Single Live Cell Imaging of Multidrug Resistance Using Silver Ultrasmall Nanoparticles as Biosensing Probes in Triple-Negative Breast Cancer Cells

Silver ultrasmall nanoparticles (Ag UNPs) (size < 5 nm) were used as biosensing probes to analyze the efflux kinetics contributing to multidrug resistance (MDR) in single live triple-negative breast cancer (TNBC) cells by using dark-field optical microscopy to follow their size-dependent localized surface plasmon resonance. TNBC cells lack expression of estrogen (ER-), progesterone (PR-), and human epidermal growth factor 2 (HER2-) receptors and are more likely to acquire resistance to anticancer drugs due to their ability to transport harmful substances outside the cell. The TNBC cells displayed greater nuclear and cytoplasmic efflux, resulting in less toxicity of Ag UNPs in a concentration-independent manner. In contrast, more Ag UNPs and an increase in cytotoxic effects were observed in the receptor-positive breast cancer cells that have receptors for ER+, PR+, and HER2+ and are known to better respond to anticancer therapies. Ag UNPs accumulated in receptor-positive breast cancer cells in a time-and concentration-dependent mode and caused decreased cellular growth, whereas the TNBC cells due to the efflux were able to continue to grow. The TNBC cells demonstrated a marked increase in survival due to their ability to have MDR determined by efflux of Ag UNPs outside the nucleus and the cytoplasm of the cells. Further evaluation of the nuclear efflux kinetics of TNBC cells with Ag UNPs as biosensing probes is critical to gain a better understanding of MDR and potential for enhancement of cancer drug delivery.

Plasma Environment, Radiation, Structure, and Evolution of the Uranian System (PERSEUS): A Dedicated Orbiter Mission Concept to Study Space Physics at Uranus

The Plasma Environment, Radiation, Structure, and Evolution of the Uranian System (PERSEUS) mission concept defines the feasibility and potential scope of a dedicated, standalone Heliophysics orbiter mission to study multiple space physics science objectives at Uranus. Uranus's complex and dynamic magnetosphere presents a unique laboratory to study magnetospheric physics as well as its coupling to the solar wind and the planet's atmosphere, satellites, and rings. From the planet's tilted and offset, rapidly-rotating non-dipolar magnetic field to its seasonally-extreme interactions with the solar wind to its unexpectedly intense electron radiation belts, Uranus hosts a range of outstanding and compelling mysteries relevant to the space physics community. While the exploration of planets other than Earth has largely fallen within the purview of NASA's Planetary Science Division, many targets, like Uranus, also hold immense scientific value and interest to NASA's Heliophysics Division. Exploring and understanding Uranus's magnetosphere is critical to make fundamental gains in magnetospheric physics and the understanding of potential exoplanetary systems and to test the validity of our knowledge of magnetospheric dynamics, moon-magnetosphere interactions, magnetosphere-ionosphere coupling, and solar wind-planetary coupling. The PERSEUS mission concept study, currently at Concept Maturity Level (CML) 4, comprises a feasible payload that provides closure to a range of space physics science objectives in a reliable and mature spacecraft and mission design architecture. The mission is able to close using only a single Mod-1 Next-Generation Radioisotope Thermoelectric Generator (NG-RTG) by leveraging a concept of operations that relies of a significant hibernation mode for a large portion of its 22-day orbit.

EPHB6 augments both development and drug sensitivity of triple-negative breast cancer tumours

Triple-negative breast cancer (TNBC) tumours that lack expression of oestrogen, and progesterone receptors, and do not overexpress the HER2 receptor represent the most aggressive breast cancer subtype, which is characterised by the resistance to therapy in frequently relapsing tumours and a high rate of patient mortality. This is likely due to the resistance of slowly proliferating tumour-initiating cells (TICs), and understanding molecular mechanisms that control TICs behaviour is crucial for the development of effective therapeutic approaches. Here, we present our novel findings, indicating that an intrinsically catalytically inactive member of the Eph group of receptor tyrosine kinases, EPHB6, partially suppresses the epithelial–mesenchymal transition in TNBC cells, while also promoting expansion of TICs. Our work reveals that EPHB6 interacts with the GRB2 adapter protein and that its effect on enhancing cell proliferation is mediated by the activation of the RAS-ERK pathway, which allows it to elevate the expression of the TIC-related transcription factor, OCT4. Consistent with this, suppression of either ERK or OCT4 activities blocks EPHB6-induced pro-proliferative responses. In line with its ability to trigger propagation of TICs, EPHB6 accelerates tumour growth, potentiates tumour initiation and increases TIC populations in xenograft models of TNBC. Remarkably, EPHB6 also suppresses tumour drug resistance to DNA-damaging therapy, probably by forcing TICs into a more proliferative, drug-sensitive state. In agreement, patients with higher EPHB6 expression in their tumours have a better chance for recurrence-free survival. These observations describe an entirely new mechanism that governs TNBC and suggest that it may be beneficial to enhance EPHB6 action concurrent with applying a conventional DNA-damaging treatment, as it would decrease drug resistance and improve tumour elimination.

Detection of the Acetylcholinesterase Insecticide Resistance Mutation (G328A) in Natural Populations of Ceratitis capitata

Wild Mediterranean fruit fly specimens collected from various regions worldwide were screened for the glycine to alanine (Gly->Ala) point mutation (G328A) in the acetylcholinesterase enzyme, presumably causing resistance to organophosphates. We found that the single nucleotide polymorphism (SNP) responsible for this amino acid change is located at the beginning of exon 6 of the Ccace2 gene. The identification of the exact location of the SNP permitted PCR primer design around this site and direct sequencing of the corresponding genomic region. We detected the resistance allele in natural Mediterranean fruit fly populations from Brazil and Spain, but not from other sites in four continents. The known treatment history of sites suggests that the resistance buildup is linked to organophosphate application in the field. The PCR-based detection provides a screening method useful for monitoring Mediterranean fruit fly insecticide resistance in local populations and improving pest management strategies accordingly.

Transcription factors and th17 cell development in experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE), a widely studied animal model of human central nervous system demyelinating diseases such as multiple sclerosis, is a T-cell-mediated autoimmune disease involving effector T helper (Th) subsets such as Th and Th7. Recently, Th7 cells have been shown to play a major role in many autoimmune and other inflammatory diseases. The development of Th subsets is controlled by a complex network of cytokines and signaling and transcription molecules that act to augment the development of one cell type while restricting the development of other lineages. Here, we review the transcription factors (TFs) that are required for Th17 cell development in EAE and classify them into three types: major or essential such as RORγt and STAT3, an array of helper factors that work in combination with or regulate the expression of the major factors, and regulatory TFs that attenuate the expression of Th17 genes. The plasticity of the Th17 cell lineage is also discussed in relation to the interaction of TFs that play a major role in the development of other Th or regulatory T cell (Treg) lineages such as T-bet and Foxp3 with the Th17 TFs.

Time to viral load suppression in antiretroviral-naive and -experienced HIV-infected pregnant women on highly active antiretroviral therapy: implications for pregnant women presenting late in gestation

OBJECTIVE

To compare time to achieve viral load <400 copies/ml and <1000 copies/ml in HIV-infected antiretroviral (ARV) -naive versus ARV-experienced pregnant women on highly active antiretroviral therapy (HAART).

DESIGN

Retrospective cohort study.

SETTING

Three university medical centers, USA.

POPULATION

HIV-infected pregnant women initiated or restarted on HAART during pregnancy.

METHODS

We calculated time to viral load <400 copies/ml and <1000 copies/ml in HIV-infected pregnant women on HAART who reported at least 50% adherence, stratifying based on previous ARV exposure history.

MAIN OUTCOME MEASURES

Time to HIV viral load <400 copies/ml and <1000 copies/ml.

RESULTS

We evaluated 138 HIV-infected pregnant women, comprising 76 ARV-naive and 62 ARV-experienced. Ninety-three percent of ARV-naive women achieved a viral load < 400 copies/ml during pregnancy compared with 92% of ARV-experienced women (P = 0.82). The median number of days to achieve a viral load < 400 copies/ml in the ARV-naive cohort was 25.0 (range 3.5-133; interquartile range 16-34) days compared with 27.0 (range 8-162.5; interquartile range 18.5-54.3) days in the ARV-experienced cohort (P = 0.02). In a multiple predictor analysis, women with higher adherence (adjusted relative hazard [aRH] per 10% increase in adherence 1.29, 95% confidence interval [CI] 1.08-1.54, P = 0.01) and receiving a non-nucleotide reverse transcriptase inhibitor (NNRTI) -based regimen (aRH 2.48, 95% CI 1.33-4.63, P = 0.01) were more likely to achieve viral load <400 copies/ml earlier. Increased baseline HIV log10 viral load was associated with a later time of achieving viral load <400 copies/ml (aRH 0.60, 95% CI 0.39-0.92, P = 0.02). In a corresponding model of time to achieve viral load <1000 copies/ml, adherence (aRH per 10% increase in adherence 1.79, 95% CI 1.34-2.39, P < 0.001), receipt of NNRTI (aRH 2.95, 95% CI 1.23-7.06, P = 0.02), and CD4 cell count (aRH per 50 count increase in CD4 1.12, 95% CI 1.03-1.22, P = 0.01) were associated with an earlier time to achieve viral load below this threshold. Increasing baseline HIV log10 viral load was associated with a longer time of achieving viral load <1000 copies/ml (aRH 0.54, 95% CI 0.34-0.86, P = 0.01). In multiple predictor models, previous ARV exposure was not significantly associated with time to achieve viral load below thresholds of <400 copies/ml and <1000 copies/ml.

CONCLUSIONS

Pregnant women with ≥50% adherence, whether ARV-naive or ARV-experienced, on average achieve a viral load <400 copies/ml within a median of 26 days and a viral load of <1000 copies/ml within a median of 14 days of HAART initiation. Increased adherence, receipt of NNRTI-based regimen and lower baseline HIV log10 viral load were all statistically significant predictors of earlier time to achieve viral load <400 copies/ml and <1000 copies/ml. Increased CD4 count was statistically significant as a predictor of earlier time to achieve viral load <1000 copies/ml.

Natural history of acoustic neuromas

The growth rate of acoustic neuromas was studied in a series of 50 patients who underwent follow-up imaging studies, since surgery was not performed after the initial diagnostic study or only performed after the follow-up studies. In 50% of the cases the tumor did not grow during the length of the follow-up. In the other patients the growth was less than 50% of the original tumor size in all but four. No correlation was observed between tumor growth, length of the follow-up, and age of the patient. Our results suggest a change in the management of this benign tumor.

Expression and interdependencies of pluripotency factors LIN28, OCT3/4, NANOG and SOX2 in human testicular germ cells and tumours of the testis

OCT3/4, NANOG, SOX2 and, most recently, LIN28 have been identified as key regulators of pluripotency in mammalian embryonic and induced stem cells, and are proven to be crucial for generation of the mouse germ-cell lineage. These factors are a hallmark of certain histological types of germ-cell tumours (GCTs). Here, we report novel information on the temporal and spatial expression pattern of LIN28 during normal human male germ-cell development as well as various types of GCTs. To investigate LIN28 expression, immunohistochemical analyses and quantitative proximity ligation assay-based TaqMan protein assays were applied on snap-frozen and formalin-fixed, paraffin-embedded samples as well as representative cell lines. LIN28 was found in primordial germ cells, gonocytes and pre-spermatogonia, in contrast to OCT3/4 and NANOG, which were found only in the first two stages. LIN28 was also found in all precursor lesions (carcinoma in situ and gonadoblastoma) of type II GCTs, as well as the invasive components seminoma and the non-seminomatous elements embryonal carcinoma and yolk sac tumour. Choriocarcinoma showed a heterogeneous pattern, while teratomas and spermatocytic seminomas (type III GCTs) were negative. This expression pattern suggests that LIN28 is associated with malignant behaviour of type II GCTs. Cell line experiments involving siRNA knockdown of LIN28, OCT3/4 and SOX2 showed that LIN28 plays a role in the maintenance of the undifferentiated state of both seminoma and embryonal carcinoma, closely linked to, and likely upstream of OCT3/4 and NANOG. In conclusion, LIN28 regulates the differentiation status of seminoma and embryonal carcinoma and is likely to play a related role in normal human germ-cell development.

Guidelines on the insertion and management of central venous access devices in adults

Central venous access devices are used in many branched of medicine where venous access is required for either long-term or a short-term care. These guidelines review the types of access devices available and make a number of major recommendations. Their respective advantages and disadvantages in various clinical settings are outlined. Patient care prior to, and immediately following insertion is discussed in the context of possible complications and how these are best avoided. There is a section addressing long-term care of in-dwelling devices. Techniques of insertion and removal are reviewed and management of the problems which are most likely to occur following insertion including infection, misplacement and thrombosis are discussed. Care of patients with coagulopathies is addressed and there is a section addressing catheter-related problems.

EGFR mutations (muts), IHC and FISH status, and chromosome 7 gene copy number combined with pAkt expression as potential predictors of survival in non-small cell lung cancer (NSCLC) patients (pts) treated with gefitinib (GEF)

7182

Background: EGFR and pAkt expression by immunohistochemistry (IHC), muts, and FISH status have been identified as possible molecular predictors for GEF efficacy in NSCLC (Cappuzzo, et. al, JNCI, 2005). The goal of this study was to independently evaluate these findings regarding survival (surv), and to assess the predictive value of mean chromosome 7 copy number/cell (C7). Methods: 150 consecutive Expanded Access Trial pts with >1 week GEF therapy were included for analysis. IHC (present vs not detected) was performed for 87 pts, and 58 pts were analyzed for muts by SSCP, mut-specific PCR, and sequencing. Tissue from 81 pts was evaluated for EGFR and C7 gene copy numbers by fluorescence in situ hybridization (FISH). Results: 150 pts (77 female, 73 male; median (md) age 67; 85 adenocarcinoma) received GEF; md follow-up was 5.8 months (mo). Overall response was 8% (2 CR, 10 PR); 56 pts had stable disease. Md Kaplan-Meier surv was 5.9 mo. IHC revealed that 47/87 pts (54%) had EGFR+, and 36/75 pts (48%) had pAkt + tumors. pAkt+ pts had significantly (sig) longer surv than pAkt− pts (11.4 vs 5.8 mo, p < .05). High polysomy was seen in 36/81 pts (44%) who were designated FISH+; 45 pts were FISH−. EGFR IHC and FISH positivity were not sig associated with surv. C7 was defined as low (<3.6, 63 pts) or high (≥3.6, 18 pts); md surv was 6.6 and 17.1 mo, respectively, p < .01. Muts were found in 17/58 tumors (29%). Md surv for pts with and without muts was 23.8 and 7.9 mo, respectively, p < .07. EGFR IHC− pAkt− pts (18 pts) had sig shorter surv than 57 pts with any pos value (4.7 vs 8.8 mo, p < .02). Double-positive pts had sig longer surv than pts with any neg value. Conclusions: These findings resemble but do not duplicate those reported by Cappuzzo, et al. Additionally, high C7, alone or combined with pAKT, may be an important predictor for GEF efficacy in NSCLC. Further studies of C7, a technically simple and reproducible FISH assay, are warranted.

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Hospital planning for acts of terrorism and other public health emergencies involving children

In today's world the increased potential of terrorist attacks places unique burdens and consequences on health care workers. Hospitals and hospital personnel must now be prepared to react immediately to such events. They must also implement, in advance, policies to protect their own health care personnel while providing care to victims. In this review, we discuss the four major forms of mass casualty terrorism (biological, chemical, nuclear, and thermomechanical) including clinical signs and symptoms for each, the impact on health care personnel, and special considerations for children. We will then outline key principles of hospital preparation with regard to paediatrics in anticipation of such emergencies.

Coprescribing and codispensing of cisapride and contraindicated drugs

CONTEXT

Cisapride, an oral prokinetic drug indicated for the symptomatic treatment of nocturnal heartburn due to gastroesophageal reflux disease, was approved by the US Food and Drug Administration in July 1993. After reports of serious cardiac arrhythmias and deaths during administration of cisapride, most involving concomitant exposure to another drug, a series of label changes and warnings were issued in February 1995, October 1995, June 1998, and June 1999. Cisapride was removed from general distribution in July 2000.

OBJECTIVE

To determine the frequency of contraindicted coprescribing and codispensings, in which cisapride and a contraindicated drug were prescribed or dispensed to the same patient for overlapping periods, and the proportion of contraindicated coprescribing by the same physicians and codispensing by the same pharmacies.

DESIGN AND SETTING

Retrospective study of prescription claims from a managed care organization database for all patients with cisapride prescriptions between July 1993 and December 1998.

PARTICIPANTS

A total of 38 757 adult and pediatric patients who had a cisapride prescription immediately preceded by at least 60 days of insurance eligibility.

MAIN OUTCOME MEASURE

Proportion of cisapride prescriptions or dispensing occurring during the same treatment period as a drug contraindicated at that time prescribed by the same physicians or dispensed by the same pharmacies.

RESULTS

Of 131 485 cisapride prescriptions dispensed after the warnings began, 4414 (3.4%) overlapped with at least 1 drug contraindicated in the labeling at the time of the prescription. Of all overlapping prescription pairs, 2190 (50%) were by the same physicians, 3908 (89%) were by the same pharmacies, and 765 (17%) were dispensed on the same day.

CONCLUSION

Prescriptions dispensed by the same pharmacies accounted for a far higher proportion of contraindicated medication pairs than prescriptions from the same physicians. The pharmacy may be an important and underutilized intervention point to prevent contraindicated drugs from being used together.

Nephrotoxicity after acute severe acetaminophen poisoning in adolescents

OBJECTIVE

To determine the rate of acetaminophen related nephrotoxicity in adolescents who present after acute severe acetaminophen intoxication and to identify potential predictors of this outcome.

STUDY DESIGN

Retrospective analysis of consecutive patients between the ages of 12 and 18 years who were admitted at a tertiary care children's hospital for treatment of acute severe acetaminophen intoxication with N-acetylcysteine. The main outcome measure was the frequency of acetaminophen-related nephrotoxicity, defined as abnormal blood urea nitrogen (>6.4 mmol/L or > 18 mg/dL) and/or elevated creatinine (97.2 micromol/L or > 1.1 mg/dL) in association with one or both of the following: elevated blood pressure (systolic blood pressure > 140 mm Hg/diastolic blood pressure >85) or abnormal urinalysis (urinalysis with hematuria or proteinuria). Statistical analyses used were measures of central tendency, Student's t-test, Mann-Whitney, and multivariate logistic regression.

RESULTS

Fourty-five patients were included. Acetaminophen-related nephrotoxicity occurred in 4 (8.9%) cases. One victim developed severe renal injury in association with elevated hepatic transaminases. Intergroup analyses revealed no statistically significant association between acetaminophen-related nephrotoxicity and amount/kg of acute severe acetaminophen ingested, delay in treatment with N-acetylcysteine, or measures of hepaticfunction.

CONCLUSIONS

Acetaminophen-related nephrotoxicity occurred in 8.9% [95% CI: 4.52, 20.48] of children with severe overdose. There are no obvious predictors of this complication of acetaminophen overdose. Because the occurrence of renal injury can not be predicted, serial blood pressure, blood urea nitrogen/creatinine, and urinalysis should be considered an integral part of the management of children with acute, severe acetaminophen intoxication.

Harris Galante cementless acetabular replacement in avascular necrosis

We describe the results of 76 total arthroplasties of the hip for stage-III or stage-IV avascular necrosis of the femoral head. Harris Galante Porous cups were used in 63 patients between 1986 and 1994 and followed prospectively. We reviewed 70 hips with a follow-up of more than five years (mean 7.6). At the latest review the mean Harris Hip Score had improved from a preoperative value of 29 +/- 14.7 to 94 +/- 6.8. Radiologically, there was no evidence of acetabular migration. The rate of revision for the femoral component was 8.6%, three being undertaken for loosening and three to allow downsizing of the femoral head. The rate of revision for the acetabular component was 7.1% (five cups). At the time of revision none of the cups was clinically loose, and only required the liner to be changed. The rate of complications was low with no case of deep infection or dislocation, but nine of the 76 hips (11.8%) showed grade-III heterotopic ossification. Previous studies of patients undergoing cemented total hip arthroplasty for the treatment of advanced avascular necrosis have indicated a high incidence of loosening of the acetabular component. Our findings show good medium-term results using the Harris Galante Porous cup for acetabular reconstruction, together with a variety of cemented femoral components, for the treatment of this difficult problem.

Tandem zinc-finger gene families in mammals: insights and unanswered questions

Evidence for the remarkable conservation of mammalian genomes, in both content and organization of resident genes, is rapidly emerging from comparative mapping studies. The frequent occurrence of familial gene clustering, presumably reflecting a history of tandem in situ duplications starting from a single ancestral gene, is also apparent from these analyses. Genes encoding Kruppel-type zinc-finger (ZNF) proteins, including those containing Kruppel-associated box (KRAB) motifs, are particularly prone to such clustered organization. Existing data suggest that genes in KRAB-ZNF gene clusters have diverged in sequence and expression patterns, possibly yielding families of proteins with distinct, yet related, functions. Comparative mapping studies indicate that at least some of the genes within these clusters in mammals were elaborated prior to the divergence of mammalian orders and, subsequently, have been conserved. These data suggest a possible role for these tandem KRAB-ZNF gene families in mammalian evolution.

Severe ethylene glycol ingestion treated without hemodialysis

Fomepizole (4-methylpyrazole, Antizol) is being increasingly used in the treatment of ethylene glycol toxicity in adults. Little experience exists with this drug, however, in the pediatric population. We present a case of ethylene glycol poisoning in a child where use of fomepizole averted intravenous ethanol infusion and hemodialysis, limited the duration of intensive care monitoring, and decreased the overall cost of treatment.

Gamma-hydroxybutyrate, gamma-butyrolactone, and 1,4-butanediol: a case report and review of the literature

GHB, GBL, and 1,4-BD are prevalent drugs of abuse in the United States. Unfortunately, attempts to regulate GHB have been circumvented by clandestine trafficking through the Internet and marketing of "natural" chemical precursors . Despite repeated FDA warnings to the public about their dangers as well as recent federal scheduling of GHB and GBL, they remain accessible as "club drugs" on Internet websites, as natural dietary supplements in health food stores, and as illicit products manufactured at home or in clandestine laboratories. EDs and poison control centers nationwide will undoubtedly continue to manage GHB, GBL, and 1,4-BD toxicities.

Methylenedioxymethamphetamine (MDMA, "Ecstasy")

Ecstasy (MDMA) is an amphetamine derivative of growing popularity. The drug produces a range of toxicities when taken either in standard doses or overdose. In overdose it has major toxicity, producing several different life-threatening manifestations. Hepatotoxicity and hyponatremia are common but poorly understood consequences of MDMA overdose. The drug can produce long-term, if not permanent, neurologic sequelae by destruction of serotonergic neurons. Chronic Ecstasy use can result in psychosis, depression, and suicidal ideation. In the ED setting, it is essential for physicians to recognize and treat appropriately those who present with intoxication from this drug.

Influence of carbohydrate on cytokine and phagocytic responses to 2 h of rowing

PURPOSE

This study examined the influence of carbohydrate (C) versus placebo (P) beverage ingestion on the phagocytic and cytokine responses to normal rowing training by 15 elite female rowers.

METHODS

Athletes received C or P before, during and after, two, 2-h bouts of rowing performed on consecutive days. Blood was collected before and 5-10 min and 1.5 h after rowing. Metabolic measures indicated that training was performed at moderate intensities, with some high-intensity intervals interspersed throughout the sessions.

RESULTS

Concentrations of blood neutrophils and monocytes, phagocytic activity, and plasma IL-1ra were significantly lower postexercise after C versus P ingestion. No differences were observed for oxidative burst activity, IL-6, IL-8, or TNFalpha. Glucose was significantly higher after 2 h of rowing with C ingestion; however, cortisol, growth hormone, epinephrine, norepinephrine, and CRP were not affected by carbohydrate.

CONCLUSIONS

These data indicate that carbohydrate compared with placebo ingestion attenuated the moderate rise in blood neutrophils, monocytes, phagocytosis, and plasma IL-1ra concentrations that followed 2-h bouts of training in elite female rowers. No changes in blood hormone concentrations were found.

Mouse ret finger protein (rfp) proto-oncogene is expressed at specific stages of mouse spermatogenesis

Many proteins involved in the regulation of cell growth and differentiation possess structural motifs that participate in specific molecular interactions. The human rfp (ret finger protein) has a tripartite motif, consisting of two novel zinc fingers (the RING linger and the B box) and a coiled-coil domain, and belongs to the B box zinc finger protein family. Rfp becomes oncogenic when its tripartite motif is recombined with the tyrosine kinase domain from the c-ret proto-oncogene. To further understand the function of rfp during normal development and cellular differentiation, we cloned the mouse rfp cDNA and analyzed its pattern of expression and subcellular distribution. We found that the mouse rfp cDNA shared a 98.4% homology with the human sequence. The gene mapped to human chromosome 6 and mouse chromosome 13 indicating that it was linked to a several other genes encoding proteins that possess common domains. rfp transcripts and protein were ubiquitous in day 10.5-13.5 mouse embryos, however, they were restricted in adult mice, with the highest level of expression in pachytene spermatocytes and round spermatids of differentiating sperm. The rfp protein was detected within cell nuclei as nuclear bodies similar to the PODs (PML oncogenic domains) observed with another B box family member, PML (promyelocytic leukemia protein). These results suggest that rfp may function in the regulation of cell growth and differentiation during mouse embryogenesis and sperm differentiation.

Immune function in female elite rowers and non-athletes

OBJECTIVE

To compare immune function in female rowers and controls in the resting state, and then correlate the results with a two month history of upper respiratory tract infection (URTI).

METHODS

Subjects included 20 elite female rowers located at the ARCO Olympic Training Centre in Chula Vista, California, and 19 non-athletic female controls. These two groups were compared cross sectionally for immune function and infection rates.

RESULTS

Granulocyte/monocyte phagocytosis, oxidative burst activity, and plasma cytokine concentrations (interleukin-6, tumour necrosis factor-alpha, and interleukin-1 receptor antagonist) did not differ significantly between groups. Phytohaemagglutinin induced lymphocyte proliferative response (adjusted whole blood method) was significantly higher (31% and 36% for optimal and suboptimal concentrations respectively) in rowers than in controls. Natural killer cell activity was substantially higher (1.6-fold for total lytic units) in the female rowers than in controls. Two month health logs disclosed 5.2 (1.2) and 3.3 (1.1) days with URTI symptoms for the rowers and controls respectively (p = 0.268). For all 39 subjects combined, and for the 20 rowers separately, none of the immune parameters correlated significantly with number of days with URTI symptoms.

CONCLUSIONS

In this cross sectional comparison of elite female rowers and non-athletes, a group difference was found for natural killer cell activity and phytohaemagglutinin induced proliferative response (whole blood technique), but not other measures of immune function. The number of days with URTI symptoms during the spring season did not differ between groups, and variations in blood measures of immunity were unrelated to URTI.

Visualization of Taylor-Couette and spiral Poiseuille flows using a snapshot FLASH spatial tagging sequence

A new magnetic resonance imaging technique was applied to the Taylor-Couette and spiral Poiseuille (Taylor-Couette with superposed mean axial flux) flows for the first time. The experimental technique is a combination of spatial tagging methods and a snapshot FLASH imaging sequence, which allows the full-field visualization of 2-D slices of the flow field, with image acquisition times approximately half a second. By acquiring images every few seconds, direct visualization of flow patterns can be obtained in the form of cinematography. Tagged images of the Taylor-Couette flow were acquired in both the axial and transverse planes and confirmed previously reported numerical predictions of Taylor cell size. Tagged images of the spiral Poiseuille flows verified that the cells in this flow propagate at a higher velocity than the mean axial flow. In addition, intermittent cell formation was observed as the axial flow was increased.

Saliva immunoglobulins in elite women rowers

Saliva immunoglobulins (sIgA, sIgG, and sIgM) and upper respiratory tract infection (URTI) rates were evaluated in 20 elite female rowers and 19 nonathletes. Also, the influence of carbohydrate versus placebo beverage consumption on saliva immunoglobulin responses to rowing training sessions was measured in 15 rowers and in 5 non-exercising rowers. Saliva samples were collected 1 day before, and 5-10 min and 1.5 h after rowing or rest. Pre-exercise sIgA (but not sIgG or sIgM) concentration was 77% higher in the rowers compared to nonathletes (P < 0.001). Health records kept over 2 months revealed mean 5.2 (SEM 1.2) and 3.3 (SEM 1.1) days with URTI symptoms for the rowers and controls, respectively. For all 39 subjects, and for the 20 rowers separately, no significant correlation was found between URTI symptoms or insulin, cortisol, and growth hormone concentrations and pre-exercise or exercise-related changes in saliva immunoglobulin concentrations or secretion rates. The patterns of change in saliva immunoglobulin concentration and secretion rate did not differ between the carbohydrate and placebo rowing trials, or between exercised and rested athletes. These data indicated an increased sIgA concentration in the female elite rowers compared to the nonathletes, no association between saliva immunoglobulins and URTI, and no effect of a normal 2-hour training session or carbohydrate ingestion on saliva immunoglobulin concentrations or secretion rates.