Evaluating the Ability to ID (COVID-19) NOW: a Large Real-World Prospective Evaluation of the Abbott ID NOW COVID-19 Assay.

The Abbott ID NOW COVID-19 assay is a rapid point-of-care molecular test for SARS-CoV-2 detection. In theory, it has the potential to decrease turnaround times (TATs) and rapidly facilitate patient flow and triage. Reports for its performance have been mixed, likely due to variations in patient cohorts, preanalytical considerations, and study design. We prospectively evaluated the ID NOW performance against reference reverse transcriptase PCR (RT-PCR) tests, using dual swabs. Patients presented at a large multisite academic hospital with the highest volumes of COVID-19 admissions in Canada. From 1,968 valid swabs, 186 were true positive, 1,760 were true negative, 21 were false negatives, and 1 was false positive. At 10.5% positivity rate, the positive and negative predictive values were 99.5% and 98.8%, respectively. This led to a modest increase in the pretest probability in this cohort of individuals presenting <7 days of symptom onset. The mean times from collection to laboratory receipt and receipt to reporting were 31 and 23 min, respectively. This reduced TAT observed in our study may assist with triage of admitted patients and breaking the chain of transmission through immediate notification of status. We also observed how test performance changed with prevalence, and thus, how the test is used to "rule in" or "rule out" disease must be considered. Although the ID NOW is regarded as a rapid test, it is not high throughput and requires rapid transportation times (<1 h) that may not be plausible in large centers. The utility of this test should be considered with the observed TAT and interpreted in the context of limitations discussed. IMPORTANCE Rapid testing for COVID-19 has been recognized as one potentially important measure in managing the pandemic. However, these rapid tests vary grossly in their performance and their applicability. There have been many studies evaluating the performance of rapid tests for SARS-CoV-2 detection. However, they are frequently not prospective, and patients are not simultaneously swabbed to compare the reference standard RT-PCR. Previous ID NOW study findings are mixed, which may be due to various factors, including patient, epidemiological, and preanalytical considerations. It is critical to consider how the pretest and posttest probabilities and epidemiological factors may affect the performance as the community prevalence of disease fluctuates during this highly dynamic pandemic. We consider how the ID NOW may be utilized in different settings, with considerations of public health and infection control and prevention risk tolerance.

Reducing postsurgical exudate in breast cancer patients by using San Huang decoction to ameliorate inflammatory status: a prospective clinical trial.

Background: Reducing inflammatory factors in wound exudate is a promising treatment approach for healing wounds in postsurgical breast cancer patients. Traditional Chinese Medicine (tcm) treatments have been shown to be beneficial and safe for optimal regulation of oxidative stress during the postoperative period. In the present clinical trial, we evaluated the effectiveness of a promising Chinese herbal formula, San Huang decoction [shd (Radix astragali, Radix et rhizoma rhei, and Rhizoma curcuma longa, 3:1:1; supplemental Table 1)], on wound inflammatory response after mastectomy. Methods: The study randomized 30 patients with breast cancer who fulfilled the inclusion and exclusion criteria to either a treatment (n = 15) or a control group (n = 15). Patients in the treatment group received liquid shd, taken twice daily with or without food. Treatment was given for 1 day before surgery and for 7 days postoperatively. Participants in the control group received a placebo on the same schedule as the treatment group. Outcomes measured in every subject included clinical tcm and wound inflammation symptom scores, daily and total amounts of drainage fluid, and levels of inflammatory factors in the exudate [tumour necrosis factor α (tnf-α), interleukins 6 (il-6), 8 (il-8), and 2R (il-2R), human C-reactive protein (crp)] at 2 hours and on days 1, 3, and 7 postoperatively. Results: The total amount of drainage fluid over 7 days was significantly lower in the treatment group (572.20 ± 93.95 mL) than in the control group (700.40 ± 107.38 mL). The tcm symptom score was also lower in treatment group (day 7: 1.87 ± 0.83 vs. 4.80 ± 3.61, p = 0.049), as was the inflammatory symptom score (day 7: 0.67 ± 0.72 vs. 3.67 ± 2.50, p = 0.001). Levels of tnf-α, il-6, il-8, il-2R, and crp in drainage fluid were significantly lower with shd treatment. Conclusions: Perioperative treatment with shd effectively lessened postoperative exudate and ameliorated inflammatory symptoms in patients who underwent surgery for breast cancer.

Immunologic regulatory effects of human umbilical cord blood-derived mesenchymal stem cells in a murine ovalbumin asthma model.

BACKGROUND: Mesenchymal stem cells (MSCs) have multiple immunomodulatory properties and hold therapeutic potential for inflammatory diseases. However, the therapeutic and immunologic effects of human umbilical cord blood-derived MSCs (huMSCs) remain largely unexamined for asthma. OBJECTIVE: This study was to investigate the immunomodulatory properties of huMSCs in an ovalbumin (OVA)-induced murine asthma model. METHODS: Mice were injected intraperitoneally with OVA and an aluminium hydroxide adjuvant. huMSCs were administered via the tail vein (5×105 cells/100 uL) to female BALB/c mice prior to the initial OVA challenge. The effects of huMSCs were assessed by investigating airway hyperresponsiveness, histological changes, inflammatory cell numbers, serum allergen-specific antibodies, cytokine production in spleen, lung tissue, and bronchoalveolar lavage (BAL) fluid as well as expansion of regulatory T cells. RESULTS: Administration of huMSCs significantly reduced methacholine bronchial hyperresponsiveness and eosinophil counts in BAL cells. Similarly, there was a significant decrease in serum OVA-specific IgE and IgG1 levels along with Th2 cytokine production (IL-4, IL-5, and IL-13) in the lung and spleen tissues, whereas increased percentage of regulatory T cells was observed after treatment with huMSCs. CONCLUSIONS: Our results suggest that huMSC treatment reduces OVA-induced allergic inflammation, which could be mediated by regulatory T cells.

Staphylococcal enterotoxin IgE sensitization in late-onset severe eosinophilic asthma in the elderly.

BACKGROUND: Asthma in the elderly (aged ≥ 65 years old) is a significant concern with high morbidity, but the pathophysiology remains unclear particularly in late-onset asthma. Recent studies suggest staphylococcal enterotoxin IgE (SE-IgE) sensitization to be a risk factor for asthma in general populations; however, the associations have not been examined in late-onset elderly asthma. OBJECTIVE: We aimed to examine the associations of SE-IgE sensitization with late-onset asthma in the elderly, using a database of elderly asthma cohort study. METHODS: A total of 249 elderly patients with asthma and 98 controls were analysed. At baseline, patients were assessed for demographics, atopy, induced sputum profiles and comorbidities including chronic rhinosinusitis (CRS). Serum total IgE and SE-IgE levels were measured. Asthma severity was assessed on the basis of asthma outcomes during a 12-month follow-up period. RESULTS: At baseline, serum SE-IgE concentrations were significantly higher in patients with asthma than in controls [median 0.16 (interquartile range 0.04-0.53) vs. 0.10 (0.01-0.19), P < 0.001]. Elderly asthma patients with high SE-IgE levels had specific characteristics of having more severe asthma, sputum eosinophilia and CRS, compared to those with lower SE-IgE levels. In multivariate logistic regression analyses, the associations between serum SE-IgE concentrations and severe asthma were significant, independently of covariables [SE-IgE-high (≥ 0.35 kU/L) vs. negative (< 0.10 kU/L) group: odds ratio 7.47, 95% confidence interval 1.86-30.03, P = 0.005]. Multiple correspondence analyses also showed that high serum SE-IgE level had close relationships with severe asthma, CRS and sputum eosinophilia together. CONCLUSIONS AND CLINICAL RELEVANCE: This is the first report on the significant associations of SE-IgE sensitization with late-onset asthma in the elderly, particularly severe eosinophilic asthma with CRS comorbidity. Our findings indicate a potential implication of SE in the high morbidity burden of elderly asthma and suggest clues to the pathogenesis of severe late-onset eosinophilic asthma in the elderly.

Buccal administration of human colostrum: impact on the oral microbiota of premature infants.

OBJECTIVE: To determine whether the administration of mother's colostrum into the buccal pouch in the first days of life alters the oral microbiota compared with control infants. STUDY DESIGN: In this pilot study, 12 very low birth weight (VLBW) infants were randomly assigned to receive either colostrum from their mothers directly into the buccal pouch every 2 h for 46 h or standard care. We analyzed the oral microbiota at initiation and 48 and 96 h later using next-generation sequencing. RESULT: The oral microbiota changed markedly over the 96 h period in all babies. Patterns of colonization differed between groups with Planococcaceae, the dominant family at 48 and 96 h in the colostrum group, and Moraxellaceae and Staphylococcaceae, the dominant families at 48 and 96 h, respectively, in the control group. CONCLUSION: Buccal administration of mother's colostrum to VLBW infants influenced the colonization of the oral cavity with differences persisting 48 h after completion of the intervention.

The male-taller norm: Lack of evidence from a developing country.

In general, women prefer men taller than themselves; this is referred to as the male-taller norm. However, since women are shorter than men on average, it is difficult to determine whether the fact that married women are on average shorter than their husbands results from the norm or is a simple artifact generated by the shorter stature of women. This study addresses the question by comparing the rate of adherence to the male-taller norm between actual mating and hypothetical random mating. A total of 7954 actually married couples are drawn from the last follow-up of the Indonesian Family Life Survey, a nationally representative survey. Their heights were measured by trained nurses. About 10,000 individuals are randomly sampled from the actual couples and randomly matched. An alternative random mating of about 100,000 couples is also performed, taking into account an age difference of 5 years within a couple. The rate of adherence to the male-taller norm is 93.4% for actual couples and 88.8% for random couples. The difference between the two figures is statistically significant, but it is emphasized that it is very small. The alternative random mating produces a rate of 91.4%. The male-taller norm exists in Indonesia, but only in a statistical sense. The small difference suggests that the norm is mostly explained by the fact that women are shorter than men on average.

Proton pump inhibitors as a possible cause of vitiligo: an in vivo and in vitro study.

BACKGROUND: Vitiligo is an acquired depigmentation disorder of melanocytes. Recently, some clinical reports have suggested that proton pump inhibitors (PPIs) may worsen vitiligo, but their effects on melanocytes have yet to be elucidated. OBJECTIVE: We investigated the effect of PPIs on melanogenesis in vivo and in vitro. METHODS: We examined the effect of PPIs on melanogenesis in B16 murine melanoma cells by measuring melanin content and tyrosinase (TYR) activity. TYR and tyrosinase-related protein-1 (TRP-1) were monitored by western blotting. Finally, a PPI was applied to zebrafish embryos to investigate its in vivo effect on pigmentation. RESULTS: In agreement with our clinical experience of worsened vitiligo after PPI treatment, PPIs decreased both melanin content and TYR activity. Western blotting showed that PPIs decreased TYR and TRP-1 protein levels. In the zebrafish test, PPIs inhibited body pigmentation in a dose-dependent manner. CONCLUSION: These results suggest that the functional inhibition of melanization by PPIs may induce or aggravate vitiligo lesions in genetically predisposed patients.

γ-Glutamyl hydrolase modulation and folate influence chemosensitivity of cancer cells to 5-fluorouracil and methotrexate.

BACKGROUND: γ-Glutamyl hydrolase (GGH) regulates intracellular folate and antifolates for optimal nucleotide biosynthesis and antifolate-induced cytotoxicity, respectively. The modulation of GGH may therefore affect chemosensitivity of cancer cells, and exogenous folate levels may further modify this effect. METHODS: We generated a novel model of GGH modulation in human HCT116 and MDA-MB-435 cancer cells and investigated the effect of GGH modulation on chemosensitivity to 5-fluorouracil (5FU) and methotrexate (MTX) at different folate concentrations in vitro and in vivo. RESULTS: Overexpression of GGH significantly decreased chemosensitivity of MDA-MB-435 cells to 5FU and MTX at all folate concentrations as expected. In contrast, in HCT116 cells this predicted effect was observed only at very high folate concentration, and as the folate concentration decreased this effect became null or paradoxically increased. This in vitro observation was confirmed in vivo. Inhibition of GGH significantly increased chemosensitivity of both cancer cells to 5FU at all folate concentrations. Unexpectedly, GGH inhibition significantly decreased chemosensitivity of both cancer cells to MTX at all folate concentrations. In both GGH modulation systems and cell lines, the magnitude of chemosensitivity effect incrementally increased as folate concentration increased. CONCLUSION: Modulation of GGH affects chemosensitivity of cancer cells to 5FU and MTX, and exogenous folate levels can further modify the effects.

A family of secreted pathogenesis-related proteins in Candida albicans.

Analysing culture supernatants of yeast and hyphal cells of Candida albicans, we found two close homologues of pathogenesis-related (PR-) 1 proteins, Rbe1p and Rbt4p, in the secretome. Due to sequence homology, three additional, yet not characterized open reading frames, ORF19.6200, ORF19.2787 and ORF19.2336, together with RBE1 and RBT4 were assigned to a novel family of CaPRY proteins. In a Δrbe1/Δrbt4 deletion strain, genome-wide transcriptional analysis revealed differential transcription of only a limited set of genes implicated in virulence and oxidative stress response. Single deletion of RBE1 or RBT4 in a clinical C. albicans isolate resulted in a moderate but significant attenuation in virulence in a mouse model for disseminated candidiasis. However, a synergistic effect was observed in a Δrbe1/Δrbt4 double deletion strain, where virulence was strongly affected. Remarkably, transcription of RBT4 and RBE1 was each upregulated in blastospores of Δrbe1 or hyphae of Δrbt4 deletion strains respectively, indicating functional complementation thereby compensating a potential virulence defect in the single deletion strains. Furthermore, the double deletion strain showed increased sensitivity to attack by polymorphonuclear leucocytes. Therefore, the crucial contribution of both C. albicans pathogenesis-related proteins to virulence might be vested in protection against phagocyte attack.

Hair greying is associated with active hair growth.

BACKGROUND: Hair greying is an obvious sign of ageing in humans. White (nonpigmented) hair is thicker than black (pigmented) hair. The growth rate of white hair is also significantly higher than that of black hair. However, the mechanism underlying this is largely unknown. OBJECTIVES: To examine the association between hair greying and hair growth patterns by evaluating expression of the genes or proteins related to hair growth in white and black hairs. METHODS: Morphological characteristics were observed in eyebrow and scalp hairs. The differential expression of genes was analysed in black and white hairs from human scalp by a microarray analysis. Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry for genes and proteins related to hair growth were performed in black and white hairs. RESULTS: Keratin and keratin-associated protein (KRTAP) genes in white hair were upregulated at least two-fold in comparison with black hair in a microarray analysis. Upregulation of selected keratin genes and KRTAP4 isoform genes in white hair was validated by RT-PCR. Immunoreactivity for KRT6, KRT14/16 and KRT25 was increased in the hair follicle of white hair compared with black hair. Gene expression of fibroblast growth factor 5 (FGF5) was downregulated in white hair compared with black hair. However, gene expression of FGF7 was upregulated in white hair compared with black hair. CONCLUSIONS: Expression of genes and proteins associated with active hair growth is upregulated in white (nonpigmented) hair compared with black (pigmented) hair. These results suggest that hair greying is associated with active hair growth.

Translationally controlled tumor protein induces human breast epithelial cell transformation through the activation of Src.

Translationally controlled tumor protein (TCTP) is implicated in cell growth and malignant transformation. TCTP has been found to interact directly with the third cytoplasmic domain of the α subunit of Na,K-ATPase, but whether this interaction has a role in tumorigenesis is unclear. In this study, we examined TCTP-induced tumor progression signaling networks in human breast epithelial cells, using adenoviral infection. We found that TCTP (a) induces Src release from Na,K-ATPase α subunit and Src activation; (b) phosphorylates tyrosine residues 845, 992, 1086, 1148 and 1173 on anti-epidermal growth factor receptor (EGFR); (c) activates PI3K (phosphatidylinositol 3-kinase )-AKT, Ras-Raf-MEK-ERK1/2, Rac-PAK1/2, MKK3/6-p38 and phospholipase C (PLC)-γ pathways; (d) enhances NADPH oxidase-dependent reactive oxygen species (ROS) generation; (e) stimulates cytoskeletal remodeling and cell motility and (f) upregulates matrix metalloproteinase (MMP) 3 and 13. These findings suggest that TCTP induces tumorigenesis through distinct multicellular signaling pathways involving Src-dependent EGFR transactivation, ROS generation and MMP expression.

Callus formation is associated with hyperproliferation and incomplete differentiation of keratinocytes, and increased expression of adhesion molecules.

BACKGROUND: A callus is a local thickening of skin, characterized by accelerated keratinization and a reduced rate of desquamation. However, the mechanism of callus formation is not fully understood. OBJECTIVES: To evaluate the expression patterns, in callused skin, of genes that are implicated in keratinization and adhesion/desquamation. METHODS: Samples of skin from the dorsum of the foot (DF), centre of the plantar arch (CP) and anterior aspect of the heel (AH) were obtained from fresh cadavers, and protein and gene expression were determined by immunohistochemistry and reverse transcription-polymerase chain reaction, respectively. RESULTS: The stratum corneum in the DF showed a splitting phenotype by conventional haematoxylin and eosin staining, while the stratum corneum was normal in the AH. Cells of the stratum corneum in the AH were nonsquamous. Expression of cornification-related molecules including involucrin, filaggrin, caspase 14 and calcium-sensing receptor was higher in the AH. Similarly, expression of adhesive proteins such as corneodesmosin, desmoglein 1 and desmocollin 1 was increased in the AH. However, protease-activated receptor 2 expression was reduced in the stratum granulosum in the AH. The number of proliferating cells in the stratum basale was significantly increased in the AH, compared with the DF and CP. CONCLUSIONS: Our data suggest that calluses form as a result of hyperproliferation and incomplete differentiation of epidermal keratinocytes, and increased expression of adhesion molecules.

Novel anti-apoptotic mechanism of A20 through targeting ASK1 to suppress TNF-induced JNK activation.

The zinc-finger protein A20 has crucial physiological functions as a dual inhibitor of nuclear factor-κB (NF-κB) activation and apoptosis in tumor necrosis factor (TNF) receptor 1 signaling pathway. Although the molecular basis for the anti-NF-κB function of A20 has been well elucidated, the anti-apoptotic function of A20 is largely unknown. Here, we report a novel mechanism underlying the anti-apoptotic function of A20: A20 blocks TNF-induced apoptosis through suppression of c-jun N-terminal kinase (JNK) by targeting apoptosis signal-regulating kinase1 (ASK1). First, the ectopic expression of A20 drastically inhibits TNF-induced JNK activation and apoptosis in multiple cell types including those deficient of NF-κB activation. Unexpectedly, the blunting effect of A20 on TNF-induced JNK activation is not mediated by affecting the TNFR1 signaling complex formation. Instead, A20 interacts with ASK1, an important MAPKK kinase in the JNK signaling cascade. More importantly, overexpression of wild-type A20, but not of mutant A20 (ZnF4; C624A, C627A), promotes degradation of the ASK1 through the ubiquitin-proteasome system. Taken together, the results from this study reveal a novel anti-apoptotic mechanism of A20 in TNF signaling pathway: A20 binds to ASK1 and mediates ASK1 degradation, leading to suppression of JNK activation and eventually blockage of apoptosis.

Determination of the electron escape depth for NEXAFS spectroscopy.

A novel method was developed to determine carbon atom density as a function of depth by analyzing the postedge signal in near-edge X-ray absorption fine structure (NEXAFS) spectra. We show that the common assumption in the analysis of NEXAFS data from polymer films, namely, that the carbon atom density is constant as a function of depth, is not valid. This analysis method is then used to calculate the electron escape depth (EED) for NEXAFS in a model bilayer system that contains a perfluorinated polyether (PFPE) on top of a highly oriented pyrolitic graphite (HOPG) sample. Because the carbon atom densitites of both layers are known, in addition to the PFPE surface layer thickness, the EED is determined to be 1.95 nm. This EED is then used to measure the thickness of the perfluorinated surface layer of poly(4-(1H,1H,2H,2H-perfluorodecyl)oxymethylstyrene) (PFPS).

Experimental and computational studies of strain-conduction velocity relationships in cardiac tissue.

Velocity of electrical conduction in cardiac tissue is a function of mechanical strain. Although strain-modulated velocity is a well established finding in experimental cardiology, its underlying mechanisms are not well understood. In this work, we summarized potential factors contributing to strain-velocity relationships and reviewed related experimental and computational studies. We presented results from our experimental studies on rabbit papillary muscle, which supported a biphasic relationship of strain and velocity under uni-axial straining conditions. In the low strain range, the strain-velocity relationship was positive. Conduction velocity peaked with 0.59 m/s at 100% strain corresponding to maximal force development. In the high strain range, the relationship was negative. Conduction was reversibly blocked at 118+/-1.8% strain. Reversible block occurred also in the presence of streptomycin. Furthermore, our studies revealed a moderate hysteresis of conduction velocity, which was reduced by streptomycin. We reconstructed several features of the strain-velocity relationship in a computational study with a myocyte strand. The modeling included strain-modulation of intracellular conductivity and stretch-activated cation non-selective ion channels. The computational study supported our hypotheses, that the positive strain-velocity relationship at low strain is caused by strain-modulation of intracellular conductivity and the negative relationship at high strain results from activity of stretch-activated channels. Conduction block was not reconstructed in our computational studies. We concluded this work by sketching a hypothesis for strain-modulation of conduction and conduction block in papillary muscle. We suggest that this hypothesis can also explain uni-axially measured strain-conduction velocity relationships in other types of cardiac tissue, but apparently necessitates adjustments to reconstruct pressure or volume related changes of velocity in atria and ventricles.

Identification and characterization of Cor33p, a novel protein implicated in tolerance towards oxidative stress in Candida albicans.

We applied two-dimensional gel electrophoresis to identify downstream effectors of CPH1 and EFG1 under hypha-inducing conditions in Candida albicans. Among the proteins that were expressed in wild-type cells but were strongly downregulated in a cph1Delta/efg1Delta double mutant in alpha-minimal essential medium at 37 degrees C, we could identify not-yet-characterized proteins, including Cor33-1p and Cor33-2p. The two proteins are almost identical (97% identity) and represent products of allelic isoforms of the same gene. Cor33p is highly similar to Cip1p from Candida sp. but lacks any significant homology to proteins from Saccharomyces cerevisiae. Strikingly, both proteins share homology with phenylcoumaran benzylic ether reductases and isoflavone reductases from plants. For other hypha-inducing media, like yeast-peptone-dextrose (YPD) plus serum at 37 degrees C, we could not detect any transcription for COR33 in wild-type cells, indicating that Cor33p is not hypha specific. In contrast, we found a strong induction for COR33 when cells were treated with 5 mM hydrogen peroxide. However, under oxidative conditions, transcription of COR33 was not dependent on EFG1, indicating that other regulatory factors are involved. In fact, upregulation depends on CAP1 at least, as transcript levels were clearly reduced in a Deltacap1 mutant strain under oxidative conditions. Unlike in wild-type cells, transcription of COR33 in a tsa1Delta mutant can be induced by treatment with 0.1 mM hydrogen peroxide. This suggests a functional link between COR33 and thiol-specific antioxidant-like proteins that are important in the oxidative-stress response in yeasts. Concordantly, cor33Delta deletion mutants show retarded growth on YPD plates supplemented with hydrogen peroxide, indicating that COR33 in general is implicated in conferring tolerance toward oxidative stress on Candida albicans.

Effects of folylpolyglutamate synthetase modulation on chemosensitivity of colon cancer cells to 5-fluorouracil and methotrexate.

BACKGROUND: Folylpoly-gamma-glutamate synthetase (FPGS) converts intracellular folates and antifolates (for example, methotrexate (MTX)) to polyglutamates. Polyglutamylated folates and antifolates are retained in cells longer and are better substrates than their monoglutamate counterparts for enzymes involved in one carbon transfer. Polyglutamylation of intracellular 5,10-methylenetetrahydrofolate may also enhance the cytotoxicity of 5-fluorouracil (5-FU) by allowing more efficient formation and stabilisation of the inhibitory ternary complex involving thymidylate synthase and a 5-FU metabolite. AIM: We investigated the effects of FPGS modulation on the chemosensitivity of colon cancer cells to 5-FU and MTX. METHODS: Human HCT116 colon cancer cells were stably transfected with the sense or antisense FPGS cDNA or blank (control). FPGS protein expression and enzyme activity, growth rate, intracellular folate content and composition, and in vitro chemosensitivity to 5-FU and MTX were determined. RESULTS: Compared with cells expressing endogenous FPGS, those overexpressing FPGS had significantly faster growth rates and higher concentrations of total folate and long chain folate polyglutamates while antisense FPGS inhibition produced opposite results. FPGS overexpression significantly enhanced, whereas FPGS inhibition decreased, chemosensitivity to 5-FU. No significant difference in chemosensitivity to MTX was observed. CONCLUSIONS: These data provide functional evidence that FPGS overexpression and inhibition modulate chemosensitivity of colon cancer cells to 5-FU by altering intracellular folate polyglutamylation, providing proof of principle. Thus FPGS status may be an important predictor of chemosensitivity of colon cancer cells to 5-FU based chemotherapy, and FPGS gene transfer may increase the sensitivity of colon cancer cells to 5-FU-based chemotherapy.

Identification of cell surface determinants in Candida albicans reveals Tsa1p, a protein differentially localized in the cell.

To identify cell surface proteins of Candida albicans, the predominant fungal pathogen in humans, we have established an approach using a membrane impermeable biotin derivative in combination with affinity purification. We were able to identify 29 different proteins under two distinct conditions. Among mannoproteins, heat shock proteins and glycolytic enzymes we found thiol-specific antioxidant-like protein 1 (Tsa1p) to be differentially localized depending on the conditions applied. Only in hyphally grown cells Tsa1p was localized to the cell surface whereas in blastospores no surface but mainly nuclear localization was found. This indicates that cell surface expression of at least some proteins is mediated by differential translocation.