P-046 Effect of different sperm chromatin dispersion type on IVF/ICSI outcome and offspring profile

Study question

Whether the percentage of different sperm chromatin dispersion type are associated with the IVF/ICSI outcome and offspring profile?

Summary answer

Percentage of different sperm chromatin dispersion type are significantly associated with the embryo cleavage rate, embryo quality, live birth rate and offspring gender.

What is known already

The sperm DNA fragmentation index (DFI) is increasingly recognized as a key sperm functional parameter for assessing male fertility. Sperm chromatin dispersion (SCD) test is widely used in clinical andrology lab to measure DFI, and according to the size of sperm halo it divides sperm into three categories: big halo sperm, middle halo sperm, small or no halo sperm. Previous study reported that big halo sperm are significantly associated with embryo quality and pregnancy rate. The average halo size of Y-chromosome bearing sperm are significantly smaller than X - chromosome bearing sperm.

Study design, size, duration

This is a multi-center retrospective study recruited 200 couples underwent IVF/ICSI treatment in Nanfang Hospital and Guangdong Women's and Children's Hospital from May 2018 to May 2019.

Participants/materials, setting, methods

Patients meet the followed inclusion criteria were recruited: (1) The male partners received sperm chromatin dispersion test; (2) The female partners have normal ovarian reserve (female age < 35 years old, FSH ≤10 IU/L and AFC ≥ 5); (3) Couples received fresh single embryo transfer. The association between sperm chromatin dispersion type and IVF/ICSI outcome and the offspring profile were retrospectively analyzed.

Main results and the role of chance

Regression analysis showed that the embryo cleavage rate is positively associated with the percentage of sperm with big halo (Adjusted ?????(95% CI) 0.09 (0.01, 0.17), P<0.05), but negatively associated with the percentage of sperm with middle halo (Adjusted ????? (95% CI)- 0.22 (-0.35, -0.09), P<0.001). The good embryo rate is negatively associated with the percentage of sperm with middle halo (Adjusted ????? (95% CI) -0.60 (-1.04, -0.16), P<0.05). Live birth is significantly associated with the percentage of sperm with small halo (Adjusted OR (95% CI) 0.89 (0.80, 1.00), P<0.05). Offspring gender is significantly associated with the percentage of sperm with big halo (Adjusted OR (95% CI) 0.95 (0.91, 0.99), P<0.05) and the percentage of sperm with middle halo (Adjusted OR (95% CI) 1.09 (1.02, 1.17), P<0.05). The area under the receiver operator characteristic (ROC) curve (AUC) of the big halo sperm percentage to predict male offspring is 0.68 (95%CI (0.54, 0.81), P < 0.05). The AUC of middle halo sperm percentage to predict female offspring is 0.66 (95%CI (0.52, 0.80), P < 0.05).

Limitations, reasons for caution

This is a retrospective study which may have the bias caused by the nature of this type of study. The sample size is relatively small.

Wider implications of the findings

The percentage of big halo sperm are significantly associated with embryo cleavage rate and male offspring. The percentage of middle halo sperm are significantly associated with embryo cleavage rate, lower good embryo rate and female offspring. The percentage of small halo sperm is significantly associated with live birth.

Trial registration number

82101683

A diagnostic test that uses isothermal amplification and lateral flow detection sdaA can detect tuberculosis in 60 min

AIMS

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is now the leading cause of death from infectious disease, thus rapid diagnostic and screening techniques for TB are urgently needed.

METHODS AND RESULTS

Here, a detection of MTB using multiple cross displacement amplification coupling with nanoparticles-based lateral flow device (MCDA-LFD) was developed and validated, targeting the specific sdaA gene. The whole detection procedure, including rapid genomic DNA extraction (15 min), amplification (30 min) and result reporting (2 min), was completed within 50 min. No cross-reaction with non-mycobacteria and non-tuberculous mycobacteria (NTM) strains was observed. The sensitivity of sdaA-MCDA-LFD, Xpert MTB/RIF assay and culture results was 81·6, 48·3 and 37·9%, respectively, in TB patients. Among positive culture samples, the sensitivity of sdaA-MCDA-LFD and Xpert MTB/RIF assay was 93·9% (31/33) and 81·8% (27/33), respectively. Among culture-negative samples, the sensitivity of sdaA-MCDA-LFD and Xpert MTB/RIF assay was 74·1% (40/54) and 27·8% (15/54), respectively. The specificity of sdaA-MCDA-LFD and Xpert MTB/RIF was 95·4% (62/65) and 100% (65/65) in clinical samples from non-TB patients.

CONCLUSION

The sdaA-MCDA-LFD assay was a rapid, simple, specific and sensitive TB diagnostic test.

SIGNIFICANCE AND IMPACT OF THE STUDY

The sdaA-MCDA-LFD assay holds promise for application as a useful point-of-care test to detect MTB, and will play an important role in controlling and preventing TB.

0595 Obstructive Sleep Apnea Characteristics in Younger Versus Older Women

Introduction

There are few large studies of obstructive sleep apnea (OSA) comparing the clinical and polysomnographic characteristics between men and women, and between younger and older women.

Methods

The current study involves retrospective analyses of data from the Apnea Positive Pressure Long-term Efficacy Study (APPLES), a prospective multicenter randomized controlled trial in persons with OSA. The mean age of the 1105 participants was 51.6 ± 12 years (range 18-83 years). The participants included 723 men (65.4%) and 382 women (34.6%). Of all women, 25% were <=45 years of age (likely pre-menopausal) and 50% were above >=53 years of age (likely post-menopausal). We used these 2 groups to define younger women and older women, respectively.

Results

The overall mean body mass index (BMI) and apnea hypopnea index (AHI) were 32.2 ± 7.1 Kg/m2 and 40.1 ± 25.2 (range 6-156/hour), respectively. Women had a higher BMI and Epworth Sleepiness Scale (ESS) than men but a lower AHI and lower arousal index (AI). The Hamilton Rating Scale for Depression (HAMD) score was also significantly higher in women. Younger men and women had no other PSG differences including total sleep time (TST), Sleep Efficiency (SE), Sleep Onset Latency (SOL). Older women had lower AHI, higher TST and higher SE than older men. Morningness-Eveningness Questionnaire (MEQ) scores were lower in women than in men in all age groups (suggestive of eveningness). Compared to the older women, younger women had higher BMI, HAMD score and ESS, but lower MEQ score. On PSG, younger women had higher TST and SE but similar SOL, AHI and AI.

Conclusion

In this cohort with OSA, the prevalence of sleepiness and depression is higher in women than in men despite a lower AHI and lower AI. Sleepiness and depression are more common in younger compared to older women with OSA despite similar AHI and AI and a higher SE. Women with OSA demonstrate more ‘eveningness’ compared to men with OSA, as do younger women compared to older women.

Support

Contract 5UO1-HL-068060 from the National Heart, Lung and Blood Institute

1047 Social Rhythm Instability Is Associated With Abdominal Adiposity After Involuntary Job Loss

Introduction

Involuntary job loss is an acute stressor that disrupts daily time structure and activity and exacerbates economic hardship and psychological distress. Studies show that unemployment is associated with negative obesity-related health outcomes, such as metabolic syndrome. However, very little is known about daily routine, depression, and obesity in individuals who have recently experienced involuntary job loss. We hypothesized that individuals with less consistent daily routines, or unstable social rhythms, after job-loss would have more abdominal adiposity than individuals with more consistent social rhythms. We also hypothesized that this relationship would vary as a function of depressive symptoms.

Methods

Cross-sectional baseline data (n = 186) from the ongoing ADAPT study (Assessing Daily Activity Patterns through occupational Transitions) were analyzed using linear regression techniques. Participants were predominantly female (62%) with a mean age of 41.12 years (SD = 10.16 years); 31% were Hispanic or Latino. Over two weeks, participants completed the daily Social Rhythm Metric-17 (SRM), Beck Depression Inventory II (BDI), and waist circumference (adiposity) measurements (cm).

Results

A significant BDI x SRM interaction was detected in the prediction of waist circumference, B = .36, SE = .18, <i> p </i> < .05, 95% CI [.002, .709], R2 = .07). The SRM was inversely associated with waist circumference, B = -5.57, SE = 2.25, <i> p </i> < .05, 95% CI [-9.98, -1.13], only at lower levels of BDI (-1 SD below the mean). Results from the Johnson-Neyman technique identified that the conditional effect of SRM on waist circumference was statistically significant at a BDI raw score of 8.33 (0-13 points is minimal depression) with ~45% of cases within this region.

Conclusion

A less consistent daily routine was associated with a larger waist circumference among individuals with minimal depressive symptoms. These findings are the first to demonstrate a relationship between social rhythm stability and abdominal adiposity in adults at high risk for central obesity. Results highlight the moderating role of depression in obesity prevention. Future prospective analysis is necessary to examine causal pathways.

Support

#1R01HL117995-01A1

[Effects and mechanism of lncRNA serving as ceRNA in non-obstructive azoospermia]

Objective: To investigate the mechanisms of lncRNA on the occurrence and development of NOA by constructing ceRNA regulation network of lncRNA, miRNA and mRNA. Methods: Samples of adult human testis were obtained from NOA patients and OA patients with normal spermatogenesis (controls), recruited from the Reproductive Medicine Center of Nanfang Hospital from June 2017 to June 2018. Differentially expressed lncRNAs and mRNAs in testicular tissues from patients with NOA were identified by microarray analysis in previous association study. In this study, differentially expressed lncRNAs and mRNA were used to construct the ceRNA regulatory network in NOA and clarify the interaction relationship among lncRNA, miRNA and mRNA. GeneMANIA database was used to construct Protein-Protein Interaction (PPI) of the mRNAs in ceRNA regulatory network. WebGestalt toolkit was employed to perform gene function and pathway enrichment analyses of those coding genes. Finally, qRT-PCR and dual luciferase reporter system were employed for further experimental validation. Results: The ceRNA regulatory network of lncRNA, miRNA and mRNA consists of 21 nodes and 26 edges, of which 4 lncRNAs, 13 miRNAs and 4 mRNAs. 19 proteins were found to interact with the mRNA coding proteins in ceRNA regulatory network by PPI analysis. Gene oncology and KEGG pathway enrichment analyses indicate these coding genes were significantly enriched in pentose metabolic process and pentose phosphate pathway. Furthermore, lncRNA ANXA2P3 was found binding with miR-613 and miR-206 to inhibit mRNA TKT expression. Conclusion: lncRNAs exert an important role in the occurrence and development of NOA via ceRNA regulatory network, which could be used as new biomarkers for NOA treatment.

Targeting C3a/C5a receptors inhibits human mesangial cell proliferation and alleviates immunoglobulin A nephropathy in mice

Complement activation has a deep pathogenic influence in immunoglobulin (Ig)A nephropathy (IgAN). C3a and C5a, small cleavage fragments generated by complement activation, are key mediators of inflammation. The fragments exert broad proinflammatory effects by binding to specific receptors (C3aR and C5aR, respectively). However, no studies thus far have investigated the effects of C3a, C5a and their receptors on IgAN. We observed that C3aR and C5aR antagonists repressed IgA-induced cell proliferation and interleukin (IL)-6 and monocyte chemotactic protein 1 (MCP-1) production in cultured human mesangial cells (HMCs). Furthermore, an IgAN mouse model induced by Sendai virus infection was employed to investigate the effects of C3aR and C5aR on IgAN in vivo for the first time. Wild-type (WT) and several knock-out mouse strains (C3aR^-/- or C5aR^-/- ) were immunized intranasally with increasing doses of inactivated virus for 14 weeks and were subjected to two intravenous viral challenges during the time-period indicated. In the Sendai virus-induced IgAN model, C3aR/C5aR-deficient mice had significantly reduced proteinuria, lower renal IgA and C3 deposition, less histological damage and reduced mesangial proliferation compared with WT mice. Both C3aR deficiency and C5aR deficiency, especially C3aR deficiency, inhibited renal tumour necrosis factor (TNF)-α, transforming growth factor (TGF)-β, IL-1β, IL-6 and MCP-1 expression significantly. However, C3aR/C5aR-deficient and WT mice with IgAN did not differ with respect to their blood urea nitrogen (BUN) and serum creatinine levels. Our findings provide further support for the idea that C3aR and C5aR are crucially important in IgAN, and suggest that pharmaceutically targeting C3aR/C5aR may hold promise for the treatment of IgAN.

The metabolic responses of HepG2 cells to the exposure of mycotoxin deoxynivalenol

As the number of reported deoxynivalenol (DON) contamination incidents increased steadily over the past decades, there has been a widespread interest in understanding the cellular mechanisms of the toxicological effects of DON using in vitro systems and omics technologies. The present investigation was conducted to understand the metabolomic changes in human hepatocellular carcinoma cells (HepG2) exposed to 10 μM DON for short term (4 h) and long term (12 h) periods, using a non-targeted metabolomics approach. Our results revealed a remarkable metabolic shift from short term to long term exposure to DON in HepG2 cells. Our metabolomics data also confirmed the role of DON induced oxidative stress in DON toxicity. Coupled with pattern recognition and pathway analysis, effects of DON on redox homeostasis, energy balance, lipid metabolism, and potential toxicological mechanisms were discussed, which would facilitate further studies on the risk assessment of the dietary mycotoxin DON.

Regulatory T and B lymphocytes in a spontaneous autoimmune polyneuropathy

B7-2(-/-) non-obese diabetic (NOD) mice develop a spontaneous autoimmune polyneuropathy (SAP) that mimics the progressive form of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). In this study, we focused on the role of regulatory T cells (Tregs ) and regulatory B cells (Bregs ) in SAP. We found that deletion of B7-2 in female NOD mice led to a lower frequency and number of Tregs and Bregs in spleens and lymph nodes. Tregs but not Bregs suppressed antigen-stimulated splenocyte proliferation, whereas Bregs inhibited the T helper type 1 (Th1) cytokine response. Both Tregs and Bregs induced an increase in CD4(+) interleukin (IL)-10(+) cells, although less effectively in the absence of B7-2. Adoptive transfer studies revealed that Tregs , but not Bregs , suppressed SAP, while Bregs attenuated disease severity when given prior to symptom onset. B cell deficiency in B cell-deficient (muMT)/B7-2(-/-) NOD mice prevented the development of SAP, which would indicate that the pathogenic role of B cells predominates over its regulatory role in this model. We conclude that Bregs and Tregs control the immunopathogenesis and progression of SAP in a non-redundant fashion, and that therapies aimed at expansion of Bregs and Tregs may be an effective approach in autoimmune neuropathies.

The use of smartphones on General Internal Medicine wards: a mixed methods study

OBJECTIVE

To describe the uses of institutional and personal smartphones on General Internal Medicine wards and highlight potential consequences from their use.

METHODS

A mixed methods study consisting of both quantitative and qualitative research methods was conducted in General Internal Medicine wards across four academic teaching hospitals in Toronto, Ontario. Participants included medical students, residents, attending physicians and allied health professionals. Data collection consisted of work shadowing observations, semi-structured interviews and surveys.

RESULTS

Personal smartphones were used for both clinical communication and non-work-related activities. Clinicians used their personal devices to communicate with their medical teams and with other medical specialties and healthcare professionals. Participants understood the risks associated with communicating confidential health information via their personal smartphones, but appear to favor efficiency over privacy issues. From survey responses, 9 of 23 residents (39%) reported using their personal cell phones to email or text patient information that may have contained patient identifiers. Although some residents were observed using their personal smartphones for non-work-related activities, personal use was infrequent and most residents did not engage in this activity.

CONCLUSION

Clinicians are using personal smartphones for work-related purposes on the wards. With the increasing popularity of smartphone devices, it is anticipated that an increasing number of clinicians will use their personal smartphones for clinical work. This trend poses risks to the secure transfer of confidential personal health information and may lead to increased distractions for clinicians.

Systematic review: the relationship between interstitial lung diseases and gastro-oesophageal reflux disease

BACKGROUND  A potential relationship has been suggested between gastro-oesophageal reflux disease (GERD) and interstitial lung diseases (ILDs). AIM  To evaluate whether there is a causal relationship between GERD and different ILDs. METHODS  We conducted a systematic search of literature published between 1980 and 2010. After a review by two independent authors, each study was assigned an evidence-based rating according to a standard scoring system. RESULTS  We identified 319 publications and 22 of them met the entry criteria. Of those, the relationship between GERD and idiopathic pulmonary fibrosis (IPF) was investigated in 14 articles, pulmonary involvement in systemic sclerosis (SSc) in six articles and pulmonary involvement in mixed connective tissue disease (MCTD) in two articles. We found the prevalence of GERD and/or oesophageal dysmotility to be higher in patients with different types of ILD as compared with those without ILD [Evidence B]. Among patients with IPF, 67-76% demonstrated abnormal oesophageal acid exposure off PPI treatment. No relationship was demonstrated between severity of GERD and severity of IPF [Evidence B]. Data are scant on outcomes of antireflux treatment in patients with IPF. There is a correlation between the severity of ILD and the degree of oesophageal motor impairment in patients with SSc and MCTD [Evidence B]. CONCLUSIONS  Based on the currently available data, a causal relationship between GERD and idiopathic pulmonary fibrosis cannot be established. There is scant evidence about antireflux therapy in idiopathic pulmonary fibrosis patients. There may be an association between lung and oesophageal involvement in systemic sclerosis and mixed connective tissue disease, but a causal relationship cannot be established.

Implementation and evaluation of an alpha-numeric paging system on a resident inpatient teaching service

BACKGROUND

Numeric pagers are commonly used communication devices in healthcare, but cannot convey important information such as the reason for or urgency of the page. Alphanumeric pagers can display both numbers and text, and may address some of these communication problems.

OBJECTIVE

Our primary aim was to implement an alphanumeric paging system.

DESIGN

Continuous quality improvement study using rapid-cycle change methods.

SETTING

General Internal Medicine (GIM) inpatient wards at 1 tertiary care academic teaching hospital.

PARTICIPANTS

All residents, attending physicians, nurses, and allied health staff working on the general medicine (GM) wards.

MEASUREMENTS

We measured: (1) the proportion of pages sent as text pages, (2) the source of the pages, (3) the content of the text pages, (4) the pages that disrupted scheduled education activities, and (5) satisfaction with the alphanumeric paging system.

RESULTS

After implementation, 52% of pages sent from physicians or the GM wards were sent as text pages (P < 0.001). 93% of pages between physicians were text pages, compared to 27% of pages from the GM wards to physicians (P < 0.001). The most common reason for text paging among physicians was to arrange work or teaching rounds (33%). The most common reason for text paging from the GM wards was to request a patient assessment or for notification of a patient's clinical status (25%). There was a 29% reduction in disruptive pages sent during scheduled educational rounds (P < 0.001).

CONCLUSIONS

We successfully implemented an alphanumeric paging system that reduced disruptive pages on a GM inpatient service.

The methyltransferase domain of the 1a protein of cowpea chlorotic mottle virus controls local and systemic accumulation in cowpea

The type strain of cowpea chlorotic mottle virus (CCMV-T) induces a local and systemic infection in California Blackeye cowpea (Vigna unguiculata (L.) Walp. subs. unguiculata cv. California Blackeye), but accumulates to low levels in inoculated leaves and fails to accumulate systemically in the cowpea plant introduction (PI) 186465. CCMV-R, a mutant strain derived from CCMV-T, accumulates to higher levels than CCMV-T in inoculated leaves and systemically infects PI 186465 plants. The phenotypic determinant of CCMV-R was previously mapped to viral RNA1, but the location of the determinant within RNA1 was not identified. Pseudorecombinants generated from genomic cDNA clones of CCMV-T and CCMV-R indicated that the phenotypic differences on PI 186465 were independent of replication. Through the use of chimeric RNA1 cDNA clones containing portions of CCMV-T and CCMV-R and site-directed mutagenesis, two nucleotides, 299 (amino acid residue 77) and 951 (amino acid residue 294), were identified as being independently critical for the local and systemic accumulation patterns of CCMV-R in PI 186465 plants. A second independently derived CCMV-R-like mutant, identified nucleotide 216 (amino acid residue 49) as being critical for induction of the CCMV-R infection phenotype. Amino acid residues 49, 77, and 294 are within the methytransferase domain of the CCMV 1a protein, suggesting that the methytransferase domain has a role in cell-to-cell and systemic accumulation of the virus that is independent of replication.

Heme oxygenase-1 protects against radiocontrast-induced acute kidney injury by regulating anti-apoptotic proteins

Radiocontrast agents are thought to induce acute kidney injury in part through increased production of reactive oxygen species and increased cellular apoptosis. In this study we determined whether heme oxygenase-1 could prevent or reduce radiocontrast-induced acute kidney injury and, if so, what were the mechanisms by which this can occur. Sodium iothalamate was administered to uninephrectomized, salt-depleted male Sabra rats to initiate acute kidney injury. Heme oxygenase-1 was induced with cobalt protoporphyrin or inhibited with stannous mesoporphyrin. Inhibition of heme oxygenase exacerbated kidney injury as measured by an increase in plasma creatinine and in superoxide production. Heme oxygenase-1 induction prevented the increase in plasma creatinine and in superoxide in both the cortex and medulla compared to untreated rats with acute kidney injury. This protective effect of heme oxygenase-1 was associated with increased anti-apoptotic proteins Bcl-2 and Bcl-xl and a decrease of pro-apoptotic caspase-3 and caspase-9 along with increased expression of inactive BAX. Our study suggests that increased levels of heme oxygenase-1 are protective against acute kidney injury due to radiocontrast exposure.

Impact of silencing HO-2 on EC-SOD and the mitochondrial signaling pathway

The contribution of heme oxygenase HO-2, the primary source of bilirubin and carbon monoxide (CO) under physiological conditions, to the regulation of vascular function has remained largely unexplored. Using siRNA HO-2, we examined the effect of suppressed levels of HO-2 on vascular antioxidant and survival proteins. In vivo HO-2 siRNA treatment decreased the basal levels of EC-SOD, pAKT proteins (serine-473 and threonine-308), without changing Akt protein expression. HO-2 siRNA treatment increased 3-nitrotyrosine (3-NT) and apoptotic signaling kinase-1 (ASK-1) (P < 0.01). HO activity was decreased by the use of siRNA HO-2. We extended these studies to the mitochondria, examining for the presence of HO-1 and its role in the regulation of pro- and anti-apoptotic proteins. HO activity was increased by the administration of CoPP resulting in the translocation of HO-1 into the mitochondria, mainly to the inner face of the mitochondrial inner membrane. These findings suggest that HO-2 is critical in the maintenance of heme homeostasis and also the regulation of apoptosis by controlling levels of EC-SOD, Akt, 3-NT, and ASK-1. In addition, localization of HO-1 in the mitochondrial compartment plays a critical role in mitochondria-mediated apoptosis.

Penetrating capacity of human spermatozoa cool preserved in electrolyte-free solution

OBJECTIVE

To evaluate whether human spermatozoa preserved in electrolyte-free (EF) solution at 4 degrees C possess normal penetrating capacity.

STUDY DESIGN

The acrosomal status of human spermatozoa cool preserved in EF solution was evaluated before preservation and before and after reinitiation by using chlortetracycline staining. The zona-free hamster egg sperm penetration test was performed using spermatozoa cool preserved in EF solution.

RESULTS

The percentages of capacitated and acrosome-reacted spermatozoa cool preserved in EF solution before reinitiation were similar to those of fresh spermatozoa, but they significantly increased after reinitiation. The penetration rate and fertility index of spermatozoa cool preserved in EF solution were comparable to those of fresh spermatozoa (48.3% vs. 50.8% and 1.37 +/- 0.15 vs. 1.29 +/- 0.10, respectively).

CONCLUSION

Human spermatozoa cool preserved in EF solution for one week can possess as much penetrating capacity as fresh spermatozoa.

Regulation of human heme oxygenase in endothelial cells by using sense and antisense retroviral constructs

Our objective was to determine whether overexpression and underexpression of human heme oxygenase (HHO)-1 could be controlled on a long-term basis by introduction of the HO-1 gene in sense (S) and antisense (AS) orientation with an appropriate vector into endothelial cells. Retroviral vector (LXSN) containing viral long terminal repeat promoter-driven human HO-1 S (LSN-HHO-1) and LXSN vectors containing HHO-1 promoter (HOP)-controlled HHO-1 S and AS (LSN-HOP-HHO-1 and LSN-HOP-HHO-1-AS) sequences were constructed and used to transfect rat lung microvessel endothelial cells (RLMV cells) and human dermal microvessel endothelial cells (HMEC-1 cells). RLMV cells transduced with HHO-1 S expressed human HO-1 mRNA and HO-1 protein associated with elevation in total HO activity compared with nontransduced cells. Vector-mediated expression of HHO-1 S or AS under control of HOP resulted in effective production of HO-1 or blocked induction of endogenous human HO-1 in HMEC-1 cells, respectively. Overexpression of HO-1 AS was associated with a long-term decrease (45%) of endogenous HO-1 protein and an increase (167%) in unmetabolized exogenous heme in HMEC-1 cells. Carbon monoxide (CO) production in HO-1 S- or AS-transduced HMEC-1 cells after heme treatment was increased (159%) or decreased (50%), respectively, compared with nontransduced cells. HO-2 protein levels did not change. These findings demonstrate that HHO-1 S and AS retroviral constructs are functional in enhancing and reducing HO activity, respectively, and thus can be used to regulate cellular heme levels, the activity of heme-dependent enzymes, and the rate of heme catabolism to CO and bilirubin.

Functional expression and stabilization of horseradish peroxidase by directed evolution in Saccharomyces cerevisiae

Biotechnology applications of horseradish peroxidase (HRP) would benefit from access to tailor-made variants with greater specific activity, lower K(m) for peroxide, and higher thermostability. Starting with a mutant that is functionally expressed in Saccharomyces cerevisiae, we used random mutagenesis, recombination, and screening to identify HRP-C mutants that are more active and stable to incubation in hydrogen peroxide at 50 degrees C. A single mutation (N175S) in the HRP active site was found to improve thermal stability. Introducing this mutation into an HRP variant evolved for higher activity yielded HRP 13A7-N175S, whose half-life at 60 degrees C and pH 7.0 is three times that of wild-type (recombinant) HRP and a commercially available HRP preparation from Sigma (St. Louis, MO). The variant is also more stable in the presence of H(2)O(2), SDS, salts (NaCl and urea), and at different pH values. Furthermore, this variant is more active towards a variety of small organic substrates frequently used in diagnostic applications. Site-directed mutagenesis to replace each of the four methionine residues in HRP (M83, M181, M281, M284) with isoleucine revealed no mutation that significantly increased the enzyme's stability to hydrogen peroxide.

Automated RIBA HCV strip immunoblot assay: a novel tool for the diagnosis of hepatitis C virus infection in hemodialysis patients

Hemodialysis (HD) patients remain a high-risk group for hepatitis C virus (HCV) infection. Serological assays (enzyme-linked immunosorbent assays, ELISAs) are the only tests currently approved by the Food and Drug Administration in the United States for the diagnosis of HCV. The RIBA HCV Strip Immunoblot Assay (SIA) is an established method for supplemental testing of repeat reactive hepatitis C ELISA patients on HD. However, the current manual procedure is labor intensive, requiring subjective band scoring and result interpretation. Recently, the automated CHIRON RIBA HCV Processor System has been designed to perform RIBA supplemental testing. The CHIRON RIBA HCV Processor System consists of a bench-top instrument that provides objective evaluation of the RIBA immunoblot strips, by measuring the light differentially reflected from the developed bands and white background, creating a density of reflectance. The CHIRON RIBA HCV Processor System assesses the intensity of each of the reactive bands in relation to the intensity of the internal control bands on each RIBA HCV strip. Comparison between processor and manual protocols was performed using a large (n = 200) cohort of ELISA 3.0 HCV negative and positive patients on maintenance HD. The test characteristics of RIBA HCV 3.0 SIA were identical with manual and automated runs. The relative intensity values of antigenic bands by the CHIRON RIBA HCV 3.0 Processor System between anti-HCV positive and negative patients were significantly different; only 15 of 784 (1.9%) antigenic bands had borderline reactivities. The correlation of test results between manual and automated runs was very high (kappa value 0.989). Among positive results by RIBA HCV 3.0 SIA, there was a strong concordance between manual and automated runs with regard to the pattern of reactivity (kappa value 0.943). The discordant results between manual and automated protocols were attributable to increased variability of antigen scores close to the cutoff value for both tests. In conclusion, the CHIRON RIBA HCV 3.0 Processor System is capable of performing RIBA HCV 3.0 SIA in the HD population accurately with minimal operator involvement. The test characteristics of RIBA HCV 3.0 SIA were identical by manual and automated runs. There was a strong correlation between the results of the manual and automated runs; the few discordant results between the two procedures were mostly due to increased variability of antigen scores close to the cutoff value for both tests. The Centers for Disease Control and Prevention in the USA have recently included chronic HD patients among those persons for whom routine HCV testing is recommended; HCV-infected patients on HD often have a high rate of indeterminate results by manual RIBA technology which is operator dependent for band scoring and result interpretation. The CHIRON RIBA HCV 3.0 Processor System may be very useful for supplemental anti-HCV testing of ELISA repeat reactive specimens in clinical practice within dialysis units.

Activation of the pro-drug ethionamide is regulated in mycobacteria

The anti-tuberculosis drug ethionamide (ETH), which is a structural analog of isoniazid (INH), is known to strongly inhibit mycolic acid synthesis in Mycobacterium tuberculosis. Although several targets have been identified for INH, only speculative information is available concerning ETH. Mutations within the promoter and the coding region of enoyl-acyl carrier protein reductase (InhA) were found to confer resistance to both drugs, thus leading to the impression that INH and ETH may share a common mode of action. However, a notable distinction between the two drugs lies in the lack of cross-resistance in clinical isolates. This may be attributed in part to the fact that the pro-drug INH must be activated via KatG, and no activation step for ETH has yet been described. Here we report the identification of an activator for ETH. The ETH activator (Rv3854c), which we have termed EthA, was found to be homologous to various monooxygenases and induced ETH sensitivity when overexpressed in mycobacteria. Interestingly, the neighboring open reading frame (Rv3855), which was found homologous to transcriptional repressors of the tetR family, led to ETH resistance when overexpressed. In addition, chromosomal inactivation of this gene by transposition led to ETH hypersensitivity. These data strongly suggest that Rv3855, which we have termed EthR, regulates the production of EthA, which subsequently activates the pro-drug ETH. This study opens up new avenues of research relating to ETH activation in mycobacteria, possibly leading to an improved efficacy of ETH and to the generation of new anti-mycobacterial agents.

CXC chemokine receptor 3 expression on CD34(+) hematopoietic progenitors from human cord blood induced by granulocyte-macrophage colony-stimulating factor: chemotaxis and adhesion induced by its ligands, interferon gamma-inducible protein 10 and monokine induced by interferon gamma

CXC chemokine receptor 3 (CXCR3), which is known to be expressed predominately on memory and activated T lymphocytes, is a receptor for both interferon gamma (IFN-gamma)-inducible protein 10 (gamma IP-10) and monokine induced by IFN-gamma (Mig). We report the novel finding that CXCR3 is also expressed on CD34(+) hematopoietic progenitors from human cord blood stimulated with granulocyte-macrophage colony-stimulating factor (GM-CSF) but not on freshly isolated CD34(+) progenitors. Freshly isolated CD34(+) progenitors expressed low levels of CXCR3 messenger RNA, but this expression was highly up-regulated by GM-CSF, as indicated by a real-time quantitative reverse transcriptase-polymerase chain reaction technique. gamma IP-10 and Mig induced chemotaxis of GM-CSF-stimulated CD34(+) progenitors by means of CXCR3, since an anti-CXCR3 monoclonal antibody (mAb) was found to block gamma IP-10-induced and Mig-induced CD34(+) progenitor chemotaxis. These chemotactic attracted CD34(+) progenitors are colony-forming units-granulocyte-macrophage. gamma IP-10 and Mig also induced GM-CSF-stimulated CD34(+) progenitor adhesion and aggregation by means of CXCR3, a finding confirmed by the observation that anti-CXCR3 mAb blocked these functions of gammaIP-10 and Mig but not of chemokine stromal cell-derived factor 1 alpha. gamma IP-10-induced and Mig-induced up-regulation of integrins (CD49a and CD49b) was found to play a crucial role in adhesion of GM-CSF-stimulated CD34(+) progenitors. Moreover, gamma IP-10 and Mig stimulated CXCR3 redistribution and cellular polarization in GM-CSF-stimulated CD34(+) progenitors. These results indicate that CXCR3-gamma IP-10 and CXCR3-Mig receptor-ligand pairs, as well as the effects of GM-CSF on them, may be especially important in the cytokine/chemokine environment for the physiologic and pathophysiologic events of differentiation of CD34(+) hematopoietic progenitors into lymphoid and myeloid stem cells, subsequently immune and inflammatory cells. These processes include transmigration, relocation, differentiation, and maturation of CD34(+) hematopoietic progenitors. (Blood. 2000;96:1230-1238)

Chemokine stromal cell-derived factor 1alpha activates basophils by means of CXCR4

BACKGROUND

The CXC chemokine receptor 4 (CXCR4) is predominantly expressed on inactivated naive T lymphocytes, B lymphocytes, dendritic cells, and endothelial cells. CXC chemokine stromal cell-derived factor 1alpha (SDF-1alpha) is the only known ligand for CXCR4. To date, the CXCR4 expression and function of SDF-1alpha in basophils are unknown.

OBJECTIVE

The purpose of this study was to investigate the expression of CXCR4 and functions of SDF-1alpha in basophils and to characterize the role of the CXCR4-SDF-1alpha receptor ligand pair in the allergic inflammation.

METHODS

Basophil purification, flow cytometry, real-time quantitative RT-PCR assay, Northern blotting, intracellular free Ca(2+) change, chemotaxis assay, and histamine release assay were used.

RESULTS

CXCR4 is abundantly expressed on peripheral blood resting basophils (91%). Likewise, CXCR4 messenger (m)RNA is expressed in resting basophils (3.2 x 10(3) copies per 2 x 10(2) cells). The existence of CXCR4 mRNA was also confirmed in basophils by means of Northern blot analysis. SDF-1alpha induces an increase in intracellular free Ca(2+) in basophils. SDF-1alpha activates basophils to chemotaxis (chemotactic index = 3.8) and histamine release (36% of total content) through CXCR4 on the cells. The chemokines SDF-1alpha, eotaxin, RANTES, monocyte chemoattractant protein (MCP) 1, and macrophage inflammatory protein (MIP) 1alpha have been demonstrated at different potencies in induction of chemotaxis (eotaxin > SDF-1alpha > RANTES congruent with MCP-1 >> MIP-1alpha) and histamine release (MCP-1 congruent with SDF-1alpha > eotaxin > RANTES > MIP-1alpha). The optimal concentration seen for SDF-1alpha effects (chemotaxis and histamine release) on basophils was 100 ng/mL.

CONCLUSION

These results indicate that the CXCR4-SDF-1alpha receptor ligand pair may be important for the recruitment and activation of the basophils, which is a characteristic effector cell of the allergic inflammation.

Humoral immune response to hepatitis C after liver transplantation: assessment of a new recombinant immunoblot assay

OBJECTIVE

The immune control of infection with hepatitis C virus (HCV) is poorly understood; vigorous antibody responses to viral proteins seem to coexist with the virus and thus whether they are neutralizing remains controversial. HCV-related liver failure is the leading indication for orthotopic liver transplantation (OLT) worldwide. Attenuated antibody responses in immunosuppressed patients and decreased reliability compared to assessment of HCV RNA has hampered the use of antibody testing post-OLT. The goals of this current analysis were twofold: to determine the sensitivity of a prototype strip immunoblot assay (RIBA 3.0, Chiron Diagnostics) for the diagnosis of HCV post-OLT; to determine if there was a correlation between antibody response and severity of histological recurrence.

METHODS

The study was comprised of 76 HCV-positive individuals divided into three patient groups: liver allograft recipients with evidence of mild or no histological recurrence (n = 52), liver allograft recipients with evidence of severe HCV recurrence and allograft cirrhosis (n = 12), and nontransplant patients being enrolled in an induction interferon trial (n = 12). All transplant patients had histological follow-up of at least 1 yr.

RESULTS

Sixty of the 64 (94%) HCV-positive OLT recipients had 1+ reactivity to two or more recombinant antigens; three of the patients who lacked a detectable response had minimal histological recurrence and one had severe recurrence. All nontransplant patients demonstrated 4+ reactivity to at least two antigens, and 55/64 (86%) OLT recipients demonstrated this same level of reactivity. Seven of the nine patients lacking this high level of reactivity had evidence of minimal recurrence. Furthermore, the mean (+/- SEM) level of antibody reactivity for c100 (p = 0.04) and NS5 (p = 0.01) were significantly lower for patients with mild recurrence after OLT, compared to the other groups. The level of antibody reactivity was unrelated to HCV genotype or viral load.

CONCLUSIONS

The recently developed RIBA 3.0 assay for detection of antibodies to HCV appears to be highly sensitive for the diagnosis of HCV post-OLT. In general, the level of antibody reactivity was comparable in the transplant patients and in nonimmunosuppressed controls. The pathogenic implications of the relatively diminished humoral response in patients with mild recurrence post-OLT are discussed.

Performance of second- and third-generation RIBAs for confirmation of third-generation HCV EIA-reactive blood donations. Retrovirus Epidemiology Donor Study

BACKGROUND

Licensure of an enhanced HCV screening assay (HCV 3.0 EIA) without concurrent licensure of a complementary supplemental assay (i.e., RIBA HCV 3.0 strip immunoblot assay [RIBA-3]) decoupled screening and supplemental testing. In March 1998, the FDA Center for Biologics Evaluation and Research (CBER) recommended the use of RIBA-3 on RIBA HCV 2.0 strip immunoblot assay (RIBA-2)-indeterminate units screened with HCV EIA 3.0.

STUDY DESIGN AND METHODS

The sensitivity of RIBA-2 and RIBA-3 was compared in tests on HCV 3.0 EIA-repeatably reactive (RR) units identified immediately after the implementation of HCV 3.0 EIA screening. Two protocols were evaluated: parallel testing of HCV 3.0 EIA-RR units by RIBA-2 and RIBA-3 and reflex testing of HCV 3.0 EIA-RR and RIBA-3-confirmed-positive units by RIBA-2. All specimens with discordant RIBA-2 and RIBA-3 results and a representative sampling with concordant RIBA results were tested by PCR.

RESULTS

In the parallel testing protocol, 99,777 donations were screened, with 245 HCV 3.0 EIA-RR specimens included in the study. Of 166 RIBA-2-positive samples, 165 tested positive in RIBA-3 (1 sample reacted to the control superoxide dismutase antigen in RIBA-3). Thirty-two (74%) of 43 RIBA-2-indeterminate specimens and 4 (11%) of 36 RIBA-2-negative specimens tested positive in RIBA-3. HCV RNA was identified in 5 (16%) of 32 RIBA-2-indeterminate/RIBA-3-positive donations, as well as in 26 (70%) of 37 concordant RIBA-2/RIBA-3-positive donations. In the reflex testing protocol, 292,459 donations were screened, with 709 HCV 3.0 EIA-RR specimens included in the study. RIBA-3 testing yielded 517 (73%) positive specimens, of which 50 (9.7%) tested indeterminate and 15 (2.9%) tested negative in RIBA-2. Among the RIBA-discordant specimens, 10 (20%) RIBA-2-indeterminate specimens and 1 (7%) RIBA-2-negative specimens tested positive in PCR; in comparison, 60 (77%) of 78 concordant RIBA-2/RIBA-3-positive units tested positive in PCR.

CONCLUSIONS

RIBA-3 is significantly more sensitive than RIBA-2 in testing of HCV 3.0 EIA-screened donations. During the review process of this manuscript, the FDA licensed the RIBA-3 test.

CXCR3 expression and activation of eosinophils: role of IFN-gamma-inducible protein-10 and monokine induced by IFN-gamma

CXC chemokine receptor 3 (CXCR3), predominately expressed on memory/activated T lymphocytes, is a receptor for both IFN-gamma-inducible protein-10 (gamma IP-10) and monokine induced by IFN-gamma (Mig). We report a novel finding that CXCR3 is also expressed on eosinophils. gamma IP-10 and Mig induce eosinophil chemotaxis via CXCR3, as documented by the fact that anti-CXCR3 mAb blocks gamma IP-10- and Mig-induced eosinophil chemotaxis. gamma IP-10- and Mig-induced eosinophil chemotaxis are up- and down-regulated by IL-2 and IL-10, respectively. Correspondingly, CXCR3 protein and mRNA expressions in eosinophils are up- and down-regulated by IL-2 and IL-10, respectively, as detected using flow cytometry, immunocytochemical assay, and a real-time quantitative RT-PCR technique. gamma IP-10 and Mig act eosinophils to induce chemotaxis via the cAMP-dependent protein kinase A signaling pathways. The fact that gamma IP-10 and Mig induce an increase in intracellular calcium in eosinophils confirms that CXCR3 exists on eosinophils. Besides induction to chemotaxis, gamma IP-10 and Mig also activate eosinophils to eosinophil cationic protein release. These results indicate that CXCR3-gamma IP-10 and -Mig receptor-ligand pairs as well as the effects of IL-2 and IL-10 on them may be especially important in the cytokine/chemokine environment for the pathophysiologic events of allergic inflammation, including initiation, progression, and termination in the processes.

Effects of preservation of mouse spermatozoa in electrolyte-free solution at 4 degrees C on the outcome of mouse in vitro fertilization

PURPOSE

The aim was to assess the fertilizing capacity of spermatozoa cool-preserved in electrolyte-free (EF) solution.

METHODS

Mouse spermatozoa were cool-preserved in EF solution and the acrosomal status of the spermatozoa was compared before and after preservation using chlortetracycline stain. Mouse oocytes were inseminated by spermatozoa cool-preserved in EF solution for 2, 4, or 7 days and fertilization and blastocyst rates were evaluated.

RESULTS

Acrosomal status of spermatozoa cool-preserved in EF solution was not different from spermatozoa before preservation, but the capacitated and acrosome-reacted spermatozoa significantly increased after reinitiation. Cool-preservation in EF solution for up to 4 days did not affect fertilization rate. Blastocyst rate of embryos derived from spermatozoa cool-preserved for 4 or 7 days in EF solution was significantly lower than that of embryos derived from fresh spermatozoa.

CONCLUSIONS

Mouse spermatozoa cool-preserved in EF solution possesses as much fertilizing capacity as fresh spermatozoa. However, prolonged preservation affects the embryonic development.

Serotyping strip immunoblot assay for assessing hepatitis C virus strains in dialysis patients

Recent accumulated evidence shows that dialysis patients are a high-risk group for hepatitis C virus (HCV) infection. Assessment of HCV genotype distribution among dialysis patients may be important because specific viral genotypes are associated with different clinical manifestations, disease progression, and response to antiviral therapy. However, polymerase chain reaction-based methods are cumbersome and unsuitable for analyzing large cohorts of dialysis patients with HCV. Instead, this information can be obtained by using a novel recombinant immunoblot assay (RIBA) recently developed for determining HCV serotype. The RIBA HCV serotyping strip immunoblot assay (SIA; Chiron Corporation, Emeryville, CA), is based on an immunoblot strip with five lanes of immobilized serotype-specific HCV peptides from the nonstructural (NS4) and core regions of the genomes of HCV types 1, 2, and 3. HCV serotype is deduced by determining the greatest intensity of reactivity to the NS4 serotype-specific HCV peptide band in relation to the internal control band (human immunoglobulin G) intensity on each strip. HCV core peptide reactivity is used only in the absence of NS4 reactivity. We compared RIBA HCV serotyping SIA with genotyping using sera from a large (n = 107) cohort of HCV-infected patients undergoing chronic hemodialysis (HD). We successfully serotyped 79 of 107 patients (74%) undergoing HD. We found a remarkable concordance (65 of 70 results; 93%) between RIBA HCV serotyping SIA and genotyping (line probe assay [LiPA]) techniques (kappa = 0.786) with sera from viremic patients infected with a known genotype. Only 5 of 70 patients (7%) had apparently discordant results. In a subset of patients (28 of 107 patients; 26%) not typed by RIBA HCV serotyping SIA, most (24 of 28 patients; 86%) were successfully genotyped by LiPA technology. It was possible to assess serotype reactivity in some patients (9 of 107 patients; 7%) who could not be genotyped. The distribution of HCV serotypes was associated with the antibody response against HCV proteins and the patterns of reactivity by RIBA HCV 2.0 SIA. In conclusion, (1) we found good agreement between serotyping and genotyping methods in our large cohort of dialysis patients infected with HCV; (2) the impaired immunocompetence conferred by uremia may limit serotyping analysis in some HCV-infected patients undergoing HD; (3) RIBA HCV serotyping SIA may be useful in tracking transmission routes for HD patients who cleared the virus and have only anti-HCV antibody; and (4) the distribution of HCV serotypes was associated with the antibody response against HCV proteins and the patterns of reactivity by RIBA HCV 2.0 SIA. Assessment of HCV strains appears to be very useful in the routine clinical activity of nephrologists within HD units because consistent biological differences among HCV strains exist. RIBA serotyping SIA is a simple, inexpensive, and highly reproducible assay to obtain information about HCV types in the HD setting.

Eotaxin induces degranulation and chemotaxis of eosinophils through the activation of ERK2 and p38 mitogen-activated protein kinases

Eotaxin and other CC chemokines acting via CC chemokine receptor-3 (CCR3) are believed to play an integral role in the development of eosinophilic inflammation in asthma and allergic inflammatory diseases. However, little is known about the intracellular events following agonist binding to CCR3 and the relationship of these events to the functional response of the cell. The objectives of this study were to investigate CCR3-mediated activation of the mitogen-activated protein (MAP) kinases extracellular signal-regulated kinase-2 (ERK2), p38, and c-jun N-terminal kinase (JNK) in eosinophils and to assess the requirement for MAP kinases in eotaxin-induced eosinophil cationic protein (ECP) release and chemotaxis. MAP kinase activation was studied in eotaxin-stimulated eosinophils (more than 97% purity) by Western blotting and immune-complex kinase assays. ECP release was measured by radioimmunoassay. Chemotaxis was assessed using Boyden microchambers. Eotaxin (10(-11) to 10(-7) mol/L) induced concentration-dependent phosphorylation of ERK2 and p38. Phosphorylation was detectable after 30 seconds, peaked at about 1 minute, and returned to baseline after 2 to 5 minutes. Phosphorylation of JNK above baseline could not be detected. The kinase activity of ERK2 and p38 paralleled phosphorylation. PD980 59, an inhibitor of the ERK2-activating enzyme MEK (MAP ERK kinase), blocked phosphorylation of ERK2 in a concentration-dependent manner. The functional relevance of ERK2 and p38 was studied using PD98 059 and the p38 inhibitor SB202 190. PD98 059 and SB202 190 both caused inhibition of eotaxin-induced ECP release and chemotaxis. We conclude that eotaxin induces a rapid concentration-dependent activation of ERK2 and p38 in eosinophils and that the activation of these MAP kinases is required for eotaxin-stimulated degranulation and directed locomotion. (Blood. 2000;95:1911-1917)

CXC chemokine receptor 4 expression and stromal cell-derived factor-1alpha-induced chemotaxis in CD4+ T lymphocytes are regulated by interleukin-4 and interleukin-10

We report that interleukin (IL)-4 and IL-10 can significantly up- or down-regulate CXC chemokine receptor 4 (CXCR4) expression on CD4+ T lymphocytes, respectively. Stromal cell-derived factor-1alpha (SDF-1alpha)-induced CD4+ T-lymphocyte chemotaxis was also correspondingly regulated by IL-4 and IL-10. IL-4 and IL-10 up- or down-regulated CXCR4 mRNA expression in CD4+ T lymphocytes, respectively, as detected by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). Scatchard analysis revealed a type of CXCR4 with affinity (Kd approximately 6.3 nM), and approximately 70,000 SDF-1alpha-binding sites per cell, among freshly isolated CD4+ T lymphocytes, and two types of CXCR4 with different affinities (Kd1 approximately 4.4 nM and Kd2 approximately 14.6 nM), and a total of approximately 130,000 SDF-1alpha-binding sites per cell, among IL-4-stimulated CD4+ T lymphocytes. The regulation of CXCR4 expression in CD4+ T lymphocytes by IL-4 and IL-10 could be blocked by a selective inhibitor of protein kinase (staurosporine) or by a selective inhibitor of cAMP- and cGMP-dependent protein kinase (H-8), indicating that these cytokines regulate CXCR4 on CD4+ T lymphocytes via both cAMP and cGMP signalling pathways. The fact that cyclosporin A or ionomycin were able to independently change the CXCR4 expression and block the effects of IL-4 and IL-10 on CXCR4 expression implied that the capacity of IL-4 and IL-10 to regulate CXCR4 on CD4+ T lymphocytes is not linked to calcium-mobilization stimulation. These results indicate that the effects of IL-4 and IL-10 on the CXCR4-SDF-1 receptor-ligand pair may be of particular importance in the cytokine/chemokine environment concerning the inflammatory processes and in the progression of human immunodeficiency virus (HIV) infection.

Light inhibits rifampicin inactivation and reduces rifampicin resistance due to a cloned mycobacterial ADP-ribosylation gene

Rifampicin is a principal drug used to combat infections by mycobacteria and related organisms. Most strains of Mycobacterium are able to inactivate this antibiotic by ribosylation via an ADP-ribosylated intermediate. We found that this inactivation was inhibited by light at levels similar to those prevailing in laboratory environments. Rifampicin resistance arising from the cloned ADP-ribosyl transferase was also greatly diminished at these light levels. The cloned Rhodococcus equi monooxygenase which inactivates this antibiotic by a different mechanism was, in contrast, not inhibited by light.

[Measurement of macrophage colony-stimulating factor during in-vitro fertilization and embryo transfer cycles]

OBJECTIVE

To explore the influences of macrophage colony-stimulating factor (M-CSF) on follicle development, ovulation, fertilization and embryo quality during in-vitro fertilization and embryo transfer (IVF-ET) cycles.

METHODS

36 patients underwent 54 cycles of controlled ovarian hyperstimulation by gonadotropin-releasing hormone agonist-human menopausal goudotropin-human chorionic gonadotropin for IVF-ET program. M-CSF concentrations in serum were measured at early follicular phase, mid-follicular phase and the day of oocyte retrieval by enzyme-linked immunosorbent assay. Follicular fluid (FF) on the day of egg retrieval was also measured for M-CSF concentration.

RESULTS

M-CSF concentration in serum gradually increased throughout ovarian hyperstimulation and reached a peak on the day of oocyte retrieval. M-CSF concentration in FF was significantly higher than that in serum on the same day (P < 0.01). The M-CSF concentration in FF from follicles where oocytes could be retrieved, fertilized or with a diameter > or 16 mm, volume > or 2 ml, was significantly higher than those from follicles where oocyte could not be retrieved, fertilized or with a diameter < 16 mm, volume < 2 ml, respectively (P < 0.01). However, there was no significant difference in M-CSF concentration of FF between high and low embryo grade groups (P > 0.05).

CONCLUSIONS

M-CSF may play an important role as an intraovarian regulator in the process of follicle development, maturation and ovulation. Therefore, M-CSF may exert an effect on fertilization process but not on the embryo quality.

Lookback on donors who are repeatedly reactive on first-generation hepatitis C virus assays:justification and rational implementation

BACKGROUND

The purpose of this study was to explore strategies to minimize the number of unwarranted consignee notifications resulting from hepatitis C virus (HCV) first-generation (single-antigen) enzyme immunoassay (EIA 1.0) targeted lookback.

STUDY DESIGN AND METHOD

The four blood centers participating in this study contributed data on 3753 HCV EIA 1.0-repeatably reactive (RR) donations. The analysis focused on 1) statistical evaluation of HCV EIA 1.0 signal-to-cutoff (S/CO) ratios versus HCV second-generation recombinant immunoblot assay (RIBA 2.0) interpretation from all participating blood centers and 2) RNA testing using transcription-mediated amplification on all HCV EIA 1.0 RR/RIBA 2. 0-positive or -indeterminate specimens and a subset of RIBA 2. 0-negative donations for which specimens were available.

RESULTS

Analysis of HCV EIA 1.0 S/CO ratios versus RIBA 2.0 indicated that 1180 (89%) of 1326 RIBA 2.0-positive specimens had an S/CO ratio >2. 5, while 146 (11%) had a ratio </=2.5. In contrast, of 2253 RIBA 2. 0-negative specimens, 299 (13%) had an S/CO ratio >2.5, while 1954 (87%) had a ratio </=2.5. Of 248 HCV EIA 1.0-RR/RIBA 2.0-positive samples with stored specimens available for additional testing, 198 (80%) were HCV RNA positive; 15 (7.5%) of these specimens had an S/CO ratio </=2.5, while 183 (92%) had a ratio >2.5. HCV RNA was detected in only 2 (1.5%) of 137 HCV EIA 1.0-RR/RIBA 2.0-negative specimens: 1 of these 2 specimens had an S/CO >2.5, while the other had an S/CO </=2.5.

CONCLUSION

A highly significant (<0.0001) correlation was found between the S/CO ratio on HCV EIA 1.0- and RIBA 2.0-positive or -negative results. An S/CO ratio >2.5 yielded an 89- percent sensitivity for RIBA 2.0-positive specimens, and donations with an S/CO ratio >2.5 had a 75-percent probability of being RIBA 2.0 positive. A policy recommendation to use the S/CO ratio to triage lookback would prevent unwarranted notification of 87 percent of recipients of blood from RIBA 2.0-negative donors and would result in a failure to notify only 5 to 10 percent of recipients potentially exposed to infectious units.

Distinct effect of retroviral-mediated IFN-alpha gene transfer on human erythroleukemic and CD34+ cell growth and differentiation

Human interferon-alpha (IFN-alpha) has been used in the management of leukemia, but its diverse adverse effects may influence the ability of IFN-alpha to treat this disease. We constructed two retroviral vectors, LSN-IFN-alpha and LNC-IFN-alpha, in which IFN-alpha cDNA was driven by viral LTR and CMV promoters, respectively. After transduction into the PA317 and PG13 retroviral packaging cells, high titers of retrovirus were produced and were used to infect K562 and human BM CD34+ hematopoietic cells. The IFN-alpha gene expression in transduced K562 cells was confirmed by Northern blot, RT-PCR, RIA, and biologic assay. Cell proliferation and cell viability in IFN-alpha-transduced K562 cells were significantly suppressed as compared with control K562 cells. Although the IFN-alpha expression in K562 cells did not affect BCR/ABL expression, it apparently upregulated the production of adhesion molecules (VLA-4 and Mac-1). We evaluated the effect of IFN-alpha gene transfer on human CD34+ cells infected with LSN-IFN-alpha retrovirus with the aid of fibronectin (FN) fragment CH-296 and growth factors. RIA showed that IFN-alpha-transduced CD34+ cells produced 72.2+/-15 U/ml of IFN-alpha compared with 4.3+/-1.2 U/ml in control CD34+ cells. Methylcellulose clonogenic assay indicated that IFN-alpha-transduced CD34+ cells produced similar numbers of burst-forming units-erythrocytes (BFU-E)/colony-forming units-GM (CFU-GM) colonies as compared with control CD34+ cells. Selected colonies expressed IFN-alpha and neo(r) mRNA, as measured by RT-PCR. These studies indicate that retrovirus-mediated IFN-alpha gene transfer may provide a useful tool for studying the effect of IFN-alpha gene transfer on leukemic cells and long-lived CD34+ cells.

Human CD34+ hematopoietic cells transduced by retrovirus-mediated interferon alpha gene maintains regeneration capacity and engraftment in NOD/SCID mice

To achieve long-term expression of human interferon alpha-5 (IFNalpha) gene in the bone marrow (BM) hematopoietic microenvironment, replication-deficient retroviral vector LSN-IFNalpha was used to deliver the IFNalpha gene into human BM CD34+ cells. After fibronectin-facilitated transduction, a fraction of CD34+ cells was plated in methylcellulose medium with or without G418 to assess transduction efficiency and the effect of IFNalpha gene transfer on colony formation. Colony-forming assay in the presence of G418 (400 microg/mL) revealed that 41% CFU-GM colonies are G418 resistant after infection with LSN-IFNalpha retrovirus. There was no significant difference in CFU-GM/BFU-E colony formation among IFNalpha gene-transduced CD34+ cells, control vector (LXSN) transduced-CD34+ cells and nontransduced CD34+ cells. Another portion of CD34+ cells was grown in liquid medium to measure IFNalpha production. RIA revealed that IFNalpha gene-transduced CD34+ cells produced 72.2 +/- 15.4 U/mL (10(6) cells/24 hours) of IFNalpha compared with 8.3 +/- 2.1 U/mL and 4.3 +/- 1.2 U/mL in LXSN-transduced or nontransduced CD34+ cells, respectively. The remaining portion of transduced CD34+ cells was transplanted into immunodeficient (NOD/SCID) mice to allow analysis of long-term expression of IFNalpha. Transplantation of 1x10(6) CD34+ cells into sublethally irradiated NOD/SCID mice showed that IFNalpha and neo(r) mRNA were detectable in engrafted mouse BM cells for up to 6 months. We conclude that continual local expression of IFNalpha in transduced CD34+ cells does not impair either CD34+ cell growth and differentiation or engraftment and long-term survival in NOD/SCID mice.

Adenovirus and retrovirus mediated interferon alpha gene transfer into CD34+ cells maintains regeneration capacity and enhances adhesion molecules in K562 cells

BACKGROUND

Systemic administration of interferon-alpha (IFN-alpha) results in cytogenetic remissions and enhanced survival in a significant percentage of patients with chronic mylogenous leukemia (CML) and lymphoma. However, this treatment is associated with deleterious toxic effects. Gene transfer of the IFN-alpha gene into hematopoietic progenitors represents a novel strategy to deliver high concentrations of IFN-alpha to a local area.

METHODS

We compared the effect of the transfer of the IFN-alpha gene on the cell growth and differentiation of several CD34+ cells in culture and in a NOD/SCID animal model, using adenovirus and retrovirus constructs.

RESULTS

Transient local expression of the IFN-alpha gene using an adenovirus vector was associated with normal proliferation of CD34+ progenitors as measured by a colony forming unit of granulocyte-macrophage (CFU-GM) growth. Flow cytometric determination revealed that there was no significant difference in viability of these cells for 24-hour transduction periods. Reverse transcriptase/polymerase chain reaction (RT-PCR) analysis of RNA from CD34+ harvested CFU-GM progenitors demonstrated expression of IFN-alpha mRNA; radioimmunoassay (RIA) revealed that transduced cells secreted substantial levels of IFN-alpha protein. Furthermore, we constructed a retroviral vector in which IFN-alpha cDNA was driven by a viral LTR promoter to evaluate the effect of permanent IFN-alpha gene expression on cell growth. Retroviral packaging cells PA317 with high titers of retrovirus were produced and used to infect CD34+ and K562 cells. RIA showed that IFN-alpha-transduced CD34+ cells (with the aid of fibronectin fragment CH-296) produced approximately 400 units of IFN-alpha protein compared to CD34+ cells, or cells transduced with empty vector. IFN-alpha transduced CD34+ generated similar numbers of CFU-GM colonies as compared to control CD34+ cells. Engraftment of CD34+ cells transduced with IFN-alpha gene in NOD/SCID mice was successful for the first 30 days. Additionally, we studied the effect of local IFN-alpha expression on the cellular adhesion molecules, VLA-4, Mac-1, ICAM-1, and L-selectin in K562 cells, and human umbilical endothelial vein cells. K562 cells transduced with the IFN-alpha gene expressed a significantly elevated level of VLA-4, Mac-1, and ICAM-1.

CONCLUSIONS

We conclude that expression of the IFN-alpha gene using retrovirus vectors results in an adequate localized expression of IFN-alpha mRNA and protein.