Prenatal diagnosis of trisomy 13 on fetal cells obtained from maternal blood after minor enrichment

In a pilot study to establish fetal nucleated red blood cell (NRBC) detection in maternal blood, trisomy 13 was diagnosed by FISH analysis at 11 weeks' gestation. The NRBCs were detected after a single-step ficoll density gradient enrichment. In blood samples taken both before and after CVS, 52 and 80 NRBCs, respectively, were found to be positive for fetal haemoglobin. In 47 per cent of these cells, FISH analysis for X and Y chromosomes confirmed the fetal sex. Moreover, 48 per cent of these NRBCs showed three fluorescent signals for a chromosome 13 probe, which confirmed the diagnosis of trisomy 13, previously detected at CVS karyotyping. This is the first report of non-invasive prenatal diagnosis of trisomy 13, i.e., pre-CVS, in the first trimester. The high number of fetal NRBCs detected indicates a connection with aneuploidy, probably due to early impairment of the feto-maternal barrier.     

Peripheral O2 diffusion does not affect V(O2)on-kinetics in isolated insitu canine muscle

To test the hypothesis that muscle O2 uptake (V(O2)) on-kinetics is limited, at least in part, by peripheral O2 diffusion, we determined the V(O2) on-kinetics in 1) normoxia (Control); 2) hyperoxic gas breathing (Hyperoxia); and 3) hyperoxia and the administration of a drug (RSR-13, Allos Therapeutics), which right-shifts the Hb-O2 dissociation curve (Hyperoxia+RSR-13). The study was conducted in isolated canine gastrocnemius muscles (n = 5) during transitions from rest to 3 min of electrically stimulated isometric tetanic contractions (200-ms trains, 50 Hz; 1 contraction/2 s; 60-70% peak V(O2)). In all conditions, before and during contractions, muscle was pump perfused with constantly elevated blood flow (Q), at a level measured at steady state during contractions in preliminary trials with spontaneous Q x Adenosine was infused intra-arterially to prevent inordinate pressure increases with the elevated Q x Q was measured continuously, arterial and popliteal venous O2 concentrations were determined at rest and at 5- to 7-s intervals during contractions, and V(O2) was calculated as Q x arteriovenous O2 content difference. PO2 at 50% HbO2 saturation (P50) was calculated. Mean capillary PO2 (Pc(O2)) was estimated by numerical integration. P50 was higher in Hyperoxia+RSR-13 [40 +/- 1 (SE) Torr] than in Control and in Hyperoxia (31 +/- 1 Torr). After 15 s of contractions, Pc(O2) was higher in Hyperoxia (97 +/- 9 Torr) vs. Control (53 +/- 3 Torr) and in Hyperoxia+RSR-13 (197 +/- 39 Torr) vs. Hyperoxia. The time to reach 63% of the difference between baseline and steady-state V(O2) during contractions was 24.7 +/- 2.7 s in Control, 26.3 +/- 0.8 s in Hyperoxia, and 24.7 +/- 1.1 s in Hyperoxia+RSR-13 (not significant). Enhancement of peripheral O2 diffusion (obtained by increased PcO2 at constant O2 delivery) during the rest-to-contraction (60-70% of peak V(O2)) transition did not affect muscle V(O2) on- kinetics.     

Psychosocial characteristics of pregnant and nonpregnant HIV-seropositive women

Thirty-three HIV-positive women, 12 of whom were pregnant, participated in semistructured interviews to define areas of psychosocial need. Eighty-eight percent of the subjects reported current unemployment. A history of substance abuse was reported by 82 percent, suicide attempts by 52 percent, and sexual problems by 43 percent. Approximately 30 percent reported elevated levels of depressive symptoms on standardized symptom inventories. The pregnant women appeared psychologically healthier than the nonpregnant group. HIV-positive women face multiple psychosocial stressors and may experience significant psychological distress.     

Cathepsin L2, a novel human cysteine proteinase produced by breast and colorectal carcinomas

We have identified and cloned a new member of the papain family of cysteine proteinases from a human brain cDNA library. The isolated cDNA codes for a polypeptide of 334 amino acids that exhibits all of the structural features characteristic of cysteine proteinases, including the active site cysteine residue essential for peptide hydrolysis. Pairwise comparisons of this amino acid sequence with the remaining human cysteine proteinases identified to date showed a high percentage of identity (78%) with cathepsin L; the percentage of identity with all other members of the family was much lower (<40%). On the basis of these structural characteristics, we have tentatively called this novel protein cathepsin L2. The cDNA encoding the mature cathepsin L2 was expressed in Escherichia coli, and after purification, the recombinant protein was able to degrade the synthetic peptide benzyloxycarbonyl-L-phenylalanyl-L-arginine-7-amido-4-methylcoumarin, which is commonly used as a substrate for cysteine proteinases. Cathepsin L2 proteolytic activity on this substrate was abolished by trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane, an inhibitor of cysteine proteinases, thus providing additional evidence that the isolated cDNA encodes a functional cysteine proteinase. Northern blot analysis of polyadenylated RNAs isolated from a variety of human tissues demonstrated that cathepsin L2 is predominantly expressed in the thymus and testis. This finding is in marked contrast with the wide tissue distribution of most cysteine proteinases characterized to date, including cathepsin L, and suggests that cathepsin L2 may play a specialized role in the thymus and testis. Expression analysis of cathepsin L2 in human tumors revealed a widespread expression in colorectal and breast carcinomas but not in normal colon or mammary gland or in peritumoral tissues. Cathepsin L2 was also expressed by colorectal and breast cancer cell lines as well as by some tumors of diverse origin, including ovarian and renal carcinomas. These results open the possibility that this novel enzyme may be involved in tumor processes, as already reported for other cysteine proteinases, including cathepsin L.     

Discovery of a novel tetrahydroacridine acetylcholinesterase inhibitor through an indexed combinatorial library

BACKGROUND: Methods for the rapid and efficient preparation of drug candidates through combinatorial chemistry are of increasing interest. We have previously reported an indexed combinatorial library method that allows both the preparation and testing of compounds in solution. We set out to apply this method to develop more effective analogs of the known, marketed drug tacrine, an acetylcholinesterase inhibitor. RESULTS: A one-step condensation of cyclohexanones with cyanoanilines to generate tetrahydroacridine pools was developed. The resulting library of (formally) 72 tetrahydroacridines was screened against acetylcholinesterase, and a compound 10-fold more potent than tacrine, 7-nitrotacrine, was discovered. Its increased potency could be readily explained by examining the known structure of the complex of acetylcholinesterase with tetrahydroacridine. CONCLUSIONS: In this work, we have provided a relatively rare example of carbon-carbon bond formation in a pool synthesis and have discovered a potentially useful acetylcholinesterase inhibitor.     

Three-year outcome after balloon aortic valvuloplasty. Insights into prognosis of valvular aortic stenosis

BACKGROUND: To identify predictors of long-term outcome after balloon aortic valvuloplasty, we analyzed data on 674 adults (mean age, 78 +/- 9 years; 56% were women) undergoing this procedure at 24 clinical centers who had a mean initial increase in aortic valve area of 0.3 cm2. METHODS AND RESULTS: Baseline data included clinical, echocardiographic, and catheterization variables. Follow-up data included mortality, cause of death, rehospitalization, 6-month echocardiography, and functional status. Kaplan-Meier curves and log-rank tests were used to evaluate survival in subgroups. Multivariate Cox regression models were used to identify independent predictors of survival. Overall survival was 55% at 1 year, 35% at 2 years, and 23% at 3 years, with the majority of deaths (70%) classified as cardiac by an independent review committee. Rehospitalization was common (64%), although 61% of survivors at 2 years reported improved symptoms. Echocardiography at 6 months (n = 115) showed restenosis from the postprocedural valve area of 0.78 +/- 0.31 cm2 to 0.65 +/- 0.25 cm2 (P < .0001). With stepwise multivariate analysis, sequentially adding clinical, echocardiographic, and catheterization variables, the overall model identified independent predictors of survival as baseline functional status, baseline cardiac output, renal function, cachexia, female gender, left ventricular systolic function, and mitral regurgitation. Baseline and postprocedural variables were examined to identify which subgroup of patients has the best outcome after aortic valvuloplasty. A "lower-risk" subgroup (28% of the study population), defined by normal left ventricular systolic function and mild clinical functional limitation, had a 3-year survival of 36% compared with 17% in the remainder of the study group. CONCLUSIONS: Long-term survival after balloon aortic valvuloplasty is poor with 1- and 3-year survival rates of 55% and 23%, respectively. Although survivors report fewer symptoms, early restenosis and recurrent hospitalization are common.     

Conserved sequence motifs among bacterial, eukaryotic, and archaeal phosphatases that define a new phosphohydrolase superfamily

Members of a new molecular family of bacterial nonspecific acid phosphatases (NSAPs), indicated as class C, were found to share significant sequence similarities to bacterial class B NSAPs and to some plant acid phosphatases, representing the first example of a family of bacterial NSAPs that has a relatively close eukaryotic counterpart. Despite the lack of an overall similarity, conserved sequence motifs were also identified among the above enzyme families (class B and class C bacterial NSAPs, and related plant phosphatases) and several other families of phosphohydrolases, including bacterial phosphoglycolate phosphatases, histidinol-phosphatase domains of the bacterial bifunctional enzymes imidazole-glycerolphosphate dehydratases, and bacterial, eukaryotic, and archaeal phosphoserine phosphatases and threalose-6-phosphatases. These conserved motifs are clustered within two domains, separated by a variable spacer region, according to the pattern [FILMAVT]-D-[ILFRMVY]-D-[GSNDE]-[TV]-[ILVAM]-[AT S VILMC]-X-?YFWHKR)-X-?YFWHNQ?-X( 102,191)-?KRHNQ?-G-D-?FYWHILVMC?-?QNH?-?FWYGP?-D -?PSNQYW?. The dephosphorylating activity common to all these proteins supports the definition of this phosphatase motif and the inclusion of these enzymes into a superfamily of phosphohydrolases that we propose to indicate as "DDDD" after the presence of the four invariant aspartate residues. Database searches retrieved various hypothetical proteins of unknown function containing this or similar motifs, for which a phosphohydrolase activity could be hypothesized.     

Fungal endocarditis following cardiac surgery

This study examines the long-term prognosis of patients with an abnormal exercise radionuclide angiogram in the absence of significant angiographic coronary artery disease (CAD). In general, patients without significant CAD have an excellent prognosis, but the long-term outcome for the subset of patients with an "ischemic" exercise test is not known. In this study, 161 patients with normal coronary arteries or insignificant CAD (< 50% left main and < 70% left anterior descending, left circumflex, or right), resting left ventricular (LV) ejection fraction > or = 0.50, and an abnormal exercise radionuclide angiogram (LV ejection fraction that decreased with exercise or peak exercise LV ejection fraction < 0.60) were followed for a median duration of 11.3 years. The mean delta LV ejection fraction was -0.07, 98 patients (61%) had a decrease in LV ejection fraction of > or = 5 units, and 40 patients (25%) had peak exercise LV ejection fraction < 0.50. During follow-up there were 19 deaths (only 1 of which was cardiac), 7 nonfatal myocardial infarctions, and 9 revascularization procedures. At 12 years, overall survival was 88%, better than the expected survival for the age- and sex-matched general population. Survival free of cardiac death or myocardial infarction was 94% and survival free of any cardiac event including revascularization was 88%. Thus, patients with an abnormal exercise radionuclide angiogram but without significant CAD have an excellent long-term prognosis.