New aspects in the diagnosis of intervertebral disk displacement of the upper lumbar spine with special reference to magnetic resonance tomography

A report is presented on two patients who received surgery on a disc prolapse between the lumbar vertebrae 4 and 5 as treatment for compression of the fifth lumbar root, but in whom the clinically relevant disc prolapse was located higher (lumbar vertebrae 1/2 or thoracic vertebra 12/lumbar vertebra 1). Magnetic resonance tomography made a major contribution to the later diagnosis of the high disc prolapses. Besides precise localization of the lesion, MRT made it easier to understand why such a high disc prolapse can cause a compression syndrome of the fifth lumbar root.     

Ruptured petrous carotid aneurysm presenting with otorrhagia and epistaxis.

Aneurysm formation and rupture within the petrous internal carotid artery (ICA) is an extremely rare occurrence with approximately 10 such cases in the literature. Etiologies of petrous ICA aneurysms include atherosclerosis, closed head trauma, iatrogenic injury during mastoid surgery, chronic middle ear infections, and congenital causes. Therapeutic options include carotid artery ligation, aneurysm resection with or without reconstruction, and radiographically controlled vessel occlusion. The case of a patient who presented with otorrhagia, epistaxis, and transient focal neurologic signs due to a ruptured petrous ICA aneurysm is presented. The incidence, etiology, and anatomy of these aneurysms is reviewed, and the various tests for determining adequacy of collateral cerebral blood flow are described. Factors that affect the selection of surgical versus radiologic control of these lesions are also discussed.     

Chemiluminescent response to pathogenic organisms: normal human polymorphonuclear leukocytes

Chemiluminescence (CL) is a sensitive indicator of phagocytosis and intracellular killing; however, little is known of the normal CL response by human polymorphonuclear leukocytes to different pathogenic microorganisms. We investigated the luminol-enhanced CL response of normal polymorphonuclear leukocytes to a number of common bacterial pathogens and two yeasts. We analyzed the CL response to viable and heat-killed microorganisms at 25 and 37 degrees C. The CL response to all microorganisms was greater and more rapid at 37 degrees C. Variable responses were observed with viable and heat-killed microorganisms; some were unaffected, whereas other demonstrated reduced CL. Each microorganism caused a reproducible response pattern, which could be placed into two general categories. In the first category were those which caused a rapid exponential rise and decay in CL: Enterobacter cloacae, Salmonella typhimurium, Shigella flexneri, Staphylococcus aureus, Candida albicans, and zymosan. In the second category were those which rose slowly over a longer time course to a poorly defined peak: Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Streptococcus pyogenes. The CL response also reflected serum opsonic activity. The effect of inactivated complement, factor B, and removal of specific antibody were investigated. Increasing the concentration of zymosan gave a proportional rise in peak CL; however, a strain of E. coli caused a variation in peak time rather than peak height. Different CL kinetics were shown for three strains of K. pneumoniae, possibly a result of each having different membrane or cell wall characteristics. This study defines the nature and factors affecting the normal CL response to a variety of common pathogenic microorganisms.     

Antibody penetration of viable human cells. I. Increased penetration of human lymphocytes by anti-RNP IgG.

Antibody penetration of viable cells and interaction with intracellular antigens may have major consequences for immunopathological processes in connective tissue diseases. We have reported previously that antibody can penetrate viable human lymphocytes. To assess further the role of antinuclear antibodies in this process, peripheral blood lymphocytes (PBMC) were incubated with FITC-conjugated IgG fractions from sera containing anti-RNP (anti-RNP IgG), Ro(SS-A), La(SS-B) and dsDNA antibodies and control sera for 24 h. Using crystal violet to quench cell surface staining, intracellular fluorescence of viable lymphocytes was quantified on the flow cytometer. It was noted that anti-RNP IgG entered 46.4 +/- 7.2% of lymphocytes which was significantly higher than anti-Ro(SS-A) (29.9 +/- 4.1%, P less than 0.05), La(SS-B) (22.0 +/- 7.5%, P less than 0.01) IgG and control IgG (28.8 +/- 2.1%, P less than 0.05) and not statistically different from anti-dsDNA IgG (32.6 +/- 14.3%). Inhibition experiments showed that the increased number of cells penetrated by anti-RNP IgG was a specific process. Time-course studies showed that anti-RNP IgG entry into cells was different from pooled control IgG. With anti-RNP IgG, positive-staining lymphocytes gradually increased in number from 12 to 24 h incubation, whilst with pooled control IgG, the peak was reached within 5 min. Dual staining experiments suggested that whereas both anti-RNP IgG and pooled control IgG entered B and NK cells, anti-RNP IgG also entered T cells. Using IgG F(ab')2 and Fc fragments from either anti-RNP IgG or pooled control IgG to compete with their FITC-conjugated counterparts indicated that the entry of anti-RNP IgG into-viable cells appeared to involve both F(ab')2 and Fc fragments, and pooled control IgG depended exclusively on the Fc portion of IgG. Further investigation by incubating anti-RNP IgG with 35S-methionine-labelled monocyte-depleted PBMC (MD-PBMC) suggested that anti-RNP IgG might react with the corresponding antigens either on the cell surface or within the cytoplasm.     

Inhibition of the human ether-a-go-go-related gene (HERG) potassium channel by cisapride: affinity for open and inactivated states.

1 Cisapride is a prokinetic agent which has been associated with QT prolongation, torsades de pointes and cardiac arrest. The cellular mechanism for these observations is high affinity blockade of IKr (encoded by HERG). 2 In a chronic transfection model using CHO-K1 cells, cisapride inhibited HERG tail currents after a step to +25 mV with similar potency at room and physiological temperatures (IC50 16. 4 nM at 20-22 degrees C and 23.6 nM at 37 degrees C). 3 Channel inhibition exhibited time-, voltage- and frequency-dependence. In an envelope of tails test, channel blockade increased from 27+/-8% after a 120 ms depolarizing step to 50+/-4% after a 1.0 s step. These findings suggested affinity for open and/or inactivated channel states. 4 Inactivation was significantly accelerated by cisapride in a concentration-dependent manner and there was a small (-7 mV) shift in the voltage dependence of steady state inactivation. 5 Channel blockade by cisapride was modulated by [K+]o, with a 26% reduction in the potency of channel blockade when [K+]o was increased from 1 to 10 mM. 6 In conclusion, HERG channel inhibition by cisapride exhibits features consistent with open and inactivated state binding and is sensitive to external potassium concentration. These features may have significant clinical implications with regard to the mechanism and treatment of cisapride-induced proarrhythmia.     

MIC-1 serum level and genotype: associations with progress and prognosis of colorectal carcinoma.

PURPOSE: Macrophage inhibitory cytokine-1 (MIC-1) is a divergent member of the tumor growth factor beta (TGF-beta) superfamily. Several observations suggest that it plays a role in colorectal carcinoma (CRC). In particular, MIC-1 is markedly up-regulated in colorectal cancers as well as in premalignant adenomas. This study examines the relationship of serum MIC-1 levels and genotypes to clinical and pathologic features of colonic neoplasia. Experimental Design: We confirmed the presence of MIC-1 in CRC tissue and the cell line CaCo-2. The normal range for serum MIC-1 levels was defined in 260 healthy blood donors, and the differences between normal subjects and 193 patients having adenomatous polyps or CRC were then determined. In a separate cohort of 224 patients, we evaluated the relationship of MIC-1 serum level and genotype to standard tumor parameters and outcome measures. RESULTS: MIC-1 was expressed in CRC tissue and the cancer cell line CaCo-2. There was a progressive increase in serum MIC-1 levels between normal individuals [mean (M) = 495 pg/ml, SD = 210), those with adenomatous polyps (M = 681 pg/ml, SD = 410), and those with CRC (M = 783 pg/ml, SD = 491)]. Serum MIC-1 level was correlated with the extent of disease so that the levels were higher in patients with higher Tumor-Node-Metastasis stage. There were significant differences in time to relapse and overall survival between subjects with different MIC-1 levels and genotypes. CONCLUSIONS: This study identifies a strong association between MIC-1 serum levels and neoplastic progression within the large bowel. We suggest that the measurement of serum MIC-1 levels and determination of MIC-1 genotype may have clinical use in the management of patients with CRC.     

Fatal meningoencephalitis due to Bacillus anthracis

Abstract: We report the first case of fatal anthrax meningoencephalitis in Hong Kong over the past 60 years. A 13 year-old boy presented with right lower quadrant pain, diarrhoea and progressive headache. Lumbar puncture yielded gram positive bacilli initially thought to be Bacillus cereus, a contaminant. He was treated with ampicillin and cefotaxime, but died 3 days after hospitalization. The organism isolated from blood and cerebrospinal fluid was later identified as Bacillus anthracis.     

Escherichia coli tetracycline efflux determinants in relation to tetracycline residues in chicken

ObjectiveTo screen for Escherichia coli (E. coli) resistant to tetracycline, followed by identification of tet efflux genes by polymerase chain reaction (PCR). In addition, detection of tetracycline residues in chicken livers and kidneys were conducted using high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS).MethodsStrains of E. coli were isolated from samples of chicken colon and screened for tetracycline resistance. Tetracycline genes conferring resistance (Tc^r) were detected by polymerase chain reaction (PCR). Most of the isolates were resistant to tetracycline (97.9%).ResultsPCR analysis indicated that Tc^r E. coli R-plasmids contained tet(A), tet(B) and a combination of both efflux genes. None of the isolates contained other efflux tet genes tet (C, D, E and Y). High performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS), a sensitive technique, was used to detect residues of chlortetracycline (CTC), oxytetracycline (OTC), doxycycline (DC) in chicken livers and kidneys. The samples containing tetracycline residues were at 0.13-0.65 pg/μL levels.ConclusionsTetracycline and other antibiotics are commonly used in the poultry and meat production industry for prevention of microbial infections. Multiple antibiotic resistant bacteria in Oman have increased to alarming levels, threatening public health, domestic and may have adverse effect on environment.