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PubMed2004

Factors associated with maternal-child separation among HIV-infected mothers.

The goal of this study was to determine the period prevalence of mother-child separation (i. e., living apart from mother) and factors associated with separation between women infected with HIV type 1 and their children (17 years old or younger). A retrospective cohort study was conducted, based on routinely collected data by the Family Advocacy, Care and Education Services (FACES) of Children's Hospital (New Orleans, Louisiana) on children (n 586) of 231 HIV-infected mothers followed from July 1, 2001 to March 20, 2003. The 3-month period prevalence of separation from mother ranged between 12.7% and 21.2% over the course of follow-up. At baseline, 14% of children were separated from their mothers. Over the course of follow-up, older children (6 to 17 years), those with mothers who used illegal drugs and/or alcohol and who suffered from mental health problem(s), those whose mothers did not live at a permanent residence, and children with mothers who had a CD4 cell count below 200 cells per microliter were more likely to be separated from their mother. No significant differences in substance use, mental health, CD4 count, or other sociodemographics were identified between women lost to follow-up and those who remained in care. Substance use and mental health problems played a role in maternal-child separation among the HIV-positive women in this sample, even after clinical status and socioeconomic factors were taken into account. Providing additional resources for substance use and mental health treatment may help to prevent or reduce maternal-child separation among similar populations.

Adolescent↗
PubMed1976

Influence of separation techniques on the distribution and function of lymphocyte subpopulations. A comparison of three techniques.

The effect, if any, of three different lymphocyte separation techniques on the composition and functional characteristics of the purified cell suspensions has been studied. Each separation technique was shown to yield a cell population with highly specific and reproducible characteristics. The Ficoll-Hypaque technique led to good lymphocyte yields but low yields of sheep erythrocyte-rosetting (E-rosetting) T cells, and the separated cell population responded least well to phytohemagglutinin. The glass sand filtration technique led to lowest overall yield of small lymphocytes and of EAC-rosetting cells. There was significantly lower total yield of E-rosetting T cell as well, but the separated lymphocyte suspension had excellent purity, had relatively high percentage of E-rosetting T cells, and they responded extremely well to phytohemagglutinin (PHA) and pokeweed mitogen (PWM). The Technicon separation involving magneticremoval of phagocytic cells by exposure to iron particles consistently led to large yields of small lymphocytes with good purity, the largest total harvests of E-rosetting T cells, as well as EAC-rosetting cells while the separated population had the highest percentage of E-rosetting cells and responded very well to PHA and PWM. These results show that lymphocyte losses during purification are not nonspecific and that the choice of the separation technique profoundly affects the characteristics of the purified lymphocyte population obtainable.

Cell Separation↗
PubMed2004

Assessment of efficacy of cell separation techniques used in the enrichment of foetal erythroblasts from maternal blood: triple density gradient vs. single density gradient.

The aim of this study was to determine the efficacy of cell separation with single density and triple density-gradient techniques in the yield of foetal erythroblasts isolated from maternal blood. Maternal blood was obtained from 20 singleton pregnancies at 11-14 weeks of gestation immediately before foetal karyotyping by chorionic villus sampling. In each woman, the blood sample was divided into two portions; one portion was used for single density-gradient separation and the other, for triple density-gradient separation. Magnetic cell sorting (MACS) was subsequently performed with anti-CD71/antiglycophorin-A. The enriched erythroblasts were stained with Kleihauer-Giemsa and with fluorescent antibodies for the gamma, epsilon and zeta globin chains. The percentage of foetal cells positive for each stain was calculated. Fluorescence in situ hybridization (FISH) for X- and Y-chromosomes was also performed. Comparison was made in the proportion of enriched foetal cells between the two separation methods for each CD71 and glycophorin-A (GPA) antibody. The percentage of erythroblasts enriched from maternal blood that stained positive for gamma, epsilon and zeta globin chains and with Kleihauer-Giemsa was significantly higher in the triple density-gradient separation fractions compared with the single density-gradient fractions with both anti-CD71 and GPA MACS. FISH analysis for the Y-chromosome confirmed the increase in foetal cell proportion in the triple density-gradient samples. Isolation of foetal erythroblasts from maternal blood using triple density-gradient separation and MACS is more effective with regard to foetal cell yield and purity than single density-gradient separation and MACS.

Cell Separation↗
PubMed2005

Clinical correlates and significance of separation anxiety in patients with bipolar disorder.

OBJECTIVES: To evaluate frequency and severity of separation anxiety (SA) symptoms, as well as frequency of DSM-IV diagnosis of childhood separation anxiety disorder (CSAD) and adult separation anxiety disorder (ASAD), in a group of patients with bipolar disorder (BD) when compared with patients with panic disorder (PD) or major depression (MDD) and to a control group of healthy individuals (HC). METHODS: Outpatients with, respectively, bipolar I disorder (BD), PD, MDD and a group of individuals with no psychiatric diagnoses (HC) were assessed for diagnosis by the SCID-I and for SA by the Structured Clinical Interview for Separation Anxiety Symptoms (SCI-SAS), the Separation Anxiety Symptoms Inventory (SASI) and the Adult Separation Anxiety Checklist (ASA-CL). RESULTS: Thirty-one patients with BD without comorbid PD (BD-PD), 22 with BD with comorbid PD (BD + PD), 24 with PD, 20 with MDD and 15 HC were included in the analyses. As to childhood SA, the BD-PD group had higher scores than PD group and HC. The BD + PD group had higher scores than the PD group, MDD group and HC. As to adulthood SA, the BD-PD group had higher scores than HC on both SCI-SAS and Adult Separation Anxiety Questionnaire (ASA-27). The BD + PD had higher scores on both scales than BD-PD, PD group, MDD group and HC. The PD group and MDD group had higher scores than HC on the ASA-27. Adult SA symptoms were significantly associated with an earlier age at onset of BD. CONCLUSIONS: This is the first study, to our knowledge, exploring the frequency and severity of SA symptoms during childhood and adulthood in a sample of bipolar patients in comparison to subjects with other anxiety and mood disorders. Our data appear to be preliminary grounds for investigating further the possibility that SA may deserve greater recognition in adults with BD.

Adult↗
PubMed1971

Effects of brief separation from mother on rhesus monkeys.

To summarize, data on the course of development of mother-infant relations in rhesus monkeys have been presented; a method for teasing apart the relative roles of mother and infant in causing changes or differences in the interaction described; and the complexity of the social nexus, within which the relationship is set, stressed. When the mother is removed for a few days, the infant calls a great deal at first and then shows depressed locomotor and play activity. These symptoms may last for a month after the mother's return. Simple tests given 6 months and even 2 years later strongly suggest that the differences (between infants that have had such a separation experience and infants that have not) are persistent. Are these data relevant to the human case? The rhesus monkey has no verbal language and a much less complex social development than man. Furthermore, its social environment is quite different from that found in any human culture. Parallels between monkey and man must therefore be scrutinized carefully before being used as a basis for generalization. But the facts show that a brief separation experience produces in rhesus monkey infants symptoms that are very similar (except for the apparent absence of a "phase of detachment" on reunion) to those in human infants (25). While age of separation, within the rather narrow limits used here, was a variable of minor importance, the effects of the separation varied, as in the human case, with the length of the separation experience and the sex of the infant. Differences in the techniques of experimenters, as well as differences in the species, prevent precise comparisons of the roles of the mother-infant relationships; nevertheless, the nature of the relationship appears to be an important variable in both monkey and man. There would seem, therefore, to be strong reasons for thinking that we are dealing with comparable phenomena. If that is the case, the fact that monkeys function at a simpler conceptual level than man limits the complexity of the explanatory hypotheses necessary in the human case. In addition, the finding that such a brief separation experience, involving removal of the mother but no exposure to a strange environment, can produce effects lasting for months or years in rhesus monkeys strengthens the evidence that long-term effects may occur also in man. Finally, this analysis provides bases for attempts to predict individual differences in the effects of a period of separation on rhesus infants, and the parallels with man suggest that examination of the same variables in the human case would be worthwhile.

Animals↗
PubMed1984

Relationship between separation anxiety and panic and agoraphobic disorders.

The paper addresses several issues pertinent to the characteristics and treatment of separation anxiety in children and adults. The rationale for separating separation anxiety from other childhood anxiety conditions rests on clinical observations of its relationship to panic disorder and its response to drug treatment. The psychopharmacological treatment of separation anxiety is reviewed, with special emphasis on the use of tricyclic antidepressants. The literature relevant to a possible association between separation anxiety and adult panic disorder is presented. The prevalence of separation anxiety disorder in adult outpatients with panic disorder is discussed. Data are presented to address the issue of treatment response in adult panic disorders with and without separation anxiety.

Adult↗
PubMed2006

Platelet separation from whole blood in an aqueous two-phase system with water-soluble polymers.

Platelet-rich plasma (PRP) stimulates tissue healing and centrifugation is the only method for PRP preparation. The purpose of the present study was to develop a method to separate platelets without centrifugation. We used 16 polymers of different chemical characteristics and mixed each polymer with fresh whole blood containing anticoagulant citrate-dextrose. Then, we observed blood cell separation. Focusing on the effective polymers and comparing our method with the conventional centrifugation method, we examined platelet recovery rate and P-selectin expression, which represents platelet activation. Poly-L-glutamic acid (PGA) and poly-L-aspartic acid (PAA) separated platelets efficiently; however, these polymers activated platelets. On the contrary, poly (2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB), which has phosphorylcholine residues mimicking a cellular membrane molecule, separated platelets moderately and the PMB-separated platelets were nearly inactive compared to the separation with the ordinary centrifugation and PGA. Conclusively, the present experiments demonstrated that without centrifugation platelets can be separated from whole blood with some water-soluble polymers, such as PGA, PAA, and PMB, and that PMB has an advantage not to activate platelets.

Biopolymers↗
PubMed1997

Is there an adult form of separation anxiety disorder? A brief clinical report.

OBJECTIVE: The aim of this clinical report is to investigate whether symptoms of separation anxiety disorder can occur in adulthood. CLINICAL PICTURE: Three cases are described to illustrate that adults may experience: wide-ranging separation anxiety symptoms, such as extreme anxiety and fear, when separated from major attachment figures; avoidance of being alone; and fears that harm will befall those close to them. Symptoms of panic appeared to be secondary to separation anxiety, and none of the patients fulfilled criteria for dependent personality disorder. TREATMENT: Group cognitive behavioural treatment focusing on preventing panic attacks and generalised anxiety did not appear to have an impact on core separation anxiety symptoms. OUTCOME: Exacerbations of separation anxiety appeared to be closely linked to actual or threatened ruptures to primary bonds. CONCLUSIONS: Separation anxiety disorder may be a neglected diagnosis in adulthood. Formal nosological systems such as the DSM may need to be revised to incorporate adult manifestations of the disorder.

Adult↗
PubMed2000

Mother's attachment concerns regarding spouse and infant's temperament as modulators of maternal separation anxiety.

The modulators of maternal separation anxiety were examined in a longitudinal study with 97 mothers of infants from 3 to 9 months of age. The objective of the study was to examine the joint contribution of the mother's attachment concerns as related to her husband together with the perception of the infant's temperament to her concerns over separation from her child. Maternal worries about separation from 3-month-old infants predicted maternal separation anxiety when infants were 9 months old. Mother's attachment to her husband and her perception of her child's temperament further predicted maternal separation anxiety at 9 months over and above the worries at 3 months. Mothers who feared dependent relationships with their husbands experienced high levels of maternal separation anxiety. This tendency was particularly marked when the infant was perceived as adaptable at 3 months. In addition, secure mothers, namely, mothers low in fear of abandonment and in fear of being dependent, increased their maternal separation anxiety as a function of their infant's perceived unadaptability.

Adult↗
PubMed1992

The stressfulness of separation among nine-month-old infants: effects of social context variables and infant temperament.

This manuscript reports on the results of 2 experiments dealing with behavioral and adrenocortical responses to separation among 9-month-old human infants. In both experiments the social context of separation was manipulated. The results of Experiment 1 yielded evidence of a statistically significant adrenocortical response to 30 min of separation under conditions in which the substitute caregiver responded sensitivity to infant distress, but was busy and relatively noninteractive when babies were not distressed during the separation period. Altering the behavior of the substitute caregiver such that she was warm, responsive, and interactive throughout the separation produced a significant reduction in adrenocortical activity and in negative affect. In fact, these measures were not significantly different than those obtained when the mother and infant remained together in the playroom (No Separation). In Experiment 2, the effects of group versus singleton care were examined using the less stressful mode of substitute caregiving as described above. No significant condition differences in behavioral distress or cortisol were found. Furthermore, neither condition elicited a significant increase in cortisol over basal levels. Finally, these data provide evidence that maternal reports of infant Distress to Limits temperament, using Rothbart's Infant Behavior Questionnaire, predict adrenocortical responses to separation, while reports of Fear of Novelty do not.

Adrenal Cortex↗
PubMed1974

Comparison of certain functions of human platelets separated from blood by various means.

Human platelets separated from blood by six different methods have been compared for aggregability, adhesion to glass, adenine nucleotide content and release, and adenosine triphosphatase and cholinesterase activities. Methods of separation of platelets from blood included three differential centrifugation technics, gel filtration and two albumin density gradient methods. Platelets prepared by the different methods aggregated comparably except those separated by albumin density gradient technics which tended to be hyporeactive. Differences in adhesion to glass, adenine nucleotide content and release, and monitored enzyme activities of the various platelet preparations were noted in several cases but were not marked in general. Ultrastructural studies, reported elsewhere, revealed that platelets separated by the method of Mustard or by gel filtration were less altered morphologically than those separated by the other methods. Platelets separated from blood by gel filtration also appeared somewhat superior functionally to platelets separated by other methods.

Adenosine Diphosphate↗
PubMed1980

The separation of human palatine tonsillar cells in the reorienting gradient zonal rotor: a large-capacity enrichment of plasma cells.

Velocity sedimentation by centrifugation in a previously described isokinetic gradient, at unit gravity, or with an elutriator has proved to be highly effective as a method for the enrichment of many kinds of cells. For many biochemical and immunological purposes, the available techniques for the separation of cells have been incapable of separating a sufficient number of cells. With a newly designed rotor, we have separated more than twenty-fold more human tonsillar cells that can be separated in the previously described isokinetic gradient. Without exceeding the band capacity, we separated 692 million tonsillar cells. Plasma cells were more than seven-fold enriched from human tonsillar cells. When 692 million tonsillar cells were separated in the rotor, the five most enriched, contiguous fractions of plasma cells contained 44 million cells. The most enriched fraction contained 27% plasma cells. We are not aware of any method for velocity sedimentation which will separate such large numbers of tonsillar cells.

Cell Count↗
PubMed1994

[Results of cell separation with new single needle techniques in comparison with a current dual needle technique].

BACKGROUND: In plateletpheresis, new single-needle techniques have been introduced for the cell separators A 201 and AS 104. These techniques were compared with the well established CS 3000 Plus cell separator, which uses the continuous flow system. MATERIAL AND METHODS: Donation time, ACD consumption, platelet yield, separation efficiency, erythrocyte and leukocyte contamination were studied in different protocols with the dual- and single-needle procedure. RESULTS: Total amount of thrombocytes and separation efficacy were lowest with the A 201 device. The separation efficiency was best with the single-needle version of the AS 104 separator due to reprocession of the blood during the return cycle to the centrifuge. Leukocyte contamination was lowest with the standard procedure of the CS 3000 Plus device. CONCLUSIONS: The single-needle technique of the AS 104 blood cell separator resulted in sufficient platelet collection. The purity of the platelet concentrates collected with the A 201 and AS 104 machine has to be improved.

Cell Separation↗
PubMed1978

Nocturnal sleep in separated monkey infants.

Nocturnal sleep was recorded from ten unrestrained, group-living Macaca nemestrina (pigtail) monkey infants, using implantable multichannel biotelemetry systems, during the agitation-depression behavioral reaction that follows maternal separation. Sleep disturbances during the four nights of separation were characterized by decreases in rapid eye movement (REM) time and in the number of REM periods, and increases in REM latency. Time awake and number of arousals were increased. Slow-wave sleep was not significantly affected. Sleep pattern changes were most pronounced the first separation night, and tended to decrease as separation continued, whereas behavioral measures of depression tended to increase as separation continued (up to four days). Sleep patterns returned to normal following reunion with the mother. Those infants who had the most severe sleep disturbances the first separation night (more time awake, less total sleep, less REM) also tended to become most depressed behaviorally later in the separation period.

Animals↗
PubMed1979

Boundary layer separation in models of side-to-end arterial anastomoses.

We performed an investigation of boundary layer separation in models of side-to-end anastomoses, used clinically in axillofemoral and femorofemoral grafting. Boundary layer separation occurs when momentum causes a fluid to flow against a local pressure gradient. Models of side-to-end anastomoses were constructed from Dacron grafting material and from clear plastic blocks and tubing. Fluid energy loss across the anastomosis was small and physiologically insignificant. Local adverse pressure gradients were demonstrated near the anastomosis. Flow visualization studies demonstrated characteristic areas of boundary layer separation in the region of the adverse pressure gradients. The separation region involved both the main limb and the side arm. The separation forms a shell or ring of slow-moving fluid around the mainstream. Preliminary studies with pulsatile flow and with blood demonstrate that boundary layer separation occurs under clinical flow conditions. Boundary layer separation may play a role in the development of anastomotic hyperplasia and atherosclerotic deposits in the vicinity of surgical anastomoses.

Arteriosclerosis↗
PubMed1999

When a truck becomes a motorcycle: the impact of sample load on a chiral capillary electrophoresis separation using mixtures of neutral and sulfated cyclodextrins.

Chiral capillary electrophoresis (CE) separations are useful for monitoring the presence of a minor isomer at low levels (e.g., <0.5%) in the presence of the major form. In order to quantitate these low levels, it is necessary to inject large amounts of sample. Separations which appear to have more than enough resolution ("big enough to drive a truck through) for dilute, equal-concentration mixtures of isomers can become inadequately resolved when the necessary amount of sample is injected. This paper addresses some important considerations in maintaining adequate resolution at high sample loads for chiral separations involving a dual-cyclodextrin (CD) system. For hydrophobic compounds, the use of both a neutral and a sulfated CD can be helpful in achieving a chiral separation. In such a system, the migration time and resolution can be controlled by varying the ratio of neutral to charged CD concentrations. It is demonstrated here that not only the ratio, but also the total CD concentration can significantly affect the separation. In this paper, the impact of the total CD concentration in a dual-CD system (with the concentration ratio constant) is examined with respect to peak shape and resolution. The influences of temperature, capillary diameter, and current are also considered. The corresponding impact on the amount of sample which can be loaded and successfully separated determines the limit of quantitation of the minor isomer. Thus, this information is important in making such chiral separations applicable to determinations of low levels of minor isomer in the presence of large amounts of the major form.

Cyclodextrins↗
PubMed2000

Comparison of a jet separator and an open splitter as an interface between a multi-capillary gas chromatographic column and a time-of-flight mass spectrometer

A gas chromatographic/time-of-flight mass spectrometric (GC/TOFMS) interface is being developed for fast on-line analysis utilizing multi-capillary column technology. A variable gap-distance jet separator has been constructed and its performance compared with that of a commercially supplied post-column open splitter recommended for use between the multi-capillary column and a mass spectrometer. Both interfaces were found to be compatible with the GC/TOFMS system at high carrier gas flow-rates, facilitating high-speed and high-resolution separations. The systems were investigated and tested with a mixture of volatile organic compounds (VOCs) with molecular masses from 85 to 166: dichloromethane, toluene, m-dichlorobenzene, o-dichlorobenzene and tetrachloroethylene. The optimum tip-to-tip gap distance corresponding to the highest efficiency of the jet separator was found to be 0.030 mm for each compound at carrier gas flow-rates of 20, 40 and 60 ml min(-1) giving, in the ion source housing, ion gauge pressure readings of 1.6 x 10(-6), 5.0 x 10(-6) and 5.8 x 10(-6) mbar, respectively. The efficiency of the jet separator (10-30% yields) was significantly higher than that of the open splitter (6-9% yields). The observation that the open splitter did not provide a constant flow-rate to the ion source was not in agreement with the manufacturer's specifications. A method for measuring the gas flow-rates in all parts of the equipment is described. The correlation between yield in the jet separator and molecular mass for the heterogeneous set of compounds studied was found to be less linear than usually reported for homologous series of compounds in jet separator studies. The result suggests that the pressure conditions in the jet may be sufficient for the separation process to be partly controlled by diffusion rather than predominately by effusion. Copyright 2000 John Wiley & Sons, Ltd.

Journal Article↗
PubMed2000

On-chip chiral and achiral separation of amphetamine and related compounds labeled with 4-fluoro-7-nitrobenzofurazane.

Amphetamine and analogous compounds have been labeled with 4-fluoro-7-nitrobenzofurazane and analyzed on a microfabricated chip. Separation of norephedrine, ephedrine, cathinone, pseudoephedrine, methcathinone, amphetamine and methamphetamine is demonstrated using micellar electrokinetic capillary chromatography (MEKC) and laser-induced fluorescence (LIF) detection. Chiral separations of individual drugs were studied using neutral and negatively charged cyclodextrins (CDs) with and without the addition of an organic modifier and/or sodium dodecyl sulfate (SDS). The best results were obtained using a highly sulfated gamma-CD (HS-gamm-CD) in combination with a low concentration of SDS. To obtain complete separation of a mixture of (+/-)-norephedrine, (+/-)ephedrine, (+/-)-pseudoephedrine, (+/-)-methcathinone, (+/-)-amphetamine and (+/-)-methamphetamine it was necessary to add a small amount (1.5 mM) of SDS to the separation buffer. Optimized chiral separation was achieved within 7 min using an S-folded separation channel, a separation voltage of 8 kV and a buffer consisting of 50 mM phosphate (pH 7.35), 10 mM HS-gamma-CD and 1.5 mM SDS.

4-Chloro-7-nitrobenzofurazan↗