Implantation of BM mesenchymal stem cells into injured spinal cord elicits de novo neurogenesis and functional recovery: evidence from a study in rhesus monkeys.

BACKGROUND: Transplantation of mesenchymal stem cells (MSC) in rodent models has proved to be an effective therapeutic approach for spinal cord injury (SCI). However, further studies in primate models are still needed before clinical application of MSC to patients. METHODS: MSC were isolated from rhesus monkey BM and induced ex vivo to differentiate into neural lineage cells. Induced cells were labeled with Hoechst 33342 and injected into the injured sites of rhesus SCI models. Function of the injured spinal cord was assessed using Tarlov behavior assessment, sensory responses and electrophysiologic tests of cortical somatosensory-evoked potential (CSEP) and motor-evoked potential (MEP). In vivo differentiation of the implanted cells was demonstrated by the presence of neural cell markers in Hoechst 33342-labeled cells. The re-establishment of the axonal pathway was demonstrated using a true blue (TB) chloride retrograde tracing study. RESULTS: Monkeys achieved Tarlov grades 2-3 and nearly normal sensory responses 3 months after cell transplantation. Both CSEP and MEP showed recovery features. The presence of the neural cell markers neurofilament (NF), neuro-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) was observed in approximately 10% of Hoechst 33342-labeled cells. TB, originally injected at the caudal side of injured sites, was traceable in the rostral thoracic spinal cord, red nucleus and sensory motor cortex. DISCUSSION: Our results suggest that the implantation of MSC-derived cells elicits de novo neurogenesis and functional recovery in a non-human primate SCI model and should harness the clinical application of BM MSC in SCI patients.

Zinc sulphate solution enema decreases inflammation in experimental colitis in rats.

BACKGROUND: It has been reported that zinc sulphate contributes an anti-inflammatory action in many animal models; however, the impact of zinc in colitis remains unclear. The aim of the present study was to examine the role of zinc sulphate in experimental colitis. METHODS: Colitis was induced by 2,4,6-trinitrobenzenesulphonic acid (TNB) in rats. Beginning at the first day of TNB colitis, the rats were treated with a zinc sulphate enema once daily for 6 days. The rats were examined 8 days later. RESULTS: The TNB induced severe colitis as evidenced by increased mucosal lesion area, mucosal myeloperoxidase (MPO) activity and prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels. Six days after the application of the zinc sulphate enema, the mucosal lesion area, MPO activity, PGE2 and LTB4 levels all decreased significantly. Mucosal superoxide dismutase activity remained unchanged after zinc treatments. CONCLUSIONS: Our data suggest that zinc sulphate enemas have an anti-inflammatory action on experimental colitis.

[Protective effect of dl-3-n-butylphthalide on ischemic neurological damage and abnormal behavior in rats subjected to focal ischemia].

dl-3-n-Butylphthalide (NBP) was known to have improving effect on brain energy metabolism after ischemia insult. The purpose of this study is to determine if the drug has protective action against ischemic neuronal damage. In the present study, the effect of NBP on cerebral infarction and neurological deficits after middle cerebral artery occlusion (MCAO) in rats was investigated. Focal cerebral ischemia was produced by permanent occlusion of the proximal portion of the right middle cerebral artery (MCA) according to the technique of Tamura. The infarct area was measured by 2,3,5-triphenyltetrazolium chloride (TTC) staining technique. The extent of neurological deficits was evaluated by the method of Bederson. The histological changes in neuronal change after MCAO in rats were also studied. The results indicate that the infarct area and the score of neurological deficits after MCAO were reduced significantly following intraperitoneal pretreatment or pre- and post-treatment with NBP 20 mg . kg-1. The treatment with NBP 10 or 20 mg . kg-1(i.p.), or 20,40 or 80 mg . kg-1 (po) 15 min and even 2 h (20 mg . kg-1, i.p.) after MCAO also markedly reduced the infarct area and the score of neurological deficits. However, no effect was found when NBP (20 mg . kg-1) was injected intraperitoneally 4 h after MCAO. MK-801 (0.5 mg . kg-1, i.p.), a non-competitive antagonist of NMDA receptor, significantly reduced the size of infarction and the score of neurological deficits in rats subjected to MCAO. The potency of NBP in reducing the infarct area and neurological deficits was found to be quite similar to that of MK-801 (0.5 mg . kg-1, i.p.). No neuroprotective effect of nimodipine (1.0 mg . kg-1, sc) was found. Generally, the potency of NBP in protecting rats from ischemic neurological damage is equal to that of MK-801 and is more powerful than that of Nimodipine. Side effects of NBP in behavior was not found. Therefore, NBP seems to be a hopeful drug for the treatment of stroke.

Felodipine- and ethanol-induced gastric mucosal damage in rats.

Calcium channel blockers like verapamil have been shown to potentiate ethanol-induced gastric mucosal damage. However, the exact mechanism for this adverse drug interaction is still unknown. We used felodipine to study the ulcerogenic mechanisms of calcium channel blockers and the pathogenesis of ethanol-induced ulceration. The experiment was conducted in an ex vivo gastric chamber prepared in anesthetized animals. Felodipine (0.25, 0.5, 1.0, or 2.0 mg/kg s.c.) dose-dependently reduced the systemic blood pressure which was accompanied by a decrease in gastric mucosal blood flow (GMBF), with an insignificant change in heart rate. Ethanol lowered the GMBF and produced gastric mucosal lesions, and these actions were potentiated by felodipine. Preincubation with calcium gluconate but not the sodium salt attenuated the adverse effects of ethanol on GMBF and lesion formation; it also significantly prevented the gastric effects of felodipine but not the decrease of the systemic blood pressure. It is concluded that felodipine aggravates ethanol ulceration through a depressive action on the GMBF. These actions were attenuated by the supplementation with calcium ions in the gastric mucosa. Therefore, maintenance of calcium homeostasis in the gastric wall could play a significant role in the prevention of ethanol ulceration in rats.

Molecular characterization and chromosomal localization of DRT (EPHT3): a developmentally regulated human protein-tyrosine kinase gene of the EPH family.

By screening a human fetal brain cDNA expression library using a monoclonal antiphosphotyrosine antibody and by 5' RACE procedures, we have isolated overlapping cDNAs encoding a receptor-type tyrosine kinase belonging to the EPH family, DRT (Developmentally Regulated EPH-related Tyrosine kinase gene). The DRT gene is expressed in three different size transcripts (i.e. 4, 5 and 11 kb). DRT transcripts are expressed in human brain and several other tissues, including heart, lung, kidney, placenta, pancreas, liver and skeletal muscle, but the 11 kb DRT transcript is preferentially expressed in fetal brain. Steady-state levels of DRT mRNA in several tissues, including brain, heart, lung and kidney, are greater in the midterm fetus than those in the adult. DRT transcripts are detectable at low levels in a human teratocarcinoma cell line (NTera-2), but its expression is greatly increased after the NTera-2 cells are induced to become postmitotic neurons (NTera-2N) by retinoic acid treatment. These data suggest that DRT plays a part in human neurogenesis. A large number of tumor cell lines derived from neuroectoderm express DRT transcripts, including 12 neuroblastomas, two medulloblastomas, one primitive neuroectodermal tumor and six small cell lung carcinomas (SCLC). Interestingly, several neuroblastoma cell lines with 1p deletion and one SCLC cell line express DRT transcripts of aberrant size (i.e. 3, 6 and 8 kb) in addition to those found in normal tissues. We mapped the DRT gene to human chromosome 1p35-1p36.1 by PCR screening of human-rodent somatic cell hybrid panels and by fluorescence in situ hybridization. As the distal end of chromosome 1p is often deleted in neuroblastomas and altered in some cases in SCLCs, these chromosomal abnormalities may have resulted in the generation of aberrant size transcripts. Thus, the DRT gene may play a part in neuroblastoma and SCLC tumorigenesis.

Nonfluoroscopic reduction of intussusception by air enema.

Intussusception is a common pediatric condition in China. Hydrostatic reduction with barium sulfate or pneumatic reduction using air and fluoroscopy has become the standard method in most centers throughout the world. To avoid radiation exposure, reduction without fluoroscopic confirmation was studied. Between 1981 and 1985 a total of 224 children were diagnosed and treated for intussusception. The diagnosis was made correctly on clinical grounds in 184 cases; in 40 cases ultrasonography confirmed the clinical diagnosis. Pressurized air reduction was successful in 217 patients (96.9%); seven patients required operative reduction. Ultrasonograms of the abdomen supported the diagnosis in 40 patients and confirmed subsequent reduction. This experience demonstrates that childhood intussusception can be reduced using pneumatic pressure without exposing the patient to ionizing radiation.

Cloning and chromosomal localization of the human TRK-B tyrosine kinase receptor gene (NTRK2).

There is increasing evidence that neutrophins and their receptors play an important role in regulating development of both the central and the peripheral nervous systems. Human TRK-A (NTRK1) and TRK-C (NTRK3) have been cloned and sequenced, but only a truncated form of human TRK-B has been published. Therefore, we isolated complementary DNAs spanning the entire coding region of both human full-length and truncated forms of TRK-B from human brain cDNA libraries. Human full-length TRK-B codes for a protein of 822 amino acid residues. The putative mature peptide sequence is 49% homologous to human TRK-A and 55% to full-length human TRK-C, with 40% amino acid identify among TRK-A, -B, and -C. Nine of 13 cysteine residues, 4 of 12N-glycosylation sites in the extracellular domain, and 10 of 13 tyrosine residues in the intracellular domain are conserved among human TRK-A, -B, and -C. There is a cluster of 10 serine residues in the juxtamembrane region of TRK-B that is absent in TRK-A. Two major sizes of TRK-B transcripts were expressed in human brain. Northern blot analysis using probes specific for the extracellular or the tyrosine kinase domain revealed that the 9.5-kb band encodes the full-length TRK-B mRNA and the 8.0-kb band encodes the truncated form of TRK-B mRNA. By fluorescence in situ hybridization and somatic cell hybrid mapping, the human TRK-B gene was localized to chromosome 9q22.1.

Growth promoting effect of zinc supplementation in infants of high-risk pregnancies.

This study was made to determine whether zinc deficiency is one of the factors involved in growth retardation of infants of high-risk pregnancies. The high risk factors were hypertension of pregnancy, diabetes mellitus, congenital heart disease, chronic nephritis, rheumatic heart disease and hyperthyroidism. 102 neonatal infants were divided into 3 groups: breast fed group, 37 cases; test group, 32 cases formula-fed with supplementary zinc 1.14-2.28 mg/kg/d; and control group, 33 cases formula-fed and supplemented with Vitamin B complex as placebo. The groups were divided by double-blind and randomized method. There were no differences in the 3 groups in sex ratio, growth status and serum zinc concentration at the beginning of the study. Anthropometric data were obtained at 0, 3 and 6 months.

[Serum and tissue copper, zinc and selenium levels in patients with gastric carcinoma].

Serum and tissue copper, zinc and selenium levels were measured in patients with gastric carcinoma. The mean level of serum copper in patients with gastric carcinoma (42 cases) was 950 +/- 130 ug/L, which was higher than 800 +/- 70 ug/L of the control (30 cases, P less than 0.05). The serum selenium level in patients with gastric carcinoma was lower than that in the control (63 +/- 15 ug/L vs 85 +/- 8 ug/L, P less than 0.05). No significant difference in serum zinc level was found between the patient and control groups. In cancer tissues, the mean concentration of copper was 13.5 +/- 2.6 micrograms/g dry weight, which was much higher than 7.1 +/- 1.6 micrograms/g dry weight in the intact gastric mucosa (P less than 0.01). The activity of superoxide dismutase (SOD) in cancer tissue was 95 +/- 10 u/mg-protein, which was lower than 124 +/- 12 u/mg-protein in the intact gastric mucosa (P less than 0.05). The above changes may facilitate production of free radicals, tissue damage and carcinogenesis.