TAMBIS--Transparent Access to Multiple Bioinformatics Information Sources

The TAMBIS project aims to provide transparent access to disparate biological databases and analysis tools, enabling users to utilize a wide range of resources with the minimum of effort. A prototype system has been developed that includes a knowledge base of biological terminology (the biological Concept Model), a model of the underlying data sources (the Source Model) and a 'knowledge-driven' user interface. Biological concepts are captured in the knowledge base using a description logic called GRAIL. The Concept Model provides the user with the concepts necessary to construct a wide range of multiple-source queries, and the user interface provides a flexible means of constructing and manipulating those queries. The Source Model provides a description of the underlying sources and mappings between terms used in the sources and terms in the biological Concept Model. The Concept Model and Source Model provide a level of indirection that shields the user from source details, providing a high level of source transparency. Source independent, declarative queries formed from terms in the Concept Model are transformed into a set of source dependent, executable procedures. Query formulation, translation and execution is demonstrated using a working example.

The importance of diagnostic cytogenetics on outcome in AML: analysis of 1,612 patients entered into the MRC AML 10 trial. The Medical Research Council Adult and Children's Leukaemia Working Parties

Cytogenetics is considered one of the most valuable prognostic determinants in acute myeloid leukemia (AML). However, many studies on which this assertion is based were limited by relatively small sample sizes or varying treatment approach, leading to conflicting data regarding the prognostic implications of specific cytogenetic abnormalities. The Medical Research Council (MRC) AML 10 trial, which included children and adults up to 55 years of age, not only affords the opportunity to determine the independent prognostic significance of pretreatment cytogenetics in the context of large patient groups receiving comparable therapy, but also to address their impact on the outcome of subsequent transplantation procedures performed in first complete remission (CR). On the basis of response to induction treatment, relapse risk, and overall survival, three prognostic groups could be defined by cytogenetic abnormalities detected at presentation in comparison with the outcome of patients with normal karyotype. AML associated with t(8;21), t(15;17) or inv(16) predicted a relatively favorable outcome. Whereas in patients lacking these favorable changes, the presence of a complex karyotype, -5, del(5q), -7, or abnormalities of 3q defined a group with relatively poor prognosis. The remaining group of patients including those with 11q23 abnormalities, +8, +21, +22, del(9q), del(7q) or other miscellaneous structural or numerical defects not encompassed by the favorable or adverse risk groups were found to have an intermediate prognosis. The presence of additional cytogenetic abnormalities did not modify the outcome of patients with favorable cytogenetics. Subgroup analysis demonstrated that the three cytogenetically defined prognostic groups retained their predictive value in the context of secondary as well as de novo AML, within the pediatric age group and furthermore were found to be a key determinant of outcome from autologous or allogeneic bone marrow transplantation (BMT) in first CR. This study highlights the importance of diagnostic cytogenetics as an independent prognostic factor in AML, providing the framework for a stratified treatment approach of this disease, which has been adopted in the current MRC AML 12 trial.

Predictors of success within a behavior modification program among male adolescents

48 adolescents placed into a short-term diagnostic group home with a behavior modification program in place were studied. Each subject was administered the Wechsler Intelligence Scale for Children--III and the Screener version of the Wechsler Individual Achievement Test. Assessment data were used to predict the subjects' conduct within the behavioral program as a method of strengthening pretreatment recommendations for planning. Analysis showed that verbal and mathematical skills were significant predictors of the criterion behaviors. These results support the use of cognitive assessment as valid methods of predicting the behavior of teenagers within residential behavior modification programs.

Phase I study of temozolomide in paediatric patients with advanced cancer. United Kingdom Children's Cancer Study Group

A phase I study of temozolomide administered orally once a day, on 5 consecutive days, between 500 and 1200 mg m(-2) per 28-day cycle was performed. Children were stratified according to prior craniospinal irradiation or nitrosourea therapy. Sixteen of 20 patients who had not received prior craniospinal irradiation or nitrosourea therapy were evaluable. Myelosuppression was dose limiting, with Common Toxicity Criteria (CTC) grade 4 thrombocytopenia occurring in one of six patients receiving 1000 mg m(-2) per cycle, and two of four patients treated at 1200 mg m(-2) per cycle. Therefore, the maximum-tolerated dose (MTD) was 1000 mg m(-2) per cycle. The MTD was not defined for children with prior craniospinal irradiation because of poor recruitment. Plasma pharmacokinetic analyses showed temozolomide to be rapidly absorbed and eliminated, with linear increases in peak plasma concentrations and systemic exposure with increasing dose. Responses (CR and PR) were seen in two out of five patients with high-grade astrocytomas, and one patient had stable disease. One of ten patients with diffuse intrinsic brain stem glioma achieved a long-term partial response, and a further two patients had stable disease. Therefore, the dose recommended for phase II studies in patients who have not received prior craniospinal irradiation or nitrosoureas is 1000 mg m(-2) per cycle. Further evaluation in diffuse intrinsic brain stem gliomas and other high-grade astrocytomas is warranted.

Endothelial cells inhibit smooth muscle cell secretion of hyaluronanic acid

OBJECTIVE

Hyaluronanic acid is a glycosaminoglycan that is present soon after arterial injury and that may augment the smooth muscle cell (SMC) response to injury. The effect of bovine endothelial cells (ECs) on bovine SMC hyaluronanic-acid synthesis was assessed with a bilayer coculture model.

METHODS

Hyaluronanic acid was measured in conditioned media by means of radioimmunoassay and in the cell matrix by histochemistry and point hit quantitation. The receptor for hyaluronic acid-mediated motility (RHAMM) expression, which is increased by hyaluronanic acid, was measured by means of immunoblot.

RESULTS

Hyaluronanic acid levels in the conditioned media of SMCs cultured alone (425+/-30 microg/ml/10(6) cells) were greater at 48 hours when compared with SMCs cocultured with ECs (212+/-30 microg/ml/10(6) cells; p < 0.01). Histochemical stain for hyaluronanic acid showed increased hyaluronanic acid in SMCs cultured alone at all time points studied. This finding was confirmed by point hit quantitation at all time points (p < 0.05). Cocultured SMCs had a 50%+/-17% reduction in RHAMM as compared with SMCs cultured alone (p=0.08).

CONCLUSIONS

ECs inhibit SMC hyaluronanic acid synthesis and RHAMM expression. This inhibition may be an important mechanism by which ECs modify the SMC response to injury.

In vitro and in vivo antifungal activity of amphotericin B lipid complex: are phospholipases important?

Amphotericin B lipid complex for injection (ABLC) is a suspension of amphotericin B complexed with the lipids L-alpha-dimyristoylphosphatidylcholine (DMPC) and L-alpha-dimyristoylphosphatidylglycerol. ABLC is less toxic than amphotericin B deoxycholate (AmB-d), while it maintains the antifungal activity of AmB-d. Active amphotericin B can be released from ABLC by exogenously added (snake venom, bacteria, or Candida-derived) phospholipases or by phospholipases derived from activated mammalian vascular tissue (rat arteries). Such extracellular phospholipases are capable of hydrolyzing the major lipid in ABLC. Mutants of C. albicans that were resistant to ABLC but not AmB-d in vitro were deficient in extracellular phospholipase activity, as measured on egg yolk agar or as measured by their ability to hydrolyze DMPC in ABLC. ABLC was nevertheless effective in the treatment of experimental murine infections produced by these mutants. Isolates of Aspergillus species, apparently resistant to ABLC in vitro (but susceptible to AmB-d), were also susceptible to ABLC in vivo. We suggest that routine in vitro susceptibility tests with ABLC itself as the test material may not accurately predict the in vivo activity of ABLC and that the enhanced therapeutic index of ABLC relative to that of AmB-d in vivo may be due, in part, to the selective release of active amphotericin B from the complex at sites of fungal infection through the action of fungal or host cell-derived phospholipases.

Immunolymphoscintigraphy in breast cancer: evaluation using 131I-labeled monoclonal antibody B72.3

Noninvasive axillary lymph node staging was investigated using [131I]murine monoclonal antibody B72.3 in 16 patients with breast cancer scheduled for axillary dissection. [131I]B72.3 was injected into ipsilateral finger webs or around the breast biopsy. Scintigraphy to 72 h and gamma-counting/immunohistochemistry of nodes were performed. Specific antibody uptake (%ID/g) and the ratio of specific:nonspecific antibody uptake were not significantly different in tumor-positive versus tumor-negative nodes, suggesting that [131I]B72.3 is unsuitable to discriminate axillary node tumor involvement.

Progression of human immunodeficiency virus disease is associated with increasing disruptions within the CD4+ T cell receptor repertoire

The immunodeficiency caused by human immunodeficiency virus (HIV) infection may be related to loss of diversity in the T cell receptor (TCR) repertoire. A cross-sectional study of the CD4 TCR repertoire was done for patients at various stages of HIV infection. Semiquantitative polymerase chain reaction was used to study the relative usage of the variable chain beta (BV) subfamilies and the size distributions of transcripts (CDR3 size analysis) within these subfamilies. The relative usage of the TCRBV subfamilies of patients and controls was not significantly different. The proportion of subfamilies with abnormal CDR3 size patterns was higher in the HIV-infected patients (25%, 95% confidence interval [CI], 17%-33%) than in the controls (7.2%, 95% CI, 2.3%-12.1%; P < .001), with a significant negative correlation between the number of CD4 cells and the percentage of abnormal TCRBV subfamilies. These results indicate that progressive loss of CD4 T cells is accompanied by increasing disruptions within the T cell receptor repertoire.

Prevalence of HIV, syphilis and genital chlamydial infection among women in north-west Ethiopia

The prevalence of sexually transmitted diseases (STD) among women visiting antenatal (ANC) and gynaecological clinics in Gondar, north-west Ethiopia, was investigated. Between April and August 1995, 728 women consented to enter the study. Prevalence rates were 5.9% (41/693) for chlamydial antigen in cervix, 18.8% (113/600) for syphilis (Treponema pallidum haemagglutination assay [TPHA]) and 25.3% (150/593) for HIV. Active syphilis (RPR)+, TPHA+ was detected in 74% (44/597). HIV infection rate was higher among women with higher age of first marriage and low gravidity. It was significantly associated with young age, urban residence, and presence of genital ulcer (odds ratio [OR] = 6.3), and lymphadenopathy (OR = 2.8) on examination. Women seropositive for syphilis had married at an earlier age, were significantly older and had changed husbands. Low gravidity and age < 30 were independently significant risk factors for cervical chlamydial antigen positivity which was predominantly asymptomatic. Significant association was observed between HIV infection and syphilis (OR = 2.6). Active syphilis was associated with chlamydial (OR = 3.4) and HIV infection (OR = 4.1). The rate of 23.4% and 15.1% of HIV seropositivity among ANC attenders and rural women respectively is an indicator of the rapid progression of the HIV epidemic in the area.

Porcine cerebroside sulfate activator (saposin B) secondary structure: CD, FTIR, and NMR studies

Cerebroside sulfate activator protein (CSAct or saposin B) is one of a group of heat stable, low-molecular-weight proteins that appear to share a common structural motif. These have been referred to as saposin-like proteins and are thought to share a multiple amphipathic helical barrel structure with a conserved pattern of disulfide linkages. Porcine kidney CSAct was prepared in high purity and consisted of three major glycosylated subforms. The protein was studied by physical-chemical methods and evaluated by various methods for structural prediction. All suggest that CSAct has high amounts of alpha-helical conformation and little if any beta-sheet. Circular dichroism (CD) studies indicate 45-50% helical conformation depending on buffer and temperature. There was only a moderate loss in helical content with increasing temperature and no indication of thermal denaturation. Fourier transform infrared spectroscopy (FTIR) measurements on deuterium hydrated self-films also indicated a predominantly helical structure. Helical axis orientation was investigated by both oriented CD and FTIR dichroism, which suggested that the helical axes were roughly parallel and oriented along the axis of the surface on which the self-films had been deposited. One-dimensional nuclear magnetic resonance spectra showed large chemical shift dispersion, indicating a defined tertiary structure with little variation between 6 and 85 degrees C. NOESY spectra failed to show the strong NOE cross peaks expected for a highly helical conformation. This may indicate short-term conformational flexibility within the helices or molecular aggregation at the high protein concentrations employed. These observations are consistent with the 3-4-helix bundle motif suggested for saposin-like proteins by various predictive algorithms.

Enhancement of the in vivo circulation lifetime of L-alpha-distearoylphosphatidylcholine liposomes: importance of liposomal aggregation versus complement opsonization

Incorporation of N-(omega-carboxy)acylamido-phosphatidylethanolamines (-PEs) into large unilamellar vesicles (LUVs) of L-alpha-distearoylphosphatidylcholine (DSPC) was found to dramatically increase the in vivo liposomal circulation lifetime in rats, reaching a maximal effect at 10 mol.% of the total phospholipid. Neither pure DSPC liposomes nor those with the longest circulating derivative, N-glutaryl-dipalmitoylphosphatidylethanolamine (-DPPE), were found to significantly bind complement from serum. Therefore, the relatively short circulation time of pure DSPC liposomes did not appear to be related to greater complement opsonization leading to uptake by the reticuloendothelial system. However, N-(omega-carboxy)acylamido-PEs were particularly efficient inhibitors of a limited aggregation detected for pure DSPC liposomes. The aggregation tendency of DSPC liposomes incorporating various structural analogs of N-glutaryl-DPPE correlated inversely with the circulation lifetimes. Therefore, it is concluded that such PE derivatives enhance the circulation time by preventing liposomal aggregation and avoiding a poorly understood mechanism of clearance that is dependent on size but is independent of complement opsonization. At high concentrations of N-glutaryl-DPPE (above 10 mol.%), the liposomes exhibited strong complement opsonization and were cleared from circulation rapidly, as were other highly negatively charged liposomes. These data demonstrate that both the lack of opsonization and the lack of a tendency to aggregate are required for long circulation. Liposomal disaggregation via N-(omega-carboxy)acylamido-PEs yields a new class of large unilamellar DSPC liposomes with circulation lifetimes that are comparable to those of sterically stabilized liposomes.

The internal structure of the Eating Disorder Inventory

The Eating Disorder Inventory (EDI; Garner, Olmsted, & Polivy, 1983) is used as a screening instrument for identifying potential anorexia nervosa and bulimia nervosa. It comprises eight subscales: Bulimia, Drive for Thinness, Body Dissatisfaction, Maturity Fears, Introceptive Awareness, Perfectionism, Interpersonal Distrust, and Ineffectiveness. We examined the internal structure of the EDI using a principle components factor analysis, for a sample of women with no known eating disorder. The results of the factor analyses showed differences between the extracted factors and Garner et al.'s subscales. Seven factors were extracted, accounting for 60.8% of the variance. The first factor accounted for 33.5% of the variance. The analysis indicated that items factored along positive-negative and factual-emotional lines. We conclude that at present there is not enough evidence to support the efficacy of the subscale structure with women who are not known to have eating disorders.

Relationship of serotype, leukotoxin gene type and lysogeny in Actinobacillus actinomycetemcomitans to periodontal disease status

Actinobacillus actinomycetemcomitans has been associated with different forms of periodontitis, particularly with localized juvenile periodontitis (LJP). The bacterium possesses several virulence factors which have been shown to interact with the host immune system. Among these factors, leukotoxin, surface antigens (serotype) and bacteriophages have been suggested directly or indirectly to influence the course of infection. However, few studies have been able to show associations between these factors and periodontal disease, alone or in combination. Thus, the purpose of the present study was to investigate possible correlations between periodontal disease status and selected virulence factors (serotype, presence of bacteriophages, and the presence of a 530 bp deletion in the promoter region of the leukotoxin gene). 36 subjects took part in the study. Serotype c was the most frequently found serotype among periodontally affected subjects, although serotypes a and b were also present. 27 out of 36 strains harbored bacteriophages, and there was strong evidence that some of the bacteriophages were different from the previously characterized phi Aa phage. A. actinomycetemcomitans containing the F-fragment phage were more frequently associated with periodontal disease. Five strains, all serotype b, 3 from LJP patients and 2 from healthy subjects, showed a 530-bp deletion in the promoter region of the leukotoxin gene.

Recurrent branch retinal infarcts in association with migraine

Migraine has been blamed for a variety of temporary and permanent visual complications. We describe the case of a young woman with migraine who suffered recurrent episodes of retinal infarction, one of which occurred during an attack of migraine. The infarctions resulted from occlusions of branches of the central retinal artery. Extensive laboratory and radiological investigations failed to establish a nonmigrainous etiology. In some individuals, migraine may cause or promote branch retinal vaso-occlusion and infarction.

Surveying Public Health Nurses' Continuing Education Needs: Collaboration of Practice and Academia

In the last twenty years, entry level requirements for public health nursing have shifted to less and less educational preparation. Many agencies hire registered nurses with associate degree or diploma preparation who have no experience. The shift in entry level requirements has challenged public health nursing administrators and educators to examine continuing education needs to meet knowledge deficits among public health nurses. The study reported here presents findings from a national survey of 56 state and territorial health departments. The results clarify the continuing education needs and issues related to the educational gaps of public health nurses of the 1990s.

Field immobilization of muskrats (Ondatra zibethicus) for minor surgical procedures

A combination of ketamine hydrochloride and xylazine hydrochloride at doses of 50 mg/kg and 5 mg/kg, respectively, was used to immobilize 48 muskrats (Ondatra zibethicus) from October 1993 to November 1994 in Tennessee (USA). Mean (+/-SD) time for induction was 2.97 +/- 1.1 min. After a mean (+/-SD) duration of 27.2 +/- 3.5 min intramuscular yohimbine hydrochloride at a dose of 0.125 mg/kg was administered. Mean (+/-SD) recovery time was 48.1 +/- 21.6 min. All anesthetic inductions were smooth and sufficient depth of anesthesia was achieved to allow surgical collection of adipose tissue. Recovery times were more variable than expected. There was a significant (P < or = 0.05) drop in heart rate, respiratory rate, and body temperature during anesthesia. One animal died during recovery.

Access to care: a home visitation program that links public health nurses, physicians, mothers, and babies

The purpose of the project here was to develop and test interventions designed to improve access to care and health outcomes for Medicaid-eligible infants during their first 6 months of life. The goal of the intervention was to overcome personal and structural barriers to care by combining the efforts of county health departments and private physicians' offices in 2 counties in North Carolina. The project combined home visits and an office intervention.

Noonan syndrome: coagulation and clinical aspects

The study aims were to review the clinical features of a group of patients with Noonan syndrome and to further elucidate their bleeding tendency. Eighteen patients (12M, 6F) aged 2.6-13.3 years underwent a clinical assessment, a questionnaire of their bleeding tendency and laboratory coagulation studies. Nine had cyanotic spells or breathing difficulties after birth; 11 had poor feeding or weight gain. Increased bruising or bleeding was reported in 12 (67%), four of whom had bleeding from the oral cavity. Excessive bleeding was not reported from operative procedures in other sites. Partial thromboplastin time was prolonged in 10 (56%) associated with low levels of clotting factors, particularly XI and XII. Bleeding times were normal; one had marginal thrombocytopenia. Coagulation results did not correlate with bruising history and may not predict bleeding risk. Care is required when Noonan syndrome patients undergo surgery, particularly of the oropharynx, with immediate availability of suitable blood products.

Pharmacokinetics and pharmacodynamics of subcutaneous interleukin-2 in HIV-infected patients

STUDY OBJECTIVES

To assess the pharmacokinetics and pharmacodynamics of subcutaneously administered interleukin-2 (IL-2) in patients infected with the human immunodeficiency virus (HIV).

DESIGN

Open, dose-escalating phase I clinical trial.

SETTING

Government research hospital.

PATIENTS

Eighteen patients infected with HIV.

INTERVENTIONS

Recombinant IL-2 at dosages of 12, 15, or 18 MIU/day was administered subcutaneously once or twice/day for 5 consecutive days every 2 months. A total of 28 cycles of therapy were included in the analysis.

MEASUREMENTS AND MAIN RESULTS

Concentrations of IL-2 in serum were determined by a commercial enzyme-linked immunosorbent assay. Interleukin-2 was well absorbed, with peak concentrations from 21.9-112.9 IU/ml. Absorption was slow, with mean (+/- SD) time to maximum of 4.4 +/- 1.8 hours and a lag time of 26.9 +/- 13.7 minutes. Elimination half-life was 3.3 +/- 0.9 hours. The concentrations had wide variability both within and among patients. Levels of tumor necrosis factor-alpha were increased. Maximum body temperature and systemic side effects were associated with peak serum levels.

CONCLUSION

Interleukin-2 is well absorbed after subcutaneous injection in HIV-infected patients, and that route of administration is an alternative to intravenous infusions.