Personal inhalation exposure to polycyclic aromatic hydrocarbons in urban and rural residents in a typical northern city in China

Personal inhalation exposure samples were collected and analyzed for polycyclic aromatic hydrocarbons (PAHs) for 126 selected volunteers during heating and non-heating seasons in a typical northern Chinese city, Taiyuan. Measured personal PAH exposure levels for the urban residents in the heating and non-heating seasons were 690 (540-1051) and 404 (266-544) ng/m(3) , respectively, while, for the rural residents, they were 770 (504-1071) and 312 (201-412) ng/m(3) , respectively. Thus, rural residents are exposed to lower PAH contamination in comparison with the urban residents in the non-heating seasons. In the heating season, personal PAH inhalation exposure levels were comparable between the urban and rural residents, in part owing to the large rate of residential solid fuel consumption in the rural area for household cooking and heating. The estimated incremental lifetime cancer risks (ILCR) due to PAH exposure in Taiyuan were 3.36 × 10(-5) and 2.39 × 10(-5) for the rural and urban residents, respectively, significantly higher than the literature-reported national average level, suggesting an urgent need of PAH pollution control to protect human health.

Characterization of small interfering RNAs derived from Sugarcane mosaic virus in infected maize plants by deep sequencing

RNA silencing is a conserved surveillance mechanism against viruses in plants. It is mediated by Dicer-like (DCL) proteins producing small interfering RNAs (siRNAs), which guide specific Argonaute (AGO)-containing complexes to inactivate viral genomes and may promote the silencing of host mRNAs. In this study, we obtained the profile of virus-derived siRNAs (vsiRNAs) from Sugarcane mosaic virus (SCMV) in infected maize (Zea mays L.) plants by deep sequencing. Our data showed that vsiRNAs which derived almost equally from sense and antisense SCMV RNA strands accumulated preferentially as 21- and 22-nucleotide (nt) species and had an adenosine bias at the 5′-terminus. The single-nucleotide resolution maps revealed that vsiRNAs were almost continuously but heterogeneously distributed throughout the SCMV genome and the hotspots of sense and antisense strands were mainly distributed in the HC-Pro coding region. Moreover, dozens of host transcripts targeted by vsiRNAs were predicted, several of which encode putative proteins involved in ribosome biogenesis and in biotic and abiotic stresses. We also found that ZmDCL2 mRNAs were up-regulated in SCMV-infected maize plants, which may be the cause of abundant 22-nt vsiRNAs production. However, ZmDCL4 mRNAs were down-regulated slightly regardless of the most abundant 21-nt vsiRNAs. Our results also showed that SCMV infection induced the accumulation of AGO2 mRNAs, which may indicate a role for AGO2 in antiviral defense. To our knowledge, this is the first report on vsiRNAs in maize plants.

Rapid and efficient isolation of high-quality small RNAs from recalcitrant plant species rich in polyphenols and polysaccharides

Small RNAs, including microRNAs (miRNAs) and small interfering RNAs (siRNAs), are important regulators of plant development and gene expression. The acquisition of high-quality small RNAs is the first step in the study of its expression and function analysis, yet the extraction method of small RNAs in recalcitrant plant tissues with various secondary metabolites is not well established, especially for tropical and subtropical plant species rich in polysaccharides and polyphenols. Here, we developed a simple and efficient method for high quality small RNAs extraction from recalcitrant plant species. Prior to RNA isolation, a precursory step with a CTAB-PVPP buffer system could efficiently remove compounds and secondary metabolites interfering with RNAs from homogenized lysates. Then, total RNAs were extracted by Trizol reagents followed by a differential precipitation of high-molecular-weight (HMW) RNAs using polyethylene glycol (PEG) 8000. Finally, small RNAs could be easily recovered from supernatant by ethanol precipitation without extra elimination steps. The isolated small RNAs from papaya showed high quality through a clear background on gel and a distinct northern blotting signal with miR159a probe, compared with other published protocols. Additionally, the small RNAs extracted from papaya were successfully used for validation of both predicted miRNAs and the putative conserved tasiARFs. Furthermore, the extraction method described here was also tested with several other subtropical and tropical plant tissues. The purity of the isolated small RNAs was sufficient for such applications as end-point stem-loop RT-PCR and northern blotting analysis, respectively. The simple and feasible extraction method reported here is expected to have excellent potential for isolation of small RNAs from recalcitrant plant tissues rich in polyphenols and polysaccharides.

A Biomimetic Collagen-Apatite Scaffold with a Multi-Level Lamellar Structure for Bone Tissue Engineering

Collagen-apatite (Col-Ap) scaffolds have been widely employed for bone tissue engineering. We fabricated a Col-Ap scaffold with a unique multi-level lamellar structure consisting of co-aligned micro and macro pores. The basic building blocks of this scaffold are bone-like mineralized collagen fibers developed via a biomimetic self-assembly process in a collagen-containing modified simulated body fluid (m-SBF). This biomimetic method preserves the structural integrity and great tensile strength of collagen by reinforcing the collagen hydrogel with apatite nano-particles. Unidirectional aligned macro pores with a size of 63.8 to 344 μm are created by controlling the freezing rate and direction. The thickness of Col-Ap lamellae can be adjusted in the range 3.6 to 23 μm depending on the self-compression time. Furthermore, the multi-level lamellar structure has led to a twelve-fold increase in Young's modulus and a two-fold increase in the compression modulus along the aligned direction compared to a scaffold of the same composition with an isotropic equiaxed pore structure. Moreover, this novel lamellar scaffold supports the attachment and spreading of MC3T3-E1osteoblasts. Therefore, owing to the biomimetic composition, tunable structure, improved mechanical strength, and good biocompatibility of this novel scaffold, it has great potential to be used in bone tissue engineering applications.

Effects of the probiotic Arthrobacter sp. CW9 on the survival and immune status of white shrimp (Penaeus vannamei)

The probiotic Arthrobacter sp. CW9 isolated from guts of white shrimp (Penaeus vannamei) was used to improve the survival rate, growth rate and immune status of white shrimp (P. vannamei). Arthrobacter sp. CW9 was added to the saline rearing water at 0, 10(5), 10(6) and 10(7) CFU ml(-1) once every 5 days during the 24-day breeding experiment. The probiotic group had significantly higher survival rates, mean shrimp weights, phenoloxidase activity, phagocytic activity and clearance efficiency compared with the control group (P < 0.05). Therefore, Arthrobacter sp. CW9 has both probiotic and immunostimulatory properties.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates that Arthrobacter sp. CW9 has both probiotic and immunostimulatory properties. Such new strain therefore represents an alternative to the use of white shrimp (Penaeus vannamei) culture. New bacterial having both probiotic and immunostimulatory properties are the major novelty of this study. The results are of industrial relevance.

Reversal of dopamine neurons and locomotor ability degeneration in aged rats with smilagenin

The purpose of this paper is to study the effect of smilagenin (SMI) (PYM50028), a sapogenin compound originally identified from Chinese medicinal herb, on dopamine neurons and locomotor ability in aged rats. Experiments were carried out on young and aged Sprague-Dawley rats, which were daily administered with either SMI (18mg/kg/day) or vehicle (0.5% sodium carboxymethycellulose [CMCNa]). Open-field and rotarod performance tests revealed that behavioral ability was impaired in aged rats and was improved by oral administration of smilagenin. Immunohistochemical data showed that tyrosine hydroxylase (TH)-positive neuron numbers in the substantia nigra pars compacta (unbiased stereological counting) were altered with aging and were increased by smilagenin treatment. Likewise, the dopamine receptor density and the striatal dopamine transporter (DAT) density ((125)I-2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane [(125)I-FP-CIT] autoradiography) were significantly lowered in aged rats as compared to young rats, and treatment with smilagenin significantly elevated the dopamine receptor and DAT density in aged rats. Furthermore, smilagenin enhances glial cell-derived neurotrophic factor (GDNF) release both in the striatum and midbrain. These results indicate a possible role of smilagenin in the treatment of age-related extrapyramidal disorders.

Recombinant PTD-Cu/Zn SOD attenuates hypoxia-reoxygenation injury in cardiomyocytes

BACKGROUND

Oxidative stress plays a pivotal role in myocardial ischemia-reperfusion injury. Increasing the protein expression of intracellular Cu/Zn SOD, which is the major endogenous antioxidant enzyme, may attenuate or prevent hypoxia-reoxygenation injury (HRI) in cultured cardiomyocytes. However, ectogenic Cu/Zn-SOD can hardly be transferred into cells to exert biological effects. In this study, we constructed PTD-Cu/Zn SOD plasmid with a kind of translocation structure-Protein transduction domain (PTD) and detected its transmembrane ability and antioxidant effects in H9c2 rat cardiomyocytes subjected to hypoxia/reoxygenation injury (HRI).

METHODS

We constructed the pET-PTD-Cu/Zn SOD (CDs) prokaryotic expression vectors in plasmid that were inserted into E. coli BL21 to induce the protein expression of PTD-Cu/Zn SOD. H9c2 cardiomyocyte HRI was achieved by exposing cardiomyocytes to 12 h hypoxia followed by 2 h reoxygenation. Protein expression of PTD-Cu/Zn SOD in cardiomyocytes was assayed by Western blot and their enzyme activities were investigated by immunohistochemistry and flow cytometry.

RESULTS

In cultured cardiomyocytes hypoxia-reoxygenation injury model, exogenous PTD-Cu/Zn SOD could penetrate cell membrane to clear superoxide anion and decrease hydrogen peroxide level in H9c2 cardiomyocytes subjected to HRI. The level of mitochondrial membrane potential was restored to normal, and the cell apoptosis was reduced in cardiomyocytes with PTD-Cu/Zn SOD treatment during HRI.

CONCLUSION

Recombinant PTD-Cu/Zn SOD could scavenge intracellular-free superoxide anion, protect mitochondria from damages, and attenuate the hypoxia-reoxygenation injury in cultured cardiomyocytes.

p53 protein accumulation and genetic alterations in human giant cell tumors of bone (osteoclastomas)

Inactivation of tumor suppressor genes represents a critical determinant in the development of a large proportion of human cancers. The tumor suppressor gene p53 is the most frequently altered gene in human cancers. In the present study, p53 protein accumulation, gene mutation and the association between p53 alteration and clinicopathological parameters was analyzed in 29 giant cell tumors of bone. p53 overexpression was detected by immunohistochemistry in 23 of 29 (79%) primary tumors but not in adjacent bone tissue. p53 gene mutations in exons 5-8 were detected in 15 of 29 (52%) of the tumors by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. In 15 (52%) of 29 patient specimens, p53 immunostaining and mutations in exons 5-8 were concordant. Eleven (38%) of 29 tumors overexpressed p53 in the absence of mutations in exons 5-8. No significant association between p53 alterations and clinicopathological parameters was found. The present study represents the first report to assess p53 protein content and gene mutation in a substantial number of giant cell tumors of bone and suggests that p53 alterations play an important role in the development of this neoplasm.

Smilagenin attenuates beta amyloid (25-35)-induced degeneration of neuronal cells via stimulating the gene expression of brain-derived neurotrophic factor

The development of drugs that attenuate neurodegeneration is important for the treatment of Alzheimer's disease (AD). We previously found that smilagenin (SMI), a steroidal sapogenin from traditional Chinese medicinal herbs improves memory in animal models, is neither a cholinesterase inhibitor nor a glutamate receptor antagonist, but can significantly elevate the declined muscarinic receptor (M receptor) density. In this article, to clarify whether SMI represents a new approach for treating neurodegeneration disease, we first demonstrate that SMI pretreatment significantly attenuates the neurodegenerative changes induced by beta amyloid 25-35 (Aβ(25-35)) in cultured rat cortical neurons, including decreased cholinergic neuron number, shortened neurite outgrowth length, and declined M receptor density. Brain-derived neurotrophic factor (BDNF) protein levels in the culture medium were also decreased by Aβ(25-35) and significantly elevated by SMI. Parallel experiments revealed that when the trk receptors were inhibited by K252a or the action of BDNF was inhibited by a neutralizing anti-BDNF antibody, the effects of SMI on the Aβ(25-35)-induced neurodegeneration in rat cortical neurons were almost completely abolished. In the all-trans retinoic acid (RA)-differentiated SH-SY5Y neuroblastoma cells, the BDNF transcription rate measured by a nuclear run-on assay was significantly suppressed by Aβ(25-35) and elevated by SMI, but the BDNF degradation rate measured by half-life determination was unchanged by Aβ(25-35) and SMI. Transcript analysis of the SH-SY5Y cells using quantitative RT-PCR (qRT-PCR) showed that the IV and VI transcripts of BDNF mRNA were significantly decreased by Aβ(25-35) and elevated by SMI. Taken together, we conclude that SMI attenuates Aβ(25-35)-induced neurodegeneration in cultured rat cortical neurons and SH-SY5Y cells mainly through stimulating BDNF mRNA transcription implicating that SMI may represent a novel therapeutic strategy for AD.

Effects of chronic immobilization stress on anxiety-like behavior and basolateral amygdala morphology in Fmr1 knockout mice

Several lines of clinical evidence support the idea that fragile X syndrome (FXS) may involve a dysregulation of hypothalamic-pituitary-adrenal axis function [Wisbeck et al. (2000) J Dev Behav Pediatr 21:278-282; Hessl et al. (2002) Psychoneuroendocrinology 27:855-872]. We had tested this idea in a mouse model of FXS (Fmr1 KO) and found that the hormonal response to acute stress was similar to that of wild-type (WT) mice [Qin and Smith (2008) Psychoneuroendocrinology 33:883-889]. We report here responses to chronic stress (CS) in Fmr1 KO mice. Following restraint for 120 min/d, 10 consecutive days, we assessed dendrite and spine morphology in basolateral amygdala (BLA). We also monitored behavior in an elevated plus maze (EPM) and the hormonal response to this novel spatial environment. After CS, mice of both genotypes underwent adrenal hypertrophy, but effects were greater in WT mice. Behavior in the EPM indicated that only WT mice had the expected increase in anxiety following CS. Serum corticosterone and adrenocorticotropic hormone (ACTH) levels were both increased following the spatial novelty of EPM, and there were no differences between genotypes in the hormonal responses. BLA dendritic branching increased proximal to the soma in WT, but in Fmr1 KO mice branching was unaffected close to the soma and slightly decreased at one point distal to the soma. Similarly, spine density on apical and basal dendrites increased in WT but decreased in Fmr1 KO mice. Spine length on apical and basal dendrites increased in WT but was unaffected in Fmr1 KO mice. These differences in behavioral response and effects on neuron morphology in BLA suggest a diminished adaptive response of Fmr1 KO mice.

A study on optimal bonding angles of bi-material interfaces in dental crowns with porcelain fused to metal

Interfaces between two different materials exist in the dental crowns used in dental restoration work. A common failure mode observed in dental crowns is debonding/fracture that is initiated at the corners of the interface between two materials, where a stress concentration or a stress singularity can be created. In this paper, finite element modelling and analytical methods are used to analyse the stress singularity at the free edge corners at the interfaces between porcelain and metal and also metal and cement in porcelain-fused-to-metal (PFM) crowns. Optimal ranges of bonding angles at the corners of the interface, that result in the elimination of the stress singularity, are obtained for PFM crowns made from a precious-metal-based or non-precious-metal-based alloy, respectively. The findings presented in this paper can serve as guidelines for the design and manufacture of PFM dental crowns.

The feasibility of light microscopic measurements of intercellular spaces in squamous epithelium in the lower-esophagus of GERD patients

The study aims to determine whether light microscopy can be used to accurately measure the diameters of intercellular spaces between squamous epithelial cells in the lower esophagus, and whether changes in this outcome measure can be used as a diagnostic marker for gastroesophageal reflux disease (GERD). The study has two parts. Part 1 involves 42 asymptomatic controls and 119 patients with typical symptoms of GERD, including 58 with erosive esophagitis (EE), and 61 patients with nonerosive gastroesophageal reflux disease (NERD). All biopsies were taken from the lower esophagus. All samples were observed using an immersion objective, after which diameters were measured by computer-assisted morphometry. Part 2 involves 61 individuals who were randomly selected from part 1, including 19 controls, 13 with NERD and 29 with EE. Diameter measurements using both light microscopy and transmission electron microscopy (TEM) were performed for samples of 61 individuals. Samples from a total of 61 individuals (31 male, 30 female, mean age 44.3 ± 16.0 years) were observed using both light microscopy and TEM. Both methods showed significant differences between control and disease groups; the outcomes from the two methods had a certain correlation (r = 0.605, P = 0.000). Morphometric analysis of all 161 individuals (83 males, 78 females, mean age 41.4 ± 15.7) showed mean diameters from light microscopy to be 0.58 ± 0.16 µm for controls, 1.07 ± 0.30 µm for NERD, and 1.29 ± 0.20 µm for EE; differences between control and disease groups were significant (P<0.05). The optimal cut-off value from receiver operator characteristic analysis was 0.85 µm. Diagnoses were validated using the combination of symptoms of GERD, endoscopy, and 24 h ambulatory pH monitoring as the gold standard. At the optimal cutoff, sensitivity was 93.3% and specificity was 100%. The diameters of the intercellular spaces in squamous epithelium of lower esophagus from controls and in patients with GERD can be quantitatively measured using light microscopy. Dilated diameters can serve as a sensitive, specific, and objective indicator for diagnosis of GERD.

Remote pharmacological post-conditioning by intrathecal morphine: cardiac protection from spinal opioid receptor activation

BACKGROUND

Intrathecal morphine pre-conditioning attenuates cardiac ischemia-reperfusion injury via activation of central opioid receptors. We hypothesized that intrathecal morphine also post-conditions the myocardium in the rat.

METHODS

Intrathecal morphine at 0.3 μg/kg (LMPC), 3 μg/kg (MMPC) or 30 μg/kg (HMPC) was administered for 5 min before 120-min reperfusion following 30-min ischemia. Infarct size as a percentage of area at risk (IS/AAR) was determined using triphenyltetrazolium staining. MMPC was repeated following the intrathecal administration of nor BNI, NTD, CTOP, or naloxone methiodide (NM), kappa, delta, mu and non-specific opioid receptor antagonists, respectively. The role of peripheral opioid, adenosine and calcitonin gene-related peptide (CGRP) receptors was examined by the intravenous administration of NM, 8-ρ-sulfophenyl theophylline (8-SPT) and human CGRP fragment (CGRP(8-37)), respectively.

RESULTS

Morphine post-conditioning at all three doses was cardioprotective (IS/AAR of LMPC=37 ± 4%, MMPC=35 ± 5%, HMPC=32 ± 4%, control=50 ± 5%, P<0.01). The prior administration of opioid receptor antagonists intrathecally, as well as intravenous 8-SPT and CGRP(8-37) receptor antagonists, abolished this effect (nor BNI+MMPC=47 ± 7%, NTD+MMPC=49 ± 7%, CTOP+MMPC=45 ± 9%, NM+MMPC=47 ± 6% 8-SPT+MPC=46 ± 5% & CGRP(8-37)+MPC=53 ± 6%, P=0.63). However, the intravenous administration of NM did not prevent the protective effect (34 ± 4%, P<0.01).

CONCLUSIONS

Intrathecal morphine administration can induce pharmacological cardiac post-conditioning as it involves opioid receptor centrally but non-opioid receptors peripherally.

Disruption of the SCN2A and SCN3A genes in a patient with mental retardation, neurobehavioral and psychiatric abnormalities, and a history of infantile seizures

Mutations in genes encoding voltage-gated sodium channels are significant factors in the etiology of neurological diseases and psychiatric disorders, including various types of idiopathic epilepsy. Using a clinical exon-targeted oligonucleotide array comparative genomic hybridization (aCGH), we have identified a de novo ~110-kb deletion involving exons 1-2 of SCN2A and non-coding exon 1a of SCN3A in a 25-year-old female with mental retardation, neurobehavioral and psychiatric abnormalities, and a history of infantile seizures with abnormal EEG. We propose that haploinsufficiency of SCN2A may play an important role in the genetic basis of neurodevelopmental and neurobehavioral disorders and emphasize the efficacy of detecting exonic copy-number variation (CNV) by exon-targeted oligo aCGH.

Differences between bisphosphonates in binding affinities for hydroxyapatite

Bisphosphonates (BPs) inhibit bone resorption and are widely used for the treatment of bone diseases, including osteoporosis. BPs are also being studied for their effects on hydroxyapatite (HAP)-containing biomaterials. There is a growing appreciation that there are hitherto unexpected differences among BPs in their mineral binding affinities that affect their pharmacological and biological properties. To study these differences, we have developed a method based on fast performance liquid chromatography using columns of HAP to which BPs and other phosphate-containing compounds can adsorb and be eluted by using phosphate buffer gradients at pH 6.8. The individual compounds emerge as discrete and reproducible peaks for a range of compounds with different affinities. For example, the peak retention times (min; mean +/- SEM) were 22.0 +/- 0.3 for zoledronate, 16.16 +/- 0.44 for risedronate, and 9.0 +/- 0.28 for its phosphonocarboxylate analog, NE10790. These results suggest that there are substantial differences among BPs in their binding to HAP. These differences may be exploited in the development of biomaterials and may also partly explain the extent of their relative skeletal retention and persistence of biological effects observed in both animal and clinical studies.

Catalpol attenuates MPTP induced neuronal degeneration of nigral-striatal dopaminergic pathway in mice through elevating glial cell derived neurotrophic factor in striatum

The protective effect of an iridoid catalpol extracted and purified from the traditional Chinese medicinal herb Rehmannia glutinosa on the neuronal degeneration of nigral-striatal dopaminergic pathway was studied in a chronic 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine (MPTP)/probenecid C57BL/6 mouse model and in 1-methyl-4-phenylpyridimium (MPP(+)) intoxicated cultured mesencephalic neurons. Rotarod performance revealed that the locomotor ability of mice was significantly impaired after completion of model production and maintained thereafter for at least 4 weeks. Catalpol orally administered for 8 weeks (starting from the second week of model production) dose dependently improved the locomotor ability. HPLC revealed that catalpol significantly elevated striatal dopamine levels without changing the metabolite/dopamine ratios. Nor did it bind to dopamine receptors. Therefore it is unlikely that catalpol resembles any of the known compounds for treating Parkinsonism. Instead, catalpol dose dependently raised the tyrosine hydroxylase (TH) neuron number in substantia nigra pars compacta (SNpc), the striatal dopamine transporter (DAT) density and the striatal glial cell derived neurotrophic factor (GDNF) protein level. Linear regression revealed that both the TH neuron number and DAT density were positively correlated to the GDNF level. In the cultured mesencephalic neurons, MPP(+) decreased the dopaminergic neuron number and shortened the neurite length, whereas catalpol showed protective effect dose dependently. Furthermore, the expression of GDNF mRNA was up-regulated by catalpol to a peak nearly double of normal control in neurons intoxicated with MPP(+) for 24 h but not in normal neurons. The GDNF receptor tyrosine kinase RET inhibitor 4-amino-5-(4-methyphenyl)-7-(t-butyl)-pyrazolo-[3,4-d]pyrimidine (PP1) abolished the protective effect of catalpol either partially (TH positive neuron number) or completely (neurite length). Taken together, catalpol improves locomotor ability by attenuating the neuronal degeneration of nigral-striatal dopaminergic pathway, and this attenuation is at least partially through elevating the striatal GDNF expression.

Multiwall nanotubes can be stronger than single wall nanotubes and implications for nanocomposite design

Molecular dynamics modeling shows that multiwall carbon nanotubes (MWCNTs) with sp;{3} interwall bonding have strengths exceeding those of single-wall carbon nanotubes (SWCNTs) containing the same size initial intrawall defect, and are far less sensitive to defect size. Thus, although processing methods used to increase interwall coupling also create intrawall defects, analyses here show that the strengthening effects and enhanced load transfer compensate for the creation of defects and make MWCNTs with interwall bonding preferable to SWCNTs as mechanical reinforcements in composites. These results are consistent with new experimental data and suggest a new design methodology for CNT-based composites.

The viability and proliferation of human chondrocytes following cryopreservation

Human articular cartilage samples were retrieved from the resected material of patients undergoing total knee replacement. Samples underwent automated controlled freezing at various stages of preparation: as intact articular cartilage discs, as minced articular cartilage, and as chondrocytes immediately after enzymatic isolation from fresh articular cartilage. Cell viability was examined using a LIVE/DEAD assay which provided fluorescent staining. Isolated chondrocytes were then cultured and Alamar blue assay was used for estimation of cell proliferation at days zero, four, seven, 14, 21 and 28 after seeding. The mean percentage viabilities of chondrocytes isolated from group A (fresh, intact articular cartilage disc samples), group B (following cryopreservation and then thawing, after initial isolation from articular cartilage), group C (from minced cryopreserved articular cartilage samples), and group D (from cryopreserved intact articular cartilage disc samples) were 74.7% (95% confidence interval (CI) 73.1 to 76.3), 47.0% (95% CI 43 to 51), 32.0% (95% CI 30.3 to 33.7) and 23.3% (95% CI 22.1 to 24.5), respectively. Isolated chondrocytes from all groups were expanded by the following mean proportions after 28 days of culturing: group A ten times, group B 18 times, group C 106 times, and group D 154 times. This experiment demonstrated that it is possible to isolate viable chondrocytes from cryopreserved intact human articular cartilage which can then be successfully cultured.