Increase In Mean Frequency Research Articles

Relation of Immunoglobulin Level and White Blood Cell Count with Frequency of Infection in Splenectomized and Non-Splenectomized B Thalassemia Major Patients

Background: Beta-thalassemia major is an autosomal recessive condition caused by absent (β0) synthesis of the β globin chains of the hemoglobin tetramer. Objectives: Evaluation of immunoglobulin level and white blood cell count in splenectomized and non non splenectomized patient as well as comparison of the levels of Ig and WBC with frequency of infection. Materials and Methods: This cross sectional study included a total of 60 patients with beta-thalassemia major and 20 age and sex matched apparently healthy individual as a control, blood taken from them for an evaluation of immunoglobulin level and white blood cell count. Results: There is no significant difference in immunoglobulin level between splenectomized and non splenectomized B-thalassemia major patients and control groups. Also, there is significant increase in mean Frequency of infection / year for patients with thalassemia major in comparison to control, Specifically, splenectomized patients are having significant increase in frequency of infection in comparison to non splenectomizd. There is a significant difference in mean of White blood cell count, Neutrophil, Lymphocytes in patients with splenectomy, non-splenectomy and control group. Conclusion: Immunoglobulin levels are within normal range in thalassemia major patients whether splenectomized or non splenectomized. Leukocytes count mainly neutrophils and lymphocytes are higher in splenectomised patients. Frequency of infection is higher in splenectomed patients and there is a positive correlation with IgA and IgG.

Tocodynamometric study of uterine contractions during parturition in queens.

Tocodynamometry is an approach in small animal obstetrics to diagnose initiation, progress, completion, and problems related to parturition in queens. The present study was conducted to monitor uterine contractions using tocodynamometry at full term pregnancy and during queening and to correlate uterine contractile pattern with progression of queening. Once the signs of impending parturition were noted, the pressure transducer of tocodynamometer was placed on the lateral abdomen to monitor queening. The recordings were plotted as graph of time against pressure in mmHg. Uterine contractile patterns were assessed in order to study their relation to the progression of queening. The initial uterine contractions had a baseline and peak pressures of 7-20 and 15-36.5 mmHg with mean time interval and frequency of 5.53 min and 1.91 peaks per 10 min, respectively, with mean change of amplitude of 15.35 mmHg. The progressive baseline and peak pressures of 15-32.5 and 24-62.3 mmHg increased to 20-55 and 30-89.2, respectively, with an increase in mean frequency from 3.88 to 5.25 peaks per 10 min and increase in mean change of amplitude from 25.21 to 33.87 mmHg, followed by decrease in mean time interval from 2.82 to 1.91 min in expulsive uterine contractions. Monitoring uterine contractions using tocodynamometer helps in understanding progression of queening and problems that may rise during parturition. It was observed that during queening, baseline and peak pressures of uterine contractions remain the same, irrespective of presentation of kittens at birth.

In Silico Single-Fraction Stereotactic Ablative Radiation Therapy for the Treatment of Thoracic and Abdominal Oligometastatic Disease With Online Adaptive Magnetic Resonance Guidance

PurposeAlthough SABR can improve oncologic outcomes for patients with oligometastatic disease, treatment of metastases near critical organs remains challenging. The purpose of this study is to determine the dosimetric feasibility of delivering magnetic resonance imaging (MRI)-guided adaptive SABR in a single fraction for abdominal and thoracic metastases. Methods and MaterialsPreviously delivered MRI-guided radiation therapy plans for 20 patients with oligometastatic disease in the thorax or abdomen, with 70% (14/20) of the lesions within 8 mm from dose-limiting organs at risk (OARs), were used to simulate the delivery of 24 Gy in a single fraction. Planning objectives included planning target volume (PTV) V95% >90%, optimized PTV (PTVopt) V95% >90%, and PTVopt D99% >20 Gy with no OAR dose violations, where PTVopt removed overlap with nearby planning organ at risk volume (PRV). Single-fraction plans were simulated on the first 5 daily setup breath-hold MRI scans, and the plans were reoptimized to consider variations in setup position and anatomy. ResultsThe mean PTV V95% for single-fraction SABR plans was lower compared with multifraction plans (mean 85.4% vs 92.6%, P = .02), but mean PTVopt V95% was not different (95.3% vs 98.2%, P = .62). After reoptimization of the single-fraction plan to the treatment day MRI, there was an increase in mean PTV V95% (85.0% vs 88.1%, P = .05), increase in mean PTVopt V95% (92.7% vs 96.3%, P = .02), increase in mean PTVopt D99% (19.7 Gy vs 23.8 Gy, P < .01), increase in mean frequency of meeting PTV D99% >20 Gy (52% vs 87%, P < .01), and increase in mean gross tumor volume minimum dose (17.5 Gy vs 19.3 Gy, P < .01). Reoptimization decreased mean frequency of OAR dose constraint violation (48% vs 0%, P < .01). ConclusionsSingle-fraction MRI-guided SABR is a dosimetrically feasible treatment for oligometastases that allows for on-table adaptation to avoid OAR dose constraint violations, but this method requires clinical validation.

Atmospheric drivers of winter above‐freezing temperatures and associated rainfall in western Canada

AbstractWinter thaw episodes, especially when accompanied by rain, can significantly deplete the winter snowpack, which is a critical water storage component in the mountainous headwater regions of the major river basins of western Canada. Here we identify the characteristic synoptic‐scale mid‐tropospheric atmospheric circulation regimes that tend to foster such extreme hydrologic events using self‐organizing map analysis of meteorological reanalysis data from 1949 to 2012. Daily winter 500 hPa geopotential height fields over the Pacific Ocean and western Canada are classified into 12 dominant synoptic types, for which conditional probabilities of above‐freezing temperatures and rainfall are then calculated and mapped using daily high‐resolution gridded data. Results show that above‐freezing surface air temperatures and rain events in winter are commonly associated with the occurrence of a ridge of high pressure over western Canada, which induces southwesterly advection of relatively warm, moist maritime air masses into the continental interior, and that the intensity and spatial footprint of the surface climate response is related to the strength and position of the ridge. Conversely, the development of a ridge of high pressure over the Pacific Ocean and adjacent trough of low pressure over western Canada, which favours northwesterly to westerly mid‐tropospheric flow over the continental interior in winter, tends to suppress the occurrence of above‐freezing temperatures and rain. The synoptic type most strongly associated with winter thaw and rain events underwent a statistically significant step‐change increase in mean frequency in 1977, accompanied by a corresponding step‐change decrease in the frequency of the dominant synoptic type depicting westerly (zonal) circulation, coinciding with a well‐documented shift to a positive phase of the Pacific Decadal Oscillation.

Evaluation of genotoxicity by micronucleus assay in oral leukoplakia and oral squamous cell carcinoma with deleterious habits.

Background:Oral cancer is the 12th most common cancer in women and the 6th in men. Of all oral malignancies, more than 92-95% is Oral Squamous Cell Carcinoma (OSCC). The high risk was due to Lifestyle-related habits such as smoking, alcohol consumption, chewing of areca nut related products which are considered as the major risk factors in OSCC. The exogenous carcinogens from tobacco smoke may induce a defective DNA damage response, which may alter the expression of genes that protect us against cancer that may result in genomic instability and this DNA damage can be assessed by studying the chromosomal aberrations, sister chromatid exchanges and the varied forms of the micronucleus.Aims and Objectives:The aim of this study was to evaluate the risk of development of oral leukoplakia (OLP) and OSCC due to DNA damage by studying micronuclei count in the east coast of Andhra Pradesh population with tobacco consumption habit and habit-free controls using Fluorescent microscopy.Materials and Methods:A total of 60 subjects, 20 normal controls, 20 oral leukoplakia and 20 OSCC patients were selected from the outpatient patients of GITAM Dental College and Hospital, Rushikonda, Visakhapatnam and peripheral cancer hospitals in and around Visakhapatnam. Exfoliated cells were collected by giving 5-6 gentle strokes with spatula in a continuous unidirectional movement and then were uniformly spread on the previously cleaned microscopic slide. Fluorescent stain 4′, 6′-diamidino-2 phenylindole (DAPI) was used for MN analysis.Results:Mean of cells with MN in controls, leukoplakia and OSCC cases was observed to be 1, 5.1,10.1 (F = 112.396, P < 0.001) respectively. Mean of the cells with MN in different grades of leukoplakia. (F = 35.594, P < 0.001) Mean of the cells with MN in different grades of OSCC. (F = 39.752, P < 0.001).Conclusion:The present study revealed an increase in mean frequency of cells with micronucleus from healthy individuals however similar studies in larger sample has to be done. This study concludes that MN index can be used as a screening test among high risk groups.

Scent Marking and Factors Affecting on The Gestation Length in The Domestic Dog

Scent marking posture frequency of intact dogs and bitches was observed at two locations (kennel and open yard) in pre estrous and estrous phase in the domestic dog and effect of breed, age, parity and litter size of the gestation length. This study was carried out in Security and Guarding Dog Training Center, Cairo, Egypt. Twenty individuals (10 dogs and 10 bitches) for observation of scent marking posture, licking, sniffing the urine of female, tonguing response, sniffing and licking female perineal region, in pre estrous and estrous phase. Also data of 100 bitches were collected from the stud book record through the period between 2013-2015 analyzed to study the effect of breed, age, parity and litter size on the gestation length. The results indicated that there were a significant difference (p ≤ 0.05) between breeds, litter size and the gestation length, while no significant difference of age and parity of bitches. Also, there was a significant increase in mean frequencies of high leg raising, slight leg raising, squatting squat raising and raised leg display in dogs than in bitches and no significant difference in mean frequency of stand squatting. A significant increase in mean frequencies of licking and sniffing the urine of a bitch, tonguing response and sniffing and licking female perineal region and male investigating in the open yard.

FoxP3 demethylation is increased in human colorectal cancer and rat cholangiocarcinoma tissue

ObjectivesFoxP3 expression is a marker for Tregs which are known to be involved in tumor immunity. We aimed to evaluate FoxP3 promoter demethylation in human colorectal cancer (CRC) and rat intrahepatic cholangiocarcinoma (ICC). Design and methodsBisulfite-treated genomic DNA templates of shock frozen paired samples were studied from 13 anonymous CRC patients and from 10 male rats (n=6 ICC induced by thioacetamide and n=4 age-matched controls). Real-time PCR was carried out using a LightCycler 480 system. Human FoxP3 and CD3 promoter demethylations were estimated using previously described assays; and rat FoxP3 promoter demethylation using a newly developed assay. ResultsA significant 3.5-fold increase of the demethylation in FoxP3 promoter region was found in human CRC and rat ICC (P<0.05). The average frequency of cells with FoxP3 demethylation in patients suffering from CRC was 0.26% in normal tissue and 0.92% in tumor tissue (n=11 paired samples). Although, no significant difference was found between the mean frequency of CD3 demethylation in normal tissue (4.80%, n=6) and in tumor tissue (4.14%, n=6) from CRC patients, the ratio of demethylated CD3/FoxP3 promoter areas was significantly lower in tumor specimens (P<0.05). Using our novel assay, we found a significant increase in mean frequencies of cells with FoxP3 demethylation in rats with ICC (7.42%, n=6) in comparison to controls (2.14%, n=4). ConclusionFoxP3 seems to be an interesting biomarker for immune response to epithelial tumors. Functional consequences from the increase of Tregs remain to be demonstrated. Further studies with outcome data are necessary.

Chromosomal instability associated with a novel BLM frameshift mutation (c.1980‐1982delAA) in two unrelated Tunisian families with Bloom syndrome

The Bloom syndrome (BS) is an autosomal recessive disorder associated with dwarfism, immunodeficiency, reduced fertility and cancer risk. BS cells show genomic instability, particularly an hyper exchange between the sister chromatids due to a defective processing of the DNA replication intermediates. It is caused by mutations in the BLM gene which encodes a member of the RecQ family of DExH box DNA helicases. In this study, we reported cytogenetic, BLM linkage and mutational analyses for two affected Tunisian families. The Cytogenetic parameters were performed by chromosomal aberration (CA) and sister chromatid exchange (SCE) assays and results showed a significant increase in mean frequency of CA and SCE in BS cells. BLM linkage performed by microsatellite genotyping revealed homozygous haplotypes for the BS patients, evidence of linkage to BLM gene. Mutational analysis by direct DNA sequencing revealed a novel frameshift mutation (c.1980-1982delAA) in exon 8 of BLM gene, resulting in a truncated protein (p.Lys662fsX5). The truncated protein could explain genomic instability and its related symptoms in the BS patients. The screening of this mutation is useful for BS diagnosis confirmation in Tunisian families.

Increased frequency of micronucleated exfoliated cells among humans exposed in vivo to mobile telephone radiations

The health concerns have been raised following the enormous increase in the use of wireless mobile telephones throughout the world. This investigation had been taken, with the motive to find out whether mobile phone radiations cause any in vivo effects on the frequency of micronucleated exfoliated cells in the exposed subjects. A total of 109 subjects including 85 regular mobile phone users (exposed) and 24 non-users (controls) had participated in this study. Exfoliated cells were obtained by swabbing the buccal-mucosa from exposed as well as sex–age-matched controls. One thousand exfoliated cells were screened from each individual for nuclear anomalies including micronuclei (MN), karyolysis (KL), karyorrhexis (KH), broken egg (BE) and binucleated (BN) cells. The average daily duration of exposure to mobile phone radiations is 61.26 min with an overall average duration of exposure in term of years is 2.35 years in exposed subjects along with the 9.84 ± 0.745 micronucleated cells (MNCs) and 10.72 ± 0.889 total micronuclei (TMN) as compared to zero duration of exposure along with average 3.75 ± 0.774 MNC and 4.00 ± 0.808 TMN in controls. The means are significantly different in case of MNC and TMN at 0.01% level of significance. The mean of KL in controls is 13.17 ± 2.750 and in exposed subjects is 13.06 ± 1.793. The value of means of KH in exposed subjects (1.84 ± 0.432) is slightly higher than in controls (1.42 ± 0.737). Mean frequency of broken egg is found to be more in exposed subjects (0.65 ± 0.276) as compared to controls (0.50 ± 0.217). Frequency of presence of more than one nucleus in a cell (binucleated) is also higher in exposed (2.72 ± 0.374) in comparison to controls (0.67 ± 0.231). Although there is a slight increase in mean frequency of KH, BE and BN in exposed subjects but the difference is not found statistically significant. Correlation between 0–1, 1–2, 2–3 and 3–4 years of exposure and the frequency of MNC and TMN has been calculated and found to be positively correlated.

Isolation induced changes in Guinea Pig Cavia porcellus pup distress whistles.

Guinea Pig Cavia porcellus pups emit high-pitched distress whistles when separated from their mother. In order to assess the influence of the duration of a brief isolation period on whistle acoustic structure, we recorded the distress whistles of six 8-day old pups separated for 15 min from their group in a novel environment and compared the mean values of the first and last 30 whistle notes. Acoustic analysis revealed, throughout the session, a significant decrease in whistle duration, an increase in mean frequency and a tendency for a decrease in number of harmonics in the first part of the note. Results demonstrate that, throughout a brief isolation period, the vocal response of Guinea Pig pups to isolation undergoes structural changes possibly related to time-dependent changes in motivational state.

Character of distribution of defects of wing venation in the banded agrion (Calopteryx spendens)

The distribution of morphological structures was studied in wings of the banded agrion (Calopteryx splendens Harr.) from different intrapopulation groups. Dragon flies of odd years of emergence are characterized by a more stable pattern of ontogenetic processes accordin to the mean total number of venation defects. The sharply increased level of radiation in summer 1986, which coincided with the flight of dragon-flies, could have caused hereditary defects expressed in a sequence of generations of even years of emergence. Apparently, most alternative features of wing venation in dragon-flies can be considered as markers of stability of the ontogenetic processes, which reflect, to a great extent, genotypic features of the organisms in a population. A possible mechanism has been described, which explains the proposed topological model of formation of the venation defects of different types. The increase in mean frequencies of defects can suggest an enhanced development over the aberrant epigenetic trajectories, which may lead to the elimination of these organisms under the influence of various agents, i.e., to the stabilizing selection in a population. The results obtained suggest that defects of venation arise on the stochastic basis and their frequency increases upon destabilization of ontogenetic processes not only by the environmental factors, but also by genetic stress. Venation defects can be successfully used in population biomonitoring.

Presynaptic Ca2+Entry Is Unchanged during Hippocampal Mossy Fiber Long-Term Potentiation

The hippocampal mossy fiber (MF)-CA3 synapse exhibits NMDA receptor-independent long-term potentiation (LTP), which is expressed by presynaptic mechanisms leading to persistent enhancement of transmitter release. Recent studies have identified several molecules that may play an important role in MF-LTP. These include Rab3A, RIM1alpha, kainate autoreceptor, and hyperpolarization-activated cation channel (I(h)). However, the precise cellular expression mechanism remains to be determined because some studies noticed essential roles of release machinery molecules, whereas others suggested modulation of the ionotropic processes affecting Ca2+ entry into the presynaptic terminals. Using fluorescence recordings of presynaptic Ca2+ in hippocampal slices, here we demonstrated that MF-LTP is not accompanied by an increase in presynaptic Ca2+ influx during an action potential. Whole-cell recordings from CA3 neurons revealed long-lasting increases in mean frequency, but not mean amplitude, of miniature EPSCs after the high-frequency stimulation of MFs. These data indicate that the presynaptic expression mechanisms responsible for enhanced transmitter release during MF-LTP involve persistent modification of presynaptic molecular targets residing downstream of Ca2+ entry.

Fire Season and Dominance in an Illinois Tallgrass Prairie Restoration

AbstractNorth American prairie remnants and restorations are normally managed with dormant‐season prescribed fires. Growing‐season fire is of interest because it suppresses dominant late‐flowering grasses and forbs, thereby making available light and other resources used by subdominant grasses and forbs that comprise most prairie diversity. Here we report a twofold increase in mean frequency and richness of subdominant species after late‐summer fire. Stimulation of subdominants was indiscriminate; richness of prairie and volunteer species increased in species that flowered in early, mid‐, or late season. Early spring fire, the management tool used on this site until this experiment, had no effect on subdominant richness or frequency. Neither burn treatment affected reproductive tillering of the tallgrasses Sorghastrum nutans or Panicum virgatum. Flowering of Andropogon gerardii increased 4‐fold after early‐spring fires and 11‐fold after late‐summer fires. These preliminary results suggest that frequency and species richness of subdominants can be improved by late growing‐season fire without compromising vigor of warm‐season tallgrasses.

Effect of gastrin and H2-receptor antagonist on electrical control activity following canine intestinal transection

Our objective was to study the mechanism of action of gastrin and histamin H2 receptor antagonist on the motility of the gastrointestinal area. In each of 12 mongrel dogs, eight bipolar electromyograms were obtained from the antrum of the stomach to the ileum on serosal surface, and in nine dogs undergoing that the small intestine was transected 20 cm from the ligament of Treitz. The effects of tetragastrin (1.0-10.0 microgram.kg-1.h-1) were studied against the presence of atropine, cimetidine and d-chlorpheniramine maleate. The frequency of electrical control activity (ECA) along the canine small intestine, and changes in ECAs frequency were studied normal and following upper small intestinal transection. In intact, the frequency of ECAs gradient decreased aborally in a stepwise fashion in normal intestine. Although the gradient was markedly reduced or even abolished distal to the level of transection, an intrinsic ECAs frequency gradient was demonstrated, it remained at a low level indefinitely. The normal ECA pattern and its alterations following transection were significantly influenced by tetragastrin. The act of tetragastrin in a dose of 1.0 to 5.0 microgram.kg-1.h-1 had not statistically effect on ECAs frequency and its dysrhythmias, and it did cause a small increase in the frequency of ECA at the antrum, whereas, with the highest dose (10.0 microgram.kg-1.h-1) of used, the increase of mean frequency of ECA in the distal portion to the line of transection, in particular, was significantly greater compared to the change in the proximal portion. It was only cimetidine (8.0 mg.kg-1) that antagonized this action of tetragastin (10.0 microgram.kg-1.h-1). Histamine H2 receptors are suspected of being associated with the action the gastrin has of enhancing ECAs frequency. The results of this study indicate that histamine H2 receptors regularize gastrointestinal ECAs frequency.

Effects of the Removal of Phenytoin, Carbamazepine, and Valproate on the Electroencephalogram

We report the EEG changes that occurred on discontinuance of phenytoin (PHT), carbamazepine (CBZ), and valproate (VPA) in patients with active epilepsy. Discontinuation of CBZ was associated with an increase in mean frequency of dominant rhythm and reduction in amount of slow activity. Patients who had a marked increase in seizures on discontinuation of an antiepileptic drug had a slower mean dominant rhythm at baseline than did patients who did not have an increase in seizures. Subsequent EEGs, during and at the end of drug reduction, showed an increase in bursts of interictal epileptiform activity (IEA) and in slow activity in patients who had a marked increase in seizures. The amount of slow activity and IEA did not alter in patients who did not have an increase in seizures. No patients developed photosensitivity.

Cafeine et cartographie EEG: Effets d'une tache visuospatiale chez des volontaires sains. Strategie d'analyse des donnees electropharmacologiques

A group of 10 subjects, normal volunteers (6 men, 4 women), mean age 27.2 years, right-handers, has been selected for a double-blind study of caffeine effects (400 mg per os) versus placebo. One week delay separated the two EEG sessions quantified by spectral analysis. During each session (16 EEG channels, common reference), each subject was recorded four times: 2.5 min, in eyes-closed condition, under diffuse attention, followed by 2.5 min, during a visuo-spatial task ("eyes open" condition: presentation of a picture). These two EEG recordings were obtained before the oral administration and repeated 1 hr after the administration of caffeine or placebo. Individual and group results presented globally: 1) an increase in mean frequencies of alpha activity in "eyes closed" condition, and of delta activity in "eyes open" condition; 2) a decrease of alpha activity amplitudes (both RMS and % values) in both conditions; 3) a decrease of total RMS amplitudes in "eyes closed" condition; 4) an increase of relative % amplitudes for beta 2% fast activity in the "eyes open condition". These results characterize the psycho-stimulant effects of caffeine, especially over the left temporal area which was confirming an initial statistical hypothesis of specific cerebral local activation. The non-parametric permutation tests of Fisher, were not always reaching statistical significance for the same EEG channel quantified by one of the 17 analyzed spectral parameters, except on the left temporal area. During the visuo-spatial task, the decrease in alpha amplitudes (RMS and %) was also statistically significant, but over larger areas: over left and right temporal, central and parietal regions. In both conditions, eyes closed and eyes open, the alpha RMS amplitude was also decreased over the right anterior frontal area.

Changes in miniature end-plate potentials due to moderate hypertonicity at the frog neuromuscular junction.

The effect of an increase in tonicity on the amplitude and frequency of miniature end-plate potentials (m.e.p.p.s) following superfusion of 50 mM- or 100 mM-sucrose-Ringer solution was determined from intracellular recording at end-plates of the frog cutaneous pectoris muscle, in the absence of drugs and using on-line statistical analysis. An immediate decrease in mean amplitude of the order of 20% control was associated with a marked increase in mean frequency. A delayed increase in mean amplitude, independent of frequency, followed the initial response in the majority of end-plates exposed to 100 mM-sucrose-Ringer solution. The net gain was of the order of 34% and was attained over 20-40 min. This was not reversible over at least 20 min. There was an increase in the variability of m.e.p.p. amplitudes associated with the increase of mean amplitude but this was reversible. A moderate increase in tonicity is considered to induce two kinds of presynaptic changes. First, an immediate increase in the probability of release of smaller quantal packets and secondly, an increased loading of transmitter into vesicles within the readily releasable store.

Cytogenetic damage in workers exposed to ethylene oxide

Sister-chromatid exchanges (SCEs) and chromosomal aberrations (CAs) were detected in the peripheral lymphocytes of 41 sanitary workers exposed to ethylene oxide (EO) in the sterilizing units of 8 hospitals in the Venice Region. The first group (19 workers) was exposed to 10.7 ± 4.9 ppm EO, expressed as the time-weighted average concentration for an 8-h working day (TWA/8 h conc.), and the second group (22 workers) to 0.35 ± 0.12 ppm. Each exposed worker was paired with a control of similar age and smoking habits. A highly significant ( P < 0.001) increase in the mean frequency of SCEs was found in the higher exposure group, 14 (74%) exposed subjects having significantly increased levels of SCEs compared to their matched controls. In the lower exposure group, the increase in mean frequency of SCEs was lower, though still significant ( P < 0.05): 7 (33%) exposed subjects had higher and 1 (5%) had a lower SCE level than the matched controls. From the first group, 10 subjects, 7 of whom had increased SCE levels, were reanalysed 12–18 months after their exposure had been lowered or interrupted: in only 2 of them the SCE level was significantly decreased. A statistically significant correlation between SCE frequency and level of EO exposure (TWA/8h conc.), as well as a multiple correlation between SCE level and EO exposure, smoking and age were found. However, no interaction could be detected between EO exposure and smoking in the induction of SCEs. In controls, SCE frequency was correlated with smoking and age. In the higher exposure group, the number of both chromatid- and chromosome-type aberrations, independent of gaps, was significantly increased, whereas in the lower exposure group only the frequency of chromosome-type aberrations, excluding gaps, was statistically higher than in controls. Thed level of CAs remained to a great extent unchanged in the 10 subjects re-examined at a later stage after lowering or halting exposure. Taking the group as a whole, the frequency of cells with total CAs was found to be weakly ( P = 0.05) correlated with EO exposure, and was not correlated with smoking, age or SCE frequency.

Phenytoin

The electroencephalographic (EEG) and behavioral effects of oral doses of phenytoin from 100 mg to 1 g in normal male volunteers were measured. The electroencephalogram exhibited decreases in power in the slow frequencies and increases in the fast frequencies, accompanied by an increase in mean frequency. These changes are similar to those seen with psychostimulants. They occurred at average plasma levels of 8 micrograms/ml and above. The time course and the intensity of EEG effects parallel plasma levels. Drug-related EEG changes were bilaterally symmetric. EEG changes at plasma levels of 8--12 micrograms/ml were not associated with behavioral toxic signs. These findings suggest that future psychiatric studies of phenytoin as a psychostimulant should include monitoring for plasma levels, with a minimum of 8 micrograms/ml as a guide to clinical efficacy.

Computerized evaluation of electroencephalographic changes accompanying exchange transfusion in Reye's syndrome

The EEGs of 7 children with Reye's syndrome (fatty liver and encephalopathy) were continuously recorded on magnetic tape for times ranging from 12 to 80 h. During these times the major therapy consisted of exchange blood transfusions. The tapes were automatically processed on a LINC-8 computer using a peak-detection algorithm. The main parameters investigated were the delta and theta indices, the mean EEG frequency, the mean peak-to-peak amplitude, and the frequency versus amplitude characteristics of the delta waves. In 5 patients who responded to therapy, a marked decrease in the delta activity and an increase in mean frequency were noted subsequent to exchange transfusions. In all 5 cases the delta waves exhibited a similar pattern of decreasing amplitude and increasing frequency following therapy. However, in 2 patients with a fatal outcome, no favorable EEG response was observed during treatment, and a simultaneous decline in both delta frequency and delta amplitude was noted as the clinical condition worsened. The results of this study indicate that continuous EEG monitoring in Reye's syndrome may be an important clinical adjunct in evaluating the effectiveness of exchange transfusion therapy and in signaling the need for further treatment.