Intense-Field Double Detachment of Electrostatically Bound F(-)(NF3)n Cluster Anions.

The interaction of intense laser pulses with size-selected F(-)(NF3)n clusters is experimentally studied. Intense-field double- and multiple-detachment processes in the isolated atomic F(-) anion and in electrostatically bound F(-)(NF3) dimer and F(-)(NF3)2 trimer systems are directly compared. Both dimer and trimer systems are found to exhibit similar enhancement of the highly nonlinear processes, with respect to the atomic system, as reflected in significantly lower saturation intensities. The dependencies of different product channels as a function of laser peak intensity, polarization ellipticity, and laser pulse shape are presented, indicating an efficient nonrescattering mechanism.

Schizophrenia and hallucinogen persisting perception disorder: A clinical investigation.

BACKGROUND AND OBJECTIVES: We compared characteristics of schizophrenia patients with prior LSD use who developed hallucinogen persisting perception disorder (SCH+HPPD) with those who did not (SCH-HPPD). METHODS: Data were collected for 37 subjects in the SCH+HPPD group and 43 subjects in the SCH-HPPD group. RESULTS: Socio-demographics and positive symptom scores were similar between groups. Individuals in the SCHIZO+HPPD group scored lower on general psychopathology and negative symptoms scores. DISCUSSION AND CONCLUSIONS: Individuals with schizophrenia and HPPD present with less severe psychopathology, despite persistent perceptual disturbances. SCIENTIFIC SIGNIFICANCE: Our findings highlight the importance of further research into this subset of patients.

[Polyoxidonium in the treatment of calculous pyelonephritis].

Efficacy of polyoxidonium was studied in combined therapy of urolithiasis complicated with secondary pyelonephritis. Of 60 patients with secondary pyelonephritis in urolithiasis, 30 received adjuvant polyoxidonium. Phospholipids and cholesterol in cytomembranes were defined with thin-layer chromatography. Humoral immunity was evaluated by the levels of IgA, IgM, IgG, hemolytic activity of the compliment system, the level of circulating immune complexes, activity of lysozyme. Concentrations of IL-1beta, TNF, IL-4, IL-6 were also estimated. Subpopulations of immunocompetent cells were tested on flow cytofluorimeter by immunofluorescence with monoclonal antibodies. Phagocytic component of the immune system was assessed by phagocytic activity of neutrophils, phagocytic count, NBT test. The trial demonstrates that polyoxidonium has a positive action on the disease course, an antiinflammatory, immunomodulating properties, suppresses peroxidation, promotes recovery of structural-functional characteristics of cellular membranes in patients with urolithiasis and secondary pyelonephritis. Polyoxidonium is recommended in secondary pyelonephritis and urolithiasis as adjuvant to basic therapy for anti-inflammatory, detoxication and immunomodulating effect.

Impact of total body water errors on Kt/V estimates in children on peritoneal dialysis.

Determining Kt/V in peritoneal dialysis (PD) requires estimation of total body water (TBW). The Dialysis Outcomes Quality Initiative (DOQI) guidelines recommend use of the Mellits and Cheek (MC) formulas for the estimation of TBW in children. However, the MC formulas were developed from healthy children and may not apply to children on PD. Re-evaluating the MC data with additional, recent data from healthy infants has led to the development of new formulas. In addition, and as part of a prospective study of children initiating PD, the Pediatric Peritoneal Dialysis Study Consortium (PPDSC) has directly measured TBW using H2[18O]. To assess the impact of various TBW estimates, KPDt/V values prospectively collected in 24 children were calculated using H2[18O]-measured TBW (O18), MC-derived TBW (MCD), and new-formula TBW (NEW). The mean weekly KPDt/V by O18 was 2.2; by MCD, it was 2.0; and by NEW, it was 2.0. The results derived using the O18 method varied from both the MCD and the NEW results (p < 0.001). The mean deviation from the measured KPDt/V using O18 was 9.5% (maximum: 16%) using the MCD estimate and 7.8% (maximum: 18%) using the NEW formulas. Determinations of KPDt/V are significantly affected by the method of estimating TBW. The PPDSC formulas for children on PD based on the use of H2[18O] offer the most accurate means of calculating TBW and should replace formulas derived from healthy children. The use of Kt/V itself as a marker of adequacy in children will be validated only in prospective studies.

The use of mycophenolate mofetil suspension in pediatric renal allograft recipients.

Mycophenolate mofetil (MMF) is widely used to prevent acute rejection in adults after renal, cardiac, and liver transplantation. This study investigated the safety, tolerability, and pharmacokinetics of MMF suspension in pediatric renal allograft recipients. One hundred renal allograft recipients were enrolled into three age groups (33 patients, 3 months to <6 years; 34 patients, 6 to <12 years; 33 patients, 12 to 18 years). Patients received MMF 600 mg/m2 b.i.d. concomitantly with cyclosporine and corticosteroids with or without antilymphocyte antibody induction. One year after transplantation, patient and graft survival (including death) were 98% and 93%, respectively. Twenty-five patients (25%) experienced a biopsy-proven (Banff grade borderline or higher) or presumptive acute rejection within the first 6 months post-transplantation. Analysis of pharmacokinetic parameters for mycophenolic acid (MPA) and mycophenolic acid glucuronide showed no clinically significant differences among the age groups. The dosing regimen of MMF 600 mg/m2 b.i.d. achieved the targeted early post-transplantation MPA 12-h area under concentration-time curve (AUC0-12) of 27.2 microg h per ml. Adverse events had similar frequencies among the age groups (with the exception of diarrhea, leukopenia, sepsis, and anemia, which were more frequent in the <6 years age group) and led to withdrawal of MMF in about 10% of patients. Administration of MMF 600 mg/m2 b.i.d. is effective in prevention of acute rejection, provides predictable pharmacokinetics, and is associated with an acceptable safety profile in pediatric renal transplant recipients.

Laryngeal penetration: a predictor of aspiration in infants?

BACKGROUND: We routinely observed "isolated" laryngeal penetration (ILP) on upper GI studies in infants with no risk for aspiration. OBJECTIVE: To determine whether "isolated" LP (LP during the pharyngeal phase of swallowing) is a benign process in infants and therefore not a predictor of aspiration as it is known to be in adults. PATIENTS AND METHODS: Two radiologists retrospectively reviewed videotaped upper GI studies done over a 2-year period on patients less than 2 years of age. A total of 110 studies was reviewed, which produced a study group of 34 patients who had no history or clinical suspicion for swallowing dysfunction. RESULTS: Of the 34 patients in the group, 33 demonstrated ILP without radiographic or clinical evidence of aspiration. CONCLUSION: ILP is a benign, normal process in infants likely due to immaturity of the swallowing mechanism. It is not a reliable predictor of aspiration as it is in adults.

Chronic dialysis in children and adolescents. The 1996 annual report of the North American Pediatric Renal Transplant Cooperative Study.

The 1996 annual report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) summarizes data submitted from 130 centers on 2,208 patients in whom 2,787 independent courses of dialysis were performed between 1 January 1992 and 16 January 1996. Approximately two-thirds of the dialysis population were maintained on peritoneal dialysis (PD), with automated PD remaining the preferred modality. There were 964 episodes of peritonitis in 1,018 patient years, yielding an overall peritonitis rate of 1 episode every 13 patient months. More PD patients attended school full time than hemodialysis (HD) patients at baseline (77% vs. 45%), which continued at 6, 12, and 24 months of followup. There were fewer Hispanic patients who were full-time students, whether on HD or PD, compared with white or black patients; 18% of Hispanic patients did not attend school, even though they were medically capable. The majority of dialysis courses terminated due to transplantation (54%), with change in dialysis modality the next most-common reason (28%). Early dialysis termination for any reason was seen more often in HD than PD (40% vs. 23% at 6 months), but by 24 months similar percentages of PD and HD courses had been terminated (75% HD, 72% PD). The most-common PD access was a Tenckhoff catheter with a single cuff, a straight tunnel and lateral exit site. The majority of HD accesses were external percutaneous catheters, with the sublcavian vein the most-common site. Erythropoietin was administered in 93% of HD and PD patients at 24 months.

Analysis of select folate pathway genes, PAX3, and human T in a Midwestern neural tube defect population.

Neural tube defects (NTDs) are a common birth defect, seen in approximately 1/1,000 births in the United States. NTDs are considered a complex trait where several genes, interacting with environmental factors, create the phenotype. Using a Midwestern NTD population consisting of probands, parents, and siblings from Iowa, Minnesota, and Nebraska, we analyzed a range of candidate genes, including 5,10-methylenetetrahydrofolate reductase (MTHFR), folate receptors-alpha (FOLR1; hereafter abbreviated "FR-alpha") and -beta (FOLR2; hereafter, "FR-beta"), methionine synthase (hereinafter, "MS"), T, the human homolog of the murine Brachyury gene, and the paired-box homeotic gene 3 (PAX3), for association with NTDs. We were unable to demonstrate an association using a previously described Ala-->Val mutation in MTHFR and the majority of our NTD populations. However, we discovered a silent polymorphism in exon 6 of MTHFR which conserved a serine residue and which showed significant association with NTDs in our Iowa population. Analysis of exon 7 of MTHFR then demonstrated an Ala-->Glu mutation which was significantly associated with our Iowa NTD population; however, we could not replicate this result either in a combined Minnesota/ Nebraska or in a California NTD population. Using polymorphic markers for MS, FR-beta, T, and PAX3, we were unable to demonstrate linkage disequilibrium with our NTD populations. A mutation search of FR-alpha revealed one proband with a de novo silent mutation of the stop codon. This work provides a new panel of genetic variants for studies of folate metabolism and supports, in some NTD populations, an association between MTHFR and NTDs.

Serum concentration of calcium, 1,25 vitamin D and parathyroid hormone are not correlated with coronary calcifications. An electron beam computed tomography study.

BACKGROUND: The amount of coronary artery calcification, measured using electron beam computed tomography, is correlated with the volume of coronary artery atherosclerotic plaque, the severity of stenosis by angiography, and with the likelihood of future cardiovascular events. The deposition of calcium in atherosclerotic plaques may also be influenced by determinants of calcium metabolism, thus contributing to the variance of the relation between coronary artery calcification and extent of atherosclerosis. Our objective was to determine whether this variance could be explained by differences in the parameters of calcium metabolism. DESIGN AND METHODS: We measured serum concentrations of calcium, 1,25(OH)2 vitamin D and parathyroid hormone (PTH) in 50 subjects undergoing angiography for clinical indications, and evaluated the correlations between these concentrations and calcium deposition in the coronary arteries, and the ratio of calcium deposition to extent of atherosclerosis using coronary angiography. RESULTS AND CONCLUSIONS: Serum concentrations of calcium 1,25(OH)2 vitamin D and PTH were not correlated with coronary calcification or the ratio of coronary calcification to the extent of coronary stenosis. We conclude that, in subjects undergoing coronary angiography, the variance of the relationship between coronary atherosclerosis and coronary calcium is not a result of differences in serum concentrations of calcium, 1,25(OH)2 vitamin D or PTH.

Nocturnal polysomnography in obsessive-compulsive disorder.

To determine if sleep abnormalities occur in obsessive-compulsive disorder (OCD), 2 nights of sleep electroencephalographic (EEG) recordings were obtained from 13 medication-free outpatients with OCD and 13 age- and sex-matched normal volunteers. Patients were awake more on night 2 than on night 1, whereas control subjects had less time awake on night 1; no other differences between groups were found on sleep latency, sleep time, minutes of movement, sleep efficiency, rapid eye movement (REM) latency or amount of stage 1, 2, 3, or 4 or REM sleep. Within the patient group, total scores on the Yale-Brown Obsessive-Compulsive Scale were negatively correlated with total sleep time (r = -0.51, P = 0.07), sleep efficiency (r = -0.51, P= 0.07), and duration of stage 1 + 2 sleep (r = - 0.49, P = 0.09) but not with REM time (r = - 0.05, P = 0.87) or latency (r = -0.26, P = 0.39). Previous sleep studies in OCD have had divergent results, especially regarding REM latency; our results suggest that many OCD patients have essentially normal sleep EEG findings.

Comparison of electron beam computed tomography scanning and conventional risk factor assessment for the prediction of angiographic coronary artery disease.

OBJECTIVE: To determine whether electron beam computed tomography (CT) adds to conventional risk factor assessment in the prediction of angiographic coronary artery disease. BACKGROUND: Electron beam CT scanning can be used to predict the severity of coronary atherosclerosis, but whether it does so independently of conventional risk factors is unclear. METHODS: Electron beam CT scans were performed and conventional risk factors were measured in 290 men and women undergoing coronary arteriography for clinical indications. The association of the electron beam CT-derived coronary artery calcium score and conventional risk factors with the presence and severity of angiographically defined coronary atherosclerosis was analyzed by logistic regression and receiver-operator characteristics analysis. RESULTS: Age, the ratio of total cholesterol to high-density lipoprotein (HDL) cholesterol and the coronary calcium score were significantly and independently associated with the presence of any coronary disease and obstructive coronary disease. In association with any coronary disease, odds ratios for age, the ratio of total cholesterol to HDL cholesterol and calcium score, highest quartile vs. lowest quartile, were 6.01 (95% confidence interval 2.87 to 12.56), 3.14 (1.56 to 6.31) and 94.08 (21.06 to 420.12), respectively. For obstructive coronary disease, highest quartile vs. lowest quartile, the respective odds ratios for age, the ratio of total cholesterol to HDL and calcium score were 3.86 (1.86 to 8.00), 4.11 (1.98 to 8.52) and 34.12 (12.67 to 91.86). Male gender was also significantly associated with any coronary disease (odds ratio 2.19, p=0.04) and obstructive coronary disease (odds ratio 2.07, p=0.04). Cigarette smoking was significantly associated with any coronary disease (odds ratio=2.74, p=0.004), and diabetes was significantly associated with obstructive disease (odds ratio 3.16, p=0.01). After adjustment for the coronary calcium score and other risk factors, it was determined that triglycerides, family history and hypertension were not significantly associated with any disease state. A coronary calcium score >80 (Agatston method) was associated with an increased likelihood of any coronary disease regardless of the number of risk factors, and a coronary calcium score > or = 170 was associated with an increased likelihood of obstructive coronary disease regardless of the number of risk factors (p < 0.001). CONCLUSIONS: Electron beam CT scanning offers improved discrimination over conventional risk factors in the identification of persons with any angiographic coronary disease or angiographic obstructive coronary disease.

Correlations between vascular calcification and atherosclerosis: a comparative electron beam CT study of the coronary and carotid arteries.

PURPOSE: Electron beam CT (EBCT)-derived coronary artery calcium scores correlate with the extent of atherosclerosis, but there is a substantial variance about the general relationship between coronary calcification and coronary atherosclerosis. The relationship between calcification and atherosclerosis may also differ in various arteries. This study was designed to evaluate whether the relation between carotid artery intima-media thickness (IMT) and carotid artery calcium could be used as a correction factor to improve the correlation between coronary calcification and coronary atherosclerosis. METHOD: We measured atherosclerosis in the coronary and carotid arteries by angiography and ultrasonography, respectively, and quantified coronary and carotid calcium deposition with EBCT in 50 subjects. The correlation between the findings in the carotid and coronary arteries was investigated. RESULTS: Coronary artery calcium score correlated with coronary angiography and with carotid calcium score. Coronary stenosis correlated with carotid IMT. There was no meaningful correlation of carotid IMT and carotid calcium. CONCLUSION: There is an intraindividual variation in the relationship of plaque mass to calcification among different vessels. The relation between carotid artery calcification and carotid IMT is not predictive of the relation between coronary artery calcification and coronary obstruction.

Relation of coronary calcium score by electron beam computed tomography to arteriographic findings in asymptomatic and symptomatic adults.

Coronary arteriography was performed on 18 asymptomatic, apparently healthy adults with elevated coronary calcium scores. To extend the range of observation to subjects with low calcium scores, arteriograms from 18 patients with exertional dyspnea and/or valvular heart disease and low calcium scores were also analyzed; these 18 patients were considered asymptomatic from the point of view of coronary artery disease (CAD). For the comparison of symptomatic and asymptomatic persons, 3 age and sex-matched symptomatic patients were also selected for each of the original 18 asymptomatic subjects. Arteriograms were analyzed by computer-assisted quantitative coronary arteriography at a remote site without knowledge of the calcium score or any other patient characteristics. In the 18 asymptomatic subjects with elevated calcium scores, the mean calcium score was 573 +/- 504 (Agatston method) and the mean worst stenosis was 45% +/- 16%. For all 36 patients without symptoms of CAD, worst stenosis was closely correlated with the square root of the calcium score (r = 0.85, p <0.0001). Patients with symptomatic coronary disease and calcium scores < 1,000 had stenoses more severe than asymptomatic persons with similar calcium scores. Most asymptomatic adults with elevated calcium scores have nontrivial, nonobstructive CAD or preclinical obstructive CAD, and the relation between coronary calcium score and severity of stenosis is highly significant. These data indicate that electron beam tomography can be used to estimate the severity of CAD in asymptomatic persons.

Predictive value of electron beam computed tomography of the coronary arteries. 19-month follow-up of 1173 asymptomatic subjects.

BACKGROUND: Coronary electron beam computed tomography (EBCT) detects atherosclerotic coronary artery disease by measuring calcium deposition in the walls of coronary arteries. EBCT-derived coronary artery calcium (CAC) scores correlate with the severity of underlying coronary artery disease. METHODS AND RESULTS: We followed 1173 asymptomatic patients who underwent EBCT between September 1993 and March 1994. During average follow-up of 19 months, 18 subjects had 26 cardiovascular events: 1 death, 7 myocardial infarctions, 8 coronary artery bypass graft procedures, 9 coronary angioplasties, and 1 nonhemorrhagic stroke. For CAC score thresholds of 100, 160, and 680, EBCT had sensitivities of 89%, 89%, and 50% and specificities of 77%, 82%, and 95%, respectively. Odds ratios ranged from 20.0 to 35.4 (P < .0001 for all). CONCLUSIONS: Coronary EBCT predicts future atherosclerotic cardiovascular disease events in asymptomatic subjects.

Subject selection biases in clinical trials: data from a multicenter schizophrenia treatment study.

To evaluate subject selection biases in clinical trials, demographic characteristics (gender, race, and age) of subjects at different phases of evaluation for a multicenter maintenance trial in schizophrenia were examined. Six thousand twelve diagnostically appropriate subjects were screened for the study; of these, 1,320 met eligibility criteria and 528 (9% of the screened sample) entered the study. Women, blacks, and older subjects were more likely not to meet eligibility criteria; women and older subjects were more likely and blacks were less likely to refuse study participation. Overall, compared with the screened population, the sample of subjects who entered the study contained proportionately fewer women (33 vs. 43%), more blacks (48.5 vs. 41%), and fewer older subjects (mean age of the entered sample was 29.4 +/- 7.4 vs. 34.8 +/- 11.3 years for the screened population). Having identified these selection factors, a second goal was to assess the potential clinical relevance of selection biases of these magnitudes on clinical trials using models of hypothetical studies with different degrees of selection bias. These showed that selection biases would rarely change overall study outcomes to a clinically relevant degree. However, in our models, selection biases did limit the ability to make inferences about results for select small subgroups of the study population. Investigators should consider collecting data on the recruitment process to allow estimation of the effects of selection biases on the generalizability of their findings.

Reduced caudate nucleus volume in obsessive-compulsive disorder.

BACKGROUND: Current hypotheses about the neuroanatomical structures involved in obsessive-compulsive disorder (OCD) suggest abnormalities in cortical-striatal-thalamic-cortical circuits. This study examined selected brain regions within or adjacent to these circuits. METHODS: Magnetic resonance imaging scans from 26 patients with OCD and 26 healthy controls were analyzed to determine the volumes of the following structures: prefrontal cortex (cortex anterior to the genu of the corpus callosum), caudate nucleus, lateral and third ventricles, and whole brain. RESULTS: Patients with OCD had significantly smaller caudate nucleus volumes than controls (F[1,48] = 9.4, P = .004) but did not differ in prefrontal cortex size or in volumes of the lateral or third ventricles. Structural volumes were not significantly correlated with the duration or severity of OCD symptoms. CONCLUSION: Our findings provide additional evidence for pathological involvement of the caudate in OCD.

Increase in caudate nuclei volumes of first-episode schizophrenic patients taking antipsychotic drugs.

OBJECTIVE: This study examined the pathomorphology of the caudate nuclei in first-episode schizophrenic patients with minimal previous neuroleptic exposure. METHOD: Magnetic resonance imaging (MRI) of the brain was used to examine longitudinally the caudate pathomorphology in 29 first-episode schizophrenic patients and 10 healthy comparison subjects. MRI scans were obtained after the subjects entered the study and at 18-month follow-up. The patients were treated with standardized neuroleptic regimens during the 18-month period. Volumetric assessments of the cerebral cortex, lateral ventricles, and caudate nuclei were performed on T1-weighted coronal brain sections. In addition, the patients were systematically evaluated for psychopathology at baseline and during treatment. RESULTS: Caudate volumes increased 5.7% in the patients during the 18-month treatment interval, whereas they decreased 1.6% in the comparison subjects over the same time period. Greater amounts of antipsychotic medication received by patients before the first scan and younger age at the time of the first scan were associated with larger increases in caudate volume. CONCLUSIONS: Caudate enlargement occurs early in the course of treatment in young first-episode schizophrenic patients. This may be a result of an interaction between neuroleptic treatment and the plasticity of dopaminergic neuronal systems in young patients.

[Membrane-destabilizing processes as the universal basis of inflammation]. / Membranodestabiliziruiushchie protsessy kak universal'naia osnova vospaleniia.

It is established that active pyelonephritis and operative stress are accompanied with structural and functional changes in erythrocytic membranes: cholesterol and its ethers rose in quantity as well as difficulty oxidized phospholipids, cation adenosine triphosphatase activity changed. Being nonspecific, these changes seemed more pronounced in the active phase of chronic pyelonephritis. Minor structural rearrangement of membrane lipids in surgical patients indicated uneventful postoperative period. It is suggested that bacterial inflammation in the kidneys and urinary tracts may be related to the above shifts. The adjuvant use of dimephosphone produced a clear-cut membrane-stabilizing effect clinically reflected by reduced inflammation and improved renal function.