[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.

[Study on formulation and revision of standard limits for radon in "Standards for indoor air quality (GB/T 18883-2022)" in China].

Public exposure to radon has attracted increasing public concern. The newly issued "Standards for indoor air quality (GB/T 18883-2022)" has revised the radiological parameters of radon. This study analyzed and discussed the relevant technical contents about the derivation of radon limit, including the distribution level for indoor radon, exposure pathway, health effects, and the process for establishing the standard limits. Specific implementation and evaluation suggestions are also proposed.

Cryopreservation of the common carotid artery of the rabbit: Optimization of dimethyl sulfoxide concentration and cooling rate.

This paper describes the continuation of studies that demonstrated the suitability of CP-Tes solution as a medium for the introduction and removal of dimethyl sulfoxide in rabbit common carotid arteries and established the kinetics of cryoprotectant permeation in that tissue. In this paper we report the tolerance of rabbit common carotid artery to dimethyl sulfoxide, in concentrations up to 30% (w/w), using a technique of exposure that was designed to control osmotic stress. The maximum concentration achieved without damage was 15% (w/w). Vessels were then equilibrated with 15% dimethyl sulfoxide and cooled to -80 °C at 0.22, 0.69, 2.15, or 9.63 °C/min: they were then transferred to the gas phase of a liquid nitrogen refrigerator {temperature below -160 °C) for storage. Thawing was carried out in a 37 °C water bath. The optimum rate of cooling for these conditions was found to be 0.69 °C/min. The maximal recovery of contractile force in response to 10-6 M norepinephrine was 30-40%; relaxation to acetylcholine (an endothelium-mediated function) was 80% of control, and an estimated 71% of endothelial cells survived with minimal ultrastructural change.

[Epidemiology and molecular biology of respiratory syncytial virus among hospitalized children in Guangzhou from 2013 to 2017].

Objective: To understand the genetic variation and epidemiological characteristics of human respiratory syncytial virus (HRSV) in Guangzhou. Methods: Nasopharyngeal swabs specimens were collected from 0-6 year old children hospitalized with acute respiratory infection, then HRSV was tested and genotyped by RT-PCR. Phylogenetic tree was bulit using MEGA 6.0 software. NetNGlyc 1.0 server was used to predict the potential N-linked glycosylation sites. Results: A total of 1 225 nasopharyngeal specimens were collected, including 783 males and 442 females. The median (P(25), P(75)) age was 8 (3, 24) months. Among the 209 HRSV-positive cases (17.06%), 117 cases (55.98%) were HRSV-A and 92 cases (44.02%) were HRSV-B. The two distinct subgroups (HRSV-A and HRSV-B) alternately played dominant role to cause HRSV infection and exchange almost once every two years. The HRSV prevalence rate decreased with age. The HRSV-positive rate among children under 2 years old was 18.83% (196 cases), accounting for 93.78% of the total positive cases. There were 32 HRSV positive cases co-infected with at least one respiratory virus, with the co-infection rate of 15.31%. Phylogenetic tree analysis of the second hypervariable region (HVR2) of the G protein classified the HRSV-A specimens into ON1 (n=62) and NA1 (n=2) genotypes while all HRSV-B specimens belonged to BA genotype (n=53). The HVR2 of the G protein varied in using stop condon, amino acid substitutions, glycosylation sites. Conclusion: Children under 2 years old were the high risk population of HRSV infection in Guangzhou. ON1 genotype turned into a primary genetype of the HRSV-A subgroup while BA genotype dominated the HRSV-B subgroup. A greater diversification of amino acid substitutions, and some deletion and insertion of glycosylation sites embodied the polymorphism of G protein as main protective antigen.

Cultivation of a bacterial consortium with the potential to degrade total petroleum hydrocarbon using waste activated sludge.

Waste activated sludge was aerobically treated to demonstrate multiple uses such as cultivating an oil degrading bacterial consortium; studying the influence of a bulking agent (peat moss) and total petroleum hydrocarbon concentration on bacterial growth and producing a soil conditioner using waste activated sludge. After 30 days of incubation, the concentration of oil-degrading bacteria was 4.3 x 10(8) CFU g(-1) and 4.5 x 10(8) CFU g(-1) for 5 and 10 g of total petroleum hydrocarbon, respectively, in a mixture of waste activated sludge (1 kg) and peat moss (0.1 kg). This accounts for approximately 88.4 and 91.1%, respectively, of the total heterotrophic bacteria (total-HB). The addition of bulking agent enhanced total-HB population and total petroleum hydrocarbon-degrading bacterial population. Over 90% of total petroleum hydrocarbon degradation was achieved by the mixture of waste activated sludge, bulking agent and total petroleum hydrocarbon. The results of physico-chemical parameters of the compost (waste activated sludge with and without added peat moss compost) and a substantial reduction in E. coli showed that the use of this final product did not exhibit risk when used as soil conditioner. Finally, the present study demonstrated that cultivation of total petroleum hydrocarbon-degrading bacterial consortium and production of compost from waste activated sludge by aerobic treatment was feasible.

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.

Simultaneous immobilization of ammonium and phosphate from aqueous solution using zeolites synthesized from fly ashes.

Zeolites were synthesized from silica-rich (SF-Z) and calcium-rich (CF-Z) fly ashes, respectively, and their performance in immobilizing ammonium and phosphate was investigated through batch experiments. The cation exchange capacity and phosphate immobilization capacity of SF-Z were identified as 2.79 meq/g and 12.97 mg/g while those of CF-Z were 0.69 meq/g and 87.41 mg/g, respectively. The mixture of SF-Z and CF-Z (MSC-Z) immobilized simultaneously ammonium and phosphate, and the ratio of SF-Z to CF-Z depended on the ammonium and phosphate concentrations in wastewater and the discharge standard. The adsorption processes of ammonium and phosphate on MSC-Z followed Ho's pseudo-second-order model and the intra-particle diffusion was a rate-controlling step. The Langmuir model produced better suitability to the equilibrium data. The thermodynamic study revealed that the adsorption of both ammonium and phosphate on MSC-Z was an endothermic reaction. After treatment by MSC-Z, the ammonium and phosphate concentrations in wastewater from a sewage treatment plant decreased from 7.45 and 1.42 mg/L to 2.06 and 0.51 mg/L, respectively, and met Surface Water Environment Quality Standard in China δ. These results show that the immobilization of ammonium and phosphate in wastewater can be achieved by the combination of zeolites synthesized from silica-rich and calcium-rich fly ashes.

Short-term influence of phosphate and nitrate on heavy metal accumulation by red alga Acrosorium uncinatum.

Heavy metal accumulation (Cu, Zn, Ni, and Pb) in common marine macroalga, Acrosorium uncinatum under nutrient (phosphate and nitrate) enriched (experiment 1) and starved (experiment 2) conditions over a short exposure period (12 h) were examined in this study. Control was maintained in seawater contained nutrient solution without addition of metals and in seawater alone for experiment 1 and 2, respectively. Among the four metals studied, the accumulation of Zn, Ni, and Pb was considerably lower than Cu. The accumulation factor for all metals varies greatly in different nutrient concentrations, but it increases as the exposure of metal concentration decreases in both the experiments. The results of the present findings established that this macroalga is an accumulator of metals Cu, Zn, Ni, and Pb and have the potential to accumulate these metals even in a short time exposure period (12 h). Even though metal accumulation by A. uncinatum largely depends on the available concentration in the medium, nutrients like phosphate and nitrate can affect the accumulation significantly.

Effects of selected heavy metals (Pb, Cu, Ni, and Cd) in the aquatic medium on the restoration potential and accumulation in the stem cuttings of the terrestrial plant, Talinum triangulare Linn.

The heavy metal (Cu, Pb, Ni, and Cd) accumulation capacity of the stem cuttings of the terrestrial, ornamental plant, Talinum triangulare was assessed in hydroponic medium. The stem cuttings of T. triangulare, grew well in distilled water regenerating roots and aerial parts. On exposure to various concentrations of Cu, Pb, Ni, and Cd, a concentration dependent decrease was observed in the number of leaves produced and roots regenerated and an increase in the number of days required for the initiation of roots. The number of leaves produced showed an increasing trend in almost all treatment concentrations of Cu, Pb, Ni, and Cd with an increase in the duration of experiment, whereas, with an increase in the treatment concentration of metals a significant (P < 0.05) decrease was observed in the number of leaves produced. The number of days required for root initiation in metal solutions, however, increased with increasing concentration of Cu, Pb, Ni, and Cd. The root development was completely arrested from 10 mg l(-1) of Ni and 4 mg l(-1) of Cd. Compared to the control, a significant decrease was recorded in the number of roots produced in all treatment concentrations of Cu, Pb, Ni, and Cd. Pink colouration of metal solution consequent to leaching of plant pigment from T. triangulare was observed which was not persistent and disappeared after a few days. Decaying of stem was observed when exposed to Ni and Cd but not to Cu and Pb. Although, copper accumulation by T. triangulare at treatment concentration of 15 and 20 mg l(-1) exceeded 1,000 mg kg(-1) dry matter, necessary pot culture experiment is required before "T. triangulare" can be definitely classified as a Cu hyperaccumulator.

Cryoprotectant transport through articular cartilage for long-term storage: experimental and modeling studies.

OBJECTIVE: Long-term storage of articular cartilage (AC) remains challenging due to poor post-thaw viability. An initial step towards addressing this issue is characterizing cryoprotectant (CPA) transport, since ensuring adequate CPA equilibration throughout the tissue offers protection during cooling. This study takes a systematic approach in determining CPA transport rates through bovine AC and uses that information in mathematical models to determine CPA equilibration times. DESIGN: Diffusion of high concentration single (6.9 M dimethyl sulfoxide (DMSO)) and multi-component CPA solutions (VS55, 3.1 M DMSO+2.2 M 1,2-propanediol (PD)+3.1 M formamide (FM)) was measured through AC using (1)H nuclear magnetic resonance (NMR) imaging and localized spectroscopy, respectively. Using experimentally calculated effective diffusivities, diffusion models describing CPA transport through the tissue matrix and across chondrocyte membranes were combined to design a CPA addition and removal scheme for a cartilage plug of clinically relevant dimensions. RESULTS: (1)H NMR imaging and localized spectroscopy experiments suggested that the permeation of CPAs through AC (5 mm diameter, 5-10 mm in thickness) took on the order of 4 h for full equilibration at 22 degrees C. Imaging clearly showed the permeation of DMSO into cartilage over time and localized spectroscopy was able to distinguish the permeation rates of the individual VS55 components and water. Experimentally measured diffusivity values were used in CPA addition/removal simulations with a cartilage plug of clinically relevant dimensions (5 mm diameter, 2 mm in thickness). Results suggested a multi-step approach for adding and removing high concentration CPAs, with the addition and removal each taking approximately 2 h to complete. CONCLUSIONS: This study provides a foundation for designing CPA addition and removal protocols for effective long-term storage of cartilage tissue using a novel approach to measure CPA permeation.

Autism, early psychosis, and social anxiety disorder: understanding the role of social cognition and its relationship to disability in young adults with disorders characterized by social impairments.

Impairments in social cognition are believed contribute to disability, particularly for disorders characterized by difficulties in social interaction. There has been little transdiagnostic investigation of this across social cognition domains in young adults. A total of 199 young adults diagnosed with autism spectrum disorder (ASD; N = 53), early psychosis (EP; N = 51), and social anxiety disorder (SAD; N = 64) were compared against neurotypical controls (NT; N = 31) on a battery of lower and higher-order and self-report social cognition measures. For both ASD and EP, participants showed impaired performance on all lower-order emotion recognition tasks and one higher-order social cognition test. Self-reports of empathy were reduced in all clinical groups and particularly in ASD. For SAD, despite showing no objective social cognition impairment, self-reported empathy was reduced to the same level as EP. Discriminant analysis revealed that self-reported empathy and lower-order emotion recognition tests provide best capacity to differentiate groups. Regressions predicting disability revealed depression as the strongest predictor across all disability measures. Empathy provided additional predictive value for social disability and social interaction anxiety. Overall, results support a similar social-cognitive development profile across ASD and EP. While self-reported empathy differentiated between groups, discrepancy between objective social cognition test performance and self-reported empathy in the SAD group suggests probable threat-related self-monitoring report biases that likely further influence all group outcomes. As depression and empathy were the most important predictors of disability, regardless of diagnostic group, research is required to explore targeted interventions for difficulties in these domains to reduce disability.

Vitreous cryopreservation maintains the function of vascular grafts.

Avoidance of ice formation during cooling can be achieved by vitrification, which is defined as solidification in an amorphous glassy state that obviates ice nucleation and growth. We show that a vitrification approach to storing vascular tissue results in markedly improved tissue function compared with a standard method involving freezing. The maximum contractions achieved in vitrified vessels were >80% of fresh matched controls with similar drug sensitivities, whereas frozen vessels exhibited maximal contractions below 30% of controls and concomitant decreases in drug sensitivity. In vivo studies of vitrified vessel segments in an autologous transplant model showed no adverse effects of vitreous cryopreservation compared with fresh tissue grafts.

CPD staining: an effective technique for detection of NORs and other GC-rich chromosomal regions in plants.

Mitotic chromosome spreads of 16 plant species belonging to six families were analyzed using an improved combined PI and DAPI (CPD) staining procedure. Fluorescence in situ hybridization (FISH) with 45S rDNA probe was conducted sequentially on the same spreads to evaluate the efficiency and sensitivity of the technique. Fluorochrome staining with chromomycin A3 (CMA)-DAPI also was conducted to clarify the properties of the sequences involved in the CPD banded regions. Our results revealed that all of the NORs (rDNA sites) in the species tested were efficiently shown as red bands by CPD staining, and the number and position of the bands corresponded precisely to those of the 45S rDNA FISH signals, indicating that the detection sensitivity of CPD staining is similar to that of FISH. In 10 of the species tested including Aegilops squarrosa, Allium sativum, Oryza sativum ssp. indica, Oryza officinalis, Pisum sativum, Secale cereale, Setaria italica, Sorghum vulgare, Vicia faba and Zea mays, CPD bands were exhibited exclusively in their NORs, while in other six species including Hordeum vulgare, Allium cepa, Psophocarpus tetragonolobus, Arabidopsis thaliana, Brassica oleracea var. capitata and Lycopersicon esculentum, CPD bands appeared in chromosomal regions other than their NORs. The CPD bands were in accordance with the CMA bands in all species tested, indicating GC-rich sequences in the CPD bands and that the improved CPD staining procedure is specific for GC-rich regions in plant genomes. Our investigation not only elucidated the banding mechanisms of CPD, but also demonstrated that the CPD staining technique, which may be preferable to CMA staining, is an effective tool for detecting NORs and other GC-rich chromosomal regions in plants.

Purification, characterization and enzymatic degradation of YCP, a polysaccharide from marine filamentous fungus Phoma herbarum YS4108.

YCP, a mitogenic polysaccharide with its molecular weight (MW) of 2.4 x 10(3) kDa, was isolated from the mycelium of the marine filamentous fungus Phoma herbarum YS4108 by a combination of ion-exchange chromatography on DEAE-32 and gel permeation over Sephacryl S-400. The detailed compositional, spectroscopic and methylation analyses of the polysaccharide demonstrated that its backbone possessed most likely a linear alpha-(1 --> 4) bonded glucopyranoside main chain co-bearing through side alpha-(1 --> 6)-linkage. The alpha-(1 --> 4) bondage of the glucopyranoside building blocks in YCP was confirmed by the observation that it could be hydrolyzed by the alpha-amylase produced by Bacillus licheniformis. A reliable concentration monitoring experimentation highlighted that the reducing sugars released continuously from YCP during its incubation with the enzyme, and the MW of the main resulting fragment weighed 0.8 x 10(4) Da with approximately 10% of YCP converted to maltose, maltotriose and glucose after a 120-min enzymatic degradation. Finally, YCP was found to be able to increase phagocytic activity of mice in vitro and in vivo, indicating that it may be looked up as a potent immunomodulator that could activate macrophages.

Vitrification of tissue engineered pancreatic substitute.

Despite significant advances, some critical issues remain for the long-term storage of an engineered pancreas. In this study we employed a tissue engineered pancreatic substitute model-insulin-secreting betaTC3 cells entrapped in calcium alginate/poly-L-lysine/alginate beads-to demonstrate that a prototype vitrification method can prevent ice formation and maintain cell viability/function. The results showed that the structure of the frozen samples was distorted by ice crystals throughout the matrix. In marked contrast, the vitrified samples appeared to be free of ice. Morphologic studies demonstrated extensive fractures and vacuolation in frozen specimens while there were no fractures in vitrified TEPSs. Both vitrified and frozen constructs showed some vacuolization compared to the control samples. Frozen beads showed a significantly decreased viability compared to fresh controls and the VS55 group (P < .001). There was no significant difference between the vitrified and fresh samples. Vitrification using the VS55 protocol shows similar viability and secretion properties to the control group of fresh beads. Vitrification using the PEG 400 protocol resulted in slightly lower viability and secretion properties relative to the control group; conventional freezing resulted in even significantly lower viability and secretion properties. These results combine to demonstrate feasibility of vitrification as a storage method for a tissue engineered pancreas.

A study on the treatment of antifouling paint waste from shipyard.

A study on the treatment of antifouling paint waste from shipyards, including sandblast waste and ship hull washing wastewater, was performed. The sandblast waste could be effectively detoxified by heat treatment, and the efficiency was affected by the temperature of the heating vessel and treatment time. The removal efficiency of total organotin compounds from the sandblast waste was over 99% at 1000 degrees C and treatment for 1 h. For the treatment of ship hull washing wastewater by the solvent extraction, ship diesel was a good solvent for the tributyltin (TBT) extraction, and the proper amount of solvent was about 10 mL for TBT extraction from 1L of wastewater. The extraction efficiency of TBT was significantly affected by the agitation intensity. The TBT in the wash wastewater was rapidly extracted within 1 h. The level of the TBT residual in the wastewater extracted for 1h was 2.8 microg L(-1), and this was further decreased to 0.8 after 5 h extraction.

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.

Molecular cytogenetic characterization of a familial balanced reciprocal translocation t(11;18) (q13.3; q23) associated with pregnancy wastage.

A new male patient associated with a pregnancy wastage was detected in China. Cytogenetic analyses including G-banding, chromosome painting and observation of synaptonemal complexes (SCs) demonstrated that the pregnancy wastage was associated with a balanced reciprocal translocation t(11;18) (q13.3; q23). The proband was the carrier of the translocation and his karyotype was 46,XY,t(11;18)(11pter-->11q13.3:: 18q23-->18qter; 18pter-->18q23::11q13.3-->11qter). The pedigree was analyzed based on a G-banded karyotype of the nine familial members. The translocation chromosomes came from the proband's mother. The result of the SC observation in the proband showed that each of the spermatocytes displayed one quadrivalent during their pachytene stages. In the quadrivalents, there existed homologous and nonhomologous synapses and the latter occurred widely during early, middle and late pachytene stages. The reasons and genetic basis of the pregnancy wastage are discussed.

Effects of enalapril on heart rate variability in patients with congestive heart failure.

Congestive heart failure (CHF) is characterized by sympathetic activation and parasympathetic withdrawal, and the magnitude of sympathoneural activation is associated with adverse outcome. Angiotensin-converting enzyme inhibitor therapy has been shown to reduce mortality and improve prognosis in patients with CHF, but whether this therapy improves cardiac autonomic control is not well known. This double-blind, placebo-controlled, crossover study examines the effects of enalapril on autonomic control in 12 patients with mild to moderate CHF by heart rate variability analysis. Compared with placebo, enalapril increased the SD of all normal RR intervals (SDNN) from 39 +/- 13 to 48 +/- 15 ms (p < 0.01), the SD of the average RR intervals for all 5-minute segments from 33 +/- 12 to 42 +/- 15 ms (p < 0.01), and the mean of the SDs of all RR intervals for all 5-minute segments (SDNN index) from 19 +/- 5 to 23 +/- 6 ms (p < 0.01). The root-mean-square successive differences and the percent differences between adjacent RR intervals > 50 ms were also increased from 17 +/- 8 to 21 +/- 8 ms (p < 0.01) and from 1.1 +/- 2.1 to 2.8 +/- 2.9% (p < 0.05). In addition, total, low-frequency, and high-frequency power were increased from 560 +/- 349 to 786 +/- 504 ms2/Hz (p < 0.01), from 125 +/- 107 to 179 +/- 135 ms2/Hz (p < 0.01), and from 46 +/- 32 to 94 +/- 78 ms2/Hz (p < 0.01), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

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.