Biomarkers in Prostate Cancer: A Review

BACKGROUND

Prostate cancer (PC) is the second most common cancer in men worldwide. It's the second leading cause cancer men in death. Prognostic tests based on molecular and biomarker analysis of tumor tissue may improve risk stratification of prostate cancer 2.

MATERIALS AND METHODS

After a search on Pubmed for PC biomarkers, 72 papers responded to the objectives and will be included in the review.

RESULTS

A plethora of biomarkers are predictive for the prognosis of PC and its response to certain therapies, while others, once thought to be indicative of prognosis in PC, were not.

CONCLUSIONS

This study can help in the development of diagnostic and prognostic tests of PC and contribute to the ongoing research into already existing tests.

A metatranscriptomic evaluation of viruses in field-collected bed bugs

Cimex lectularius, known as the common bed bug, is a widespread hematophagous human ectoparasite and urban pest that is not known to be a vector of any human infectious disease agents. However, few studies in the era of molecular biology have profiled the microorganisms harbored by field populations of bed bugs. The objective of this study was to examine the viruses present in a large sampling of common bed bugs and related bat bugs (Cimex pipistrelle). RNA sequencing was undertaken on an international sampling of > 500 field-collected bugs, and multiple workflows were used to assemble contigs and query these against reference nucleotide databases to identify viral genomes. Shuangao bed bug virus 2, an uncharacterized rhabdovirus previously discovered in Cimex hemipterus from China, was found in several bed bug pools from the USA and Europe, as well as in C. pipistrelle, suggesting that this virus is common among bed bug populations. In addition, Shuangao bed bug virus 1 was detected in a bed bug pool from China, and sequences matching Enterobacteria phage P7 were found in all bed bug pools, indicating the ubiquitous presence of phage-derived elements in the genome of the bed bug or its enterobacterial symbiont. However, viral diversity was low in bed bugs in our study, as no other viral genomes were detected with significant coverage. These results provide evidence against frequent virus infection in bed bugs. Nonetheless, our investigation had several important limitations, and additional studies should be conducted to better understand the prevalence and composition of viruses in bed bugs. Most notably, our study largely focused on insects from urban areas in industrialized nations, thus likely missing infrequent virus infections and those that could occur in rural or tropical environments or developing nations.

Exosome-associated lysophosphatidic acid signaling contributes to cancer pain

ABSTRACT

Pain associated with bone cancer remains poorly managed, and chemotherapeutic drugs used to treat cancer usually increase pain. The discovery of dual-acting drugs that reduce cancer and produce analgesia is an optimal approach. The mechanisms underlying bone cancer pain involve interactions between cancer cells and nociceptive neurons. We demonstrated that fibrosarcoma cells express high levels of autotaxin (ATX), the enzyme synthetizing lysophosphatidic acid (LPA). Lysophosphatidic acid increased proliferation of fibrosarcoma cells in vitro. Lysophosphatidic acid is also a pain-signaling molecule, which activates LPA receptors (LPARs) located on nociceptive neurons and satellite cells in dorsal root ganglia. We therefore investigated the contribution of the ATX-LPA-LPAR signaling to pain in a mouse model of bone cancer pain in which fibrosarcoma cells are implanted into and around the calcaneus bone, resulting in tumor growth and hypersensitivity. LPA was elevated in serum of tumor-bearing mice, and blockade of ATX or LPAR reduced tumor-evoked hypersensitivity. Because cancer cell-secreted exosomes contribute to hypersensitivity and ATX is bound to exosomes, we determined the role of exosome-associated ATX-LPA-LPAR signaling in hypersensitivity produced by cancer exosomes. Intraplantar injection of cancer exosomes into naive mice produced hypersensitivity by sensitizing C-fiber nociceptors. Inhibition of ATX or blockade of LPAR attenuated cancer exosome-evoked hypersensitivity in an ATX-LPA-LPAR-dependent manner. Parallel in vitro studies revealed the involvement of ATX-LPA-LPAR signaling in direct sensitization of dorsal root ganglion neurons by cancer exosomes. Thus, our study identified a cancer exosome-mediated pathway, which may represent a therapeutic target for treating tumor growth and pain in patients with bone cancer.

Association Between Combat-Related Traumatic Injury and Skeletal Health: Bone Mineral Density Loss Is Localized and Correlates With Altered Loading in Amputees: the Armed Services Trauma Rehabilitation Outcome (ADVANCE) Study

The association between combat-related traumatic injury (CRTI) and bone health is uncertain. A disproportionate number of lower limb amputees from the Iraq and Afghanistan conflicts are diagnosed with osteopenia/osteoporosis, increasing lifetime risk of fragility fracture and challenging traditional osteoporosis treatment paradigms. The aim of this study is to test the hypotheses that CRTI results in a systemic reduction in bone mineral density (BMD) and that active traumatic lower limb amputees have localized BMD reduction, which is more prominent with higher level amputations. This is a cross-sectional analysis of the first phase of a cohort study comprising 575 male adult UK military personnel with CRTI (UK-Afghanistan War 2003 to 2014; including 153 lower limb amputees) who were frequency-matched to 562 uninjured men by age, service, rank, regiment, deployment period, and role-in-theatre. BMD was assessed using dual-energy X-ray absorptiometry (DXA) scanning of the hips and lumbar spine. Femoral neck BMD was lower in the CRTI than the uninjured group (T-score -0.08 versus -0.42 p = .000). Subgroup analysis revealed this reduction was significant only at the femoral neck of the amputated limb of amputees (p = 0.000), where the reduction was greater for above knee amputees than below knee amputees (p < 0.001). There were no differences in spine BMD or activity levels between amputees and controls. Changes in bone health in CRTI appear to be mechanically driven rather than systemic and are only evident in those with lower limb amputation. This may arise from altered joint and muscle loading creating a reduced mechanical stimulus to the femur resulting in localized unloading osteopenia. This suggests that interventions to stimulate bone may provide an effective management strategy. © 2023 Crown copyright and The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). This article is published with the permission of the Controller of HMSO and the King's Printer for Scotland.

Phospholipase activity of acyloxyacyl hydrolase induces IL-22-producing CD1a-autoreactive T cells in individuals with psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by Th17 responses. Recent evidence has identified Langerhans cells to have a key role in disease pathogenesis, with constitutive high expression of CD1a and capacity to present lipid antigens to T cells. Phospholipase A2 enzymes generate neolipid antigens for recognition by CD1a-reactive T cells; however, the broader enzymatic pathways of CD1a lipid ligand generation have not been thoroughly investigated. In this study, we used immunofluorescence of skin and ELISpot analyses of CD1a-reactive T cells to investigate the role of the lipase acyloxyacyl hydrolase (AOAH) in CD1a ligand generation with relevance to the pathogenesis of psoriasis. We found that the PLA2 activity of rAOAH leads to the activation of circulating CD1a auto-reactive T cells, leading to the production of IFN-γ and IL-22. Circulating AOAH-responsive CD1a-reactive T cells from patients with psoriasis showed elevated IL-22 production. We observed that AOAH is highly expressed in psoriatic lesions compared to healthy skin. Overall, these data present a role for AOAH in generating antigens that activate circulating lipid-specific CD1a-restricted T cells and, thus, contribute to psoriatic inflammation. These findings suggest that inhibition of PLA2 activity of AOAH may have therapeutic potential for individuals with psoriasis.

Hyaluronic Acid-Antibody Fragment Bioconjugates for Extended Ocular Pharmacokinetics

Treatment of ocular diseases associated with neovascularization currently requires frequent intravitreal injections of antivascular endothelial growth factor (anti-VEGF) therapies. Reducing the required frequency of anti-VEGF injections and associated clinical visits may improve patient adherence to the prescribed treatment regimen and improve outcomes. Herein, we explore conjugation of rabbit and fragment antibodies (Fab) to the biopolymer hyaluronic acid (HA) as a half-life modifying strategy, and assess the impact on Fab biophysical properties and vitreal pharmacokinetics. HA-Fab conjugates of three distinct molecular weights and hydrodynamic radii (R_H) were assessed for in vivo pharmacokinetic performance relative to unconjugated Fab after intravitreal injection in rabbits. Covalent conjugation to HA did not significantly alter the thermal stability or secondary or tertiary structure, or diminish the potency of the Fab, thereby preserving its pharmacological properties. Conjugation to HA did significantly slow the in vivo clearance of Fab from the rabbit vitreous in an R_H-dependent manner. Compared to free Fab (observed vitreal half-life of 2.8 days), HA-Fab conjugates cleared with observed half-lives of 7.6, 10.2, and 18.3 days for 40 kDa, 200 kDa, and 600 kDa HA conjugates, respectively. This work elucidates a possible strategy for long-acting delivery of proteins intended for the treatment of chronic posterior ocular diseases.

NMDA receptor modulation of glutamate release in activated neutrophils

Background

Neutrophil depletion improves neurologic outcomes in experimental sepsis/brain injury. We hypothesized that neutrophils may exacerbate neuronal injury through the release of neurotoxic quantities of the neurotransmitter glutamate.

Methods

Real-time glutamate release by primary human neutrophils was determined using enzymatic biosensors. Bacterial and direct protein-kinase C (Phorbol 12-myristate 13-acetate; PMA) activation of neutrophils in human whole blood, isolated neutrophils or human cell lines were compared in the presence/absence of N-Methyl-d-aspartic acid receptor (NMDAR) antagonists. Bacterial and direct activation of neutrophils from wild-type and transgenic murine neutrophils deficient in NMDAR-scaffolding proteins were compared using flow cytometry (phagocytosis, reactive oxygen species (ROS) generation) and real-time respirometry (oxygen consumption).

Findings

Both glutamate and the NMDAR co-agonist d-serine are rapidly released by neutrophils in response to bacterial and PMA-induced activation. Pharmacological NMDAR blockade reduced both the autocrine release of glutamate, d-serine and the respiratory burst by activated primary human neutrophils. A highly specific small-molecule inhibitor ZL006 that limits NMDAR-mediated neuronal injury also reduced ROS by activated neutrophils in a murine model of peritonitis, via uncoupling of the NMDAR GluN2B subunit from its' scaffolding protein, postsynaptic density protein-95 (PSD-95). Genetic ablation of PSD-95 reduced ROS production by activated murine neutrophils. Pharmacological blockade of the NMDAR GluN2B subunit reduced primary human neutrophil activation induced by Pseudomonas fluorescens, a glutamate-secreting Gram-negative bacillus closely related to pathogens that cause hospital-acquired infections.

Interpretation

These data suggest that release of glutamate by activated neutrophils augments ROS production in an autocrine manner via actions on NMDAR expressed by these cells.

Fund

GLA: Academy Medical Sciences/Health Foundation Clinician Scientist. AVG is a Wellcome Trust Senior Research Fellow.

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Neutrophil depletion improves neurologic outcome after injury and infection.

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Pharmacologic NMDAR blockade reduces rapid autocrine release of glutamate/d-serine from activated neutrophils.

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Genetic ablation/small-molecule inhibition of PSD-95 reduces neutrophil ROS.

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NMDAR blockade reduces human neutrophil activated by glutamate-secreting bacteria.

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Activated neutrophils may exacerbate neuronal injury in various forms of critical illness through the release of glutamate.

A Cascade Suzuki–Miyaura/Diels–Alder Protocol: Exploring the Bifunctional Utility of Vinyl Bpin

Cascade reactions are an important strategy in reaction ­design, allowing streamlining of chemical synthesis. Here we report a cascade Suzuki–Miyaura/Diels–Alder reaction, employing vinyl Bpin as a bifunctional reagent in two distinct roles: as an organoboron nucleo­phile for cross-coupling and as a Diels–Alder dienophile. Merging these two reactions enables a rapid and operationally simple synthesis of functionalized carbocycles in good yield. The effect of the organoboron subtype on Diels–Alder regioselectivity was investigated and postsynthetic modifications were carried out on a model substrate. The potential for a complementary Heck/Diels–Alder process was also assessed.

Simple tool for prediction of parotid gland sparing in intensity-modulated radiation therapy

Sparing one or both parotid glands is a key goal when planning head and neck cancer radiation treatment. If the planning target volume (PTV) overlaps one or both parotid glands substantially, it may not be possible to achieve adequate gland sparing. This finding results in physicians revising their PTV contours after an intensity-modulated radiation therapy (IMRT) plan has been run and reduces workflow efficiency. We devised a simple formula for predicting mean parotid gland dose from the overlap of the parotid gland and isotropically expanded PTV contours. We tested the tool using 44 patients from 2 institutions and found agreement between predicted and actual parotid gland doses (mean absolute error = 5.3 Gy). This simple method could increase treatment planning efficiency by improving the chance that the first plan presented to the physician will have optimal parotid gland sparing.

Knowing the risk? NCEPOD 2011: a wake-up call for perioperative practice

The high-risk surgical population comprises a minority of cases but accounts for the majority of postoperative complications and deaths. The most recent National Confidential Enquiry into Patient Outcome and Death review of these patients found highly variable standards of care and made several recommendations for change.

Tight glycaemic control in the critically ill: losing its grip?

Tight glycaemic control in the critically ill is achieved by administering insulin to target a blood sugar concentration of 4.4–6.1 mmol/litre. This is a valid but controversial target: the Surviving Sepsis campaign currently supports a target of <8.3 mmol/litre. Proof of concept was originally demonstrated by Van den Berghe et al (2001) who recruited 1548 ventilated patients, two thirds post-cardiothoracic surgery, and found tight control reduced mortality from 8.0% to 4.6% (P<0.04), compared to conventional control (<11.9 mmol/litre). There was a 5% incidence of hypoglycaemia (blood glucose <2.2 mmol/litre) in the treatment group. However, subsequent studies, including a second by the same group in medical intensive care patients (Van den Berghe et al, 2006), have failed to replicate these impressive results. Some were terminated early owing to increased mortality and hypoglycaemic episodes (Brunkhorst et al, 2008; Wiener et al, 2008). A meta-analysis by Wiener et al (2008) failed to demonstrate any benefit. NICE-SUGAR, the largest single study performed to date, concluded that tight glucose control may increase mortality (Finfer et al, 2009).

Heterosexual anal intercourse among community and clinical settings in Cape Town, South Africa

BACKGROUND

Anal intercourse is an efficient mode of HIV transmission and may play a role in the heterosexual HIV epidemics of southern Africa. However, little information is available on the anal sex practices of heterosexual individuals in South Africa.

PURPOSE

To examine the occurrence of anal intercourse in samples drawn from community and clinic settings.

METHODS

Anonymous surveys collected from convenience samples of 2593 men and 1818 women in two townships and one large city sexually transmitted infection (STI) clinic in Cape Town. Measures included demographics, HIV risk history, substance use and 3-month retrospective sexual behaviour.

RESULTS

A total of 14% (n = 360) men and 10% (n = 172) women reported engaging in anal intercourse in the past 3 months. Men used condoms during 67% and women 50% of anal intercourse occasions. Anal intercourse was associated with younger age, being unmarried, having a history of STI, exchanging sex, using substances, having been tested for HIV and testing HIV positive.

CONCLUSIONS

Anal intercourse is reported relatively less frequently than unprotected vaginal intercourse among heterosexual individuals. The low prevalence of anal intercourse among heterosexual individuals may be offset by its greater efficiency for transmitting HIV. Anal sex should be discussed in heterosexual HIV prevention programming.

Mental health status of Aboriginal and non-Aboriginal Australian prisoners

OBJECTIVE

To compare the mental health of Aboriginal and non-Aboriginal prisoners in New South Wales.

METHODS

The sample consisted of a cross-sectional random sample of sentenced prisoners, and a consecutive sample of reception prisoners. The sample was drawn from 29 correctional centres (27 male, two female) across New South Wales. Overall, 1208 men (226 Aboriginal), and 262 women (51 Aboriginal) participated in the study. Mental illness was detected using the Composite International Diagnostic Interview (CIDI-A) and a number of other screening measures incorporated into the programme.

RESULTS

No differences were detected in mental illness between Aboriginal and non-Aboriginal men, apart from depression, which was lower in the latter group. Aboriginal woman were more likely than non-Aboriginal women to screen positive for symptoms of psychosis in the prior 12 months and have a higher 1 month and 12 month prevalence of affective disorder; they also had higher psychological distress scores. Suicidal thoughts and attempts were the same in both groups.

CONCLUSIONS

These findings confirm that the demand for mental health services in prisons is considerable, and that Aboriginal women are one of the most vulnerable groups. Services and programmes providing an alternative to incarceration are needed, as are culturally sensitive approaches to treatment.

Sexual assault, sexual risks and gender attitudes in a community sample of South African men

Sexual assault against women and HIV infection are both prevalent and related social problems in South Africa. The current study examined hostile attitudes toward women, acceptance of violence against women and masculine ideological beliefs in relation to sexual assault history among men in a Cape Town township in South African. Men (n=435) completed anonymous surveys of sexual assault history, HIV risk history and gender-based attitudes. More than one in five men in this community sample reported that they had either threatened to use force or used force to gain sexual access to a woman in their lifetime. Men with a history of sexual assault were at significantly higher risk for HIV transmission than their non-sexually assaultive counterparts. Men with a history of sexual assault were also more likely to endorse hostile attitudes toward women and were more likely to accept violence against women, although these attitudes and beliefs were prevalent and pervasive across men with and without histories of sexual assault. These findings extend previous research to show that men who have a history of sexual assault also exhibit elevated risks for HIV infection and transmission. Interventions are needed to address hostile attitudes toward women, sexual assault and sexual risks for HIV among South African men.

Development of an HIV risk reduction counselling intervention for use in South African sexually transmitted infection clinics

South Africa urgently needs HIV prevention interventions that can be disseminated for use in clinical and community settings. A brief theory-based HIV risk reduction counselling intervention originally developed in the USA has recently been adapted for use in a South African sexually transmitted infection clinic. The 60-minute risk reduction counselling intervention was grounded in the Information-Motivation-Behavioural Skills (IMB) model of HIV preventive behaviour change, adapted through a series of interdisciplinary collaborative workshops. This paper reports the process of developing and culturally adapting the brief risk reduction counselling intervention. The processes used for adapting the HIV risk reduction counselling for South Africa provides a potential model for conducting technology transfer activities with other HIV prevention interventions. Several lessons learned from this process may help guide future efforts to transfer HIV prevention technologies.

Mental disorder in the New South Wales prisoner population

OBJECTIVES

To determine the prevalence of mental illness among prisoners in New South Wales (NSW), Australia.

METHOD

Mental illness was examined in two NSW prisoner populations: (i) new receptions to the correctional system; and (ii) sentenced prisoners. Reception prisoners were screened at four male centres and one female centre in NSW. The sentenced population was randomly selected from 28 correctional centres across the state. Reception prisoners were screened consecutively whenever possible while the sentenced group was randomly selected as part of the 2001 Inmate Health Survey. We adopted the same instrument, Composite International Diagnostic Interview - Auto (CIDI-A), for diagnosing mental illness as used in the Australian National Survey of Mental Health and Wellbeing.

RESULTS

Overall, 43% of those screened had at least one of the following diagnoses: psychosis, anxiety disorder, or affective disorder. Reception prisoners suffered from mental illness to a greater extent than sentenced prisoners (46%vs. 38%). Women had higher levels of psychiatric morbidity than men (61%vs. 39%). Nine percent (9%) of all prisoners had experienced psychotic symptoms (due to any cause) in the prior 12 months. Twenty percent (20%) of all prisoners had suffered from at least one type of mood disorder and 36% had experienced an anxiety disorder. Posttraumatic stress disorder was the most common disorder, diagnosed in 26% of receptions and 21% of sentenced prisoners.

CONCLUSIONS

These findings confirm that prisoners are a highly mentally disordered group compared with the general community. Given the high prevalence of mental illness identified by this study, it is essential that prison mental health services be adequately resourced to address the demand and, at minimum, ensure that mental health does not deteriorate during incarceration.

Mental disorder in the New South Wales prisoner population

OBJECTIVES

To determine the prevalence of mental illness among prisoners in New South Wales (NSW), Australia.

METHOD

Mental illness was examined in two NSW prisoner populations: (i) new receptions to the correctional system; and (ii) sentenced prisoners. Reception prisoners were screened at four male centres and one female centre in NSW. The sentenced population was randomly selected from 28 correctional centres across the state. Reception prisoners were screened consecutively whenever possible while the sentenced group was randomly selected as part of the 2001 Inmate Health Survey. We adopted the same instrument, Composite International Diagnostic Interview - Auto (CIDI-A), for diagnosing mental illness as used in the Australian National Survey of Mental Health and Wellbeing.

RESULTS

Overall, 43% of those screened had at least one of the following diagnoses: psychosis, anxiety disorder, or affective disorder. Reception prisoners suffered from mental illness to a greater extent than sentenced prisoners (46%vs. 38%). Women had higher levels of psychiatric morbidity than men (61%vs. 39%). Nine percent (9%) of all prisoners had experienced psychotic symptoms (due to any cause) in the prior 12 months. Twenty percent (20%) of all prisoners had suffered from at least one type of mood disorder and 36% had experienced an anxiety disorder. Posttraumatic stress disorder was the most common disorder, diagnosed in 26% of receptions and 21% of sentenced prisoners.

CONCLUSIONS

These findings confirm that prisoners are a highly mentally disordered group compared with the general community. Given the high prevalence of mental illness identified by this study, it is essential that prison mental health services be adequately resourced to address the demand and, at minimum, ensure that mental health does not deteriorate during incarceration.

Single-fiber recording: in vivo and in vitro preparations

This chapter focuses on in vivo and in vitro recording setups of extracellular single-unit recordings of peripheral sensory nerve or dorsal root fibers in rodents. Extracellular single-unit recording methods have been used to obtain a wealth of data about the properties of peripheral nervous system (PNS) and central nervous system (CNS) structures. The rationale for studying the activity of single-unit primary afferent fibers is predicated on the significance of relatively fine variations of fiber responsiveness to mechanical, chemical, and/or thermal stimuli. It involves microdissection of nerve fiber bundles until the electrical activity of a single fiber is isolated. Electrophysiological changes in thresholds and discharge rates of peripheral nociceptors to polymodal stimuli can provide neurophysiological correlation to behavioral hyperalgesia and allodynia as well as to cellular differences observable with immunohistochemistry. This chapter gives an overview about the necessary general and special equipment, details about the different setups and tissue preparations. Additionally, the chapter informs about the procedure of recording from single units, data acquisition and analysis including unit isolation criteria and techniques for spike discrimination techniques and fiber classification. It describes criteria for the classification of nociceptors and identification of cutaneous afferent units.

Comparison of intermittent and continuous palliative chemotherapy for advanced colorectal cancer: a multicentre randomised trial

BACKGROUND

Policies of UK clinicians regarding the duration of chemotherapy for patients with advanced colorectal cancer are not consistent. We aimed to compare effectiveness of continuous and intermittent chemotherapy in such patients.

METHODS

Patients who responded or had stable disease after receiving 12 weeks of the regimens described by de Gramont and Lokich, or raltitrexed chemotherapy, were randomised to either intermittent (a break in chemotherapy, re-starting on the same drug on progression), or continuous chemotherapy until progression.

FINDINGS

354 patients (178 intermittent, 176 continuous) were enrolled from 42 UK centres. At randomisation, 41% of participants had part or complete response; 59% were stable. Only 66 (37%) patients allocated to intermittent treatment restarted as planned, after a median of 130 days. Median time on treatment after restarting was 84 days. Patients in the continuous group remained on treatment for a median of a further 92 days. Similar proportions of patients in both groups received second-line therapy. Patients on intermittent chemotherapy had significantly fewer toxic effects and serious adverse events than those in the continuous group. There was no clear evidence of a difference in overall survival (hazard ratio 0.87 favouring intermittent, 95% CI 0.69-1.09, p=0.23).

INTERPRETATION

Our findings provided no clear evidence of a benefit in continuing therapy indefinitely until disease progression. They showed that it is safe to stop chemotherapy after 12 weeks and re-start the same treatment on progression in patients with chemosensitive advanced colorectal cancer.

A molecular mechanism for genetic warfarin resistance in the rat

Warfarin targets vitamin K 2,3-epoxide reductase (VKOR), the enzyme that produces reduced vitamin K, a required cofactor for g-carboxylation of vitamin K-dependent proteins. To identify VKOR, we used 4'-azido-warfarin-3H-alcohol as an affinity label. When added to a partially purified preparation of VKOR, two proteins were identified by mass spectrometry as calumenin and cytochrome B5. Rat calumenin was cloned and sequenced and the recombinant protein was produced. When added to an in vitro test system, the 47 kDa recombinant protein was found to inhibit VKOR activity and to protect the enzyme from warfarin inhibition. Calumenin was also shown to inhibit the overall activity of the complete vitamin K-dependent g-carboxylation system. The results were repeated in COS-1 cells overexpressing recombinant calumenin. By comparing calumenin mRNA levels in various tissues from normal rats and warfarin-resistant rats, only the livers from resistant rats were different from normal rats by showing increased levels. Partially purified VKOR from resistant and normal rat livers showed no differences in Km-values, specific activity, and sensitivity to warfarin. A novel model for genetic warfarin resistance in the rat is proposed, whereby the concentration of calumenin in liver determines resistance.

Barriers to rotation in methyl formate by dynamic NMR spectroscopy and barriers to 1,3 oxygen-to-oxygen migration in methyl formate and trifluoromethyl formate by ab initio calculations

Free-energy barriers of 9.85 and 11.91 +/- 0.15 kcal/mol at -70.8 degrees C were found by dynamic NMR spectroscopy for the E-to-Z and Z-to-E conversions, respectively, of methyl formate (1) enriched in 13C to 99% for the carbonyl carbon [methyl formate 13C (2)]. These barriers are higher than the literature values reported for -53 degrees C. The free-energy barrier to 1,3 oxygen-to-oxygen migration of the methyl group in methyl formate was determined by ab initio calculations at several levels. The value of 58.7 kcal/mol obtained at the MP2/6-311+G (df,pd) level was compared to a literature barrier for this process (MINDO/3) and to barriers for related compounds. A free-energy barrier of 63.0 kcal/mol for the oxygen - to - oxygen migration of the CF3 group in trifluoromethyl formate (3) was calculated at the MP2/6-31+G level.

H4(D10S170), a gene frequently rearranged in papillary thyroid carcinoma, is fused to the platelet-derived growth factor receptor beta gene in atypical chronic myeloid leukemia with t(5;10)(q33;q22)

The molecular cloning of the t(5;10)(q33;q22) associated with atypical chronic myeloid leukemia (CML) is reported. Fluorescence in situ hybridization (FISH), Southern blot, and reverse transcriptase- polymerase chain reaction analysis demonstrated that the translocation resulted in an H4/platelet-derived growth factor receptor betaR (PDGFbetaR) fusion transcript that incorporated 5' sequences from H4 fused in frame to 3' PDGFbetaR sequences encoding the transmembrane, WW-like, and tyrosine kinase domains. FISH combined with immunophenotype analysis showed that t(5;10)(q33;q22) was present in CD13(+) and CD14(+) cells but was not observed in CD3(+) or CD19(+) cells. H4 has previously been implicated in pathogenesis of papillary thyroid carcinoma as a fusion partner of RET. The H4/RET fusion incorporates 101 amino acids of H4, predicted to encode a leucine zipper dimerization domain, whereas the H4/PDGFbetaR fusion incorporated an additional 267 amino acids of H4. Retroviral transduction of H4/PDGFbetaR, but not a kinase-inactive mutant, conferred factor-independent growth to Ba/F3 cells and caused a T-cell lymphoblastic lymphoma in a murine bone marrow transplantation assay of transformation. Mutational analysis showed that the amino-terminal H4 leucine zipper domain (amino acids 55-93), as well as H4 amino acids 101 to 386, was required for efficient induction of factor-independent growth of Ba/F3 cells. Tryptophan-to-alanine substitutions in the PDGFbetaR WW-like domain at positions 566/593, or tyrosine-to-phenylalanine substitutions at PDGFbetaR positions 579/581 impaired factor-independent growth of Ba/F3 cells. H4/PDGFbetaR is an oncoprotein expressed in t(5;10)(q33;q22) atypical CML and requires dimerization motifs in the H4 moiety, as well as residues implicated in signal transduction by PDGFbetaR, for efficient induction of factor-independent growth of Ba/F3 cells. (Blood. 2001;97:3910-3918)

Palindromic sequence plays a critical role in human foamy virus dimerization

The retroviral RNA genome is dimeric, consisting of two identical strands of RNA linked near their 5' ends by a dimer linkage structure. Previously it was shown that human foamy virus (HFV) RNA transcribed in vitro contained three sites, designated SI, SII, and SIII, which contributed to the dimerization process (O. Erlwein, D. Cain, N. Fischer, A. Rethwilm, and M. O. McClure, Virology 229:251-258, 1997). To characterize these sites further, a series of mutants were designed and tested for their ability to dimerize in vitro. The primer binding site and a G tetrad in SI were dispensable for dimerization. However, a mutant that changed the 3' end of SI migrated slower on nondenaturing gels than wild-type RNA dimers. The sequence composition of the SII palindrome, consisting of 10 nucleotides, proved to be critical for in vitro dimerization, since mutations within this sequence or replacement of the sequence with a different palindrome of equal length impaired in vitro dimerization. The length of the palindrome also seems to play an important role. A moderate extension to 12 nucleotides was tolerated, whereas an extension to 16 nucleotides or more impaired dimerization. When nucleotides flanking the palindrome were mutated in a random fashion, dimerization was unaffected. Changing the SIII sequence also led to decreased dimer formation, confirming its contribution to the dimerization process. Interesting mutants were cloned into the infectious molecular clone of HFV, HSRV-2, and were transfected into BHK-21 cells. Mutations in SII that reduced dimerization in vitro also abolished virus replication. In contrast, constructs containing mutations in SI and SIII replicated to some extent in cell culture after an initial drop in viral replication. Analysis of the SIM1 mutant revealed reversion to the wild type but with the insertion of an additional two nucleotides. Analysis of cell-free virions demonstrated that both replication-competent and replication-defective mutants packaged nucleic acid. Thus, efficient dimerization is a critical step for HFV to generate infectious virus, but HFV RNA dimerization is not a prerequisite for packaging.

Induction of myeloproliferative disease in mice by tyrosine kinase fusion oncogenes does not require granulocyte-macrophage colony-stimulating factor or interleukin-3

Tyrosine kinase fusion oncogenes that occur as a result of chromosomal translocations have been shown to activate proliferative and antiapoptotic pathways in leukemic cells, but the importance of autocrine and paracrine expression of hematopoietic cytokines in leukemia pathogenesis is not understood. Evidence that leukemic transformation may be, at least in part, cytokine dependent includes data from primary human leukemia cells, cell culture experiments, and murine models of leukemia. This report demonstrates that interleukin (IL)-3 plasma levels are elevated in myeloproliferative disease (MPD) caused by the TEL/tyrosine kinase fusions TEL/platelet-derived growth factor beta receptor (PDGFbetaR), TEL/Janus kinase 2 (JAK2), and TEL/neurotrophin-3 receptor (TRKC). Plasma granulocyte-macrophage colony-stimulating factor (GM-CSF) levels were elevated by TEL/PDGFbetaR and TEL/JAK2. However, all of the fusions tested efficiently induced MPD in mice genetically deficient for both GM-CSF and IL-3, demonstrating that these cytokines are not necessary for the development of disease in this model system. Furthermore, in experiments using normal marrow transduced with TEL/PDGFbetaR retrovirus mixed with marrow transduced with an enhanced green fluorescent protein (EGFP) retrovirus, the MPD induced in these mice demonstrated minimal stimulation of normal myelopoiesis by the TEL/PDGFbetaR-expressing cells. In contrast, recipients of mixed GM-CSF-transduced and EGFP-transduced marrow exhibited significant paracrine expansion of EGFP-expressing cells. Collectively, these data demonstrate that, although cytokine levels are elevated in murine bone marrow transplant models of leukemia using tyrosine kinase fusion oncogenes, GM-CSF and IL-3 are not required for myeloproliferation by any of the oncogenes tested.

Differential susceptibility of retroviruses to nucleoside analogues

Retroviruses may cause diseases in their vertebrate hosts. They are distinguished by their common means of replication involving reverse transcription, a process inhibited by nucleoside reverse transcriptase inhibitors (NRTIs) and other compounds used in antiretroviral chemotherapy. Previous work on NRTIs has been limited to their effect on human immunodeficiency virus (HIV) (for review see Ho & Hitchcock, 1989; Weller, 1999) and little information exists regarding the efficacy and therapeutic potential of these drugs against other retroviruses. We have tested all six NRTIs licensed for HIV treatment [didanosine (ddI), zalcitabine (ddC), lamivudine (3TC), stavudine (d4T), zidovudine (AZT) and abacavir (ABC)] against seven retroviruses representative of the traditional subfamilies: Spumavirinae, Lentivirinae and the Oncovirinae. As expected, each drug showed a range of activities against the panel of retroviruses, some drugs inhibiting other viruses at concentrations well below those required for HIV. Overall, AZT was the most active inhibitor (IC50 range, 0.032-1.0 microM), being most active against the Spuma (foamy) viruses. Abacavir was inhibitory for HIV-1, MN strain (HIV-1 MN), amphotrophic murine leukemia virus (MLV-A) and simian foamy virus type 6 (SFV-6). The least effective inhibitor, 3TC (IC50 range, 0.32->100 microM), was most potent against simian retrovirus types 1 and 2 (SRV-1, SRV-2) and HIV-1, but did not inhibit foamy viruses and MLV-A. Additionally, there were differences in the concentration of drug required to inhibit closely related viruses. Taken together, these data suggest that NRTIs have a wide spectrum of antiretroviral activity and the activity of compounds, even against closely related retroviruses, cannot be predicted.

Modulation of the binding of matrix Gla protein (MGP) to bone morphogenetic protein-2 (BMP-2)

Matrix Gla protein (MGP) is an inhibitor of calcification of the arterial wall but the mechanism of inhibition has not been resolved. Since chondrogenesis has been identified in calcified arteries from MPG null mice, we hypothesized that locally produced MGP might inhibit calcification by neutralizing the known effect of bone morphogenetic proteins (BMPs) as promotors of chondrogenesis and bone formation. As the first step to test this hypothesis, we demonstrate that MGP is a binding protein for 125I-BMP-2. Optimal binding is dependent on metals which suggests that the metal binding Gla region in MGP is involved. MGP is shown to undergo a Ca++ induced conformational change despite the presence of the gamma-carboxylase binding site being part of the mature protein sequence. The data propose that MGP matures earlier in the secretory pathway than other vitamin K-dependent proteins. Antibodies were used in an attempt to identify MGP in bovine serum. Conformational specific MGP antibodies were shown to also recognize the Gla region in prothrombin and factor X but did not identify MGP in serum. This finding is supported by electrophoresis data which demonstrate the absence of MGP among Ba-citrate absorbed vitamin K-dependent serum proteins. We conclude that MGP does not exist in normal bovine serum.

Stat5 is essential for the myelo- and lymphoproliferative disease induced by TEL/JAK2

STAT5 is activated in a broad spectrum of human hematologic malignancies. We addressed whether STAT5 activation is necessary for the myelo- and lymphoproliferative disease induced by TEL/JAK2 using a genetic approach. Whereas mice transplanted with bone marrow transduced with retrovirus expressing TEL/JAK2 develop a rapidly fatal myelo- and lymphoproliferative syndrome, reconstitution with bone marrow derived from Stat5ab-deficient mice expressing TEL/JAK2 did not induce disease. Disease induction in the Stat5a/b-deficient background was rescued with a bicistronic retrovirus encoding TEL/JAK2 and Stat5a. Furthermore, myeloproliferative disease was induced by reconstitution with bone marrow cells expressing a constitutively active mutant, Stat5a, or a single Stat5a target, murine oncostatin M (mOSM). These data define a critical role for Stat5a/b and mOSM in the pathogenesis of TEL/JAK2 disease.

Signal transduction and transforming properties of the TEL-TRKC fusions associated with t(12;15)(p13;q25) in congenital fibrosarcoma and acute myelogenous leukemia

The TEL-TRKC fusion is expressed as a consequence of t(12;15)(p13;q25), and is associated with two human cancers: congenital fibrosarcoma and acute myelogenous leukemia (AML). We report that the T/T(F) and T/T(L) fusion variants associated with congenital fibrosarcoma and AML, respectively, are constitutively tyrosine phosphorylated, and confer factor-independent growth to the murine hematopoietic cell line Ba/F3. Retroviral transduction of T/T(L) causes a rapidly fatal myeloproliferative disease in a murine bone marrow transplant (BMT) model, whereas T/T(F) causes a long-latency, pre-B-cell lymphoblastic lymphoma. TEL-TRKC variants are potent activators of the MAP kinase pathway, but neither variant activates Stat5 or other Stat family members. T/T(L), but not T/T(F), induces tyrosine phosphorylation of phospholipase Cgamma (PLCgamma), phosphoinositol-3 kinase and SHC. However, mutation analysis demonstrates that PLCgamma tyrosine phos phorylation by T/T(L) is dispensable for induction of the myeloproliferative phenotype by T/T(L). Collectively, these data demonstrate that the TEL-TRKC fusion variants are oncoproteins that activate the MAP kinase pathway, and do not require activation of either PLCgamma or Stat5 for efficient induction of a myeloproliferative phenotype in the murine BMT model.

Biological variability of serum and urinary N-telopeptides of type I collagen in postmenopausal women

Measurement of N-telopeptides of type I bone collagen (NTX) provides a specific indicator of the current level of bone resorption. The biological intrasubject variability of NTX in urine and serum was studied in 277 postmenopausal women, mean age, 63.6 years +/- 10.2 (+/-SD) years. Second-morning void urine and serum specimens were collected at baseline and for two consecutive days to determine short-term variability (% CV). Long-term variability was determined by comparing NTX results at baseline and two consecutive months. Subjects were instructed to maintain current diet, lifestyle, and medications during the study. The median short-term %CV was 13.1% for urine NTX. This compared with 6.3% for serum NTX. Calculation of long-term %CV showed similar trends, with the %CV for NTX measured in serum (7.5%) lower than when measured in urine (15.6%). Using the least significant change (LSC) calculation, our data show that to be 90% confident that a decrease in NTX after initiation of antiresorptive therapy in an individual patient is not caused by variability alone, a 31 % decrease in urine NTX and a 14% decrease in serum NTX is required. As reported changes in NTX caused by antiresorptive therapy are greater than these calculations; our results support the use of either specimen to measure NTX to monitor the effect of therapy.

Fatal myeloproliferation, induced in mice by TEL/PDGFbetaR expression, depends on PDGFbetaR tyrosines 579/581

The t(5;12)(q33;p13) translocation associated with chronic myelomonocytic leukemia (CMML) generates a TEL/PDGFbetaR fusion gene. Here, we used a murine bone marrow transplant (BMT) assay to test the transforming properties of TEL/PDGFbetaR in vivo. TEL/PDGFbetaR, introduced into whole bone marrow by retroviral transduction, caused a rapidly fatal myeloproliferative disease that closely recapitulated human CMML. TEL/PDGFbetaR transplanted mice developed leukocytosis with Gr-1(+) granulocytes, splenomegaly, evidence of extramedullary hematopoiesis, and bone marrow fibrosis, but no lymphoproliferative disease. We assayed mutant forms of the TEL/PDGFbetaR fusion protein - including 8 tyrosine to phenylalanine substitutions at phosphorylated PDGFbetaR sites to which various SH2 domain-containing signaling intermediates bind - for ability to transform hematopoietic cells. All of the phenylalanine (F-) mutants tested conferred IL-3-independence to a cultured murine hematopoietic cell line, but, in the BMT assay, different F-mutants displayed distinct transforming properties. In transplanted animals, tyrosines 579/581 proved critical for the development of myeloproliferative phenotype. F-mutants with these residues mutated showed no sign of myeloproliferation but instead developed T-cell lymphomas. In summary, TEL/PDGFbetaR is necessary and sufficient to induce a myeloproliferative disease in a murine BMT model, and PDGFbetaR residues Y579/581 are required for this phenotype.

Matrix Gla protein synthesis and gamma-carboxylation in the aortic vessel wall and proliferating vascular smooth muscle cells--a cell system which resembles the system in bone cells

Matrix GLA protein (MGP) is an inhibitor of calcification in the arterial wall and its activity is dependent upon vitamin K-dependent gamma-carboxylation. This modification is carried out by a warfarin sensitive enzyme system that converts specific Glu residues to gamma-carboxyglutamic acid (GLA) residues. Recent studies have demonstrated that the gamma-carboxylation system in the arterial wall, in contrast to that in the liver, is unable to use vitamin K as an antidote to warfarin. By use of immunohistochemistry we demonstrate that MGP is expressed in the arterial wall and immunocytochemistry localized the MGP precursors to the endoplasmic reticulum in vascular smooth muscle cells. Resting smooth vascular muscle cells in the aortic wall and proliferating cells from explants of the aorta have all the enzymes needed for gamma-carboxylation of MGP. However, when compared to the liver system, expression of the enzymes of the gamma-carboxylation system in vascular smooth muscle cells is different. Of particular interest is the finding that the specific activity of the warfarin sensitive enzyme vitamin K epoxide reductase is 3-fold higher in vascular smooth muscle cells than in liver. DT-diaphorase, which catalyses the antidotal pathway for vitamin K reduction in liver, is 100-fold less active in resting vascular smooth muscle cells than in liver. Data obtained from an in vitro gamma-carboxylation system suggest that the antidotal pathway catalyzed by DT-diaphorase in the vessel wall is unable to provide the carboxylase with enough reduced vitamin K to trigger gamma-carboxylation of MGP. This finding provides an explanation to the inability of vitamin K to work as an antidote to warfarin intoxication of the arterial wall. Therefore the vitamin K dependent gamma-carboxylation system in the arterial wall share a common feature with the system in bone cells by being unable to utilize vitamin K as an antidote.

The effect of sound direction on frequency tuning in mouse inferior collicular neurons

This study examined the effect of sound direction on frequency tuning of inferior collicular (IC) neurons of mice under free field stimulation conditions. Fewer than 20% of IC neurons studied were spontaneously active. Discharge patterns can be described as phasic on responders, phasic on-off responders, off responders, choppers and tonic responders. The frequency tuning curves (FTCs) of IC neurons can be described as narrow, intermediate or broad. Although sound direction typically had little effect on most best frequencies (BFs), sharpness of FTCs increased as sound direction changed from contralateral angles to ipsilateral angles. Sound delivered from the upper and lower portions of the frontal auditory space also appeared to produce sharper frequency tuning than from the front. Possible mechanisms underlying this direction dependent frequency tuning are discussed.

Warfarin resistance is associated with a protein component of the vitamin K 2,3-epoxide reductase enzyme complex in rat liver

Warfarin, the most used drug in the world in long-term anticoagulation prophylaxis, targets the vitamin K 2,3-epoxide reductase (VKOR) of the vitamin K cycle in liver. Recently, the enzyme has been identified as a multicomponent lipid-protein enzyme system in the endoplasmic reticulum (ER) membrane (17). As the first step towards understanding genetic resistance to warfarin, we present in this paper data on VKOR from normal and a strain of warfarin resistant laboratory rats maintained in the United States. Metal induced in vitro assembly of the enzyme complex demonstrates that the glutathione-S-transferase (GST) enzyme component of the complex loses its GST activity upon formation of VKOR. Less VKOR activity is measured upon assembly of the complex from warfarin resistant rats. The GST activity measured in warfarin resistant rats, before assembly of the complex, is 10-fold less sensitive to warfarin inhibition than the GST activity measured in normal rats. Microsomal epoxide hydrolase (mEH) is the second component of VKOR. When incubated with the components of VKOR before assembly of the complex, antibodies raised against mEH prevented formation of the enzyme complex. Sequencing of mEH cDNAs from normal and warfarin resistant rats revealed identical sequences. The data suggest that the mutation responsible for genetic warfarin resistance is associated with the GST component of VKOR.

Isolation and characterization of a pufferfish MLL (mixed lineage leukemia)-like gene (fMll) reveals evolutionary conservation in vertebrate genes related to Drosophila trithorax

The MLL gene is interrupted and fused to a number of partner genes as a result of chromosomal translocations in human leukemias. MLL is a very large protein with a unique domain structure and large regions of homology to Drosophila trx. To define the key structural and functional domains of the MLL protein in vertebrates, we have cloned the genomic region encoding an MLL-like gene in the compact model vertebrate genome of Fugu rubripes. While the similarity between the mouse and human MLL proteins is very high, a lower overall similarity is present between the Fugu and mammalian proteins. Several new highly conserved regions were identified in the portion of the protein included in the MLL leukemia-associated fusion proteins. The conserved nature of regions of similarity between vertebrate forms of MLL and the Drosophila TRX proteins, as well as other domains previously suggested to have a functional role in MLL (including the AT hooks and the DNA methyltransferase domain), was also observed. Therefore, strong evolutionary constraints limited sequence divergence within these domains. The information derived from this comparative analysis will form the basis for the functional study of the MLL protein, particularly as it relates to human leukemogenesis.

Sound pressure transformation at the pinna of Mus domesticus

Sound pressure transformation properties at the pinna of laboratory mice. Mus domesticus, were studied by measuring the sound pressure level of continuous tone at a series of frequencies at the tympanic membrane as a function of the position of a sound source under free-field stimulation conditions. Sound pressure transformation functions showed some prominent spectral notches throughout the frequency range of 10-80 kHz tested. When delivered from some angles within the ipsilateral frontal hemisphere, the sound pressure at the tympanic membrane of certain frequencies may be lower than that determined at the corresponding contralateral angles. For each sound frequency tested, there was an angle (the acoustic axis) within the ipsilateral frontal hemisphere from which the delivered sound reached a maximal pressure level at the tympanic membrane. However, sound delivered from the acoustic axis did not always generate a maximal pressure transformation. The isopressure contours determined within 2-5 dB of the maximal pressure were circumscribed, and their contained angular areas were found to decrease with increasing sound frequency. The 2 dB maximal pressure area may appear at more than one angular area for some test frequencies. Removal of the ipsilateral pinna or modification of pinna posture expanded isopressure contours irregularly and split the 2 dB maximal pressure area into several parts.

Assembly of the warfarin-sensitive vitamin K 2,3-epoxide reductase enzyme complex in the endoplasmic reticulum membrane

gamma-Carboxylation of vitamin K-dependent proteins requires a functional vitamin K cycle to produce the active vitamin K cofactor for the gamma-carboxylase which posttranslationally modifies precursors of these proteins to contain gamma-carboxyglutamic acid residues. The warfarin-sensitive enzyme vitamin K epoxide reductase (VKOR) of the cycle reduces vitamin K 2,3-epoxide to the active vitamin K hydroquinone cofactor. Because of the importance of warfarin as an anticoagulant in prophylactic medicine and as a poison in rodent pest control, numerous attempts have been made to understand the molecular mechanism underlying warfarin-sensitive vitamin K 2,3-epoxide reduction. In search for protein components that could be involved in this reaction we designed an in vitro gamma-carboxylation test system where the warfarin-sensitive VKOR produces the cofactor for the gamma-carboxylase. Dissection of this system by chromatographic techniques has identified a member(s) of the glutathione S-transferase gene family as one component of the VKOR enzyme complex in the endoplasmic reticulum membrane. The affinity-purified glutathione S-transferase(s) was sensitive to warfarin but lost its warfarin sensitivity and glutathione S-transferase activity upon association with lipids in the presence of Mn2+ or Ca2+. In the gamma-carboxylation test system, loss of warfarin-sensitive glutathione S-transferase activity coincided with formation of the VKOR enzyme complex. It is proposed that formation of VKOR in the endoplasmic reticulum membrane resembles formation of the lipoxygenase enzyme complex where the glutathione S-transferase-related FLAP protein binds cytosolic lipoxygenase to form a membrane enzyme complex.

Association of antibodies to Chlamydia trachomatis heat-shock protein 60 kD with chronic nongonococcal urethritis

Ninety male patients with acute nongonococcal urethritis (NGU) who presented for follow-up 10-92 days after initiation of treatment were evaluated. A polymerase chain reaction assay and direct fluorescence antibody test were used to detect Chlamydia trachomatis at presentation and during follow-up. Chlamydial heat-shock protein 60 kD (hsp60) serology with an enzyme-linked immunosorbent assay and C. trachomatis serology with a microimmunofluoresence test were undertaken. In 62 (69%) of the men, evidence of chronic urethritis was noted during follow-up. C. trachomatis was detected in only two patients during follow-up. Chlamydial hsp60 antibody was associated with the development of chronic urethritis between 10 and 92 days after treatment began (P < .04), that is, at 10-29 days (P < .02) and at 30-92 days (P < .008). These results are consistent with the theory that immune response to hsp60 is important in the development of this chronic disease. The results also suggest that chronic NGU is not a consequence of continued production of hsp60 by C. trachomatis.

Identification of sites that act together to direct dimerization of human foamy virus RNA in vitro

Retroviral particles contain two molecules of genomic RNA, which are noncovalently linked near their 5' ends in a region called the dimer linkage structure (DLS). By using complementary DNA oligonucleotides and deletion mutants to impair RNA dimerization of the human foamy virus (HFV), three sites, designated SI, SII, and SIII, were found within a 159-nucleotide RNA fragment of HFV that are involved in dimerization in vitro. SI overlaps the primer-binding site; and SII contains the palindromic sequence, UCCCUAGGGA, the disruption of which impairs dimer formation; and SIII extends into the gag gene. The first two sites are highly conserved in the other primate foamy viruses, SFV-1, SFV-3, and SFVcpz, whereas the third appears to be shared only by HFV and SFVcpz. RNA of HFV and SFV-3 could form heterodimers, indicating that both viruses dimerize by similar mechanisms. On testing thermal stability, dimers of the 159-nucleotide fragment dissociated between 40 and 70 degrees, with half of the dimers dissociating at 55 degrees. Since the splice donor site of HFV is located at position 51 of viral RNA, the DLS is part of the genomic RNA exclusively.

A placebo-controlled, double-blind prospective study in healthy female volunteers of dextrin sulphate gel: a novel potential intravaginal virucide

A double-blind, placebo-controlled study was designed to evaluate the safety and tolerability of intravaginal dextrin sulphate (D2S) gel to assess its preliminary suitability as a potential vaginal virucide. Tolerability was assessed by questionnaire and patient interview. Colposcopy with vaginal biopsy was performed to assess the macroscopic and microscopic evidence of inflammation. The potential impact of the gel on normal vaginal flora was examined by quantitative lactobacilli culture with assessment of the ratio of peroxide to nonperoxide-producing organisms. Colposcopy revealed mild erythema in five of 24 subjects receiving active gel and in none of the 12 placebo recipients, but histology in all subjects revealed no evidence of inflammation. No impact on vaginal lactobacilli was found. We conclude that D2S gel is safe and well tolerated intravaginally at the dosing schedule used in this study.

Sound pressure transformation at the pinna of Mus domesticus

Sound pressure transformation properties at the pinna of laboratory mice Mus domesticus were studied by measuring the sound pressure level of a continuous tone at a series of frequencies at the tympanic membrane as a function of the position of a sound source under free-field stimulation conditions. The spectral transformation, the interaural spectral difference, the isopressure contours and the interaural pressure difference contours were plotted. Sound pressure transformation functions showed some prominent spectral notches throughout the frequency range tested (10-80 kHz). However, the notch frequency did not appear to be systematically related to sound direction. The study of interaural pressure difference demonstrated that, when delivered from some angles within the ipsilateral frontal hemisphere, the sound pressure at the tympanic membrane of certain frequencies may be lower than that determined at the corresponding contralateral angles. For each sound frequency tested, there was an angle (the acoustic axis) within the ipsilateral frontal hemisphere from which the delivered sound reached a maximal pressure level at the tympanic membrane. However, the acoustic axis often changed to a new angle after removal of the ipsilateral pinna. In addition, sound delivered from the acoustic axis did not always generate a maximal pressure transformation. The isopressure contours determined within 2-5 dB of the maximal pressure were circumscribed, and their contained angular areas were found to decrease with increasing sound frequency. The 2 dB maximal pressure area may appear at more than one angular area for some test frequencies. Removal of the ipsilateral pinna or modification of pinna posture expanded isopressure contours irregularly and split the 2 dB maximal pressure area into several parts. The sound pressure difference determined between the angles of maximal and minimal sound pressure (the maximal directionality) increased with sound frequency regardless of pinna posture. Acoustic gain of the pinna at the acoustic axis reached 6-12 dB, depending upon sound frequency. However, the pinna gain was not always maximal at the acoustic axis for a given frequency.