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Biomedical subjects

V Ng

Publications and source records attributed to V Ng.

At least 37 records · Page 2Linked to original sources
PubMed2001

Renal dysfunction in workers exposed to inorganic lead.

INTRODUCTION: We studied the relationship between renal dysfunction and occupational lead exposure in a local factory. MATERIALS AND METHODS: A cross-sectional study with a cohort component was conducted with 55 male workers of a factory producing PVC stabilisers as subjects. Workers from this factory have been followed up with 6-monthly blood lead measurements since 1982. Two indices of overall lead exposure, i.e. the number of times a worker's blood lead exceeded 40 micrograms/dL (PbB40) and cumulative blood lead index (PbBint), were obtained from this data. Recent blood lead concentration (PbB) was measured. 4-hour creatinine clearance and various other urinary and serum markers of renal dysfunction were used as effect indices. RESULTS: There was no relationship between PbB and any of the renal markers. However, creatinine clearance decreased significantly (P < 0.001) with increasing PbB40 and PbBint after adjustment for age and smoking habits. Urinary albumin (Ualb), urinary alpha-1 microglobulin (U alpha 1m), urinary beta-2 microglobulin (U beta 2m) and urinary retinol-binding protein (URBP) increased significantly with both increasing PbB40 and PbBint. Total urinary activity of N-acetyl-beta-D-glucosaminidase (NAG-T) and its heat-stable isoenzyme (NAG-B) increased significantly with increasing PbB40. A significant difference in renal parameters occurred when PbB40 was 1 or more. CONCLUSIONS: We have found a positive association between overall lead exposure and renal dysfunction. The renal parameters were significantly higher among those who had at least one episode of blood lead above 40 micrograms/dL. Our findings also strengthen the case for the use of Ualb, U alpha 1m, U beta 2m, URBP, NAG-T and NAG-B as early markers of lead nephropathy.

Adult↗
PubMed2000

Role of the cell wall phenolic glycolipid-1 in the peripheral nerve predilection of Mycobacterium leprae.

The cell wall of pathogenic mycobacteria is abundant with complex glycolipids whose roles in disease pathogenesis are mostly unknown. Here, we provide evidence for the involvement of the specific trisaccharide unit of the phenolic glycolipid-1 (PGL-1) of Mycobacterium leprae in determining the bacterial predilection to the peripheral nerve. PGL-1 binds specifically to the native laminin-2 in the basal lamina of Schwann cell-axon units. This binding is mediated by the alpha(2LG1, alpha2LG4, and alpha2LG5 modules present in the naturally cleaved fragments of the peripheral nerve laminin alpha2 chain, and is inhibited by the synthetic terminal trisaccharide of PGL-1. PGL-1 is involved in the M. leprae invasion of Schwann cells through the basal lamina in a laminin-2-dependent pathway. The results indicate a novel role of a bacterial glycolipid in determining the nerve predilection of a human pathogen.

Animals↗
PubMed2000

Tear proteins of normal young Hong Kong Chinese.

BACKGROUND: Analysis of tear proteins is of diagnostic value for abnormal ocular conditions such as dry eye syndrome. Many studies of tear proteins have been performed on Caucasian subjects. However, little is known about these proteins in Chinese eyes. METHODS: The total tear protein concentrations of 30 normal young Hong Kong Chinese were determined by the Bradford method and the modified Lowry method. Bovine serum albumin (BSA) and bovine immunoglobulin G (IgG) were both used as standards for each method. The tear protein patterns were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the concentrations of major tear proteins were quantified by scanning densitometry after SDS-PAGE. RESULTS: The mean +/- SD total tear protein concentrations determined by the Bradford method, using BSA and IgG as standards, were 6.05 +/- 1.58 mg/ml and 11.48 +/- 2.32 mg/ml respectively. The values determined by the modified Lowry method, using the same two standards, were 9.66 +/- 2.03 mg/ml and 7.53 +/- 1.80 mg/ml respectively. The mean +/- SD concentrations of major tear proteins were 2.73 +/- 0.82 mg/ml for lactoferrin, 0.021 +/- 0.028 mg/ml for human serum albumin, 2.89 +/- 0.88 mg/ml for tear-specific prealbumin and 2.46 +/- 0.44 mg/ml for lysozyme. CONCLUSION: The results of total tear protein concentrations indicated that values obtained from different methods and different standards were not comparable. The tear protein patterns of our subjects were qualitatively similar to those reported for Caucasian subjects. However, the concentrations of the major proteins of our subjects were not in accordance with those reported previously. The main reason may be the large variability of method used.

Adolescent↗
PubMed2000

The relationship between total tear protein concentrations determined by different methods and standards.

BACKGROUND: It is known that the values of total protein concentration (TPC) of human tears obtained by different methods/standards vary considerably. The variations are due to differences in reactivity of proteins to the methods used. The aim of this study was to investigate the relationships and agreements between TPC values obtained by different methods/standards. METHODS: Two experiments were conducted. In experiment 1, 30 normal subjects were recruited and their TPC were determined by the Bradford and the modified Lowry methods, with bovine serum albumin and bovine immunoglobulin G as standards. The relationships (equations) between TPC values obtained by different methods/standards were determined. In experiment 2, another 15 normal subjects were recruited and the TPC were measured as in experiment 1. Measured values of TPC using different methods/standards were compared with their respective values calculated from the equations defined in experiment 1. The agreement and the reliability between the measured and the calculated values were investigated. RESULTS: Experiment 1 showed that the TPC obtained by different methods/standards were strongly correlated to one another, and their relationships can be defined by linear equations. In experiment 2, the measured and the calculated values, using the equations defined in experiment 1, showed good agreement and reliability. This indicates that TPC obtained by one method/standard can be used to estimate the value(s) that would be obtained if another method/standard were used using the equation(s) found in experiment 1. CONCLUSION: The correlations between TPC values obtained by different methods/standards were strong. Our results also indicated good agreement and reliability between measured and calculated TPC values. Therefore, values obtained by different methods/standards are interchangeable using the appropriate equations.

Adolescent↗
PubMed2000

Variability of tear protein levels in normal young adults: between-day variation.

BACKGROUND: An adequate knowledge of physiological variation is important for valid comparative studies of tear proteins. The aim of this study was to investigate the between-day variation of the human tear protein levels, including the total protein concentration (TPC) and the levels of major protein fractions. Two sampling methods, the yawn and the eye-flush methods, were used and compared. METHODS: TPC was determined by the Bradford method. The major protein fractions were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and their levels were determined by scanning densitometry after SDS-PAGE. The tear protein levels were monitored for 3 days. RESULTS: The between-day differences in the levels of TPC and the individual protein fractions were not statistically significant in either sampling method, but the variations of some proteins were large and would be clinically significant. Different variations were observed in different proteins. The variations in serum albumin were large, up to 61% and 113% in the yawn and eye-flush methods respectively. The variations in lactoferrin, tear-specific prealbumin and lysozyme were relatively small in the yawn method. The variations in protein levels obtained by the eye-flush method were generally higher than by the yawn method. CONCLUSION: Although the between-day differences in tear protein levels were not statistically significant, the variations in some proteins would be large in magnitude. The variability of tear protein levels obtained by the eye-flush method was larger than that by the yawn method. Therefore, caution should be taken if the eye-flush method is used for sampling tears for quantitative analysis of tear proteins, although it is easier to collect tear samples using this method. The results will be useful to exclude normal variation in tear protein levels when comparing pre- and post-therapeutic tear protein levels in eyes treated for tear-related abnormalities.

Adult↗
PubMed2000

Tumor Burden Assessment with Positron Emission Tomography with

Objective: In patients with advanced cancer, total tumor burden affects the likelihood of tumor response and has important implications for prognosis. The aim of this study was to select the optimum 2-[F-18]fluoro-2-deoxy-D-glucose-positron emission tomography (FDG PET) tumor uptake parameter to accurately measure tumor burden in advanced metastatic renal cell cancer, in comparison with volumes measured with computed tomography (CT), as a reference test.Materials and Methods: Six patients with metastatic renal cell carcinoma measurable on CT were studied. CT and FDG PET scans were carried out on all patients within 4 weeks prior to their entry into a phase I-II radioimmunotherapy trial. CT-based evaluation of disease extent (tumor volume) and 4 PET-based measurements (standardized uptake value[SUVmax], SUVav, volume, and total lesion glycolysis [TLG]) were performed independently by a radiologist (VN) and a nuclear medicine physician (TA). The degree of correlation between conventional (CT) extent of disease and parameters describing tumor concentration of FDG was then determined.Results: Fifty-seven CT-measurable metastatic lesions in lung, abdomen, and scalp were evaluated in 6 patients. There was a high correlation between CT and FDG PET volume estimates for lesions greater than 5 cm(3) in size. However, a PET-derived parameter that embodies both FDG uptake and lesion size, the TLG, correlated better with CT-derived tumor volume than did FDG PET volume alone.Conclusion: Using CT volume as a gold standard, the optimal PET-based estimate of total tumor burden in patients with metastatic renal cancer is the sum over all lesions of the total lesion glycolysis.

Journal Article↗
PubMed2000

Clinical performances of two disposable soft contact lenses of different materials on Hong Kong-Chinese.

Dryness due to contact lens wear and poor wetting of contact lenses among contact lens wearers is a common observation and contact lens manufacturers have introduced new, better quality soft lens materials that are claimed to be more deposit resistant, and/or dehydration resistant. The purpose of this study was to evaluate and compare the clinical performance of Hydron ActiSoft 60 section sign, made of a new material (HyGMAtrade mark) which is claimed to be dehydration resistant with excellent wettability, with ActiFresh 400, made of conventional non-ionic hydrogel material. The experiment was conducted as a double-masked, randomised, cross-over study. Clinical assessment included pre-lens non-invasive tear break up time (PL-NITBUT), logMar visual acuity and contrast sensitivity (CS). Corneal staining, if any, was recorded at each visit. Subjective ratings in regard to dryness, grittiness, lens awareness, vision, comfort, handling (removal), handling (cleaning) and the overall preference of each lens type were obtained at the end of 3 (Phase A) and 6 months' (Phase B) wear. Twenty-eight subjects successfully completed the study. In Phase A, no significant differences were found in both baseline PL-NITBUT and PL-NITBUT after wearing the same lenses for 1 month between the two lens types. In phase B, baseline PL-NITBUT for ActiFresh 400 was significantly shorter than that for ActiSoft 60. However, after 1 month of wear, the difference in PL-NITBUT between the two lens types was no longer significant. PL-NITBUT was significantly reduced after 1 month's wear for both ActiSoft 60 and Actifresh 400, and in both Phase A and Phase B. The two lens types provided comparable logMAR visual acuity, and there was no significant differences in CS (Pelli Robson) between spectacle lens correction (equivalent spheres) and either lens type. The incidence of corneal epithelial staining was significantly higher and more severe with ActiFresh 400 than with ActiSoft 60, both in Phase A and Phase B. Statistically, there were no significant differences in the scores to the set of questions listed in the questionnaire between the two lens types, except for lens awareness and lens handling. Of the subjects having a preference for one lens, more subjects preferred ActiSoft 60 than ActiFresh 400. In terms of overall preference of the two lens types, at the end of Phase A, 50% of the subjects preferred ActiSoft 60 while only 30% preferred ActiFresh 400, the remaining 20% had no preference. However, by the end of Phase B, preferences for ActiSoft 60 and ActiFresh 400 were comparable. This appeared to be due mainly to the ease of lens handling of the latter.

Journal Article↗
PubMed2000

Quantitative and cost comparison of ultrasensitive human immunodeficiency virus type 1 RNA viral load assays: Bayer bDNA quantiplex versions 3.0 and 2.0 and Roche PCR Amplicor monitor version 1.5.

Quantification of human immunodeficiency virus type 1 (HIV-1) RNA as a measure of viral load has greatly improved the monitoring of therapies for infected individuals. With the significant reductions in viral load now observed in individuals treated with highly active anti-retroviral therapy (HAART), viral load assays have been adapted to achieve greater sensitivity. Two commercially available ultrasensitive assays, the Bayer Quantiplex HIV-1 bDNA version 3.0 (bDNA 3.0) assay and the Roche Amplicor HIV-1 Monitor Ultrasensitive version 1.5 (Amplicor 1.5) assay, are now being used to monitor HIV-1-infected individuals. Both of these ultrasensitive assays have a reported lower limit of 50 HIV-1 RNA copies/ml and were developed from corresponding older generation assays with lower limits of 400 to 500 copies/ml. However, the comparability of viral load data generated by these ultrasensitive assays and the relative costs of labor, disposables, and biohazardous wastes were not determined in most cases. In this study, we used matched clinical plasma samples to compare the quantification of the newer bDNA 3.0 assay with that of the older bDNA 2.0 assay and to compare the quantification and costs of the bDNA 3.0 assay and the Amplicor 1.5 assay. We found that quantification by the bDNA 3.0 assay was approximately twofold higher than that by the bDNA 2.0 assay and was highly correlated to that by the Amplicor 1.5 assay. Moreover, cost analysis based on labor, disposables, and biohazardous wastes showed significant savings with the bDNA 3.0 assay as compared to the costs of the Amplicor 1.5 assay.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Psychological trauma, physical health and somatisation.

The aim of this review is to examine the relationship between trauma, physical health and somatisation. A search was made on the Procite Database at the Department of Psychiatry at the Uniformed Services University of the Health Sciences for research articles with the following key words: posttraumatic stress disorder, somatisation, trauma (the Procite Database holds more than 15,000 articles related to trauma and disaster). A review of the current research findings show a link between prior exposure to traumatic events (such as war, disaster, motor vehicles and industrial accidents, crime and sexual assault, domestic violence and child abuse) and subsequent physical heath and medical care utilisation. Possible mechanisms and conceptualisations which may explain the association between trauma and physical health, such as high-risk health behaviours, neurobiology, alexithymia and culture are discussed. Because traumatised persons show high medical utilisation, good screening, thorough assessment, empirically-based treatment and appropriate referral of such patients are essential.

Affective Symptoms↗
PubMed1999

A 21-kDa surface protein of Mycobacterium leprae binds peripheral nerve laminin-2 and mediates Schwann cell invasion.

Nerve damage is the hallmark of Mycobacterium leprae infection, which results from M. leprae invasion of the Schwann cell of the peripheral nervous system. We have recently shown that the laminin-2 isoform, specially the G domain of laminin alpha2 chain, on the Schwann cell-axon unit serves as an initial neural target for M. leprae. However, M. leprae surface molecules that mediate bacterial invasion of peripheral nerves are entirely unknown. By using human alpha2 laminins as a probe, a major 28-kDa protein in the M. leprae cell wall fraction that binds alpha2 laminins was identified. After N-terminal amino acid sequence analysis, PCR-based strategy was used to clone the gene that encodes this protein. Deduced amino acid sequence of this M. leprae laminin-binding protein predicts a 21-kDa molecule (ML-LBP21), which is smaller than the observed molecular size in SDS/PAGE. Immunofluorescence and immunoelectron microscopy on intact M. leprae with mAbs against recombinant (r) ML-LBP21 revealed that the protein is surface exposed. rML-LBP21 avidly bound to alpha2 laminins, the rG domain of the laminin-alpha2 chain, and the native peripheral nerve laminin-2. The role of ML-LBP21 in Schwann cell adhesion and invasion was investigated by using fluorescent polystyrene beads coated with rML-LBP21. Although beads coated with rML-LBP21 alone specifically adhered to and were ingested by primary Schwann cells, these functions were significantly enhanced when beads were preincubated with exogenous alpha2 laminins. Taken together, the present data suggest that ML-LBP21 may function as a critical surface adhesin that facilitates the entry of M. leprae into Schwann cells.

Adhesins, Bacterial↗
PubMed1999

Regulation of anion secretion by cyclo-oxygenase and prostanoids in cultured epididymal epithelia from the rat.

1. The role of cyclo-oxygenase (COX) in the regulation of anion secretion (measured as short- circuit current, Isc) in cultured epididymal epithelia from immature rats was investigated. 2. COX inhibitors attenuated the increase of anion secretion caused by bradykinin (LBK) but had no effect on that caused by PGE2, suggesting that prostaglandin synthesis mediates the secretory response of the tissues to LBK. 3. The apparent IC50 values for indomethacin, piroxicam and L-745,337 in inhibiting the LBK-induced Isc were 0.14, 1.34 and 15.7 microM, respectively. This order of potency: indomethacin > piroxicam > L-745,337 >> DFU suggests the involvement of the COX-1 isozyme in the mediation of the secretory response to LBK. 4. Among the COX products (prostaglandins, thromboxane and prostacyclins) tested, only PGE2 and, to a much lesser extent, PGF2alpha stimulated anion secretion by cultured rat epididymal epithelia. 5. The effect of PGE2 was mimicked by 11-deoxyl PGE1, a specific prostaglandin E (EP)2/4 receptor agonist, but not by sulprostone, a specific EP1/3 receptor agonist, indicating that cyclic AMP-coupled EP2/4 receptors are involved in the LBK-stimulated anion secretion. 6. A reverse transcriptase-polymerase chain reaction study detected the expression of COX-1 and COX-2 mRNA in intact rat epididymis and in cultured epididymal epithelia. The expression of COX-1 mRNA was reduced by LBK by 44 %. 7. Immunohistochemical studies demonstrated the presence of COX-1 immunoreactivity in the basal cells of the intact rat epididymis. By comparison, COX-2 immunoreactivity was detected in the apical pole of the principal cells. 8. The role of COX in the formation of the epididymal microenvironment and the implication of long term administration of non-steroidal anti-inflammatory drugs (NSAIDs) on male fertility are discussed.

Animals↗
PubMed1999

Differential increase in Fos immunoreactivity in hypothalamic and septal nuclei by arginine8-vasopressin and desglycinamide9-arginine8-vasopressin.

Subcutaneous or intracerebroventricular injection of either arginine8-vasopressin or desglycinamide9-arginine8-vasopressin has been shown to facilitate memory, reduce or reverse the effects of amnesic drugs, and maintain tolerance to some effects of ethanol. These actions of vasopressin (and, by inference, of desglycinamide9-arginine8-vasopressin) are mediated by vasopressin V1 receptors in brain, via a c-fos-dependent mechanism, but the receptors at which the desglycinamide analog acts have not been identified. The precise central sites are also not known, but evidence of several types suggested the anterior hypothalamus and septum as probable loci of vasopressin action. In the present work, this question was studied by immunocytochemistry, using antibodies against Fos and Fos-like proteins. The numbers of Fos-immunoreactive nuclei were counted in several related brain regions and structures, after administration of arginine8-vasopressin, des-Gly9-[Arg8]-vasopressin or saline. A subcutaneous injection of vasopressin, but not of saline, enhanced Fos expression in the paraventricular, supraoptic and suprachiasmatic nuclei of the hypothalamus, but the desglycinamide analog stimulated Fos expression only in the suprachiasmatic nucleus. Vasopressin injection significantly increased the number of Fos-immunoreactive cells in the intermediate lateral septum, medial septum, and dorsal and ventral divisions of the lateral septum. In contrast, the desglycinamide analog increased the numbers of Fos-immunoreactive cells in the dorsal and intermediate portions of the lateral septum, but caused no change in the medial septum, and a decrease in the ventral portion of the lateral septum. Increased Fos expression was also found in the subfornical organ after subcutaneous injection of either vasopressin or the desglycinamide analog. Double labeling with antibodies against Fos protein and against vasopressin revealed that most of the vasopressin-induced Fos-immunoreactive cells in the supraoptic, paraventricular and suprachiasmatic hypothalamic nuclei are also vasopressin immunoreactive, i.e. they are vasopressin-producing neurons. These findings suggest that a circuit involving V1 receptors in the subfornical organ, connecting fibres to the suprachiasmatic nucleus, and vasopressinergic projections from the suprachiasmatic nucleus to the lateral septum, may play a central role in mediating the actions of both vasopressin and its desglycinamide analog in the maintenance of ethanol tolerance.

Animals↗
PubMed1999

Are salivary immunoglobulin A and lysozyme biomarkers of stress among nurses?

Salivary immunoglobulin A (IgA) and lysozyme have been studied as possible biomarkers of stress. This study examined the stress levels among female nurses in various units and the relationship between these stress levels and salivary IgA and lysozyme secretion. One hundred ninety-five (43%) of 457 eligible female nurses from surgical wards/operating theaters (SURG), medical wards (MED), and outpatient clinics/day-surgery theaters (OPD) completed a self-administered questionnaire. From this group of 195 nurses, 124 provided a salivary sample accumulated over 5 minutes. Stress levels were assessed with a ten-point Stress Assessment Score (SAS) for Asians and a direct question on perceived life stress. Enzyme-linked immunosorbent assay and lyso-plate methods were used to determine salivary IgA and lysozyme levels. Forty-five percent of SURG, 35% of MED, and 17% of OPD nurses scored at least four points on the SAS. SURG nurses had the lowest IgA secretion (geometric mean; 95% confidence interval [CI]) rates (43 micrograms/min; 36 to 51 micrograms/min). The other groups had significantly higher salivary IgA secretion rates: MED (96 micrograms/min; 80 to 116 micrograms/min) and OPD (77 micrograms/min; 60 to 98 micrograms/min) Findings for salivary lysozyme (microgram/min) were similar; SURG (9 micrograms/min; 6 to 13 micrograms/min) MED (19 micrograms/min; 12 to 28 micrograms/min) and OPD (16 micrograms/min; 9 to 28 micrograms/min). The salivary IgA (Spearman's r = -0.22, P = 0.01) but not the lysozyme (Spearman's r = -0.01, P = 0.9) secretion rate correlated negatively with SAS. Nurses working in various units under different conditions experienced dissimilar levels of stress. Salivary IgA, but not lysozyme, correlated inversely with self-reported levels of stress. It may thus be a potential biomarker in future studies on stress.

Adult↗
PubMed1999

Lesion volume, lesion location, and outcome after middle cerebral artery territory stroke.

AIM: To investigate the relation between lesion volume, lesion location, and clinical outcome in children with infarction in the territory of the middle cerebral artery (MCA). PATIENTS AND METHODS: Children with MCA territory infarcts were selected retrospectively from a database of children with ischaemic stroke. Lesion volumes were expressed as a percentage of the supratentorial intracranial volume and were categorised as "small", "moderate", or "large". Lesion location was categorised as cortical or purely subcortical. Outcome was ascertained by parental questionnaire and was categorised as "good" or "poor". RESULTS: 38 patients were identified (median age 6 years); 21 patients had lesions that involved cortical tissue. Outcome was good in 12 cases and poor in 26 cases (including 2 children who died). Although there was no significant effect of lesion size or lesion location on outcome for the group as a whole, all children who had infarcted more than 10% of intracranial volume had a poor outcome. Of note, some children with small subcortical lesions had pronounced residual deficits. CONCLUSIONS: Although the outcome after a small infarct in the MCA territory is variable and unpredictable, infarction of more than 10% of intracranial volume is universally associated with a poor outcome. Characterisation of lesion volume and topography might be helpful in identification of such children for participation in future trials of treatments for acute stroke.

Adolescent↗
PubMed1998

The value of ultrafast computed tomography in the investigation of pediatric chest disease.

Ultrafast computed tomography (CT) can be performed in almost all children with little or no sedation. The benefit has to be balanced against financial cost and radiation dose. Since observing a steady increase in numbers of scans performed, we analyzed the contribution to management of 106 pediatric chest CT scans performed over a 12-month period. Forty-eight of 106 yielded a positive diagnosis and a further 43/106 provided clearly useful information. CT was most useful in children with chronic productive cough (21/48 scans showed bronchiectasis) and suspected interstitial lung disease. It was least useful in the preoperative assessment of empyema complicating community-acquired pneumonia (0/11 scans giving information that changed management). We conclude that the increased ease of performance of chest CT in children has not led to a large number of inappropriate requests. In the large majority of cases, diagnostically useful information was provided.

Adolescent↗
PubMed1998

Effect of nickel chloride on mouse T-lymphocyte subsets.

The study was carried out to observe the effect of nickel chloride (NiCl2) on T-lymphocyte subsets, CD4, CD8 and CD4/CD8 ratios in vivo. BALB/C mice were injected i.p. with NiCl2 every other day for 2 w. The NiCl2 doses were 1, 3, 6, 9 or 12 mg/kg. Lymphocytes were obtained from mouse spleen and cultured in the presence of monoclonal antibody FITC conjugated, anti-CD4 or anti-CD8. Samples were determined with a flow cytometer. A suppressive effect on CD4-positive cells was found in the 6 mg/kg group, but this subset was restored to the control level in the 9 and 12 mg/kg groups, suggesting that there was an "immune tolerance" effect. No significant changes were found in CD8-positive cells and CD4/CD8 ratios. The results suggested the NiCl2 had a deleterious effect on mouse T-lymphocytes in short-term in vivo exposure, but the effects may depend on the dose and cell subset.

Animals↗
PubMed1997

DullRazor: a software approach to hair removal from images.

Recently, there has been a growing number of studies applying image processing techniques to analyze melanocytic lesions for atypia and possible malignancy and for total-body mole mapping. However, such lesions can be partially obscured by body hairs. None of these studies has fully addressed the problem of human hairs occluding the imaged lesions. In our previous study we designed an automatic segmentation program to differentiate skin lesions from the normal healthy skin, and learned that the program performed well with most of the images, the exception being those with hairs, especially dark thick hairs, covering part of the lesions. These thick dark hairs confused the program, resulting in unsatisfactory segmentation results. In this paper, we present a method to remove hairs from an image using a pre-processing program we have called DullRazor. This pre-processing step enables the segmentation program to achieve satisfactory results. DullRazor can be downloaded as shareware from http:/(/)www.derm.ubc.ca.

Algorithms↗