Gene therapy to restore prostacyclin presence to injured endothelium

These preliminary studies demonstrate the feasibility of restoration of prostacyclin synthesis in mechanically-injured porcine carotid arteries following angioplasty. Our initial data suggest the possibility of inhibiting thrombus development by adenovirus-CMV-PGHS-1 therapy in the initial 10 days following angioplasty.

Developmental plasticity of reticulospinal and vestibulospinal axons in the north American opossum, Didelphis virginiana

We have shown previously that rubral axons grow around a lesion of their spinal pathway in the North American opossum if it is made at early stages of development. In the present experiments, we have asked whether reticular and vestibular axons have the same ability. The spinal cord was hemisected at postnatal day 20, 12, or 5, well within the critical period for rubrospinal plasticity, and, approximately 30 days later, bilateral injections of fast blue were made about four segments caudal to the lesion. The pups were killed 4 or 5 days after the injections. In most of the animals lesioned on postnatal day 20, labeled neurons were not found in the medial part of the pontine reticular nucleus or the dorsal part of the lateral vestibular nucleus ipsilateral to the lesion. The spinal projections from both areas are exclusively ipsilateral. When the lesions were made at postnatal day 12 or 5, however, labeled neurons were present in both areas, suggesting that they supported axons that had grown caudal to the lesion. As was expected from previous studies, rubral neurons were labeled contralateral to the lesion in all three groups. In the opossum, as in other species, the red nucleus projects contralaterally. We conclude that reticular and vestibular axons, like axons from the red nucleus, grow around a lesion of their pathway during development and that the critical period for their plasticity ends earlier than that for rubrospinal axons.

Characterization of the genomic structure, chromosomal location and promoter of human prostaglandin H synthase-2 gene

Prostaglandin H synthase (PGHS) is the rate-limiting enzyme in the conversion of arachidonic acid to prostanoids. The human PGHS has two isoforms. PGHS-1 is a house keeping gene whereas PGHS-2 is an inducible gene. We reported here the isolation of the entire PGHS-2 gene and its 5'-flanking region from a human bacteriophage P1 genomic library. The gene containing 10 exons is 7.5 kb in length and located at chromosome 1. The transcriptional start site was mapped at 134 bases upstream from the ATG start codon. Nucleotide sequence of 1.8 kb promoter region contains a TATA box and a number of potential regulatory elements including CRE, NF-kappa B, Sp1 and AP2 sites. Studies of the promoter activity showed that the first 460 nucleotides of 5'-flanking region efficiently drove transcription of the luciferase reporter gene in human umbilical vein endothelial cells upon stimulation with phorbor ester.

[Molecular screening and prenatal diagnosis of the deletional alpha-thalassemia by polymerase chain reaction amplification]

For the genetic counselling, 8,432 blood samples from Chinese couples were screened for detecting alpha-thalassemia in Guangzhou city. The positive diagnosis of 646 (7.66%) alpha-thalassemia patients was made. One hundred DNA random samples from the above positive cases were collected and were analysed by using polymerase chain reaction (PCR) to determine the genotype of alpha-thalassemia of Southeast Asian deletion(--SEA/). Of 100 alpha-thalassemia individuals screened for the (--SEA/) mutation, 99 (96 with alpha-thalassemia trait and 3 with hemoglobin H disease) were detected by the present method. This mutation was not found in the remaining one with alpha-thalassemia compound Hb Q. We also used this assay to analyse DNA samples from cord blood in 6 pregnancies at risk of Bart's hydrops fetalis, in 1 at risk of Hb H disease for prenatal diagnosis.

[Transurethral laser prostatectomy: report of 200 cases]

From August 1988 to May 1993, 200 patients with benign prostatic hyperplasia (BPH) were treated by transurethral laser prostatectomy (TULP) in our hospital. 165 patients were followed up for 6 months to 4.5 years and the results showed excellent effect in 128 cases, improved 32 cases, the total effectiveness was 97%. TULP, a safe and effective therapy for BPH, have more wide operative indication range but it is not suitable for patients with carcinoma of prostate.

[Transurethral non-contact laser treatment of prostatic hypertrophy]

66 cases of prostatic hypertrophy have been treated by transurethral non-contact Nd:YAG laser irradiation since April 1993. Sixty patients regained unobstructed urination within 1 week and 6 within 2 weeks after operation. The symptoms of the treated group were improved with the necrotic tissues gradually peeling off in 3 to 6 weeks. The short-term follow-up indicated that the prostatic gland distinctly reduced and residual urine decreased or vanished after treatment. Three patients had one of the following complications: urinary tract infection, epididymitis or urinous infiltration. These complications were treated appropriately. This therapy is ideal for the treatment of prostatic hypertrophy.

Gene therapy for vascular diseases

Gene transfer by virus- and liposome-mediated vectors has potential for treating genetic diseases, cancer, and cardiovascular diseases. In this article, we discuss the general principle and techniques for gene transfer and the specific issues facing therapy for vascular diseases. We also propose a strategy for using virus-mediated gene transfer to restore the vasoprotective function of the vascular wall, thereby preventing vascular thrombosis. Experimental data from ongoing work in our laboratories are presented to illustrate the importance of this approach in vascular gene transfer therapy.

The developing organ of Corti contains retinoic acid and forms supernumerary hair cells in response to exogenous retinoic acid in culture

The mammalian organ of Corti has one of the most highly ordered patterns of cells in any vertebrate sensory epithelium. A single row of inner hair cells and three or four rows of outer hair cells extend along its length. The factors that regulate the formation of this strict pattern are unknown. In order to determine whether retinoic acid plays a role during the development of the organ of Corti, exogenous retinoic acid was added to embryonic mouse cochleae in vitro. Exogenous retinoic acid significantly increased the number of cells that developed as hair cells and resulted in large regions of supernumerary hair cells and supporting cells containing two rows of inner hair cells and up to 11 rows of outer hair cells. The effects of retinoic acid were dependent on concentration and on the timing of its addition. Western blot analysis indicated that cellular retinoic acid binding protein (CRABP) was present in the sensory epithelium of the embryonic cochlea. The amount of CRABP apparently increased between embryonic day 14 and postnatal day 1, but CRABP was not detectable in sensory epithelia from adults. A retinoic acid reporter cell line was used to demonstrate that retinoic acid was also present in the developing organ of Corti between embryonic day 14 and postnatal day 1, and was also present in adult cochleae at least in the vicinity of the modiolus. These results suggest that retinoic acid is involved in the normal development of the organ of Corti and that the effect of retinoic acid may be to induce a population of prosensory cells to become competent to differentiate as hair cells and supporting cells.

Direct genotyping and prenatal diagnosis of beta-thalassemia in Chinese by polymerase chain reaction mediated restriction fragment length polymorphism method

The molecular basis of beta-thalassemia is predominantly point mutations in the beta-globin gene. Frameshift 41-42 (-CTTT), IVS-2 position 654 (C-->T) mutation, nonsense codon 17 (A-->T), TATA box position -28 (A-->G) mutation and frameshift 71-72 (+A) account for more than 95% of beta-thalassemia alleles in the population of South China. We have developed a polymerase chain reaction (PCR)-mediated restriction fragment length polymorphism (RFLP) method for the identification of these alleles. In this method, artificial mispairing bases in PCR-amplified products were created to distinguish normal from mutant alleles on the basis of RFLPs. The size of the five PCR-amplified DNA fragments that may potentially contain the above five types of mutations is 93 or 89 bp (codons 41-42), 221 bp (IVS-2 nt 654), 110 bp (codon 17), 123 bp (TATA box nt -28), and 97 or 98 bp (codons 71-72). After these fragments were digested with Hinc II, Mae III, Nhe I, EcoR I, and Dde I, respectively, the allele-specific RFLPs produced were analyzed by gel electrophoresis. DNA samples of 24 patients with the above five types of beta-thalassemia were investigated with the present method and allele-specific oligonucleotide (ASO) probing simultaneously. We used this method in the prenatal diagnosis of 14 Chinese families for beta-thalassemia. The results obtained by the present method correspond well with those by the ASO probe test.

Quantitative analysis of vascular prostaglandin H synthase mRNA levels by competitive polymerase chain reaction

Prostaglandin H synthase (PGHS) occupies a central position in the biosynthesis of prostaglandins, thromboxane, and prostacyclin. Expression of this enzyme is enhanced by inflammatory cytokines and phorbol esters. Because of the low abundance of PGHS, PGHS mRNA levels in tissues and cells were difficult to measure accurately. In this study, we quantified vascular PGHS-1 mRNA levels by a competitive polymerase chain reaction assay. The mean basal PGHS-1 level in cultured human umbilical vein endothelial cells (HUVECs) was 24.3 +/- 10.6 amol/microgram RNA. Treatment of the HUVECs with recombinant human interleukin-1 beta at 37 degrees C for 4 hours increased the mRNA to 49.1 +/- 9.1 amol/microgram RNA, a 2.1-fold increase. Treatment of the cells with phorbol 12-myristate 13-acetate at 37 degrees C for 4 hours caused a 1.7-fold increase in the mRNA level. This procedure was utilized to measure PGHS-1 mRNA levels in rabbit abdominal aorta, inferior vena cava, liver, kidney, and lung. The aortic mRNA level (9.2 +/- 1.9 amol/microgram RNA) was about 5 times higher than the inferior vena caval level (2.4 +/- 1.3 amol/microgram RNA) but only slightly higher than the level of other organs. These results reveal a significant difference in PGHS-1 mRNA levels between arterial and venous tissues. The synthase mRNA levels in organs such as liver, kidneys, and lungs do not differ significantly. The PCR assay should be valuable for studying the role of PGHS expression in disease states.

Enhanced prostacyclin synthesis in endothelial cells by retrovirus-mediated transfer of prostaglandin H synthase cDNA

A retroviral vector (BAG) was used to transfer human prostaglandin H synthase (PGHS-1) gene into a human endothelial cell line for enhancement of PGI2 synthesis. Cells infected with BAG containing PGHS-1 cDNA in the sense orientation relative to the retroviral promoter (PGHS(S)) expressed a 30-fold increase in mRNA but, due to a reading frame shift, did not show an increase in PGHS protein or in PGI2 synthesis, while those with PGHS-1 in reverse orientation relative to the viral promoter (PGHS(R)), produced a > 10-fold increase in PGHS mRNA over the control (169 +/- 22 vs 14.8 +/- 1.2 amol/micrograms RNA) with a concordant increase in PGHS protein (5.82 +/- 1.07 vs 0.23 +/- 0.04 ng/mg protein) and enzyme activity. Primer extension analysis of PGHS(R) revealed two transcription start sites located in the SV40 late promoter region adjacent to PGHS-1 cDNA. PGHS(R) cells produced a high basal PGI2 level which was increased by several-fold in response to stimulation by ionophore, arachidonic acid, and thrombin. Kinetic analysis revealed the PGI2 synthetic rate to be 14 ng/min-1 per million cells and t1/2 of PGI2 synthesis, 13.3 min. These findings indicate that transfer of PGHS-1 gene into vascular cells enhances PGI2 synthesis and may be a useful strategy for restoring thromboprotective property of damaged blood vessels.

Characterization of the promoter of human prostaglandin H synthase-1 gene

The gene of human prostaglandin H synthase-1 (PGHS-1,EC 1.14.99.1) was isolated from a human cosmid library and was contained in two overlapping clones. Multiple transcriptional start sites were identified. The major one located 136 bases upstream from the ATG initiation codon. The promoter region contains no canonical TATA box but possesses a high G+C content. These observations suggest that PGHS-1 gene has the characteristics of a housekeeping gene. Both 0.8 and 0.4 kb of the 5'-flanking sequence of the PGHS-1 gene can confer transcriptional activity.

The origins of descending projections to the lumbar spinal cord at different stages of development in the North American opossum

We have employed the retrograde transport of fast blue (FB) to identify the origins of descending projections to the lumbar cord of the opossum from postnatal day (PD)1, 12-13 days after conception, to maturity. When FB injections were made into the lumbar cord at PD1, supraspinal labeling was sparse and limited to the hypothalamus, the reticular formation, the coeruleus complex, the caudal raphe, and, in one case, the interstitial nucleus of the medial longitudinal fasciculus and the lateral vestibular nucleus. Only a few propriospinal neurons were labeled at cervical and thoracic levels. By PD3, however, supraspinal and propriospinal labeling was abundant and present in most of the areas labeled in the adult animal. A notable exception was the red nucleus which was not labeled until approximately PD10. Our results have been compared with those described in other species and discussed in light of their relevance to the development of descending control over hindlimb movement and developmental plasticity of descending spinal pathways.

The origins of supraspinal projections to the cervical and lumbar spinal cord at different stages of development in the gray short-tailed Brazilian opossum, Monodelphis domestica

We have used the retrograde transport of Fast blue (FB) to study the origins of supraspinal projections to the lumbar and cervical spinal cord at different stages of development in the Brazilian, short-tailed opossum, Monodelphis domestica. Monodelphis was chosen for study because its young are born in a very immature state, 14-15 days after copulation, making it possible to manipulate its nervous system in an embryonic state without intra-uterine surgery. When injections of FB were made into the lumbar cord at postnatal day (PD) 1, neurons were labeled within several areas of the reticular formation (the retroambiguus nucleus, the ventral and dorsal reticular nuclei of the medulla, the gigantocellular reticular nucleus, the lateral paragigantocellular reticular nucleus, and the pontine reticular nucleus), the presumptive coeruleus complex, and the lateral vestibular nucleus. In many cases, labeled neurons were also found within the caudal raphe and the presumptive interstitial nucleus of the medial longitudinal fasciculus. The results of immunocytochemical studies provided evidence for catecholaminergic and serotoninergic neurons in the brainstem at PD1 and for axons of both phenotypes in the spinal cord. By PD3, labeled neurons were found within the ventral gigantocellular and ventral pontine nuclei of the reticular formation, the spinal trigeminal nucleus, and the presumptive paraventricular nucleus of the hypothalamus. When injections were made at PD4, neurons were also labeled within the medial and inferior vestibular nuclei, the red nucleus, the mesencephalic nucleus of the trigeminal nerve, the presumptive nucleus of Edinger-Westphal and the lateral hypothalamus. By at least PD7, the pattern of supraspinal labeling was similar to that obtained at older ages and in the adult animal. When FB was injected into the cervical cord at PD1, neurons were labeled in all of the areas labeled by lumbar injections at the same age and in larger numbers. In addition, labeled neurons were found within the ventral gigantocellular and spinal trigeminal nuclei. When cervical injections were made at PD15, labeled neurons were found within the deep cerebellar nuclei and amygdala and by PD17 they were also present within the superior colliculus and cerebral cortex. In some cases, cortical labeling was present outside the areas labeled by comparable injections in adult animals.(ABSTRACT TRUNCATED AT 400 WORDS)

Transforming growth factor-beta 1 and IL-4 regulate the adhesiveness of Peyer's patch high endothelial venule cells for lymphocytes

The adhesion of lymphocytes to endothelial cells lining the postcapillary high endothelial venules (HEV) is the first step in their emigration from the bloodstream into lymph nodes and Peyer's patches (PP). We have recently shown that the adhesiveness of cultured rat lymph node and PP HEV cells for thoracic duct lymphocytes can be increased significantly by pretreatment with TNF-alpha, IFN-gamma, and IL-4. In the present study we investigated the role of transforming growth factor-beta 1 (TGF-beta) on the adhesiveness of nonstimulated and cytokine-stimulated PP HEV cells for rat lymphocytes. The results indicated that at picomolar concentrations, TGF-beta significantly (p less than 0.001) decreased the ability of PP HEV cells to adhere 51Cr-labeled rat lymphocytes. Maximal inhibition was observed with a TGF-beta dose of 0.5 ng/ml and an incubation time of 6 to 12 h. TGF-beta did not affect the morphology of HEV cells and had no adverse effect on their viability. Moreover, the decrease in HEV adhesiveness by TGF-beta was reversible, with lymphocyte binding returning to control level 24 h after removal of the cytokine. The specificity of TGF-beta was confirmed by the ability of neutralizing anti-TGF-beta 1 antibody, but not control serum, to abolish the inhibitory properties of the cytokine. In addition, TGF-beta completely abrogated the increased adhesiveness of PP HEV cells normally induced by TNF-alpha or IFN-gamma. In contrast, TGF-beta had no effect on the stimulating effects of IL-4. Moreover, preincubation of PP HEV cells with TGF-beta did not alter the ability of these cells to respond to IL-4. Importantly, the adhesion of rat lymphocytes to IL-4-stimulated PP HEV cells can be blocked by pretreatment of lymphocytes with the PP-homing receptor-specific 1B.2.6 antibody whereas pretreatment of human mononuclear cells with anti-very late activation antigen-4 alpha antibody inhibited only partially the binding of these cells to the IL-4-stimulated PP HEV monolayers. Taken together, these findings strongly suggest that TGF-beta and IL-4 play important regulatory roles in lymphocyte-HEV adhesion and that the stimulatory effect of IL-4 is mediated at least in part through the increased expression of organ-specific ligands on HEV cells.

Transforming growth factor-beta 1 and IL-4 regulate the adhesiveness of Peyer's patch high endothelial venule cells for lymphocytes

The adhesion of lymphocytes to endothelial cells lining the postcapillary high endothelial venules (HEV) is the first step in their emigration from the bloodstream into lymph nodes and Peyer's patches (PP). We have recently shown that the adhesiveness of cultured rat lymph node and PP HEV cells for thoracic duct lymphocytes can be increased significantly by pretreatment with TNF-alpha, IFN-gamma, and IL-4. In the present study we investigated the role of transforming growth factor-beta 1 (TGF-beta) on the adhesiveness of nonstimulated and cytokine-stimulated PP HEV cells for rat lymphocytes. The results indicated that at picomolar concentrations, TGF-beta significantly (p less than 0.001) decreased the ability of PP HEV cells to adhere 51Cr-labeled rat lymphocytes. Maximal inhibition was observed with a TGF-beta dose of 0.5 ng/ml and an incubation time of 6 to 12 h. TGF-beta did not affect the morphology of HEV cells and had no adverse effect on their viability. Moreover, the decrease in HEV adhesiveness by TGF-beta was reversible, with lymphocyte binding returning to control level 24 h after removal of the cytokine. The specificity of TGF-beta was confirmed by the ability of neutralizing anti-TGF-beta 1 antibody, but not control serum, to abolish the inhibitory properties of the cytokine. In addition, TGF-beta completely abrogated the increased adhesiveness of PP HEV cells normally induced by TNF-alpha or IFN-gamma. In contrast, TGF-beta had no effect on the stimulating effects of IL-4. Moreover, preincubation of PP HEV cells with TGF-beta did not alter the ability of these cells to respond to IL-4. Importantly, the adhesion of rat lymphocytes to IL-4-stimulated PP HEV cells can be blocked by pretreatment of lymphocytes with the PP-homing receptor-specific 1B.2.6 antibody whereas pretreatment of human mononuclear cells with anti-very late activation antigen-4 alpha antibody inhibited only partially the binding of these cells to the IL-4-stimulated PP HEV monolayers. Taken together, these findings strongly suggest that TGF-beta and IL-4 play important regulatory roles in lymphocyte-HEV adhesion and that the stimulatory effect of IL-4 is mediated at least in part through the increased expression of organ-specific ligands on HEV cells.

The response of rubrospinal neurons to axotomy at different stages of development in the North American opossum

Rubral axons can grow around a lesion of their pathway in the thoracic spinal cord of developing opossums and a critical period exists for that plasticity. The critical period probably begins when rubral axons first grow into the thoracic cord, and it extends until approximately postnatal day 30. We previously noted that most rubrospinal neurons die after transection of their axon during the critical period, suggesting that plasticity results primarily from growth of axons not damaged by the lesion (Xu and Martin, J. Comp. Neurol. 279, 368-381, 1989). That observation led us to study the response of rubrospinal neurons to axotomy in more detail and at additional stages of development, using a prelabeling paradigm. We first injected fast blue (FB) into the caudal thoracic or rostral lumbar spinal cord in animals ranging from estimated postnatal day 9 to 50 and, about 4 days later, lesioned the rubrospinal tract several segments rostral to the injection. Approximately 30 days later, the animals were killed so that the red nucleus could be searched for labeled neurons. During the critical period for plasticity, rubrospinal neurons showed signs of degeneration 1 week after their axon was cut. When animals were killed 2-3 weeks after lesioning, there was an obvious decrease in axotomized neurons within the red nucleus, and by 4 weeks, more than 75% of them had degenerated. The marked susceptibility of rubrospinal neurons to axotomy during the critical period for plasticity is consistent with the hypothesis that developmental plasticity of the rubrospinal tract results primarily from growth of axons that were not damaged by the lesion. Our results also suggest that survival of axotomized rubrospinal neurons increases with age.

Differentiation-associated expression of prostaglandin H and thromboxane A synthases in monocytoid leukemia cell lines

To elucidate the differentiation-associated expression of enzymes catalyzing arachidonic acid metabolism, we measured arachidonate metabolites by reverse-phase high pressure liquid chromatography in monocytoid leukemia (ML-1, THP-1, and U937) and myeloid leukemia (KG-1) cell lines. Undifferentiated ML-1 or THP-1 cells produced trace amounts of eicosanoids via the cyclooxygenase (COX) and lipoxygenase (LOX) pathways. Upon differentiation induced by phorbol ester (phorbol 12-myristate 13-acetate [PMA]), metabolites via the COX pathway were increased by 100-fold in ML-1 and THP-1 cells, while the LOX products remained barely detectable. All the COX metabolites were elevated, but thromboxane A2 (TXA2) formation was threefold higher in ML-1 cells than in THP-1 cells. Similar time-related increases in COX metabolites were observed in THP-1 cells induced to differentiate with retinoic acid. Undifferentiated U937 cells were capable of generating a much higher quantity of COX products than ML-1 or THP-1 cells, but, upon PMA-induced differentiation, COX products were increased by only two-fold to threefold over the undifferentiated cells and the total COX products in differentiated U937 cells were only one-seventh of those produced by differentiated ML-1 or THP-1 cells. KG-1 cells had an entirely different metabolic profile. They produced a large quantity of a metabolite coeluted with prostaglandin D2, and PMA had no effect on inducing changes in arachidonic acid (AA) metabolism. Increased COX metabolite formation in differentiated THP-1 and ML-1 cells was due to an enhanced level of prostaglandin H synthase enzyme mass, as measured by Western blot analysis. The TXA synthase activity was also increased by approximately 100-fold in PMA-induced ML-1 cells and 10-fold in THP-1 cells. These findings indicate that increased expression of prostaglandin H and TXA synthase enzymes is a feature of differentiated monocytoid leukemia cell lines.

Ipsilaterally projecting rubrospinal neurons in adult and developing opossums

We have combined injections of Fast Blue with lesions of the rubrospinal tract rostral and contralateral to them to determine if an ipsilateral rubrospinal projection exists in adult or developing opossums and, if so, to characterize the neurons giving rise to it. Although the results indicate that some rubral neurons project ipsilaterally, they are very few in number. Using quantitative and image analysis techniques, we have shown that 0.6% of the rubral neurons that project to the lumbar cord in adult opossums do so ipsilaterally and that such neurons are comparable in location and size to those that project contralaterally. Similar results were obtained in developing opossums. Our results are discussed in light of rubrospinal development and ongoing experiments related to rubrospinal plasticity.

Tissue-specific homing receptor mediates lymphocyte adhesion to cytokine-stimulated lymph node high endothelial venule cells

Lymphocytes bind to high endothelial venule (HEV) cells as the first step in the migration of these cells into lymph nodes (LN) and Peyer's patches (PP). In this study we isolated and cultured HEV cells from rat LN and investigated the effects of cytokines on the adhesiveness of these cells for lymphocytes. The results showed that lymphocytes from thoracic duct, spleen and LN adhered preferentially to the cultured LN HEV cells compared to cells isolated from the thymus and bone marrow. The adhesiveness of LN HEV cells for thoracic duct lymphocytes (TDL) was significantly increased in a dose- and time-dependent manner by pretreatment of the HEV cells with tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) or interleukin-4 (IL-4). In contrast, pretreatment of HEV cells with IL-1, IL-6 or IL-7 did not alter the capacity of LN HEV cells to adhere lymphocytes. Furthermore, incubation of LN HEV cells with suboptimal doses of TNF and IL-4, IFN-gamma and IL-4, or TNF-alpha and IFN-gamma increased significantly the endothelial adhesiveness. Interestingly, although IL-1 alone did not promote the adhesiveness of HEV cells, the cytokine synergized with suboptimal doses of IL-4 and TNF-alpha to increase the adhesiveness. The adhesion of TDL to non-stimulated and IL-4-stimulated LN HEV cells could be blocked specifically by treatment of lymphocytes with the LN homing-receptor-specific A.11.5 monoclonal antibody (mAb). In contrast, lymphocytes pretreated with the PP-homing receptor-specific 1B.2.6 mAb or the antileucocyte common antigen (OX1) mAb adhered normally to the HEV cells. Taken together, these results indicate that the baseline and cytokine-stimulated bindings between lymphocytes and LN HEV cells are mediated by adhesive mechanisms that regulate lymphocyte migration into LN in vivo and provide strong evidence that cytokines are central mediators of organ-specific lymphocyte migration.

Evidence for new growth and regeneration of cut axons in developmental plasticity of the rubrospinal tract in the North American opossum

We have shown previously that rubral axons can grow around a lesion of their spinal pathway in the developing opossum and that a critical period exists for that plasticity (Martin and Xu, Dev Brain Res 39:303, 1988). Since most rubrospinal neurons degenerate after axotomy during the critical period, we have proposed that plasticity results primarily from growth of late arriving axons around the lesion rather than regeneration of cut axons (Xu and Martin, J Comp Neurol 279:368, 1989). In the present study, we used a double-labeling paradigm to test that hypothesis. Four groups of pouch young opossums received bilateral or unilateral injections of Fast Blue (FB) into the caudal thoracic or rostral lumbar cord (T12-L2) at different ages in order to label rubrospinal neurons. Three or 4 days later, the rubrospinal tract was transected unilaterally, four to five segments rostral to the injection(s). If the injection was unilateral, the lesion was made ipsilateral to it. The animals were maintained for about 1 month before a second marker, Diamidino Yellow (DY), was injected, usually bilaterally, between the FB injection(s) and the lesion. The animals were maintained for about 5 days before sacrifice and sections through the red nucleus and spinal cord were examined with a fluorescence microscope. During the critical period for plasticity, only a few rubral neurons contralateral to the lesion were labeled by FB alone, supporting our previous contention that most axotomized neurons degenerate. In contrast, many neurons were labeled by DY alone, indicating that their axons were not present in the caudal cord at the time of the FB injection and that they grew around the lesion during the 1 month survival to incorporate DY. A few double-labeled neurons were also found. One interpretation of such neurons is that they survived axotomy, as evidenced by the presence of FB, and supported axons which grew around the lesion to take up DY. Another interpretation is that they supported late growing axons which incorporated residual FB as well as DY. In order to choose between these alternatives, a similar double-labeling paradigm was carried out, but with removal of FB at the time of the lesion. Since a few neurons were still double labeled, we conclude that regeneration of cut axons also contributed to rubrospinal plasticity. Our results support our previous suggestion that developmental plasticity of the rubrospinal tract results primarily from growth of late arriving axons around the lesion, but they also suggest that regeneration of cut axons occurs.

Characterization of the 25-kilodalton subunit of the energy-transducing NADH-ubiquinone oxidoreductase of Paracoccus denitrificans: sequence similarity to the 24-kilodalton subunit of the flavoprotein fraction of mammalian complex I

The NADH dehydrogenase complex isolated from Paracoccus denitrificans is composed of approximately 10 unlike polypeptides [Yagi, T. (1986) Arch. Biochem. Biophys. 250, 302-311]. Structural genes encoding the subunits of this enzyme complex constitute at least one gene cluster [Xu, X., Matsuno-Yagi, A., & Yagi, T. (1991) Biochemistry 30, 6422-6428]. The 25-kDa subunit (NQO2), which has been isolated from sodium dodecyl sulfate-polyacrylamide gels, is a polypeptide of this enzyme complex. The partial N-terminal amino acid sequence and amino acid composition of the NQO2 subunit have been determined. On the basis of the amino acid sequence, the NQO2 gene was found to be located 1.7 kilobase pairs upstream of the gene for NADH-binding subunit (NQO1). The complete nucleotide sequence of the NQO2 gene was determined. It is composed of 717 base pairs and codes for 239 amino acid residues with a calculated molecular weight of 26,122. The NQO2 subunit is homologous to the Mr 24,000 subunit of the mammalian mitochondrial NADH-ubiquinone oxidoreductase which bears an electron paramagnetic resonance-visible binuclear iron-sulfur cluster (probably cluster N1b). Comparison of the predicted amino acid sequence of the Paracoccus NQO2 subunit with those of its mammalian counterparts suggests putative binding sites for the iron-sulfur cluster. In addition, nucleotide sequencing shows the presence of two unidentified reading frames between the NQO1 and NQO2 genes. These are designated URF1 and URF2 and are composed of 261 and 642 base pairs, respectively. The possible function of the protein coded for the URF2 is discussed.

The NADH-binding subunit of the energy-transducing NADH-ubiquinone oxidoreductase of Paracoccus denitrificans: gene cloning and deduced primary structure

The NADH dehydrogenase complex isolated from Paracoccus denitrificans is composed of approximately 10 unlike polypeptides and contains noncovalently bound FMN, non-heme iron, and acid-labile sulfide [Yagi, T. (1986) Arch. Biochem. Biophys. 250, 302-311]. The NADH-binding subunit (Mr = 50,000) of this enzyme complex was identified by direct photoaffinity labeling with [32P]NADH [Yagi, T., & Dinh, T.M. (1990) Biochemistry 29, 5515-5520]. Primers were synthesized on the basis of the N-terminal amino acid sequence of this polypeptide, and these primers were used to synthesize an oligonucleotide probe by the polymerase chain reaction. This probe was utilized to isolate the gene encoding the NADH-binding subunit from a genomic library of P. denitrificans. The nucleotide sequence of the gene and the deduced amino acid sequence of the entire NADH-binding subunit were determined. The NADH-binding subunit has 431 amino acid residues and a calculated molecular weight of 47,191. The encoded protein contains a putative NAD(H)-binding and an iron-sulfur cluster-binding consensus sequence. The deduced amino acid sequence of the Paracoccus NADH-binding subunit shows remarkable similarity to the alpha subunit of the NAD-linked hydrogenase of Alcaligenes eutrophus H16. When partial DNA sequencing of the regions surrounding the gene encoding the NADH-binding subunit was carried out, sequences homologous to the 24-, 49-, and 75-kDa polypeptides of bovine complex I were detected, suggesting that the structural genes of the Paracoccus NADH dehydrogenase complex constitute a gene cluster.

Nucleotide sequence of the gene encoding NADH dehydrogenase from an alkalophile, Bacillus sp. strain YN-1

The gene encoding NADH dehydrogenase from an alkalophile, Bacillus sp., was cloned and sequenced. The cloned DNA fragment contained an open reading frame of 1,557 nucleotides which encodes a polypeptide composed of 519 amino acid residues (Mr 55,830). The predicted amino acid sequence was consistent with the partial amino acid sequences including the N-terminal and C-terminal sequences determined in a previous study. Sequence comparison with other flavoenzymes revealed high homology between the present dehydrogenase and Escherichia coli thioredoxin reductase.

The origin of serotoninergic projections to the lumbosacral spinal cord at different stages of development in the North American opossum

We have employed immunohistochemistry and the retrograde transport of Fast blue to study the origin of serotoninergic projections to the lumbosacral spinal cord at different stages of development in the North American opossum. A few serotoninergic axons are present in the lumbosacral cord at birth, 12 days after conception, and serotoninergic neurons are numerous in the brainstem where they are present in most, if not all, of the areas which contain them in the adult animals. A few neurons of the caudal raphe and adjacent reticular formation were labeled by lumbar injections of Fast blue on postnatal day 1, and by postnatal day 3, labeled neurons were numerous within all areas which provide serotoninergic projections to the lumbosacral cord in adult animals. By postnatal day 11, it was possible to combine Fast blue labeling with immunofluorescence to show that some of the labeled neurons were serotoninergic. By postnatal day 24, neurons which provide serotoninergic projections to the lumbosacral cord were especially numerous and some of them were found in areas which do not provide comparable projections in adult animals. In developing and adult animals, few, if any, neurons were labeled in the dorsal raphe or superior central nuclei. We have shown previously that serotoninergic axons do not innervate laminae I and II of the lumbosacral cord until approximately postnatal day 50, although they are present in the marginal zone at birth and have grown into laminae III-X by postnatal day 15. Since serotoninergic axons which project to laminae I and II originate within the raphe magnus and adjacent reticular formation, and those areas provide serotoninergic projections to the spinal cord well before postnatal day 50, it is possible that serotoninergic innervation of laminae I and II is provided by late growth of collaterals from axons that have been present in the marginal zone for some time.

Identification of the NADH-binding subunit of energy-transducing NADH-quinone oxidoreductase (NDH-1) of thermus thermophilus HB-8

The energy-transducing NADH--quinone oxidoreductase (NDH-1) isolated from Thermus thermophilus HB-8 is composed of approximately 10 unlike polypeptides and contains noncovalently bound FMN and at least three iron-sulfur clusters [Yagi, T., Hon-nami, K., and Ohnishi, T. (1988) Biochemistry 27, 2008-2013]. When NDH-1 of T. thermophilus HB-8 was irradiated by short UV light in the presence of [adenylate-32P]NADH or [adenylate-32P]NAD, radioactivity was incorporated into a single polypeptide of Mr 47,000. The labeling of the Mr 47,000 polypeptide was diminished when UV irradiation of the enzyme complex with [adenylate-32P]NAD was carried out in the presence of NADH or deamino-NADH which act as substrates for the NDH-1, but not in the presence of NADP(H) or AMP which act neither as substrates nor as competitive inhibitors. These results strongly suggest that the Mr 47,000 polypeptide is an NADH-binding subunit of the NDH-1 of T. thermophilus HB-8.

Debrisoquine hydroxylation and sulfamethazine acetylation in a Chinese population

Both debrisoquine hydroxylation and sulfamethazine acetylation phenotypes were studied in the same native Chinese population. Debrisoquine hydroxylation status was determined by HPLC assay of debrisoquine metabolic ratio in urine after a single oral dose of 10 mg debrisoquine. Three poor metabolizers were found in 220 subjects (1.36%). One hundred and one subjects of this population previously debrisoquine phenotyped were also tested for acetylation phenotyping on a separate occasion. Their acetylation status were determined by HPLC assay of "% acetylation" after a single oral dose of 1 g sulfamethazine. Twenty (19.8%) slow acetylators were found. There were no significant association between the 2 metabolic pathways.

[Antifertility actions of gossypol derivatives and analogues]

This paper reports the results of 32 gossypol derivatives and analogues. Among 12 compounds screened by oral administration to male rats, only dipotassium gossypolate (NC030) exhibited an antifertility activity similar to gossypol. Among 24 compounds screened by injecting into pouches of cauda epididymides of rats, 10 exhibited spermicidal activities.

The response of rubrospinal neurons to axotomy in the adult opossum, Didelphis virginiana

To provide endpoints for developmental studies of rubrospinal plasticity in the North American opossum, we have attempted to determine the degree to which rubrospinal neurons survive axotomy in the adult animal. Bilateral or unilateral injections of the long-lasting fluorescent marker fast blue were made into the T-10 or the T-11 segment of the spinal cord to label rubrospinal neurons, and 7 days later, the rubrospinal tract was cut unilaterally four segments rostral to the injection(s). In cases with unilateral injections, the lesion was made ipsilateral to the injection. The animals were allowed to survive for 30-60 days before being sacrificed and perfused so that sections through the red nuclei could be examined for labeled neurons. The results show that most axotomized neurons survived the lesion, suggesting that lesion-dependent cell death is not a major factor in the failure of the rubrospinal tract to regenerate in the adult animal.

[Pathological analysis of 100 cases of severe deep stromal herpetic keratitis]

Based on the pathological observation of 100 cases of severe deep stromal herpetic keratitis, the author suggested the classification of the disease, according to the nature and progression of the chronic inflammation, into 2 categories of the acute active stage (40%) and chronic progressive stage (60%), which were in agreement with the clinical manifestations and also satisfactorily explained the pathogenetic basis of the clinical types. Inflammatory granuloma appeared in 21% of the cases, indicating that the corneal lesions were still in progress.

[Ultraviolet spectrophotometric determination of cantharidin in Mylabris]

In this study the content of cantharidin in Mylabris was analyzed quantitatively by UV. Analytical results thus obtained agree well with those by the neutralization method set forth in ChP. The average recovery of cantharidin is 99.98% and the coefficient of variation is 0.719%.

Tryptic digestion of NADH dehydrogenase from alkalophilic Bacillus

The alkalophile NADH dehydrogenase (NADH: 2,6-dichlorophenolindophenol oxidoreductase) [EC 1.6.99.3] consists of two identical subunits of 65 kDa, and each subunit contains the catalytic and liposome-binding regions. On treatment with trypsin, the polypeptide exhibiting the liposome-binding property in one of the subunits was digested to form an enzymatically active hetero-dimer (40 and 65 kDa), and then the polypeptide in the other subunit was digested to form an active homo-dimer (40 and 40 kDa). The hetero-dimer bound to liposomes, but the homo-dimer did not. Kinetic analysis showed that removal of one or two of the polypeptides in the enzyme slightly affects its kinetic parameters. For all the enzyme species, NAD inhibited competitively with respect to NADH and non-competitively with respect to 2,6-dichlorophenolindophenol. The partially determined amino acid sequence of this alkalophile enzyme suggested that (i) a long random-coiled peptide (58 amino acid residues) or a portion of the peptide is located between the polypeptides with liposome-binding and catalytic properties, (ii) the polypeptide exhibiting liposome-binding property is in the amino terminal region of the enzyme, (iii) the amino acid sequences around the subtilisin and trypsin cleavage sites of the peptide are hydrophilic and on the surface of the protein molecule and therefore are susceptible to digestion, and (iv) the FAD-binding site is located near the amino terminal region of the catalytic region.

Developmental plasticity of the rubrospinal tract in the North American opossum

We have shown previously that rubral axons can grow caudal to a lesion of their pathway at thoracic levels of the spinal cord in the developing opossum, Didelphis virginiana. In the present report we expand on that observation and present evidence which suggests that the critical period for plasticity of the rubrospinal tract ends earlier at cervical than at thoracic levels. In addition, we show that most rubrospinal neurons die as a result of axotomy during early stages of the critical period. The opossum was chosen for study because the development of its rubrospinal tract occurs after birth. In one set of experiments the area containing the rubrospinal tract was lesioned at cervical or thoracic levels and after 30 days or more, retrograde transport techniques were used to determine if rubral axons had grown caudal to the lesion. When the lesions were made at rostral cervical levels between estimated postnatal day 26 and maturity, neurons could not be labeled in the contralateral red nucleus by injections of retrograde markers ipsilateral to the lesion and caudal to it. We were not able to obtain adequate survival after cervical lesions made prior to estimated postnatal day 26. When the lesions were made at mid to caudal thoracic levels between estimated postnatal days 19 and 26, neurons could be labeled in the contralateral red nucleus. When comparable lesions were made at estimated postnatal day 40, there was usually a decrease in the number of labeled neurons, and when they were made at estimated postnatal day 54, none was labeled. In selected cases, operated at estimated postnatal day 19, cell counts provided evidence for loss of neurons in the red nucleus contralateral to the lesion. In orthograde transport experiments performed on animals with thoracic lesions of the rubrospinal tract made between estimated postnatal days 18 and 33, rubral axons could be labeled caudal to the lesion, and they seemed to take the most direct route around it. Although they sometimes assumed abnormal positions caudal to the lesion, rubral axons appeared to reach areas of the gray matter appropriate to them. When lesions were made at estimated postnatal day 54 or in older animals, labeled axons could be traced to the lesion site but not caudal to it.(ABSTRACT TRUNCATED AT 400 WORDS)

Evidence for developmental plasticity of the rubrospinal tract. Studies using the North American opossum

Using axonal tracing techniques we have shown that rubral axons are capable of growing around lesions of the rubrospinal tract during early stages of development in the North American opossum and that a critical period for such growth exists. The opossum was employed for study because it is born in a very immature state 12-13 days after conception and the entire development of its rubrospinal tract occurs postnatally.