Reduction of diagnostic and treatment delays reduces rifampicin-resistant tuberculosis mortality in Rwanda

SETTING: In 2005, in response to the increasing prevalence of rifampicin-resistant tuberculosis (RR-TB) and poor treatment outcomes, Rwanda initiated the programmatic management of RR-TB, including expanded access to systematic rifampicin drug susceptibility testing (DST) and standardised treatment.OBJECTIVE: To describe trends in diagnostic and treatment delays and estimate their effect on RR-TB mortality.DESIGN: Retrospective analysis of individual-level data including 748 (85.4%) of 876 patients diagnosed with RR-TB notified to the World Health Organization between 1 July 2005 and 31 December 2016 in Rwanda. Logistic regression was used to estimate the effect of diagnostic and therapeutic delays on RR-TB mortality.RESULTS: Between 2006 and 2016, the median diagnostic delay significantly decreased from 88 days to 1 day, and the therapeutic delay from 76 days to 3 days. Simultaneously, RR-TB mortality significantly decreased from 30.8% in 2006 to 6.9% in 2016. Total delay in starting multidrug-resistant TB (MDR-TB) treatment of more than 100 days was associated with more than two-fold higher odds for dying. When delays were long, empirical RR-TB treatment initiation was associated with a lower mortality.CONCLUSION: The reduction of diagnostic and treatment delays reduced RR-TB mortality. We anticipate that universal testing for RR-TB, short diagnostic and therapeutic delays and effective standardised MDR-TB treatment will further decrease RR-TB mortality in Rwanda.

Antithrombotic treatment tailoring and risk score evaluation in elderly patients diagnosed with an acute coronary syndrome

Age is an important prognostic factor in the outcome of acute coronary syndromes (ACS). A substantial percentage of patients who experience ACS is more than 75 years old, and they represent the fastest-growing segment of the population treated in this setting. These patients present different patterns of responses to pharmacotherapy, namely, a higher ischemic and bleeding risk than do patients under 75 years of age. Our aim was to identify whether the currently available ACS ischemic and bleeding risk scores, which has been validated for the general population, may also apply to the elderly population. The second aim was to determine whether the elderly benefit more from a specific pharmacological regimen, keeping in mind the numerous molecules of antiplatelet and antithrombotic drugs, all validated in the general population. We concluded that the GRACE (Global Registry of Acute Coronary Events) risk score has been extensively validated in the elderly. However, the CRUSADE (Can Rapid risk stratification of Unstable angina patients Suppress ADverse outcomes with Early implementation of the ACC/AHA Guidelines) bleeding score has a moderate correlation with outcomes in the elderly. Until now, there have not been head-to-head scores that quantify the ischemic versus hemorrhagic risk or scores that use the same end point and timeline (e.g., ischemic death rate versus bleeding death rate at one month). We also recommend that the frailty score be considered or integrated into the current existing scores to better quantify the overall patient risk. With regard to medical treatment, based on the subgroup analysis, we identified the drugs that have the least adverse effects in the elderly while maintaining optimal efficacy.

Diagnostic modalities for the evaluation of anomalous left main coronary arteries

Anomalous coronary arteries are rare and usually identified as an incidental finding during cardiac catheterization. The particular difficulty with cardiac catheterization techniques is not necessarily the presence of the anomalous coronary artery, but its anatomic course. Oftentimes, surgical intervention is necessary once these anomalies are discovered. The identification and anatomic characterization of anomalous coronary arteries has been significantly advanced with the use of current diagnostic noninvasive imaging modalities. We present 3 cases of an anomalous left main coronary artery that arises from the right sinus of Valsalva. Noninvasive imaging methods provided a clear anatomic course of the anomalous vessel.

Correlations Between Fractional Flow Reserve and Intravascular Ultrasound in Patients With an Ambiguous Left Main Coronary Artery Stenosis

Background— Intravascular ultrasound (IVUS) is being used to assess the significance of a left main coronary artery stenosis (LMCS). However, the cutoff values of IVUS parameters at which to predict a fractional flow reserve (FFR) of 0.75 are unknown.

Methods and Results— In 55 patients with an angiographically ambiguous LMCS, a pressure guidewire was used to calculate FFR, and IVUS parameters were calculated after automatic pullback. FFR averaged 0.86±0.13 (range, 0.55 to 1.0). IVUS minimum lumen diameter (MLD), minimum lumen area (MLA), cross-sectional narrowing (CSN), and area stenosis (AS) were 3.8±0.61 mm, 7.65±2.9 mm 2 , 59±13%, and 47±19%, respectively. Regression analysis demonstrated strong correlations between FFR and MLD ( r =0.79, P <0.0001) as well as between FFR and MLA ( r =0.74, P <0.0001). There were inverse, moderate correlations between FFR and CSN ( r =0.69, P <0.0001), followed by those between FFR and AS ( r =0.54, P <0.0001). Compared with FFR as the “gold standard,” an MLD of 2.8 mm had the highest sensitivity and specificity (93% and 98%, respectively) for determining the significance of an LMCS, followed by an MLA of 5.9 mm 2 (93% and 95%, respectively). Based on an FFR <0.75 and an FFR ≥0.75, the 38-month survival and event-free survival estimates (EFSEs) were both 100% and 100% versus 90%, respectively ( P =NS).

Conclusions— We conclude that (1) an IVUS MLD and MLA of 2.8 mm and 5.9 mm 2 , respectively, strongly predict the physiological significance of an LMCS and (2) among patients with an LMCS, an FFR of 0.75 is a strong predictor of survival and EFSE.

Targeted disruption of the matrix metalloproteinase-9 gene impairs smooth muscle cell migration and geometrical arterial remodeling

Matrix remodeling plays an important role in the physiological and pathological remodeling of blood vessels. We specifically investigated the role of matrix metalloproteinase (MMP)-9, an MMP induced during arterial remodeling, by assessing the effects of genetic MMP-9 deficiency on major parameters of arterial remodeling using the mouse carotid artery flow cessation model. Compared with remodeling of matched wild-type (WT) arteries, MMP-9 deficiency decreased intimal hyperplasia, reduced the late lumen loss, eliminated the correlation between intimal hyperplasia and geometric remodeling, and led to significant accumulation of interstitial collagen. Biochemical analysis of MMP-9 knockout (KO) arterial tissue and isolated smooth muscle cells (SMCs) confirmed the lack of MMP-9 expression or compensation by other gelatinases. To investigate potential mechanisms for the in vivo observations, we analyzed in vitro effects of MMP-9 deficiency on the migration, proliferation, and collagen gel contracting capacity of aortic SMCs isolated from MMP-9 KO and WT mice. Although proliferation was comparable, we found that MMP-9-deficient cells had not only decreased migratory activity, but they also had decreased capacity to contract collagen compared with WT cells. Thus, MMP-9 appears to be involved not only in degradation, but also in reorganization of a collagenous matrix, both facets being essential for the outcome of arterial remodeling. Our results also establish MMP-9 as an attractive therapeutic target for limiting the effects of pathological arterial remodeling in restenosis and atherosclerosis.

Expansive arterial remodeling is associated with increased neointimal macrophage foam cell content: the murine model of macrophage-rich carotid artery lesions

BACKGROUND

Recent observations associate plaque instability with expansive arterial remodeling, suggesting a common driving mechanism.

METHODS AND RESULTS

To demonstrate that macrophages, a characteristic of vulnerable plaques, also assist in expansive remodeling, we compared carotid artery remodeling due to formation of experimental macrophage-rich and macrophage-poor lesions in the flow cessation model in hypercholesterolemic apolipoprotein E knockout (ApoE KO) and wild type (WT) mice. After ligation, macrophages started to rapidly accumulate in ApoE KO but not in WT carotid artery lesions. Macrophage-rich ApoE KO intimal lesions grew fast, typically occluding within 14 days, despite a tripling of the vessel area. Outward remodeling of macrophage-rich ApoE KO arteries positively correlated with macrophage area (r2=0.600, P<0.001). To investigate potential mechanisms of macrophage-enabled expansive remodeling, we compared levels of matrix metalloproteinases in homogenates of macrophage-rich and macrophage-poor carotid arteries. Gelatinolytic activity of macrophage-rich lesions increased faster and reached maximal levels several fold higher than in the macrophage-poor WT lesions.

CONCLUSIONS

Our results suggest that macrophages facilitate expansive arterial remodeling through increased matrix degradation by matrix metalloproteinases. This initially favorable remodeling action may eventually increase the vulnerability of macrophage-rich atherosclerotic plaques.

Stable lower PAR expression decreased DU145 prostate cancer cell growth in SCID mice

BACKGROUND

PAR is a novel gene ubiquitously expressed in normal and malignant tissues with a trend towards higher expression in tumor cells. PAR biological function is unknown. Here we report the effect of lowering PAR expression on in vitro and in vivo proliferation of DU145 cells.

METHODS

Decreased PAR expression was achieved by stable transfection of DU145 cells with antisense PAR cDNA cloned in pCMV-Script expression vector. The proliferative potential of DU145 transfectants was studied by cell counts, colony formation in soft agar, flow cytometry, and growth in severe combined immunodeficient (SCID) mice.

RESULTS

DU145 transfectants exhibited a decreased cell proliferation in tissue culture and a low efficiency of colony formation in soft agar. Flow cytometry revealed an arrest of these cells in G2-M phase of mitotic cycle. A dramatic decrease of tumor growth was observed when DU145 transfectant cells were inoculated in SCID mice, compared with controls. Histological examination of these tumors showed a marked decrease in cell density and in number of mitoses while control tumors showed a high cell density and numerous mitoses.

CONCLUSIONS

The data presented here provide the first evidence for PAR gene cellular function and its possible implication in malignant transformation.

Remodeling of carotid artery is associated with increased expression of matrix metalloproteinases in mouse blood flow cessation model

BACKGROUND

The matrix-degrading activity of matrix metalloproteinases (MMPs), required for cell migration and general tissue reshaping, is thought essential for pathological arterial remodeling in atherosclerosis and restenosis.

METHODS AND RESULTS

We triggered remodeling of the carotid artery in C57BL/6 mice by blood flow cessation to study the relationship with gelatinases MMP-9 and MMP-2. Ligated and contralateral carotid arteries from ligated and sham-operated mice were harvested fresh, for biochemical analyses, or were perfusion-fixed, for histological studies, at 0, 1, 3, 7, 14, and 28 days after ligation. An early statistically significant (P:<0.01) 4- to 5-fold increase in MMP-9 expression detected by SDS-PAGE zymography and Western blotting in tissue homogenates of ligated carotid arteries 1 day after flow cessation was maintained through day 7, after which expression gradually fell. Maximal MMP-9 levels were higher than MMP-2 levels, which became significantly increased 7 days after ligation. Proliferating cells, identified by bromodeoxyuridine incorporation, were detectable at day 1 in the adventitia and subsequently throughout the wall. Neointima was visible in 3-day specimens of ligated arteries. Suggested by morphology and predicted by theoretical considerations, maximal MMP-9 expression coincided with cell migration into the neointima, supporting its enabling role. Morphological measurements also demonstrated positive lumen remodeling up to 7 days after ligation.

CONCLUSIONS

MMP-9 induction is associated with the formation of intimal hyperplasia and does not require frank mechanical injury. Our data also show that a significant increase in MMP-9 expression preceded the positive geometrical remodeling of arteries, suggesting a potentially beneficial role for this matrix-degrading enzyme.

PAR, a novel androgen regulated gene, ubiquitously expressed in normal and malignant cells

During our work on the mechanism of hormone resistance of prostatic carcinomas, a novel gene that we called PAR (prostate androgen regulated) was isolated from an androgen resistant subline (LNCaP-OM) using a modified representational difference analysis. The complete sequence of the gene cDNA has 1029 nucleotides with a continuous reading frame of 438 bases encoding for 146 amino acids. Its deduced amino acid sequence has motifs for myristoylation and phosphorylation by protein kinase C. The PAR gene was overexpressed in all prostatic carcinoma cell lines studied (LNCaP, DU145, PC3 and LNCaP-OM) compared to the normal prostatic tissue. Furthermore, its expression was higher in androgen resistant prostate cancer lines DU145, PC3 and LNCaP-OM, in comparison to androgen sensitive LNCaP cells. The expression of this gene was down regulated by androgens in androgen sensitive prostate cells, but not in the hormone resistant cell lines. The PAR mRNA was detected in all 29 normal human tissues studied and overexpressed in most (67%) of their malignant counterparts. The PAR expression was higher in MCF7 and T47D breast cancer cell lines, as well as in all primary breast tumors studied compared to their normal tissue counterparts. The biological function of this gene is still unknown, but its ubiquitous expression in normal tissues and its overexpression in some malignancies suggest the PAR involvement in certain basic cellular processes and possibly, in malignant transformation.

Placental transfer of etozolin and ozolinone during the first half of gestation in man

The placental transfer of etozolin and its pharmacologically active metabolite ozolinone was studied in 48 patients during the first (44 patients) and second (4 patients) trimester. 24 patients received a single oral dose of etozolin 400 mg 2-20 h prior to interruption of pregnancy by curettage or prostaglandin infusion. 24 other patients received 3 oral doses of etozolin 400 mg (11 patients) or 800 mg (13 patients) on 3 consecutive days, and pregnancy was terminated 2-10 h after the last dose. The fetal tissue/maternal serum and placental tissue/maternal serum ratios of etozolin and ozolinone were found to lie between 0.3 and 0.6. The serum levels were lower in pregnant than in non-pregnant patients. The low placental and fetal concentrations of etozolin and ozolinone suggest that these drugs may prove useful when a diuretic is indicated in the treatment of oedema and hypertension during pregnancy.