[An investigation of the advantages of the adjustable angle stitch template compared with CT-guided 125I seeds free-hand implantation in the treatment of non-small cell lung carcinoma].

Objective: To investigate the advantages of adjustable angle needle path template compared with CT-guided 125I seeds free-hand implantation in the treatment of non-small cell lung carcinoma. Methods: This randomized controlled trial involved the retrospective analysis of the clinical data of 45 patients with non-small cell lung carcinoma who underwent 125I seeds implantation at the Shandong Cancer Hospital, Shaanxi Provincial Tumor Hospital and The Third Affiliated Hospital of Shandong First Medical University from May 2018 to January 2023. Patients were divided into the template (n=21) and free-hand (n=24) groups, according to the modality used. The template group comprised 16 males and 5 females, aged (66±12) years, while the free-hand group comprised 16 males and 8 females, aged (62±8) years. The dose distribution, implant quality, intraoperative computed tomography (CT) scan times, and 125I seed reseeding numbers after implantation were compared between the two groups to evaluate the potential advantages of adjustable angle needle path template-assisted implantation over free-hand 125I implantation. Results: Statistical comparison revealed no significant differences in age (t=1.16, P=0.253), tumor volume [(71±26) vs. (71±22) cm3, t=0.21, P=0.837), or any other baseline characteristics between the template and free-hand groups. Overall, 45 patients successfully completed the operation. In the template group, the mean values of the D90 (dose that was delivered to 90% of the target volume), V100 (the target volume receiving 100% of the prescription dose), coverage index (CI), relative dose homogeneity index (HI), and external volume index (EI) pre-and post-implantation were (131.0±2.1) vs. (131.1±5.5) Gy, 90.0%±0.4% vs. 91.0%±2.8%, 0.83±0.07 vs. 0.82±0.05, 41%±11% vs. 37%± 13%, and 4.3%(2.9%, 14.0%) vs.8.8%(5.2%,14.6%), respectively. None of these parameters showed any significant difference (all P>0.05). In the free-hand group, the mean value of D90 pre- and post-implantation was (131.4±2.9) vs.(128.6±8.6) Gy, showing no significant difference (P>0.05), the mean values of V100, CI, HI, and EI pre-and post-implantation were 90.0%±0.5% vs. 89.0%± 3.0%, 0.84±0.04 vs. 0.71±0.09, 41%±9% vs. 34%±10%, and 7.7% (4.9%,11.0%) vs.24.2% (14.3%, 35.3%), respectively, showing significant differences (all P<0.05). The number of reseeding seeds in the template group was lower than that in the free-hand group [2.0 (0,2.5) vs. 4.0 (2.0, 7.0), Z=-3.36, P=0.001], showing a statistically significant difference. Further, the number of CT scans in the template group was significantly less than that in the free-hand group (3.9±0.5 vs. 4.6±1.2, t=-2.54, P=0.016). The incidences of adverse reactions were 23.8% (5/21) and 33.3% (8/24) (χ2=12.86, P=0.002) in the template and free-hand groups, respectively, indicating a significant difference. Conclusion: Compared with free-hand implantation, use of the adjustable angle needle path template technique can shorten the operation time, reduce the number of scans, reduce the incidence of complications, and improve treatment efficacy to a certain extent.

Measurement of serum estrogen and estrogen metabolites in pre- and postmenopausal women with osteoarthritis using high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry

Although 17β-estradiol (E2) deficiency has been linked to the development of osteoarthritis (OA) in middle-aged women, there are few studies relating other estrogens and estrogen metabolites (EMs) to this condition. We developed a high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method to measure the levels of six EMs (i.e., estrone, E2, estriol, 2-hydroxyestrone, 2-hydroxyestradiol, and 16a-hydroxyestrone) in healthy pre- and postmenopausal women and women with OA. This method had a precision ranging from 1.1 to 3.1% and a detection limit ranging from 10 to 15 pg. Compared to healthy women, serum-free E2 was lower in the luteal and postmenopausal phases in women with OA, and total serum E2 was lower in postmenopausal women with OA. Moreover, compared to healthy women, total serum 2-hydroxyestradiol was higher in postmenopausal women with OA and total serum 2-hydroxyestrone was lower in both the luteal and follicular phases in women with OA. In conclusion, our HPLC-ESI-MS/MS method allowed the measurement of multiple biochemical targets in a single assay, and, given its increased cost-effectiveness, simplicity, and speed relative to previous methods, this method is suitable for clinical studies.

Measurement of serum estrogen and estrogen metabolites in pre- and postmenopausal women with osteoarthritis using high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry.

Although 17ß-estradiol (E2) deficiency has been linked to the development of osteoarthritis (OA) in middle-aged women, there are few studies relating other estrogens and estrogen metabolites (EMs) to this condition. We developed a high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method to measure the levels of six EMs (i.e., estrone, E2, estriol, 2-hydroxyestrone, 2-hydroxyestradiol, and 16a-hydroxyestrone) in healthy pre- and postmenopausal women and women with OA. This method had a precision ranging from 1.1 to 3.1% and a detection limit ranging from 10 to 15 pg. Compared to healthy women, serum-free E2 was lower in the luteal and postmenopausal phases in women with OA, and total serum E2 was lower in postmenopausal women with OA. Moreover, compared to healthy women, total serum 2-hydroxyestradiol was higher in postmenopausal women with OA and total serum 2-hydroxyestrone was lower in both the luteal and follicular phases in women with OA. In conclusion, our HPLC-ESI-MS/MS method allowed the measurement of multiple biochemical targets in a single assay, and, given its increased cost-effectiveness, simplicity, and speed relative to previous methods, this method is suitable for clinical studies.

Targeted antiosteosarcoma methotrexate-bisphosphonate conjugate induces apoptosis of osteosarcoma cells in vitro.

OBJECTIVES: To investigate the effect of targeted antiosteosarcoma methotrexate-bisphosphonate conjugate on growth inhibition and apoptosis in human osteosarcoma MG-63 cells. MATERIALS AND METHODS: MG-63 cells were treated with various concentrations of methotrexate-bisphosphonate conjugate and apoptosis was monitored via an MTT assay, cell morphology, TUNEL assay and flow cytometry analysis. RESULTS: The survival rate of MG-63 cells treated for 24 to 96 hours with 2000 mg/ml or more of methotrexate-bisphosphonate conjugate decreased significantly. Cells treated with conjugate showed typical apoptotic features using inverted phase contrast microscopy and fluorescence staining, and the majority of cells demonstrated a positive result in the TUNEL assay. Karyopyknosis and crescent aggregation of chromatin were observed in conjugate-treated cells by electron microscopy. Flow cytometry of MG-63 cells treated with methotrexate-bisphosphonate conjugate showed a time and dose-dependent increase in apoptosis (p < 0.05). CONCLUSIONS: A targeted antiosteosarcoma methotrexate-bisphosphonate conjugate induces apoptosis in human osteosarcoma MG-63 cells. This new conjugate is a valuable experimental tool for the therapy of osteosarcoma.

Clinical observation on the efficacy of CyberKnife for primary or metastatic retroperitoneal tumours.

The aim of the paper is to evaluate the efficacy of CyberKnife® for the treatment of primary or metastatic retroperitoneal tumours. Twenty-eight patients were treated. The prescription isodose line (median, 78%; range, 70-84%) covered the planning target volume at a total dose of 2000-6000 cGy (median, 4500 cGy) and a biologically effective dose of 3750-10,080 cGy (median, 7680 cGy) in 2-10 fractions (median, five fractions). The results showed that the complete response, partial response, stable disease, and progressive disease rates were 43% (12/28), 36% (10/28), 18% (5/28), and 4% (1/28) respectively. The overall response rate was 96%. The 1-, 2- and 3-year local control rates were 92%, 86%, and 86% respectively. The 1-, 2- and 3-year overall survival rates were 60%, 49%, and 49% respectively. No significant difference was found between local progression-free survival and overall survival. Moreover, if a patient only had metastases in the retroperitoneum and local control was effective, there was no significant difference between local progression-free survival and overall progression-free survival. In conclusion, CyberKnife treatment for retroperitoneal tumours resulted in high response rates with minimal side effects. All radiation-induced side effects were well tolerated.

A preliminary probe into the movement of pancreatic lesions and factors that influence it.

The aim of this study was to investigate the movement, and the factors that influence such movement, of pancreatic lesions and to provide a reference for determination of planning target volume (PTV) during stereotactic radiotherapy. We implanted 19 gold markers into the inner pancreatic tumours of 16 pancreatic carcinoma patients percutaneously under B-ultrasonographic guidance. The marked motion of pancreatic lesions in the x (right-left), y (superoinferior) and z (anteroposterior) directions was measured using an X-ray simulator system. Based on the statistical analysis of the detected movements, we investigated the relevant influencing factors of pancreatic lesions with multinomial linear regression. Data showed that the mean motion amplitudes of pancreatic lesions were 0.16 cm +/- 0.06 (range 0.1-0.3 cm) in the x direction, 0.25 cm +/- 0.12 (range 0.1-0.4 cm) in the y direction and 0.88 cm +/- 0.24 (0.5-1.6 cm) in the z direction. Motion amplitude was not correlated with the height, weight or age of the patients nor with the location or size of the tumour. The motion of pancreatic lesions was mainly influenced by the respiratory motion and has maximal amplitude in the z direction. Therefore, motion in the z direction should be given a priority consideration while determining the PTV.

Rat Dlx5 is expressed in the subventricular zone and promotes neuronal differentiation

The molecular mechanisms and potential clinical applications of neural precursor cells have recently been the subject of intensive study. Dlx5, a homeobox transcription factor related to the distal-less gene in Drosophila, was shown to play an important role during forebrain development. The subventricular zone (SVZ) in the adult brain harbors the largest abundance of neural precursors. The anterior SVZ (SVZa) contains the most representative neural precursors in the SVZ. Further research is necessary to elucidate how Dlx5-related genes regulate the differentiation of SVZa neural precursors. Here, we employed immunohistochemistry and molecular biology techniques to study the expression of Dlx5 and related homeobox genes Er81 and Islet1 in neonatal rat brain and in in vitro cultured SVZa neural precursors. Our results show that Dlx5 and Er81 are also highly expressed in the SVZa, rostral migratory stream, and olfactory bulb. Islet1 is only expressed in the striatum. In cultured SVZa neural precursors, Dlx5 mRNA expression gradually decreased with subsequent cell passages and was completely lost by passage four. We also transfected a Dlx5 recombinant plasmid and found that Dlx5 overexpression promoted neuronal differentiation of in vitro cultured SVZa neural precursors. Taken together, our data suggest that Dlx5 plays an important role during neuronal differentiation.

Cytotoxic benzo[j]fluoranthene metabolites from Hypoxylon truncatum IFB-18, an endophyte of Artemisia annua.

Two new benzo[j]fluoranthene-based secondary metabolites named daldinone C (1) and daldinone D (2), along with two known metabolites, altechromone A and (4S)-5,8-dihydroxy-4-methoxy-alpha-tetralone, were isolated from the CHCl3/MeOH (1:1) extract of a solid culture of the endophyte Hypoxylon truncatum IFB-18 harbored inside the symptomless stem tissue of Artemisia annua. The structures of the new compounds were elucidated by MS and 1D and 2D NMR spectra and by X-ray diffraction analysis. Their absolute configurations were determined unambiguously by a combination of their CD data and the established exciton chirality rule. Compounds 1 and 2 were substantially cytotoxic against SW1116 cells, with IC50 values of 49.5 and 41.0 microM, respectively, comparable to that (37.0 microM) of 5-fluorouracil. The biosynthetic pathway for 1 and 2 was postulated with the natural occurrence of benzo[j]fluoranthene analogues discussed in brief.

New and cytotoxic anthraquinones from Pleospora sp. IFB-E006, an endophytic fungus in Imperata cylindrical.

In addition to 7-methoxy-2-methyl-3,4,5-trihydroxyanthraquinone (1), physcion (2), macrosporin (3), deoxybostrycin (4), altersolanol B (5) and dactylariol (6), a new hexahydroanthraquinone named pleospdione (7) was isolated from the culture of Pleospora sp . IFB-E006, an endophytic fungus residing in the normal stem of Imperata cylindrical (Gramineae). Structure determination of pleospdione was accomplished using IR, HR-ESI-MS, 1D and 2D NMR spectral analysis. Compounds 4 - 6 exhibited significant cytotoxic activity against human colon cancer (SW1116) and leukemia (K562) cell lines while compounds 1, 2 and 7 were only weakly or moderately active.

Endophytic naphthopyrone metabolites are co-inhibitors of xanthine oxidase, SW1116 cell and some microbial growths.

Fractionation of the extract of Aspergillus niger. IFB-E003, an endophyte in Cyndon dactylon, gave four known compounds naphtho-gamma-pyrones rubrofusarin B, fonsecinone A, asperpyrone B and aurasperone A, which were further investigated biologically. Rubrofusarin B was shown to be cytotoxic to the colon cancer cell line SW1116 (IC50: 4.5 microgml-1), and aurasperone A inhibitory on XO (xanthine oxidase) (IC50: 10.9 micromoll-1). Moreover, the four naphtho-gamma-pyrones exhibited growth inhibitions against the five test microbes with MICs ranging in between 1.9 and 31.2 microgml(-1). The present recognition of rubrofusarin B and aurasperone A as strong co-inhibitors on XO, colon cancer cell and some microbial pathogens is of significance for the imperative discovery of new relevant therapeutic agents.

FlaC, a protein of Campylobacter jejuni TGH9011 (ATCC43431) secreted through the flagellar apparatus, binds epithelial cells and influences cell invasion.

Type III secretion systems identified in bacterial pathogens of animals and plants transpose effectors and toxins directly into the cytosol of host cells or into the extracellular milieu. Proteins of the type III secretion apparatus are conserved among diverse and distantly related bacteria. Many type III apparatus proteins have homologues in the flagellar export apparatus, supporting the notion that type III secretion systems evolved from the flagellar export apparatus. No type III secretion apparatus genes have been found in the complete genomic sequence of Campylobacter jejuni NCTC11168. In this study, we report the characterization of a protein designated FlaC of C. jejuni TGH9011. FlaC is homologous to the N- and C-terminus of the C. jejuni flagellin proteins, FlaA and FlaB, but lacks the central portion of these proteins. flaC null mutants form a morphologically normal flagellum and are highly motile. In wild-type C. jejuni cultures, FlaC is found predominantly in the extracellular milieu as a secreted protein. Null mutants of the flagellar basal rod gene (flgF) and hook gene (flgE) do not secrete FlaC, suggesting that a functional flagellar export apparatus is required for FlaC secretion. During C. jejuni infection in vitro, secreted FlaC and purified recombinant FlaC bind to HEp-2 cells. Invasion of HEp-2 cells by flaC null mutants was reduced to a level of 14% compared with wild type, suggesting that FlaC plays an important role in cell invasion.

Nuclear extracellular signal-regulated kinase 2 phosphorylates p53 at Thr55 in response to doxorubicin.

In this study, we showed that nuclear ERK2 phosphorylates p53 at Thr55 in response to doxorubicin. p53 was found to physically interact with ERK2 as evidenced by Western blotting of ERK2 coimmunoprecipitated complex. The gene fragment encoded for N-terminal 68 amino acids was subcloned and fused with 6-His. Each serine or threonine site in this fragment, the possible phosphorylation site, was mutated to alanine. The recombinant proteins were used as substrates in ERK2 kinase assay. The results show that ERK2 phosphorylated p53 at Thr55. Further, electromobility shift assay showed that the phosphorylation of p53 by nuclear ERK2 was closely related to the transactivating activity of p53. These findings suggest that ERK2 may play a role in response to DNA damage via interaction with p53.

In vivo evaluation of the effects of a new ice-free cryopreservation process on autologous vascular grafts.

Conventionally cryopreserved vascular grafts have performed poorly as arterial grafts. One possible mechanism that causes the poor function is the extracellular ice damage in tissue. We used a novel new ice-free cryopreservation (namely, vitrification) method for prevention of ice formation in cryopreserved venous grafts. This study was designed to evaluate the in vivo effects of the vitrification process on autologous vascular grafts using a short-term transplantation model and to examine the morphology and patency of vitrified grafts in correlation with control grafts. New Zealand White rabbits underwent a right common carotid interposition bypass graft. Fresh and vitrified reversed ipsilateral external jugular veins were used as autologous grafts. Animals were sacrificed at either 2 or 4 weeks after implantation, and fresh and vitrified vein grafts were harvested for histology studies. The results, comparing the patency of fresh and vitrified grafts, demonstrated similar short-term patency rates (approximately 90%). There were no signs of media disruption, aneurysm, or graft stenosis in vitrified vein grafts. Vitrification had not altered the pathophysiological cascade of events that occur when a vein graft is inserted into the arterial system. The vitrification process had no adverse effects locally or systemically in vivo. In addition, vitrification has preserved endothelial cell and smooth muscle cell integrity posttransplantation. In conclusion, this study, using an autologous animal model, clearly demonstrated a significant benefit of vitrification for preservation of graft function, and vitrification may be an acceptable approach for preservation of blood vessels or engineered tissue constructs.

Interstitial ice formation in cryopreserved homografts: a possible cause of tissue deterioration and calcification in vivo.

BACKGROUND AND AIM OF THE STUDY: Cryopreserved valve homografts often fail in infants. Controversies are ongoing concerning the relative contributions of cryopreservation variables, immune responses, cellular viability, and durability of the extracellular matrix to the mode of tissue failure. METHODS: Tissues to be examined for patterns of ice crystal distribution were cryopreserved. Tissue water was substituted with methanol and the tissues cryopreserved conventionally using dimethylsulfoxide, after which they were warmed and processed for light or electron microscopy. Selected specimens were vitrified to prevent ice crystal formation, cryopreserved, and subsequently warmed and processed for light and electron microscopy. RESULTS: Cryosubstitution of conventionally cryopreserved heart valves, while still frozen, demonstrated extensive extracellular ice formation, with smaller crystals in the ventricularis than in either the spongiosa or fibrosa. Extracellular ice formation was prevented by vitrification, a process in which the biological system is stabilized as an amorphous solid in the absence of crystalline ice. CONCLUSION: It is proposed that the extensive ice formation observed in conventionally cryopreserved heart valves may cause extracellular matrix damage that predisposes the valves to calcification. Future studies will assess the above hypothesis by comparison of conventional and ice-free (vitrification) cryopreservation methods in animal models of calcification.

[Physical location and detection of homologous sequences of proto-oncogene ras on maize].

Proto-oncogene ras is an important gene for suppress the animal cells apoptosis. To analyze the presence of homologous sequences of ras in maize and rice, Southern blot hybridization was performed and positive signals was detected in these two species' genomes. The physical location of the ras homologous sequences was also carried out in maize chromosome by FISH. ras was hybridized onto the long arm of the chromosomes 2 and 7. The detection rates of FISH were 10.85% and 14.15%, and percentage distances from centromere to detection sites were 54.92 +/- 1.90 and 94.62 +/- 2.77 respectively. These results provided important clues of the further research of plant apoptosis.

[Salt stress-induced apoptosis in plants--a possible resistance mechanism to salt stress].

Previous study has showed that apoptosis-like cell death can be induced under moderate salt stress in plants. In this paper, we studied the cell death induced by salt stress in maize, rice and tobacco roots utilizing DNA Laddering, paraffin sectioning-based TUNEL and chromosome spreading-based TUNEL simultaneously. The characteristic morphological and biochemical features showed apoptosis induced by salt stress may be a universal phenomenon in plants, but some differences may lie in various species. These results provided a valuable insight into studying the physiological mechanism of stress resistance in plants. In addition, we compared the in situ labelling technique based on chromosome spreading with that based on paraffin sectioning. We proposed according to the results that chromosome spreading-based in situ labeling technique should be suitable to detect individual cell death qualitatively and quantitatively with high efficiency, low background and detailed description of apoptotic changes at chromosome, nuclear and DNA levels.

Temperature threshold and preservation of signaling for mitochondrial membrane proteins during ischemia in rabbit heart.

Temperature modulates both myocardial energy requirements and production. We have previously demonstrated that myocardial protection induced by hypothermic adaptation preserves expression of genes regulating heat shock protein and the nuclear-encoded mitochondrial proteins, the adenine nucleotide translocator isoform 1 (ANT1), and the beta subunit of F1-ATPase (beta F1-ATPase). This preservation is associated with a reduction in ATP depletion similar to that noted in cardioplegic arrested hearts preserved at a critical temperature (30 degrees C) or below. We tested the hypothesis that expression of these genes may also be subject to this temperature threshold phenomenon. Isolated perfused rabbit hearts were subjected to ischemic cardioplegic arrest at 4, 30, or 34 degrees C for 120 min. Cardiac function indices and steady-state mRNA levels for ANT1, beta F1-ATPase, and HSP70-1 were measured prior to ischemia (B) and after 45 min of reperfusion. Cardiac function was significantly depressed in the 34 degrees C group. Ischemia at 34 degrees C reduced steady-state mRNA levels for ANT1 and beta F1-ATPase from B, but these levels were similarly preserved at 4 and 30 degrees C. HSP70-1 levels were mildly elevated (fourfold) above B to similar levels at all three temperatures. These results indicate that mRNA expression for ANT1 and beta F1-ATPase is specifically preserved in a pattern consistent with the temperature threshold phenomenon. HSP70-1 expression is not influenced by ischemic temperature. Preservation of gene expression for these mitochondrial proteins implies that signaling for mitochondrial biogenesis or resynthesis is maintained after ischemic insult.

Hypothermia preserves function and signaling for mitochondrial biogenesis during subsequent ischemia.

Hypothermia is known to protect myocardium during ischemia, but its role in induction of a protective stress response before ischemia has not been evaluated. As cold incites stress responses in other tissues, including heat shock protein induction and signaling mitochondrial biogenesis, we postulated that hypothermia in perfused hearts would produce similar phenomena while reducing injury during subsequent ischemia. Studies were performed in isolated perfused rabbit hearts (n = 77): a control group (C) and a hypothermic group (H) subjected to decreasing infusate temperature from 37 to 31 degrees C over 20 min. Subsequent ischemia during cardioplegic arrest at 34 degrees C for 120 min was followed by reperfusion. At 15 min of reperfusion, recovery of left ventricular developed pressure (LVDP), maximum first derivative of left ventricular pressure (LV dP/dtmax), LV -dP/dtmax, and the product of heart rate and LVDP was significantly increased in H (P < 0.01) compared with C hearts. Ischemic contracture started later in H (97.5 +/- 3.6 min) than in C (67.3 +/- 3.3 min) hearts. Myocardial ATP preservation and repletion during ischemia and reperfusion were higher in H than in C hearts. mRNA levels of the nuclear-encoded mitochondrial proteins adenine nucleotide translocase isoform 1 (ANT1) and beta-F1-adenosine-triphosphatase (beta-F1-ATPase) normalized to 28S RNA decreased in C hearts but were preserved in H hearts after reperfusion. Inducible heat shock protein (HSP70-1) mRNA was elevated nearly 4-fold after ischemia in C hearts and 12-fold in H hearts. These data indicate that hypothermia preserves myocardial function and ATP stores during subsequent ischemia and reperfusion. Signaling for mitochondrial biogenesis indexed by ANT1 and beta-F1-ATPase mRNA levels is also preserved during a marked increase in HSP70-1 mRNA.

Temperature threshold and modulation of energy metabolism in the cardioplegic arrested rabbit heart.

Hypothermia protects ischemic tissues by reducing ATP utilization and accumulation of harmful metabolites. However, it also reduces ATP production, which might cause deterioration in the energy supply/demand ratio. Modulation of energy supply/demand according to temperature has not been previously studied in detail. In this study, isolated, perfused rabbit hearts (n = 60) were used to determine the effects of various temperatures on myocardial energy metabolism and function during cardioplegic arrest. Ischemia was induced by crystalloid cardioplegic solution at 4, 18, 30, and 34 degrees C for 120 min, respectively. At each temperature, the hearts were divided into a glucose-treated group which contained 22 mM glucose in cardioplegic solution as the only substrate and a control group which contained 22 mM mannitol to keep same osmolarity. Following 15 min reperfusion, recovery of left ventricular developed pressure (DP), +/- dP/dtmax, and the product of heart rate and DP were significantly higher in 30, 18, and 4 degrees C groups than those in 34 degrees C control group. The functional recovery was also significantly higher in the 34 degrees C glucose-treated group than that in the 34 degrees C control group, but there was no difference between those groups at 30 degrees C and the temperature below 30 degrees C. Myocardial ATP concentration was significantly lower in 34 degrees C control group than those in other groups. There is a close relationship between myocardial ATP concentration and functional recovery (R2 = 0.90). The accumulations of lactate and CO2 were significantly higher at 34 degrees C in glucose-treated group than those in the control group. However, there was no significant difference between these two groups at 30 degrees C and the temperature below 30 degrees C. These results indicate that under these study conditions: (1) a marked decrease in energy supply/demand occurs above 30 degrees C, implying that a temperature threshold exists; and (2) this can be ameliorated by provision of glucose as substrate in cardioplegia solution.

Effect of cryopreservation and histocompatibility on type I procollagen gene expression in aortic valve grafts.

BACKGROUND: Allograft valves are excellent substitutes for diseased or absent valves but undergo primary tissue degeneration. Fibroblast viability may determine resistance to valve deterioration. This study evaluated gene expression for procollagen by valve grafts and studied the effects of cryopreservation and histocompatibility on this property. METHODS AND RESULTS: Fresh and cryopreserved rat aortic valves were implanted heterotopically into syngeneic or allogeneic recipients. Nonviable, cryothermally injured valves were used as negative controls. The grafts and native aortic roots were excised 3 days after implantation. Northern hybridization with a human procollagen alpha 1 (I) complementary DNA probe was used to assess the expression of type I procollagen mRNA. The content of procollagen mRNA relative to 18S ribosomal RNA was evaluated by means of scanning densitometry. In situ hybridization was used to locate the areas of procollagen mRNA expression in the grafts. Both fresh and cryopreserved grafts exhibited greater expression than the native valve. This increase in expression was observed in both syngeneic and allogeneic grafts, but not in the negative control group. In situ hybridization showed a strong signal for procollagen in the aortic wall and a weak signal in the leaflet and myocardium in the viable grafts and in native tissues. CONCLUSIONS: Regardless of preservation or allogenicity, fibroblast viability in aortic valve grafts persists after implantation. Increased gene expression for procollagen suggests a capacity for repair and regeneration.