Effect of bone morphogenetic protein-12 gene transfer on mesenchymal progenitor cells

Recombinant adenovirus mediated human bone morphogenetic protein-12 gene transfer induced tendon and cartilage-like tissue formation in vivo. The recombinant adenovirus with the human bone morphogenetic protein-12 gene was constructed, and mature human bone morphogenetic protein-12 expression mediated by adenovirus gene transfer was detected by specific antibody. Unlike bone morphogenetic protein-2 gene transfer, bone morphogenetic protein-12 gene transferred mesenchymal progenitor cell line C3H 10T1/2 showed no change of alkaline phosphatase activity, which is the mark of cell differentiation into osteoblastic phenotype. Injection of bone morphogenetic protein-12 gene transferred C3H 10T1/2 cells into nude mice thigh muscles induced tendon and cartilage-like tissue formation. The results indicate bone morphogenetic protein-12 has different effects on mesenchymal progenitor cell differentiation, and it may influence the cell differentiation into a nonosteoblast lineage.

Effects of physisorption of xenon on the thermal conductivity of resorcinol-formaldehyde aerogels

The effects of adsorption of xenon to the thermal conductivity of a resorcinol-formaldehyde aerogel were investigated in a temperature range from 20 to 120 K. It was found that at temperatures below 75 K, the adsorbed xenon has little effect on the thermal conductivity. Rapid rises of the thermal conductivity develop at temperatures around 75-80 K with magnitudes roughly proportional to the amount of xenon adsorbed. The effect is explained as due to adsorbed xenon atoms that enhance the neck connection between aerogel particles.

Expression of alpha-1 proteinase inhibitor in human islet microvascular endothelial cells

There is a microcirculation system within the islets of Langerhans. However, little is known about the phenotypic and functional characterization of islet microvascular endothelial cells (MVEC). In this study, we purified MVEC from human pancreatic islets by using Ulex europaeus (Sigma, St. Louis, MO) agglutinin-1 (UEA-1)-coated dynabeads (Dynal A.S., Oslo, Norway). These purified human islet MVEC (HI-MVEC) express von Willebrand factor, take up high levels of acetylated LDL, and upregulate endothelial cell leukocyte adhesion molecule 1 in response to tumor necrosis factor-alpha. Ultrastructure examination shows the presence of microvilli and fenestrations on the cell surface, Weibel-Palade bodies in the cytoplasm, and tight junctions between cells. Furthermore, we show that vascular endothelial cell growth factor contributes to the formation of surface fenestrations on cultured HI-MVEC. After purification, HI-MVEC exhibit a very low proliferation capacity and are strongly resistant to trypsin, compared with other original MVEC. We also demonstrate that alpha-1 proteinase inhibitor (Api) is expressed on HI-MVEC and specifically located at the area of cell-cell junctions. By reverse transcription-polymerase chain reaction, a significant messenger RNA band of Api was found only in HI-MVEC, but not in other organ-derived MVEC, indicating that expression of Api is islet MVEC specific. Antibodies to Api significantly reversed the resistance to trypsin and promoted proliferation of HI-MVEC, suggesting that these specific functional characteristics of HI-MVEC are related to the expression of Api. These results indicate that HI-MVEC exhibit some specific morphological and functional characteristics that differ from MVEC derived from other organs.

Congenital acute megakaryoblastic leukemia (M7) with chromosomal t(1;22)(p13;q13) translocation in a set of identical twins

Chromosomal translocations at t(1;22)(p13;q13) have been reported to occur in a number of infants with acute megakaryoblastic leukemia. A set of female twins with acute megakaryoblastic leukemia are reported with this unique translocation of 1p13 to 22q13. The twins presented at 2 months of age with fever and poor feeding and subsequently developed progressive hepatosplenomegaly. One twin died before treatment could be started; the other became septicemic 5 days after initiation of chemotherapy and eventually died.

Interferon-beta inhibits activated leukocyte migration through human brain microvascular endothelial cell monolayer

Perivascular leukocyte infiltration into the central nervous system is characteristic of multiple sclerosis (MS) pathology. Interferon-beta (IFN-beta) has shown efficacy in the treatment of patients with MS, but the relevant mechanisms remain incompletely understood. In this study the effects of IFN-beta on leukocyte transendothelial migration were investigated using cells relevant to MS pathogenesis, namely human brain microvascular endothelial cells (HB-MVEC). Activated, but not resting leukocytes exhibited a high transendothelial migration capacity. HB-MVEC prestimulated with tumor necrosis factor (TNF) and IFN-gamma significantly promoted leukocyte transendothelial migration. IFN-beta inhibited the activated leukocyte transendothelial migration on TNF/IFN-gamma-activated HB-MVEC in a dose-dependent manner. A matrix metalloproteinase (MMP) inhibitor and monoclonal antibodies to lymphocyte function antigen-1 (LFA-1) or intercellular adhesion molecule-1 (ICAM-1), but not to very late antigen-4 or to vascular cell adhesion molecule-1 significantly inhibited the transendothelial migration of stimulated leukocytes, suggesting that this phenomenon involves the LFA-1/ICAM-1 interaction and MMP. However IFN-beta did not interfere with the binding of leukocytes to HB-MVEC unless IFN-beta was preincubated with leukocytes or added to HB-MVEC at the time of stimulation. Furthermore IFN-beta did not modulate the expression of adhesion molecules on either stimulated leukocytes or activated HB-MVEC, but partially reduced TNF and interleukin-1 production from stimulated leukocytes during coculture with HB-MVEC. Interestingly, in the presence of IFN-beta, a significant down-regulation of MMP-9 release from stimulated leukocytes was found, especially for the activated form of MMP-9. These results indicate that inhibition of leukocyte transendothelial migration is an important mechanism accounting for the beneficial effects of IFN-beta in the treatment MS patients.

Enantioselective binding of an 11-cis-locked cyclopropyl retinal. The conformation of retinal in bovine rhodopsin

[formula: see text] The conformation of the retinal chromophore in rhodopsin is central for understanding the visual transduction process. The absolute twist around the 12-s bond of the chromophore in rhodopsin has been determined by studies with 11-cis-locked 11,12-cyclopropylretinal analogues (11S,12R)-2 and (11R,12S)-3, enantioselectively synthesized with the aid of an enzyme. The finding that enantiomer 2 binds to opsin while the other 3 does not defines the absolute sense of twist around the 12-s bond.

Clinical islet transplantation: a review

For decades, the inability of insulin therapy to physiologically control glycemia in type I diabetic patients has motivated the search for insulin-delivering grafts. Islet autotransplantation is such a therapeutic approach to prevent diabetes mellitus following a major pancreatectomy, whereas allotransplantation is generally prescribed for type I diabetic patients with a functional solid organ graft, or for patients awaiting one. As of today, over 150 patients have been autotransplanted world-wide, following total or subtotal pancreatectomy, permitting an insulin-independence in nearly 40% of patients. Furthermore, more than 350 islet allotransplantations have been performed. Recent results show improved metabolic control in over 50% of cases and insulin-independence in approximately 20%. This chapter presents a literature review including preliminary human islet transplantation data from the University of Geneva.

Decomplementation with cobra venom factor prolongs survival of xenografted islets in a rat to mouse model

Although the involvement of complement in hyperacute rejection of xenotransplants is well recognized, its role in rejection of devascularized xenografts, such as pancreatic islets, is not completely understood. In this study, we investigated whether complement participates in the immunopathology of xeno-islet transplantation in a concordant rat to mouse model. Rat pancreatic islets were implanted under the kidney capsule of normal and cobra venom factor (CVF)-decomplementized diabetic C57BL/6 mice. Graft survival was monitored by blood glucose levels. Deposition of IgM and C3 on grafted islets in vivo or on isolated islets in vitro (after incubation with normal and decomplementized mouse serum), as well as CD4- and CD8-positive leucocyte infiltration of grafts, was checked by immunohistochemistry. In addition, complement-mediated cytotoxicity on rat islet cells was evaluated by a 3-(4, 5-dimethythiazolyl)-2.5-diphenyl-2H-tetrazolium-bromide (MTT) assay. A significant C3 deposition was found on grafted islets from the first day after transplantation in vivo, as well as on isolated islets after incubation with mouse serum in vitro. By MTT assay, complement-mediated cytotoxicity for islet cells was found. Decomplementation by CVF decreased C3 deposition on either isolated or grafted islets, delayed CD4- and CD8-positive leucocyte infiltration, led to significant inhibition of complement-mediated cytotoxicity for islet cells, and prolonged graft survival (mean survival time 21.3 versus 8.5 days; P<0.01). Our results indicate that decomplementation can prolong the survival time of devascularized xenografts across concordant species. The deposition of complement on transplanted islets may contribute to xenograft rejection by direct cytotoxicity and by promoting leucocyte infiltration.

Mutagenesis studies of the FeSII protein of Azotobacter vinelandii: roles of histidine and lysine residues in the protection of nitrogenase from oxygen damage

The Azotobacter FeSII protein, also known as the Shethna protein, forms a protective complex with nitrogenase during periods when nitrogenase is exposed to oxygen. One possible mechanism for its action is an oxidation state-dependent conformational interaction with nitrogenase whereby the FeSII protein dissociates from the MoFe and Fe proteins of nitrogenase under reducing conditions. Herein we report the construction and characterization of five site-directed mutants of the FeSII protein (H12Q, H55Q, K14A, K15A, and the double mutant K14A/K15A) which were individually purified after being individually overexpressed in Escherichia coli. These mutant FeSII proteins maintain native-like assembly and orientation of the 2Fe-2S center on the basis of EPR and NMR spectroscopic characterization and their redox midpoint potentials, which are within 25 mV of that of the wild type protein. The abilities of the individual mutant proteins to protect nitrogenase were assessed by determining the remaining nitrogenase activities after adding each pure version back to extracts from an FeSII deletion strain, and then exposing the mixture to oxygen. In these assays, the H12Q mutant functioned as well as the wild type protein. However, mutation of His55, a few residues away from a cluster-liganding cysteine, results in much less efficient protection of nitrogenase. These results are consistent with pH titrations in both oxidation states, which show that His12 is insensitive to 2Fe-2S cluster oxidation state. His55's pK is weakly responsive to oxidation state, and the pK increase of 0. 16 pH unit upon 2Fe-2S cluster oxidation is indicative of ionization of another group between His55 and the 2Fe-2S cluster, which could modulate the FeSII protein's affinity for nitrogenase in a redox state-dependent manner. Both K14A and K15A mutant FeSII proteins partially lost their ability to protect nitrogenase, but the lysine double mutant lost almost all its protective ability. The nitrogenase component proteins in an Azotobacter strain bearing the double lysine mutation (in the chromosome) were degraded much more rapidly in vivo than those in the wild type strain under carbon substrate-limited conditions. These results indicate that the two lysines may have an important role in FeSII function, perhaps in the initial steps of recognizing the nitrogenase component proteins.

Interferon-induced guanylate binding protein-1 (GBP-1) mediates an antiviral effect against vesicular stomatitis virus and encephalomyocarditis virus

A cDNA encoding the human guanylate binding protein-1 (hGBP-1) was expressed in HeLa cells using a constitutive expression vector. Stably transfected clones expressing hGBP-1 exhibited resistance to the cytopathic effect mediated by both vesicular stomatitis virus (VSV) and encephalomyocarditis virus (EMCV) and produced less viral progeny than control cells following infection with these viruses. To study the role hGBP-1 plays in the IFN-mediated antiviral effect, cells were stably transfected with a construct expressing antisense RNA for hGBP-1. VSV infection of IFN-alpha-treated antisense RNA-expressing cells produced an amount of virus comparable to that produced in the parental cell line, while EMCV infection of the IFN-alpha-treated transfected cells and VSV and EMCV infection of the IFN-gamma-treated transfected cells produced far more virus than was produced in the parental cell line. These results demonstrate that GBP-1 mediates an antiviral effect against VSV and EMCV and plays a role in the IFN-mediated antiviral response against these viruses.

Effects of inhaled corticosteroid on bone turnover in children with bronchial asthma

Long-term usage of systemic steroids is associated with multiple side effects. One of the major morbidities is due to its effect on bone metabolism leading to bone loss and resulting in skeletal fractures. This study was conducted to determine the effects of inhaled steroids on bone mineral density (BMD) and biochemical bone markers. Twenty-four children with frequent episodic or mild persistent asthma who satisfied the clinical criteria for starting on inhaled corticosteroids (ICS) were enrolled into the study. The BMD scan was done using dual energy X-ray absorptiometry, prior to starting ICS therapy and 6 months later. Biochemical markers of bone metabolism, (i) serum osteocalcin as a bone formation marker, and (ii) urinary deoxypyridinoline (Upd) as a bone resorption marker, were taken prior to ICS treatment and at 2 monthly intervals. The biochemical markers were all taken in the morning. Twenty-four, age- and sex-matched children with mild episodic asthma, not requiring ICS, were used as controls for the BMD measurements. The BMD scan was done upon enrollment into the study and 6 months later. Twenty-four children on ICS and 24 controls completed the study. The subjects were on a mean dose of beclomethasone dipropionate (BDP) 0.4 mg/day. One subject needed a short course of Prednisolone in the early treatment period. None of the controls needed oral steroid therapy. One child in the control group sustained a greenstick fracture after an accidental fall. The mean rate of change of BMD was 1.8% +/- 12.3 in the subjects on BDP. This was lower than the 6.1% +/- 10.6 among the control subjects. However, this difference did not reach statistical significance (P = 0.16). There was a significant increase in serum osteocalcin level after 6 months of BDP treatment from 66.83 +/- 22.71 ng/mL to 81.61 +/- 24.66 ng/mL (P < 0.005). There was a decline in Upd from 36.2 +/- 47.1 nmol/mmol creatinine to 21.4 +/- 6.92 nmol/mmol creatinine. However, this did not reach statistical significance. There was no difference in the statural gain between the subjects on ICS and their controls. This study showed that 6 months of ICS therapy (mean dose 0.4 mg/day) had no significant adverse effect on bone metabolism in asthmatic children.

Gene therapy: adenovirus-mediated human bone morphogenetic protein-2 gene transfer induces mesenchymal progenitor cell proliferation and differentiation in vitro and bone formation in vivo

This study reports that recombinant adenovirus-mediated human bone morphogenetic protein-2 gene transfer can induce mesenchymal progenitor cell differentiation and bone formation. The recombinant adenovirus with the human bone morphogenetic protein-2 gene was constructed, and mature human bone morphogenetic protein-2 expression mediated by adenovirus gene transfer was detected by specific antibody. Under adenovirus-mediated bone morphogenetic-protein gene transfer, mesenchymal progenitor cell line C3H/10T 1/2 showed cell proliferation dependent on adenovirus bone morphogenetic-protein dose. The C3H/10T 1/2 cells transduced by adenovirus bone morphogenetic protein also exhibited differentiation to osteoblast phenotype, which indicates alkaline phosphatase activity. Injection of the C3H/10T 1/2 cells into the thigh muscles of nude mice led to ossicle development detectable on radiographs. Histological analysis indicated that the new ossicles that developed in the thigh muscles of the mice had different osseous components including bone trabeculae, bone marrow, and chondrified tissue. The results of this study demonstrate the potential for gene therapy by adenovirus-mediated bone morphogenetic-protein gene transfer.

The protective effects of traditional Chinese medicine prescription, han-dan-gan-le, on CCl4-induced liver fibrosis in rats

Han-Dan-Gan-Le, a Chinese medicine preparation composed of Salvia miltorrhiza, Radix paeoniae, Astragalus membranaceus, Stephania tetrandra, and dried leaves of Ginkgo biloba, has been used successfully to treat human liver fibrosis and cirrhosis for years. This study was designed to examine the mechanisms of the protection. Male Wistar rats were given CCl4 (1.2 ml/kg, 2 times/week), 20% fat diet, and 30% alcohol in drinking water (every other day) for 6 weeks. Han-Dan-Gan-Le (0.5 and 1.0 g/kg, p.o., daily for 6 weeks) was administered to rats simultaneously to examine the protective effects against CCl4-induced liver fibrosis. The experimentally-induced liver fibrosis and other morphological alterations were significantly ameliorated by Han-Dan-Gan-Le. Han-Dan-Gan-Le treatments decreased CCl4-induced hepatic collagen accumulation by more than 50%, and significantly increased urinary excretion of hydroxyproline. The CCl4-induced lipid peroxidation in liver and serum was ameliorated as a result of Han-Dan-Gan-Le treatment, possibly by restoring the activity of superoxide dismutase activity in liver and erythrocytes, In conclusion, Han-Dan-Gan-Le is effective in protecting against liver fibrosis. The mechanisms of the protection appear to be due to its antioxidant properties and the modulation of hepatic collagen metabolism.

Differential reactivity of brain microvascular endothelial cells to TNF reflects the genetic susceptibility to cerebral malaria

Upon infection with Plasmodium berghei ANKA (PbA), various inbred strains of mice exhibit different susceptibility to the development of cerebral malaria (CM). Tumor necrosis factor-alpha (TNF) and interferon-gamma (IFN-gamma) have been shown to be crucial mediators in the pathogenesis of this neurovascular complication. Brain microvascular endothelial cells (MVEC) represent an important target of both cytokines. In the present study, we show that brain MVEC purified from CM-susceptible (CM-S) CBA/J mice and CM-resistant (CM-R) BALB/c mice exhibit a different sensitivity to TNF. CBA/J brain MVEC displayed a higher capacity to produce IL-6 and to up-regulate intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in response to TNF than BALB/c brain MVEC. In contrast, no difference was found in the induction of E-selectin after TNF challenge. CM-S brain MVEC were also significantly more sensitive to TNF-induced lysis. This differential reactivity to TNF was further substantiated by comparing TNF receptor expression on CM-S and CM-R brain MVEC. Although the constitutive expression of TNF receptors was comparable on cells from the two origins, TNF induced an up-regulation of both p55 and p75 TNF receptors in CM-S, but not in CM-R brain MVEC. A similar regulation was found at the level of TNF receptor mRNA, but not for receptor shedding. Although a protein kinase C inhibitor blocked the response to TNF in both the brain MVEC, an inhibitor of protein kinase A selectively abolished the response to TNF in CM-R, but not CM-S brain MVEC, suggesting a differential protein kinase involvement in TNF-induced activation of CM-S and CM-R brain MVEC. These results indicate that brain MVEC purified from CM-S and CM-R mice exhibit distinctive sensitivity to TNF This difference may be partly due to a differential regulation of TNF receptors and via distinct protein kinase pathways.

Apoptosis as a mechanism of neuronal cell death following acute experimental spinal cord injury

The complex biochemical interactions following acute spinal cord injury have undergone considerable investigation recently. Progress has been made in discovering both primary and secondary injury cascades that combine to produce the ultimate neurologic insult. Traditionally, neuronal and supporting cell death following spinal cord injury have focused on necrotic death pathways resulting passively from the actual mechanical tissue damage and inflammatory processes which follow. However, the occurrence of programmed apoptotic cell death which is an actively mediated cellular process may occur following acute spinal cord injury and, if present, may play a role in the ultimate neurologic insult. In this study, we document a chronologically-specific course of apoptotic cell death by the TUNEL assay technique following an acute experimental spinal cord injury in the rat model. In this manner, apoptotic cell death following acute spinal cord injury may play a pivotal role in the secondary injury cascade which produces the ultimate neurologic insult and may allow potential for mediating neuronal survival via anti-apoptotic factors such as the protooncogene Bcl-2.

Induction of bone formation using a recombinant adenoviral vector carrying the human BMP-2 gene in a rabbit spinal fusion model

Bone marrow-derived mesenchymal stem cells are pluripotential cells that have the capacity to differentiate into an osteoprogenitor line. It has been demonstrated that BMP-2 can enhance this differentiation process. In an attempt to prolong the transforming effect of BMP-2, we used an adenoviral vector carrying the human BMP-2 gene to transduce marrow-derived mesenchymal stem cells of New Zealand white rabbits. Assays on tissue culture demonstrated that these cells indeed produced the BMP-2 protein. These transduced stem cells were then autologously reimplanted into the donor rabbits. The cells were placed in the intertransverse process area of five rabbits. In one out of the five rabbits, this resulted in the production of new bone which was demonstrable on both radiographic and histologic examination. We conclude that it is possible to successfully transduce mesenchymal stem cells with the gene for BMP-2 such that these cells will produce the BMP-2 protein in vitro. Further, the transduction results in transformation of these cells into an osteoprogenitor line capable of producing bone in vivo. These data suggest the feasibility of employing gene therapy using recombinant adenoviral vectors as a tool for enhancing spine fusion. Further work to improve the fidelity and longevity of the gene transfer is warranted.

Infections in acute lymphoblastic leukaemia

We did a retrospective study of all acute lymphoblastic leukaemia (ALL) patients on United Kingdom ALL protocol who were admitted for febrile neutropenia. The aim of the study was to document the types of infections and aetiological agents associated with febrile neutropenia and to document the factors affecting mortality. Over the 8 1/2-year period from 1986 to June 1995, there were 77 episodes in 32 children with a mean of 2.4 episodes. Morbidity due to infection was 61%; unknown causes of fever contributed 39%. Of the microbiologically documented infections, majority were Gram-negative bacteraemia. There were 7 deaths (22%) during the study period, 3 (9%) of which were due to overwhelming sepsis, with 4 contributed by the relapse status of the leukaemia. Mortality was increased by prolonged neutropenia, relapse of the leukaemia and invasive fungal infection.

In vivo Bcl-2 oncogene neuronal expression in the rat spinal cord

STUDY DESIGN

An acute mechanical rat spinal cord injury model was used to investigate in vivo Bcl-2 oncogene overexpression in neuronal tissue.

OBJECTIVES

To introduce the Bcl-2 oncogene in vivo by a recombinant adenovirus vector into rat spinal cord tissue, and to investigate any potential protective effect on neural tissue in the zone of injury in a rat spinal cord model.

SUMMARY OF BACKGROUND DATA

The Bcl-2 oncogene inhibits apoptotic and necrotic neural cell death in vitro by regulating an antioxidant pathway at sites of free radical generation. Thus, overexpression of the Bcl-2 oncogene may have a role in limiting the secondary injury cascade of spinal cord injury through its regulation of antioxidants.

METHODS

After confirmation of Bcl-2 gene expression in vitro and in vivo in the rat spinal cord, a weight-drop spinal cord injury model was performed on seven rats with prior Bcl-2 inoculation, and on seven rats with prior B-gal inoculation (controls).

RESULTS

In vivo Bcl-2 expression was documented by immunostaining. After spinal cord harvest, quantification of percentage preserved tissue at the spinal cord injury site suggested that Bcl-2 overexpression confers neuroprotection.

CONCLUSIONS

In vivo Bcl-2 oncogene overexpression was successfully induced in neuronal tissue. After Bcl-2 oncogene expression in the rat spinal cord, the zone of microscopic injury was diminished. Further investigation of the Bcl-2 oncogene for potentially enhancing neuronal survival after spinal cord injury appears indicated.

Inhibition of leukocyte adherence and transendothelial migration in cultured human liver vascular endothelial cells by prostaglandin E1

Primary graft dysfunction is a major complication of orthotopic liver transplantation, and hepatic ischemic reperfusion injury is considered to be its major determinant cause. Although oxygen free radicals play an important role, leukocytes, cytokines, and adhesion molecules also contribute to hepatic ischemic reperfusion injury. Prostaglandin E1 (PGE1) has been shown to protect against impairment and dysfunction of transplanted livers in various experimental models as well as in clinical liver transplantation. In this study, the role of PGE1 on leukocyte adherence and transendothelial migration was investigated in cultured human liver vascular endothelial cells (HLVEC). Our results indicated that stimulated, but not resting, leukocytes exhibited high adhesion and transmigration capacity. HLVEC incubated with tumor necrosis factor (TNF) promoted leukocyte adherence and transendothelial migration. PGE1 inhibited leukocyte adherence to HLVEC when it was preincubated with either HLVEC or leukocytes. Moreover, PGE1 also suppressed stimulated leukocyte transendothelial migration in a dose-dependent manner. The inhibitory activity of PGE1 was further investigated on both HLVEC and leukocytes with attention to adhesion molecules. On HLVEC, PGE1 down-regulated TNF-induced expression of endothelial cell leukocyte adhesion molecule 1 and vascular adhesion molecule 1, but not intercellular adhesion molecule 1. On leukocytes, PGE1 inhibited expression of CD11a/CD18 and membrane-bound TNF on PHA-stimulated leukocytes. PGE1 also suppressed TNF release from the stimulated leukocytes. These results indicated that inhibition of leukocyte adherence and transendothelial migration is one of the mechanisms by which PGE1 protects liver grafts.

Accidental ingestions in childhood

One-hundred and twelve cases of accidental poisoning were admitted over a 2-year study period (December 1990 to December 1992). Data was collected upon admission and patients were subsequently followed-up. Fifty-four percent of admission were boys. Majority of them were toddlers between the ages of 1 and 3 years. Thirty percent of accidental ingestions occurred during the school/public holidays. These occurred when the caretakers were preoccupied. Forty-nine percent of patients ingested oral medication; 16% ingested household liquids and the rest ingested other household products like cockroach tablets and thermometer mercury. The most commonly ingested medications were paracetamol, salicylate and bronchodilators, whilst chlorox, kerosene and detergents were the common household liquids ingested. The ability of the caregivers to quantitate the ingested product was poor. The mean hospital stay of the patients was 2.5 days. The majority of them were admitted for observation which did not require antidotes. Four cases were observed in the intensive care unit. There were no fatalities during the study period. Forty-four percent of the patients had samples taken for toxicology analysis, of which, less than half had positive results. All the patients were advised on the safety measures to look out for after admission. Less than 10% of cases had prior knowledge of such measures before the accidents occurred.

Glycogen biosynthesis via UDP-glucose in the ruminal bacterium Prevotella bryantii B1(4)

Prevotella bryantii is an important amylolytic bacterium in the rumen that produces considerable amounts of glycogen when it is grown on maltose. Radiolabel studies indicated that glucose-1-phosphate was converted to UDP-glucose, and this latter intermediate served as the immediate precursor for glycogen synthesis. High levels of UDP-glucose pyrophosphorylase activities (> 1,492 nmol/min/mg of protein) were detected in cells grown on maltose, cellobiose, glucose, or sucrose, and activity was greatly stimulated (by approximately 60-fold) by the addition of fructose-1,6-bis phosphate (half-maximal activation concentration was 240 microM). However, ADP-glucose pyrophosphorylase activity was not detected in any of the cultures. Glycogen synthase activity in maltose-grown cultures (48 nmol/min/mg of protein) was higher than that in cellobiose-, sucrose-, and glucose-grown cultures (< 26 nmol/min/mg of protein). This is the first report of a bacterium that exclusively uses UDP-glucose to synthesize glycogen. The elucidation of this unique glycogen biosynthesis pathway provides information necessary to further investigate the role of bacterial glycogen accumulation in rumen metabolism.

In vivo gene transfer and overexpression of focal adhesion kinase (pp125 FAK) mediated by recombinant adenovirus-induced tendon adhesion formation and epitenon cell change

Adhesion formation is a frequent complication of tendon injury repair: however, little is known about its mechanisms. The intracellular focal adhesion kinase (FAK)-related signaling pathway may be one of the mechanisms involved in the induction of tendon adhesions. The replication deficient adenovirus containing the FAK gene (pp125 FAK) was constructed and named Adv-Fak. By in vitro transductions with the recombinant virus, overexpression of the FAK protein was documented in transduced cultured primary tendon cells. By in vivo direct injection of Adv-FAK into the space between the tendon and tendon sheath of White Leghorn chickens, FAK gene transfer with overexpression of the FAK protein was detected by immunohistological staining. The morphology of these stained cells changed from the normal flat shape to cuboid. The group with overexpressed adenovirus-mediated FAK had significant adhesion formation, as seen by increased work of flexion (118.197 +/- 29.616), compared with the group with overexpressed adenovirus-mediated beta-galactosidase (67.507 +/- 36.066) (p < 0.0393) and the group with adenovirus-mediated FAK antisense gene transfer (60.357 +/- 48.562) (p < 0.0211). Histological examination of the samples from tendons with Adv-FAK showed fibers between the tendon and tendon sheath; there were no fibers in the cavities of samples of injured tendons infected with Adv-beta gal. Moreover, at the application site of the former tendons, a thick fiber layer without epitenon cells was built up on the outer surface, whereas a thin fiber layer with clear epitenon cells was observed in the tendons to which Adv-beta gal was applied. Our results show that overexpression of FAK can induce tendon adhesion formation in vivo. This indicates that FAK and the FAK-related signaling pathway may be involved in the process of tendon adhesion formation. Understanding the details of this process may help to prevent tendon adhesion and improve healing.