Co-culture of cord blood CD34(+) cells with human BM mesenchymal stromal cells enhances short-term engraftment of cord blood cells in NOD/SCID mice

BACKGROUND

The major challenge for cord blood transplantation (CBT) is higher rates of delayed and failed engraftment. In an attempt to broaden the application of CBT to more candidates, ex vivo expansion of hematopoietic stem/progenitor cells in CB is a major area of investigation. The purpose of this study was to employ human BM mesenchymal stromal cells (hBM-MSC) as the feeding-layer to expand CB cells ex vivo.

METHODS

In this study, hBM-MSC were isolated and characterized by morphologic, mmunophenotypic and RT-PCR analysis. The hBM-MSC at passage 3 were employed as the feeding-layer to expand CB CD34(+) cells in vivo in the presence of thrombopoietin, flt3/flk2 ligand, stem cell factor and G-CSF. The repopulating capacity of the ex vivo-expanded CB cells was also evaluated in a NOD/SCID mice transplant experiment.

RESULTS

After 1 or 2 weeks of in vitro expansion, hBM-MSC supported more increasing folds of CB in total nucleated cells, CD34(+) cells and colony-forming units (CFU) compared with CB without hBM-MSC. Furthermore, although NOD/SCID mice transplanted with CB cells expanded only in the presence of cytokines showed a higher percentage of human cell engraftment in BM than those with unexpanded CB CD34(+) cells, expanded CB cells co-cultured with hBM-MSC were revealed to enhance short-term engraftment further in recipient mice.

DISCUSSION

Our study suggests that hBM-MSC enhance in vitro expansion of CB CD34(+) cells and short-term engraftment of expanded CB cells in NOD/SCID mice, which may be valuable in a clinical setting.

Characterisation of insulin-resistant phenotype of cultured rat primary adipose cells

AIMS/HYPOTHESIS

We characterised insulin resistance, metabolic defects and endocrine dysfunction in cultured adipose cells and examined the autocrine or paracrine roles of cytokines/adipokines in the progression of insulin resistance.

MATERIALS AND METHODS

Rat primary adipose cells were prepared and cultured for 24 and 48 h. Insulin resistance and gene expression were examined by glucose uptake assay, cDNA microarray and real-time RT-PCR.

RESULTS

After 24 h in culture, the fold increase of insulin-stimulated glucose uptake in adipose cells was markedly reduced; after 48 h the response of the cells to insulin decreased. cDNA microarray analysis showed that the expression of 514 genes was altered in adipose cells after 24 h in culture. The dysregulated genes included those involved in the citric acid cycle and in fatty acid and pyruvate metabolism. Specifically, the following genes were all downregulated: genes encoding lipolytic and lipogenic enzymes; uncoupling protein 1 and 2 genes; peroxisome proliferator-activated receptor gamma, coactivator 1 alpha gene. This indicates that lipolytic and lipogenic activity, as well as mitochondria capacity decline in adipose cells cultured for 24 h. The mRNAs encoding 40 adipokines were also dysregulated in cultured cells. Strikingly, the dysregulated adipokines in cultured cells and in freshly isolated adipose cells from insulin-resistant Zucker fa/fa rats displayed a similar pattern with regard to protein functions. Also striking was the fact that progression of insulin resistance was promoted by the adipokines secreted from insulin-resistant adipose tissue or cells.

CONCLUSIONS/INTERPRETATION

Our data demonstrate that the impairment of metabolism and endocrine dysfunction in cultured adipose cells mimics the insulin resistance occurring in vivo. Cytokines and adipokines appear to play a critical role in the progression of insulin resistance in adipose cells.

RAPD analysis of jasmine rice-specific genomic structure

Total genomic DNA was extracted from 29 samples of rice seed, including jasmine rice Oryza sativa L. subsp indica 'KDML105', 'KDML105'-derived varieties, nonaromatic Thailand rice, and japonica rice. Polymorphism in RAPD profiles was analyzed to explore the genomic structure specific to jasmine rice. The degree of band sharing was used to evaluate genetic distance between varieties and to construct a phylogenetic tree. RD15, CNTLR85033, and CNT87040 were found to be closest to 'KDML105', which was consistent with the true relation among them. Four RAPD fragments that cooperatively distinguished jasmine rice from others were cloned and sequenced. PCR amplification using pairs of primers designed specifically further confirmed the credibility of the RAPD result. Comparison through Genbank revealed that a 454 bp RAPD band was similar to the first intron of a putative Cf2/Cf5 disease resistance gene and a 1,107 bp RAPD band similar to a wall-associated kinase (wak) gene sequence.

Surgical complications of Tenckhoff catheters used in continuous ambulatory peritoneal dialysis

INTRODUCTION

The objective of this study was to audit the early and late complications of open Tenckhoff catheter insertion under local anaesthesia in a single institution.

METHODS

A review was carried out on 164 insertions in 139 patients over a three-year period. All patient records were retrospectively analysed until the time of transfer to haemodialysis, death, or to current time if alive and receiving continuous ambulatory peritoneal dialysis (CAPD). Patient characteristics, operative factors, early and late complications were recorded.

RESULTS

Early complications were reported in 31 percent of catheter insertions, predominantly wound infections and catheter malfunctions. The factors that were significantly associated with early complications were diabetes mellitus, glomerulonephritis, ongoing sepsis, previous abdominal surgery and prolonged surgical time. Late complications were seen in 26 percent of catheter insertions, mainly CAPD peritonitis. Poor nutritional status had a significant negative impact on late complications. The overall median catheter survival time was 41.9 months (95 percent confidence interval, 25.8-58.0 months). In addition, no significant difference in catheter survival time was detected between those patients with and those without diabetes mellitus.

CONCLUSION

Tenckhoff catheter insertion for CAPD is a procedure associated with significant surgical morbidity. Patients with diabetes mellitus, glomerulonephritis and ongoing sepsis are at greater risk of early complications, and hence, must have their conditions stabilised or treated before surgery. In addition, prolonged surgical time and patients with previous abdominal surgery are at increased risk. The rate of complications may be improved by early consideration of patients with poor tolerance of local anaesthetic surgery or with previous abdominal surgery for laparoscopic insertion under general anaesthesia. To prevent late complications dominated by CAPD peritonitis, patients' nutritional status and care of the catheter should both be optimised.

Pregnancy outcomes from in-vitro fertilisation and intracytoplasmic sperm injection: a comparison

INTRODUCTION

The purpose of this study was to compare the obstetrical course of in-vitro fertilisation pregnancies with and without intracytoplasmic sperm injection, and to ascertain any difference in the outcome. Both singleton and multiple pregnancies were assessed individually in areas where they could confound results.

METHODS

This was a retrospective analysis of all successful in-vitro fertilisation pregnancies at the Singapore General Hospital during the period 1998-2003. A total of 271 pregnancies with and without intracytoplasmic sperm injection were evaluated. The details of the pregnancies were obtained from the Assisted Reproductive Technology Registry and Birth Defects Registry.

RESULTS

The obstetrical outcome was comparable between the two groups, in terms of the number of deliveries, biochemical and ectopic pregnancies. There was no significant difference in the miscarriage rate. The preterm rates for an intracytoplasmic injection pregnancy were two times higher than that reported in literature for both singletons and multiple pregnancies. The singleton intracytoplasmic sperm injection pregnancies were more likely to deliver preterm (17.5 percent, p-value is 0.041) compared to the ones without intracytoplasmic injection (5.7 percent). The average singleton birth weight was lower for the former (2.94 [+/-0.53] kg) than for the latter (3.19 [+/-0.48] kg, p-value is 0.0173). No definite conclusion could be reached regarding the differences in congenital abnormalities between the two groups.

CONCLUSION

The obstetrical course of an in-vitro fertilisation pregnancy with intracytoplasmic sperm injection pregnancy appears to be similar to one without intracytoplasmic sperm injection except for a slight increase in the preterm deliveries and a lower birth weight at delivery among the singletons.

Mortality after proximal hip fracture in the Singapore population

The aims were to prospectively assess the mortality risk following proximal hip fractures, identify factors predictive of increased mortality and to investigate the time trends in mortality with comparison to previous studies. Prospectively collected data from 68 consecutive patients who had been admitted to a regional hospital from May 2001 to September 2001 were reviewed. The mean age of the patients was 79.3 years old (range, 55-98) and 72.1% females. Patients were followed prospectively to determine the mortality risk associated with hip fracture over a two-year follow-up period. The acute in-hospital mortality rate at six months, one year and two years was 5.9% (4/68), 14.7% (10/68), 20.6% (14/68) and 25% (17/68) respectively. One-year and two-year mortality for those patients who were 80 or older was significantly higher than for other patients and the number of co-morbid illnesses also had significant effect. Cox regression was performed to determine the significant predictors for survival time. It was noted that patients 80 years or older were at higher risk of death compared with those less than 80 years as well as those with higher number of co-morbid illnesses. Our mortality rates have not declined in the past 10 years when compared with previous local studies. We conclude that for this group of patients studied, their mortality at one year and two years could be predicted by their age group and their number of co-morbid illnesses. (Hip International 2005; 15: 166-70).

Non-genomic action of estradiol and progesterone on cytosolic calcium concentrations in primary cultures of human granulosa-lutein cells

BACKGROUND

The present study examined whether the sex steroids, estradiol and progesterone, could alter cytoplasmic calcium concentrations ([Ca(2+)](cyt)) in human granulosa-lutein cells.

METHODS

Human granulosa cells were obtained at the time of oocyte retrieval for IVF and cultured for 3-7 days. Cells were loaded with Fura-2 AM and changes in [Ca(2+)](cyt) of single cells were studied using a dynamic digital Ca(2+) imaging system.

RESULTS

Both estradiol and progesterone stimulated elevations of [Ca(2+)](cyt) in Ca(2+)-containing medium within seconds of exposure of the granulosa-lutein cells to the steroid, but only estradiol caused an increase in [Ca(2+)](cyt) in Ca(2+)-free medium. Both ICI-182780 and RU 486 stimulated [Ca(2+)](cyt) increases and inhibited the effects of estradiol and progesterone, respectively. Tamoxifen also induced transient increases in [Ca(2+)](cyt) concentrations but inhibited the effects of both estradiol and progesterone. The inhibitory effects of tamoxifen, ICI-182780 and RU 4486 on [Ca(2+)](cyt) responses to estradiol and progesterone could be reversed with higher concentrations of estradiol and progesterone, respectively. The [Ca(2+)](cyt) effects induced with tamoxifen could not be eliminated by prior treatment with RU 486 or ICI-182780.

CONCLUSION

These results provide strong evidence that both estradiol and progesterone as well as the steroid antagonists, tamoxifen, RU 486 and ICI-182780, can act on human granulosa-lutein cells through a non-genomic mechanism.

Anti-cancer and pro-apoptotic effects of an herbal medicine and Saccharomyces cerevisiae product (CKBM) on human hepatocellular carcinoma HepG2 cells in vitro and in vivo

Hepatocellular carcinoma is a major health problem worldwide. Different treatment strategies have been developed to cope with this problem. Herbal medicine is now widely studied in both Eastern and Western countries. In this study, we used both in vitro and in vivo model to illustrate the anti-tumor effect of a product, CKBM, consisting of herbal medicine and specially processed Saccharomyces cerevisiae. Dose-dependent anti-proliferation effect was observed on in vitro growth of human hepatoma HepG2 cells after 48 hours incubation with CKBM. At the 50% inhibitory concentration (IC50) no significant toxic effect was observed on normal human fibroblasts Hs68 and human liver WRL-68 cells. The results of morphological changes, detection of DNA fragmentation, flow cytometric analysis and Western blot analysis indicated that this anti-tumor effect of CKBM was mediated via the process of apoptosis. In addition, HepG2 cells- bearing nude mice model was used for in vivo anti-tumor study. Our results showed that 14-day treatment with 0.8 ml daily dosage of CKBM could inhibit 54.1% of tumor growth. The plasma activities of enzymes specific for heart and liver, namely creatine kinase, lactate dehydrogenase, aspartate transaminase and alanine transaminase, remained at normal levels, indicated that CKBM did not produce toxicity to the host.

Immunomodulating Effects of CKBM on the Cytokine Production in Peripheral Blood Mononuclear Cells (PBMCs) from Healthy Volunteers

The current study investigated the immunomodulating effect of CKBM on cytokine induction in peripheral blood mononuclear cells (PBMCs) isolated from 20 healthy volunteers. Cytometric Bead Analysis (CBA) was used to study IL-2, IL-4, IL-6, IL-10, TNF-alpha and IFN-gamma. TNF-alpha and IL-6 were significantly increased in a CKBM dose- and time-dependent manner. Flow cytometry analysis showed an increased intracellular staining of IL-6 but not of TNF-alpha in CKBM treated PBMCs. In addition, MTT cell cytotoxicity assay showed that CKBM concentrations below 5% did not significantly affect the metabolic activities of PBMCs. The current study indicated that CKBM may modulate the immune response by inducing the secretions of TNF-alpha and IL-6, which are cytokine mediators of innate immunity and inflammation preparing or "priming" the body to combat diseases.

Nerve growth factor, brain-derived neurotrophic factor, and neurotrophin-3 are sorted to dense-core vesicles and released via the regulated pathway in primary rat cortical neurons

Neurotrophins (NTs) play an important role in the modulation of synaptic transmission and in morphological changes in synaptic structures. Although there is agreement that brain-derived neurotrophic factor (BDNF) is sorted to large dense-core vesicles (LDCVs) and released via the regulated secretory pathway, there has been some dispute regarding the mode of secretion of nerve growth factor (NGF) and neurotrophin-3 (NT-3), two structurally related members of the NT family. In this study, we examined the subcellular localization and release characteristics of NGF, BDNF, and NT-3 in adenovirus-infected primary cortical neurons. We found that all members of the NT family colocalized with markers for the endoplasmic reticulum and Golgi within cell bodies and in a punctate manner with a marker for LDCVs within processes. Moreover, their release was triggered by depolarization, indicating that NGF, BDNF, and NT-3 are released via the regulated secretory pathway. When neurons were coinfected with two separate adenoviruses coding for NGF or BDNF, both NTs showed almost complete vesicular colocalization within single cells, suggesting that different NTs might be packaged into shared vesicles. We also examined whether the two splice variants of NGF, the short and long precursors, differ in their release characteristics. We found that neurons infected with viruses coding for either splice variant released NGF in a regulated way. Overall, our study supports the notion that all members of the NT family undergo activity-dependent regulated release from neurons, enabling them to act as "synaptotrophins" on electrically active neurons.

Comparison of temporal filtering methods for dynamic contrast MRI myocardial perfusion studies

Dynamic contrast myocardial perfusion studies may benefit from methods that speed up the acquisition. Unaliasing by Fourier encoding the overlaps using the temporal dimension (UNFOLD), and a similar linear interpolation method have been shown to be effective at reducing the number of phase encodes needed for cardiac wall motion studies by using interleaved sampling and temporal filtering. Here such methods are evaluated in cardiac dynamic contrast studies, with particular regard to the effects of the choice of filter and the interframe motion. Four different filters were evaluated using a motion-free canine study. Full k-space was acquired and then downsampled to allow for a measure of truth. The different filters gave nearly equivalent images and quantitative flow estimates compared to full k-space. The effect of respiratory motion on these schemes was graphically depicted, and the performance of the four temporal filters was evaluated in seven human subjects with respiratory motion present. The four filters provided images of similar quality. However, none of the filters were effective at eliminating motion artifacts. Motion registration methods or motion-free acquisitions may be necessary to make these reduced FOV approaches clinically useful.

Determination of dextromethorphan and its metabolite dextrorphan in human urine by capillary gas chromatography without derivatization

A sensitive, simple and accurate method was developed for determination of dextromethorphan (DM) and dextrorphan (DT) in human urine by capillary gas chromatography without derivatization. After an oral dose of 30 mg DM, urine samples were collected and extracted, then analyzed on 0.22 mmx17 m HP-1 capillary column. DM and its metabolite DT were analyzed simultaneously with good separation. Docosane was used as the internal standard (I.S.). The detector used was flame ionization detector (FID). There was a linear relationship between peak area ratios of analytes to I.S. and concentration of analytes over the concentration range 0.37-7.38 micromol/l for DM and 0.39-77.8 micromol/l for DT. The recovery was 88.1 approximately 103.9% for DM and 86.7 approximately 96.8% for DT. The within-day and between-day coefficients of variation were less than 7.4 and 7.3% (RSD) for the assay of DM and DT in urine, respectively. The limits of detection (LOD) were 0.30 micromol/l for DM and 0.16 micromol/l for DT. The limits of quantitation (LOQ) were 0.37 micromol/l (RSD<6%) for DM and 0.39 micromol/l (RSD<7%) for DT. The method has been applied to determine the oxidative phenotypes of cytochrome P450 2D6 (CYP2D6) in a Chinese population with metabolic ratio of DM in human urine.

Neurotrophins are key mediators of the myelination program in the peripheral nervous system

Although knowledge of the functions of neurotrophins has advanced rapidly in recent years, studies concerning the involvement of neurotrophins in glial-neuronal interactions rarely extend further than their roles in supporting the survival and differentiation of neuronal cells. In this study endogenous brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) were identified in Schwann cell/dorsal root ganglia neuronal cocultures and shown to modulate the myelination program of the peripheral nervous system. The differential expression of BDNF and NT3 were examined and compared with the expression profiles of myelin proteins in the cocultures throughout the myelination process. BDNF levels correlated with active myelin formation, whereas NT3 expression was initially high and then down regulated throughout the proliferation and premyelination periods. Addition of exogenous BDNF enhanced myelination, whereas the removal of the endogenous BDNF by using the BDNF receptor TrkB-Fc fusion protein inhibited the formation of mature myelin internodes. Interestingly, exogenous NT3 significantly inhibited myelination, whereas the removal of the endogenous NT3 by using the NT3 receptor TrkC-Fc fusion protein resulted in an enhancement similar to that obtained with the addition of BDNF. In addition, in vivo studies were performed during the development of the mouse sciatic nerve. Subcutaneous injections of BDNF resulted in an enhancement of myelin formation in the sciatic nerve, whereas the removal of the endogenous BDNF dramatically inhibited myelination. Injections of NT3 inhibited myelin formation, and the removal of the endogenous NT3 enhanced myelination. These results demonstrate that BDNF and NT3 possess different modulatory roles in the myelination program of the peripheral nervous system and that their mechanisms of action are specific and highly regulated.

Anti-inflammatory effect and mechanism of proanthocyanidins from grape seeds

AIM

To investigate the anti-inflammatory effect and mechanism of proanthocyanidins (PA) from grape seeds.

METHODS

Croton oil-induced ear swelling in mice and carrageenan-induced hind paw edema in rats were prepared. The nitric oxide synthase (NOS) activity was measured by NADPH-diaphoras stain assay, nitric oxide (NO) content by Griess diazotization assay, N-acetyl-beta- D-glucosaminidase (beta-NAG) activity by spectrophotography, malondialdehyde (MDA) content by thiobarbituric acid (TBA) fluorescence technique, and IL-1beta, TNFalpha, and PGE2 content by radioimmunoassay (RIA).

RESULTS

PA 10-40 mg/kg ip inhibited carrageenan-induced paw edema in rats and croton oil-induced ear swelling in mice in a dose-dependent manner. PA 10 mg/kg reduced MDA content in inflamed paws, inhibited beta-NAG and NOS activity, and lowered the content of NO, IL-1beta, TNFalpha, and PGE2 in exudate from edema paws of rats induced by carrageenan. The inhibitory effect of PA on all above indices was more evident than that of dexamethasone 2 mg/kg.

CONCLUSION

PA has anti-inflammatory effect on experimental inflammation in rats and mice. Its mechanisms of anti-inflammatory action are relevant to oxygen free radical scavenging, anti-lipid peroxidation, and inhibition of the formation of inflammatory cytokines.

[Clinical observation on small doses Tripterygium wilfordii polyglycoside combined with methotrexate in treating rheumatoid arthritis]

OBJECTIVE

To observe the effect and adverse reaction of small doses Tripterygium wilfordii polyglycoside (TWP) combined with methotrexate (MT) in treating rheumatoid arthritis (RA).

METHODS

Seventy RA patients were randomly divided into two groups, the control group (35 patients) and the TWP combined MT Group (TWPM group). Both of them were continued to use the non-steroidal anti-inflammatory drugs. The control group took MT 15 mg orally, once every week; the TWPM group took TWP 10 mg orally, 3 times a day, and MT 7.5 mg orally once every week. The clinical effect and adverse reaction after treatment were evaluated.

RESULTS

The markedly effective rate in the control group and the TWPM group was 28.6% and 34.3% respectively, with no significant difference (P > 0.05). Data of symptoms and signs, erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) were determined respectively with significant difference (P < 0.01). The rate of adverse reaction was 20 cases-times in the control group and 8 cases-times in the TWPM group.

CONCLUSION

MT combined small doses of TWP in treating RA has better effect and less adverse reactions than un-combined MT.

Recent developments on ketolides and macrolides

Recent semi-synthetic studies of erythromycin A culminated in the discovery of two ketolide drug candidates, HMR-3647 and ABT-773, for the treatment of community-acquired bacterial infections caused by both macrolide- and beta-lactam-susceptible and -resistant S. pneumoniae, gram negative bacteria, and intracellular atypical pathogens. The discovery of ketolides has rekindled interest in macrolides, and recent efforts have also led to a novel class of 4''-carbamates with activity against macrolide-resistant organisms. This review is an account of recent developments on ketolides and macrolides in terms of both chemistry and antibacterial activity.

Effects of recombinant human basic fibroblast growth factor on restenosis after arterial endothelial injury in rats

AIM

To study the preventive effect of recombinant human basic fibroblast growth factor (rh-bFGF) on restenosis after percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Sixty male Wistar rats were randomly divided into sham operation group, intima injured group, and intima injured plus rh-bFGF treated group. Rat carotid arteries were injured using a balloon catheter except sham operation group. The rats of rh-bFGF treated group were injected im rh-bFGF 10 kU . kg-1 . d-1 after intima was injured. Ten rats in each group were killed on d 7 and d 14 after injury, respectively. [3H]Thymidine incorporation assay and pathological examination were carried out to each vessel.

RESULTS

(1) Seven days after injury, the average intimal thickness in sham operation group, intima injured group, and rh-bFGF treated group was (7 +/- 1), (32 +/- 11), and (17 +/- 3) micron; average intimal area was (384 +/- 145), (1530 +/- 817), and (586 +/- 185) micron2; the numbers of smooth muscle cells in neointima per transect were 0 +/- 0, 146 +/- 18, and 105 +/- 26; the ratio of the collagen area to intimal area plus medial area were 0.29 +/- 0.09, 0.7 +/- 0.3, and 0.30 +/- 0.14; [3H]thymidine incorporation were (17 +/- 6), (62 +/- 23), (20 +/- 8) kBq/g tissue, respectively. (2) Fourteen days after injury, the average intimal thickness of sham operation group, intima injured group, and rh-bFGF treated group was (8 +/- 1), (41 +/- 9), and (20 +/- 3) micron; average intimal area was (391 +/- 134), (1761 +/- 337), and (731 +/- 124) micron2; the numbers of smooth muscle cells in neointima per transect were 0 +/- 0, 145 +/- 9, and 102 +/- 6; the ratio of collagen area to intimal area plus medial area were 0.28 +/- 0.14, 0.59 +/- 0.21, and 0.38 +/- 0.03; [3H]thymidine incorporation was (15 +/- 4), (57 +/- 11), and (22 +/- 6) kBq/g tissue, respectively.

CONCLUSION

Large dosage of rh-bFGF inhibits neointimal hyperplasia and reduces restenosis after balloon injury.

Correlation of acoustic velocity of synovial fluid with markers of inflammation in arthritic patients

Analysis of synovial fluid is important in the evaluation and treatment of arthritic conditions. This study measured the acoustic velocity of synovial fluids in patients with degenerative joint diseases, crystal arthropathy, and other inflammatory arthropathies using the ultrasonic pulse-echo method. The measured acoustic velocities of these bio-fluids were then correlated with clinical parameters including the synovial white blood cell count (WBC), clarity, viscosity, string test, erythrocyte sedimentation rate (ESR), and serum C-reactive protein (CRP). Results showed that the acoustic velocities were correlated with ESR (p = 0.0016) and CRP (p = 0.0001). The mean acoustic velocity of inflammatory synovial fluids, defined as synovial fluids with WBCs of more than 2000/mm3, was greater than that of synovial fluids with WBCs of less than 2000/mm3 (1550 +/- 4.5 m/s vs 1544 +/- 1.5 m/s, p = 0.007). This study demonstrated that the acoustic velocity of synovial fluid correlates well with severity of inflammation. These findings suggest that measurement of acoustic velocity may be useful in the clinical evaluation and management of arthritic conditions.

Macrophage accumulation associated with rat cardiac allograft rejection detected by magnetic resonance imaging with ultrasmall superparamagnetic iron oxide particles

BACKGROUND

Acute cardiac allograft rejection continues to be the cause of graft loss and contributes to the morbidity and mortality after cardiac transplantation. In this study, we report a new method for detecting organ rejection in transplantation with an MR-based technique using dextran-coated ultrasmall superparamagnetic iron oxide (USPIO) particles. These particles ( approximately 27 nm in diameter) are known to shorten relaxation times in MRI experiments.

METHODS AND RESULTS

A new rat model of heterotopic heart and lung transplantation has been developed for MRI experiments. Allotransplantations (DA-->BN) were performed (n=8), with syngeneic transplantations (BN-->BN) serving as controls (n=8). MR images were obtained with a gradient echo method. At postoperative day 7, allotransplants developed moderate rejection as determined histopathologically. A significant reduction in MR signal intensity was observed after USPIO injection into rats with allotransplanted hearts. Syngeneic transplants showed no differences in MR signal intensity before and after USPIO injections. After injection of USPIO particles at postoperative day 6, a group of allotransplanted rats was treated with cyclosporin A (3 mg/kg). Animals treated with cyclosporin A for 7 days showed no reduction in MR signal intensity after USPIO reinjection at day 14, whereas animals treated for 4 days showed a significant decrease in MR signal intensity in the transplanted hearts indicative of acute graft rejection. Pathological analysis of these animals revealed that dextran-coated USPIO particles were taken up by the infiltrating macrophages that accumulated within the rejecting cardiac graft.

CONCLUSIONS

This MRI method offers promise as a noninvasive method for detecting transplant allograft rejection.

Angiotensin-converting enzyme inhibitor preserves p21 and endothelial nitric oxide synthase expression in monocrotaline-induced pulmonary arterial hypertension in rats

BACKGROUND

Pulmonary arterial hypertension (PAH) is associated with structural changes in the pulmonary vasculature characterized by the proliferation of cellular components of the vessels. ACE inhibitor (ACEI) may have beneficial effects in treating PAH, but its precise mechanism of action in the remodeling process is unclear. p21 is a cyclin-dependent kinase inhibitor that may have a protective role in this process by inhibiting cellular proliferation. Endothelial nitric oxide synthase (eNOS) has also been shown to be protective by its vasodilatory effect. Therefore, we investigated whether expression of p21 and eNOS was modulated by ACEI treatment in a rat model.

METHODS AND RESULTS

Monocrotaline (MCT) was administered to 2 groups of Sprague-Dawley rats fed a high-cholesterol diet, ie, one group received MCT concomitantly with enalapril treatment (MCT(+)/ACEI(+) rats), and the other group did not receive enalapril (MCT(+)/ACEI(-) rats). After 5 weeks, MRI showed right ventricular hypertrophy in MCT(+)/ACEI(-) rats. MCT(+)/ACEI(+) rats showed a preserved right ventricular morphology. Isolated pulmonary perfusion studies showed that ACEI significantly upregulated NO production, as measured by nitrite levels. Addition of N-methyl-D-glucamine dithiocarbamate-Fe solution, an NO-trapping agent, reversed the basal vasodilatory effect of ACEI in the pulmonary vasculature. Immunoblot analysis showed decreased p21 and eNOS expression in the lung in MCT(+)/ACEI(-) rats, whereas their expression was preserved with enalapril treatment.

CONCLUSIONS

ACEI suppresses the development of MCT-induced PAH in rats. The mechanism of action might involve the preservation of p21 and eNOS expression. Both p21 and endothelium-derived NO appear to have protective roles in the development of PAH.

Enhanced susceptibility to pulmonary infection with Burkholderia cepacia in Cftr(-/-) mice

Progressive pulmonary infection is the dominant clinical feature of cystic fibrosis (CF), but the molecular basis for this susceptibility remains incompletely understood. To study this problem, we developed a model of chronic pneumonia by repeated instillation of a clinical isolate of Burkholderia cepacia (genomovar III, ET12 strain), an opportunistic gram-negative bacterium, from a case of CF into the lungs of Cftr (m1unc-/-) (Cftr(-/-)) and congenic Cftr(+/+) controls. Nine days after the last instillation, the CF transmembrane regulator knockout mice showed persistence of viable bacteria with chronic severe bronchopneumonia while wild-type mice remained healthy. The histopathological changes in the lungs of the susceptible Cftr(-/-) mice were characterized by infiltration of a mixed inflammatory-cell population into the peribronchiolar and perivascular spaces, Clara cell hyperplasia, mucus hypersecretion in airways, and exudation into alveolar airspaces by a mixed population of macrophages and neutrophils. An increased proportion of neutrophils was observed in bronchoalveolar lavage fluid from the Cftr(-/-) mice, which, despite an increased bacterial load, demonstrated minimal evidence of activation. Alveolar macrophages from Cftr(-/-) mice also demonstrated suboptimal activation. These observations suggest that the pulmonary host defenses are compromised in lungs from animals with CF, as manifested by increased susceptibility to bacterial infection and lung injury. This murine model of chronic pneumonia thus reflects, in part, the situation in human patients and may help elucidate the mechanisms leading to defective host defense in CF.

Adult isolated hypoplasia of left pulmonary artery with exertional angina and abnormal exercise stress test: a case report and treatment implication

Pulmonary artery hypoplasia, either congenital or acquired, is a rare abnormality seen in adults. We reported the first case of adult, isolated, left pulmonary artery hypoplasia, with exertional angina and prominent ST depression in exercise stress test, that seemed to be caused by exertional hypoxemia. Several vasodilators, including nitroglycerin, prostaglandin E1, and nifedipine, were administered individually, each with subsequent hemodynamic monitoring, pulse oximetric monitoring, and exercise test. Vasodilator administrations reduced pulmonary vascular resistance (baseline, 599; vasodilators, 306, 211, and 284 dyne x sec x m2/cm5, respectively) and attenuated ST depression (by 52, 72, and 27%, respectively) but without an immediate benefit on exercise tolerance. All vasodilators except nifedipine ameliorated exertional hypoxemia (expressed by arterial oxygen saturation during peak exercise, baseline, 69%; vasodilators, 85, 78, and 65%, respectively). Additional oxygen supply after nitroglycerin administration further benefited exertional hypoxemia (arterial oxygen saturation, 96%) and exercise ST depression (attenuated by 82%).

Effect of recombinant human basic fibroblast growth factor on acute inflammation in mice and rats

AIM

To investigate the anti-inflammatory effects of recombinant human basic fibroblast growth factor (rh-bFGF).

METHODS

Several inflammation models such as croton oil-induced ear swelling, carrageenan-induced hind paw edema, and acute peritonitis in rats or mice were prepared. Superoxide dismutase (SOD) activity was measured by hydroxyamine method, nitric oxide (NO) concentration by Griess reaction assay, nitric oxide synthase (NOS) activity by NADPH-diaphoras stain assay, N-acetyl-beta- D-glucosaminidase (NAG) activity by colorimetry, prostaglandin E2 (PGE2) production by radioimmunoassay (RIA), malondialdehyde (MDA) content by thiobarbituric acid (TBA) fluorescence technique, and protein content by Coomassie brilliant blue method in peritoneal exudate in rats.

RESULTS

Recombinant human bFGF 2, 4 kU/kg im inhibited croton oil-induced ear swelling and carrageenan-induced paw edema in mice. In addition, rh-bFGF 2, 4 kU/kg im reduced neutrophil counts in the rat peritoneal exudate, and lessened protein content in peritoneal exudate in rats and mice. In the rat peritonitis induced by carrageenan, rh-bFGF 4 kU/kg decreased the MDA and NO levels, inhibited the NOS activity, augmented the SOD activity, and lowered the production of PGE(2) in exudate. However, rh-bFGF had no effect on NAG content.

CONCLUSION

Recombinant human bFGF has an anti-inflammatory effect and its mechanisms are related to the inhibition of NOS activity, reduction of NO, MDA, and PGE(2) content, and increase of SOD activity.

On-column amperometric detection of ofloxacin and pasiniazid in urine by capillary electrophoresis with an improved fractured joint and small detection cell

An improved high-voltage electric field isolating joint and small detection cell have been carefully designed and fabricated. The joint possesses short steady time, high electric conductance efficiency and high performance. The cell is convenient to install and remove the capillaries with and without the joint, as well as to fix, adjust and insert the microelectrode into the detection capillary. Using the joint and the cell, an analytical method for determination of ofloxacin (Oflx) and pasiniazid (Ipa) in urine by capillary electrophoresis with on-column amperometric detection was developed. The calibration lines were linear in the range of 10-100 mg l-1 of Oflx and 1.0-50 mg l-1 of Ipa, respectively. The detection limits were 8.5 mg l-1 of Oflx and 0.80 mg l-1 of Ipa. Their recovery ranged from 101 to 104%. The accuracy and intra-day and inter-day reproducibility of Oflx and Ipa were determined with satisfactory results. This method was successfully used for determining Oflx and Ipa in human urine.