Commensurate and incommensurate 1D interacting quantum systems

Single-atom imaging resolution of many-body quantum systems in optical lattices is routinely achieved with quantum-gas microscopes. Key to their great versatility as quantum simulators is the ability to use engineered light potentials at the microscopic level. Here, we employ dynamically varying microscopic light potentials in a quantum-gas microscope to study commensurate and incommensurate 1D systems of interacting bosonic Rb atoms. Such incommensurate systems are analogous to doped insulating states that exhibit atom transport and compressibility. Initially, a commensurate system with unit filling and fixed atom number is prepared between two potential barriers. We deterministically create an incommensurate system by dynamically changing the position of the barriers such that the number of available lattice sites is reduced while retaining the atom number. Our systems are characterised by measuring the distribution of particles and holes as a function of the lattice filling, and interaction strength, and we probe the particle mobility by applying a bias potential. Our work provides the foundation for preparation of low-entropy states with controlled filling in optical-lattice experiments.

Accurate holographic light potentials using pixel crosstalk modelling

Arbitrary light potentials have proven to be a valuable and versatile tool in many quantum information and quantum simulation experiments with ultracold atoms. Using a phase-modulating spatial light modulator (SLM), we generate arbitrary light potentials holographically with measured efficiencies between 15 and 40% and an accuracy of [Formula: see text] root-mean-squared error. Key to the high accuracy is the modelling of pixel crosstalk of the SLM on a sub-pixel scale which is relevant especially for large light potentials. We employ conjugate gradient minimisation to calculate the SLM phase pattern for a given target light potential after measuring the intensity and wavefront at the SLM. Further, we use camera feedback to reduce experimental errors, we remove optical vortices and investigate the difference between the angular spectrum method and the Fourier transform to simulate the propagation of light. Using a combination of all these techniques, we achieved more accurate and efficient light potentials compared to previous studies, and generated a series of potentials relevant for cold atom experiments.

Floquet Solitons and Dynamics of Periodically Driven Matter Waves with Negative Effective Mass

We experimentally study the dynamics of weakly interacting Bose-Einstein condensates of cesium atoms in a 1D optical lattice with a periodic driving force. After a sudden start of the driving, we observe the formation of stable wave packets at the center of the first Brillouin zone (BZ) in momentum space, and we interpret these as Floquet solitons in periodically driven systems. The wave packets become unstable when we add a trapping potential along the lattice direction, leading to a redistribution of atoms within the BZ. The concept of a negative effective mass and the resulting changes to the interaction strength and effective trapping potential are used to explain the stability and the time evolution of the wave packets. We expect that similar states of matter waves exist for discrete breathers and other types of lattice solitons in periodically driven systems.

Collisionally Inhomogeneous Bose-Einstein Condensates with a Linear Interaction Gradient

We study the evolution of a collisionally inhomogeneous matter wave in a spatial gradient of the interaction strength. Starting with a Bose-Einstein condensate with weak repulsive interactions in quasi-one-dimensional geometry, we monitor the evolution of a matter wave that simultaneously extends into spatial regions with attractive and repulsive interactions. We observe the formation and the decay of solitonlike density peaks, counterpropagating self-interfering wave packets, and the creation of cascades of solitons. The matter-wave dynamics is well reproduced in numerical simulations based on the nonpolynomial Schrödinger equation with three-body loss, allowing us to better understand the underlying behavior based on a wavelet transformation. Our analysis provides new understanding of collapse processes for solitons, and opens interesting connections to other nonlinear instabilities.

Excitation Modes of Bright Matter-Wave Solitons

We experimentally study the excitation modes of bright matter-wave solitons in a quasi-one-dimensional geometry. The solitons are created by quenching the interactions of a Bose-Einstein condensate of cesium atoms from repulsive to attractive in combination with a rapid reduction of the longitudinal confinement. A deliberate mismatch of quench parameters allows for the excitation of breathing modes of the emerging soliton and for the determination of its breathing frequency as a function of atom number and confinement. In addition, we observe signatures of higher-order solitons and the splitting of the wave packet after the quench. Our experimental results are compared to analytical predictions and to numerical simulations of the one-dimensional Gross-Pitaevskii equation.

Note: A simple laser shutter with protective shielding for beam powers up to 1 W

We present the design of an inexpensive and reliable mechanical laser shutter and its electronic driver. A camera diaphragm shutter unit with several sets of blades is utilized to provide fast blocking of laser light and protective shielding of the shutter mechanism up to a laser beam power of 1 W. The driver unit is based on an Arduino microcontroller with a motor-shield. Our objective was to strongly reduce construction effort and expenditure by limiting ourselves to a small number of modular parts, which are readily available. We measured opening and closing durations of less than 800 μs, and a timing jitter of less than 25 μs for the fastest set of blades. No degradation of the shutter performance was observed over 5·10⁴ cycles.

Iron modulates cell survival in a Ras- and MAPK-dependent manner in ovarian cells

Ovarian cancer is a leading cause of cancer death in women in the United States. While the majority of ovarian cancers are serous, some rarer subtypes (i.e. clear cell) are often associated with endometriosis, a benign gynecological disease. Iron is rich in the cyst fluid of endometriosis-associated ovarian cancers and induces persistent oxidative stress. The role of iron, an essential nutrient involved in multiple cellular functions, in normal ovarian cell survival and ovarian cancer remains unclear. Iron, presented as ferric ammonium citrate (FAC), dramatically inhibits cell survival in ovarian cancer cell types associated with Ras mutations, while it is without effect in immortalized normal ovarian surface epithelial (T80) and endometriotic epithelial cells (lacking Ras mutations). Interestingly, FAC induced changes in cytoplasmic vacuolation concurrently with increases in LC3-II levels (an autophagy marker); these changes occurred in an ATG5/ATG7-dependent, beclin-1/hVps34-independent, and Ras-independent manner. Knockdown of autophagy mediators in HEY ovarian cancer cells reversed FAC-induced LC3-II levels, but there was little effect on reversing the cell death response. Intriguingly, transmission electron microscopy of FAC-treated T80 cells demonstrated abundant lysosomes (confirmed using Lysotracker) rich in iron particles, which occurred in a Ras-independent manner. Although the mitogen-activated protein kinase (MAPK) inhibitor, U0126, reversed FAC-induced LC3-II/autophagic punctae and lysosomes in a Ras-independent manner, it was remarkable that U0126 reversed cell death in malignant ovarian cells associated with Ras mutations. Moreover, FAC increased heme oxygenase-1 expression in H-Ras-overexpressing T80 cells, which was associated with increased cell death when overexpressed in T80 cells. Disruption of intracellular iron levels, via chelation of intracellular iron (deferoxamine), was also detrimental to malignant ovarian cell survival; thus, homeostatic intracellular iron levels are essential for cell survival. Collectively, our results implicate iron in modulating cell death in a Ras- and MAPK-dependent manner in ovarian cancer cells.

Preparation and spectroscopy of a metastable Mott-insulator state with attractive interactions

We prepare and study a metastable attractive Mott-insulator state formed with bosonic atoms in a three-dimensional optical lattice. Starting from a Mott insulator with Cs atoms at weak repulsive interactions, we use a magnetic Feshbach resonance to tune the interactions to large attractive values and produce a metastable state pinned by attractive interactions with a lifetime on the order of 10 s. We probe the (de)excitation spectrum via lattice modulation spectroscopy, measuring the interaction dependence of two- and three-body bound-state energies. As a result of increased on-site three-body loss we observe resonance broadening and suppression of tunneling processes that produce three-body occupation.

Three-body correlation functions and recombination rates for bosons in three dimensions and one dimension

We investigate local three-body correlations for bosonic particles in three dimensions and one dimension as a function of the interaction strength. The three-body correlation function g(3) is determined by measuring the three-body recombination rate in an ultracold gas of Cs atoms. In three dimensions, we measure the dependence of g(3) on the gas parameter in a BEC, finding good agreement with the theoretical prediction accounting for beyond-mean-field effects. In one dimension, we observe a reduction of g(3) by several orders of magnitude upon increasing interactions from the weakly interacting BEC to the strongly interacting Tonks-Girardeau regime, in good agreement with predictions from the Lieb-Liniger model for all strengths of interaction.

Precision measurements on a tunable Mott insulator of ultracold atoms

We perform precision measurements on a Mott-insulator quantum state of ultracold atoms with tunable interactions. We probe the dependence of the superfluid-to-Mott-insulator transition on the interaction strength and explore the limits of the standard Bose-Hubbard model description. By tuning the on-site interaction energies to values comparable to the interband separation, we are able to quantitatively measure number-dependent shifts in the excitation spectrum caused by effective multibody interactions.

Inducing transport in a dissipation-free lattice with super Bloch oscillations

Particles in a perfect lattice potential perform Bloch oscillations when subject to a constant force, leading to localization and preventing conductivity. For a weakly interacting Bose-Einstein condensate of Cs atoms, we observe giant center-of-mass oscillations in position space with a displacement across hundreds of lattice sites when we add a periodic modulation to the force near the Bloch frequency. We study the dependence of these "super" Bloch oscillations on lattice depth, modulation amplitude, and modulation frequency and show that they provide a means to induce linear transport in a dissipation-free lattice.

Confinement-induced resonances in low-dimensional quantum systems

We report on the observation of confinement-induced resonances in strongly interacting quantum-gas systems with tunable interactions for one- and two-dimensional geometry. Atom-atom scattering is substantially modified when the s-wave scattering length approaches the length scale associated with the tight transversal confinement, leading to characteristic loss and heating signatures. Upon introducing an anisotropy for the transversal confinement we observe a splitting of the confinement-induced resonance. With increasing anisotropy additional resonances appear. In the limit of a two-dimensional system we find that one resonance persists.

Control of interaction-induced dephasing of Bloch oscillations

We report on the control of interaction-induced dephasing of Bloch oscillations for an atomic Bose-Einstein condensate in an optical lattice. We quantify the dephasing in terms of the width of the quasimomentum distribution and measure its dependence on time for different interaction strengths which we control by means of a Feshbach resonance. For minimal interaction, the dephasing time is increased from a few to more than 20 thousand Bloch oscillation periods, allowing us to realize a BEC-based atom interferometer in the noninteracting limit.

Bose-Einstein condensates: microscopic magnetic-field imaging

Today's magnetic-field sensors are not capable of making measurements with both high spatial resolution and good field sensitivity. For example, magnetic force microscopy allows the investigation of magnetic structures with a spatial resolution in the nanometre range, but with low sensitivity, whereas SQUIDs and atomic magnetometers enable extremely sensitive magnetic-field measurements to be made, but at low resolution. Here we use one-dimensional Bose-Einstein condensates in a microscopic field-imaging technique that combines high spatial resolution (within 3 micrometres) with high field sensitivity (300 picotesla).

Identification of a novel lipopolysaccharide-inducible gene with key features of both A kinase anchor proteins and chs1/beige proteins

Mutations in chs1/beige result in a deficiency in intracellular transport of vesicles that leads to a generalized immunodeficiency in mice and humans. The function of NK cells, CTL, and granulocytes is impaired by these mutations, indicating that polarized trafficking of vesicles is controlled by CHS1/beige proteins. However, a molecular explanation for this defect has not been identified. Here we describe a novel gene with orthologues in mice, humans, and flies that contains key features of both chs1/beige and A kinase anchor genes. We designate this novel gene lba for LPS-responsive, beige-like anchor gene. Expression of lba is induced after LPS stimulation of B cells and macrophages. In addition, lba is expressed in many other tissues in the body and has three distinct mRNA isoforms that are differentially expressed in various tissues. Strikingly, LBA-green-fluorescent protein (GFP) fusion proteins are localized to vesicles after LPS stimulation. Confocal microscopy indicates this protein is colocalized with the trans-Golgi complex and some lysosomes. Further analysis by immunoelectron microscopy demonstrates that LBA-GFP fusion protein can localize to endoplasmic reticulum, plasma membrane, and endocytosis vesicles in addition to the trans-Golgi complex and lysosomes. We hypothesize that LBA/CHS1/BG proteins function in polarized vesicle trafficking by guiding intracellular vesicles to activated receptor complexes and thus facilitate polarized secretion and/or membrane deposition of immune effector molecules.

Comparison of different biomaterials for glaucoma drainage devices: part 2

BACKGROUND

Inflammation associated with biomaterials may contribute to the failure of glaucoma drainage devices.

OBJECTIVE

To compare the inflammatory reaction associated with the insertion of Krupin silicone, Molteno polypropylene, and Acrosof end plates in the subconjunctival space of rabbits.

METHODS

Similar-sized glaucoma end plates made of 3 different biomaterials were sutured to the sclera in the superotemporal quadrant of the rabbit eye. Thirty eyes of 15 albino New Zealand rabbits were randomly assigned to the 3 groups. Conjunctival vascular hyperemia was graded in a masked fashion among the 3 groups. At the end of 3 weeks, the enucleated eyes were examined histologically and by scanning electron microscopy.

RESULTS

Molteno polypropylene was associated with more inflammation both in clinical observations and based on histological grading. Silicone and Acrosof were associated with less intense inflammation. One polypropylene end plate was extruded on day 21.

CONCLUSIONS

Polypropylene appears to be more inflammatory than silicone. Flexible biomaterials appear to be less inflammatory than rigid ones.

CLINICAL RELEVANCE

Bleb failure following glaucoma drainage device implantation could be related to the biomaterial-associated inflammation. Choosing a biomaterial with the least inflammatory potential might enhance the success rate of the glaucoma drainage device. Arch Ophthalmol. 2000;118:1081-1084

Quadrupole Effects on 73Ge NMR Spectra in Isotopically Controlled Ge Single Crystals

NMR spectra of 73Ge (nuclear spin I = 9/2) in perfect single crystals of germanium with different isotopic content were measured at 80, 300, and 450 K. The observed specific line shapes gave evidence of the isotopic disorder, in particular, abnormal broadening of the spectrum was found for the magnetic field directed along the [111] axis. Local lattice deformations in the germanium crystal lattice due to "isotopic disorder" were calculated in the framework of the adiabatic bond charge model. The results were applied to study random non-cubic crystal field interactions with the nuclear quadrupole moments and corresponding effects on NMR spectra. The simulated second moment of the resonance frequency distributions caused by the magnetic dipole-dipole and electric quadrupole interactions are used to analyze the lineshapes, theoretical predictions being in a qualitative agreement with the experimental data.

Comparison of different biomaterials for glaucoma drainage devices

OBJECTIVES

To compare the inflammatory reaction associated with the insertion of silicone and polypropylene endplates and endplates made of a new biocompatible polymer, Vivathane, in the rabbit subconjunctival space.

METHODS

Similar-sized endplates made of 3 different biomaterials were sutured to the sclera in the superotemporal quadrant of the rabbit eye. Thirty eyes of 15 albino New Zealand rabbits were randomly assigned to the 3 groups. Conjunctival vascular hyperemia was graded in a masked fashion among groups. At the end of 3 weeks, the enucleated eyes were examined histologically and using scanning electron microscopy.

RESULTS

Polypropylene and Vivathane were associated with significantly more inflammation in clinical observations and based on histological grading. Silicone was associated with the least amount of inflammation. Three polypropylene and 1 Vivathane plate were extruded between the second and third week.

CONCLUSIONS

Silicone is the most inert of the 3 materials tested. Inflammation associated with biomaterials may contribute to the failure of the glaucoma drainage devices.

CLINICAL RELEVANCE

Bleb inflammation may be related to the biomaterial being used as the endplate. Endplates should be handled carefully during surgery to avoid creating rough spots.

Purification and characterization of a phytase from Klebsiella terrigena

A cytoplasmatic phytase was purified about 410-fold to apparent homogeneity with a recovery of 28%. The enzyme is induceable under carbon limitation in the presence of phytate. It behaves as a monomeric protein of a molecular mass of about 40 kDa. The phytase is rather specific for phytate and exhibits optimal conditions for phytate degradation at pH 5.0 and 58 degrees C. Kinetic parameters for the hydrolysis of Na phytate are KM 300 microM and kcat 180 s-1 at 35 degrees C and pH 5.0. Phytate is hydrolyzed in a stepwise manner; the penta- and tetrakisphosphate were identified as I(1,2,4,5,6)P5 and I(1,2,5,6)P4. Consequently, this enzyme is a 3-phytase (EC 3.1.3.8).

Propranolol as an adjunct therapy for hyperthyroid tremor

We evaluated the use of propranolol as an adjunct to carbimazole in the treatment of hyperthyroid tremor and tachycardia in a double-blind, cross-over and placebo-controlled study. Seven patients were given carbimazole plus either placebo or propranolol (40 mg) for 1 month and then switched to the alternative adjunct treatment for a further month. All patients showed significant improvements (p < 0.001) of heart rate and tremor amplitude after 1 or 2 months from baseline. One month after the baseline, the mean improvements of heart rate were 23% for the carbimazole + placebo group and 38% for carbimazole + propranolol group. Tremor also improved during the 1st month of the study by 31% in the carbimazole + placebo group versus 59% in the carbimazole + propranolol group. Whereas further improvements were observed in both variables in those receiving propranolol as the second adjunct treatment, this was not the case in those who received placebo during the same period. These findings confirm that the beta-blocker propranolol is a useful adjunct in the early treatment of both the tremor and tachycardia of hyperthyroidism.

Impact of a smoking ban on a locked psychiatric unit

BACKGROUND

This study prospectively evaluated the impact of a complete smoking ban on a locked psychiatric unit.

METHOD

The setting was a 16-bed inpatient unit with 83% (134/162) involuntary patients, no off-unit smoking area, no possibility of granting smoking passes, and a mean length of stay of 2 weeks. The effect of a complete smoking ban was measured by surveys of both staff and patients before and after the ban. In addition, objective indicators of ward disruption were measured, including rates of aggression, use of p.r.n. medications, need for seclusion and restraints, elopement, and discharges against medical advice.

RESULTS

Although staff initially expressed concern about the ban's potential negative impact, after it began, t tests revealed that staff were significantly (p < .05) less concerned about patients' needing more medication, becoming restless, being too fragile to cope with withdrawal, leaving the unit against medical advice, or trying to elope. Staff were significantly (p < .02) more positive about the ban than were patients. Although patients, overall, had negative views toward the new policy, their opinions were somewhat less negative after its implementation. Rates of assaultive behavior, use of seclusion and restraints, use of p.r.n. medication, and against-medical-advice or elopement discharges did not change after the ban was in effect. When polled, 78% (40/51) of the staff voted to keep the ban.

CONCLUSION

This study found that staff anticipated negative consequences to a total smoking ban; however, their attitudes changed after it began. The ban had no significant impact on the ward milieu, and although patients were not in favor of it, they felt less negative over time.

Botulinum toxin A in non-dystonic tremors

The present pilot study evaluated the effect of botulinum toxin A on primarily non-dystonic tremors using accelerometry in a single-blind, placebo-controlled design. Resting, postural, intention, or head tremor were assessed before and approximately 1 month after intramuscular saline and botulinum toxin A (25-50 U) respectively. Half of the patients showed > or = 30% placebo effect. Tremor in 10 of 17 patients (60%) studied improved further after botulinum toxin A (range 30-95%), exceeding the placebo effect by > or = 30%. Nine patients demonstrated clinically significant focal weakness in the extensor muscles after botulinum toxin A which interfered with fine movements. Patients were subdivided into PD-like and ET-like tremor(s). Both groups experienced large placebo effects for resting tremor, with little or no further improvement after botulinum toxin A. The improvement in postural tremor after botulinum toxin A, of 40% in the PD-like and 57% in the ET-like groups, however, was approximately twice that of placebo. In conclusion, botulinum toxin A exerts a modest tremorlytic effect, however the dose, and its distribution over the sites injected, need to be optimised to minimise focal weakness.

In situ effects of interferon on human glioma protein kinase C-alpha and -beta ultrastructural localization

Transmission electron microscopy was used to determine how immunogold labeling of PKC-alpha or -beta is modulated by the antitumor drug IFN (HuIFN alpha-2b) in the cytoplasm, membrane structures, and nucleus of rapidly dividing and confluent human glioma U-373 cells. Results showed that except for nuclear localization, there were no specific cytoplasmic organelles that PKC-alpha or -beta translocated to following HuIFN alpha-2b treatment. Electron micrographs of PKC-beta in proliferating cells depicted 1.34-fold more PKC-beta in the nucleus than in the cytoplasm and a 1-min HuIFN alpha-2b (500 units/ml) treatment transiently increased PKC-beta immunoreactivity in the cytoplasm (1.95-fold) and nucleus (1.97-fold). In confluent cells, incubation with HuIFN alpha-2b for 2 min significantly decreased cytoplasmic PKC-beta immunoreactivity by 37%, and no change was observed in nuclear PKC-beta labeling. PKC-alpha labeling in proliferating cells showed similar immunoreactivity in both control cytoplasm and nucleus. Treatment of proliferating cells with HuIFN alpha-2b for 2 min decreased PKC-alpha in the cytoplasm (59%) and nucleus (44%). In confluent cells, cytoplasmic PKC-alpha labeling decreased 59% at 1 min, 61% at 2 min, and 76% at 10 min of HuIFN alpha-2b treatment. Nuclear PKC-alpha decreased by 65% at 1 min, 80% at 2 min, and 62% at 10 min after HuIFN alpha-2b treatment. Western blots of total PKC-alpha in proliferating and confluent cells and PKC-beta in confluent cells showed similar results. However, Western blots of total PKC-alpha and -beta in proliferating cells did not demonstrate any significant changes in either PKC-alpha or -beta immunoreactivity following 1-min HuIFN alpha-2b treatment. These results suggest that treatment of proliferating U-373 cells with HuIFN alpha-2b for 1 min unfolds and exposes PKC-beta antigenic sites (hinge region) and increases in situ PKC-beta immunogold labeling.

Prediction of 18-month survival in patients with primary myelodysplastic syndrome. A regression model and scoring system based on the combination of chromosome findings and the Bournemouth score

The predictive potential of six selected factors was assessed in 72 patients with primary myelodysplastic syndrome using univariate and multivariate logistic regression analysis of survival at 18 months. Factors were age (above median of 69 years), dysplastic features in the three myeloid bone marrow cell lineages, presence of chromosome defects, all metaphases abnormal, double or complex chromosome defects (C23), and a Bournemouth score of 2, 3, or 4 (B234). In the multivariate approach, B234 and C23 proved to be significantly associated with a reduction in the survival probability. The similarity of the regression coefficients associated with these two factors means that they have about the same weight. Consequently, the model was simplified by counting the number of factors (0, 1, or 2) present in each patient, thus generating a scoring system called the Lausanne-Bournemouth score (LB score). The LB score combines the well-recognized and easy-to-use Bournemouth score (B score) with the chromosome defect complexity, C23 constituting an additional indicator of patient outcome. The predicted risk of death within 18 months calculated from the model is as follows: 7.1% (confidence interval: 1.7-24.8) for patients with an LB score of 0, 60.1% (44.7-73.8) for an LB score of 1, and 96.8% (84.5-99.4) for an LB score of 2. The scoring system presented here has several interesting features. The LB score may improve the predictive value of the B score, as it is able to recognize two prognostic groups in the intermediate risk category of patients with B scores of 2 or 3. It has also the ability to identify two distinct prognostic subclasses among RAEB and possibly CMML patients. In addition to its above-described usefulness in the prognostic evaluation, the LB score may bring new insights into the understanding of evolution patterns in MDS. We used the combination of the B score and chromosome complexity to define four classes which may be considered four possible states of myelodysplasia and which describe two distinct evolutional pathways.

[Motility disorders in brachytherapy of choroid melanomas with Ru106 applicators]

Accurate visualization of the tumor base by diaphanoscopy is essential for optimal placement of a ruthenium plaque. Depending on the localization of the tumor, dissection of one or more of the rectus muscles is necessary during placement of the plaque or during the course of protracted irradiation. Orthoptic investigations were performed to evaluate the cause of motility disorders and to follow up the functional outcome. In 13 patients (out of 30) who underwent ruthenium-106 therapy for uveal melanomas, one or more muscles had to be dissected during placement of the plaque and were reinserted in the same operation or after removal of the applicator. In 4 cases rectus muscles had to be shifted and were replaced after the irradiation. There were 5 patients who developed motility disorders with double vision. All of them were orthophoric within 6 months without surgery.

Hematologic, clinical, and cytogenetic analysis in 109 patients with primary myelodysplastic syndrome. Prognostic significance of morphology and chromosome findings

One hundred and nine patients with primary myelodysplastic syndrome (MDS) were classified according to the French-American-British (FAB) criteria: 27 refractory anemia (RA, 25%), 26 RA with ringed sideroblasts (RARS, 24%), 16 RA with excess of blasts (RAEB, 15%), 10 RAEB in transformation (RAEB-t, 9%), 25 chronic myelomonocytic leukemia (CMMoL, 23%), and five unclassifiable MDS (4%). Forty-three were women and 66 were men (sex ratio 2:3). Age ranged from 30-92 years (mean 69 years) with nine patients aged less than 50 years (8%). A cytogenetic result was obtained in all cases. At initial study, a chromosome defect was observed in 56% of patients. Rates of abnormality depended on FAB subtype: 52% in RA, 100% in RA 5q-, 50% in RARS, 56% in RAEB, 70% in RAEB-t and 44% in CMMoL. The most frequent single defects were del(5q), -7/del(7q), del(20q), Y loss, and +8. Except for the 5q- syndrome entity, specific chromosome defects were not associated with particular FAB subtypes. Bone marrow (BM) insufficiency (22%) and leukemic transformation (21%) were the most important causes of death. The rate of leukemic transformation increased with the number of dysplastic BM cell lineages and was also associated with karyotype complexity and the proportion of abnormal/normal metaphases. The longest median survivals were observed in RARS (142 months) and RA/RA5q- (91 months) types. Median survivals decreased with increasing Bournemouth score values. Patients with three abnormal cell lineages had a median survival shorter than those with one or two abnormal lineages. Similarly, patients with complex defects had shorter survival than those with single or double defects or a normal karyotype. There was no statistically significant difference between survival of NN (normal), AN (abnormal/normal), and AA patients or between survival of patients with del(5q), -7/del(7q), +8 or del(20q).

IgE to food allergens are highly prevalent in patients allergic to pollens, with and without symptoms of food allergy

Serum samples from 274 patients allergic to one or more of three pollens (birch, grass, mugwort), from 36 patients allergic to cat and/or Dermatophagoides pteronyssinus but not to pollen and from 55 non-allergic controls, as well as 20 cord blood samples, were examined for specific IgE to six 'pollen-associated' food allergens by using a new sensitive assay (CAP). A questionnaire asking for reactions to food was also sent to all patients. In the pollen group, 111 patients (47%) were positive (> or = 0.71 kU/l) for a food allergen (392 positive tests). Of these, 92 were sensitive to apple, 68 to potato, 64 to carrot, 63 to celery, 61 to peach and 44 to melon. In the non-allergic group, no IgE to any of the food allergens tested was found, whereas in the group allergic to non-pollen allergens, only one individual had such an IgE. The CAP assay was found to be more sensitive than RAST for the allergens studied. A history of clinical reactions (oral symptoms in 67, rhinoconjunctivitis in 65, asthma in 42 and urticaria in 39) to the corresponding food allergen was reported mainly by patients with positive CAP. In conclusion, we found a high prevalence of IgE to some food allergens in patients allergic to pollen and the absence of such antibodies in the control groups. The new in vitro assay, being more sensitive than previous ones, indicated a high prevalence of food specific IgE in pollen allergic patients, which in many cases did not correspond to clinical symptoms of food allergy.

Successful management of patients with "multiple chemical sensitivities" on an inpatient psychiatric unit

BACKGROUND

Much controversy exists over the diagnosis, etiology, and treatment of "multiple chemical sensitivities" also known as "environmental illness." The experience of multiple nonspecific reactions to numerous environmental agents leads to these diagnoses. Due to skepticism surrounding the validity of these patients' complaints, they are often referred for psychiatric evaluations, but successful management on a psychiatric inpatient unit can be complicated because of their unique presentations.

METHOD

The approach taken by a university psychiatric inpatient unit to the evaluations of three such patients is presented along with a literature review of etiologic theories and treatment recommendations.

RESULTS

Each of the three patients presented with severe disability from their "sensitivities," but each improved significantly over the course of a 17-day hospitalization.

CONCLUSION

These patients benefited greatly from a serious, nonjudgmental, comprehensive approach to the evaluation of their multiple complaints. Despite the absence of any positive organic findings, each felt that her experiences had been validated, and each subsequently improved. When evaluating similar patients, clinicians should be aware of useful, effective management strategies and should avoid overt skepticism and confrontation.

Eating disorders. A review and update

Anorexia nervosa and bulimia nervosa are prevalent illnesses affecting between 1% and 10% of adolescent and college age women. Developmental, family dynamic, and biologic factors are all important in the cause of this disorder. Anorexia nervosa is diagnosed when a person refuses to maintain his or her body weight over a minimal normal weight for age and height, such as 15% below that expected, has an intense fear of gaining weight, has a disturbed body image, and, in women, has primary or secondary amenorrhea. A diagnosis of bulimia nervosa is made when a person has recurrent episodes of binge eating, a feeling of lack of control over behavior during binges, regular use of self-induced vomiting, laxatives, diuretics, strict dieting, or vigorous exercise to prevent weight gain, a minimum of 2 binge episodes a week for at least 3 months, and persistent overconcern with body shape and weight. Patients with eating disorders are usually secretive and often come to the attention of physicians only at the insistence of others. Practitioners also should be alert for medical complications including hypothermia, edema, hypotension, bradycardia, infertility, and osteoporosis in patients with anorexia nervosa and fluid or electrolyte imbalance, hyperamylasemia, gastritis, esophagitis, gastric dilation, edema, dental erosion, swollen parotid glands, and gingivitis in patients with bulimia nervosa. Treatment involves combining individual, behavioral, group, and family therapy with, possibly, psychopharmaceuticals. Primary care professionals are frequently the first to evaluate these patients, and their encouragement and support may help patients accept treatment. The treatment proceeds most smoothly if the primary care physician and psychiatrist work collaboratively with clear and frequent communication.

[Ozone, ventilatory function and bronchial reactivity]

Forty adult hospital workers were followed prospectively in 1989 by monthly assessment of the lung function and bronchial responsiveness to methacholine in a rural region in Switzerland. No correlation was demonstrated between these values and the concentrations of tropospheric ozone. Nevertheless, this is not incompatible with previous studies showing impairment of ventilatory function in subjects exposed to ozone, for several reasons: ozone levels in 1989 were low, the indoor concentrations were lower than outdoors and the volunteers performed little or no physical activity.

Obstetric complications in a patient with Bernard-Soulier syndrome

We describe the obstetric complications and management of a patient with Bernard-Soulier syndrome. Severe bleeding at the time of delivery and delayed postpartum hemorrhage were prominent features of her pregnancies. Further complicating this woman's pregnancies was the development of antibodies to platelet glycoprotein IB/IX, leading to neonatal alloimmune thrombocytopenia.

Clozapine and seizures

Clozapine is a newly released antipsychotic that is associated with a higher prevalence of seizures than traditional neuroleptics. The authors describe four patients who developed seizure activity during clozapine treatment and provide recommendations for clinical management of this problem.

Clozapine--a new and different neuroleptic

These discussions are selected from the weekly staff conferences in the Department of Medicine, University of California, San Francisco. Taken from a transcription, it has been edited by Homer A. Boushey, MD, Professor of Medicine, and Nathan M. Bass, MD, PhD, Associate Professor of Medicine, under the direction of Lloyd H. Smith, Jr, MD, Professor of Medicine and Associate Dean in the School of Medicine.

Right arm involvement and pain extension can help to differentiate coronary diseases from chest pain of other origin: a prospective emergency ward study of 278 consecutive patients admitted for chest pain

In a prospective study of 278 consecutive patients admitted to an emergency ward for chest pain, the 115 clinical and paraclinical parameters available at the time of admission were evaluated by computer comparison with the final diagnoses. The most valuable items for making the diagnosis were classified according to their sensitivity, specificity and predictive value. Among the 278 patients, 100 individuals had myocardial infarctions (MI), 47 had unstable angina, 25 had stable angina and 106 patients had a non-coronary disease. The twelve most sensitive items for distinguishing MI from other conditions were the following: sudden onset of pain (70%); duration of more than 60 min (88%); constriction and squeezing (79%); oppression (75%); prior anginal attacks (61%); sex male (72%); age over 60 years (74%); abnormal heart auscultation (62%); abnormal electrocardiogram (ECG) (98%); segment (ST) disturbances (86%); increased glucose level (77%); CKMB fraction greater than 6% of total creatine kinase (CK) level (63%). Among the twelve most specific items, also with the best positive predictive value, irradiation in the right arm is of most importance; among the 51 patients with right arm involvement, 48 suffered from a coronary disease and 41 from a myocardial infarction. The largest extension of pain was reported in the latter group. It is concluded that chest pain with a wide irradiation involving the right arm strongly suggests that a myocardial infarction is ongoing.

[Current role of biopsy in the diagnosis of hepatic disease]

The criteria for the use of liver biopsy as a diagnostic tool were retrospectively analyzed over a ten-year period in 390 consecutive patients. The four principal conditions in which this procedure was employed were alcoholism (33%), hepatitis (18%), abnormal hepatic tests (16%) and tumors (10%). The development of new, "non-invasive", investigative methods such as echography and tomodensitometry has led to an decrease in the number of liver biopsies performed annually, but no change in the relative frequency of the various indications. In this paper, evidence is presented which demonstrates that hepatic biopsy confirmed the clinical diagnosis in 62.4% of the cases reviewed and fundamentally modified the diagnosis in 20.2%. Based upon these findings, it can be concluded that liver biopsy remains an indispensable diagnostic procedure in the field of hepatology, since it can result in modification of the clinician's diagnosis in one out of five cases.

Adjusted subcutaneous heparin versus heparin plus dihydroergotamine in prevention of deep vein thrombosis after total hip arthroplasty

In a prospective randomized study, two different antithrombotic regimens were compared with regard to their effects on the incidence of deep vein thrombosis (DVT) in 102 patients undergoing elective total hip arthroplasty. Fifty patients (group 1) received heparin subcutaneously three times daily in doses adjusted as a function of activated partial thromboplastin time (APTT), and 52 patients (group 2) received a fixed dose of 5,000 IU heparin plus 0.5 mg dihydroergotamine twice daily. Both treatments were started 2 days before operation and continued for 7-9 days after operation, when venography of the operated leg was performed in all patients. The overall incidence of DVT was 22% in group 1 and 19.6% in group 2. Eight patients (16%) in group 1 and four (7.6%) in group 2 developed proximal DVT. These differences were not statistically significant. Hemorrhagic complications occurred more frequently in group 1. Heparin plus dihydroergotamine is a simple and effective method of preventing DVT in patients undergoing total hip arthroplasty. Daily APTT-adjusted subcutaneous heparin remains the best method of prevention of DVT in patients with contraindications to the use of dihydroergotamine and those with two or more DVT risk factors.

[Prognostic value of the renin-angiotensin system in response to salt restriction and prognosis of alcoholic ascitic cirrhosis]

Prognostic factors in alcoholic cirrhosis with ascites were analyzed in a prospective study of 37 patients (25 men, 12 women), 26 of whom presented with clinically diagnosed ascites. A good therapeutic response following salt restriction was obtained in 50%; this response correlated well with an initially small ascites volume, male sex, daily urinary sodium excretion of greater than 10 mmol, plasma renin activity of less than 5 ng/ml/hr and a normal plasma aldosterone level. On the other hand, age, number of episodes and duration of ascites, hepatic functional parameters, plasma creatinine concentration and portal venous pressure had no predictive value as to therapeutic response. Patients' survival was inversely related to plasma renin activity and positively to sodium excretion. The one-year mortality rate reached 88% in patients with renin of greater than 5 ng/ml/hr or daily urinary sodium excretion of less than 10 mmol, while 70% of patients with renin of less than 5 ng/ml/hr or daily sodium excretion of greater than 10 mmol survived more than two years. No prognostic index of survival could be derived from age, sex, number of episodes, duration and volume of ascites, portal venous pressure or hepatic biochemical parameters. Thus, in cirrhotic alcoholic patients with ascites the determination of daily urinary sodium excretion, which is inversely related to the activity of the renin-angiotensin system, provides a useful prognostic index for the response to salt restriction and longterm survival.