Tuberculous spondylitis in adults: diagnosis and treatment

A retrospective study of 23 patients with spinal tuberculosis (TB) was conducted, with special attention to the diagnosis and method of treatment. Computerised tomography (CT) was found to be the diagnostic radiological modality of choice. Triple therapy with the new anti-tuberculous drugs and posterior or posteriolateral decompression succeeded in decompressing the cord and eliminating the tuberculous lesion in all cases. The outcome was comparable to series where anterior decompression was adopted. None of the patients required spinal fusion. Erythrocyte sedimentation rate was the most consistent blood test in suggesting the diagnosis and was the best tool for evaluating a patient's response to treatment. The average hospital stay was only 17 days, which speaks favourably for the surgical management of tuberculous spondylitis.     

Sphingosine 1 phosphate induces the chemotaxis of human natural killer cells. Role for heterotrimeric G proteins and phosphoinositide 3 kinases

We have examined the effect of sphingolipids on the chemotaxis of human natural killer (NK) cells. Messenger RNA for Edg-1, Edg-6 and Edg-8 but not Edg-3, are expressed in these cells. Sphingosine 1 phosphate (SPP), dihydro SPP (DHSPP) or the CC chemokine RANTES (CCL5), but not sphingosine induces the chemotaxis of these cells. Pertussis toxin inhibits the chemotaxis induced by these ligands. Permeabilization of NK cells with streptolysin O (SLO) and introduction of blocking antibodies to the heterotrimeric G proteins, showed that Galpha(i2), Galpha(s), Galpha(q/11) or Galpha(13) mediate the chemotaxis of SPP, whereas Galpha(i2), Galpha(o) or Galpha(q/11) mediate the chemotaxis of DHSPP. Galpha(i2), Galpha(o), Galpha(s), Galpha(q/11), Galpha(z) or Galpha(12 )mediates RANTES-induced NK cell chemotaxis. Further analysis showed that phosphoinositide 3 kinase (PI3K) inhibitors wortmannin and LY294002 inhibit NK cell chemotaxis induced by SPP, DHSPP or RANTES. Blocking antibody to PI3Kgamma inhibits the chemotaxis induced by the three ligands, whereas anti-PI3Kbeta was without effect. In contrast, SPP and DHSPP recruit PI3Kbeta isozyme into NK cell membranes, suggesting that although this isoform is not involved in chemotaxis, it is activated by these phospholipids.     

Complete Nucleotide Sequence of the Rice Tungro Spherical Virus Genome of the Highly Virulent Strain Vt6

The complete nucleotide sequence of rice tungro spherical virus (RTSV) strain Vt6, originally from Mindanao, the Philippines, with higher virulence to resistant rice cultivars, was determined and compared with the published sequence for the Philippine-type strain A (RTSV-A-Shen). It was reported that RTSV-A was not able to infect a rice resistant cultivar TKM 6 (10). RTSV-Vt6 and RTSV-A-Shen share 90% and 95% homology at nucleotide and amino-acid levels, respectively. The N-terminal leader sequence of RTSV-Vt6 contained a 39-amino acids-region (positions 65 to 103) which was totally different from that of RTSV-A-Shen; the difference resulted from frame shifting by nucleotide insertions and deletions. To confirm the amino-acid sequence differences of the leader polypeptide, the same region was cloned and sequenced using a newly obtained variant of RTSV-type 6, which had been collected in the field of IRRI, and seven field isolates from Mindanao, the Philippines. Since all the sequences of the target region are identical to that of the Vt6 leader polypeptide, the sequence difference in the leader region seems not to correlate with the virulence of Vt6.     

Lysophosphatidic acid induces human natural killer cell chemotaxis and intracellular calcium mobilization

We have investigated the effects of the bioactive lipid lysophosphatidic acid (LPA) on several functions of activated human natural killer (NK) cells. Flow cytometric and immunoblot analyses show that these cells express LPA(1, )LPA(2) and LPA(3). LPA but not its precursor phosphatidic acid (PA) induces the chemotaxis of NK cells, an activity that is inhibited by prior treatment of the cells with pertussis toxin (PTX). In addition, LPA induces the mobilization of intracellular calcium, an effect that is markedly inhibited by PTX, but is not inhibited by the addition of EGTA. PA also induces calcium flux in NK cells, but with much lower efficacy than LPA. Cross-desensitization experiments demonstrate that LPA and PA utilize different receptors. Moreover, LPA or PA but not sphingosine 1-phosphate, enhances IFN-gamma secretion by activated NK cells. Our results may shed some light on the findings that activated NK cells are found at the sites of tumor growth.     

Genetic composition and complexity of virus populations at tungro-endemic and outbreak rice sites

Summary.  We have recently demonstrated the geographic isolation of rice tungro bacilliform virus (RTBV) populations in the tungro-endemic provinces of Isabela and North Cotabato, Philippines. In this study, we examined the genetic structure of the virus populations at the tungro-outbreak sites of Lanao del Norte, a province adjacent to North Cotabato. We also analyzed the virus populations at the tungro-endemic sites of Subang, Indonesia, and Dien Khanh, Vietnam. Total DNA extracts from 274 isolates were digested with EcoRV restriction enzyme and hybridized with a full-length probe of RTBV. In the total population, 22 EcoRV-restricted genome profiles (genotypes) were identified. Although overlapping genotypes could be observed, the outbreak sites of Lanao del Norte had a genotype combination distinct from that of Subang or Dien Khanh but a genotype combination similar to that identified earlier from North Cotabato, the adjacent endemic province. Sequence analysis of the intergenic region and part of the ORF1 RTBV genome from randomly selected genotypes confirms the geographic clustering of RTBV genotypes and, combined with restriction analysis, the results suggest a fragmented spatial distribution of RTBV local populations in the three countries. Because RTBV depends on rice tungro spherical virus (RTSV) for transmission, the population dynamics of both tungro viruses were then examined at the endemic and outbreak sites within the Philippines. The RTBV genotypes and the coat protein RTSV genotypes were used as indicators for virus diversity. A shift in population structure of both viruses was observed at the outbreak sites with a reduced RTBV but increased RTSV gene diversity. Accepted April 28, 2000 Received November 26, 1999     

Heritability and clinical features of multigenerational families with obsessive-compulsive disorder and hoarding.

To date, only one complete genome screen for obsessive-compulsive disorder (OCD) has been published. That study identified a region of suggestive linkage (maximum lod score of 2.25) with a relatively small sample size (N = 56; 27 with OCD). Additional complete genome screens are needed to confirm this finding and identify other regions of linkage. We present the clinical characteristics and power to detect linkage of 11 multigenerational families with OCD and hoarding (N = 92; 44 with OCD), as well as heritability estimates for several quantitative traits. Families with at least two individuals with OCD were identified through probands with childhood-onset OCD. Expected lod scores were calculated for simulated genetic marker data under an additive and two dominant models assuming a dense SNP marker map. All affected individuals had an early age of onset (18 or younger). Hoarding was present in 46% of subjects. Obsessive-compulsive symptoms and hoarding were highly heritable. The maximum mean expected lod score was 3.31 for OCD and 1.39 for hoarding. We found reasonable power to detect regions of interest (lod = 2) for OCD in these families, but will need to expand our family collection to have adequate power to detect regions of interest for hoarding.     

In vivo significance of ICAM-1--dependent leukocyte adhesion in early corneal angiogenesis

PURPOSE: Numerous investigations have stressed the significance of leukocytes in early angiogenesis. Leukocytes invade the cornea, and the location of their extravasation corresponds to the site of vessel ingrowth. The interactions between leukocytes and vascular endothelium are mediated by various proteins, including adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1). In this study, the role of ICAM-1 during early corneal angiogenesis was evaluated in vivo. METHODS: Corneal neovascularization was induced in New Zealand White rabbits by use of intrastromal pellets containing 750 ng vascular endothelial growth factor (VEGF). The fluorescent dye rhodamine 6G was used to stain leukocytes in vivo. Leukocyte adhesion and vessel growth were quantified in vivo by high-resolution fluorescence angiography. To inhibit ICAM-1 interactions a microemulsion containing anti-ICAM-1 antibody was applied topically. RESULTS: Limbal vessels showed increased leukocyte adhesion 24 hours after pellet implantation: The number of rolling and sticking leukocytes was significantly increased compared with the number in control animals (P < 0.01). Treatment with anti-ICAM-1 antibody resulted in reduced leukocyte sticking and increased leukocyte rolling. The area covered by new blood vessels was significantly diminished in eyes treated with anti-ICAM-1 (P < 0.05). CONCLUSIONS: The results support the hypothesis that ICAM-1-mediated leukocyte adhesion is a key event in early angiogenesis. This model may serve for investigation of the significance of adhesion molecules by in vivo observation and quantification.