blocks were then cut completely, and sections at .25-mm intervals were stained with cytokeratin and examined.

RESULTS

Tumor metastases were found in 34 patients when the sentinel nodes were examined at 2- to 3-mm intervals and in an additional 51 patients when the nodes were sectioned in their entirety at .25-mm intervals and stained with cytokeratin, bringing the total number of patients with metastases to 85. Of the 51 patients whose metastases were detected by 2- to 3-mm sectioning and cytokeratin staining, 27 had isolated tumor cells and 24 had clusters of innumerable malignant cells, all of which were visualized and confirmed by H&E staining of the adjacent sections.

CONCLUSIONS

Histologic examination of sentinel nodes of patients with invasive breast cancer sectioned at 2- to 3-mm intervals and stained with H&E significantly underestimates nodal metastases. Sectioning of the entire sentinel nodes at .25-mm intervals and staining with cytokeratin detects metastases as either isolated cells or as clusters.

Caries experience and oral health behavior in Chinese children with cleft lip and/or palate

PURPOSE

The aims of this study were to investigate whether there were different caries levels in 3- to 6-year-old Chinese children who had a cleft lip compared to those with a cleft lip/palate. The goal also was to evaluate parental attitudes toward the feeding habits and oral health care for their children.

METHODS

A cross-sectional study was carried out through a dental examination of a sample of children and a questionnaire to their parents. A sample of 104 3- to 6-year-old children (66 boys and 38 girls) with cleft lip, cleft palate or both were selected from those receiving pre-surgical treatment. Each child was examined and a short questionnaire was given to parents of the children. The form included questions about infant feeding practices, frequency consumption of specific drinks and, children's toothbrushing frequency.

RESULTS

One hundred and four children were examined. Seventy-five percent had some caries experience and rampant caries was present in 26%. Children with cleft palate had a higher prevalence of rampant caries (30%) compared to those with cleft lip (12%). A multivariate analysis yielded feeding practices and mother's education as the variables significantly associated with caries and rampant caries.

CONCLUSIONS

The results of this study show that: 1. Children with a cleft lip/palate have higher levels of dental caries compared to those with a cleft lip alone; 2. The two most important factors for dental caries were: a. whether the child had been bottle-fed and; b. the educational attainment level of the mother.

Role of mitogen-activated protein kinases in the response of tumor cells to chemotherapy

Antitumor agents, despite having diverse primary mechanisms of action, mediate their effects by inducing apoptosis in tumor cells. Cellular commitment to apoptosis, or the ability to evade apoptosis in response to damage, involves the integration of a complex network of survival and death pathways. Among the best-characterized pathways regulating cell survival and cell death are those mediated by the mitogen-activated protein kinase (MAPK) family. Not surprisingly, MAPK signaling pathways have been implicated in the response of tumor cells to chemotherapeutic drugs. Indeed, literature in this area has grown enormously in recent years, and the present review attempts to provide an overview and perspective of these advances. While the activities of the major MAPK subgroups are subject to modulation upon exposure of different types of cancer cell lines to diverse classes of antitumor agents, the response tend to be context-dependent, and can differ depending on the system and conditions. Despite these complexities, some important trends have surfaced, and molecular connections between MAPK signaling pathways and the apoptotic regulatory machinery are beginning to emerge. With increased evidence supporting a role for MAPK signaling in antitumor drug action, MAPK modulators may have potential as chemotherapeutic drugs themselves or as chemosensitizing agents. The ability of MAPK/ERK kinase (MEK) inhibitors to block survival signaling in specific contexts and promote drug cytotoxicity represents an example, and recent knowledge of the pro-apoptotic functions of JNK and p38 suggests possible new approaches to targeted therapy. However, it will be important first to extrapolate the knowledge gained from these laboratory findings, and begin to address the role of MAPKs in the clinical response to chemotherapeutic drugs.

[Studies on antimicrobial activity of extracts from thyme]

The extracts from thyme by water and ethanol, thyme essential oil, thymol and carvacrol were used as antimicrobial agents in this paper. The results show that all antimicrobial agents used have strong inhibition activity against Staphalococcus aureus, Bacillus subtilis, Escherichia coli.

[Effect of inhibition of polyamine biosynthesis on the growth and telomerase activity of human laryngeal carcinoma cells Hep-2]

OBJECTIVE

To observe the effect of difluoromethylornithine (DFMO), an inhibitor of polyamine biosynthesis, on the growth and telomerase activity of human laryngeal carcinoma cells Hep-2, and try to find a new clue to search for the mechanism of reversion of tumor malignant phenotype via polyamine biosynthesis inhibition.

METHODS

The growth characteristics of Hep-2 cells treated with DFMO were studied by morphological observation, cell growth curve and FCM analysis. Telomerase activity was detected by Telomerase Repeat Amplification Protocol (TRAP).

RESULTS

The inhibition of cell proliferation, a marked increase in G1 and a decrease in S phase populations in the cell cycle of 2.5 mmol/L or 5 mmol/L DFMO treated Hep-2 cells were demonstrated; The cell apoptosis was shown by cell morphology and apoptosis peak in FCM; The telomerase activity of the treated cells was suppressed, while these changes were prevented by provision of exogenous putrescine(Pu) along with DFMO.

CONCLUSION

Inhibition of polyamine biosynthesis could result in the proliferation inhibition and apoptosis induction of Hep-2 cells, which was associated with suppressed telomerase activity. It is suggested that inactivation of telomerase would be one of the important molecular events in reversion of tumor malignant phenotype via inhibition of polyamine biosynthesis.

Experiences from a school-based oral health promotion programme in Wuhan City, PR China

OBJECTIVES

To evaluate the effect of a six-year oral health promotion programme for school children of Wuhan City, PR China.

METHODS

The programme group (P-group) comprised 233 children who had just entered grade 1 (1989). The programme provided an oral health promotion programme, and 215 12-year-old children from three schools participated as a control group (C-group). After the 6-year period of the programme (1995), all of the children had a clinical examination according to the criteria of the WHO and responded to a structured questionnaire on dental health behaviour.

RESULTS

The results showed that attitudes to dental care, regular tooth brushing habits, use of fluoridated toothpaste, gingival health and dental visits, frequencies of consuming sugary drinks/foods were improved in the p-group when compared with the C-group.

CONCLUSION

The school-based oral health promotion programme should be expanded.

Oral health status of heroin users in a rehabilitation centre in Hubei province, China

OBJECTIVE

To report on the oral health of heroin users and to determine risk factors for oral health status.

DESIGN

All heroin users at one rehabilitation camp received an interview using a pre-tested questionnaire from one of three trained interviewers and a dental examination using World Health Organization recommended procedures from one of three calibrated dentists.

SETTING

Interviews and examinations were carried out at Hubei Province camp.

PARTICIPANTS

All 520 resident heroin users at the camp participated in the study.

OUTCOME MEASURES

Oral hygiene expressed using the Debris Index; caries status by DMFT; periodontal status by percentage with bleeding, pocketing and calculus; mucosal status using standard World Health Organization criteria.

RESULTS

One hundred (19%) of the heroin users were caries free; their mean DMFT was 4.2. The majority (92%) of the DMFT was decay and only a small proportion (8%) was treatment related. The proportion of heroin users with bleeding, calculus, shallow pocketing and deep pocketing was 42%, 95%, 42% and 8% respectively. The mean Debris Index score was 3.2. Mucosal lesions were present in 31 subjects (6%). Using multivariate analysis, duration of heroin use and education were risk factors for DMFT, route of drug administration was a risk factor for calculus and gender was a risk factor for deep pocketing.

CONCLUSIONS

There are indications of poorer periodontal health as well as higher caries experience in this group when compared to provincial dental epidemiological data. Mucosal lesions were not widely prevalent. Both social factors and characteristics of drug use were related to oral health in this group.

The c-Jun NH(2)-terminal protein kinase/AP-1 pathway is required for efficient apoptosis induced by vinblastine

Vinblastine is an important antitumor agent that induces G(2)-M arrest and subsequent apoptosis in a wide variety of cell lines, but the molecular mechanisms that link mitotic arrest and apoptosis are poorly understood. The AP-1 transcription factor has been implicated in many critical cellular processes, including apoptosis, and is a major target of the c-Jun NH(2)-terminal kinase signaling pathway that is activated by vinblastine and other microtubule inhibitors. In this study we sought to determine the role of c-Jun NH(2)-terminal kinase/AP-1 in the response of KB3 carcinoma cells to vinblastine. For this purpose, we generated KB3 cell lines that stably expressed the c-Jun dominant-negative deletional mutant TAM67, which lacks the NH(2)-terminal transactivation domain. KB3-TAM67 cell lines displayed normal growth kinetics and essentially unaltered basal AP-1 activity, but vinblastine-induced phosphorylation of c-Jun and activating transcription factor-2, and AP-1 activation, were strongly inhibited. KB3-TAM67 cell lines arrested normally at G(2)-M in response to vinblastine, but were significantly more resistant to the drug, exhibiting markedly delayed apoptosis and increased overall survival, relative to control cells. To investigate the underlying mechanisms, differential expression of apoptotic regulatory genes was monitored by immunoblot and cDNA microarray analysis. We found that vinblastine treatment caused down-regulation of p53 and its target p21 and up-regulation of tumor necrosis factor alpha, Bak, and several other genes in control but not in KB3-TAM67 cells, identifying these genes as putative targets of vinblastine-inducible AP-1. These results demonstrate that vinblastine-inducible AP-1 plays a destructive, proapoptotic role and may do so by regulating the expression of a specific subset of target genes that promotes efficient apoptotic cell death following mitotic arrest.

[Correlation between enhanced anoxic tolerance induced by hypoxic preconditioning and the stability of mitochondrial membrane potential in cultured hypothalamic cells]

The relationship between enhanced anoxic tolerance induced by hypoxic preconditioning and mitochondrial membrane potential (MMP) was studied in cultured hypothalamic cells. Dynamic changes in MMP were monitored by confocal laser scanning microscopy and expression of B-cell lymphoma/leukemia-2 (bcl-2) was examined by flowcytometry. Hypoxic preconditioning increased the cell survival rate and decreased the lactate dehydrogenase leakage under acute anoxia, in addition to maintaining MMP at a relatively higher level and inducing bcl-2 overexpression during anoxia. The results suggest that hypoxic preconditioning can enhance the tolerance of hypothalamic cells to anoxia, and the underlying mechanism may be related to increased stability of MMP. Overexpression of bcl-2 induced by hypoxic preconditioning may play a role in sustaining the stability of MMP.

Global stability of an SEIS epidemic model with recruitment and a varying total population size

This paper considers an SEIS epidemic model that incorporates constant recruitment, disease-caused death and disease latency. The incidence term is of the bilinear mass-action form. It is shown that the global dynamics is completely determined by the basic reproduction number R(0). If R(0)<or=1, the disease-free equilibrium is globally stable and the disease dies out. If R(0)>1, a unique endemic equilibrium is globally stable in the interior of the feasible region and the disease persists at the endemic equilibrium.

[Effects of immune bovine whey on sucrose-dependent adherence of Streptococcus mutans]

OBJECTIVE

The aim of this experiment is to explore the possible anti-carious mechanisms of immune bovine whey.

METHODS

The immune milk was collected from cows immunized with cell associated glucosyltransferase(GFT) over-expression strain B-29-33 of Streptococcus mutans(S. mutans) MT8148. The control milk was obtained from non-immunized cows. The immune and control bovine whey were prepared by removing fat and casein. The effects of two kinds of bovine whey on sucrose-dependent adherence of S. mutans MT8148 were examined by using TTY media with five different volumes of the immune and the control milk, 100, 300, 500, 700 and 900 microliters respectively. The adherent rates were determined by reading the optical density. The adherent morphology was observed by using a scanning electron microscope(SEM).

RESULTS

There was no significant difference in adherence of S. mutans MT8148 cells to the smooth glass surface among five doses with those of the control whey. The immune bovine whey inhibited the adherence of S. mutans. The adherent percentage was 84.37% at 100 microliters and decreased by 58.59% at 900 microliters. The inhibition was does-dependent. The difference of adherent morphology between the immune and control whey was noticeable at 900 microliters. The SEM revealed that cells of S. mutans MT8148 with the control whey were covered by large quantities of gelatinous material, but cells with the immune whey were clearly distinguished.

CONCLUSION

The immune whey has inhibitory potential against the sucrose-dependent adherence of S. mutans.

[Identification of quantitative trait loci associated with fruit traits in watermelon [Citullus lanantus (Thanb) Mansf] and analysis of their genetic effects]

In this study, we mapped and characterized quantitative trait loci (QTL) affecting watermelon fruit traits. A total of 118 F2 progenies derived from the cross 97103 (which is a cultivar with higher total soluble solids concentration, thin rind, susceptible to Fusarium wilt disease) x PI296341(which is a wild germplasm with lower total soluble solids concentration, thick rind, resistant to Fusarium wilt disease) were used to construct a 96-markers map in watermelon. By using interval mapping 4 QTLs for total soluble solids concentration, 5 QTLs for hardness of rind, 2 QTLs for thickness of rind, 3 QTLs for weight of simple fruit, and 6 QTLs for weight of one thousand grain seeds were identified. In addition, the explained variations, additive effects and dominance effects for all detected QTLs were analyzed.

[Expression of transforming growth factor-beta 1 mRNA during mouse molar morphogenesis]

OBJECTIVE

To investigate the temporal and spatial expression and localization of transforming growth factor-beta 1 mRNA during mouse molar morphogenesis.

METHODS

The distribution pattern of TGF-beta 1 mRNA was analysed on 5 microns serial sections of paraformaldehyde-fixed and paraffin-embedded embryonic mouse heads or mandibles using in situ hybridization.

RESULTS

The results show that TGF-beta 1 mRNA was expressed during mouse molar morphogenesis in a temporally and spatially regulated fashion. Local expression of TGF-beta 1 mRNA in the dental epithelium at bud-staged (E13) and cap-staged (E15) teeth were observed. During bell stage (E16-18), TGF-beta 1 mRNA was very abundant in the ameloblast layer and dental papilla cells. The expression of TGF-beta 1 was increased in the layer of odontoblast and ameloblast with the differentiation of these cells.

CONCLUSIONS

These results suggest that TGF-beta 1 may have an important role in tooth morphogenesis, and TGF-beta 1 acts as a paracrine and autoinducing factor.

[Hypoxic preconditioning enhances hypoxic tolerance of hippocampal neurons and synaptic function of rat]

Hypoxic preconditioning with different simulated altitudes (3,000 m and 5,000 m) was performed on Wistar rats and the evoked population spikes were recorded from the hippocampal slices of these rats. The results showed that the appearance of hypoxic injury potential (HIP) and the disappearance of presynaptic volley (PV) were significantly delayed in response to acute lethal hypoxia. HIP and PV delay became more apparent when the hypoxic preconditioning altitude was increased from 3,000 m to 5,000 m. After reoxygenation, the recovery rate of PV in hypoxic preconditioning groups at 3,000 m and 5,000 m was apparently higher than that of control. The above results suggest that hypoxic preconditioning of animals in vivo increases hypoxic tolerance of hippocampal neurons.

IL-10 gene knockout attenuates allergen-induced airway hyperresponsiveness in C57BL/6 mice

Intratracheal administration of interleukin-10 (IL-10) has been reported to inhibit allergic inflammation but augment airway hyperresponsiveness (AHR). In the present study, airway and smooth muscle responsiveness to methacholine (MCh) were compared in wild-type (WT) and IL-10-deficient (IL-10-KO) mice to investigate the role of endogenous IL-10 in AHR development. Naive WT and IL-10-KO mice exhibited similar dose-dependent increases in airway resistance (Raw) to intravenous MCh. Sensitization and challenge with ragweed (RW) induced a twofold increase in responsiveness to intravenous MCh in WT mice, but hyperresponsiveness was not observed in similarly treated IL-10-KO mice. Likewise, tracheal rings from RW-sensitized and -challenged WT mice exhibited a fourfold greater responsiveness to MCh than IL-10-KO tracheal preparations. Measurements of airway constriction by whole body plethysmography further supported the Raw and tracheal ring data (i.e., AHR was not observed in the absence of IL-10). Interestingly, factors previously implicated in the development of AHR, including IL-4, IL-5, IL-13, IgA, IgG1, IgE, eosinophilia, and lymphocyte recruitment to the airways, were upregulated in the IL-10-KO mice. Treatment with recombinant murine IL-10 at the time of allergen challenge reduced the magnitude of inflammation but reinstated AHR development in IL-10-KO mice. Adoptive transfer of mononuclear splenocytes to IL-10-sufficient severe combined immunodeficient mice indicated that lymphocytes were an important source of the IL-10 impacting AHR development. These results provide evidence that IL-10 expression promotes the development of allergen-induced smooth muscle hyperresponsiveness.

Can we predict radiation-induced changes in pulmonary function based on the sum of predicted regional dysfunction?

PURPOSE

To determine whether changes in whole-lung pulmonary function test (PFT) values are related to the sum of predicted radiation therapy (RT)-induced changes in regional lung perfusion.

PATIENTS AND METHODS

Between 1991 and 1998, 96 patients (61% with lung cancer) who were receiving incidental partial lung irradiation were studied prospectively. The patients were assessed with pre- and post-RT PFTs (forced expiratory volume in one second [FEV1] and diffusion capacity for carbon monoxide [DLCO]) for at least a 6-month follow-up period, and patients were excluded if it was determined that intrathoracic recurrence had an impact on lung function. The maximal declines in PFT values were noted. A dose-response model based on RT-induced reduction in regional perfusion (function) was used to predict regional dysfunction. The predicted decline in pulmonary function was calculated as the weighted sum of the predicted regional injuries: equation [see text] where Vd is the volume of lung irradiated to dose d, and Rd is the reduction in regional perfusion anticipated at dose d.

RESULTS

The relationship between the predicted and measured reduction in PFT values was significant for uncorrected DLCO (P = .005) and borderline significant for DLCO (P = .06) and FEV1 (P = .08). However, the correlation coefficients were small (range,.18 to.30). In patients with lung cancer, the correlation coefficients improved as the number of follow-up evaluations increased (range,.43 to.60), especially when patients with hypoperfusion in the lung adjacent to a central mediastinal/hilar thoracic mass were excluded (range,.59 to.91).

CONCLUSION

The sum of predicted RT-induced changes in regional perfusion is related to RT-induced changes in pulmonary function. In many patients, however, the percentage of variation explained is small, which renders accurate predictions difficult.

Construction and in vitro expression of Streptococcus mutans surface protein encoding DNA vaccine

DNA vaccine plasmids were constructed that encoded two highly-conservative regions of a surface protein, PAc, from the human major cariogenic bacterium, Streptococcus mutans. Antigen expression was evaluated in vitro by immunohistochemical analysis of human endothelial cells following cationic liposome-mediated transient transfection with recombinant plasmid. The results of this study provided a basis for further testing of these recombinant plasmids in primates and for efficacy testing of dental caries DNA vaccines in human volunteers in future.

Modulation of mitogen-activated protein kinases and phosphorylation of Bcl-2 by vinblastine represent persistent forms of normal fluctuations at G2-M1

Microtubule inhibitors, widely used in cancer chemotherapy, induce G2-M arrest and apoptosis and have in common the ability to stimulate Raf-1/Bcl-2 phosphorylation and activate c-Jun NH2-terminal protein kinase (JNK). These signal transduction pathways are thought to be activated in response to microtubule damage to promote apoptosis. However, Bcl-2 phosphorylation has been reported to occur at G2-M in nonapoptotic cells, raising the possibility that this and perhaps other signaling pathways altered by microtubule inhibitors reflect perturbations of normal mitotic events. In this study, we sought to test this hypothesis. We show that Bcl-2 phosphorylation and JNK activation, as well as extracellular response kinase and p38 inactivation, occur not only in response to vinblastine but also as discrete transient events at G2-M phase in untreated synchronized KB-3 cells. Thus, modulation of these pathways is not a response to microtubule damage; rather they occur normally at G2-M, and it is the extent, duration, and/or irreversible nature of the signals that distinguish a preapoptotic cell from one destined to divide. These findings provide novel insight into the relationship between mitotic and apoptotic signaling and the mechanism of action of antimitotic drugs.

Immunolocalization of heat shock protein 70 during reparative dentinogenesis

OBJECTIVE

To investigate the immunolocalization of heat shock protein 70 (hsp 70) during reparative formation and to discuss the role of heat shock response in dental pulp injury and repair.

METHODS

A single cavity was prepared in the mesial surface of the first molars of both maxilla and mandible in Wistar rat. The animals were sacrificed at 3, 15, and 30 days post-operation. After the histological process, the paraffin sections were reacted with monoclonal antibodies against rat hsp 70 using the strept-avidin-biotin-peroxidase complex method.

RESULTS

Immunolocalization demonstrated heavy staining for hsp 70 in normal pulp and at different stages of dental pulp repair. In normal pulp, immunoreactivity was visualized in the odontoblasts and the pulp fibroblast. In the group sacrificed at 3 days, heavy staining was located in the odontoblast process and cytoplasm. After 15 days, the newly formed odontoblast-like cells were strongly stained. At 30 days, the same staining intensity was observed in odontoblast-like cells and in pulp cells. No staining was seen in reparative dentin.

CONCLUSION

These results demonstrated that heat shock protein 70 might play an important role as a molecular chaperone during reparative dentin formation.

[Effects of hypoxic preconditioning on anoxic tolerance and IL-1 beta expression in cultured rat hippocampal neurons]

AIM

To study the effects of hypoxic-preconditioning on anoxia-tolerance and IL-1 beta expression in cultured rat hippocampal neurons after anoxia.

METHODS

12 day cultured hippocampal neurons in control and hypoxic-preconditioning group were exposed to anoxic environment(0.9 L/LN2 + 0.1 L/LCO2) for 2, 4, 8 and 12 h. The neurons were immunocytochemically stained using the anti-serum against rhIL-1 beta, The number of survival neurons and the mean optical density (OD) of IL-1 beta expression were investigated.

RESULTS

The morphological changes and IL-1 beta expression induced by acute anoxia in hypoxic-preconditioning neurons were significantly less than those in control. The number of survival neurons was higher in the hypoxia-preconditioning group than that in control group after acute hypoxia.

CONCLUSION

Hypoxia-preconditioning can induce the development of anoxia-tolerance in cultured hippocampal neurons. The decreased IL-1 beta in hippocampal neurons may be an adaptive reaction to acute anoxia.

Production of monoclonal antibody to deltorphin-I and its immunocytochemical application to adult rat brain and cultured rat brain neurons

A monoclonal anti-deltorphin-I antibody specifically recognizing its NH2-terminal region was produced. In the adult rat brain sections, it recognized immunoreactive nerve fibers mainly in the bed nucleus of stria terminalis, central nucleus of amygdala, lateral hypothalamus, hippocampus, substantia nigra, periaqueductal gray and locus ceruleus. Occasionally, positive somata were localized in the bed nucleus of stria terminalis, central nucleus of amygdala, supraoptic and periventricular nuclei. In primarily cultured neurons from various brain regions of new-born rats, the antibody immunostained strongly neuronal somata and processes. The abundant DADTI-immunoreactive substance in the cultured neurons promises to provide an alternative pathway to search for the counterpart of deltorphins in mammals.

Stereotactically guided laser therapy of occult breast tumors: work-in-progress report

HYPOTHESIS

Mammographically detected breast tumors can be completely ablated with laser energy.

DESIGN

Nonrandomized control trial.

SETTING

A university hospital ambulatory care center.

PATIENTS

Thirty-six patients with mammographically detected well-defined breast tumors were selected.

INTERVENTIONS

The diagnosis of malignant neoplasms and determination of prognostic factors were established by image-guided needle-core biopsy. Patients were treated on a stereotactic table, using a 16- to 18-gauge laser probe, with an optic fiber transmitting a predetermined amount of laser energy. A multisensor thermal probe was inserted into the breast adjacent to the laser probe to monitor treatment. In the last 10 patients, the tumor blood flow was evaluated before and after laser therapy with contrast-enhanced color Doppler ultrasound. One to 8 weeks after laser therapy, the tumors were surgically removed and serially sectioned.

MAIN OUTCOME MEASURE

Complete necrosis in 66% of tumors.

RESULTS

Total tumor ablation with negative margins was observed whenever 2500 J/mL of tumor was given or the thermal sensors recorded 60 degrees C. Microscopic examination at 1 week showed disintegration of malignant cells, with peripheral acute inflammatory response and at 4 to 8 weeks extensive fibrosis. Contrast-enhanced color Doppler ultrasound revealed loss of tumor circulation after therapy, and positron emission tomography scan correlated well with histologic findings. There were no systemic adverse effects. Two patients sustained 3 x 4-mm skin burns around the laser needle.

CONCLUSION

A stereotactically guided minimally invasive technique may be effective for the treatment of mammographically detected breast cancer.

[The effect of immune bovine whey on cell-associated glucosyltransferase activity of Streptococcus mutans]

OBJECTIVE

To study the effect of immune bovine whey on cell-associated glucosyltransferase (GTF) activity of S. mutans MT8148.

METHODS

The immune milk was collected from cows immunized with cell-associated GTF overexpression strain B-29-33 of S. mutans MT8148. The control milk was from non-immunized cows. The immune absorbed whey was gotten from immune bovine whey which was absorbed with lyophilized Formalin-killed B-29 whole cells. Three kinds of whey were subdivided into three groups: 50 microliters, 70 microliters, 90 microliters. The content of insoluble glucan was estimated colorimetrically by anthrone method.

RESULTS

The control bovine whey had an enhancing GTF activity (407.00%-485.62%). The immune absorbed whey inhibited partly the enhancing GTF activity (208.74%-273.00%). The immune whey inhibited significantly the GTF activity (70.24%-38.62%) and the inhibition showed a tendency to depend on doses.

CONCLUSIONS

The immune bovine whey inhibits significantly the cell-associated GTF activity of S. mutans MT8148.

Main-group-element calix[4]arenes: variable coordination and conformational isomerism at phosphorus and silicon

Treatment of calix[4]arene (1b) with trichloromethylsilane yields two conformers of calix[4]SiMe(OH), the cone 2b-C and the partial cone 2b-PC. These are isolated and structurally characterized, and their thermodynamic activation parameters are determined in solution [Ea = 117(3) kJ/mol, delta H = 5(4) kJ/mol]. Similar parameters are found for the p-tert-butylcalix[4]arene analogues 2a-C and 2a-PC. Deprotonation of 2b with butyllithium yields calix[4]SiMe(OLi) (8b). The structure of 8b is solvent dependent: 8b contains a five-coordinate silicon in THF and a four-coordinate silicon in benzene. Similar behavior is found for the p-tert-butylcalix[4]arene analogues. The five-coordinate phosphorus analogue of the anion in 8, p-tert-butylcalix[4]PMe (11a), is synthesized from the phosphonium triflate salt p-tert-butylcalix[4]PMe(OH)OTf (10a(OTf)) via treatment with butyllithium. The structure of 11a shows the geometry around phosphorus to be very close to a pure trigonal bipyramid. The X-ray structure of 10a(OTf) cannot be obtained, but its iodide analogue 10a(T) is synthesized and structurally characterized. The cation in 10a(I) adopts the partial cone conformation in the solid state, similar to 2b-PC. Treatment of 8b with methyl trifluoromethanesulfonate yields the methyl phenyl ether calix[4]SiMe(OMe) (3b). This species and its p-tert-butyl analogue 3a are structurally characterized. Both adopt the partial cone conformation. The SiMe group in 3b can be removed via treatment with fluoride to yield the monomethylated calix[4]arene 4b in 50-60% overall yield based on 1b.

Accumulation of RXR alpha during activation of cycling human T lymphocytes: modulation of RXRE transactivation function by mitogen-activated protein kinase pathways

We have previously reported that the activation of resting human immature peripheral blood T (PBT) lymphocytes is associated with the loss of retinoid X receptor alpha (RXRalpha) expression. In the present study, we have demonstrated that, unlike resting cells, activation of cycling human mature PBT lymphocytes, and T lymphocyte leukemia cell lines is accompanied by the accumulation of RXRalpha mRNA and protein. Interestingly, cyclosporin A further augmented RXRalpha expression, indicating the involvement of calcineurin pathways in the process. 9-cis retinoic acid inhibited the accumulation, suggesting that retinoids can regulate the synthesis of their own receptors during T cell activation. Transfection analysis in Jurkat cells, using RXRE-dependent reporter assays, showed that RXRalpha accumulated during T cell activation was transcriptionally inactive. To investigate the mechanism of such inhibition, the role of two mitogen-activated protein kinase pathways, c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK), in modulating RXRE-dependent transcription, was explored. The expression of constitutively active MAP/ERK kinase kinase 1 (MEKK1) inhibited RXRE-dependent transcription, whereas dominant negative MEKK1 increased the transcription, indicating the involvement of JNK signaling pathways in the process. In contrast, expression of constitutively active MEK1, which activates ERK pathway, enhanced RXRE-dependent activation. When both were activated simultaneously, JNK pathway was dominant over ERK pathway and resulted in inhibition of RXRE-mediated transcription. These data demonstrate a dual regulatory control of RXRalpha expression during the activation of resting and cycling T lymphocytes and indicate a dynamic balance between JNK and ERK pathways in modulating RXRE-mediated transactivation.

Oral health services in PR China as evaluated by dentists and patients

OBJECTIVE

To describe the function of oral health services and the delivery of oral health care in PR China.

DESIGN

Cross-sectional surveys. Self-administered questionnaires gathered information on professional practices and attitudes of Chinese dentists. Patients were examined clinically for caries and services rendered. Patients were interviewed about oral health status, reason of dental visits and consumption of services, perceived need for care and self-care practices.

SETTING

Wuhan City of the Hubei Province of China.

SUBJECTS

Random samples of dentists (n = 250) working with child and adult patients in 1998 in Wuhan City. Each dentist had a representative sample of 20 patients attending consecutively for care enrolled in the study.

RESULTS

On average, the dentists saw 12 patients per day, with most time devoted to restorative treatment and extraction. The majority of dentists held the opinion that in China little attention is given to preventive care. Forty per cent of the patients were new to the dentists and more than half attended care because of pain or acute symptoms. The reported mean number of decayed, missing, and filled teeth varied from 2.6 for 12-year-old patients to 10.7 for patients aged 65-74. Daily toothbrushing was practised by more than 90% of the patients in all age groups, however, the tradition of regular dental visits was weak. Most patients (51-75 per cent) attended for care due to acute problems or pain.

CONCLUSION

The study indicated the need for reorientation of the Chinese oral health services towards prevention.

Vinblastine-induced phosphorylation of Bcl-2 and Bcl-XL is mediated by JNK and occurs in parallel with inactivation of the Raf-1/MEK/ERK cascade

Microtubule-damaging agents arrest cells at G(2)/M and induce apoptosis in association with phosphorylation of the anti-apoptotic proteins Bcl-2 and Bcl-X(L). Because microtubule inhibitors activate JNK, we sought to determine whether JNK was responsible for Bcl-2/Bcl-X(L) phosphorylation in KB-3 cells treated with vinblastine. Two major endogenous forms of JNK, p46(JNK1) and p54(JNK2), were present in KB-3 cells, and both isoforms were activated by vinblastine as determined by Mono Q chromatography. We used antisense oligonucleotides (AS) to specifically inhibit their expression. A combination of AS-JNK1 with AS-JNK2 inhibited by 80% vinblastine-induced phosphorylation of two known JNK substrates, c-Jun and ATF-2. In addition, AS-JNK1/2 inhibited vinblastine-induced phosphorylation of Bcl-2 by 85% and that of Bcl-X(L) by 65%. Stable expression of the JNK scaffold protein JIP-1 blocked vinblastine-induced phosphorylation of c-Jun and ATF-2, but did not affect Bcl-2/Bcl-X(L) phosphorylation, confirming a bifurcation in JNK signaling involving both nuclear and non-nuclear substrates. Vinblastine-induced phosphorylation of Raf-1 was unaffected by AS-JNK1/2 and was associated with loss of activity for MEK substrate in vitro and inactivation of ERK in vivo. These results provide evidence for a direct role of the JNK pathway in apoptotic regulation through Bcl-2/Bcl-X(L) phosphorylation.

Neurotransmitters, neuropeptides and calcium binding proteins in developing human cerebellum: a review

Many endogenous neurochemicals that are known to have important functions in the mature central nervous system have also been found in the developing human cerebellum. Cholinergic neurons, as revealed by immunoreactivities towards choline acetyltransferase or acetylcholinesterase, appear early at 23 weeks of gestation in the cerebellar cortex and deep nuclei. Immunoreactivities gradually increase until the first postnatal month. Enkephalin is localized in the developing cerebellum, initially in the fibers of the cortex and deep nuclei at 16-20 weeks and then also in the Purkinje cells, granule cells, basket cells and Golgi cells at 23 weeks onward. Another neuropeptide, substance P, is localized mainly in the fibers of the dentate nucleus from 9 to 24 weeks but substance P immunoreactivity declines thereafter. GABA, an inhibitory neurotransmitter of the central nervous system, starts to appear at 16 weeks in the Purkinje cells, stellate cells, basket cells, mossy fibers and neurons of deep nuclei. GABA expression is gradually upregulated toward term forming networks of GABA-positive fibers and neurons. Catecholaminergic fibers and neurons are also detected in the cortex and deep nuclei at as early as 16 weeks. Calcium binding proteins, calbindin D28K and parvalbumin, make their first appearance in the cortex and deep nuclei at 14 weeks and then their expression decreases toward term, while calretinin appears later at 21 weeks but its expression increases with fetal age. The above findings suggest that many neurotransmitters, neuropeptides and calcium binding proteins (1) appear early during development of the cerebellum; (2) have specific temporal and spatial expression patterns; (3) may have functions other than those found in the mature neural systems; and (4) may be able to interact with each other during early development.

Immunohistochemistry of bone sialoprotein and osteopontin during reparative dentinogenesis in vivo

OBJECTIVE

To investigate the stage-specific and tissue expression of bone sialoprotein (BSP) and osteopontin (OPN) during reparative dentinogenesis in vivo.

METHODS

Direct pulp-capping with Ca(OH)2 developed a model used for the investigation of reparative dentinogenesis in the exposed dental pulp. In this model, standardized class V cavities were prepared close to the gingival margin on the buccal surface of each tooth. Animals were sacrificed 3, 7, and 10 days post-operation. Immunohistochemical staining determined the tissue-specific expression of BSP and OPN during the process.

RESULTS

Odontoblast-like cells and reparative dentin reacted positively with BSP and OPN. The expression of BSP reached a peak at day 7, then gradually decreased, while the expression of OPN showed no significant difference between day 7 and day 10.

CONCLUSION

BSP and OPN may play different roles in reparative dentinogenesis. BSP may serve as a nucleator of hydroxyapatite crystal formation.

In situ hybridization analysis of transforming growth factor-beta 1 RNA expression during mouse tooth development

OBJECTIVE

The aim of this study is to investigate the temporal and spatial expression and localization of transforming growth factor-beta 1 mRNA during mouse tooth development.

METHODS

The distribution pattern of TGF-beta 1 mRNA during tooth development was analyzed on 5 microns serial sections of paraformaldehyde-fixed and paraffin-embedded embryonic mouse heads or mandibles.

RESULTS

The results show that TGF-beta 1 mRNA is expressed during mouse tooth development in a temporally and spatially regulated fashion. Local expression of TGF-beta 1 mRNA in the dental epithelium at budstaged (E13) and capstaged (E15) teeth were observed. During bell stage (E16-18), TGF beta 1 mRNA was very abundant in the ameloblast layer and dental papilla cells. The expression of TGF-beta 1 increased in the layer of odontoblast and ameloblast with the differentiation of these cells.

CONCLUSION

These results suggest that TGF-beta 1 may have an important role in odontogenesis and that it acts as a paracrine and autoinducing factor.

Direct coupling of transcription and mRNA processing through the thermogenic coactivator PGC-1

Transcription and mRNA processing are coupled events in vivo, but the mechanisms that coordinate these processes are largely unknown. PGC-1 is a transcriptional coactivator that plays a major role in the regulation of adaptive thermogenesis. PGC-1 also has certain motifs characteristic of splicing factors. We demonstrate here that mutations in the serine- and arginine-rich domain and RNA recognition motif of PGC-1 interfere with the ability of PGC-1 to induce mRNAs of target genes. These mutations also disrupt the ability of PGC-1 to co-localize and associate with RNA processing factors. PGC-1 can alter the processing of an mRNA, but only when it is loaded onto the promoter of the gene. These data demonstrate the coordinated regulation of RNA transcription and processing through PGC-1.

[Differentiation of achondroplasia and other similar genetic dwarfism by FGFR3 gene analysis]

OBJECTIVE

To study the gene mutation of Chinese patients with achondroplasia(ACH) and to set up a simple and rapid molecular diagnostic method to differentiate ACH from other similar genetic dwarfism.

METHODS

The specific fragment of fibroblast growth factor receptor 3(FGFR3) transmembrane domain was amplified from dried blood spots of 21 patients with ACH and 6 suspicious patients with ACH by polymerase chain reaction, then mutation was screened and detected by restrictive enzyme analysis, single strand conformation polymorphism(SSCP) and denaturing gradient gel electrophoresis(DGGE).

RESULTS

One out of 6 suspicious cases was ACH and 5 were pseudoachondroplasia(PSACH). Twenty-one out of 22 patients with ACH bore a G to A transition at nucleotide 1138 and 1 bore a G to C transversion at this same position.

CONCLUSION

The nucleotide 1138 of FGFR3 gene is also the hotspot of mutation in Chinese patients with ACH. A simple and rapid molecular diagnostic method has been set up to differentiate ACH from other similar genetic dwarfism.

[Responses induced by dopamine in Xenopus laevis oocytes injected with mRNA from heat injured rat striatum]

Poly(A)(+) mRNA isolated from the striatum of normal rats and heat injured rats by RNAgents Total RNA Isolation System and PolyTract mRNA RNAgents Isolation Systems was microinjected into Xenopus laevis oocytes to express functional neurotransmitter receptors. Membrane currents were recorded by the conventional patch clamp technique for measuring the relative amounts of mRNA encoding dopamine receptor in order to study the change in dopamine receptors in heat injured rat striatum. There was no change in resting membrane potentials of the oocytes before and after mRNA injection. Dopamine induced membrane currents were shown to be mediated through Cl( ). The oocytes injected with mRNA from heat injured rat striatum were less sensitive to dopamine than those injected with mRNA from normal rats ( P<0.05). The above result showed that heat injury affected gene expression and signal transduction of dopamine receptors in rat striatum.

Positron emission tomography with fluorine-18 fluorodeoxyglucose to evaluate response of early breast carcinoma treated with stereotaxic interstitial laser therapy

Stereotaxic interstitial laser therapy is a promising new alternative to surgery to treat early-stage breast cancer. With this, laser energy coagulates the tumor with controlled heat, leading to fibrosis. Fluorodeoxyglucose positron emission tomography (FDG PET) scanning was performed in four patients treated by this technique to determine the degree of necrosis after interstitial laser therapy. The results showed that FDG PET scanning was in close agreement with histopathologic findings, confirming complete necrosis in one patient and variable response in the other three patients. Uptake of FDG appears to be a reliable means to monitor treatment response after interstitial laser therapy and may be useful in the management of breast cancer when used with this new procedure.

The role of lung perfusion imaging in predicting the direction of radiation-induced changes in pulmonary function tests

BACKGROUND

The aim of this study was to determine whether preradiation (pre-RT) single photon emission computed tomography (SPECT) lung perfusion scans can be used to predict RT-induced changes in pulmonary function tests (PFTs).

METHODS

Ninety-four patients irradiated for thoracic tumors had pre-RT SPECT lung perfusion scans. The presence of SPECT hypoperfusion distal to a central mediastinal tumor was qualitatively assessed visually without knowledge of PFT changes. Patients were grouped based on whether the diffusion capacity (DLCO) ever increased post-RT. Comparisons of patient groups were performed using 1-tailed Fisher exact tests. Patient follow-up was 6-56 months (mean, 30 months). To assess SPECT hypoperfusion objectively, the average dose to the computed tomography (CT)-defined lung was compared with the weighted-average dose (based on relative perfusion) to the SPECT-defined lung. The ratio between the CT- and SPECT-defined mean lung dose provided a quantitative assessment of hypoperfusion. The mean ratio for patients with central tumor and adjacent hypoperfusion was compared with that of the others (Wilcoxon rank-sum one-sided test).

RESULTS

In patients with central tumors, 41% (9 of 22) with adjacent hypoperfusion had improvements in DLCO following radiation, versus 18% (3 of 17) of those without hypoperfusion (P = 0.11). In patients with lung carcinoma, the corresponding ratios were 40% (8 of 20) and 10% (1 of 10), respectively (P = 0.10). The mean ratio of CT dose to SPECT dose was 1.35 for patients with central tumors and adjacent hypoperfusion versus 1.16 for others (P = 0.017).

CONCLUSIONS

The presence of SPECT hypoperfusion adjacent to a central mediastinal mass may identify patients likely to have improved PFTs following RT. Thus, SPECT imaging may be useful in models for predicting radiation-induced changes in PFTs.

[Periodontal regeneration by application of the porous beta-TCP/BMP artificial bone to Class II furcation defects]

OBJECTIVE

To study the regeneration of periodontal tissue after the application of beta-TCP/BMP artificial bone to class II furcation defects.

METHODS

Periodontal defects were produced surgically around premolar teeth in 4 dogs. The flap surgery was performed and the root surfaces were curetted to remove the periodontal ligament and the cementum. A synthetic bioabsorble barrier manufactured from poly DL-lactide was used. The defects were divided into 3 groups (beta-TCP/BMP + PDLLA, PDLLA, control). 12 weeks after surgery, the animals were sacrificed and the teeth with their supporting periodontium were processed for light microscopic evaluation.

RESULTS

The definitive evidences of regeneration were founded both in BMP/GTR group and GTR group, but the BMP/GTR group exhibited more new bone formation, cementum deposition occupying the majority of the furcation defects than the other two groups.

CONCLUSION

It was concluded that the beta-TCP/BMP artificial bone can be used in GTR technique to promote periodontal regeneration.

Can angiotensin-converting enzyme inhibitors protect against symptomatic radiation pneumonitis?

This study was designed to determine whether patients taking angiotensin-converting enzyme (ACE) inhibitors while receiving radiation therapy for lung cancer are protected from developing symptomatic radiation pneumonitis. The records of 213 eligible patients receiving thoracic irradiation for lung cancer with curative intent at Duke University Medical Center from 1994-1997 were reviewed. Of the 213 patients, 26 (12.2%) were on ACE inhibitors (usually for the management of hypertension) during radiotherapy (group 1); the remaining 187 patients (group 2) were not. Patients were irradiated, with fields shaped to protect normal tissues, with total doses of 50-80 Gy. After treatment, patients were generally followed every 3 months for 2 years, then every 6 months thereafter. Symptomatic radiation pneumonitis was scored according to modified National Cancer Institute Common Toxicity Criteria (i.e., radiographic changes alone were not sufficient for the diagnosis of pneumonitis). There was no difference in the incidence of pneumonitis between the two groups (P = 0.75). Fifteen percent of the patients on ACE inhibitors (group 1) developed symptomatic radiation-induced lung injury compared to 12% of the patients not receiving these drugs (group 2). Although patients in group 1 tended to develop pneumonitis slightly sooner than did patients in group 2, this difference also was not significant (P = 0. 8). Within the dose range prescribed for treating hypertension, ACE inhibitors do not appear to either decrease the incidence or delay the onset of symptomatic radiation pneumonitis among lung cancer patients receiving thoracic irradiation.

[Tissue engineered neo-cartilage using polymer substrates and chondrocytes: experimental study]

OBJECTIVE

To investigate the possibility of using poly beta-hydroxybutyrate (PHB) as a scaffold for chondrocytes and the feasibility of generating tissue engineered cartilage in rabbit animal model.

METHODS

The articular cartilage from 4-week-old rabbits was enzymatically dissolved by type II collagenase, and chondrocytes were harvested and seeded into foams of PHB. After incubation for 1 week in vitro, chondrocyte-polymer constructs were implanted subcutaneously into rabbits. Two respective control groups were established by subcutaneous implantation of PHB foams and chondrocytes alone. The rabbits were killed at 4, 8, 12 weeks postoperatively, and the specimens were dissected and examined macroscopically, histologically and immunohistochemically.

RESULTS

Specimens harvested from chondrocyte-polymer constructs and subjected to gross morphologic and histologic analysis demonstrated new cartilage formation, and those from control groups showed no cartilage formation.

CONCLUSION

These findings demonstrate that the foam of PHB is not only a good "matrix" for cartilage tissue engineering, but also optimal scalffold for the seeding of chondrocytes to generate new cartilage that would be useful in plastic and reconstructive surgery.

Radiation-induced pulmonary injury: symptomatic versus subclinical endpoints

PURPOSE

To assess the relationship between radiation (RT)-induced pulmonary symptoms and subclinical changes in pulmonary functions tests (PFT) and radiographs.

MATERIALS AND METHODS

A total of 184 patients irradiated between 1992 and 1998 were prospectively evaluated for RT-induced pulmonary symptoms, changes in computed tomography (CT) density, reductions in single photon emission CT (SPECT) perfusion, and changes in pulmonary functions tests (forced expiratory volume in 1 s [FEV1] and diffusion capacity to carbon monoxide [DLCO]). Comparisons between the evaluable patients with (N=34) and without (N=106) RT-induced pulmonary symptoms were made.

RESULTS

Within 6 months of RT, 80% of the RT-induced symptoms were noted. There was no association between the presence or absence of RT-induced pulmonary symptoms and the frequency of RT-induced radiographic changes (p=0.53), or in the dose-response curve for RT-induced reductions in regional perfusion. Overall, RT-induced changes in SPECT images were more commonly seen than increased density changes on CT (p<0.001). Most patients with pulmonary symptoms had relatively low pre-RT PFTs and experienced further declines following RT.

CONCLUSIONS

Regional radiographic changes in CT-defined tissue density or SPECT-defined tissue perfusion are similar in patients with and without RT-induced pulmonary symptoms because these endpoints do not consider the volume of lung affected. RT-induced pulmonary symptoms are better related to post-RT PFT because they are an assessment of whole lung function. Additional studies are necessary to better define models that can predict the degree of radiation-induced changes in whole lung function.

[Difluoromethylornithine synergizes with antisense bcl-2 RNA in the induction of apoptosis of HL60 cells]

OBJECTIVE

To study the combined effect of difluoromethylornithine (DFMO) and bcl-2 antisense RNA in the induction of apoptosis of HL60 cells.

METHODS

HL60 cells were transfected with recombinant retroviral vector expressing bcl-2 antisense RNA. The growth characteristics of transfectants were studied by morphological observation, growth curve, FCM analysis, colony formation in soft agar, DNA electrophoresis, molecular hybridization and immunocytochemical staining.

RESULTS

The recombinant retroviral vectors expressing bcl-2 antisense RNA and the cell line producing recombinant virus were constructed. Although the expression of bcl-2 at mRNA and protein levels in the HL60 cells transfected with antisense bcl-2 were down-regulated, there was no change in cell growth, cell cycles and expression of ornithine decarboxylase (ODC) compared with the parental cells albeit some decrease in colony formation. In addition, transfection with antisense bcl-2 did not induce marked apoptosis whereas treatment of the transfectant with low concentration (0.2 mmol/L) of DFMO resulted in enhanced expression inhibition of bcl-2 protein, inhibition of cell growth and induction of apoptosis.

CONCLUSION

DFMO synergizes with antiense bcl-2 RNA in the induction of apoptosis of HL60 cells.