Risk factor analysis and nomogram construction in patients with distant metastatic prostate cancer at different PSA levels: a study based on the SEER database

OBJECTIVE

Prostate cancer (PCa) is the most common malignant tumor in the male genitourinary system. Once PCa has metastasized, it is very difficult to cure. The purpose of this study was to investigate the prognostic risk factor analysis of patients with different prostate-specific antigen (PSA) levels in distant metastatic PCa. At the same time, we construct effective models for predicting the survival rate of prostate cancer patients.

PATIENTS AND METHODS

Data on prostate cancer patients with the presence of distant metastases were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. PCa patients with distant metastases were categorized into two groups based on PSA levels, one with PSA <20 ng/mL and the other with PSA ≥20 ng/mL. Univariate and multivariate COX regression analyses were used to identify independent factors affecting the prognosis of the patients. A nomogram was constructed using the independent prognostic factors, and the results were evaluated using calibration curves, timeROC curves, and Kaplan-Meier curves.

RESULTS

In the PSA <20 ng/mL group, there were a total of 1,832 patients. COX regression analysis showed that age, marital status, N stage, grade, Gleason score, and medical household income inflation were independent prognostic factors for overall survival (OS) in patients. In addition, we found that age, marital status, N stage, bone metastasis, grade, and Gleason score were independent prognostic factors for cancer-specific survival (CSS) in patients. In the PSA ≥20 ng/mL group, there were a total of 5,314 patients. It was found that age, ethnicity, marital status, bone metastasis, first malignant primary indicator, grade, Gleason score, and medical household income inflation were patients' independent prognostic factors for OS. For CSS, we found that age, ethnicity, marital status, T stage, radiotherapy, bone metastasis, Gleason score, and Median household income inflation were independent prognostic factors. Constructing a nomogram can accurately predict the prognosis of this group of patients.

CONCLUSIONS

We found different independent prognostic factors for different PSA levels in patients with distant metastatic PCa. A new nomogram was constructed to predict OS and CSS in patients, which helps in clinical-assisted decision-making.

A comprehensive analysis of essential meiotic endonuclease 1 to prognosis and immune infiltration in kidney renal clear cell carcinoma

OBJECTIVE

Clear cell renal cell carcinoma (ccRCC) is the most common type of cancer, and its molecular pathogenesis is unclear. In this study, we investigated the prognostic value of essential meiotic endonuclease 1 (EME1) in kidney renal clear cell carcinoma (KIRC).

MATERIALS AND METHODS

We downloaded the RNA-Seq expression of 526 KIRC tissues and 72 normal tissues from the TCGA database and the corresponding clinical data. The gene expression profiles associated with four clear cell renal cell carcinomas were downloaded from the GEO database for analysis. The expression of EME1 in clear renal cell carcinoma and its correlation with the clinical baseline data were analyzed. Kaplan-Meier survival curve analysis was performed to assess the relationship between EME1 and patient survival. Enrichment analysis was performed to elucidate the possible functions of EME1. We also analyzed the relationship between the EME1 expression and immune infiltration through TIMER2.0 and TISIDB online databases as well as the relationship between EME1 and common immune checkpoints.

RESULTS

EME1 was identified as a risk factor for overall survival in clear cell renal cell carcinoma with a hazard ratio of 3.201 (95% confidence interval: 2.430-4.215; p < 0.001). EME1 was highly expressed in KIRC compared to that in normal tissues (p < 0.001) and in the worse TNM stages and late stages (stage 3/4) (p < 0.001). High EME1 expression was strongly associated with the advanced T stage (p = 0.003), advanced N stage (p = 0.002), and advanced M stage (p = 0.006). Research data on KIRC were simultaneously collected and analyzed from the GEO database, including GSE40435, GSE53000, GSE68417, and GSE53757. EME1 predicted the survival status in KIRC patients (AUC = 0.62). We further established a nomogram including the correlation between the high and low EME1 expression, and EME1 was found to contribute to the prediction of the probability of patient survival with a c-index = 0.796. Kaplan-Meier analysis revealed a lower likelihood of survival with a high EME1 expression (p < 0.001). In addition, further bioinformatics analysis suggested that EME1 may be associated with the extent of immune infiltration in KIRC.

CONCLUSIONS

An increased expression of EME1 in KIRC is thus associated with advanced clinicopathological features, possibly acting as a potential biomarker of poor prognosis in KIRC.

Known classes aware and emerging unknown classes rejection based on adversarial training for open set fault diagnosis

Most domain adaptation diagnosis approaches presume that the label spaces of different domains are identical. However, novel fault states may emerge in real-world applications, and traditional closed-set approaches only rely on marginal distribution alignment, making them difficult to resolve the open-set domain adaptation issue. One typical open-set problem is that the label spaces of the source and target domains are partially overlapped. To tackle this issue, this paper proposes an approach called known classes aware and emerging unknown classes rejection (KAEUR) based on adversarial training. First, an adaptive weighted learning scheme based on the entropy is introduced to the maximum classifier discrepancy method, which aims to align the target known-type samples with each class of the source known-type samples and suppress the influence of unknown-type samples during feature alignment, thereby extracting domain-invariant features through interactive adversarial training. Second, two binary cross-entropy schemes and the entropy modules are constructed to enhance the divergence between the known and unknown types. Then, an integrated criterion is established to reject the target unknown classes. Finally, three machinery datasets are constructed to demonstrate the effectiveness and superior performance of the proposed approach.

Partial adversarial domain adaptation by dual-domain alignment for fault diagnosis of rotating machines

Domain adaptation (DA) techniques have succeeded in solving domain shift problem for fault diagnosis (FD), where the research assumption is that the target domain (TD) and source domain (SD) share identical label spaces. However, when the SD label spaces subsume the TD, heterogeneity occurs, which is a partial domain adaptation (PDA) problem. In this paper, we propose a dual-domain alignment approach for partial adversarial DA (DDA-PADA) for FD, including (1) traditional domain-adversarial neural network (DANN) modules (feature extractors, feature classifiers and a domain discriminator); (2) a SD alignment (SDA) module designed based on the feature alignment of SD extracted in two stages; and (3) a cross-domain alignment (CDA) module designed based on the feature alignment of SD and TD extracted in the second stage. Specifically, SDA and CDA are implemented by a unilateral feature alignment approach, which maintains the feature consistency of the SD and attempts to mitigate cross-domain variation by correcting the feature distribution of TD, achieving feature alignment from a dual-domain perspective. Thus, DDA-PADA can effectively align the SD and TD without affecting the feature distribution of SD. Experimental results obtained on two rotating mechanical datasets show that DDA-PADA exhibits satisfactory performance in handling PDA problems. The various analysis results validate the advantages of DDA-PADA.

P1889Quantitative global proteomics and lysine acetylome analysis of changes in left atrial appendage tissue from valvular heart disease patients with atrial fibrillation

Background

Previous studies have shown that acetylation plays a critical role in regulating the progress of cardiovascular diseases by acetylated histone and non-histones protein. However, the global lysine acetylome during atrial fibrillation (AF) were not fully understood.

Purpose

The aim of the present study was to identify the underlying mechanisms of AF via profiling of the quantitative changes of global proteomics and lysine acetylome in the left atrial appendage (LAA) tissues from valvular heart disease patients with AF.

Methods

This study obtained LAA specimens from patients undergoing cardiac surgery for severe valvular heart disease. The LAA specimens were obtained from both 9 patients with AF and with sinus rhythm (SR). The changes of proteome and acetylome in the AF-LAA vs SR-LAA tissues were studied using dimethyl-labeling, HPLC fractionation, affinity enrichment, LC-MS/MS analysis, database Search and bioinformatic analysis. The acetylated levels of each lysine acetylated site were normalized on the basis of the corresponding protein abundance.

Results

The bioinformatic analysis indicates 294 up-regulated (AF/SR ratio >1.3) proteins and 169 down-regulated (AF/SR ratio <1/1.3) proteins in the AF-LAA vs SR-LAA were detected. Moreover, 3,880 sites in 1,044 proteins were quantified. Motif analysis of the identified acetylated peptides indicated that a total of 14 significantly enriched amino acid sequence motifs from −10 to +10 surrounding the acetylated lysine (Kac) were defined according to 3412 peptides from 1115 proteins. Among the quantified acetylated sites and proteins, 231 up-regulated acetylated sites in 130 proteins and 121 down-regulated acetylated sites in 74 proteins were detected. The enrichment-based clustering analysis showed that energy metabolism and cardiac contraction-related proteins were highly differentially expressed in the AF-LAA vs SR-LAA. Meanwhile, the protein-protein interaction network of the differentially expressed acetylated proteins demonstrated that there were 146 nodes and 569 interactions in the network and quite a lot of interactions in energy metabolism-related proteins and in cardiac contraction-related proteins. Furthermore, the acetylated levels of most differentially expressed energy metabolism-related proteins involving in oxidative phosphorylation, TCA cycle, respiratory ETC, fatty acid metabolism were up-regulated. On the contrary, the acetylated levels of most acetylated sites in differentially expressed cardiac contraction-related proteins including the key contraction proteins were down-regulated.

Interaction network of Ac-proteins

Conclusions

This study details and expands our understanding of the changes of proteome and lysine acetylome in the LAA tissues from valvular heart disease patients with AF. The data suggest important expression differences of acetylated proteins related to energy metabolism and cardiac contraction which may be involved in the matrix of AF formation and maintainence.

Acknowledgement/Funding

This work was supported by the grants from the National Natural Science Foundation of China (no. 81600273, no. 81570310, no.81770337 and no.81870258)

Enhanced intrinsic photovoltaic effect in tungsten disulfide nanotubes

The photovoltaic effect in traditional p-n junctions-where a p-type material (with an excess of holes) abuts an n-type material (with an excess of electrons)-involves the light-induced creation of electron-hole pairs and their subsequent separation, generating a current. This photovoltaic effect is particularly important for environmentally benign energy harvesting, and its efficiency has been increased dramatically, almost reaching the theoretical limit¹. Further progress is anticipated by making use of the bulk photovoltaic effect (BPVE)², which does not require a junction and occurs only in crystals with broken inversion symmetry³. However, the practical implementation of the BPVE is hampered by its low efficiency in existing materials^4-10. Semiconductors with reduced dimensionality² or a smaller bandgap^4,5 have been suggested to be more efficient. Transition-metal dichalcogenides (TMDs) are exemplary small-bandgap, two-dimensional semiconductors^11,12 in which various effects have been observed by breaking the inversion symmetry inherent in their bulk crystals^13-15, but the BPVE has not been investigated. Here we report the discovery of the BPVE in devices based on tungsten disulfide, a member of the TMD family. We find that systematically reducing the crystal symmetry beyond mere broken inversion symmetry-moving from a two-dimensional monolayer to a nanotube with polar properties-greatly enhances the BPVE. The photocurrent density thus generated is orders of magnitude larger than that of other BPVE materials. Our findings highlight not only the potential of TMD-based nanomaterials, but also more generally the importance of crystal symmetry reduction in enhancing the efficiency of converting solar to electric power.

Copy number variation of ZNF280AY across 21 cattle breeds and its association with the reproductive traits of Holstein and Simmental bulls

The mammalian Y chromosome gene families in the ampliconic region are expressed predominantly or exclusively in the testis, and their copy number variations (CNV) are significantly associated with male reproductive traits, suggesting they have important roles in spermatogenesis and testicular development. ZNF280AY (zinc finger protein 280A, Y-linked) is a member of the zinc finger protein family and has been identified as a bovid-specific Y-chromosome gene. The current study applied a reliable quantitative real-time PCR method to estimate the CNV of ZNF280AY in 715 bulls across 21 cattle breeds and to further investigate the association of the CNV of ZNF280AY with bull reproductive traits and ZNF280AY mRNA expression levels in adult testis. The results revealed that the median copy number of ZNF280AY was 47, and the copy number varied from 11 to 154, showing significant CNV between and within the investigated cattle breeds. In addition, all 715 bulls were classified into Y1, Y2, and Y3 lineage groups based on a rapid genotyping method described previously. Pairwise comparisons indicated that bulls belonging to the Y1 lineage had a significantly lower median copy number (40) than bulls belonging to the Y2 (52) and Y3 lineages (57). Association analysis revealed that the CNV of ZNF280AY was correlated negatively with the percentage of normal sperm and sperm concentration in Holstein bulls, whereas no significant correlation was observed with ejaculation volume, total sperm count, sperm motility, postthaw motility (PTM), and scrotal circumference in Holstein and Simmental bulls. Furthermore, no correlation was observed between ZNF280AY copy number and ZNF280AY mRNA expression levels in the testis. The current study suggests that the CNV of the ZNF280AY gene family is associated with male reproductive traits and may serve as a valuable marker for early bull fertility selection in Holstein breeding programs.

The retinoblastoma 1 gene (RB1) modulates the proliferation of chicken preadipocytes

1. The objective of this study was to reveal the role of chicken RB1 (Gallus gallus RB1, gRB1) in the proliferation of preadipocytes. 2. To measure gene expression of gRB1 in the proliferation of chicken preadipocyte, quantitative real-time PCR was used. The expression levels of gRB1 transiently increased during this process. 3. To detect the effect of gRB1 on the proliferation of chicken preadipocyte, MTT assay and cell-cycle analysis were performed. MTT assay showed that overexpression of gRB1 significantly suppressed (P < 0.05) the proliferation of chicken preadipocytes, and knockdown of gRB1 promoted the proliferation of chicken preadipocytes. Cell-cycle analysis showed that the proportion of preadipocytes in the G1 and G2 phases significantly increased (P < 0.05), and the proportion of preadipocytes in the S phase significantly decreased (P < .05) after up-regulation of the expression of gRB1. The proportion of preadipocytes in the S phase significantly increased (P < 0.05) after down-regulation of gRB1. 4. Quantitative real-time PCR was used to detect the effect of gRB1 on the expression of genes related to proliferation of chicken preadipocytes. Gene expression analysis showed that gRB1 knockdown promoted markers indicating proliferation of Ki-67 (MKi67) expression at 96 h (P < 0.05), and overexpression of gRB1 reduced MKi67 expression at 72 h (P < 0.05). 5. This study demonstrated that gRB1 inhibited preadipocyte proliferation at least in part by inhibiting the G1 to S phase transition.

Superconductivity in a chiral nanotube

Chirality of materials are known to affect optical, magnetic and electric properties, causing a variety of nontrivial phenomena such as circular dichiroism for chiral molecules, magnetic Skyrmions in chiral magnets and nonreciprocal carrier transport in chiral conductors. On the other hand, effect of chirality on superconducting transport has not been known. Here we report the nonreciprocity of superconductivity—unambiguous evidence of superconductivity reflecting chiral structure in which the forward and backward supercurrent flows are not equivalent because of inversion symmetry breaking. Such superconductivity is realized via ionic gating in individual chiral nanotubes of tungsten disulfide. The nonreciprocal signal is significantly enhanced in the superconducting state, being associated with unprecedented quantum Little-Parks oscillations originating from the interference of supercurrent along the circumference of the nanotube. The present results indicate that the nonreciprocity is a viable approach toward the superconductors with chiral or noncentrosymmetric structures.

Chirality affects many properties of materials, but how it affects superconductivity remains unclear. Here, Qin et al. report nonreciprocal supercurrent flows in individual nanotubes of WS₂ via ionic gating, evidencing chiral superconducting transport.

Factors associated with extended treatment among tuberculosis patients at risk of relapse in California

SETTING

California, United States.

OBJECTIVE

To determine the frequency of tuberculosis (TB) patients at risk for relapse who received at least 9 months of anti-tuberculosis treatment (extended treatment) and to identify factors associated with not receiving extended treatment.

DESIGN

We analyzed characteristics of culture-confirmed pulmonary TB patients reported to the California TB Registry during 2004-2009. Patients with cavities on initial chest radiograph and delayed culture conversion (⩾70 days) were at 'high risk of relapse', and anti-tuberculosis treatment of ⩾270 days was 'extended treatment'. We used a generalized linear model to identify independent risk factors for absence of extended treatment in the high risk of relapse group.

RESULTS

Among 5680 TB patients, 483 (8.5%) were at high risk of relapse: 372 (77%) received extended treatment but 111 (23%) did not. Factors associated with absence of extended treatment included negative sputum smears (adjusted prevalence ratio [aPR] 2.62, 95%CI 1.69-4.05), residence in three specific counties (aPR 1.71, 95%CI 1.19-2.46) and Black race (aPR 1.56, 95%CI 1.03-2.38).

CONCLUSIONS

Nearly a quarter of TB patients at high risk of relapse did not receive extended treatment. Increased efforts are needed to ensure that all patients who may benefit from extended anti-tuberculosis treatment receive it.

Identification of the novel HLA-DRB1*12:50 allele by polymerase chain reaction sequence-based typing in a Chinese individual

HLA-DRB1*12:50 is different from HLA-DRB1*12:02:01 by a single nucleotide substitution at position 320 A>C.

[Impact of long-term continuous positive airway pressure treatment for patients with obstructive sleep apnea syndrome]

OBJECTIVE

To investigate the long-term efficacy of continuous positive airway pressure (CPAP) treatment for patients with obstructive sleep apnea syndrome (OSAS).

METHODS

This case control study was performed among 154 patients with moderate or severe OSAS between September 2009 and September 2014. Patients were divided into treatment group (n=66, 53 patients with hypertension) and control group (n=88, 67 patients with hypertension). The long-term efficacy of CPAP treatment on clinical events and blood pressure was evaluated.

RESULTS

The combined incidence of death, myocardial infarction, coronary revascularization and stroke events was 1.5% (1/66) in treatment group and 11.4% (10/88) in control group (P<0.05). CPAP treatment also led to more significant reduction in systolic blood pressure ((12.24±18.06) mmHg(1 mmHg=0.133 kPa) to (4.24±16.63) mmHg, P<0.05) in the patients with hypertension in these two groups.

CONCLUSIONS

CPAP treatment could reduce the risk of cardiovascular and neurovascular events for patients with moderate or severe OSAS.

Prognostic significance of DLL4 expression in papillary thyroid cancer

OBJECTIVE

Delta-like ligand 4 (DLL4)-Notch signaling has an important role in tumor neovascular development and angiogenesis during tumor growth. However, the clinical significance of DLL4 expression in papillary thyroid cancer remains unclear to date.

PATIENTS AND METHODS

207 papillary thyroid cancer patients were in the present study. DLL4 expression in papillary thyroid cancer was analyzed and evaluated immunohistochemically. The correlation between DLL4 and clinicopathological factors was also evaluated.

RESULTS

DLL4 expression was showed in the cytoplasm of papillary thyroid cancer cells by immunohistochemical staining. DLL4 positivity in papillary thyroid cancer was found in 112 (54%) of the 207 papillary thyroid cancer patients. Papillary thyroid cancer DLL4 expression was significantly correlated with thyroid tumour invasion and metastasis.

CONCLUSIONS

Overexpression of DLL4 is associated with thyroid tumour invasion and metastasis and it may be an effective target of anti-DLL4 treatment in papillary thyroid cancer.

HLA-A, HLA-B, HLA-DRB1 allele and haplotype frequencies in 6384 umbilical cord blood units and transplantation matching and engraftment statistics in the Zhejiang cord blood bank of China

Umbilical cord blood (UCB) is a widely accepted source of progenitor cells, and now, many cord blood banks were established. Here, we analysed the HLA-A, HLA-B and HLA-DRB1 allele and haplotype frequencies, HLA matching possibilities for searching potential donors and outcome of UCB transplantations in Zhejiang cord blood bank of China. A total of 6384 UCB units were characterized for 17 HLA-A, 30 HLA-B and 13 HLA-DRB1 alleles at the first field resolution level. Additionally, B*14, B*15 and B*40 were typed to the second field level. A total of 1372 distinct A-B-DRB1 haplotypes were identified. The frequencies of 7 haplotypes were more than 1%, and 439 haplotypes were <0.01%. A*02-B*46-DRB1*09, A*33-B*58-DRB1*03 and A*30-B*13-DRB1*07 were the most common haplotypes, with frequencies of 4.4%, 3.3%, and 2.9%, respectively. Linkage disequilibrium(LD) analysis showed that there were 83 A-B, 106 B-DRB1, 54 A-DRB1 haplotypes with positive LD, in which 51 A-B, 60 B-DRB1, 32 A-DRB1 haplotypes exhibited a significant LD (P < 0.05). In 682 search requests, 12.9%, 40.0% and 42.7% of patients were found to have 6 of 6, 5 of 6 and 4 of 6 HLA-A, HLA-B and HLA-DRB1 matching donors, respectively. A total of 30 UCB units were transplanted to 24 patients (3 patients not evaluated due to early death); 14 of 21 patients (66.7%) engrafted. This study reveals the HLA distribution and its transplantation application in the cord blood bank of Zhejiang province. These data can help to select potential UCB donors for transplantation and used to assess the scale of new cord blood banking endeavours.

Primary carnitine deficiency and sudden death: in vivo evidence of myocardial lipid peroxidation and sulfonylation of sarcoendoplasmic reticulum calcium ATPase 2

OBJECTIVES

Primary carnitine deficiency is an autosomal recessive disorder caused by mutations in the SLC22A5 gene which results in impaired carnitine transport, cytosolic fatty acid accumulation and impaired beta oxidation. The disease is associated with cardiomyopathy and arrhythmias, but the mechanism is unknown. We hypothesized that carnitine deficiency results in increased myocardial oxidative stress.

METHODS

We evaluated a 22-year-old woman with primary carnitine deficiency and ventricular fibrillation, as well as her first-degree relatives.

RESULTS

Sequencing of SLC22A5 identified two deleterious mutations (A142S and R488H) and a novel mutation predicted to be a splice variant. Histology demonstrated increased myocardial lipid deposition and swollen mitochondria. Immunohistochemistry demonstrated accumulation of the reactive aldehyde 4-hydroxy-2-nonenal, indicative of increased lipid peroxidation, and sulfonylation of sarcoendoplasmic reticulum calcium ATPase 2 at cysteine 674.

CONCLUSIONS

These findings suggest that increased oxidant stress may contribute to myocardial dysfunction and arrhythmogenesis in this disorder.

Chinese medicinal formula Guan-Xin-Er-Hao protects the heart against oxidative stress induced by acute ischemic myocardial injury in rats

Guan-Xin-Er-Hao (GXEH) is a Chinese medicine formula for treating ischemic heart diseases (IHD) and has a favorable effect. Our aim was to examine whether or not acute oral GXEH could protect the heart against myocardial infarction and apoptosis in acute myocardial ischemic rats. If so, we would explain the antioxidative mechanism involved. The left anterior descending coronary artery was occluded to induce myocardial ischemia in hearts of Sprague-Dawley rats. At the end of the 3h ischemic period (or 24h for infarct size), we measured the myocardial infarct size, myocardial apoptosis and the activities of antioxidative enzymes. GXEH reduced infarct size, myocardial apoptosis and the serum level of malondialdehyde (MDA), increased the activities of total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and GSH-peroxidase (GPX) activities and the serum level of glutathione (GSH). GXEH exerts significant cardioprotective effects against acute ischemic myocardial injury in rats, likely through its antioxidation and antilipid peroxidative properties, and thus may be used as a promising agent for both prophylaxis and treatment of IHD.

Immune modulation by melanoma and ovarian tumor cells through expression of the immunosuppressive molecule CD200

BACKGROUND AND OBJECTIVE

Immune escape by tumors can occur by multiple mechanisms, each a significant barrier to immunotherapy. We previously demonstrated that upregulation of the immunosuppressive molecule CD200 on chronic lymphocytic leukemia cells inhibits Th1 cytokine production required for an effective cytotoxic T cell response. CD200 expression on human tumor cells in animal models prevents human lymphocytes from rejecting the tumor; treatment with an antagonistic anti-CD200 antibody restored lymphocyte-mediated tumor growth inhibition. The current study evaluated CD200 expression on solid cancers, and its effect on immune response in vitro.

METHODS AND RESULTS

CD200 protein was expressed on the surface of 5/8 ovarian cancer, 2/4 melanoma, 2/2 neuroblastoma and 2/3 renal carcinoma cell lines tested, but CD200 was absent on prostate, lung, breast, astrocytoma, or glioblastoma cell lines. Evaluation of patient samples by immunohistochemistry showed strong, membrane-associated CD200 staining on malignant cells of melanoma (4/4), ovarian cancer (3/3) and clear cell renal cell carcinoma (ccRCC) (2/3), but also on normal ovary and kidney. CD200 expression on melanoma metastases was determined by RT-QPCR, and was found to be significantly higher in jejunum metastases (2/2) and lung metastases (2/6) than in normal samples. Addition of CD200-expressing, but not CD200-negative solid tumor cell lines to mixed lymphocyte reactions downregulated the production of Th1 cytokines. Inclusion of antagonistic anti-CD200 antibody restored Th1 cytokine responses.

CONCLUSION

These data suggest that melanoma, ccRCC and ovarian tumor cells can express CD200, thereby potentially suppressing anti-tumor immune responses. CD200 blockade with an antagonistic antibody may permit an effective anti-tumor immune response in these solid tumor types.

Regulation of TRP ion channels by phosphatidylinositol-4,5-bisphosphate

Phosphatidylinositol-4,5-bisphosphate (PIP2) has emerged as a versatile regulator of TRP ion channels. In many cases, the regulation involves interactions of channel proteins with the lipid itself independent of its hydrolysis products. The functions of the regulation mediated by such interactions are diverse. Some TRP channels absolutely require PIP2 for functioning, while others are inhibited. A change of gating is common to all, endowing the lipid a role for modulation of the sensitivity of the channels to their physiological stimuli. The activation of TRP channels may also influence cellular PIP2 levels via the influx of Ca2+ through these channels. Depletion of PIP2 in the plasma membrane occurs upon activation of TRPV1, TRPM8, and possibly TRPM4/5 in heterologous expression systems, whereas resynthesis of PIP2 requires Ca2+ entry through the TRP/TRPL channels in Drosophila photoreceptors. These developments concerning PIP2 regulation of TRP channels reinforce the significance of the PLC signaling cascade in TRP channel function, and provide further perspectives for understanding the physiological roles of these ubiquitous and often enigmatic channels.

Immune evasion by CD200: New approaches to targeted therapies for chronic lymphocytic leukemia (CLL)

2519

Background: Although the human immune system is capable of raising an immune response against many cancer types, that response is insufficient to eradicate the cancer in most patients, possibly due to immune evasion through negative regulation of the immune system by the tumor. We identified the immune-suppressive molecule CD200 to be upregulated 1.5–5.4-fold on CLL cells in all 80 patients examined. Interaction of CD200 with its receptor alters cytokine profiles from Th1 to Th2 in mixed lymphocyte reactions, and results in the induction of regulatory T cells, which are thought to hamper tumor-specific effector T cell immunity. We addressed whether CD200 expression on tumor cells plays a role in immune evasion, thereby preventing elimination of tumor cells by the immune system in a xenograft hu/SCID mouse model, and whether treatment with an antagonistic anti-CD200 antibody affects tumor growth. Methods: The human non-Hodgkins lymphoma cell lines RAJI and Namalwa were transduced with human CD200 and injected subcutaneously together with human peripheral blood lymphocytes (PBL) into NOD/SCID mice. Tumor growth over time was compared among mice that either received CD200-expressing tumor cells or received tumor cells lacking CD200 expression. In subsequent experiments, mice were treated with chimeric or humanized anti-CD200 antibodies (doses ranged from 1 to 20 mg/kg) by intravenous injection. Treatment was either started immediately or 7 days after tumor cell injection. Results: As expected, PBLs reduced CD200-negative RAJI or Namalwa tumor growth by up to 75%. In contrast, growth of RAJI or Namalwa tumors expressing CD200 at levels comparable to that of CLL was not reduced by PBLs. Administration of anti-CD200 antibodies at 5 mg/kg resulted in nearly complete tumor growth inhibition (1/10 mice developed a small tumor) over the course of the study even when treatment was started 7 days after tumor cell injection. Conclusions: CD200 expression on tumor cells inhibits the ability of human lymphocytes to eradicate tumor cells. Treatment of CD200-expressing tumors with antagonistic anti-CD200 antibodies inhibits tumor growth, indicating the potential for anti-CD200 therapy as a promising approach for CLL.

No significant financial relationships to disclose.

Immune evasion by melanoma and ovarian tumor cells through upregulation of the immunosuppressive molecule CD200

2545

Background: Immune escape by tumors can occur by multiple mechanisms, each a significant barrier to immunotherapy. Upregulation of the immunosuppressive molecule CD200 on chronic lymphocytic leukemia cells inhibits Th1 cytokine production required for an effective cytotoxic T cell response. CD200 expression on human tumor cells in animal models prevents human lymphocytes from rejecting the tumor; treatment with an antagonistic anti-CD200 antibody restored lymphocyte-mediated tumor growth inhibition. This study evaluated CD200 expression on other cancers, and its effect on immune response. Methods: CD200 levels in ovarian adenocarcinoma and metastatic melanoma samples were evaluated by RT-QPCR and immunohistochemistry. Cell-surface CD200 on melanoma and ovarian cancer cell lines was assessed by flow cytometry. The effect of CD200 on cytokine production in mixed lymphocyte reactions (MLR) was assessed by adding the cells to cultures containing human monocyte-derived dendritic cells and allogeneic T cells. Th1 and Th2 cytokines in culture supernatants were detected by ELISA. Results: RT-QPCR showed CD200 expression levels upregulated in serous ovarian adenocarcinoma compared to normal samples. In malignant melanoma, CD200 expression in jejunum metastases was significantly higher than in normal samples, and 2 of 6 lung metastases showed CD200 upregulation. IHC showed strong, membrane-associated CD200 staining on malignant cells of two melanoma patients. Three ovarian cancer patients showed varying levels of CD200 tumor staining; all showed strong stromal staining. CD200 was highly expressed on the cell surface of SK-MEL-24 and SK-MEL-28 melanoma and OV-CAR-3 ovarian cancer cell lines and moderately expressed on the melanoma cell line SK-MEL-5. Addition of these cell lines to MLRs downregulated the production of Th1 cytokines; addition of CD200-negative cell lines did not. Inclusion of an antagonistic anti-CD200 antibody during the culture restored Th1 cytokine responses. Conclusion: Melanoma and ovarian tumor cells can upregulate CD200, thereby potentially suppressing anti-tumor immune responses. Therapy with an antagonistic anti-CD200 antibody may permit an effective cytotoxic immune response against the tumor cells.

[Table: see text]

[Effects of dopexamine on cardiac hemodynamics during myocardial ischemia in rats and in comparison with fenoldopam and procaterol]

The effect of dopexamine hydrochloride(DPX) on cardiac hemodynamics during acute myocardial ischemia (AMI) was studied in rats and compared with those of fenoldopam hydrochloride(FODA) and procaterol hydrochloride (PCT). The results showed that i.v. DPX remarkably attenuated the increases of total peripheral resistance(TPR) and left ventricular end-diastolic pressure and the decreases of + dp/dt max caused by ischemia, while DPX showed no significant effect on mean arterial pressure(MAP). Although FODA was more potent than DPX in attenuating the increase of TPR and the decrease of myocardial contractility caused by ischemia, it significantly decreased MAP. The effects of PCT on all these variables were the smallest among the 3 agents. The results suggest that DPX has a better prospect in the treatment of ischemic heart disease in view of its actions of decreasing TPR, mild increase of myocardial contractility, without MAP decrease and myocardial oxygen consumption increase.

Antioxidant vitamins attenuate oxidative stress and cardiac dysfunction in tachycardia-induced cardiomyopathy

OBJECTIVES

We administered antioxidant vitamins to rabbits with pacing-induced cardiomyopathy to assess whether antioxidant therapy retards the progression of congestive heart failure (CHF).

BACKGROUND

Although oxidative stress is increased in CHF, whether progression of heart failure could be prevented or reduced by antioxidants is not known.

METHODS

Rabbits with chronic cardiac pacing and sham operation were randomized to receive a combination of beta-carotene, ascorbic acid and alpha-tocopherol, alpha-tocopherol alone or placebo over eight weeks. Echocardiography was used to measure cardiac function weekly. Resting hemodynamics and in vivo myocardial beta-adrenergic responsiveness were studied at week 8. Animals were then sacrificed for measuring myocardial beta-receptor density, norepinephrine (NE) uptake-1 site density, sympathetic neuronal marker profiles, tissue-reduced glutathione/oxidized glutathione (GSH/GSSG) ratio and oxidative damage of mitochondrial DNA (mtDNA).

RESULTS

Rapid cardiac pacing increased myocardial oxidative stress as evidenced by reduced myocardial GSH/GSSG ratio and increased oxidized mtDNA and produced cardiac dysfunction, beta-adrenergic subsensitivity, beta-receptor downregulation, diminished sympathetic neurotransmitter profiles and reduced NE uptake-1 carrier density. A combination of antioxidant vitamins reduced the myocardial oxidative stress, attenuated cardiac dysfunction and prevented myocardial beta-receptor downregulation and sympathetic nerve terminal dysfunction. Administration of alpha-tocopherol alone produced similar effects, but the effects were less marked than those produced by the three vitamins together. Vitamins produced no effects in sham-operated animals.

CONCLUSIONS

Antioxidant vitamins reduced tissue oxidative stress in CHF and attenuated the associated cardiac dysfunction, beta-receptor downregulation and sympathetic nerve terminal abnormalities. The findings suggest that antioxidant therapy may be efficacious in human CHF.

Remodeling and suppression of intimal hyperplasia of vascular grafts with a distal arteriovenous fistula in a rat model

PURPOSE

The purpose of this study was to evaluate the effects of a distal arteriovenous fistula (dAVF) on the morphologic changes occurring in arterial bypass grafts by the use of a novel experimental model.

METHODS

Aortofemoral bypass grafts with or without dAVFs were constructed in 36 Sprague-Dawley rats with a microsurgical technique. The bypass graft material consisted of deendothelialized autogenous tail artery (length, 25 mm; inside diameter, 0.5 mm). In 18 rats, dAVFs were constructed at the distal anastomosis. After 6 weeks, flow rates and shear stress were determined, and grafts were then harvested. Luminal, intimal, and medial cross-sectional areas were measured with computer imaging. Desmin, alpha-smooth muscle actin, and von Willebrand factor (vWF) were identified with immunohistochemistry. Endothelialization was evaluated with SEM.

RESULTS

All bypass grafts remained patent at the time of graft harvest. Grafts with dAVFs showed increased flow rates (11.5 +/- 0.6 mL/min) compared with grafts without dAVFs (2.1 +/- 0.3 mL/min; P < .01). Shear stress was also increased in the dAVF group (340.9 +/- 23.4 dyne/cm(2) vs 113.7 +/- 12.5 dyne/cm(2); P < .01), with a corresponding suppression of intimal hyperplasia (0.059 +/- 0.011 mm(2) for dAVF grafts vs 0.225 +/- 0.009 mm(2) for non-dAVF grafts; P < .01). Staining for vWF was found in both the reendothelialized flow surface and the neointimal extracellular matrix. Remodeling of the grafts was characterized by a 50% increased luminal area, 70% decreased intimal area, and a 25% decreased medial area when a dAVF was constructed.

CONCLUSION

A small animal experimental model of an arterial bypass graft can enable the evaluation of a variety of factors that influence graft patency. Increased blood flow velocity and shear stress induced by a dAVF are associated with a decrease in intimal and medial areas, which may reflect changes in cell proliferation, apoptosis, migration, or matrix deposition. Deposition of vWF was also found both in the endothelium and throughout the hyperplastic intima. These findings suggest that the hemodynamic and morphologic changes associated with dAVF may potentiate graft patency and function.

Antioxidant vitamins prevent cardiomyocyte apoptosis produced by norepinephrine infusion in ferrets

BACKGROUND

Norepinephrine (NE) induces apoptosis in cultured neonatal rat myocytes. To determine whether this change occurred in intact animals after chronic subhypertensive doses of NE, and whether the effect was mediated via oxidative stress produced by NE, we measured myocyte apoptosis and apoptotic gene proteins in ferrets receiving chronic NE with and without antioxidant vitamin treatment.

METHODS

Ferrets were administered either subcutaneous NE or vehicle and simultaneously assigned to receive antioxidant vitamins (beta-carotene, ascorbic acid and alpha-tocopherol) or vehicle for 4 weeks. Resting hemodynamics and plasma NE were measured at 4 weeks. Animals were then sacrificed for measuring cardiac myocyte size by electron microscopy, and oxidative stress by reduced to oxidized glutathione (GSH/GSSG) ratio and mitochrondrial DNA 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG). Cardiomyocyte apoptosis was detected by both terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and monoclonal antibody to single-stranded DNA (Mab) staining. Western blot analysis was used to measure the expression of the antiapoptotic protein Bcl-2 and apoptotic protein Bax.

RESULTS

NE administration produced a 4-fold increase in plasma NE, but had no effect on resting heart rate, heart weight, arterial pressure, left ventricular systolic function or cardiac cell size. NE infusion decreased tissue GSH/GSSG ratio, and increased mtDNA 8-oxo-dG, and TUNEL- and Mab-positive apoptotic cells. These changes were associated with a 27% decrease in Bcl-2 protein, a 42% increase in Bax and a 57% reduction in the ratio of Bcl-2/Bax. All of the changes were prevented by co-administration of antioxidant vitamins.

CONCLUSION

NE administration at a dose which produced no significant increase in blood pressure or myocyte hypertrophy caused cardiomyocyte apoptosis in intact animals. This effect was associated with an increase in oxidative stress, up-regulation of Bax protein and down-regulation of Bcl-2 protein. Antioxidant vitamins prevented the changes produced by NE. The findings suggest that NE-induced myocyte apoptosis is mediated by oxidative stress, and that antioxidant vitamins may be beneficial in heart failure in which cardiac NE release is increased.

Glucose-dependent insulinotropic peptide is an integrative hormone with osteotropic effects

Glucose-dependent insulinotropic peptide (GIP) is a gut-derived hormone known to be important in modulating glucose-induced insulin secretion. In addition, GIP receptors are widely distributed and may have effects on multiple other tissues: fat cells, adrenal glands, endothelium and brain. We have demonstrated recently that GIP also has anabolic effects on bone-derived cells. We now demonstrate that GIP administration prevents the bone loss associated with ovariectomy. We propose that GIP plays a unique role in signaling the bone about nutrient availability, indicating the importance of the gut hormones in directing absorbed nutrients to the bone, and suggesting the concept of an 'entero-osseous axis'. Thus, GIP plays an integrative role helping coordinate efficient and targeted nutrient absorption and distribution.

A high-resolution radiation hybrid map of the human genome draft sequence

We have constructed a physical map of the human genome by using a panel of 90 whole-genome radiation hybrids (the TNG panel) in conjunction with 40,322 sequence-tagged sites (STSs) derived from random genomic sequences as well as expressed sequences. Of 36,678 STSs on the TNG radiation hybrid map, only 3604 (9.8%) were absent from the unassembled draft sequence of the human genome. Of 20,030 STSs ordered on the TNG map as well as the assembled human genome draft sequence and the Celera assembled human genome sequence, 36% of the STSs had a discrepant order between the working draft sequence and the Celera sequence. The TNG map order was identical to one of the two sequence orders in 60% of these discrepant cases.

[The protective effects of Zn-metallothionein on severely scalded rats inflicted by oxygen free radicals]

OBJECTIVE

To investigate the protective effects of metallothionein (MT) on severely scalded rats inflicted by oxygen free radicals after delayed resuscitation.

METHODS

Wistar rats inflicted by 30% TBSA III degree scalding injury were taken as the model. Fifty-Six rats were randomly divided into four groups, i.e. normal control, delayed resuscitation, MT treated and VitC treated groups. The changes in superoxide dismutase (SOD) and malondialdehyde (MDA) contents in plasma and subeschar edematous fluid were determined at 24 and 48 postburn hours with traditional indirect detecting method and electron spin resonance (ESR). Pathomorphological examination was simultaneously carried out for cardiac, hepatic, renal and intestinal samples. Plasma biochemical indices were determined at the same time.

RESULTS

In delayed resuscitation group, SOD content decreased and the MDA contents increased in plasma and subeschar fluid obviously, with remarkable changes in the pathomorphology of all the internal organs and the blood biochemical indices. But in MT treating group, SOD content increased (P < 0.05) with decreased content of MDA (P < 0.05) and the pathomorphology and blood biochemical indices improved significantly when compared with those in delayed resuscitation group and VitC treatment group.

CONCLUSION

MT treatment might be beneficial in the management of severely scalding rats infliced by oxygen free radicals.

Rapid upregulation of caspase-3 in rat spinal cord after injury: mRNA, protein, and cellular localization correlates with apoptotic cell death

Although the precise mechanisms explaining loss of, and failure to regain, function after spinal cord injury are unknown, there is increasing interest in the role of "secondary cell death." One prevalent theme in cell loss in other regions of the CNS involves apoptosis executed by the intracellular caspase proteases. A recent study demonstrated that spinal cord injury rapidly increased the activation of caspase-3. Our previous studies demonstrated peak apoptosis in three of four cellular compartments 3 days after controlled contusion in the rat. We have extended these analyses to include enzyme and substrate studies of caspase subfamilies both in rostral and in caudal adjacent segments compared to the lesion site. Although presumed activation of programmed proenzyme is considered the mechanism for enhanced caspases, our novel analyses were designed to detect upregulation of gene expression. We surveyed traumatically injured spinal cord for caspase family messages with a modified differential mRNA display approach and found that the caspase-3 (CASP3) message was present and upregulated severalfold after injury. Our results clearly demonstrate that cell death in the spinal cord occurs after posttranslational activation of caspases that follow, at least for caspase-3, initial upregulation of CASP3 mRNA levels.

Regulation of the dual function tissue transglutaminase/Galpha(h) during murine neuromuscular development: gene and enzyme isoform expression

Coagulation Factor XIII (F. VIII), a member of the transglutaminase (TGase) superfamily, is activated by thrombin, cross-links fibrin and stabilizes clots. Another member of this family, tissue TGase (tTG), having similar enzymatic activity, is implicated in neural development and synapse stabilization. Our previous studies indicated that synapse formation and maintenance at the neuromuscular junction (NMJ) involved components of the coagulation cascade in development. Others then showed that either F. XIII or tTG were localized at NMJs in a developmentally-regulated fashion. In the current studies, we addressed the temporal course of skeletal muscle tTG gene expression and found maximal expression at birth and continuing into the immediate postnatal period. Subcellular fractionation revealed a relatively constant particulate isoform of TGase activity which predominated in early embryonic muscle development. In contrast, cytosolic TGase specific activity became the major isoform in the postnatal period. The timing of muscle TGase activity correlated well with expression of tTG mRNA and we now present novel data of Tgm 2 gene expression for tTG in skeletal muscle. Confirming and extending the previous studies, TGase becomes localized at NMJs in the early, further ramifying in the late, neonatal period. These data suggest that the early pulse of particulate activity could coincide with the period of myoblast cell death in embryonic muscle. On the other hand, the peak cytosolic TGase activity occurs in the neonatal period, correlating temporally with muscle prothrombin expression during activity-dependent synapse elimination and possibly the source of the enzyme localized to the NMJ extracellular matrix resulting in synaptic stabilization.

Hidden Markov modeling for single channel kinetics with filtering and correlated noise

Hidden Markov modeling (HMM) can be applied to extract single channel kinetics at signal-to-noise ratios that are too low for conventional analysis. There are two general HMM approaches: traditional Baum's reestimation and direct optimization. The optimization approach has the advantage that it optimizes the rate constants directly. This allows setting constraints on the rate constants, fitting multiple data sets across different experimental conditions, and handling nonstationary channels where the starting probability of the channel depends on the unknown kinetics. We present here an extension of this approach that addresses the additional issues of low-pass filtering and correlated noise. The filtering is modeled using a finite impulse response (FIR) filter applied to the underlying signal, and the noise correlation is accounted for using an autoregressive (AR) process. In addition to correlated background noise, the algorithm allows for excess open channel noise that can be white or correlated. To maximize the efficiency of the algorithm, we derive the analytical derivatives of the likelihood function with respect to all unknown model parameters. The search of the likelihood space is performed using a variable metric method. Extension of the algorithm to data containing multiple channels is described. Examples are presented that demonstrate the applicability and effectiveness of the algorithm. Practical issues such as the selection of appropriate noise AR orders are also discussed through examples.

A direct optimization approach to hidden Markov modeling for single channel kinetics

Hidden Markov modeling (HMM) provides an effective approach for modeling single channel kinetics. Standard HMM is based on Baum's reestimation. As applied to single channel currents, the algorithm has the inability to optimize the rate constants directly. We present here an alternative approach by considering the problem as a general optimization problem. The quasi-Newton method is used for searching the likelihood surface. The analytical derivatives of the likelihood function are derived, thereby maximizing the efficiency of the optimization. Because the rate constants are optimized directly, the approach has advantages such as the allowance for model constraints and the ability to simultaneously fit multiple data sets obtained at different experimental conditions. Numerical examples are presented to illustrate the performance of the algorithm. Comparisons with Baum's reestimation suggest that the approach has a superior convergence speed when the likelihood surface is poorly defined due to, for example, a low signal-to-noise ratio or the aggregation of multiple states having identical conductances.

Alterations by norepinephrine of cardiac sympathetic nerve terminal function and myocardial beta-adrenergic receptor sensitivity in the ferret: normalization by antioxidant vitamins

BACKGROUND

Chronic excessive norepinephrine (NE) causes cardiac sympathetic nerve terminal abnormalities, myocardial beta-adrenergic receptor downregulation, and beta-adrenergic subsensitivity. The present study was carried out to determine whether these changes could be prevented by antioxidants.

METHODS AND RESULTS

Ferrets were administered either NE (1.33 mg/d) or vehicle by use of subcutaneous pellets for 4 weeks. Animals were simultaneously assigned to receive either antioxidant vitamins (beta-carotene, ascorbic acid, and alpha-tocopherol) or placebo pellets. NE increased plasma NE 4- to 5-fold but had no effect on heart rate, heart weight, arterial pressure, or left ventricular systolic function. However, myocardial NE uptake activity and NE uptake-1 site density were reduced, as well as cardiac neuronal NE, tyrosine hydroxylase, and neuropeptide Y. In addition, there was a decrease in myocardial beta-adrenergic receptor density with a selective decrease of the beta(1)-receptor subtype, reduction of the high-affinity site for isoproterenol, decreased basal adenylyl cyclase activity, and the adenylyl cyclase responses to isoproterenol, Gpp(NH)p, and forskolin. All of these changes were prevented by antioxidant vitamins. The effects of NE on myocardial beta-adrenergic receptor density, NE uptake-1 carrier site density, and neuronal NE were also prevented by superoxide dismutase or Trolox C.

CONCLUSIONS

The toxic effects of NE on the sympathetic nerve terminals are mediated via the formation of NE-derived oxygen free radicals. Preservation of the neuronal NE reuptake mechanism is functionally important, because the antioxidants also prevented myocardial beta-adrenergic receptor downregulation and postreceptor abnormalities. Thus, antioxidant therapy may be beneficial in heart failure, in which cardiac NE release is increased.

The tourniquet revisited as an adjunct to lower limb revascularization

PURPOSE

The purpose of this study was to evaluate the role and efficacy of the tourniquet in lower limb revascularization.

METHODS

During a 3-year period, 195 patients underwent 205 infrainguinal reconstruction operations in the lower extremity. These patients underwent bypass with a tourniquet and inflow occlusion (group 1) or bypass without a tourniquet (group 2). The type of infrainguinal reconstruction, tourniquet ischemia time, blood loss, and complications related to tourniquet use were recorded. A subset of patients underwent serial muscle biopsies. Specimens from calf muscle were taken just (1) before application of the tourniquet, (2) before tourniquet release, and (3) once wound closure was initiated. These biopsy specimens were studied by histochemical staining and also analyzed for phosphorylase enzyme, a marker for subcellular ischemia.

RESULTS

One hundred eleven patients underwent 117 infrainguinal reconstruction procedures in which the tourniquet and inflow occlusion were used. These patients were matched against 84 patients who underwent 88 infrainguinal reconstructions without the use of the tourniquet. Complete hemostatic control in group 1 was obtained in 108 of the procedures (92%). Eight percent of the procedures required minor additional techniques to obtain complete hemostasis; in two instances, the tourniquet was removed because it did not provide hemostasis. Mean tourniquet time was less than 1 hour for all reconstruction groups. There were no instances of neurologic deficit, thrombosis of distal vessels, or vascular injury that was related to the use of a tourniquet. A comparison of the two groups revealed no differences with regard to overall blood loss (P =.63) or duration of operation (P = 0.60), observations that reflect the complexity of the cases rather than the use or nonuse of a tourniquet. When tourniquet control was used, we noted a definite decrease in the time for the distal dissection, because total vascular control with extensive dissection was unnecessary. Histochemical analysis with phosphorylase revealed a conversion of tissue with active enzyme activity to a low level with tourniquet use (P <.05).

CONCLUSION

The use of a tourniquet for lower limb revascularization is safe and effective and improves visualization of the operative field. Less dissection of the target vessels is required. With a combination of the nonuse of clamps and other occluding devices, we project a decrease in host hyperplastic response that will, in turn, impact favorably on patency rates. The possibility exists that early failure may be prevented by avoiding the application of traumatic forces to diseased and brittle or calcified arteries. In this study, tourniquet time had no impact on overall operative procedural time, although certain phases of the operation were clearly shortened and facilitated, particularly in complex and difficult reconstructions. Histochemical changes found in muscle biopsy specimens did not adversely impact patients clinically, but further investigation is required to elucidate subcellular events.

Osteoblast-derived cells express functional glucose-dependent insulinotropic peptide receptors

Glucose-dependent insulinotropic peptide (GIP) is a 42-amino acid peptide synthesized and secreted from endocrine cells in the small intestine. The role of GIP in coupling nutrient intake and insulin secretion, the incretin effect, is well known. We report that GIP receptor messenger RNA and protein are present in normal bone and osteoblast-like cell lines, and that high affinity receptors for GIP can be demonstrated by [125I]GIP binding studies. When applied to osteoblast-like cells (SaOS2), GIP stimulated increases in cellular cAMP content and intracellular calcium, with both responses being dose dependent. Moreover, administration of GIP results in elevated expression of collagen type I messenger RNA as well as an increase in alkaline phosphatase activity. Both of these effects reflect anabolic actions of presumptive osteoblasts. These results provide the first evidence that GIP receptors are present in bone and osteoblast-like cells and that GIP modulates the function of these cells.

[Changes of serum elastase, alpha 1-antitrypsin, procollagen III peptide and malonaldehyde in smokers with and without chronic obstructive pulmonary diseases]

OBJECTIVE

Serum elastase, alpha(1)-antitrypsin (alpha(1)-AT), procollagen III peptide (PIIIP) and malonaldehyde (MDA) were studied in smokers with and without chronic obstructive pulmonary disease (COPD) to explore the roles of these factors in COPD induced by smoking.

METHODS

A design of 154-pair case-control study was used. alpha(1)-AT, MDA and PIIIP were determined with colorimetric method, fluo-spectrophotometric method and radio-immunological assay, respectively, in non-smoker control and smokers with and without COPD.

RESULTS

Serum PIIIP content was increased in smokers and alpha(1)-AT decreased significantly in patients with COPD.

CONCLUSION

Decreased alpha(1)-AT may be a susceptible factor in the development of COPD caused by smoking.

[Effects of metallothionein (MT) on burned skin of rats]

OBJECTIVE

To elucidate the relationship between skin viability and lipid peroxidation after deep partial thickness burn injury.

METHODS

Deep partial thickness burn was produced. Metallothionin (MT) in different concentrations (0.5 x 10(-6) mol/L, 1 x 10(-5) mol/L) was topically applied. Oxygen consumption, succinate dehydrogenase(SDH), Schiff's base contents and healing time of wound were determined in 24 Wistar rats. Specimens were harvested at 8, 24, and 48-hour postburn.

RESULTS

Oxygen consumption and SDH value decreased and Schiff's base value increased after burn injury. With the application of MT, oxygen consumption and SDH value of burned skin were significantly higher compared with control group, and Schiff's base value was significantly lower (P < 0.05 or P < 0.01). The mean healing time of burned wound was two days less in two MT protection groups.

CONCLUSION

MT may be beneficial in improving postburn skin viability by attenuating lipid peroxidation of burned tissue.

1,25-dihydroxyvitamin D3 induces phospholipase D-1 expression in primary mouse epidermal keratinocytes

The hormone 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) elicits the programmed pattern of differentiation in epidermal keratinocytes. Based on data indicating a potential role of phospholipase D (PLD) in mediating keratinocyte differentiation, we investigated the effect of 1,25(OH)2D3 on PLD expression. A 24-h exposure to 1, 25(OH)2D3 stimulated PLD-1, but not PLD-2, mRNA expression. This 1, 25(OH)2D3-enhanced expression was accompanied by increased total PLD and PLD-1 activity. Time course studies indicated that 1,25(OH)2D3 induced PLD-1 expression by 8 h, with a maximal increase at 20-24 h. Exposure to 1,25(OH)2D3 inhibited proliferation over the same time period with similar kinetics. Expression of the early (spinous) differentiation marker keratin 1 decreased in response to 1, 25(OH)2D3 over 12-24 h. Treatment with 1,25(OH)2D3 enhanced the activity of transglutaminase, a late (granular) differentiation marker, by 12 h with a maximal increase after 24 h. In situ hybridization studies demonstrated that the highest levels of PLD-1 expression are in the more differentiated (spinous and granular) layers of the epidermis, with little expression in basal keratinocytes. Our results suggest a role for PLD expression/activity during keratinocyte differentiation.

[Effect of the IL-6 transfected bone marrow stromal cells on the recovery of hematopoietic functions in bone marrow transplanted mice]

OBJECTIVE

To study the effect of the IL-6 transfected bone marrow stromal cell, QXMSC1 IL-6, on the hematopoietic reconstitution in bone marrow transplanted mice.

METHODS

Bone marrow transplantation model was established by infusing hematopoietic cells combined with QXMSC1 IL-6 into syngeneic recipient mice through the tail vein. CFU-S, CFU-GM, CFU-E, BFU-E, and peripheral blood pictures were assayed.

RESULTS

QXMSC1 IL-6 could increase the CFU-S, CFU-GM, CFU-E and BFU-E yields in BMT mice, and accelerate the recovery of peripheral blood cells.

CONCLUSION

QXMSC1 IL-6 can improve the hematopoietic reconstitution in bone marrow transplanted mice.

[Reconstruction with silicone rubber tube after resection of hypopharyngeal and cervical esophageal cancer]

OBJECTIVE

To treat the benign stenosis and defects caused by resection of cancers of hypopharyngeal and cervical esophagus.

METHODS

Silicone rubber tubes made by ourselves were utilized to reconstruct the defect. It was found that in animal models, the granulation surface was covered with epithelial tissues and new lumen formed.

RESULTS

Among 30 cases treated with silicone rubber tubes, 6 cases (20.0%) developed hypopharyngeal fistulae after operations. Twenty-five cases with cancer and 5 cases with benign stenoses and hypopharyngeal fistulae were followed-up from 5 months to 4 years. The silicone rubber tubes in 25 cases were decannulated, of them, 23 cases recovered normal swallowing function. Two cases developed severe stenosis again and 2 cases were under observation. In 25 cases with cancer, 2 had local relapse of cancer three to six months after the first operation. Four cases had cervical metastasis. All these 6 cases died within one year after operation. One case died of lung metastasis, two cases died of inflammation of lungs. Among 25 patients with cancers, the three-year survival rate was 50.0% (5/10).

CONCLUSION

For defects in hypopharynx and cervical esophagus less than 10 cm, silicone rubber tube reconstruction is satisfactory.

Effect of alpha-tocopherol, taurine and selenium on the attenuation of ischemia/reperfusion injury of splanchnic organs

BACKGROUND

Splanchnic artery occlusion shock is caused by increased capillary permeability and cellular injury precipitated by oxygen derived free radicals following ischemia and reperfusion of splanchnic organs. The purpose of this study was to assess the role of several well-known oxygen-derived free radical scavengers in ameliorating or preventing this syndrome.

STUDY DESIGN

Anesthetized rats were subjected to periods of occlusion of the visceral arteries and reperfusion. Tocopherol, taurine, selenium or a 'cocktail' of these three agents was injected subcutaneously for 4 consecutive days prior to operation. Mean arterial blood pressure was measured throughout the experimental period. Fluorometry and technetium-99m pyrophosphate counting of the visceral organs were performed as well as a histologic grading system for intestinal viability.

RESULTS

Final mean arterial blood pressure associated with the 'cocktail' and selenium groups was 79.1 +/- 27.4 mmHg and 83.6 +/- 17.8 mmHg, respectively. These values were significantly higher than the control group, 40.8 +/- 11.4 mmHg (P < 0.05). Similar patterns of the benefit of selenium in contrast with the other groups were obtained with fluorescein perfusion, radioisotopic activity and histologic analysis.

CONCLUSION

Pretreatment with selenium of splanchnic ischemia and reperfusion in the rat improves mean arterial blood pressure and microcirculatory visceral perfusion. Further analysis of the precise protective mechanism of selenium for reperfusion injury will enable visceral organs to withstand the consequences of increased capillary leakage and oxidant injury.