Activation of Galpha s mediates induction of tissue-type plasminogen activator gene transcription by epoxyeicosatrienoic acids

The epoxyeicosatrienoic acids (EETs) are products of cytochrome P450 (CYP) epoxygenases that have vasodilatory and anti-inflammatory properties. Here we report that EETs have additional fibrinolytic properties. In vascular endothelial cells, physiological concentrations of EETs, particularly 11,12-EET, or overexpression of the endothelial epoxygenase, CYP2J2, increased tissue plasminogen activator (t-PA) expression by 2.5-fold without affecting plasminogen activator inhibitor-1 expression. This increase in t-PA expression correlated with a 4-fold induction in t-PA gene transcription and a 3-fold increase in t-PA fibrinolytic activity and was blocked by the CYP inhibitor, SKF525A, but not by the calcium-activated potassium channel blocker, charybdotoxin, indicating a mechanism that does not involve endothelial cell hyperpolarization. The t-PA promoter is cAMP-responsive, and induction of t-PA gene transcription by EETs correlated with increases in intracellular cAMP levels and, functionally, with cAMP-driven promoter activity. To determine whether increases in intracellular cAMP levels were due to modulation of guanine nucleotide-binding proteins, we assessed the effects of EETs on Galpha(s) and Galpha(i2). Treatment with EETs increased Galpha(s), but not Galpha(i2), GTP-binding activity by 3.5-fold. These findings indicate that EETs possess fibrinolytic properties through the induction of t-PA and suggest that endothelial CYP2J2 may play an important role in regulating vascular hemostasis.

Differences by gender and sexual experience in adolescent sexual behavior: implications for education and HIV prevention

Researchers examined individual characteristics and peer influences related to adolescents' sexual behavior, taking gender and sexual experience into account. As part of a larger, longitudinal study investigating youth health awareness, 8th, 9th, and 10th graders reported their intentions to engage in sexual activity and use condoms in the next year, the amount of pressure they felt to engage in sexual activity, and their perceptions about the number of their peers engaging in sexual activity. Findings suggest intentions to engage in sexual behavior and use condoms, feelings of pressure to have sex, and perceptions about the number of friends engaging in sexual intercourse differ by gender and sexual experience status. Implications of these findings for health and sexuality education, as well as HIV prevention programs targeted at adolescents, are discussed.

Woman-centred care

Changes over the past decade have emphasised the individual service user and their relationship with the health service. Within the maternity services this has been interpreted as woman-centred care a result of key initiatives; the Winterton Report (House of Commons, 1992. Maternity Services. Second Report of the Health Committee (Winterton Report), Vol. 1. HMSO, London) and Changing Childbirth (DoH, 1993a, Changing childbirth: reports of the expert maternity group parts 1 & 2. HMSO, London). Changing Childbirth outlined key principles of the maternity services and the need for the woman (and her partner, if she wishes) to be the focus of care. The key principles are choice, continuity and control. High quality care depends on the recognition of individuals as having unique needs which continues to be reflected within contemporary policy documents (DoH, 1997, The new NHS: modern and dependable. HMSO, London). This paper presents findings related to the provision of woman-centred care from a national research and development study. The study design incorporated (i): a national survey which was undertaken with midwives, midwife supervisors and doctors; and (ii): in-depth case studies in which information was obtained through interviews with midwives, midwife supervisors, educators, managers, doctors and mothers. Midwives, at all levels, are involved in changing maternity service provision and adapting to new systems of care which aim to increase continuity of care and carer for the woman. The researchers sought to understand how woman-centred care was interpreted and experienced in practice. The findings have been used to identify the continuing educational needs of midwives, and to develop an open learning educational package to meet identified need. The curriculum was designed to enhance the move towards the provision of a more integrated woman-centred service.

The association between substance use, unplanned sexual intercourse and other sexual behaviours among adolescent students

AIMS

To determine the prevalence of high-risk sexual behaviours and the influence of substance use and unplanned sexual intercourse on multiple sexual partners, inconsistent condom use and reasons for not always using condoms among adolescent students.

DESIGN

A standardized self-reported anonymous questionnaire administered to a representative sample of students.

SETTING

The Canadian provinces of Nova Scotia, New Brunswick, Newfoundland and Labrador, and Prince Edward Island in 1998.

PARTICIPANTS

9997 students in grades 9, 10 and 12 in the public school system.

MEASUREMENTS

Items on sexual intercourse, unplanned sexual intercourse, number of sexual partners, condom use, alcohol use, episodes of binge drinking and drunkenness, cigarette smoking and cannabis use.

FINDINGS

About 37.5% of males and 39.7% of females reported having engaged in sexual intercourse in the 12 months prior to the survey. Of those, 68.0% of males and 61.5% of females reported having engaged in unplanned sexual intercourse, 40.9% of males and 32.1% of females reported having more than one sexual partner, and 49.9% of males and 64.1% of females reported inconsistent condom use. Unplanned sexual intercourse under the influence of alcohol or other drug was found to be an independent risk factor for multiple sexual partners and inconsistent condom use.

CONCLUSION

The demonstration of an association between substance use, unplanned sexual intercourse and other sexual behaviours lends support to a harm minimization approach, including the provision of non-judgemental information and interventions addressing unplanned sexual intercourse under the influence of a substance.

Perceptions of school by two teenage boys with Asperger syndrome and their mothers: a qualitative study

This qualitative study aimed to develop an understanding of the challenges faced by teenage boys with Asperger syndrome and their mothers. A case study approach was used to collect data from two 13-year-old boys who have Asperger syndrome and their mothers in Queensland, Australia. Data were collected through the use of semistructured interviews. The words of the boys and their mothers provide a valuable insight into the personal experiences and feelings of the participants. An inductive approach to data analysis identified four themes: (1) developmental differences; (2) problems associated with the general characteristics of Asperger syndrome (i.e. communication and social difficulties, restricted range of interests, a need for routine); (3) stress; and (4) 'masquerading'. The first three themes relate strongly to the current literature, but the emergence of masquerading is of particular interest in developing a fuller understanding of the experiences of individuals with Asperger syndrome at school.

Soluble epoxide hydrolase regulates hydrolysis of vasoactive epoxyeicosatrienoic acids

The cytochrome P450-derived epoxyeicosatrienoic acids (EETs) have potent effects on renal vascular reactivity and tubular sodium and water transport; however, the role of these eicosanoids in the pathogenesis of hypertension is controversial. The current study examined the hydrolysis of the EETs to the corresponding dihydroxyeicosatrienoic acids (DHETs) as a mechanism for regulation of EET activity and blood pressure. EET hydrolysis was increased 5- to 54-fold in renal cortical S9 fractions from the spontaneously hypertensive rat (SHR) relative to the normotensive Wistar-Kyoto (WKY) rat. This increase was most significant for the 14,15-EET regioisomer, and there was a clear preference for hydrolysis of 14, 15-EET over the 8,9- and 11,12-EETs. Increased EET hydrolysis was consistent with increased expression of soluble epoxide hydrolase (sEH) in the SHR renal microsomes and cytosol relative to the WKY samples. The urinary excretion of 14,15-DHET was 2.6-fold higher in the SHR than in the WKY rat, confirming increased EET hydrolysis in the SHR in vivo. Blood pressure was decreased 22+/-4 mm Hg (P:<0.01) 6 hours after treatment of SHRs with the selective sEH inhibitor N:, N:'-dicyclohexylurea; this treatment had no effect on blood pressure in the WKY rat. These studies identify sEH as a novel therapeutic target for control of blood pressure. The identification of a potent and selective inhibitor of EET hydrolysis will be invaluable in separating the vascular effects of the EET and DHET eicosanoids.

Quality assurance for nursing and midwifery education: an analysis of the approach in England

The main purpose of this paper is to discuss conceptual and policy developments for external quality assurance for nurse and midwifery education in England. The current framework was implemented in the academic year 1998/99, and is the subject of a three year evaluation commissioned by the English National Board for Nursing, Midwifery & Health Visiting (ENB). The methods which are being used to evaluate the quality assurance arrangements will be discussed within the context of nursing and midwifery education and practice. The ultimate aim of professionally accredited nursing and midwifery education is to ensure the development of practitioners who are fit for purpose, practice and award. It follows that the quality assurance processes should have the capacity to demonstrate the extent to which professional education meets this aim. This paper will discuss this issue, with particular emphasis on the collaborative review process which is being undertaken by the Quality Assurance Agency and the statutory body for nursing, midwifery and health visiting education. The paper concludes with a discussion of the changes proposed by the government for nursing and midwifery education, and considers the potential impact for quality assurance of health care education.

Increased CYP2J expression and epoxyeicosatrienoic acid formation in spontaneously hypertensive rat kidney

Epoxyeicosatrienoic acids (EETs) are major products of cytochrome P450 (CYP)-catalyzed metabolism of arachidonic acid in the kidney. The potent effect of EETs on renal vascular tone and tubular ion and water transport implicates their role in the regulation of renal function and blood pressure. The present study was designed to test the hypothesis that CYP-catalyzed EET formation was altered in the spontaneously hypertensive rat (SHR) kidney. The formation of 14,15- and 11,12-EET was approximately 2-fold higher in incubations of arachidonic acid with SHR renal cortical microsomes relative to microsomes from normotensive Wistar-Kyoto (WKY) rats. This was consistent with increased expression of a CYP2J2 immunoreactive protein in the SHR cortex and outer medulla. In contrast, there was no significant difference in the levels of the CYP2E and CYP2C epoxygenases in SHR and WKY kidneys. Protein and RNA analysis suggests that the CYP2J2 immunoreactive protein that is overexpressed in the SHR kidney is distinct from the known rat CYP2J isoforms. EET formation also was documented in vivo from measurements of urinary EET excretion. Importantly, the excretion rates of 14,15-, and 11,12-EETs were 2.5- and 1.8-fold higher, respectively, in SHR than WKY kidney. These studies provide both in vitro and in vivo evidence for increased EET formation in the SHR kidney and identify a novel CYP2J2 immunoreactive protein that is differentially expressed in the hypertensive kidney. In light of the known biological properties of the EETs, these findings may be important in elucidating the mechanisms that control renal vascular tone and tubular ion transport in the SHR.

Long-term supplementation with melatonin delays reproductive senescence in rats, without an effect on number of primordial follicles

The primary objective of the present experiment was to determine if lifelong supplementation with melatonin delayed reproductive senescence through decreased loss of ovarian primordial follicles. Holtzman rats were divided into three treatments on Day 10 after pupping (Day 0 = day of pupping). Treatment 1 pups had access to water, whereas Treatment 2 and 3 pups had access to water containing 10 microg/ml melatonin only at night (Treatment 2) or continuously (Treatment 3). Estrous cycles and weights of pups were monitored at selected times during the experiment; ovaries were removed for histology at 75 and 380 days of age. Vaginal opening in Treatment 2 was delayed (P <.01) compared with Treatments 1 and 3, but there was no difference (P > 0.05) among treatments in percentage of normal length estrous cycles from vaginal opening to 75 days of age. There were fewer (P < 0.001) abnormal-length estrous cycles from 180 to 380 days of age in Treatment 2 as compared with Treatments 1 or 3. There was no effect of treatment (P > 0.05) on number of primordial follicles. In conclusion, nighttime, but not continuous supplementation with melatonin, delayed puberty and reproductive senescence without any effect on number of primordial follicles.

Vascular endothelial growth factor, nitric oxide, and leptin follicular fluid levels correlate negatively with embryo quality in IVF patients

OBJECTIVE(S)

To measure vascular endothelial growth factor (VEGF), nitric oxide (NO) and leptin levels in individual ovarian follicles and to examine their relationships with perifollicular blood flow, follicular metabolic indices, and the developmental potential of the corresponding oocyte and embryo.

DESIGN

Prospective study.

SETTING

Academic, tertiary care institution.

PATIENT(S)

Unselected IVF patients.

INTERVENTION(S)

Color-pulsed Doppler analysis of perifollicular blood flow; determination of partial pressure of oxygen (pO2), partial pressure of carbon dioxide (pCO2), and pH and VEGF, leptin and NO levels in follicular fluid.

MAIN OUTCOME MEASURE(S)

Fertilization and day 3 embryo morphology and cleavage.

RESULT(S)

Fifty-five follicular fluid samples from 16 patients were studied. Mean follicular fluid levels were as follows: VEGF, 1,046+/-863.7 pg/mL (range, <63-3,332.7 pg/mL); NO3/NO2, 34.2+/-12 microM (range, 16.4-76.1 microM); and leptin, 20.1+/-12.1 ng/mL (range, 3.3-52.2 ng/mL). Vascular endothelial growth factor had a negative correlation with embryo morphology (r = -0.28, P = .01). Leptin demonstrated a negative correlation with follicular pO2 (r = -0.42, P = .005) and a positive correlation with follicular pCO2 (r = 0.36, P = .02). Follicular leptin levels correlated positively with VEGF levels (r = 0.46, P = .008) and with NO3/NO2 levels (r = 0.39, P =.006).

CONCLUSION(S)

Vascular endothelial growth factor, NO and leptin appear to be markers of follicular hypoxia and suboptimal embryo development. Whether fluctuations of these regulatory factors determine or reflect changes in the follicular microenvironment affecting oocyte developmental potential remains to be elucidated.

Identification and characterization of calcifying valve cells from human and canine aortic valves

BACKGROUND AND AIM OF THE STUDY

Cardiac valve calcification is the predominant pathology in patients needing valve replacement. The aim of this study was to determine if aortic valve cells calcify spontaneously and, if so, to characterize the nodular complex and response to growth factors.

METHODS

Aortic valves were obtained from humans undergoing surgical valve replacement, and from female dogs. The valvular endothelium was removed and explants cultured in medium.

RESULTS

A population of valvular interstitial cells spontaneously formed distinct calcified nodules containing hydroxyapatite within two to three weeks in canine and within six weeks in human aortic valves. The nodules contained an inner ring of dead cells surrounded by an outer ring of living cells. Cells associated with nodules had osteoblast-like characteristics and stained positively for extracellular bone matrix proteins. Incubating canine cells with potential calcifying stimuli tested the stimulus for calcification. The rate of nodule formation was increased with transforming growth factor beta-1 (+25 nodules), 25-hydroxycholesterol (+9 nodules) and bone morphogenetic protein 2 (+4 nodules) as compared with vehicle control (+3 nodules) over 25 days.

CONCLUSIONS

We identified a population of valvular interstitial cells with osteoblast-like characteristics that spontaneously form calcific nodules in cell culture. In addition, the rate of calcific nodule formation was increased with transforming growth factor beta-1 and 25-hydroxycholesterol. Further study of these 'calcifying valve cells' may yield a new in vitro model for testing therapy aimed at preventing calcific valve stenosis.

Soft tissue exposure of endosseous implants between stage I and stage II surgery as a potential indicator of early crestal bone loss

Implants are well accepted as a means of dental rehabilitation. While integration success rates are high, crestal bone loss can occur, and it may not become apparent until stage II surgery and implant uncovering. The purpose of this study was to quantify the relationship between exposure of implants through the oral mucosa between stage I and stage II implant surgery and early changes in crestal bone height. Bone levels were measured during placement of 275 implants in the maxillae of 50 subjects. Repeated bone height measurements were obtained at implant uncovering. Fourteen implants in 7 patients were exposed to the oral cavity through the mucosa at stage II surgery. Patients with 1 or more exposed sites demonstrated a likelihood of bone loss 3.9 times greater than patients with nonexposed sites (Fisher exact test, P = .0003). These results suggest that exposure of an implant between stage I and stage II implant surgery might serve as a potential indicator of the occurrence of early bone loss.

Self-Efficacy, Motivation Constructs, and Mathematics Performance of Entering Middle School Students

The objectives of this study were to determine the influence of various motivation variables on task-specific mathematics performance and to explore whether these variables change during the first year of middle school (N = 273). Students' task-specific self-efficacy was the only motivation variable to predict performance and did so both at start and end of year. There were no differences in anxiety, self-concept, or self-efficacy for self-regulation between start and end of year, but, by end of year, students described mathematics as less valuable and reported lower effort and persistence. Gifted students had stronger mathematics self-concept beliefs, and they had more accurate and less overconfident self-efficacy beliefs than did regular education students. There were no gender differences in any of the motivation constructs. Copyright 1999 Academic Press.

L- and P-selectin and CD11/CD18 in intracapillary neutrophil sequestration in rabbit lungs

Infusion of complement fragments induces rapid sequestration of neutrophils within pulmonary capillaries. This study examined the mechanisms through which this sequestration occurs, as well as the effect of complement fragments on the expression of L-selectin and CD11/CD18 using ultrastructural immunohistochemistry. Studies using anti-P-selectin antibodies, fucoidin, L-selectin-depleted neutrophils, and anti-CD18 antibodies showed that selectins and CD18 were not required for neutrophil sequestration. However, maintaining the sequestered neutrophils within the pulmonary capillaries required both L-selectin and CD11/CD18. Neutrophils in the pulmonary capillaries of rabbits given complement fragments expressed 72% less L-selectin and 98% more CD11/CD18 than did those in rabbits given saline. Shedding of L-selectin occurred preferentially from the microvillar processes of the plasma membrane rather than from the flat intervening regions. About 28% of L-selectin still remained on intracapillary neutrophil membranes after 15 min and was likely available for binding. Shedding of L-selectin appeared slower in vivo than in vitro. These studies indicate that neutrophil sequestration induced by complement fragments requires at least two sequential steps, one that does not require recognized adhesion molecules followed by a second that requires L-selectin and CD11/ CD18.

The relationship between health status and blood pressure in urban African Americans

African Americans have higher rates of hypertension and poorer health status than their white counterparts. This study assessed the relationship between health status, cardiovascular risk factors, and measured blood pressure. Free blood pressure screenings were performed at businesses and organizations located in west Baltimore. All individuals with cardiovascular risk factors were offered health education. Also, participants with a measured blood pressure of > or = 140/90 mm Hg were referred for free medical treatment. Participants completed a questionnaire that included demographics, cardiovascular risk factors, the Medical Outcomes Study SF 36, and two tests on cholesterol and heart disease knowledge. A total of 1389 African-American men and women were screened; 20% were found to have high normal blood pressure and 31% had stage 1 hypertension or higher. Those with hypertension reported lower physical functioning and poorer general health than those without high blood pressure. When compared with US normative data, participants reported higher levels in vitality and physical and emotional role functioning, more bodily pain, and poorer general health, but they were similar in physical functioning, social functioning, and mental health. Preliminary data suggest that hypertension does have an effect on health function.

Annual cycle in LH and testosterone release in response to GnRH challenge in male woodchucks (Marmota monax)

Testosterone and LH concentrations were determined in serum samples obtained before and 15 min after injections of GnRH (1 microgram kg-1) administered at 4-7 week intervals over 20 months to groups of male woodchucks (n = 6-7) born and maintained in Northern Hemisphere (boreal) versus Southern Hemisphere (austral) simulated natural photoperiods, beginning at 18-24 months of age. Nadir and peak unstimulated testosterone (0.1 +/- 0.01 and 7.0 +/- 0.1 ng ml-1, respectively) and LH (0.8 +/- 0.2 and 8.1 +/- 1.1 ng ml-1, respectively) concentrations did not differ in boreal versus austral males. In the five boreal and five austral males that were confirmed to be photoentrained, basal (pre-GnRH) concentrations of LH and testosterone were lowest in summer, increased simultaneously in late autumn or early winter, and declined in the spring. GnRH stimulated some LH release throughout the year except for a 1-4 month period in the summer. The initial annual increase in the LH response to GnRH occurred in early autumn, and in 17 of 20 cycles it occurred 1-2 months before the initial increase in basal LH was detected. In the three free-running males not entrained to the photoperiod, the endocrine patterns were similar but were advanced by several months. The results demonstrate that in woodchucks there is a late autumn increase in LH secretion associated with the onset of testicular recrudescence, and an early autumn increase in pituitary response to GnRH before a detectable increase in serum testosterone.

Complement fragment-induced release of neutrophils from bone marrow and sequestration within pulmonary capillaries in rabbits

Infusion of complement fragments induces rapid sequestration of neutrophils within the pulmonary capillaries. This study examined the contributions of the bone marrow (BM) and the liver to the accumulation of neutrophils within the lungs. Complement fragments induced the release of neutrophils from the BM within 7 minutes of infusion, and these neutrophils sequestered in the lungs immediately upon reaching the pulmonary capillaries. Neutrophils expressing high levels of L-selectin were preferentially retained within the pulmonary microvasculature. By 30 minutes after the infusion was stopped, the circulating neutrophil counts had increased, primarily because of release from the BM. The number of neutrophils sequestered in the lung had decreased by only 27%, and the number of neutrophils in the liver increased by 223%. These studies indicate that complement fragments induce the release of neutrophils from the BM far more rapidly than previously described. These newly released neutrophils immediately sequester within the lung, increasing the number of neutrophils available to injure the lung many fold beyond the number that were circulating before infusion. The preferential retention of L-selectin-expressing neutrophils likely reflects the requirement for L-selectin-mediated adhesion in maintaining sequestered neutrophils within the pulmonary microvasculature. The number of circulating neutrophils reflects a balance between pulmonary sequestration, rapid release from the BM, and uptake by the liver and other organs.

Anti-HIV agents that selectively target retroviral nucleocapsid protein zinc fingers without affecting cellular zinc finger proteins

Agents that target the two highly conserved Zn fingers of the human immunodeficiency virus (HIV) nucleocapsid p7 (NCp7) protein are under development as antivirals. These agents covalently modify Zn-coordinating cysteine thiolates of the fingers, causing Zn ejection, loss of native protein structure and nucleic acid binding capacity, and disruption of virus replication. Concentrations of three antiviral agents that promoted in vitro Zn ejection from NCp7 and inhibited HIV replication did not impact the functions of cellular Zn finger proteins, including poly(ADP-ribose) polymerase and the Sp1 and GATA-1 transcription factors, nor did the compounds inhibit HeLa nuclear extract mediated transcription. Selectivity of interactions of these agents with NCp7 was supported by molecular modeling analysis which (1) identified a common saddle-shaped nucleophilic region on the surfaces of both NCp7 Zn fingers, (2) indicated a strong correspondence between computationally docked positions for the agents tested and overlap of frontier orbitals within the nucleophilic loci of the NCp7 Zn fingers, and (3) revealed selective steric exclusion of the agents from the core of the GATA-1 Zn finger. Further modeling analysis suggests that the thiolate of Cys49 in the carboxy-terminal finger is the site most susceptible to electrophilic attack. These data provide the first experimental evidence and rationale for antiviral agents that selectively target retroviral nucleocapsid protein Zn fingers.

Osteoradionecrosis of the jaws as a risk factor in radiotherapy: a report of an eight-year retrospective review

Osteoradionecrosis of the jaws is a severe complication of radiotherapy in the treatment of the head and neck neoplasms. The literature indicates a recent decline in the reported incidence of this complication. The purpose of this study was to further assess the incidence rate for osteoradionecrosis. Factors previously associated with an increased risk for osteoradionecrosis were evaluated to determine possible relationships. A retrospective chart review was conducted for 193 patients treated with radiotherapy for malignant head and neck tumors over an eight-year period. Recorded diagnoses of osteoradionecrosis were noted. Factors previously correlated with the development of osteoradionecrosis were assessed. Of the 193 charts reviewed, 9 diagnoses of osteoradionecrosis of the jaws were made representing an incidence rate of 4.7% for the period evaluated. No single factor was noted to be associated with the development of osteoradionecrosis. The results indicate a low incidence rate for osteoradionecrosis as a post-radiation treatment complication. No single causative factor could be identified suggesting a multifactorial interaction responsible for osteoradionecrosis.

Inhibition of acute-, latent-, and chronic-phase human immunodeficiency virus type 1 (HIV-1) replication by a bistriazoloacridone analog that selectively inhibits HIV-1 transcription

Nanomolar concentrations of temacrazine (1,4-bis[3-(6-oxo-6H-v-triazolo[4,5,1-de]acridin-5-yl)amino-propyl ]piperazine) were discovered to inhibit acute human immunodeficiency virus type 1 (HIV-1) infections and suppress the production of virus from chronically and latently infected cells containing integrated proviral DNA. This bistriazoloacridone derivative exerted its mechanism of antiviral action through selective inhibition of HIV-1 transcription during the postintegrative phase of virus replication. Mechanistic studies revealed that temacrazine blocked HIV-1 RNA formation without interference with the transcription of cellular genes or with events associated with the HIV-1 Tat and Rev regulatory proteins. Although temacrazine inhibited the in vitro 3' processing and strand transfer activities of HIV-1 integrase, with a 50% inhibitory concentration of approximately 50 nM, no evidence of an inhibitory effect on the intracellular integration of proviral DNA into the cellular genome during the early phase of infection could be detected. Furthermore, temacrazine did not interfere with virus attachment or fusion to host cells or the enzymatic activities of HIV-1 reverse transcriptase or protease, and the compound was not directly virucidal. Demonstration of in vivo anti-HIV-1 activity by temacrazine identifies bistriazoloacridones as a new class of pharmaceuticals that selectively blocks HIV-1 transcription.