Peripheral monocytes of obese women display increased chemokine receptor expression and migration capacity.

CONTEXT: The activation of peripheral immune cells and the infiltration of immune cells into adipose tissue in obesity are implicated in the development of type 2 diabetes mellitus. OBJECTIVE: The aim of the study was to compare peripheral immune cells from obese and normal-weight women with regard to composition of immune cell subpopulations, surface expression of the chemokine receptors (CCRs) CCR2, CCR3, CCR5, and CXCR3 (chemokine (C-X-C motif) receptor 3) and cell-intrinsic migration capacity. DESIGN: This was a case-control study. SETTING: The study was conducted at a university clinical study center. PATIENTS: Obese females and normal-weight females were included for fluorescence-activated cell sorting analysis and migration assays. MAIN OUTCOME MEASURES: Peripheral blood mononuclear cells were prepared from fasting blood samples and used for fluorescence-activated cell sorting analysis and migration assays. RESULTS: An increase in the percentages of CD14(+)CD16(+) monocytes was observed in obese subjects compared with controls. The CCR profile of monocytes differed significantly in the obese state; in particular, CCR2 levels were increased. In addition, a higher chemotactic activity of monocytes from obese subjects was observed in a migration assay, which was associated with both insulin resistance and CCR2 expression. CONCLUSION: Our results suggest that the enhanced intrinsic migratory capacity of peripheral monocytes in obese women may be due to the increased CCR expression, further supporting a link between peripheral immune cell dysfunction and obesity.

Primary and secondary plasmodesmata: structure, origin, and functioning.

In the multicellular organisms of higher plants, plasmodesmata provide pathways for intimate symplasmic communication between neighboring cells. The arguments summarized in the present review demonstrate that plasmodesmata are diverse and highly dynamic structures. Differences in the plasmodesmal origin and modifications of the plasmodesmal structure and functioning at the various cell interfaces are the basic means which give rise to a complicated and flexibile symplasmic network. This complex communication system is discussed to serve a significant role in the coordinated development and in the concerted physiological functioning of the cells within the plant tissues, organs, and organisms.

Reversible calcium-regulated stopcocks in legume sieve tubes.

Sieve tubes of legumes (Fabaceae) contain characteristic P-protein crystalloids with controversial function. We studied their behavior by conventional light, electron, and confocal laser scanning microscopy. In situ, crystalloids are able to undergo rapid (<1 sec) and reversible conversions from the condensed resting state into a dispersed state, in which they occlude the sieve tubes. Crystalloid dispersal is triggered by plasma membrane leakage induced by mechanical injury or permeabilizing substances. Similarly, abrupt turgor changes imposed by osmotic shock cause crystalloid dispersal. Because chelators generally prevent the response, divalent cations appear to be the decisive factor in crystalloid expansion. Cycling between dispersal and condensation can be induced in opened cells by repetitive exchange of bathing media containing either Ca(2)+ or chelators. Sr(2)+ and Ba(2)+, but not Mg(2)+, are equally active. In conclusion, the fabacean P-protein crystalloids represent a novel class of mechanically active proteinaceous structures, which provide an efficient mechanism with which to control sieve tube conductivity.

Validity of structured clinical evaluations in adolescents with conduct and substance problems.

OBJECTIVE: To determine discriminative and convergent validity for certain structured diagnostic assessments among adolescents with conduct and substance problems. METHOD: Patients were 87 adolescents (both genders) in treatment for conduct and substance problems. Most controls (n = 85; both genders) came from patients' neighborhoods. Assessments included Diagnostic Interview Schedule for Children, Composite International Diagnostic Instrument-Substance Abuse Module, Child Behavior Checklist, and others. Patients' data guided clinical care. RESULTS: Youths' self-reports significantly discriminated patients from controls in DSM-IVconduct and substance use disorders (CD, SUD) and in numerous associated measures. CD and SUD symptoms correlated strongly. However, some patients apparently minimized symptoms. Youths' self-reports did not discriminate patients from controls in attention-deficit/hyperactivity disorder (ADHD) or major depression (MDD). Parent information raised prevalence rates of ADHD and MDD, which then discriminated patients from controls. However, patients and parents usually disagreed on MDD and ADHD diagnoses. CONCLUSIONS: Despite some dissimulation, patients' self-reports of CD and SUD correlated highly and had superb discriminative validity, making them useful for treatment and research. Self-reports of ADHD and MDD, apparently lacking discriminative validity, are less useful. Parent reports improve these discriminations but present additional problems.

Dependence of virtual wedge factor on dose calibration and monitor units.

One of the important features of the Siemens Virtual Wedge (VW) is that the VW factor (VWF) is approximately equal to unity for all beams with a total deviation for a given wedge no greater than 0.05, as specified by Siemens. In this note we report the observed dependence of VWF on dose calibration (cGy/MU), monitor units (MU), and beam tuning for a Primus, a linear accelerator with two dose-rate ranges available for VW operation. The VWF is defined as the ratio of doses measured on the beam central axis for the wedge field to the open field; the open field dose is always measured with the nominal high dose-rate beam. When VW operates in the high dose-rate range, the VWF is independent of calibration (cGy/MU). When VW works in the low dose-rate range, the VWF varies linearly with the calibration of the low dose-rate mode. For a linear accelerator that has only one dose-rate range for VW, there is no observable dependence of VWF on the calibration. We also studied the monitor unit dependence of VWF. A discontinuity in VWF was observed at the switching point between the high and low dose-rate ranges. Working with Siemens, we have investigated causes of this discontinuity. As a result of this investigation, the discontinuity in VWF as a function monitor unit is practically removed.

Ultrastructure of minor-vein phloem and assimilate export in summer and winter leaves of the symplasmically loading evergreens Ajuga reptans L., Aucuba japonica Thunb., and Hedera helix L.

Minor-vein ultrastructure and sugar export were studied in mature summer and winter leaves of the three broadleaf-evergreen species Ajuga reptans var. artropurpurescens L., Aucuba japonica Thunb. and Hedera helix L. to assess temperature effects on phloem loading. Leaves of the perennial herb Ajuga exported substantial amounts of assimilates in form of raffinose-family oligosaccharides (RFOs). Its minor-vein companion cells represent typical intermediary cells (ICs), with numerous small vacuoles and abundant plasmodesmal connectivity to the bundle sheath. The woody plants Hedera and Aucuba translocated sucrose as the dominant sugar species, and only traces of RFOs. Their minor-vein phloem possessed a layer of highly vacuolated cells (VCs) intervening between mesophyll and sieve elements. Depending on their location and ontogeny, VCs were classified either as companion or parenchyma cells. Both cell types showed symplasmic continuity to the adjacent mesophyll tissue although at a lower plasmodesmal frequency compared to the Ajuga ICs. p-Chloromercuribenzenesulfonic acid did not reduce leaf sugar export in any of the plants, indicating a symplasmic mode of phloem loading. Winter leaves did not show symptoms of frost injury, and the vacuolar pattern in ICs and VCs was equally prominent in both seasons. Starch accumulation as a result of reduced phloem loading was not observed to be triggered by low temperature. In contrast, high amounts of starch were found in mesophyll and bundle-sheath cells of summer leaves. Physiological data on season-dependent leaf exudation showed the maintenance of sugar export in cold-acclimated winter leaves.

One-year outcome of adolescent females referred for conduct disorder and substance abuse/dependence.

We investigated whether substance abuse/dependence, conduct disorder, and other psychiatric disorders improved in adolescent females who were referred to outpatient treatment and which variables were related to 1-year outcome. Forty-six out of 60 conduct-disordered (CD) adolescent females with substance abuse or dependence were re-evaluated approximately 1 year after discharge. Treatment length averaged 16 weeks. Significant improvements were seen in three areas: (1) criminality and CD; (2) attention deficit hyperactivity disorder (ADHD); and (3) educational and vocational status. However, neither substance involvement nor depression improved, regardless of length of stay in treatment, and these females demonstrated significant risky sexual behaviors. In contrast to our previous work with adolescent males (Crowley, T.J., Mikulich, S.K., Macdonald, M., Young, S.E., Zerbe, G.O., 1998. Substance-dependent, conduct-disordered adolescent males: severity of diagnosis predicts 2-year outcome. Drug Alcohol Depend. 49, 225-237), we were not able to identify pre-intake variables, other than performance IQ, that were related to substance use and conduct outcomes. Only two post-treatment factors (peer problems and number of ADHD symptoms at follow-up) were found to be related to CD and substance use disorders outcomes. The overall lack of pre- and post-treatment predictors presents interesting challenges for future research on adolescent females with these disorders.

Synchronization of mitotic activity in protoplast-derived Solanum nigrum L. microcalluses is correlated with plasmodesmal connectivity.

In protoplast-derived Solanum nigrum microcalluses, plasmodesmal connectivity and cell division behaviour of the sister cells were examined by repeated pressure-injection experiments with the fluorescent dye Lucifer Yellow (LYCH; M(r) 457) and concomitant light-microscopical long-term live observations. The studies revealed that the plasmodesmal permeability of the cultured cells differs in the distinct stages of microcallus development. There was a correlation between the symplasmic connectivity of the cells and the synchronousness of their mitotic activity. Sister cells which were symplasmically interconnected by functional plasmodesmata, permitting the diffusion of LYCH, were always found to divide synchronously. However, asynchronous mitotic divisions were exclusively observed in those sister cells whose plasmodesmata were closed to LYCH. The temporary symplasmic isolation is presumably performed by reversible gating of plasmodesmata. Repeated dye-coupling experiments on the same microcalluses showed that symplasmically interconnected sister cells may become uncoupled and vice versa, according to their division behaviour. These findings on cultured cells indicate that modulation of the symplasmic connectivity determines the synchronization of mitotic activity. Yet it remains to be proven whether this is true in planta as well. The results are discussed with respect to the possible role of plasmodesmata in exerting "supracellular control" over mitotic activity by trafficking mitosis-regulating signals.

Phenotypic features and impact of beta blocker or calcium antagonist therapy on aortic lumen size in the Marfan syndrome.

Systematic, prospective data regarding phenotypic features, including echocardiographic findings, in pediatric patients with the Marfan syndrome are lacking. In addition, limited and conflicting information exists regarding the impact of pharmacologic therapy on aortic growth rate in children. Fifty-three children and adolescents with the Marfan syndrome underwent physical examination, anthropometric evaluation, and echocardiography. The relation of pharmacologic therapy to aortic growth rate was examined in the 44 subjects in whom serial echocardiograms were recorded. Although boys and girls did not differ in ocular, skeletal, or cardiovascular manifestations, aortic dilatation tended to be more common in boys (86% vs 72%). Children with aortic dilatation at baseline (42 of 53 or 79%) were more likely to also have scoliosis and mitral prolapse (both p <0.005). The medicated patients had slower aortic growth than the unmedicated patients with regard to both absolute aortic growth rate (p <0.01) and aortic growth rate adjusted for age and body size (p <0.005). Nevertheless, major cardiovascular complications developed in 5 patients despite long-term pharmacologic therapy. In conclusion, beta-blocker and calcium antagonist therapy retards aortic growth rate in children and adolescents with the Marfan syndrome.

Studies on the teratogen pharmacophore of valproic acid analogues: evidence of interactions at a hydrophobic centre.

Propyl-4-yn-valproic acid (2-propyl-4-pentynoic acid), an analogue of valproic acid with a triple bond in one alkyl side chain, potently induces exencephaly in mice. Given that propyl-4-yn-valproic acid is a branched chain carboxylic acid, we synthesized a series of analogues with n-alkyl side chains of increasing length and correlated their potential to induce neural tube defects and to inhibit proliferation and induce differentiation in cells of neural origin, the latter being crucial to the orderly structuring of the embryo. All analogues significantly increased the incidence of neural tube defects in the embryos of dams exposed to a single dose of 1.25 mmol/kg on day 8 of gestation. This effect occurred in a dose-dependent manner and the rate of exencephaly increased with the progressive increase in n-alkyl side chain length. Moreover, increasing chain length resulted in a dose-dependent inhibition of C6 glioma proliferation rate over a concentration range of 0-3 mM and this was independent of the cell type employed and mode of estimating proliferative rate. The antiproliferative action of these analogues was associated with profound shape change in neuro-2A neuroblastoma involving extensive neuritogenesis and an associated increase in neural cell adhesion molecule (NCAM) prevalence at points of cell-cell contact, the latter exhibiting a dose-dependent increase when the n-alkyl chain was extended to five carbon units. These results suggest an interaction with a specific site in which the n-alkyl side is proposed to serve as an 'anchor' within a hydrophobic pocket to facilitate the ionic and/or H-bonding of the carboxylic acid and high electron density of the carbon-carbon triple bond.

Valnoctamide, valpromide and valnoctic acid are much less teratogenic in mice than valproic acid.

The teratogenic properties of valproic acid (VPA) and its analogues depend to a great extent on their chemical structure. We investigated the structure-teratogenicity relationships of VPA, its structural isomer, valnoctic acid (VCA), and their two amide analogues, valpromide (VPD) and valnoctamide (VCD), respectively. Each substance was injected (3 mmol/kg) in NMRI-mice on the morning of day 8 of gestation. Embryolethality, fetal weight and exencephaly rates were recorded on day 18 of gestation. VPA caused 53% exencephaly, VPD induced 6%, VCA and VCD produced only 1% exencephaly (control values between 0 and 1%). VPA-treated mice also had increased embryolethality rates (52%). There was no significant change of embryolethality in the other treatment groups. Pharmacokinetic studies showed that VCD was eliminated from plasma at a slower rate than VPA. Also, the residual teratogenic activity of VPD was not accounted for by the relatively small amounts of its hydrolysis product VPA. This study indicates that VPD, VCA and VCD were distinctly less teratogenic than VPA. Apparently the amidation of the free carboxylic group and/or methyl-substitution at the beta-position of the carbon chain greatly decreased the teratogenic activity of VPA.

Prospective randomized comparison of laparoscopic ultrasonography using a flexible-tip ultrasound probe and intraoperative dynamic cholangiography during laparoscopic cholecystectomy.

BACKGROUND: We performed a prospective randomized comparison of laparoscopic intraoperative ultrasonography (LIOU) and dynamic intraoperative cholangiography (IOC) during laparoscopic cholecystectomy (LC). METHODS: LIOU and IOC were attempted in 518 consecutive patients scheduled for laparoscopic cholecystectomy. The order in which the diagnostic procedures were performed was randomly assigned. RESULTS: LIOU failed in two patients (0.4%), and there were 41 (7.9%) failed IOC. The common bile duct (CBD) was visualized reliably with both methods. Our patients showed sensitivities of 83.3% and 100% and specificities of 100% and 98.9%, with an overall accuracy of 99.2% and 98.9% for LIOU as compared to IOC for identifying unsuspected common bile duct stones. The time necessary for the examination was significantly shorter in LIOU than in IOC (7 versus 16 min). CONCLUSION: LIOU performed by experienced surgeons is a good and effective method to assess the CBD, including the neighboring structures of hepatoduodenal ligament. Using powerful, flexible-tip ultrasound probes, CBD exploration can be done in a longitudinal fashion, which is necessary for good anatomical clarity. A lack of adverse effects, shorter examination times, and lower costs are some of the advantages of this method. The most important advantage is the possibility of unlimited repetition, especially if there is difficulty identifying anatomic structures. In addition, there are some indications that LIOU has the potential to recognize major iatrogenic bile duct injuries.

Cell proliferation, migration and CAM-dependent neurite outgrowth as developmental in vitro endpoints for screening teratogenic potential: Application to valproic acid and related analogues of varying potency.

The in vivo teratogenic potential of valproic acid (VPA) and related teratogenic and non-teratogenic analogues has been correlated with their effects on specific in vitro endpoints of cell proliferation, migration and CAM-dependent neurite outgrowth, as these events are common to crucial epochs of development. The (+/-)-2-n-propyl-4-pentynoic acid [(+/-)-4-yn-VPA] and S-2-n-propyl-4-pentynoic acid [S(-)-4-yn-VPA] analogues increased the incidence of neural tube defects in mouse embryos exposed to a single dose, whereas the E-2-n-propyl-2-pentenoic acid (E-2-en-VPA) analogue and R-2-n-propyl-4-pentynoic acid [R( + )-4-yn-VPA] enantiomer were without effect. VPA and related analogues tested exerted comparable G1 phase antiproliferative effects in C6 glioma and limb bud cells in a dose range of 0-3 mM; however, their relative potency did not correlate with in vivo teratogenicity. In contrast, VPA and all teratogenic analogues, at 3 mM, inhibited neuronal cell aggregation and limb bud chondrocyte differentiation in a manner that exhibited a reasonable correlation with their in vivo teratogenicity. The teratogenic S(-)-4-yn-VPA and non-teratogenic R( + )-4-yn-VPA enantiomers exhibited a differential inhibition of primary neurone outgrowth of neuntes stimulated by cell adhesion molecules [L1 and N-cadherin (NCAD)]. Half-maximal inhibition was observed at approximately 150 muM for the teratogenic S(-)-4-yn-VPA enantiomer, but not the non-teratogenic R( + )-4-yn-VPA form. These results suggest that in vitro perturbations of differentiation are likely to provide the greatest discriminatory power for in vivo teratogenicity.

Incidence and risk factors for mitral valve prolapse in severe adolescent idiopathic scoliosis.

Mitral valve prolapse (MVP) is known to be associated with thoracic skeletal anomalies. To determine the incidence and risk factors for mitral valve prolapse in the adolescent population with severe idiopathic scoliosis (IS), a prospective follow-up study on 139 adolescent patients with IS from the Pediatric Orthopedic Service was undertaken. Data collected included age, sex, medical and family history, physical exam, electrocardiogram and echocardiogram, spinal x-rays, and pulmonary function tests. MVP was detected by echocardiogram in 13.6% (19/139) of patients with IS as compared with 3.2% in 154 age- and weight-matched controls (p < 0.006). All patients with MVP were asymptomatic and a systolic click or murmur was detected on the single preoperative exam only in 37% (7/19) of them. Patients with MVP and IS weighed less (45.1 +/- 2.0 vs 51.8 +/- 0.1 kg, p < 0.002) as compared with those IS patients without MVP. The electrocardiogram was abnormal in 21% (4/19) of patients with MVP as compared with only 1.6% (2/120) of patients with IS but no MVP. The two groups did not differ with respect to age at diagnosis, severity of scoliosis, positive family history of scoliosis, or the presence of restrictive lung disease. Though IS was more prevalent in females (79%), the presence of MVP was not related to gender. MVP was persistent in 10 of the 19 patients reevaluated by echocardiogram 2-4 years after spinal surgery. We conclude that MVP is four times more common in patients with severe IS than in the normal adolescent population, and is associated with a lower body weight in IS patients with MVP than in IS patients without MVP. The persistent nature of MVP, even after corrective spinal surgery, may be related to factors other than geometric changes of the heart caused by abnormal thoracic curvature.

Effects of lung preservation with Euro-Collins and University of Wisconsin solutions on endothelium-dependent relaxations.

BACKGROUND: This study compares the effect of lung preservation using flush perfusion of Euro-Collins or University of Wisconsin solution on the pulmonary vascular function of endothelium-dependent and endothelium-independent relaxations. METHODS: Rings of canine intrapulmonary arteries were studied after 6 hours of cold ischemia in Euro-Collins or University of Wisconsin preservation solution. Endothelium-dependent and endothelium-independent relaxations were induced in organ chamber experiments. To also study pulmonary resistance vessels, endothelium-dependent relaxations were induced in in vitro perfused intact rabbit lungs. RESULTS: In the organ chamber experiments, a moderate but significant (p < 0.05) reduction in endothelium-dependent relaxations were found in the perfused and stored vessels. In perfused rabbit lungs, a decrease in the endothelial response occurred immediately after perfusion with Euro-Collins solution. However, a recovery and overshooting response was found after preservation with either solution and 6 hours of cold ischemia. A significant increase in the sensitivity of smooth muscle cells to nitric oxide was shown in both preparations. CONCLUSIONS: Both crystalloid perfusion fluids cause a decrease in endothelial function during the perfusion procedure. In contrast, endothelial function is well preserved during the ischemic time. University of Wisconsin solution induced a higher sensitivity of the vascular smooth muscle to the endothelium-derived relaxing factor nitric oxide. A reduction in pulmonary vascular resistance after University of Wisconsin preservation may be of importance in subsequent clinical lung transplantation.

Do cyanobacteria swim using traveling surface waves?

Bacteria that swim without the benefit of flagella might do so by generating longitudinal or transverse surface waves. For example, swimming speeds of order 25 microns/s are expected for a spherical cell propagating longitudinal waves of 0.2 micron length, 0.02 micron amplitude, and 160 microns/s speed. This problem was solved earlier by mathematicians who were interested in the locomotion of ciliates and who considered the undulations of the envelope swept out by ciliary tips. A new solution is given for spheres propagating sinusoidal waveforms rather than Legendre polynomials. The earlier work is reviewed and possible experimental tests are suggested.

Methionine reduces the valproic acid-induced spina bifida rate in mice without altering valproic acid kinetics.

The antiepileptic drug valproic acid (VPA) is an established human teratogen causing spin bifida aperta. We recently developed a mouse model in which spina bifida aperta and occulta are induced with VPA. In a search for protection against neural tube defects, we investigated the effect of methionine on the incidence of VPA-induced spina bifida in the mouse. To induce spina bifida, we injected VPA (350 mg VPA-Na/kg body weight) subcutaneously three times on d 9 of gestation at 0, 6 and 12 h. In some mice, L-methionine (3 x 70 mg/kg body weight) was injected intraperitoneally 30 min before each VPA administration. When fetuses were examined on d 18, methionine treatment slightly reduced the VPA-induced spina bifida aperta rate from 5 to 1% (P > 0.05, no significant difference). The incidence of VPA-induced spina bifida occulta (90%) was significantly lower (28%) when methionine was also administered (P < 0.05). Examination on d 10 showed that the number of embryos in the mice administered VPA and methionine having an open neuroporus posterior was significantly lower than in mice administered VPA alone (P < 0.05). Pharmacokinetic studies indicated that VPA concentrations in maternal plasma and embryo did not differ between the two groups. Methionine reduces VPA-induced spina bifida in mice without altering VPA kinetics.

Identification of 9,13-dicis-retinoic acid as a major plasma metabolite of 9-cis-retinoic acid and limited transfer of 9-cis-retinoic acid and 9,13-dicis-retinoic acid to the mouse and rat embryos.

9-Cis-retinoic acid (9-cis-RA) has been proposed to be the endogenous ligand of retinoid X receptors. We examined the plasma pharmacokinetics of 9-cis-RA and its metabolites in nonpregnant female NMRI mice after oral dosing with 50 mg 9-cis-RA/kg body weight. Furthermore, we studied the metabolism of 9-cis-RA and its transfer to the embryo following oral administration of the precursor 9-cis-retinaldehyde (9-cis-RAL; 100 mg/kg body weight) to pregnant mice and rats on gestational days 11 and 13, respectively. Following 9-cis-RA administration, plasma levels of 9-cis-RA reached their maximum within 40-60 min and then declined in a monoexponential manner with an apparent half-life of 64 +/- 32 min. A great variety of polar metabolites of 9-cis-RA was found; among them, the beta-glucuronides of 9-cis-RA (9-cis-RAG) and of 9-cis-4-oxo-RA (9-cis-4-oxo-RAG) could be identified. A further prominent polar metabolite of 9-cis-RA in mouse plasma was shown to be an additional RA isomer (distinct from 13-cis-RA and all-trans-RA) whose concentrations weeesimilarly high as those of 9-cis-RA.(ABSTRACT TRUNCATED AT 250 WORDS)

Late follow-up after venous switch operation (Mustard procedure) for simple and complex transposition of the great arteries.

Most adolescents and young adults born with complete transposition of the great arteries (TGA) and alive today are survivors of the Mustard operation. This study reports on the serial, long-term (from 10 to > 20 years) follow-up of 85 patients who underwent this operation between 1971 and 1981. Of these, 63 had simple and 22 complex TGA. The age at surgery ranged from 2 days to 17 years. The early mortality rate was 10.5% and the late mortality 9.2%. The actuarial survival rate after 15 years was 86% for simple and 64% for complex TGA. Event-free survival after 15 years was 77% for simple and 46% for complex TGA. Yearly review of electrocardiograms and, less frequently, of Holter tracings disclosed a lower mean resting heart rate and decrease over time in sinus rhythm and an increase in active arrhythmias. Fifty-two percent had resting sinus rhythm and 17% had active arrhythmias at 16 to 20 years of follow-up. Exercise stress testing in 21 patients revealed resumption of sinus rhythm during exercise but significant diminution of endurance time and peak heart rate response. Seven of the survivors (9.2%) required reoperation. Of these, 4 had severe tricuspid regurgitation following patch closure of ventricular septal defect. This study shows gratifying long-term and event-free survival for the majority of patients who underwent surgery by this venous switch procedure.