Elevated concentrations of eotaxin and interleukin-5 in human neurocysticercosis

Symptomatic neurocysticercosis, a major cause of epilepsy worldwide, results from inflammation around Taenia solium larvae, but the mechanisms are unknown. Eotaxin, not previously reported in cases of human infection, and interleukin-5 (IL-5) but not IL-8 concentrations were elevated in patient serum, and IL-5 levels were also elevated in cerebrospinal fluid (CSF). Eosinophil-selective mediators may be involved in the pathogenesis of cysticercosis. IL-6 concentrations were also elevated in patient CSF, possibly indicative of an acute-phase response.     

Interfacial communications in recombinant rabbit kidney pyruvate kinase

Tissue-specific isozymes of pyruvate kinase are particularly attractive systems to elucidate the molecular mechanism(s) of conferring allostery. The muscle- and kidney-type isozymes are coded by the same gene. As a consequence of alternative message RNA splicing, the two primary sequences differ by a small number of residues. However, they exhibit very different regulatory behavior. In an effort to identify the roles of specific residues in conferring allostery, the gene encoding rabbit kidney-type pyruvate kinase was cloned and expressed in Escherichia coli. The primary structure of recombinant rabbit kidney-type pyruvate kinase (rRKPK) and recombinant rabbit muscle-type pyruvate kinase (rRMPK) differ at 22 positions, which are located in a region that forms important intersubunit contacts in the RMPK structure. Velocity sedimentation and analytical gel chromatographic studies show that rRKPK undergoes reversible dimer left and right arrow tetramer assembly with an equilibrium constant of 28 +/- 3 mL/mg. This subunit assembly process provides the opportunity to elucidate the role of this dimer interface in transmission of signal upon binding of substrates and allosteric effectors. The assembly to tetrameric rRKPK is favored by the binding of phosphoenolpyruvate (PEP), one of the two substrates, or fructose 1,6-bisphosphate (FBP), an activator. In contrast, the equilibrium is shifted toward dimeric rRKPK upon binding of adenosine diphosphate (ADP), the other substrate, or l-phenylalanine (Phe), the inhibitor. These observations provide significant new insights to the molecular mechanism of allosteric regulation in the pyruvate kinase system. First, all substrates and effectors communicate through this particular dimer-dimer interface. Second, the thermodynamic signatures of these communications are qualitatively different for the two substrates and between the activator, FBP, and inhibitor, Phe.     

Targeted therapy of human malignant glioma in a mouse model by 2-5A antisense directed against telomerase RNA

Telomerase is the RNA-protein complex which elongates telomeric DNA (TTAGGG)n and appears to play an important role in cellular immortalization. The almost exclusive expression of telomerase in tumor cells, and not in most normal cells, offers an exciting opportunity for therapy by inhibiting its function. Here, we have investigated the effect of inhibition of telomerase on the growth and survival of human malignant glioma cells in vitro and in vivo by using a 19-mer antisense oligonucleotide against human telomerase RNA linked to a 2',5'-oligoadenylate (2-5A). 2-5A antisense functions by activating the endoribonuclease, RNase L, resulting in the degradation of single stranded, targeted RNA. We have shown that the 2-5A antisense treatment effectively suppressed tumor cell growth and survival in vitro. Furthermore, treatment of tumors grown in nude mice with the antisense oligonucleotide inhibited survival of the tumor cells. TUNEL assays suggest that this effect is mediated through the induction of apoptosis. Targeting telomerase RNA with 2-5A antisense, therefore, may represent an effective and novel approach for treatment of a broad range of cancers.     

The clinical spectrum of post-streptococcal syndromes with arthritis in children

Acute rheumatic fever (ARF) and post-streptococcal reactive arthritis (PSRA) are well known complications of streptococcal throat infections. We describe four children with arthritis following a streptococcal throat infection. In addition to arthritis, other clinical manifestations included erythema nodosum, livedo reticularis and cutaneous vasculitis. Because of the very diverse clinical manifestations that may appear after a streptococcal throat infection, we suggest a classification and treatment of post-streptococcal syndromes according to the severity of the disease.     

Positron emission tomographic analysis of central dopamine D1 receptor binding in normal subjects treated with the atypical neuroleptic, SDZ MAR 327

Three in vitro assays (the isotopic semimicrotest [700 microl per well; 24-well plates], the isotopic microtest [200 microl per well; 96-well plates], and the rapid in vitro test) and the standard in vivo test for chloroquine resistance were compared for 99 clinical isolates of Plasmodium falciparum obtained from symptomatic African patients. The 50% inhibitory concentrations determined by the two isotopic tests were similar and were highly correlated (r = 0.965; P < 0.05), showing a high concordance between the semimicrotest and the microtest. There was a moderate agreement between these two isotopic tests and the in vivo test. Most of the discordant results were probably due to host factors, including reinfections, pharmacokinetic variations, and immunologic response, which are eliminated in in vitro assays. The rapid in vitro test based on the inhibition of chloroquine efflux in the presence of verapamil was poorly concordant with the other tests. Despite some discordant results, isotopic in vitro assays are useful to characterize the phenotypes of individual isolates without the interference of host factors and are complementary to in vivo evaluation of drug efficacy. However, in vitro assays need to be standardized to allow direct comparison of results between different laboratories.     

The labrum of the calcaneocuboid joint

Linkage of a neurophysiological deficit associated with schizophrenia, i.e., the failure to inhibit the auditory P50 response, was previously reported at chromosome 15q14. The marker with the highest pairwise lod score, D15S1360, was isolated from a yeast artificial chromosome containing a candidate gene, the alpha7-nicotinic acetylcholine receptor gene. In the present study, this linkage was further investigated in a subset of the NIMH Genetics Initiative schizophrenia families. These families have not been studied neurophysiologically, as were the families in the original report. Therefore, the DSMIII-R diagnosis of schizophrenia was used as the affected phenotype. Twenty families fulfilled the criteria of at least one sibpair concordant for schizophrenia, along with their two parents or another affected relative outside the nuclear family, available for genotyping. Sibpair analysis showed a significant proportion of D15S1360 alleles shared identical-by-descent (0.58; P < 0.0024). The results further support the involvement of this chromosomal locus in the genetic transmission of schizophrenia.     

Development of suprathreshold word recognition test for Russian-speaking patients

BACKGROUND: Gallstone disease is a major source of morbidity in the United States. Gallstones are twice as common in women as in men, but severe biliary events leading to surgery occur with equal frequency in the two sexes. OBJECTIVE: To determine whether physical activity decreases risk for symptomatic gallstone disease in men. DESIGN: Prospective cohort study. SETTING: U.S. male health professionals. PATIENTS: 45,813 men 40 to 75 years of age were followed from 1986 to 1994. MEASUREMENTS: Questionnaires mailed in 1986, 1988, 1990, 1992, and 1994 asked about physical activity, incidence of gallstone disease, age, body weight, dietary and alcohol intake, smoking habits, use of medications, and occurrence of diagnosed medical conditions other than gallstone disease. RESULTS: 828 men reported having newly symptomatic gallstones (diagnosed by ultrasonography or radiography) or undergoing cholecystectomy for recent symptoms. After adjustment for multiple confounders, increased physical activity was inversely related to risk for symptomatic gallstone disease. When extreme quintiles were compared, men younger than 65 years of age had a stronger inverse association (multivariate relative risk, 0.58 [95% CI, 0.44 to 0.78]) with risk than did men 65 years of age or older (relative risk, 0.75 [CI, 0.52 to 1.09]). In contrast, sedentary behavior was positively related to risk for symptomatic gallstone disease. Men who watched television more than 40 hours per week had a higher risk for symptomatic gallstones than men who watched less than 6 hours per week (relative risk for older men, 3.32 [CI, 1.51 to 7.27]; relative risk for younger men, 1.58 [CI, 0.38 to 6.48]). CONCLUSIONS: Physical activity may play an important role in the prevention of symptomatic gallstone disease in men even beyond its benefit for control of body weight. The results of this study indicate that 34% of cases of symptomatic gallstone disease in men could be prevented by increasing exercise to 30 minutes of endurance-type training five times per week.     

Malignant adenomyoepithelioma of the breast with mixed osteogenic, spindle cell, and carcinomatous differentiation

Antenatal echocardiographic diagnosis of congenital heart disease in 699 women living in the department of the C?te d'Or between 1988 and 1996 revealed 39 cardiac abnormalities which were later confirmed by anatomical examination or echocardiography. During the same period, 157 cardiac malformations which could have been detected in the antenatal period were diagnosed after birth. The detection rate of congenital heart disease was 19.8% over the whole study period, and 33.3% in the last three years. The malformations which were most easily diagnosed were hypoplastic left ventricle, single ventricle, atriventricular canal and severe obstruction of the ventricular outflow tracts. Twenty-one abortions (53.8%) were undertaken because of the severity of the cardiac lesion or of a genetic abnormality. Seventeen children were live born (43.5%) but, globally, they had severe malformations and the mortality rate was 84.5% whereas in the children diagnosed post-partum, the lesions were generally less severe and the mortality was 19.7%. The detection rate of congenital heart disease depends on the screening of first intention. Thus, 90% of the lesions diagnosed in this series were referred because of a foetal heart abnormality and, in this indication, echographic expertise was by far the most accurate with 33% of confirmation. As other workers have reported, teaching programmes and regional collaboration between physicians implicated in antenatal care are essential.     

Neural tube and craniofacial defects with special emphasis on folate pathway genes

Neural tube and orofacial defects are common congenital malformations in humans. While etiologically heterogeneous, they are for the most part multifactorial in their pathogenesis, having both genetic and environmental components in their development. In recent years, there has been a great deal of epidemiologic evidence demonstrating that women who received multivitamins containing folic acid periconceptionally had significantly reduced occurrence and recurrence risks for producing infants with such malformations. This risk reduction is not observed in all populations, further suggestive of a genetic regulation of this phenomenon. Unfortunately, the mechanisms underlying the beneficial effects of folic acid are not well-understood. In this article, we review the relevant epidemiologic data on both neural tube defects and orofacial malformations, the fundamental embryological processes involved in closing the neural tube, and the development of the craniofacies, and propose a working hypothesis for susceptibility to these malformations. This hypothesis is based on the interworkings of cellular folate transport, focusing on the key elements involved in potocytosis. We propose that infants with mutations in the folate receptor alpha gene might be at increased risk for congenital anomalies due to a reduced binding affinity for 5-methyltetrahydrofolate, the physiologic form of folic acid. Various experimental approaches to test the working hypothesis are considered.     

Fas-mediated apoptosis in mouse hepatocytes involves the processing and activation of caspases

The mechanism of Fas antigen-induced hepatocyte apoptosis was investigated. Using a monoclonal antibody directed against the Fas antigen, apoptosis was induced in freshly isolated murine hepatocytes within 90 minutes of antibody addition as assessed by plasma membrane bleb formation, chromatin condensation, and DNA fragmentation. Pretreatment of the cells with the caspase inhibitors, N-acetyl-Asp-Glu-Val-Asp aldehyde (Ac-DEVD-CHO), benzyloxycarbonyl-Val-Ala-DL-Asp-fluoromethylketone (Z-VAD-FMK), or Z-Asp-2,6-dichlorobenzoyloxymethylketone inhibited anti-Fas-mediated apoptosis. Likewise, the serine protease inhibitors, N-tosyl-L-phenyl chloromethyl ketone (TPCK) and 3,4-dichloroisocoumarin (DCI), prevented apoptosis, whereas N-tosyl-L-lysine chloromethyl ketone (TLCK), Ac-Leu-Leu-L-norleucinal, Ac-Leu-Leu-L-methional, and trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane were without effect. Examination of CED-3/caspase-3-related caspases revealed that pro-caspases-3 (CPP32) and -7 (Mch-3alpha) were rapidly processed after Fas antigen stimulation. Caspase-7 was further cleaved to form the catalytically active subunits. In contrast, the p17 subunit of caspase-3 was not detected, indicating slow formation or rapid degradation. The activation of CED-3-related caspases was further confirmed by an increase in the rate of Z-DEVD-7-amino-4-trifluoromethylcoumarin (Z-DEVD-AFC) hydrolysis that was sensitive to Ac-DEVD-CHO and was inhibited by pretreatment of the cells with TPCK but not by DCI. In contrast, no increase in the rates of hydrolysis of Z-YVAD-AFC, a substrate for caspase-1, was detected. Investigation of the in situ proteolytic cleavage of the CED-3 related caspases substrate, poly(ADP-ribose) polymerase, revealed that this protein was not degraded in hepatocytes undergoing Fas-mediated apoptosis. Taken together, our results show that processing of caspases, in particular, caspases-7 and -3, occurs during Fas-induced apoptosis of mouse hepatocytes and suggest a role of these proteases as well as serine protease(s) in the apoptotic response.