Selective requirement for Src kinases during VEGF-induced angiogenesis and vascular permeability

Src kinase activity was found to protect endothelial cells from apoptosis during vascular endothelial growth factor (VEGF)-, but not basic fibroblast growth factor (bFGF)-, mediated angiogenesis in chick embryos and mice. In fact, retroviral targeting of kinase-deleted Src to tumor-associated blood vessels suppressed angiogenesis and the growth of a VEGF-producing tumor. Although mice lacking individual Src family kinases (SFKs) showed normal angiogenesis, mice deficient in pp60c-src or pp62c-yes showed no VEGF-induced vascular permeability (VP), yet fyn-/- mice displayed normal VP. In contrast, inflammation-mediated VP appeared normal in Src-deficient mice. Therefore, VEGF-, but not bFGF-, mediated angiogenesis requires SFK activity in general, whereas the VP activity of VEGF specifically depends on the SFKs, Src, or Yes.

Low-dose aspirin to prevent preeclampsia in women at high risk. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units

BACKGROUND

Whether low-dose aspirin prevents preeclampsia is unclear. It is not recommended as prophylaxis in women at low risk for preeclampsia but may reduce the incidence of the disease in women at high risk.

METHODS

We conducted a double-blind, randomized, placebo-controlled trial in four groups of pregnant women at high risk for preeclampsia, including 471 women with pregestational insulin-treated diabetes mellitus, 774 women with chronic hypertension, 688 women with multifetal gestations, and 606 women who had had preeclampsia during a previous pregnancy. The women were enrolled between gestational weeks 13 and 26 and received either 60 mg of aspirin or placebo daily.

RESULTS

Outcome data were obtained on all but 36 of the 2539 women who entered the study. The incidence of preeclampsia was similar in the 1254 women in the aspirin group and the 1249 women in the placebo group (aspirin, 18 percent; placebo, 20 percent; P=0.23). The incidences in the aspirin and placebo groups for each of the four high-risk categories were also similar: for women with pregestational diabetes mellitus, the incidence was 18 percent in the aspirin group and 22 percent in the placebo group (P=0.38); for women with chronic hypertension, 26 percent and 25 percent (P= 0.66); for those with multifetal gestations, 12 percent and 16 percent (P=0.10); and for those with preeclampsia during a previous pregnancy, 17 percent and 19 percent (P=0.47). In addition, the incidences of perinatal death, preterm birth, and infants small for gestational age were similar in the aspirin and placebo groups.

CONCLUSIONS

In our study, low-dose aspirin did not reduce the incidence of preeclampsia significantly or improve perinatal outcomes in pregnant women at high risk for preeclampsia.

Hypertensive disorders in twin versus singleton gestations. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units

OBJECTIVE

This study was undertaken to compare rates and severity of gestational hypertension and preeclampsia, as well as perinatal outcomes when these complications develop, between women with twin gestations and those with singleton gestations.

STUDY DESIGN

This was a secondary analysis of prospective data from women with twin (n = 684) and singleton (n = 2946) gestations enrolled in two separate multicenter trials of low-dose aspirin for prevention of preeclampsia. End points were rates of gestational hypertension, rates of preeclampsia, and perinatal outcomes among women with hypertensive disorders.

RESULTS

Women with twin gestations had higher rates of gestational hypertension (relative risk, 2.04; 95% confidence interval, 1.60-2.59) and preeclampsia (relative risk, 2. 62; 95% confidence interval, 2.03-3.38). In addition, women with gestational hypertension during twin gestations had higher rates of preterm delivery at both <37 weeks' gestation (51.1% vs 5.9%; P <. 0001) and <35 weeks' gestation (18.2% vs 1.6%; P <.0001) and also had higher rates of small-for-gestational-age infants (14.8% vs 7. 0%; P =.04). Moreover, when outcomes associated with preeclampsia were compared, women with twin gestations had significantly higher rates of preterm delivery at <37 weeks' gestation (66.7% vs 19.6%; P <.0001), preterm delivery at <35 weeks' gestation (34.5% vs 6.3%; P <.0001), and abruptio placentae (4.7% vs 0.7%; P =.07). In contrast, among women with twin pregnancies, those who remained normotensive had more adverse neonatal outcomes than did those in whom hypertensive complications developed.

CONCLUSIONS

Rates for both gestational hypertension and preeclampsia are significantly higher among women with twin gestations than among those with singleton gestations. Moreover, women with twin pregnancies and hypertensive complications have higher rates of adverse neonatal outcomes than do those with singleton pregnancies.

Src deficiency or blockade of Src activity in mice provides cerebral protection following stroke

Vascular endothelial growth factor (VEGF), an angiogenic factor produced in response to ischemic injury, promotes vascular permeability (VP). Evidence is provided that Src kinase regulates VEGF-mediated VP in the brain following stroke and that suppression of Src activity decreases VP thereby minimizing brain injury. Mice lacking pp60c-src are resistant to VEGF-induced VP and show decreased infarct volumes after stroke whereas mice deficient in pp59c-fyn, another Src family member, have normal VEGF-mediated VP and infarct size. Systemic application of a Src-inhibitor given up to six hours following stroke suppressed VP protecting wild-type mice from ischemia-induced brain damage without influencing VEGF expression. This was associated with reduced edema, improved cerebral perfusion and decreased infarct volume 24 hours after injury as measured by magnetic resonance imaging and histological analysis. Thus, Src represents a key intermediate and novel therapeutic target in the pathophysiology of cerebral ischemia where it appears to regulate neuronal damage by influencing VEGF-mediated VP.

The spatial arrangement of chromosomes during prometaphase facilitates spindle assembly

Error-free chromosome segregation requires stable attachment of sister kinetochores to the opposite spindle poles (amphitelic attachment). Exactly how amphitelic attachments are achieved during spindle assembly remains elusive. We employed photoactivatable GFP and high-resolution live-cell confocal microscopy to visualize complete 3D movements of individual kinetochores throughout mitosis in nontransformed human cells. Combined with electron microscopy, molecular perturbations, and immunofluorescence analyses, this approach reveals unexpected details of chromosome behavior. Our data demonstrate that unstable lateral interactions between kinetochores and microtubules dominate during early prometaphase. These transient interactions lead to the reproducible arrangement of chromosomes in an equatorial ring on the surface of the nascent spindle. A computational model predicts that this toroidal distribution of chromosomes exposes kinetochores to a high density of microtubules which facilitates subsequent formation of amphitelic attachments. Thus, spindle formation involves a previously overlooked stage of chromosome prepositioning which promotes formation of amphitelic attachments.

Speech and prosody characteristics of adolescents and adults with high-functioning autism and Asperger syndrome

Speech and prosody-voice profiles for 15 male speakers with High-Functioning Autism (HFA) and 15 male speakers with Asperger syndrome (AS) were compared to one another and to profiles for 53 typically developing male speakers in the same 10- to 50-years age range. Compared to the typically developing speakers, significantly more participants in both the HFA and AS groups had residual articulation distortion errors, uncodable utterances due to discourse constraints, and utterances coded as inappropriate in the domains of phrasing, stress, and resonance. Speakers with AS were significantly more voluble than speakers with HFA, but otherwise there were few statistically significant differences between the two groups of speakers with pervasive developmental disorders. Discussion focuses on perceptual-motor and social sources of differences in the prosody-voice findings for individuals with Pervasive Developmental Disorders as compared with findings for typical speakers, including comment on the grammatical, pragmatic, and affective aspects of prosody.

Matrix metalloproteinases contribute to the blood-brain barrier disruption during bacterial meningitis

In this study, we investigated the involvement of matrix metalloproteinases (MMPs) in the pathophysiology of bacterial meningitis. By using an enzyme immunoassay, high concentrations of MMP-9 were detected in the cerebrospinal fluid (CSF) of adult patients with bacterial meningitis but not in controls, and in patients with Guillain-Barré syndrome. Moreover, we observed significantly elevated concentrations of the tissue inhibitor of metalloproteinase-1 (TIMP-1) in the CSF of patients with bacterial meningitis, compared with controls. In a rat model of meningococcal meningitis, intracisternal injection of heat-killed meningococci caused a disruption of the blood-brain barrier (BBB), an increase in intracranial pressure, and CSF pleocytosis paralleled by the occurrence of MMP-9 activity in the CSF 6 hours after meningococcal challenge. The MMP inhibitor batimastat (BB-94) significantly reduced the BBB disruption and the increase in intracranial pressure irrespective of the time of batimastat administration (15 minutes before and 3 hours after meningococcal challenge) but failed to significantly reduce CSF white blood cell counts. In conclusion, our results suggest that MMPs are involved in the alterations of BBB permeability during experimental meningococcal meningitis.

Assessment of hemolysis related quantities in a microaxial blood pump by computational fluid dynamics

A computational assessment or even quantification of shear induced hemolysis in the predesign phase of artificial organs (e.g., cardiac assist devices) would largely decrease efforts and costs of design and development. In this article, a general approach of hemolysis analysis by means of computational fluid dynamics (CFD) is discussed. A validated computational model of a microaxial blood pump is used for detailed analysis of shear stress distribution. Several methods are presented that allow for a qualitative assessment of shear stress distribution and related exposure times using a Lagrangian approach and mass distribution in combination with shear stress analysis. The results show that CFD offers a convenient tool for the general assessment of shear-induced hemolysis. The determination of critical regions and an estimation of the amount of blood subject to potential damage in relation to the total mass flow are shown to be feasible. However, awareness of limitations and potential flaws in CFD based hemolysis assessments is crucial.

The effect of the oxytocin antagonist atosiban on preterm uterine activity in the human

OBJECTIVE

The purpose of this study was to test the hypothesis that infusion of the oxytocin antagonist atosiban results in decreased preterm uterine activity in the human.

STUDY DESIGN

A randomized, double-blind, placebo-controlled trial was performed. One hundred twenty women from 20 to 36 weeks' gestation with a complaint of labor who had more than four uterine contractions per hour after intravenous hydration but no evidence of cervical changes were randomized to receive a 2-hour intravenous infusion of atosiban at a rate of 300 micrograms/min or placebo. Ond hundred-twelve subjects (56 in each arm) were suitable for analysis of efficacy. Both groups remained at bed rest and received hydration.

RESULTS

The mean percent decrease in contraction frequency was greater in atosiban subjects compared with controls (55.3% +/- 36.3% vs 26.7% +/- 40.4%, mean +/- SD, p < 0.001). A minimal (< 20%) decrease or an increase in contraction frequency was noted in 25 placebo subjects (45%) and seven atosiban subjects (13%). There was no clinically or statistically significant change in maternal blood pressure or heart rate during the infusion. The only adverse experiences possibly related to the drug were nausea and vomiting in one atosiban patient.

CONCLUSION

A 2-hour infusion of the oxytocin antagonist atosiban resulted in a significantly greater decline in contraction frequency compared with controls. Oxytocin appears to play a role in the maintenance of preterm uterine activity in the human.

Timing of centrosome separation is important for accurate chromosome segregation

Spindle assembly, establishment of kinetochore attachment, and sister chromatid separation must occur during mitosis in a highly coordinated fashion to ensure accurate chromosome segregation. In most vertebrate cells, the nuclear envelope must break down to allow interaction between microtubules of the mitotic spindle and the kinetochores. It was previously shown that nuclear envelope breakdown (NEB) is not coordinated with centrosome separation and that centrosome separation can be either complete at the time of NEB or can be completed after NEB. In this study, we investigated whether the timing of centrosome separation affects subsequent mitotic events such as establishment of kinetochore attachment or chromosome segregation. We used a combination of experimental and computational approaches to investigate kinetochore attachment and chromosome segregation in cells with complete versus incomplete spindle pole separation at NEB. We found that cells with incomplete spindle pole separation exhibit higher rates of kinetochore misattachments and chromosome missegregation than cells that complete centrosome separation before NEB. Moreover, our mathematical model showed that two spindle poles in close proximity do not "search" the entire cellular space, leading to formation of large numbers of syntelic attachments, which can be an intermediate stage in the formation of merotelic kinetochores.

Risks of preeclampsia and adverse neonatal outcomes among women with pregestational diabetes mellitus. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units

OBJECTIVES

This study was undertaken to determine the frequencies of preeclampsia and adverse neonatal outcomes among women with pregestational diabetes.

STUDY DESIGN

This was a prospective observation of pregnancy outcomes among 462 women with pregestational diabetes mellitus (White classes B-F) and singleton pregnancies who were enrolled in a multicenter trial to compare low-dose aspirin with placebo for preeclampsia prevention. The main outcome measures were preeclampsia and neonatal outcomes.

RESULTS

Among 462 women with pregestational diabetes, 92 (20%) had preeclampsia. Preeclampsia frequency rose significantly with increasing severity of diabetes according to White classification (class B, 11%; class C, 22%; class D, 21%; class R plus class F, 36%; P <.0001). Preeclampsia was also more common among women who had proteinuria at baseline (28% vs 18%; odds ratio, 1.75; 95% confidence interval, 1.02-3.01). Frequency of preterm delivery at <35 weeks' gestation rose greatly with increasing severity of diabetes (P =.0002). Women with proteinuria at baseline were significantly more likely to be delivered at <35 weeks' gestation (29% vs 13%; odds ratio, 2.6; 95% confidence interval, 1.5-4.6) and to have small-for-gestational-age infants (14% vs 3%; odds ratio, 5. 4; 95% confidence interval, 2.7-17.7), and they were less likely to have large-for-gestational-age infants (14% vs 40%; odds ratio, 0.2; 95% confidence interval, 0.1-0.5).

CONCLUSION

Among women with pregestational diabetes mellitus, the frequency of preeclampsia rose with increasing severity of diabetes. Proteinuria early in pregnancy was associated with marked increases in adverse neonatal outcomes independent of preeclampsia development.

Neuronal activity in narcolepsy: identification of cataplexy-related cells in the medial medulla

Narcolepsy is a neurological disorder characterized by sleepiness and episodes of cataplexy. Cataplexy is an abrupt loss of muscle tone, most often triggered by sudden, strong emotions. A subset of cells in the medial medulla of the narcoleptic dog discharged at high rates only in cataplexy and rapid eye movement (REM) sleep. These cells were noncholinergic and were localized to ventromedial and caudal portions of the nucleus magnocellularis. The localization and discharge pattern of these cells indicate that cataplexy results from a triggering in waking of the neurons responsible for the suppression of muscle tone in REM sleep. However, most medullary cells were inactive during cataplexy but were active during REM sleep. These data demonstrate that cataplexy is a distinct behavioral state, differing from other sleep and waking states in its pattern of brainstem neuronal activity.

Experimental pneumococcal meningitis: cerebrovascular alterations, brain edema, and meningeal inflammation are linked to the production of nitric oxide

We investigated whether treatment with the nitric oxide synthase inhibitor N-nitro-L-arginine (L-NA) and the free radical scavenger superoxide dismutase influences cerebral blood flow changes, brain edema, and cerebrospinal fluid pleocytosis in early experimental pneumococcal meningitis. Compared to untreated infected rats, superoxide dismutase given 3 hours after infection significantly attenuated the increase of brain water content, intracranial pressure, and cerebrospinal fluid white blood cell count, but did not modulate the increase in regional cerebral blood flow. N-Nitro-L-arginine treatment (5 mg/kg intravenously, followed by 5 mg/kg/hour) reversed the increase in regional cerebral blood flow; prevented an increase in brain water content, intracranial pressure, and cerebrospinal fluid nitrite concentrations; and reduced cerebrospinal fluid white blood cell count. With a closed cranial window preparation, N-nitro-L-arginine prevented pneumococci-induced dilatation of pial arterioles. When the effective dose was increased twofold, the effects of N-nitro-L-arginine became more pronounced but resulted in the death of 4 of 5 rats, probably due to hemodynamic side effects. In primary cultures of rat cerebral endothelial cells, nitrite concentrations increased after pneumococcal stimulation, which could be prevented by N-nitro-L-arginine and cycloheximide. These data suggest that (a) nitric oxide accounts for regional cerebral blood flow changes and pial arteriolar dilatation in the early phase of experimental pneumococcal meningitis; (b) both superoxide radical and nitric oxide are involved as mediators of brain edema and meningeal inflammation; and (c) cerebral endothelial cells can be stimulated by pneumococci to release nitric oxide presumably via the inducible nitric oxide synthase.

Adenoviral vector-mediated gene transfer for human gene therapy

Human gene therapy promises to change the practice of medicine by treating the causes of disease rather than the symptoms. Since the first clinical trial made its debut ten years ago, there are over 400 approved protocols in the United States alone, most of which have failed to show convincing data of clinical efficacy. This setback is largely due to the lack of efficient and adequate gene transfer vehicles. With the recent progress in elucidating the molecular mechanisms of human diseases and the imminent arrival of the post genomic era, there are increasing numbers of therapeutic genes or targets that are available for gene therapy. Therefore, the urgency and need for efficacious gene therapies are greater than ever. Clearly, the current fundamental obstacle is to develop delivery vectors that exhibit high efficacy and specificity of gene transfer. Recombinant adenoviruses have provided a versatile system for gene expression studies and therapeutic applications. Of late, there has been a remarkable increase in adenoviral vector-based clinical trials. Recent endeavors in the development of recombinant adenoviral vectors have focused on modification of virus tropism, accommodation of larger genes, increase in stability and control of transgene expression, and down-modulation of host immune responses. These modifications and continued improvements in adenoviral vectors will provide a great opportunity for human gene therapy to live up to its enormous potential in the second decade.

Antibiotic treatment of preterm labor with intact membranes: a multicenter, randomized, double-blinded, placebo-controlled trial

OBJECTIVE

Although an association between subclinical intrauterine infection and preterm birth is well established, there is conflicting evidence regarding the benefits of antibiotic administration to women in preterm labor with intact membranes. We attempted to determine the effect of ampicillin-amoxicillin and erythromycin treatment on prolongation of pregnancy, the rate of preterm birth, and neonatal morbidity in patients with preterm labor and intact membranes.

STUDY DESIGN

A multicenter, randomized, double-blinded, placebo-controlled trial was designed and implemented by the Maternal-Fetal Medicine Units Network of the National Institute of Child Health and Human Development. Two hundred seventy-seven women with singleton pregnancies and preterm labor with intact membranes (24 to 34 weeks) were randomly allocated to receive either antibiotics or placebos.

RESULTS

Of the 2373 patients screened for participation in this study in six medical centers, 277 women were enrolled (n = 133 for antibiotics group vs n = 144 for placebo group). In each study group, 60% of patients completed all the study medications. The overall prevalence of microbial invasion of the amniotic cavity was 5.8% (14/239). No significant difference between the antibiotic group and the placebo group was found in maternal outcomes, including duration of randomization-to-delivery interval, frequency of preterm delivery (< 37 weeks), frequency of preterm premature rupture of membranes, clinical chorioamnionitis, endometritis, and number of subsequent admissions for preterm labor. Similarly, no significant difference in neonatal outcomes could be detected between the two groups including respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular hemorrhage, sepsis, and admission and duration of newborn intensive special care unit hospitalization.

CONCLUSION

The results of this study do not support the routine use of antibiotic administration to women in preterm labor with intact membranes.

Predictors of pre-eclampsia in women at high risk. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units

OBJECTIVE

We assessed several variables as predictors for pre-eclampsia risk in a group of women at high risk.

STUDY DESIGN

We studied 2503 women with either diabetes mellitus, chronic hypertension, multifetal gestation, or pre-eclampsia in a previous pregnancy who participated in a multicenter study comparing aspirin and placebo in preventing pre-eclampsia. We evaluated multiple variables for predicting pre-eclampsia risk with use of univariate and multivariable analysis.

RESULTS

Parity and mean arterial pressure at randomization were most predictive of pre-eclampsia risk. The risk was 8% with a mean arterial pressure at enrollment of <75 mm Hg versus 27% with a mean arterial pressure >85 mm Hg (relative risk and 95% confidence interval 3.3 [2.4 to 4.4]). The risk of pre-eclampsia was 26% in nulliparous patients versus 17% in parous subjects (relative risk and 95% confidence interval 1.5 [1.3-1.8]).

CONCLUSIONS

The finding that second-trimester mean arterial pressure affects pre-eclampsia risk suggests that the pathophysiologic process of preeclampsia is initiated before that time.

Ets-1 is an early response gene activated by ET-1 and PDGF-BB in vascular smooth muscle cells

Ets-1 is a transcription factor that activates expression of matrix-degrading proteinases such as collagenase and stromelysin. To study the control of ets-1 gene expression in rat vascular smooth muscle cells (VSMC), cells were exposed to factors known to regulate VSMC migration and proliferation. Platelet-derived growth factor-BB (PDGF-BB), endothelin-1 (ET-1), and phorbol 12-myristate 13-acetate (PMA) induced a dose-dependent expression of ets-1 mRNA. These effects were abrogated by inhibition of protein kinase C (PKC) by H-7 or chronic PMA treatment. Ets-1 mRNA was superinduced by PDGF-BB and ET-1 in the presence of cycloheximide. The chelation of intracellular Ca2+ by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester and the depletion of endoplasmic reticulum intracellular Ca2+ concentration ([Ca2+]i) by thapsigargin inhibited PDGF-BB- and ET-1-induced ets-1 mRNA, whereas ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid had no effect. However, [Ca2+]i release alone was not sufficient to increase ets-1 mRNA. Forskolin blocked ET-1-, PDGF-BB-, and PMA-induced ets-1 mRNA, as well as inositol phosphate formation, consistent with an effect through impairment of PKC activation. Inhibitors of ets-1 gene expression, such as H-7 and herbimycin A, inhibited the ET-1 induction of collagenase I mRNA. We propose that ets-1 may be an important element in the orchestration of matrix proteinase expression and of vascular remodeling after arterial injury.

Mice lacking skeletal muscle actin show reduced muscle strength and growth deficits and die during the neonatal period

All four of the muscle actins (skeletal, cardiac, vascular, and enteric) in higher vertebrates show distinct expression patterns and display highly conserved amino acid sequences. While it is hypothesized that each of the muscle isoactins is specifically adapted to its respective tissue and that the minor variations among them have developmental and/or physiological relevance, the exact functional and developmental significance of these proteins remains largely unknown. In order to begin to assess these issues, we disrupted the skeletal actin gene by homologous recombination. All mice lacking skeletal actin die in the early neonatal period (day 1 to 9). These null animals appear normal at birth and can breathe, walk, and suckle, but within 4 days, they show a markedly lower body weight than normal littermates and many develop scoliosis. Null mice show a loss of glycogen and reduced brown fat that is consistent with malnutrition leading to death. Newborn skeletal muscles from null mice are similar to those of wild-type mice in size, fiber type, and ultrastructural organization. At birth, both hemizygous and homozygous null animals show an increase in cardiac and vascular actin mRNA in skeletal muscle, with no skeletal actin mRNA present in null mice. Adult hemizygous animals show an increased level of skeletal actin mRNA in hind limb muscle but no overt phenotype. Extensor digitorum longus (EDL) muscle isolated from skeletal-actin-deficient mice at day 2 to 3 showed a marked reduction in force production compared to that of control littermates, and EDL muscle from hemizygous animals displayed an intermediate force generation. Thus, while increases in cardiac and vascular smooth-muscle actin can partially compensate for the lack of skeletal actin in null mice, this is not sufficient to support adequate skeletal muscle growth and/or function.

Neurocognitive performance enhanced by highly active antiretroviral therapy in HIV-infected women

OBJECTIVE

To determine whether highly active retroviral therapy (HAART) is associated with better neurocognitive outcome over time among HIV-infected women with severely impaired immune function.

METHODS

A semiannual neurocognitive examination on four tasks was administered: Color Trail Making, Controlled Oral Word Association, Grooved Pegboard and Four-Word Learning. This protocol was initiated in the HIV Epidemiological Research study (HERS) study when a woman's CD4 cell count fell to < 100 x 10(6) cells/l. Immune function (CD4), viral load status and depression severity (CESD) were also assessed semi-annually, along with an interview to determine medication intake and illicit drug use.

RESULTS

HAART was not available to any participant at the time of enrollment (baseline), while 44% reported taking HAART at their most recent visit (mean duration of HAART 36.3 +/- 12.6 months). HAART-treated women had improved neurocognitive performance compared with those not treated with HAART. Women taking HAART for 18 months or more showed the strongest neurocognitive performance with improved verbal fluency, psychomotor and executive functions. These functions worsened among women not taking HAART. Substance abuse status, severity of depressive symptoms, age and educational level did not influence the HAART treatment effects on neurocognitive performance. Neurocognitive improvements were strongly associated with the magnitude of CD4 cell count increases.

CONCLUSIONS

HAART appeared to produce beneficial effect on neurocognitive functioning in HIV-infected women with severely impaired immune systems. Benefits were greatest for women who reported receiving HAART for more than 18 months.

Matrix metalloproteinases and tissue inhibitors of metalloproteinases in viral meningitis: upregulation of MMP-9 and TIMP-1 in cerebrospinal fluid

A hallmark of viral meningitis is the invasion of monocytes, lymphocytes and, in the initial phase of the disease, neutrophils into the subarachnoidal space. By their degradation of different macromolecular components in the extracellular connective tissue, matrix metalloproteinases (MMPs) may be essential for the breakdown of the vessel wall in the meninges and the choroid plexus. In this study, the occurrence of MMP-1, MMP-2, MMP-3 and MMP-9 and the two tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-2, was monitored in the cerebrospinal fluid (CSF) from patients with viral meningitis. Of the proteinases, MMP-9 was found in 13 of 39 (33%) patients, but not in controls; the levels being correlated with the neutrophil cell number in CSF. The CSF concentration of TIMP-1 was increased three-fold compared to the control group (median 233 ng/ml; range 9.4-1252.5 ng/ml) and was correlated to the levels of total protein in CSF. Of the other MMPs and TIMPs assayed, MMP-2 and TIMP-2 were constitutively expressed and not upregulated in viral meningitis. High levels of MMP-9 and MMP-2, as measured by ELISA, was associated with high proteolytic activity detected in CSF by zymography. In conclusion, invasion of the leukocytes into the CSF compartment in viral meningitis may involve MMP-9, its proteolytic effect likely being controlled by expression of TIMP-1.

Dynein antagonizes eg5 by crosslinking and sliding antiparallel microtubules

Mitotic spindle assembly requires the combined activity of various molecular motor proteins, including Eg5 and dynein. Together, these motors generate antagonistic forces during mammalian bipolar spindle assembly; what remains unknown, however, is how these motors are functionally coordinated such that antagonism is possible. Given that Eg5 generates an outward force by crosslinking and sliding apart antiparallel microtubules (MTs), we explored the possibility that dynein generates an inward force by likewise sliding antiparallel MTs. We reasoned that antiparallel overlap, and therefore the magnitude of a dynein-mediated force, would be inversely proportional to the initial distance between centrosomes. To capitalize on this relationship, we utilized a nocodazole washout assay to mimic spindle assembly. We found that Eg5 inhibition led to either monopolar or bipolar spindle formation, depending on whether centrosomes were initially separated by less than or greater than 5.5 microm, respectively. Mathematical modeling predicted this same spindle bistability in the absence of functional Eg5 and required dynein acting on antiparallel MTs to do so. Our results suggest that dynein functionally coordinates with Eg5 by crosslinking and sliding antiparallel MTs, a novel role for dynein within the framework of spindle assembly.

Preparation of triazolo[1,5-c]pyrimidines as potential antiasthma agents

With the use of the human basophil histamine release assay, 5-aryl-2-amino[1,2,4]triazolo[1,5-c]pyrimidines were found to be active as mediator release inhibitors. These compounds were prepared by reacting arylamidines with sodium ethyl formylacetate or with ethyl propiolate to give pyrimidinones. Treatment with phosphorus oxychloride gave a chloropyrimidine, which was converted to a hydrazinopyrimidine with hydrazine. Cyclization, using cyanogen bromide, gave the triazolo[1,5-c]pyrimidines, after a Dimroth rearrangement. Following a structure-activity evaluation, the 5-[3-(trifluoromethyl)phenyl]-2-amino (8-10), 5-(3-bromophenyl)-2-amino (8-13), 5-[3-(difluoromethoxy)-phenyl]-2-amino (8-11), and 5-(4-pyridinyl)-2-amino (6-7) compounds were found to have the best activity. They were chosen for further pharmacological and toxicological study.