Clustering of related individuals in a population of the Australian lizard, Egernia frerei

Stable social aggregations are rarely recorded in lizards, but have now been reported from several species in the Australian scincid genus Egernia. Most of those examples come from species using rock crevice refuges that are relatively easy to observe. But for many other Egernia species that occupy different habitats and are more secretive, it is hard to gather the observational data needed to deduce their social structure. Therefore, we used genotypes at six polymorphic microsatellite DNA loci of 229 individuals of Egernia frerei, trapped in 22 sampling sites over 3500 ha of eucalypt forest on Fraser Island, Australia. Each sampling site contained 15 trap locations in a 100 x 50 m grid. We estimated relatedness among pairs of individuals and found that relatedness was higher within than between sites. Relatedness of females within sites was higher than relatedness of males, and was higher than relatedness between males and females. Within sites we found that juvenile lizards were highly related to other juveniles and to adults trapped at the same location, or at adjacent locations, but relatedness decreased with increasing trap separation. We interpreted the results as suggesting high natal philopatry among juvenile lizards and adult females. This result is consistent with stable family group structure previously reported in rock dwelling Egernia species, and suggests that social behaviour in this genus is not habitat driven.

Mechanism-based inhibition of CYP activities in rat liver by fluoxetine and structurally similar alkylamines

1. The inhibition of cytochrome P450 (CYP)-mediated substrate oxidations by alkylamine-based drugs was investigated in rat hepatic microsomes. The effects of pre-incubation of the drugs with NADPH-fortified microsomes on inhibition potency was evaluated in relation to the formation of metabolite intermediate (MI) complexes with CYP in vitro. 2. The selective serotonin-reuptake inhibitor fluoxetine (FLU) emerged as a potent and preferential inhibitor of CYP2C11 in rat liver microsomes. After FLU biotransformation in NADPH-supplemented microsomes, IC50 values of 2 and 1 microM were determined against CYP2C11-dependent testosterone 2alpha- and 16alpha-hydroxylation; in the absence of pre-incubation, the corresponding IC50 values were 47 and 39 microM. MI complexation of CYP appeared to contribute significantly to inhibition by FLU, as evidenced by the 21% decrease in apparent microsomal CYP content produced by 50 microM FLU in the presence of NADPH. 3. The secondary amines nisoxetine (NIS), and especially, desipramine (DES) and nortriptyline (NOR), also inhibited CYP2C11 and generated MI complexes with microsomal CYP. In contrast, with the exception of SKF-525-A, tertiary alkylamines (10 compounds) inhibited specific CYP activities but did not form MI complexes. Pre-incubation of these agents with NADPH-supplemented microsomes did not enhance inhibition of CYP activities, thus suggesting that formation of inhibitory metabolites was minimal for these compounds. 4. These findings implicate drug-mediated MI complexation of CYPs in the inhibition of hepatic biotransformation processes by secondary alkylamines. In contrast, tertiary amines did not generate significant quantities of CYP-MI complexes under the test conditions. Despite their diffusion from the CYP active site, inhibition produced by tertiary amines and stable metabolites of other drugs may be significant. However, such inhibition would be of shorter duration than that from MI complexation, which involves quasi-covalent binding to the haem and prevention of oxygen activation.

On a roll: the process of initiation and cessation of problem gambling among adolescents

As gambling becomes more accessible and acceptable in society, problems associated with gambling and gaming have begun to affect ever increasing numbers of adolescents. Although restricted from most forms of gambling by law, many adolescents are finding a path into problem gambling. Some are becoming compulsive gamblers early in their gambling career, facing a future filled with consequences and problems. Understanding the pathway or process by which these adolescents become engaged in gambling behavior and how they can extricate themselves from this addictive behavior can enhance the efficiency and effectiveness of our interventions. This article offers a perspective on the initiation and cessation of compulsive gambling using the basic elements of the process of intentional behavior change outlined in the Stages of Change from the Transtheoretical Model. The process of initiation of a problematic behavior is similar to the process of modification or cessation of a problematic behavior in terms of these stages of change. With adolescents it is important to distinguish between the process of initiation, which has implications for prevention of gambling problems, and the process of cessation, which often necessitates the assistance of treatment. Creating interventions that parallel the process of change offers the potential for personalizing and potentiating efforts to reduce the prevalence and consequences associated with compulsive or pathological and problem gambling. Application of this model to gambling behavior offers a heuristic that is intriguing and requires substantiation through rigorous research.

Cognitive and psychosocial functioning of pediatric hematopoietic stem cell transplant patients: a prospective longitudinal study

A prospective longitudinal study of cognitive and psychosocial functioning in pediatric hematopoietic stem cell transplant (HSCT) patients was conducted on three occasions: pre-HSCT, 1 year post-HSCT, and 2 years post-HSCT. In contrast to the previous hypothesis that cognitive declines would occur as a result of HSCT treatment, it was hypothesized that (1) global cognitive functioning (IQ scores), as well as specific areas would remain stable over time; (2) pre-transplant functioning would be predictive of later functioning; and (3) age would be negatively related to cognitive functioning. Based on previous research it was further hypothesized: that (4) while declines in psychosocial functioning might be seen at 1 year, functioning would improve by 2 years. 153 children and adolescents were evaluated pre-HSCT and at 1 year, with 2 year data available for 74 children. Longitudinal analyses of Wechsler IQ data were completed on 100 children (longitudinal exact test) and 52 children (repeated measures analysis of variance. Results of cognitive assessment indicated (1) stability of IQ scores over time; and (2) that the strongest predictor was pre-HSCT cognitive functioning. Psychosocial assessment results indicated: (1) a low prevalence of behavioral and social problems; (2) stability in functioning over time; (3) pre-HSCT functioning strongly predictive of later functioning.

Relationship between change in balance and self-reported handicap after vestibular rehabilitation therapy

BACKGROUND AND PURPOSE

Dizziness and balance problems are two commonly reported symptoms of vestibular system disease, with subsequent alterations in lifestyle and reports of physical, functional and emotional handicap. Vestibular rehabilitation therapy (VRT) was developed to improve the functional status of patients with vestibular dysfunction. The aim of the present study was to investigate the relationship between change in balance performance and change in self-rated handicap after a four-week home exercise programme in 16 subjects with chronic vestibular disease.

METHOD

Before and after the treatment intervention, balance was tested by use of a Smart Balance Master (SBM) system (Neurocom International, Clackamas, OR, USA) and self-rated handicap was measured by use of the Dizziness Handicap Inventory (DHI).

RESULTS

Significant improvement was observed in both the SBM (p < 0.001) and DHI (p = 0.003) scores over the testing period. A moderately strong negative correlation existed between change in SBM and DHI scores (Spearman's r = -0.6). Further analysis using the DHI subscales indicated, however, that the emotional component showed no significant change over time, and a poor correlation with change in balance scores (Spearman's r = -0.39).

CONCLUSIONS

These results indicate that a home-based exercise programme can significantly improve balance abilities in people with chronic vestibular dysfunction, but that outcomes may be enhanced by addressing the emotional issues associated with their disability.

Autologous stem cell transplantation for paediatric-onset polyarteritis nodosa: changes in autoimmune phenotype in the context of reduced diversity of the T- and B-cell repertoires, and evidence for reversion from the CD45RO(+) to RA(+) phenotype

We have studied immune reconstitution in a patient with paediatric-onset polyarteritis nodosa treated with high-dose immunosuppressive agents followed by stem cell rescue. The patient developed several new autoimmune phenomena over the 18 months after immunosuppression and stem cell rescue. Flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR) heteroduplex and isotype-specific RT-PCR analysis of immunoglobulin expression showed that the T- and B-cell repertoires were highly restricted in the first few months after treatment. The dominant T-cell clones seen after reconstitution were persistently expanded, were different from those which could be demonstrated before autologous stem cell transplantation, and were in the CD8(+) population. Our data also show that 12 months after treatment these expanded T-cell clones were within the CD45RA(+) population, suggesting that reversion from the CD45RO(+) to the CD45RA(+) phenotype had occurred in vivo.

Neurocognitive outcome in brain metastases patients treated with accelerated-fractionation vs. accelerated-hyperfractionated radiotherapy: an analysis from Radiation Therapy Oncology Group Study 91-04

PURPOSE

To evaluate neurocognitive outcome as measured by the Mini-Mental Status Examination (MMSE) among patients with unresectable brain metastases randomly assigned to accelerated fractionation (AF) vs. accelerated hyperfractionated (AH) whole-brain radiation therapy (WBRT).

METHODS AND MATERIALS

The Radiation Therapy Oncology Group (RTOG) accrued 445 patients with unresectable brain metastases to a Phase III comparison of AH (1.6 Gy b.i.d. to 54.4 Gy) vs. AF (3 Gy q.d. to 30 Gy). All had a KPS of >or= 70 and a neurologic function status of 0-2. Three hundred fifty-nine patients had MMSEs performed and were eligible for this analysis. Changes in the MMSE were analyzed according to criteria previously defined in the literature.

RESULTS

The median survival was 4.5 months for both arms. The average change in MMSE at 2 and 3 months was a drop of 1.4 and 1.1, respectively, in the AF arm as compared to a drop of 0.7 and 1.3, respectively, in the AH arm (p = NS). Overall, 91 patients at 2 months and 23 patients at 3 months had both follow-up MMSE and computed tomography/magnetic resonance imaging documentation of the status of their brain metastases. When an analysis was performed taking into account control of brain metastases, a significant effect on MMSE was observed with time and associated proportional increase in uncontrolled brain metastases. At 2 months, the average change in MMSE score was a drop of 0.6 for those whose brain metastases were radiologically controlled as compared to a drop of 1.9 for those with uncontrolled brain metastases (p = 0.47). At 3 months, the average change in MMSE score was a drop of 0.5 for those whose brain metastases were radiologically controlled as compared to a drop of 6.3 for those with uncontrolled brain metastases (p = 0.02).

CONCLUSION

Use of AH as compared to AF-WBRT was not associated with a significant difference in neurocognitive function as measured by MMSE in this patient population with unresectable brain metastases and limited survival. However, control of brain metastases had a significant impact on MMSE.

Phase II radiation therapy oncology group trial of weekly paclitaxel and conventional external beam radiation therapy for supratentorial glioblastoma multiforme

PURPOSE

Fractionated external beam radiotherapy (EBRT) +/- carmustine (BCNU) is the standard of care for patients with glioblastoma multiforme (GBM), but survival results remain poor. Preclinical studies indicate synergy between RT and paclitaxel (TAX) in astrocytoma cell lines. Phase I studies in GBM have demonstrated a maximum tolerated dose for TAX of 225 mg/m(2)/3 h/week x 6, during EBRT, with no exacerbation of typical RT-induced toxicities. The Radiation Therapy Oncology Group (RTOG) therefore mounted a Phase II study to determine the feasibility and efficacy of conventional EBRT and concurrent weekly TAX at its MTD.

PATIENTS AND METHODS

Sixty-two patients with histologic diagnosis of GBM were enrolled from 8/16/96 through 3/21/97 in a multi-institutional Phase II trial of EBRT and TAX 225 mg/m(2)/3 h (1-3 h before EBRT), administered the first treatment day of each RT week. Total EBRT dose was 60 Gy (200 cGy/fraction), 5 days per week. A smaller treatment field, to include gross disease plus a margin only, was used after 46 Gy.

RESULTS

Sixty-one patients (98%) were evaluable. Median age was 55 years (range, 28-78). Seventy-four percent were > or = 50 years. Recursive partitioning analysis (RPA) Classes III, IV, V, VI included 10 (17%), 21 (34%), 25 (41%), and 5 (8%) patients, respectively. Gross total resection was performed in only 16%. There was no Grade 3 or 4 neutropenia or thrombocytopenia. Hypersensitivity reactions precluding further use of TAX occurred in 4 patients. There were 2 instances of late neurotoxicity (4% Grade 3 or 4). Ninety-one percent of patients received treatment per protocol. Seventy-seven percent completed prescribed treatment (6 weeks). Of 35 patients with measurable disease, CR/PR was observed in 23%, MR in 17%, and SD in 43%. Seventeen percent demonstrated progression at first follow-up. Median potential follow-up time is 20 months. Median survival is 9.7 months, with median survivals for RPA classes III, IV, V, and VI of 16.3, 10.2, 9.5, 2.5 months, respectively. Ten patients remain alive.

CONCLUSION

Concurrent full-dose EBRT and weekly high-dose TAX is feasible in the majority of GBM patients. Acute toxicity is acceptable; myelosuppression and peripheral sensory neuropathy are surprisingly modest, despite considerably higher overall dose intensity, compared to that achievable in other disease sites. Median survival by RPA class without prolonged adjuvant therapy is comparable to RTOG controls treated with standard EBRT and BCNU (1 year of BCNU).

Neuregulin signaling regulates neural precursor growth and the generation of oligodendrocytes in vitro

Neuregulin 1 (Nrg-1) isoforms have been shown to influence the emergence and growth of oligodendrocytes, the CNS myelin-forming cells. We have investigated how Nrg-1 signaling of ErbB receptors specifically controls the early stages of oligodendrocyte generation from multipotential neural precursors (NPs). We show here that embryonic striatal NPs express multiple Nrg-1 transcripts and proteins as well as their specific receptors, ErbB2 and ErbB4, but not ErbB3. The major isoform synthesized by striatal NPs is a transmembrane type III isoform called cysteine-rich domain Nrg-1. To examine the biological effect of Nrg-1, we added soluble ErbB3 (sErbB3) to growing neurospheres. This inhibitor of Nrg-1 bioactivity decreased mitosis of NPs and increased their apoptosis, resulting in a significant reduction in neurosphere size and number. When NPs were induced to migrate and differentiate by adhesion of neurospheres to the substratum, the level of type III isoforms detected by RT-PCR and Western blot decreased in parallel with a reduction in Nrg-1 fluorescence intensity in differentiating astrocytes, neurons, and oligodendrocytes. Pretreatment of growing neurospheres with sErbB3 induced a threefold increase in the proportion of oligodendrocytes generated from NPs migrating out of the neurosphere. This effect was not observed with an unrelated soluble receptor. Addition of sErbB3 during NP growth and differentiation enhanced oligodendrocyte maturation as shown by expression of galactocerebroside and myelin basic protein. We propose that both type III Nrg-1 signaling and soluble ErbB receptors modulate oligodendrocyte development from NPs.

The outbreak of West Nile virus infection in the New York City area in 1999

BACKGROUND

In late August 1999, an unusual cluster of cases of meningoencephalitis associated with muscle weakness was reported to the New York City Department of Health. The initial epidemiologic and environmental investigations suggested an arboviral cause.

METHODS

Active surveillance was implemented to identify patients hospitalized with viral encephalitis and meningitis. Cerebrospinal fluid, serum, and tissue specimens from patients with suspected cases underwent serologic and viral testing for evidence of arboviral infection.

RESULTS

Outbreak surveillance identified 59 patients who were hospitalized with West Nile virus infection in the New York City area during August and September of 1999. The median age of these patients was 71 years (range, 5 to 95). The overall attack rate of clinical West Nile virus infection was at least 6.5 cases per million population, and it increased sharply with age. Most of the patients (63 percent) had clinical signs of encephalitis; seven patients died (12 percent). Muscle weakness was documented in 27 percent of the patients and flaccid paralysis in 10 percent; in all of the latter, nerve conduction studies indicated an axonal polyneuropathy in 14 percent. An age of 75 years or older was an independent risk factor for death (relative risk adjusted for the presence or absence of diabetes mellitus, 8.5; 95 percent confidence interval, 1.2 to 59.1), as was the presence of diabetes mellitus (age-adjusted relative risk, 5.1; 95 percent confidence interval, 1.5 to 17.3).

CONCLUSIONS

This outbreak of West Nile meningoencephalitis in the New York City metropolitan area represents the first time this virus has been detected in the Western Hemisphere. Given the subsequent rapid spread of the virus, physicians along the eastern seaboard of the United States should consider West Nile virus infection in the differential diagnosis of encephalitis and viral meningitis during the summer months, especially in older patients and in those with muscle weakness.

Updated results of the phase III Radiation Therapy Oncology Group (RTOG) trial 85-31 evaluating the potential benefit of androgen suppression following standard radiation therapy for unfavorable prognosis carcinoma of the prostate

PURPOSE

To determine the potential advantage of androgen ablation following standard external-beam radiation therapy in patients with locally advanced (clinical or pathologic T3; clinical or pathologic node positive) carcinoma of the prostate.

METHODS AND MATERIALS

In 1987 the RTOG initiated a Phase III trial of long-term adjuvant goserelin in definitively irradiated patients with carcinoma of the prostate. A total of 977 patients were accrued to the study of which 945 remain analyzable: 477 on the adjuvant hormone arm (Arm I); and 468 on the radiation only arm (Arm II) with hormones initiated at relapse. The initial results were reported in the Journal of Clinical Oncology in 1997.

RESULTS

With a median follow up of 5.6 years for all patients and 6.0 years for living patients local failure at 8 years was 23% for Arm I and 37% for Arm II (p < 0.0001). Distant metastasis was likewise favorably impacted with the immediate use of hormonal manipulation with a distant metastasis rate in Arm I of 27% and 37% in Arm II (p < 0.0001). Disease-free survival (NED survival) and NED survival with PSA of 1.5 ng/mL (bNED) or less were both statistically significant in favor of the immediate hormone arm (both p < 0.0001). Cause-specific failure was not statistically different with a cause-specific failure of 16% for Arm I and 21% in Arm II (p = 0.23). Overall survival was likewise not statistically different between two arms, with a 49% overall survival at 8 years in Arm I and 47% in Arm II (p = 0.36). Subset analysis of centrally reviewed Gleason 8-10 patients who did not undergo prostatectomy showed that for patients receiving radiation therapy plus adjuvant hormones there was a statistically significant improvement in both absolute (p = 0.036) and cause-specific survival (p = 0.019).

CONCLUSIONS

Use of long-term adjuvant androgen deprivation in addition to definitive radiation therapy results in a highly significant improvement in regards to local control, freedom from distant metastasis, and biochemical free survival in unfavorable prognosis patients with carcinoma of the prostate.

FKBP binding characteristics of cardiac microsomes from diverse vertebrates

FK506 binding protein (FKBP) is a cytosolic receptor for the immunosuppressive drug FK-506. The common isoform, FKBP12, was found to be associated with the calcium release channel (ryanodine receptor 1) of different species of vertebrate skeletal muscle, whereas 12.6, a novel FKBP isoform was found to be associated with canine cardiac ryanodine receptor (ryanodine receptor 2). Until recently, canine cardiac sarcoplasmic reticulum was considered to be the prototype for studying heart RyR2 and its interactions with FKBP. In this study, cardiac microsomes were isolated from diverse vertebrates: human, rabbit, rat, mice, dog, chicken, frog, and fish and were analyzed for their ability to bind or exchange with FKBP isoforms 12 and 12.6. Our studies indicate that RyR2 from seven out of the eight animals contain both FKBP12 and 12.6. Dog is the exception. It can now be concluded that the association of FKBP isoforms with RyR2 is widely conserved in the hearts of different species of vertebrates.

Unusual presentation of thoracic Pneumocystis carinii infection in a patient with acquired immunodeficiency syndrome

Pleura-based masses and hilar adenopathy were seen on a chest radiograph of a patient with acquired immunodeficiency syndrome who had a history of Pneumocystis carinii infection. The differential diagnosis of such a presentation is discussed in light of atypical and extrapulmonary manifestations of P. carinii infection in a patient receiving prophylaxis with dapsone.

Evaluating a telemedicine system to assist in the management of dermatology referrals

BACKGROUND

Teledermatology systems fall into two categories: live video or store-and-forward. In the former, video-conferencing equipment is used to connect a patient with a remote consultant. This method has been evaluated as an aid to dermatology, but it is expensive both in terms of capital and running costs. Video consultations are generally longer than conventional ones and harder to schedule. Some authors have considered store-and-forward as an alternative to live video: instead of a consultation, specialists could make a rapid inspection of a transmitted still image.

OBJECTIVES

A study was conducted to evaluate the role of telemedicine in the dermatology outpatients department of a district general hospital (Whittington Hospital NHS Trust, London, U.K.).

METHODS

One hundred and ninety-four patients were seen by one of two consultant dermatologists. A nurse used a video camera to store digital images of each patient's problem and compiled a history from the GP's referral letter. The images were reviewed 13 months later by both dermatologists; they recorded a provisional diagnosis and an assessment of how urgent an appointment would have been made given the information provided by the system. A third consultant graded the level of agreement between the telemedicine diagnoses and the face-to-face consultations.

RESULTS

High levels of agreement were found between the diagnoses of the dermatologists using the system to inspect images and those of the dermatologist who saw the patients (77%). Consultants using the system recommended fewer urgent appointments (32% compared with 64%) and felt that in 31% of cases the patient did not need to be seen. In 15% of these cases (5% of the total), however, their diagnosis differed significantly from that of the consultant who saw the patient. Had the system been in use, 14% of patients conventionally assigned a non-urgent appointment would have been seen urgently.

CONCLUSIONS

The images allowed a reasonably accurate diagnosis. The software was not reliable (six cases could not be viewed), or easy to use (it took approximately an hour to view 20 cases) but an improved version could be used in triaging outpatient appointments.

Electrodermal activity and temperament in preschool children

This study had two objectives: To examine poorly understood patterns of young children's electrodermal reactivity and to test the hypothesis that this reactivity reflects individual differences in the behavioral inhibition system (BIS). We recorded skin conductance responses (SCRs) from 92 4-year-old children during a laboratory session that encompassed physiological and psychological stimuli. Physiological stimuli (breaths), moderately loud to loud sounds (expected and unexpected) and, to a lesser extent, stimuli with psychological significance elicited clear SCRs. Induction of psychological conflict and exposure to emotional film clips for the most part did not elicit increases in skin conductance (SC). Children's temperament dimensions of fearfulness and effortful (or inhibitory) control--two components of the BIS--were assessed using robust observational batteries at age 2 and 4 years. The theoretically expected correlations between overall SC lability (reflecting SC levels) and both dimensions of temperament were significant, albeit modest and limited to the contemporaneous measures at age 4.

Social and gender variation in the prevalence, presentation and general practitioner provisional diagnosis of chest pain

OBJECTIVES

To describe the prevalence of Rose angina and non-exertional chest pain in men and women in socioeconomically contrasting areas; to describe the proportions of men and women who present with the symptom of chest pain and who receive a provisional general practitioner diagnosis of coronary heart disease; to assess the effects of gender and deprivation.

DESIGN

Two random general population samples in socially contrasting areas were surveyed using the Rose angina questionnaire: the case notes of people identified with chest pain were reviewed.

SETTING

Glasgow conurbation.

PARTICIPANTS

1107 men and women, aged 45-64, with chest pain.

OUTCOME MEASURES

Prevalence of Rose angina and non-exertional chest pain; the proportions who had presented with chest pain and received a general practitioner's provisional diagnosis of coronary heart disease.

RESULTS

There was no difference between social groups in the prevalence of all chest pain but a greater proportion of those in deprived groups had Rose angina and a greater proportion of these had the more severe grade. The proportion of people who had presented with chest pain was higher among socioeconomically deprived groups but there was no difference in the proportions receiving a general practitioner provisional diagnosis of coronary heart disease. Men were more likely to present with chest pain than women and were more likely to receive a provisional general practitioner diagnosis of coronary heart disease.

CONCLUSIONS

No evidence was found of social differences in patient presentation or general practitioner diagnosis that might explain reported variations in uptake of cardiology services. In contrast, gender variation may originate in part from differences in patient presentation and general practitioner diagnosis. Further investigation of socioeconomic variations in uptake of cardiology services should focus later in the care pathway, on general practitioner referral patterns and clinical decisions taken in secondary care.

Validation of the RTOG recursive partitioning analysis (RPA) classification for brain metastases

PURPOSE

The Radiation Therapy Oncology Group (RTOG) previously developed three prognostic classes for brain metastases using recursive partitioning analysis (RPA) of a large database. These classes were based on Karnofsky performance status (KPS), primary tumor status, presence of extracranial system metastases, and age. An analysis of RTOG 91-04, a randomized study comparing two dose-fractionation schemes with a comparison to the established RTOG database, was considered important to validate the RPA classes.

METHODS AND MATERIALS

A total of 445 patients were randomized on RTOG 91-04, a Phase III study of accelerated hyperfractionation versus accelerated fractionation. No difference was observed between the two treatment arms with respect to survival. Four hundred thirty-two patients were included in this analysis. The majority of the patients were under age 65, had KPS 70-80, primary tumor controlled, and brain-only metastases. The initial RPA had three classes, but only patients in RPA Classes I and II were eligible for RTOG 91-04.

RESULTS

For RPA Class I, the median survival time was 6. 2 months and 7.1 months for 91-04 and the database, respectively. The 1-year survival was 29% for 91-04 versus 32% for the database. There was no significant difference in the two survival distributions (p = 0.72). For RPA Class II, the median survival time was 3.8 months for 91-04 versus 4.2 months for the database. The 1-year survival was 12% and 16% for 91-04 and the database, respectively (p = 0.22).

CONCLUSION

This analysis indicates that the RPA classes are valid and reliable for historical comparisons. Both the RTOG and other clinical trial organizers should currently utilize this RPA classification as a stratification factor for clinical trials.

Continuous postoperative catheter irrigation is not necessary for the treatment of suppurative flexor tenosynovitis

The records of 75 patients admitted with pyogenic flexor tenosynovitis at two academic centers were reviewed. The functional outcomes of patients who received intraoperative irrigation only (n = 20) and those that had both intraoperative irrigation and continuous postoperative irrigation (n = 55) were compared. There were no statistically significant differences between the outcomes in the two groups.

Bronchopulmonary and mediastinal leishmaniasis: an unusual clinical presentation of Leishmania donovani infection

We describe a case of unusual leishmaniasis in a Sudanese man with a history of progressively enlarging granulomatous mediastinal lymphadenopathy, worsening hemoptysis, and an intense mucosal granulomatous inflammatory response in the large bronchi. Leishmania donovani DNA was detected in bronchial biopsies by polymerase chain reaction. This is a novel description of human leishmanial infection in an immunocompetent patient involving this anatomical site. The patient's condition improved clinically, spirometrically, and radiologically after a course of treatment with amphotericin B. The cell-mediated immune response was analyzed before, during, and after successful antileishmanial chemotherapy.

Pharmacokinetics, pharmacodynamics, allometry, and dose selection of rPSGL-Ig for phase I trial

rPSGL-Ig is a recombinant, soluble, and chimeric form of P-selectin glycoprotein ligand-1, which is developed as an antagonist to P-selectin. Allometric and pharmacokinetic/pharmacodynamic modeling was used to select doses for human clinical trials. Pharmacokinetic parameters of rPSGL-Ig such as clearance (CL), volume of distribution (Vc), and t(1/2) across animal species are well described by power functions with body weight as an independent variable. The power functions for CL, Vc, and t(1/2) were CL = 0.37. W(0.93) ml/h (r(2) = 0.94), Vc = 45.0.W(1.064) ml (r(2) = 0.988), and t(1/2) = 190.W(0.159) h (r(2) = 0.75), respectively. These functions provide a means to predict pharmacokinetics of rPSGL-Ig in humans. For a 70-kg human, the values of CL, Vc, and t(1/2) are predicted to be 19.9 ml/h, 4138 ml, and 15.5 days, respectively. The predicted pharmacokinetics in humans is used in conjunction with pharmacological data to estimate appropriate doses for clinical trials. The doses that may provide potential effects in humans range from 0.13 to 4.7 mg/kg. The predicted doses produce concentrations above those that are associated with efficacy in animal disease models and, maintain concentrations above the EC(50) of in vitro binding between rPSGL-Ig and stimulated human platelets. Hence, rPSGL-Ig in clinical trials may provide therapeutic activities for P-selectin-mediated diseases.

Biochemical and compositional analyses of recombinant lecithin:cholesterol acyltransferase (LCAT) obtained from a hepatic source

Lecithin:cholesterol acyltransferase (LCAT) is an important plasma glycoprotein which plays a central role in lipid metabolism. This protein is responsible for generation of cholesteryl esters in plasma and it has been proposed to play a pivotal role in the reverse cholesterol transport pathway. Structural and functional studies of LCAT have employed various expression systems for production of recombinant LCAT (rLCAT). However, recent studies have shown some differences in the oligosaccharide structure and composition of rLCAT. In this study, we have generated a new hepatic based expression system using McArdle-RH7777 (Mc-7777) cells to produce a recombinant protein most similar to human plasma LCAT. The expressed glycoprotein was compared to the LCAT expressed in previously characterized baby hamster kidney (BHK) cells. Both proteins were compared on the basis of their carbohydrate structure and composition as well as their functional properties. Although the functional properties of both glycoproteins were similar, the carbohydrate structure was significantly different. While BHK-LCAT contained bi-, tri-, and tetraantennary structures, Mc-7777 LCAT presented only biantennary oligosaccharide structures. The difference in glycosylation pattern of rLCAT from Mc-7777 and BHK cells underlines the importance of appropriate expression system, both in vivo and in vitro.

Why are growth factors important in oligodendrocyte physiology?

Recent studies in chicken, rodents and transgenic mice have provided new insight on the nature of factors essential to oligodendrocyte development. Here we first review how sonic hedgehog (shh) graded signalling induces emergence of oligodendrocytes in the embryonic spinal cord from birds to man. We then discuss the way in which thyroid hormone successively signals different thyroid receptors to control fate determination, growth and differentiation in the oligodendrocyte lineage. Platelet-derived growth factor (PDGF) is a potent regulator of oligodendrocyte progenitor (OP) migration and proliferation, while insulin-like growth factor 1 (IGF-1) acts both on neurons and myelin-forming cells to promote myelination. The balance between OP proliferation and differentiation appears to be controlled by different sets of growth factors locally synthesized in the central nervous system (CNS) as well as glutamate. In experimental models of multiple sclerosis (MS), the neuregulin isoform glial growth factor 2, IGF-1 and some neurotrophins can promote remyelination after an episode of inflammatory demyelination. A future challenge is to determine how to induce multipotential neural precursors to generate migratory OP and enhance the remyelination process in the adult CNS.

For the love of the children: the coming out process for lesbian and gay parents and stepparents

This research investigated the coming out decision and process for 23 lesbian and gay custodial stepfamilies. We argue that lesbian and gay stepfamilies represent a unique type of family, distinct from heterosexual stepfamilies and from lesbian and gay families who have children within the context of a lesbian or gay relationship. The coming out process is one developmental challenge that distinguishes lesbian and gay stepfamilies from these other types. Through interviews with both lesbian and gay parents and stepparents we explored their coming out process to significant others: the children, families of origin and ex-spouses. We discuss those factors influencing the decision and the consequences that developed in light of these decisions. Findings show that the coming out process for lesbian and gay co-parents is a flexible and familial one, primarily influenced by and centered around the needs of the children.

Evaluation of serum-lipid-related cardiovascular risk factors in Alzheimer's disease

There is now sufficient evidence to suggest that cardiovascular pathology and altered lipid metabolism contribute to the development of late-onset Alzheimer's disease (AD). In the present study, 24 AD patients and 15 controls were assessed for cardiovascular risk based on serum lipid and lipid oxidation parameters. The AD patients appeared to have a more favorable cardiovascular risk profile than the controls based on high-density lipoprotein cholesterol (HDL-C) values. The levels of thiobarbituric-acid-reactive substances and the activity of the enzyme paraoxonase (PON) following copper oxidation indicate that female patients may have better protection against serum and perhaps tissue oxidants than males with AD. While the higher HDL-C values indicate lower cardiovascular risk, additional data on oxidized lipid parameters suggest a lower level of protection against serum oxidants in male AD probands. CopyrightCopyright 1999S.KargerAG,Basel

The core antigen of hepatitis B virus as a carrier for immunogenic peptides

The core antigen of hepatitis B virus (HBcAg) made in Escherichia coli yields particles that closely resemble the viral nucleocapsid. Extensive modifications can be made to the primary structure of HBcAg without impairing particle assembly. This enables other peptide sequences, including very long sequences, to be added, substituted, or inserted into the nucleocapsid subunit while retaining the ability to form highly immunogenic particles. These also retain the T cell epitopes of HBcAg and constitute powerful delivery systems for a diverse range of immunogenic epitopes and have significant potential for development of multicomponent vaccines.

Two distinct segments of the hepatitis B virus surface antigen contribute synergistically to its association with the viral core particles

The long surface antigen polypeptide (L-HBsAg) of hepatitis B virus (HBV) is believed to mediate contact between the virus envelope and nucleocapsid protein (HBcAg). The N and C termini of L-HBsAg were shortened progressively in order to define the minimum contiguous sequence of amino acids that contains the residues necessary for association with HBcAg. The resulting mutants were expressed in rabbit reticulocyte lysates and their interaction with HBcAg was examined with an immunoprecipitation assay and an equilibrium binding assay in solution to give relative dissociation constants. Binding of HBcAg particles by L-HBsAg displayed two widely differing dissociation constants, indicating two distinct binding sites between the molecules. The two distinct sites, one located between residues 24 and 191 and the other between residues 191 and 322 of L-HBsAg, contribute synergistically to high-affinity binding to HBcAg, but disruption of either of these segments resulted in a much weaker interaction showing only one dissociation constant. Inhibition of the interaction by peptides that bind to the tips of the nucleocapsid spikes differentiated contacts in HBcAg for the two binding domains in L-HBsAg and implied that the amino-terminal binding domain contacts the tips of the HBcAg spikes. Analysis of specific single amino acid mutants of L-HBsAg showed that Arg92 played an important role in the interaction.

Peptides that block hepatitis B virus assembly: analysis by cryomicroscopy, mutagenesis and transfection

Peptides selected to bind to hepatitis B virus (HBV) core protein block interaction with the long viral surface antigen (L-HBsAg) in vitro. High resolution electron cryomicroscopy showed that one such peptide binds at the tips of the spikes of the core protein shell. The peptides contain two basic residues; changing either of two acidic residues at the spike tip to an alanine greatly reduced the binding affinity. Transfection of hepatoma cells with a replication-competent HBV plasmid gave significantly reduced production of virus in the presence of peptide, in a dose-dependent manner. These experiments show that the interaction of L-HBsAg with core particles is critical for HBV assembly, and give proof of principle for its disruption in vivo by small molecules.

Chimeric brains generated by intraventricular transplantation of fetal human brain cells into embryonic rats

Limited experimental access to the central nervous system (CNS) is a key problem in the study of human neural development, disease, and regeneration. We have addressed this problem by generating neural chimeras composed of human and rodent cells. Fetal human brain cells implanted into the cerebral ventricles of embryonic rats incorporate individually into all major compartments of the brain, generating widespread CNS chimerism. The human cells differentiate into neurons, astrocytes, and oligodendrocytes, which populate the host fore-, mid-, and hindbrain. These chimeras provide a unique model to study human neural cell migration and differentiation in a functional nervous system.

Growth and fate of PSA-NCAM+ precursors of the postnatal brain

Oligodendrocyte-type 2 astrocyte (O-2A) lineage cells are derived from multipotential stem cells of the developing CNS. Precursors of O-2A progenitors express the polysialylated (PSA) form of the neural cell adhesion molecule (NCAM) and are detected in neonatal rat brain glial cultures. It is unclear how such PSA-NCAM+ "pre-progenitors" are related to neural stem cells and whether they still have the potential to differentiate along several neural lineages. Here we isolated PSA-NCAM+ pre-progenitor cells from glial cultures by immunopanning and found that most of these cells expressed nestin and PDGF-receptor-alpha but not O-2A antigens. PSA-NCAM+ cells synthesized transcripts for fibroblast growth factor (FGF) receptors 1, 2, and 3 and responded to FGF2 by survival and proliferation, growing into large clusters resembling neural spheres. FGF2-induced proliferation of PSA-NCAM+ pre-progenitors was significantly enhanced by thyroid hormone (T3), which on its own did not increase cell survival or mitosis. After adhesion and withdrawal of the mitogen, spheres generated mostly oligodendrocytes and astrocytes but very rarely neurons. PSA-NCAM immunopanned cells grown in epidermal growth factor (EGF) also adopted a mostly glial fate after differentiation. In contrast, PSA-NCAM-negative cells and striatal neonatal stem cells, grown in EGF or FGF2, generated the three CNS cell types. Like neural stem cells, PSA-negative cells generated more oligodendrocytes and fewer neurons when expanded in FGF2 and T3. Thus emergence of PSA-NCAM at the surface of neonatal brain precursors coincides with their restriction to a glial fate. T3 modulates these events by enhancing PSA-NCAM+ pre-progenitor growth in FGF2 and favoring an oligodendrocyte fate.

Influence of bromodeoxyuridine radiosensitization on malignant glioma patient survival: a retrospective comparison of survival data from the Northern California Oncology Group (NCOG) and Radiation Therapy Oncology Group trials (RTOG) for glioblastoma multiforme and anaplastic astrocytoma

PURPOSE

To examine the effect of treatment using Bromodeoxyuridine (BrdU) during radiation therapy on malignant glioma patient survival by comparing historical survival data from several large clinical trials.

METHODS

A retrospective analysis of patient data from Radiation Therapy Oncology Group (RTOG) trials 74-01, 79-18, and 83-02 and the Northern California Oncology Group (NCOG) study 6G-82-1 was conducted. Patient data was supplied by both groups, and analyzed by the RTOG. Pretreatment characteristics including age, extent of surgery, Karnofsky Performance Status (KPS), and histopathology were collected; the only treatment variable evaluated was the use of BrdU during radiation therapy. Radiation dose, dose-fractionation schedule, use of chemotherapy, and/or type of chemotherapy was not controlled for in the analyses. Univariate and multivariate analyses were conducted to examine the potential treatment effect of BrdU on patient survival.

RESULTS

Data from 334 patients treated with BrdU on NCOG 6G-82-1 and 1743 patients treated without BrdU on 3 RTOG studies was received. Patients were excluded from the review if confirmation of eligibility could not be obtained, if the patient was ineligible for the study they entered, if central pathology review was not done, or if radiotherapy data was not available. Patients treated according to the RTOG studies had to start radiotherapy within 4 weeks of surgery; no such restriction existed for the NCOG studies. To ensure comparability between the studies, patients from the NCOG studies who began treatment longer than 40 days from surgery were also excluded. The final data set included 296 cases from the NCOG studies (89%) and 1478 cases from the RTOG studies (85%). For patients with glioblastoma multiforme (GBM) the median survival was 9.8 months in the RTOG studies and 13.0 months in the NCOG trial (p < 0.0001). For patients with AA the median survival was 35.1 months for the RTOG studies and 42.8 months in the NCOG trial (p = 0.126). Univariate results showed consistent results favoring BrdU among patients over 30 years of age, across the extent of surgery, and for GBM patients. A proportional hazards regression model that included treatment, histopathology, KPS, age, and extent of surgery demonstrated that treatment with BrdU was included in the best model only for the GBM group of patients (risk ratio 0.83).

CONCLUSIONS

Because of the heterogeneity of the treatment groups, including potentially important differences in pathology reviewers assessment of nonglioblastoma cases, differences in radiation dose and schedules, and chemotherapy during or after radiation, these analyses cannot provide the definitive answer as to whether BrdU given during radiation therapy improves survival in patients with malignant glioma. There does appear to be a favorable treatment effect seen in patients with GBM, with a lesser effect in patients with AA.

The need for assessment of sedation in the critically ill

There is a need for assessment of sedation in ICU as sedative agents are potent drugs that are used frequently but not regularly monitored for their efficacy. Critical care nurses are accountable when administering potent intravenous drugs, such as sedative agents. This paper examines the rationale behind the use of sedation in ICU. A number of sedative drugs commonly used in ICU, such as propofol, are highlighted. Sedation assessment tools available are considered but each may be appropriate in different situations.

Organisation of basement membrane components in the human adult and fetal pituitary gland and in pituitary adenomas

Cell-matrix interactions undoubtedly have a role in the development and maintenance of the complex nonrandom structure of the human pituitary gland. We have extended previous studies by documenting the patterns of immunoreactivity for type IV collagen, laminin and fibronectin in the fetal gland, comparing these with the adult patterns. In both we have examined the differences between the anterior lobe and intermediate zone in an attempt to elucidate the apparent differences in functional response between corticotrophs in the two areas. We have also examined expression of these proteins in a series of pituitary adenomas. Finally, we have immunolocalised beta 4 integrin, a component of the alpha 6 beta 4 laminin receptor, in the adult gland and in adenomas. In the anterior lobe of the adult gland, type IV collagen and laminin were present in both epithelial and vascular basement membrane. Fibronectin was related to the basement membrane but showed a less continuous distribution. beta 4 Integrin was expressed on the basal aspects of pituitary cells, in association with laminin, suggesting that this did identify the alpha 6 beta 4 laminin receptor. In addition, immunoreactivity was present on the lateral margins of some pituitary cells, which might indicate a role in cell-cell adhesion. None of the proteins showed specific association with any particular cell type, suggesting that these specific interactions do not regulate differentiation. This pattern of expression had developed in the fetal gland by the second trimester, with expression relating to vessels preceding that in epithelial basement membrane. Type IV collagen, laminin and fibronectin were also expressed in epithelial and vascular basement membrane in the intermediate zone of the adult gland, and around Rathke's cleft in the fetal gland. However, the organisation differed, with larger groups of cells enclosed within a single basement membrane. Possible vascular connections demonstrated between the posterior lobe and the intermediate zone would permit access of posterior lobe hormones to this zone. Our data confirmed disruption of expression in pituitary adenomas, type IV collagen, laminin and beta 4 integrin having a mainly perivascular distribution, with more variable immunoreactivity for fibronectin.