A mutant of Burkholderia pseudomallei, auxotrophic in the branched chain amino acid biosynthetic pathway, is attenuated and protective in a murine model of melioidosis

Using a transposon mutagenesis approach, we have identified a mutant of Burkholderia pseudomallei that is auxotrophic for branched chain amino acids. The transposon was shown to have interrupted the ilvI gene encoding the large subunit of the acetolactate synthase enzyme. Compared to the wild type, this mutant was significantly attenuated in a murine model of disease. Mice inoculated intraperitoneally with the auxotrophic mutant, 35 days prior to challenge, were protected against a challenge dose of 6,000 median lethal doses of wild-type B. pseudomallei.

Phenylketonuria in adulthood: a collaborative study

During 1967-1983, the Maternal and Child Health Division of the Public Health Services funded a collaborative study of 211 newborn infants identified on newborn screening as having phenylketonuria (PKU). Subsequently, financial support was provided by the National Institute of Child Health and Human Development (NICHD). The infants were treated with a phenylalanine (Phe)-restricted diet to age 6 years and then randomized either to continue the diet or to discontinue dietary treatment altogether. One hundred and twenty-five of the 211 children were then followed until 10 years of age. In 1998, NICHD scheduled a Consensus Development Conference on Phenylketonuria and initiated a study to follow up the participants from the original Collaborative Study to evaluate their present medical, nutritional, psychological, and socioeconomic status. Fourteen of the original clinics (1967-1983) participated in the Follow-up Study effort. Each clinic director was provided with a list of PKU subjects who had completed the original study (1967-1983), and was asked to evaluate as many as possible using a uniform protocol and data collection forms. In a subset of cases, magnetic resonance imaging and spectroscopy (MRI/MRS) were performed to study brain Phe concentrations. The medical evaluations revealed that the subjects who maintained a phenylalanine-restricted diet reported fewer problems than the diet discontinuers, who had an increased rate of eczema, asthma, mental disorders, headache, hyperactivity and hypoactivity. Psychological data showed that lower intellectual and achievement test scores were associated with dietary discontinuation and with higher childhood and adult blood Phe concentrations. Abnormal MRI results were associated with higher brain Phe concentrations. Early dietary discontinuation for subjects with PKU is associated with poorer outcomes not only in intellectual ability, but also in achievement test scores and increased rates of medical and behavioural problems.

Wetland systems for bioregenerative reclamation of wastewater: from closed systems to developing countries

Results are presented from constructed wetland systems designed to treat wastewater in Akumal, Quintana Roo, Mexico, which was developed after prior experience with the Biosphere 2 closed ecological system wetland systems. These systems illustrate the congruity of needs in advanced life support systems and in solving social and environmental problems in developing countries. For sustainable food production for life support, closed ecological systems need to bioregenerate and recycle nutrient-rich wastewater. Developing countries need low-tech ecologically engineered systems that minimize requirements for capital, nonrenewable energy, and technical expertise. Biosphere 2's surface flow wetlands covered 41 m2 and treated the wastewater from eight inhabitants, laboratories, and domestic animals during the 1991-1993 closure experiment. The Mexican wetlands are subsurface flow wetlands using limestone gravel as substrate. Two wetland systems treat sewage from 40 people and cover 131 m2. During the initial year of operation, the wetlands in Akumal reduced BOD 86%, TSS 39%, total P 80%, total N 75%, and coliform bacteria 99.85%. Phosphorus uptake in the limestone gravel was around 6 mg/kg. High biodiversity, with 70 plant species, was maintained in the Akumal constructed wetlands 1.5 years after planting. The Shannon diversity index was 4.7 (base 2). Plant diversity was slightly less than tropical forest ecosystems of the region, but far greater than biodiversity in natural mangrove wetlands.

Potential integration of wetland wastewater treatment with space life support systems

Subsurface-flow constructed wetlands for wastewater treatment and nutrient recycling have a number of advantages in planetary exploration scenarios: they are odorless, relatively low labor and low energy, assist in purification of water and recycling of atmospheric CO2, and can directly grow some food crops. This article presents calculations for integration of wetland wastewater treatment with a prototype ground-based experimental facility ("Mars on Earth") supporting four people showing that an area of 4-6 m2 may be sufficient to accomplish wastewater treatment and recycling. Discharge water from the wetland system can be used as irrigation water for the agricultural crop area, thus ensuring complete reclamation and utilization of nutrients within the bioregenerative life support system. Because the primary requirements for wetland treatment systems are warm temperatures and lighting, such bioregenerative systems can be integrated into space life support systems because heat from the lights may be used for temperature maintenance in the human living environment. Subsurface-flow wetlands can be modified for space habitats to lower space and mass requirements. Many of its construction requirements can eventually be met with use of in situ materials, such as gravel from the Mars surface. Because the technology does not depend on machinery and chemicals, and relies more on natural ecological mechanisms (microbial and plant metabolism), maintenance requirements (e.g., pumps, aerators, and chemicals) are minimized, and systems may have long operating lifetimes. Research needs include suitability of Martian soil and gravel for wetland systems, system sealing and liner options in a Mars base, and determination of wetland water quality efficiency under varying temperature and light regimes.

Thymic activity in late-stage HIV-1 infected individuals receiving highly active antiretroviral therapy: potential effect of steroid therapy

OBJECTIVE

Our objective was to monitor the effect of steroid therapy on the thymic output and function of late-stage HIV-1-infected patients undergoing highly active antiretroviral therapy (HAART).

DESIGN

The indirect measurement of T cells that have recently emigrated from the thymus as a means of quantifying thymic output, and therefore thymic function, was achieved through use of the polymerase chain reaction-based signal joint T cell receptor rearrangement excision circles (sjTREC) assay. Proliferative capacity and interleukin (IL)-2 and IL-4 production by T cells after antigenic, mitogenic and IL-2 stimulation were also analysed.

METHOD

Measurements were made of sjTREC levels in peripheral blood mononuclear cell DNA samples from five HIV-1 infected patients (one on steroid therapy prior to and at the time of sample extraction) receiving HAART. IL-2 and IL-4 production and proliferative capacity were also measured in three patients, including the patient receiving steroids.

RESULT

The sjTREC assay gave an extremely weak result for the patient on steroids but, under the same assay conditions, provided clear, positive readings for the four patients not on steroids. Comparison of the patients' cytokine profiles revealed that IL-2 production was generally low or absent in all three patients tested but that IL-4 production was significantly higher in the patient given steroids. Functional potential as revealed by proliferation assays showed very low or absent cellular proliferation.

CONCLUSION

The thymic contribution to the restoration of T lymphocyte numbers, particularly during the treatment of HIV-1 infection, may become compromised if thymic inhibitory factors such as steroids are used. Furthermore, the use of steroids may also favour the development of a T helper 2 response, which could prove particularly undesirable during HIV-1 infection.

Failure of combination therapy with lamivudine and famciclovir following lamivudine monotherapy for hepatitis B virus infection in patients coinfected with human immunodeficiency virus-1

Individuals coinfected with human immunodeficiency virus 1 (HIV-1) and hepatitis B virus (HBV) often receive treatment with an antiretroviral regimen including lamivudine. Lamivudine monotherapy for HBV may lead to drug-resistant mutations in a significant number of patients. The virological and biochemical responses of 8 patients coinfected with HBV/HIV-1 treated with both lamivudine and famciclovir were studied. Patients exhibiting HBV viral rebound at 1 year were analyzed for the emergence of HBV polymerase mutations. Only 1 patient had no prior exposure to lamivudine. Addition of famciclovir to the treatment regimen resulted in a median fall in HBV DNA level of 0.33 log(10) at 3 months and an overall rise in HBV DNA level of 3 log(10) at 12 months. The only patient in whom durable viral suppression and HBV e antigen seroconversion were noted began receiving lamivudine and famciclovir simultaneously. HBV polymerase gene sequencing identified resistance-associated mutations in 6 of 7 patients with viral rebound. Sequential nucleoside analogue therapy is unlikely to be successful in achieving long-term suppression of HBV replication, and combination therapy should be considered at treatment initiation.

Intrathecal pethidine as sole anaesthetic agent for operative procedures of the lower limb, inguinal area and perineum

Intrathecal pethidine as a sole anaesthetic agent for surgical procedures of the lower limbs, perineum and inguinal areas was investigated and compared with hyperbaric Bupivacaine. A total of 90 patients were studied and randomly divided into groups 1 (bupivacaine) and 2 (pethidine). In group 2, 26 of 46 patients (59%) had their procedures successfully with intrathecal pethidine alone and did not require or request any additional sedation or analgesia. This compared to 24 of 44 patients (52.2%) in the bupivacaine group. Pethidine had a prolonged postoperative analgesia and was more cost-effective. The incidences of side effects were acceptable. (hypotension 13.6%, bradycardia 9.09%, nausea and vomiting 11.4%, and pruritus 15.9%). Pethidine can be used as a sole anaesthetic agent for operative procedures of the lower limbs; side effects are mild and can be treated.

The role of NNRTIs in antiretroviral combination therapy: an introduction

In October 2000 a meeting was convened by DuPont Pharma in Scotland to discuss the role of non-nucleoside reverse transcriptase inhibitors (NNRTIs) in antiretroviral therapy. The Round Table meeting focused on comparisons between efavirenz and nevirapine in clinical studies and clinical practice, and the manuscripts published in this supplement report the most salient points from the presentations and discussions.

Methodological issues using household budget survey expenditure data for individual food availability estimation: Irish experience in the DAFNE pan-European project. DAta Food NEtworking

OBJECTIVE

Irish participation in the EU-supported DAta Food NEtworking (DAFNE) project required compliance with the overall aims and objectives. The Irish Household Budget Survey (HBS) expenditure data had to be transformed into a format compatible with the collaborative effort, by converting them into quantities of foodstuffs available per person per day.

SETTING

The Irish 1987 HBS expenditure data on all commodities for 7705 households in the Republic of Ireland, collected using a 14-day diary kept by all members of the household aged 15 years and over.

DESIGN

Following identification of 188 food items in the HBS dataset, retail prices per unit weight were sought for each food. Adjustment of prices, collected from a number of different sources, was made to those of 1987 using the Consumer Price Index. Simple models were used to estimate household food availability through application of the adjusted retail prices per unit weight to the expenditure data. The household level data were converted to food availability per person per day. An internal validation of quantities estimated using the retail prices was made using the 12 foodstuffs for which the Irish HBS collects expenses and quantities.

RESULTS

The comparison of quantities published by the Irish Central Statistics Office for 12 foodstuffs in the Irish 1987 Household Budget Survey with the quantities estimated using equivalent expenditure data and corresponding retail prices showed agreement, with less than a 10% margin of error for 10 of the foods.

CONCLUSION

In spite some difficulty in converting HBS food expenditure data into food availability per person per day, the DAFNE approach is potentially useful for Irish nutrition surveillance purposes and for facilitating comparisons of the Irish HBS food data with those of other European countries.

The Household Food Consumption and Anthropometric Survey in Poland

OBJECTIVE

To provide an overview of the Household Food Consumption and Anthropometric Survey, undertaken in Poland from September to November 2000.

DESIGN

A sub-sample of households participating in the countrywide, representative household budget survey (HBS) was selected to participate in the Household Food Consumption and Anthropometric Survey. Four thousand two hundred (4200) individuals provided 24-hour recalls that were subsequently evaluated. Body weight and height together with the mid-arm, waist and hip circumferences were measured. Laboratory analyses of contaminants that may be present in selected individual diets will be undertaken.

SETTING

Poland, 2000.

SUBJECTS

Four thousand two hundred individuals from 1362 households participating in the Polish HBS.

RESULTS

Preliminary analyses of height and weight, as well as energy and nutrient intakes, were undertaken in a sub-sample of 484 boys and girls aged 10-15 years. Energy intakes were generally in line with or above the Polish Recommendations.

CONCLUSIONS

Apart from serving as an important information source on individual food consumption and anthropometric status of the Polish population, the data collected through the Household Food Consumption and Anthropometric Survey will allow direct comparisons of food intake estimates, based on 24-hour recalls, with the results of the household budget survey. Such comparisons are expected to improve and refine interpretation of the data derived from both the individual nutrition survey and the household budget survey, and particularly to provide information on the importance of eating out, which is not covered in the Polish HBS.

Biosphere science news roundup. Biosphere 2 completes first two year closure experiment

On September 26, 1993 Biosphere 2 completed it's first two year experiment which included eight "Biospherians." Now that the first experiment is concluded the results can be examined and reported. Future issues of the journal will include more in depth peer reviewed articles on the experiment while this article will give a brief overview. The facility is now between experiments and is undergoing minor upgrades in preparation for the next ten and a half month enclosure scheduled for March 1994. The new crew has been chosen and is "moving in" now. Now that an interval of time has passed since September 26, 1993 and the end of the initial two year closure of Biosphere 2 it is appropriate to take stock of initial accomplishments and problem areas.

Nutrient recycling systems of Biosphere 2. Litterfall, decomposition, and wastewater recycling: results from the 1991-1993 closure experiment

Important aspects of nutrient recycling in Biosphere 2 were plant litterfall/leaf decomposition in the terrestrial biomes and sewage and wastewater processing by a constructed wetland system. During the second year of closure, annual litterfall ranged from 1317 +/- 283 g/m2 in the lowland rainforest to 141 +/- 58 g/m2 in the desert sand dune area. Litterfall patterns followed different seasonal regimes in the biomes. Leaf decomposition averaged 90%/year in Biosphere 2, with the smallest leaf loss in the desert biome. For maintenance of soil fertility in the agricultural area, inedible crop material and domestic animal manure was composted, and human waste products and wastewater from people, labs, and domestic animals was processed in a 41-m2 constructed wetland. The wetland produced 1200 kg of fodder and remaining nutrients were returned to the soils via irrigation water.

Living in space: results from Biosphere 2's initial closure, an early testbed for closed ecological systems on Mars

The following summary of results from the first 2-year closure experiment (September 26, 1991 to September 26, 1993) in Biosphere 2 is excerpted from a chapter written by William Dempster and myself for a book, Strategies for Mars, edited by Carol Stoker and Carter Emmart of NASA Ames Research Center. The book will be published later this year by Krieger Publishers. It brings together a number of the most striking initial results, including food production and nutrition; ecosystem changes; oxygen and carbon dioxide dynamics; and the human role and response to living in a small, recycling life support system. The references cited are useful as a guide to currently available articles in journals. Hopefully, the next year will see a proliferation of papers presenting more data from the first 2 years of Biosphere 2's operation. There was a wealth of data collected during the closure and by teams of researchers who had access to the facility during the 5-month transition period following the departure of the first crew and the commencement of the second closure experiment in March, 1994.

An ecological life support system for fish for 100-day experiments

An aquatic habitat of 1.7 L was designed to support three adult fish (medaka, Oryzias latipes) for 100 days with minimal exchange of water. The Aquatic Habitat consisted of a specimen chamber (800 ml), biofilter chamber and associated tubing (250 ml), and a microbial control chamber (650 ml), filled with water. Fish were fed daily. The water was oxygenated via a hollow fiber oxygenator. The liquid flow rate was 30 ml/min and the air flow as 100 ml/min. Six units were established. Fish mortalities, when they occurred, were often associated with failures of the water flow system and lack of oxygen being supplied from the oxygenator. The bacterial community, from three "Bio-Chem Stars" inoculated from a medaka aquarium, transformed ammonia and prevented toxic conditions from occurring. The bacteria were grazed by protozoa, rotifers, nematodes, oligochaetes, and ostracods in all habitats. In three of six habitats, Daphnia and amphipods had been purposely introduced; their survival was variable. Biofilm and settled particulates accumulated during the experiment and eventually exceeded the weight of the fish. Of six units, two supported the initial fish through the whole experiment, another experienced fish mortalities, but replacement fish survived, and three units did not support fish survival for the 100 days. Our results demonstrated the feasibility of the system, but many improvements are needed such as improved water flow and oxygen monitoring to assure prompt corrective action.

Incidence and risk factors for the development of indinavir-associated renal complications

OBJECTIVES

To describe the incidence and risk factors for the development of indinavir-associated renal complications (IRC), and subsequent clinical outcome.

PATIENTS AND METHODS

This was a retrospective cohort study based on two large HIV centres in London. Eligible patients received indinavir for at least 1 week between 1 December 1995 and 28 February 1999. Development of IRC was ascertained by case-note review. Multivariate logistic regression and Cox Proportional Hazard's model analysis were used to determine independent risk factors for the development of IRC.

RESULTS

781 patients were eligible. Median CD4 count and viral load at indinavir initiation were 117 x 10(6) cells/L and 47 332 copies/mL, respectively. Median indinavir exposure was 53 weeks (IQR: 20-83). Many patients received other potentially nephrotoxic drugs during indinavir treatment: co-trimoxazole (46%), aciclovir (33%) or both (20%). Overall IRC incidence was 7.3% (6.7 per 100 person-years indinavir exposure). Cases presented with loin pain (58%), renal colic (42%) or dysuria (19%). Identified precipitating events (26%) included fluid depletion or altered indinavir regimen. In the majority of cases indinavir therapy was continued and there was no progressive rise in creatinine levels. In the multivariate analysis, for indinavir treatment >74 weeks there was a reduced risk of developing IRC (OR = 0.23, 95% CI 0.09-0.57, P = 0.001). Concomitant aciclovir increased the IRC risk (OR = 1.99, 95% CI 1.14-3.51, P = 0.016). Factors not associated with outcome were age, gender, ethnicity, baseline CD4 count and viral load, concomitant co-trimoxazole, or use of specific antiretrovirals.

CONCLUSION

An overall IRC incidence of 7.3% was identified. Concomitant aciclovir doubled the risk of IRC and we therefore recommend careful monitoring when prescribing aciclovir with indinavir. A precipitating event was identified in 26% of IRC cases, many of which could have been avoided.

Allergic inflammation enhances bacterial sinusitis in mice

BACKGROUND

Although it is not proven, one factor considered important in the development of sinusitis is allergic rhinitis.

OBJECTIVE

The purpose of this study was to determine whether ongoing allergic rhinitis enhances the infection and inflammation associated with Streptococcus pneumoniae acute sinus infection.

METHODS

BALB/c mice were sensitized to ovalbumin by intraperitoneal injection. After infection of the sinuses by S pneumoniae, either with or without concomitant administration of ovalbumin to induce allergic inflammation, mice were killed at various times and their heads were prepared for histologic evaluation of the sinuses.

RESULTS

Mice became allergic to ovalbumin and developed eosinophilia in the sinus and lung cavities in response to ovalbumin administration to each of the respective cavities. In comparison with controls, the mice with ongoing nasal allergic inflammation that were inoculated with S pneumoniae had significantly more bacteria recovered at sacrifice and had significantly more inflammation, as indicated by neutrophil, eosinophil, and mononuclear influx into the sinus mucosa. The percentage of the sinus area occupied by neutrophil clusters was also increased after infection in the allergic mice in comparison with the control mice.

CONCLUSION

Our data demonstrate that mice can be sensitized to ovalbumin and develop a localized allergic reaction in the skin, nose, or lung. An ongoing local allergic response augments bacterial infection in these animals. We also demonstrate that allergic sensitization alone, allergen exposure alone, or an allergic response at a distal site, the lung, does not augment the sinus infection.

Baboon mesenchymal stem cells can be genetically modified to secrete human erythropoietin in vivo

Human mesenchymal stem cells (MSCs) are capable of differentiating into multiple mesenchymal lineages including chondrocytes, osteocytes, adipocytes, and marrow stromal cells. Using a nonhuman primate model, we evaluated nonhuman primate MSCs as targets for gene therapy. Baboon MSCs (bMSCs) cultured from bone marrow aspirates appeared as a homogeneous population of spindle-shaped cells. bMSCs were capable of differentiating into adipocytes and osteocytes in vitro and chondrocytes in vivo. bMSCs were genetically modified with a bicistronic vector encoding the human erythropoietin (hEPO) gene and the green fluorescent protein (GFP) gene. Transduction efficiencies ranged from 72 to 99% after incubation of MSCs with retroviral supernatant. Transduced cells produced from 1.83 x 10(5) to 7.12 x 10(5) mIU of hEPO per 10(6) cells per 24 hr in vitro before implantation. To determine the capacity of bMSCs to express hEPO in vivo, transduced bMSCs were injected intramuscularly in NOD/SCID mice. In a separate experiment, transduced bMSCs were loaded into immunoisolatory devices (IIDs) and surgically implanted into either autologous or allogeneic baboon recipients. Human EPO was detected in the serum of NOD/SCID mice for up to 28 days and in the serum of five baboons for between 9 and 137 days. NOD/SCID mice experienced sharp rises in hematocrit after intramuscular injection of hEPO-transduced bMSCs. The baboon that expressed hEPO for 137 days experienced a statistically significant (p < 0.04) rise in its hematocrit. These data demonstrate that nonhuman primate MSCs can be engineered to deliver a secreted and biologically active gene product. Therefore, human MSCs may be an effective target for future human gene therapy trials.

Parents' Perceptions of Primary Care: measuring parents' experiences of pediatric primary care quality

OBJECTIVE

A measure of pediatric primary care quality that is brief, practical, reliable, and valid would be useful to patients and pediatricians, policymakers, and health system leaders. Parents have a unique perspective from which to report their experiences with their child's primary care, and these reports may be valid indicators of pediatric primary care quality. The research objective was to develop a brief parent report of their children's primary care, the Parent's Perceptions of Primary Care measure (P3C), and to test its reliability and validity as a measure of pediatric primary care quality.

STUDY DESIGN

The P3C was based on the elements of primary care as defined by the Institute of Medicine. Pretesting of domain content and item clarity was accomplished via focus interviews. The P3C was developed in English and translated to Spanish, Vietnamese, and Tagalog. The 23-item P3C yields a total score, as well as subscale scores for continuity, access, contextual knowledge, communication, comprehensiveness, and coordination. The P3C was administered to 3371 parents of children in kindergarten through sixth grades in a large, urban school district.

PRINCIPAL FINDINGS

The percentage of missing values for the overall sample was 1.88%, indicating acceptable feasibility. Range of measurement, assessed via floor and ceiling effects, was moderate to good. Cronbach's coefficient alpha, an indicator of scale internal consistency reliability, was 0.95 for the P3C total scale. Factor analysis supported the subscale structure, and P3C scores were higher for children with health insurance, whose parents completed the survey in English, and who had a regular physician. P3C scores were positively related to parent reports of the child's health-related quality of life.

CONCLUSIONS

The P3C is a practical, reliable, and valid measure of parents' reports of pediatric primary care quality. This brief measure could be used alone, or in conjunction with other measures, to enhance outcomes and evaluate the impact of systems changes on the delivery of the main elements of primary care.

General practitioner participation in the second Australian National Blood Pressure Study (ANBP2)

1. The second Australian National Blood Pressure Study (ANBP2) is an outcome trial of the treatment of hypertension in the elderly conducted entirely in general practices across Australia. Prior to ANBP2, no study of this size and nature had been undertaken in Australian general practice and the response of General Practitioners (GPs) to becoming involved in long-term cardiovascular research was unknown. 2. Academic departments and Divisions of General Practice were approached to support the project. General Practitioners were approached by letter of invitation and contacted by a regional medical coordinator (RMC) either at a face-to-face meeting or by telephone. 3. At the close of recruitment to ANBP2, 1938 GPs from 950 practices had registered as investigators. Sixty-two Divisions of General Practice were approached to support the study in five mainland Australian states with 39 (63%) participating, although participation by state was highly variable (range: 18-100%). Thirty divisional or promotional dinner meetings were held, with 56% (368/658) of those attending registering as investigators. Of the 8098 GPs sent a letter of invitation to participate in the study, 1357 (17%) expressed interest and eventually enrolled as investigators, ranging from 8% in Queensland to 28% in New South Wales. Ninety-six per cent of GPs who had a personal face-to-face contact (696/724) with the RMC registered in the study. 4. The GP recruitment phase of ANBP2 has been successfully completed. Peer-to-peer recruitment was the most successful strategy; however, success varied between states. General Practitioner recruitment to long-term clinical trials appears to be successful with a multifactorial approach focusing on peer-to-peer recruitment.

Steady-state pharmacokinetics and tolerability of modafinil given alone or in combination with methylphenidate in healthy volunteers

The potential for a pharmacokinetic (PK) drug-drug interaction between modafinil and methylphenidate, each at steady state, was investigated in an open-label, randomized, single-period study in 32 healthy male and female volunteers. All subjects received modafinil once daily orally for 28 days (200 mg on Days 1-7 and 400 mg on Days 8-28). On Days 22 to 28, half of the subjects also received 20 mg of methylphenidate orally 8 hours after their modafinil dose. PK profiles of modafinil were obtained on Days 21 and 28 and compared between the two groups. There were no statistically significant differences between the treatment groups in the mean changes in PK parameters for modafinil. Parameters for its metabolites were also similar between the groups, and all treatments were well tolerated. The results indicate that administration of low-dose methylphenidate 8 hours after treatment with modafinil does not appear to alter the steady-state pharmacokinetics of modafinil in healthy volunteers.

Distribution of K103N and/or Y181C HIV-1 mutations by exposure to zidovudine and non-nucleoside reverse transcriptase inhibitors

Our aim was to identify whether zidovudine has a role in the emergence of the K103N resistance mutation in the HIV-1 reverse transcriptase gene on non-nucleoside reverse transcriptase inhibitors (NNRTIs). No difference was found in the exposure to zidovudine or major zidovudine mutations between the resistance patterns K103N-/Y181C+, K103N+/Y181C- and K103N+/ Y181C+, either in group A (patients on nevirapine and previously NNRTI naive) or in group B (on any NNRTI and experience of two or more NNRTIs including nevirapine). Group B patients had the highest prevalence of K103N+/Y181C+. In conclusion, zidovudine seems not to determine the emergence of K103N; however, there appears to be an accumulation of NNRTI resistance mutations with sequential use of NNRTIs.

Receptor activator of NF-kappa B and osteoprotegerin expression by human microvascular endothelial cells, regulation by inflammatory cytokines, and role in human osteoclastogenesis

The receptor activator of NF-kappaB (RANKL) is the essential signal required for full osteoclast (OC) development, activation, and survival. RANKL is highly expressed in areas of trabecular bone remodeling and inflammatory bone loss, is increased on marrow stromal cells or osteoblasts by osteotropic hormones or cytokines, and is neutralized by osteoprotegerin (OPG), a soluble decoy receptor also crucial for preventing arterial calcification. Vascular endothelial cells (VEC) are critically involved in bone development and remodeling and influence OC recruitment, formation, and activity. Although OCs develop and function in close association with bone VEC and sinusoids, signals mediating their interactions are not well known. Here, we show for the first time that human microvascular endothelial cells (HMVEC) express transcripts for both RANKL and OPG; inflammatory cytokines tumor necrosis factor-alpha and interleukin-1alpha elevate RANKL and OPG expression 5-40-fold in HMVEC (with an early OPG peak that declines as RANKL rises), and RANKL protein increases on the surface of tumor necrosis factor-alpha-activated HMVEC. Cytokine-activated HMVEC promoted the formation, fusion, and bone resorption of OCs formed in co-cultures with circulating human monocytic precursors via a RANKL-mediated mechanism fully antagonized by exogenous OPG. Furthermore, paraffin sections of human osteoporotic fractured bone exhibited increased RANKL immunostaining in vivo on VEC located near resorbing OCs in regions undergoing active bone turnover. Therefore, cytokine-activated VEC may contribute to inflammatory-mediated bone loss via regulated production of RANKL and OPG. VEC-derived OPG may also serve as an autocrine signal to inhibit blood vessel calcification.

Translocation t(1;3)(p36.3;q25) is a nonrandom aberration in epithelioid hemangioendothelioma

The cytogenetic findings for two epithelioid hemangioendotheliomas are reported. An identical chromosomal translocation involving chromosomes 1 and 3 [t(1;3)(p36.3;q25)] was detected in both cases of epithelioid hemangioendothelioma, possibly representing a characteristic rearrangement for this histopathologic entity. The presence of clonal karyotypic abnormalities supports a neoplastic origin for the epithelioid variant of hemangioendothelioma. Identification of the 1;3 translocation may be useful diagnostically. Should additional studies confirm these data, this could lead to the identification of the gene(s) central to this neoplastic process.