A randomized, double-blind trial comparing combinations of nevirapine, didanosine, and zidovudine for HIV-infected patients: the INCAS Trial. Italy, The Netherlands, Canada and Australia Study

CONTEXT

Current guidelines recommend that individuals infected with the human immunodeficiency virus type 1 (HIV-1) be treated using combinations of antiretroviral agents to achieve sustained suppression of viral replication as measured by the plasma HIV-1 RNA assay, in the hopes of achieving prolonged remission of the disease. However, until recently, many drug combinations have not led to sustained suppression of HIV-1 RNA.

OBJECTIVE

To compare the virologic effects of various combinations of nevirapine, didanosine, and zidovudine.

DESIGN

Double-blind, controlled, randomized trial.

SETTING

University-affiliated ambulatory research clinics in Italy, the Netherlands, Canada and Australia (INCAS).

PATIENTS

Antiretroviral therapy-naive adults free of the acquired immunodeficiency syndrome with CD4 cell counts between 0.20 and 0.60x10(9)/L (200-600/microL).

INTERVENTION

Patients received zidovudine plus nevirapine (plus didanosine placebo), zidovudine plus didanosine (plus nevirapine placebo), or zidovudine plus didanosine plus nevirapine.

MAIN OUTCOME MEASURE

Plasma HIV-1 RNA.

RESULTS

Of the 153 enrolled patients, 151 were evaluable. At week 8, plasma HIV-1 RNA levels had decreased by log 2.18, 1.55, and 0.90 in the triple drug therapy, zidovudine plus didanosine, and zidovudine plus nevirapine groups, respectively (P<.05). The proportions of patients with plasma HIV-1 RNA levels below 20 copies per milliliter at week 52 were 51%, 12%, and 0% in the triple drug therapy, zidovudine plus didanosine, and zidovudine plus nevirapine groups, respectively (P<.001). Viral amplification was attempted in 59 patients at 6 months. Viral isolation was unsuccessful in 19 (79%) of 24, 10 (53%) of 19, and 5 (31%) of 16 patients in the triple drug therapy, zidovudine plus didanosine, and zidovudine plus nevirapine groups, respectively. Among patients from whom virus could be amplified, resistance to nevirapine was found in all 11 patients receiving zidovudine plus nevirapine and in all 5 patients receiving triple drug therapy. Rates of disease progression or death were 23% (11/47), 25% (13/53), and 12% (6/51) for the zidovudine plus nevirapine, zidovudine plus didanosine, and triple drug therapy groups, respectively (P=.08).

CONCLUSIONS

Triple drug therapy with zidovudine, didanosine, and nevirapine led to a substantially greater and sustained decrease in plasma viral load than the 2-drug regimens studied. Our results also suggest that suppression of viral replication, as demonstrated by a decrease in the plasma HIV-1 RNA load below the level of quantitation of the most sensitive test available, may at least forestall the development of resistance.

Methods for quantifying follicular numbers within the mouse ovary

Accurate estimation of the number of ovarian follicles at various stages of development is an important indicator of the process of folliculogenesis in relation to the endocrine signals and paracrine/autocrine mechanisms that control the growth and maturation of the oocytes and their supporting follicular cells. There are 10-fold or greater differences in follicular numbers per ovary at similar ages and/or strains reported in earlier studies using various methods, leading to difficulties with interpretation of ovarian function in control vs experimental conditions. This study describes unbiased, assumption-free stereological methods for quantification of early and growing follicular numbers in the mouse ovary. A fractionator approach was used to sample a defined fraction of histological sections of adult wild-type ovaries. Primordial and primary follicles were counted independently with the optical and physical disector methods. The fractionator/disector methods, which are independent of follicular size or shape, gave estimations of 1930 ± 286 (S.E.M.) and 2227 ± 101 primordial follicles, and 137 ± 25 and 265 ± 32 primary follicles per ovary at 70 and 100 days of age respectively. From exact counts on serial sections, secondary and later follicular numbers at 100 days of age were estimated at 135 per ovary. Remnants of zona pellucidae (a marker of previous follicular atresia) were estimated using a fractionator/physical disector approach and were approximately 500 per ovary. The application of the quantitative methods described will facilitate an improved understanding of follicular dynamics and the factors that mediate their growth and maturation and allow for a better comparison between different studies.

Brief intervention for harm reduction with alcohol-positive older adolescents in a hospital emergency department

This study evaluated the use of a brief motivational interview (MI) to reduce alcohol-related consequences and use among adolescents treated in an emergency room (ER) following an alcohol-related event. Patients aged 18 to 19 years (N = 94) were randomly assigned to receive either MI or standard care (SC). Assessment and intervention were conducted in the ER during or after the patient's treatment. Follow-up assessments showed that patients who received the MI had a significantly lower incidence of drinking and driving, traffic violations, alcohol-related injuries, and alcohol-related problems than patients who received SC. Both conditions showed reduced alcohol consumption. The harm-reduction focus of the MI was evident in that MI reduced negative outcomes related to drinking, beyond what was produced by the precipitating event plus SC alone.

Infusion of alpha-galactosidase A reduces tissue globotriaosylceramide storage in patients with Fabry disease

Fabry disease is a lysosomal storage disorder caused by a deficiency of the lysosomal enzyme alpha-galactosidase A (alpha-gal A). This enzymatic defect results in the accumulation of the glycosphingolipid globotriaosylceramide (Gb(3); also referred to as ceramidetrihexoside) throughout the body. To investigate the effects of purified alpha-gal A, 10 patients with Fabry disease received a single i.v. infusion of one of five escalating dose levels of the enzyme. The objectives of this study were: (i) to evaluate the safety of administered alpha-gal A, (ii) to assess the pharmacokinetics of i.v.-administered alpha-gal A in plasma and liver, and (iii) to determine the effect of this replacement enzyme on hepatic, urine sediment and plasma concentrations of Gb(3). alpha-Gal A infusions were well tolerated in all patients. Immunohistochemical staining of liver tissue approximately 2 days after enzyme infusion identified alpha-gal A in several cell types, including sinusoidal endothelial cells, Kupffer cells, and hepatocytes, suggesting diffuse uptake via the mannose 6-phosphate receptor. The tissue half-life in the liver was greater than 24 hr. After the single dose of alpha-gal A, nine of the 10 patients had significantly reduced Gb(3) levels both in the liver and shed renal tubular epithelial cells in the urine sediment. These data demonstrate that single infusions of alpha-gal A prepared from transfected human fibroblasts are both safe and biochemically active in patients with Fabry disease. The degree of substrate reduction seen in the study is potentially clinically significant in view of the fact that Gb(3) burden in Fabry patients increases gradually over decades. Taken together, these results suggest that enzyme replacement is likely to be an effective therapy for patients with this metabolic disorder.

High-dose nevirapine: safety, pharmacokinetics, and antiviral effect in patients with human immunodeficiency virus infection

Nevirapine, a potent nonnucleoside reverse transcriptase inhibitor, produces a transient antiviral effect at < or = 200 mg/day due to the selection of resistant virus. To examine if higher levels of nevirapine could produce sustained antiviral activity, its safety, pharmacokinetics, and antiviral activity at 400 mg/day were studied in 21 patients. There was a rapid reduction in immune complex-dissociated p24 antigen and serum human immunodeficiency virus RNA concentration in all patients, and 8 of 10 patients had > 50% reduction at 8 weeks. Nevirapine-resistant virus was isolated from all subjects tested at 12 weeks: The mean plasma trough level (4.0 micrograms/mL [15.8 microM]) exceeded the mean IC50 of resistant virus. Rash developed in 48% of patients and was a dose-limiting toxicity factor in 6. These data suggest that clinical testing of potent antiviral compounds that select for drug-resistant virus is justified to determine if serum levels of drug sufficient to overcome resistant virus can be attained.

Nevirapine, zidovudine, and didanosine compared with zidovudine and didanosine in patients with HIV-1 infection. A randomized, double-blind, placebo-controlled trial. National Institute of Allergy and Infectious Diseases AIDS Clinical Trials Group Protocol 241 Investigators

OBJECTIVE

To study the addition of a third human immunodeficiency virus type 1 (HIV-1) reverse transcriptase inhibitor, nevirapine, to the combination of zidovudine and didanosine.

DESIGN

A 48-week, randomized, double-blind, placebo-controlled trial at 16 AIDS (acquired immunodeficiency syndrome) Clinical Trials Units.

PATIENTS

398 adults who had HIV-1 infection, had 350 or fewer CD4+ T lymphocytes/mm3, and had had more than 6 months of previous nucleoside therapy.

INTERVENTION

1) Either nevirapine or placebo (200 mg/d for 2 weeks, then 400 mg/d thereafter) and 2) open-label zidovudine (600 mg/d) and didanosine (400 mg/d for patients weighing > or = 60 kg).

MEASUREMENTS

CD4+ T lymphocyte counts, time to first HIV-1 disease progression event or death, adverse events, and nevirapine levels in plasma samples taken at random were measured in all patients. Plasma levels of HIV-1 RNA HIV-1 infectivity titer in peripheral blood mononuclear cells; serum p24 antigen levels; and plasma levels of zidovudine and didanosine were measured in patients enrolled at half the study sites.

RESULTS

After 48 weeks of study treatment the patients assigned to the triple-combination regimen (nevirapine, zidovudine, and didanosine) had an 18% higher mean absolute CD4 cell count (95% Cl, 7% to 29%; P = 0.001), a 0.32 log10 lower mean infectious HIV-1 titer in peripheral blood mononuclear cells (Cl, 0.05 to 0.59 log10 infectious units per million cells; P = 0.023), and a 0.25 log10 lower mean plasma HIV-1 RNA level (Cl, 0.03 to 0.48 log10 RNA copies/mL; P = 0.028) than did patients assigned to the double-combination regimen (zidovudine and didanosine). Severe rashes were more common among patients assigned to receive the triple combination (9% compared with 2%; P = 0.002). Risk for disease progression did not differ between the two groups (relative hazard of the triple-combination group, 1.24 [Cl, 0.75 to 2.06]; P > 0.2), although the study had only moderate power to detect a major difference.

CONCLUSIONS

Adding nevirapine to zidovudine and didanosine improved the long-term immunologic and virologic effects of therapy and was associated with severe rash among the patients studied, who had had extensive previous therapy. These results support 1) the continuing development of combinations of more than two antiretroviral drugs to increase and prolong HIV-1 suppression and 2) the potential utility of nevirapine in combination regimens.

Brief intervention for harm reduction with alcohol-positive older adolescents in a hospital emergency department

This study evaluated the use of a brief motivational interview (MI) to reduce alcohol-related consequences and use among adolescents treated in an emergency room (ER) following an alcohol-related event. Patients aged 18 to 19 years (N = 94) were randomly assigned to receive either MI or standard care (SC). Assessment and intervention were conducted in the ER during or after the patient's treatment. Follow-up assessments showed that patients who received the MI had a significantly lower incidence of drinking and driving, traffic violations, alcohol-related injuries, and alcohol-related problems than patients who received SC. Both conditions showed reduced alcohol consumption. The harm-reduction focus of the MI was evident in that MI reduced negative outcomes related to drinking, beyond what was produced by the precipitating event plus SC alone.

Suppression of plasma viral load below 20 copies/ml is required to achieve a long-term response to therapy

BACKGROUND

Current guidelines state that the goal of antiretroviral therapy for HIV-infected individuals is to suppress plasma viral load (pVL) to below 400 copies/ml.

METHODS

Predictors of achieving and maintaining pVL suppression were examined in a randomized trial of combinations of zidovudine, nevirapine and didanosine in patients with CD4+ T cell counts of between 200 and 600 x 10(6) cells/l who were naive to antiretroviral therapy and AIDS-free at enrolment.

RESULTS

One hundred and four patients had pVL > 500 copies/ml at baseline and a pVL nadir below 500 copies/ml. Of these, 77 patients experienced an increase in pVL above 500 copies/ml. The median number of days of pVL suppression to below 500 copies/ml was 285 (42) for patients with pVL nadir < or = (>) 20 copies/ml (P = 00.0001). The relative risk of an increase in pVL above 500 copies/ml associated with a pVL nadir below 20 copies/ml was 0.11 (P = 0.0001). The relative risks of an increase in pVL above 5000 copies/ml associated with a pVL nadir below 20 copies/ml or between 20 and 400 copies/ml were 0.05 [95% confidence interval (CI), 0.02-0.12] and 0.37 (95% CI, 0.23-0.61) respectively, compared with individuals with a pVL nadir > 400 copies/ml. Individuals with a pVL nadir < or = 20 copies/ml were at a significantly lower risk of virologic failure than individuals with a pVL nadir of between 21 and 400 copies/ml (P = 0.0001).

CONCLUSIONS

Our results demonstrate that suppression of pVL below 20 copies/ml is necessary to achieve a long-term antiretroviral response. Our data support the need for a revision of current therapeutic guidelines for the management of HIV infection.

BRG-1 is recruited to estrogen-responsive promoters and cooperates with factors involved in histone acetylation

Several factors that mediate activation by nuclear receptors also modify the chemical and structural composition of chromatin. Prominent in this diverse group is the steroid receptor coactivator 1 (SRC-1) family, which interact with agonist-bound nuclear receptors, thereby coupling them to multifunctional transcriptional coregulators such as CREB-binding protein (CBP), p300, and PCAF, all of which have potent histone acetyltransferase activity. Additionally factors including the Brahma-related gene 1 (BRG-1) that are involved in the structural remodeling of chromatin also mediate hormone-dependent transcriptional activation by nuclear receptors. Here, we provide evidence that these two distinct mechanisms of coactivation may operate in a collaborative manner. We demonstrate that transcriptional activation by the estrogen receptor (ER) requires functional BRG-1 and that the coactivation of estrogen signaling by either SRC-1 or CBP is BRG-1 dependent. We find that in response to estrogen, ER recruits BRG-1, thereby targeting BRG-1 to the promoters of estrogen-responsive genes in a manner that occurs simultaneous to histone acetylation. Finally, we demonstrate that BRG-1-mediated coactivation of ER signaling is regulated by the state of histone acetylation within a cell. Inhibition of histone deacetylation by trichostatin A dramatically increases BRG-1-mediated coactivation of ER signaling, and this increase is reversed by overexpression of histone deacetylase 1. These studies support a critical role for BRG-1 in ER action in which estrogen stimulates an ER-BRG-1 association coupling BRG-1 to regions of chromatin at the sites of estrogen-responsive promoters and promotes the activity of other recruited factors that alter the acetylation state of chromatin.

Quantification of healthy follicles in the neonatal and adult mouse ovary: evidence for maintenance of primordial follicle supply

Proliferation and partial meiotic maturation of germ cells in fetal ovaries is believed to establish a finite, non-renewable pool of primordial follicles at birth. The supply of primordial follicles in postnatal life should be depleted during folliculogenesis, either undergoing atresia or surviving to ovulation. Recent studies of mouse ovaries propose that intra- and extraovarian germline stem cells replenish oocytes and form new primordial follicles. We quantified all healthy follicles in C57BL/6 mouse ovaries from day 1 to 200 using unbiased stereological methods, immunolabelling of oocyte meiosis (germ cell nuclear antigen (GCNA)) and ovarian cell proliferation (proliferating cell nuclear antigen (PCNA)) and electronmicroscopy. Day 1 ovaries contained 7924+/-1564 (s.e.m.) oocytes or primordial follicles, declining on day 7 to 1987+/-203, with 200-800 oocytes ejected from individual ovaries on that day and day 12. Discarded oocytes and those subjacent to the surface epithelium were GCNA-positive indicating their incomplete meiotic maturation. From day 7 to 100 mean numbers of primordial follicles per ovary were not significantly depleted but declined at 200 days to 254+/-71. Mean numbers of all healthy follicles per ovary were not significantly different from day 7 to 100 (range 2332+/-349-3007+/-322). Primordial follicle oocytes were PCNA-negative. Occasional unidentified cells were PCNA-positive with mitotic figures observed in the cortex of day 1 and 12 ovaries. Although we found no evidence for ovarian germline stem cells, our data support the hypothesis of postnatal follicle renewal in postnatal and adult ovaries of C57BL/6 mice.

Olfactory bulb removal eliminates maternal behavior in the mouse

Olfactory bulb removal eliminated maternal behavior in lactating and in virgin mice. The results are in contrast to the generally accepted concept of multisensory control of mammalian maternal behavior.

Management of negative symptoms among patients with schizophrenia attending multiple-family groups

OBJECTIVE

Outcomes for negative symptoms over a one-year period were examined in two groups of patients, one receiving psychoeducational multiple-family group treatment and one receiving standard care.

METHODS

A total of 63 outpatients, ages 18 to 45 years, with DSM-IV diagnoses of schizophrenic disorders were randomly assigned to standard care or multiple-family group psychoeducation treatment at a large mental health center in Spokane, Washington. Treatment assignment was stratified by whether patients were taking typical or atypical antipsychotic medications. Negative symptom status was monitored monthly for one year by raters blind to group assignment and measured as a composite of five symptoms using the Modified Scale for the Assessment of Negative Symptoms.

RESULTS

When the analysis controlled for baseline negative symptoms, participants in the multiple-family group experienced significantly reduced negative symptoms compared with those receiving standard care. Taking atypical antipsychotic medication or having a diagnosis of substance abuse was not associated with the severity of negative symptoms. An additional analysis of the five individual negative symptoms indicated small but consistent group differences on all dimensions except inattention. Negative symptoms were significantly correlated with relapse to acute illness but not with outpatient or inpatient service use.

CONCLUSIONS

The study demonstrated that a psychoeducational multiple-family group intervention was more effective than standard care in managing negative symptoms over a 12-month period. The results are particularly relevant because negative symptoms are associated with relapse, poor social and occupational functioning, cognitive impairment, and lower subjective quality of life.

Antiviral effect and pharmacokinetic interaction between nevirapine and indinavir in persons infected with human immunodeficiency virus type 1

Nevirapine and indinavir have the potential of affecting the pharmacokinetics of each other. In a prospective trial, 24 human immunodeficiency virus (HIV)-infected subjects on stable nucleoside or no therapy were treated with 800 mg of indinavir every 8 h. After 7 days, 200 mg of nevirapine a day was added for 14 days and then increased to 200 mg twice a day. At day 7 (before nevirapine), there was a sevenfold difference among the subjects in indinavir area under the curve (AUC), and there was a significant correlation between indinavir AUC (r2=0.378, P=.019), minimum plasma concentration (Cmin; r2=0.359, P=.023), maximum plasma concentration (Cmax; r2=0.340, P=.028), and plasma HIV RNA decline. Nevirapine significantly reduced median indinavir Cmin (47.5%) and AUC (27.4%) and, to a lesser extent, Cmax (11%). Plasma HIV RNA values were </=20 copies/mL in 10 of 17 (58.8%) subjects at 58 weeks or last visit. These data suggest that indinavir dosing should be dependent on drug exposure and not on cotherapy with nevirapine.

Substituted 1,3,4-thiadiazoles with anticonvulsant activity. 1. Hydrazines

The synthesis and anticonvulsant activity of a series of 2-aryl-5-hydrazino-1,3,4-thiadiazoles are described. The combination of preferred aromatic substituents in the 2-position coupled with alkyl substitution on the hydrazine moiety led to a number of potent compounds lacking sedation, ataxia, or lethality. 5-(2-Biphenylyl)-2-(1-methylhydrazino)-1,3,4-thiadiazole (4m) represents a new class of anticonvulsant agent and compares favorably with the standard drugs phenytoin, phenobarbital, and carbamazepine.

Antihypertensive thiadiazoles. 1. Synthesis of some 2-aryl-5-hydrazino-1,3,4-thiadiazoles with vasodilator activity

Some 2-aryl-5-hydrazino-1,3,4-thiadiazoles have been synthesized and screened for antihypertensive activity. In general, compounds with a 2-substituted phenyl ring had higher activity than their 3- or 4-substituted counterparts or those containing heteroaryl groups. The 2-methylphenyl and 2-ethylphenyl derivatives 7 and 18 were the most potent members of the series. Preliminary studies indicated that the hypotensive action of these compounds was due to a direct relaxant effect on vascular smooth muscle.

Influence of gender, race, and education on patient preferences and receipt of cardiac catheterizations among coronary care unit patients

The extent to which a preference for less aggressive care explains the lower rate of invasive cardiac services for women and African-Americans is unknown. A prospective observational study of 272 patients admitted to the coronary care unit was conducted at a tertiary referral teaching hospital and a community teaching hospital. In stepwise multivariate analysis, having less than a college education, poor cardiac function, not having undergone a previous cardiac catheterization, being a patient in a nonreferral community hospital, and current smoking were positively associated with a patient's stating that he or she would disagree with a physician's recommendation for a cardiac catheterization. The step-wise multivariate model with cardiac catheterization as the dependent variable indicated that being a patient in a referral medical center, patient willingness to accept a physician's recommendation for a cardiac catheterization, severe heart disease, and having attended high school were predictive. Women did not differ from men in their preference for or receipt of cardiac catheterization. Patients in the coronary care unit with lower levels of education were less likely to undergo cardiac catheterization. This association was only partly explained by less educated patients' being less willing to accept a physician's recommendation to undergo cardiac catheterization.

Infants' discrimination of the duration of a rapid spectrum change in nonspeech signals

Two-month-old infants discriminated complex sinusoidal patterns that varied in the duration of their initial frequency transitions. Discrimination of these nonspeech sinusoidal patterns was a function of both the duration of the transitions and the total duration of the stimulus pattern. This contextual effect was observed even though the information specifying stimulus duration occurred after the transitional information. These findings parallel those observed with infants for perception of synthetic speech stimuli. Specialized speech processing capacities are thus not required to account for infants' sensitivity to contextual effects in acoustic signals, whether speech or nonspeech.

Population pharmacokinetics of nevirapine, zidovudine, and didanosine in human immunodeficiency virus-infected patients. The National Institute of Allergy and Infectious Diseases AIDS Clinical Trials Group Protocol 241 Investigators

The population pharmacokinetics of nevirapine (NVP), zidovudine (ZDV), and didanosine (ddI) were evaluated in a total of 175 patients infected with human immunodeficiency virus randomized to receive either a double combination of ZDV plus ddI or a triple combination of NVP plus ZDV plus ddI as a substudy of the AIDS Clinical Trials Group Protocol 241. Levels (approximating 3.5 determinations/patient) of the three drugs in plasma were measured during 44 of a total 48 weeks of study treatment, and a set of potential covariates was available for nonlinear mixed-effect modeling analysis. A one-compartment model with zero-order input and first-order elimination was fitted to the NVP data. Individual oral clearance (CL) and volume of distribution (V) averaged 0.0533 liters/h/kg of body weight and 1.17 liters/kg, respectively. Gender was the only covariate which significantly correlated with the CL of NVP. ZDV and ddI data were described by a two-compartment model with zero-order input and first-order elimination. Individual mean oral CL, VSS (volume of distribution at steady state), and V of ZDV were 1.84 liters/h/kg and 6.68 and 2.67 liters/kg, respectively, with body weight and age as correlates of CL and body weight as a correlate of VSS. The average individual oral CL, VSS, and V of ddI were 1.64 liters/h/kg and 3.56 and 2.74 liters/kg, respectively, with body weight as a significant correlate of both CL and VSS. The relative bioavailability (F) of ZDV and ddI in the triple combination compared to that in the double combination was also evaluated. No significant effects of the combination regimens on the F of ddI were detected (FTRIPLE = 1.05 and FDOUBLE = 1 by definition), but the F of ZDV was markedly reduced by the triple combination, being only 67.7% of that of the double combination. Large (>50%) intraindividual variability was associated with both ZDV and ddI pharmacokinetics. Individual cumulative area under the plasma drug level-time curve of the three drugs was calculated for the entire study period as a measure of drug exposure based on the individual data and the final-model estimates of structural and statistical parameters.

The cell polarity regulator hScrib controls ERK activation through a KIM site-dependent interaction

The cell polarity regulator, human Scribble (hScrib), is a potential tumour suppressor whose loss is a frequent event in late-stage cancer development. Little is yet known about the mode of action of hScrib, although recent reports suggest its role in the regulation of cell signalling. In this study we show that hScrib is a direct regulator of extracellular signal-regulated kinase (ERK). In human keratinocytes, loss of hScrib results in elevated phospho-ERK levels and concomitant increased nuclear translocation of phospho-ERK. We also show that hScrib interacts with ERK through two well-conserved kinase interaction motif (KIM) docking sites, both of which are also required for ERK-induced phosphorylation of hScrib on two distinct residues. Although wild-type hScrib can downregulate activation of ERK and oncogenic Ras co-transforming activity, an hScrib mutant that lacks the carboxy terminal KIM docking site has no such effects. These results provide a clear mechanistic explanation of how hScrib can regulate ERK signalling and begin to explain how loss of hScrib during cancer development can contribute to disease progression.

The peculiar autoimmunity of primary biliary cirrhosis

Autoantibodies to mitochondria (AMA, anti-M2) are a serologic hallmark of primary biliary cirrhosis (PBC). These react with three structurally and functionally related multienzymic complexes, the 2-oxoacid dehydrogenase complexes, but chiefly with the E2 subunit of pyruvate dehydrogenase complex (PDC-E2). Their very dose (95%) and specific association with PBC underpins the autoimmune concept of pathogenesis of that disease, notwithstanding several non-congruent features. Detailed studies, including structural analysis of epitopes, do not disclose how these autoantibodies originate. Their ubiquity in PBC has overshadowed the existence of a second set of relatively PBC-specific autoantibodies to nuclear antigens for which reactants have been cloned and characterized. These include centromeric proteins; proteins of the nuclear pore complex; nuclear dot proteins, which include Sp-100 and the promyelocytic leukemia antigen; and a recently identified autoantigen, SOX13. Certain of these reactants are DNA-binding proteins with transcriptional regulatory activity. Thus serum from individuals with the same clinical syndrome can have autoimmune reactivity to disparate mitochondrial and nuclear constituents in different cellular compartments. Antibody probing of phage displayed random peptide libraries, together with epitope scanning using overlapping sequential octameric peptides from the PDC-E2 sequence, showed that the discontinuous motifs MH, FV(E) and SYP contributed to a predicted conformational antibody epitope in the inner lipoyl domain of PDC-E2.

The primordial follicle reserve is not renewed after chemical or γ-irradiation mediated depletion

Reports indicate that germ-line stem cells present in adult mice can rapidly generate new oocytes and contribute to the primordial follicle reserve following conditions of ovotoxic stress. We further investigated the hypothesis that adult mice have the capacity to generate new oocytes by monitoring primordial follicle numbers throughout postnatal life and following depletion of the primordial follicle reserve by exposure to doxorubicin (DXR), trichostatin A (TSA), or whole-body γ-irradiation. We show that primordial follicle number remains stable in adult C57BL/6 mice between the ages of 25 and 100 days. However, within 2 days of treatment with DXR or TSA, primordial follicle numbers had declined to 65 and 51% respectively (P<0.05-0.01 when compared to untreated controls), with no restoration of follicle numbers evident after 7 days for either treatment. Furthermore, ovaries from mice subjected to sterilizing doses of γ-irradiation (0.45 or 4.5 Gy) revealed complete ablation of all primordial follicles 5 days after treatment, with no indication of follicular renewal. We conclude that neo-folliculogenesis does not occur following chemical or γ-irradiation mediated depletion of the primordial follicle reserve.

Alpha-adrenoreceptor reagents. 2. Effects of modification of the 1,4-benzodioxan ring system on alpha-adrenoreceptor activity

Modification of the 1,4-benzodioxan ring present in RX 781094 has not previously been considered. This paper describes a number of analogues of this ring system, including compounds in which one of the oxygen atoms has been replaced by a methylene group and also those in which the ring size has been changed to give, for example, furan and thiophene derivatives. The dihydrobenzofuranylimidazoline compound 7 is the only analogue possessing presynaptic antagonist potency potency and selectivity comparable to that of 1. In view of this result, a number of derivatives was prepared to determine the structure-activity relationships within this series. Many derivatives, as well as the parent compound 7, were found to possess presynaptic alpha 2-adrenoreceptor antagonist and postsynaptic alpha 1-adrenoreceptor partial agonist properties. Two of the selective presynaptic antagonists, 13 and 14 possess greater potency and selectivity than that possessed by 1. The 5-chloro derivative 25 is twice as potent as after oral administration but only about half as potent when given intravenously.

Induction-maintenance antiretroviral therapy: proof of concept

OBJECTIVE

To investigate the concept of aggressive initial combination therapy followed by reduction to a less demanding maintenance regimen with respect to its potential for sustaining viral suppression.

DESIGN

Durable viral suppression to < 20 HIV RNA copies/ml plasma was achieved with zidovudine-nevirapine-didanosine (ZDV-NVP-ddl) therapy. Potential for sustained antiviral response was explored for patients who began with ZDV-NVP-ddl and subsequently interrupted ddl.

METHODS

Antiretroviral-naive patients were treated with ZDV-NVP, ZDV-ddl, or ZDV-NVP-ddl. Viral load was measured with the Amplicor assay (limit of quantification 400 copies/ml) and by the Ultra Direct assay (limit of quantification 20 copies/ml) when the Amplicor result was < 500 copies/ml. Treatment adherence for each drug was recorded, including all dose adjustments.

RESULTS

Five patients who had begun treatment with ZDV-NVP-ddl discontinued ddl for at least 6 weeks after achieving viral load levels below detection. All were documented to have sustained their viral load at < 20 copies/ml during the ddl interruption. Two patients permanently discontinued ddl, both with sustained viral load below detection for more than 1 year while treated with ZDV NVP. In contrast, no patient initially receiving ZDV-NVP was able to maintain viral load below detection for sustained periods; none had viral load below detection after week 12 of treatment.

CONCLUSIONS

After induction with ZDV-NVP-ddl, patients were able to sustain viral suppression with a regimen (ZDV NVP) that was only transiently effective as initial therapy. There was no evidence of virologic escape, even with the most sensitive measure of plasma viral load.