Longitudinal Cognitive Decline in Patients With Mild Cognitive Impairment or Dementia Due to Alzheimer's Disease

Sensitive cognitive assessments accurately detect and track cognitive decline in Alzheimer's disease. The Cogstate battery was used to measure cognitive change in cognitively normal participants and in individuals with mild cognitive impairment and mild Alzheimer's disease enrolled in the Australian Imaging, Biomarker and Lifestyle Rate of Change Substudy. Over 18 months, verbal episodic memory performance declined for mild cognitive impairment and mild Alzeheimer's disease groups when compared to cognitively normal participants. Frequent assessments of episodic memory may facilitate early detection of cognitive decline due to Alzheimer's disease.

A double-sided fabrication process for intrafascicular parylene C based electrode arrays

After the development of a single-sided fabrication process for intrafascicular parylene C based electrode arrays tests showed that an increase in integration density can only be achieved by a double-side process. The process uses 25 μm thick platinum iridium foil, which is thinned down with the laser and sandwiched between two 10 μm thick parylene C layers. Utilizing a picosecond laser (355 nm Nd:YVO4) it was possible to fabricate 40 μm thick electrodes that can be implanted directly in the nerve without relying on additional support layers like chitosan or silk. The fabricated samples feature three 80 μm diameter electrodes on each side and a large ground electrode that is opened to both sides. Impedance mismatches from front to back side as a result of the fabrication process are compensated by electrochemical deposition of nanostructured platinum. This step makes it possible to bring the impedances of the small electrodes down to the range of just a few kΩ at 1 kHz and illustrate the additionally gained surface due to the picosecond laser ablation on the front side electrodes. The safely injectable charge per pulse was found to be 635.75 μC/cm2 for such coated electrodes. Optical investigations show that this fabrication process offers an alternative to established lithographic processes for thin and flexible electrode arrays in neural implants.

Psychometric evaluation of ADAS-Cog and NTB for measuring drug response

AIMS

To conduct a psychometric analysis to determine the adequacy of instruments that measure cognition in Alzheimer's disease trials.

BACKGROUND

Both the Alzheimer's Disease Assessment Scale - Cognition (ADAS-Cog) and the Neuropsychological Test Battery (NTB) are validated outcome measures for clinical trials in Alzheimer's disease and are approved also for regulatory purposes. However, it is not clear how comparable they are in measuring cognitive function. In fact, many recent trials in Alzheimer's disease patients have failed and it has been questioned if ADAS-Cog still is a sensitive measure.

MATERIALS AND METHODS

The present paper examines the psychometric properties of ADAS-Cog and NTB, based on a post hoc analysis of data from a clinical trial (NCT01024660), which was conducted by AstraZeneca, in mild-to-moderate Alzheimer's disease (AD) patients, with a Mini Mental State Examination (MMSE) Total score 16-24. Acceptability, reliability, different types of validity and ability to detect change were assessed using relevant statistical methods. Total scores of both tests, as well as separate domains of both tests, including the Wechsler Memory Scale (WMS), Rey Auditory Verbal Learning Test (RAVLT) and Delis-Kaplan Executive Function System (D-KEFS) Verbal Fluency Condition, were analyzed.

RESULTS

Overall, NTB performed well, with acceptable reliability and ability to detect change, while ADAS-Cog had insufficient psychometric properties, including ceiling effects in 8 out of a total of 11 ADAS-Cog items in mild AD patients, as well as low test-retest reliability in some of the items.

DISCUSSION

Based on a direct comparison on the same patient sample, we see advantages of the NTB compared with the ADAS-Cog for the evaluation of cognitive function in the population of mild-to-moderate AD patients. The results suggest that not all of ADAS-Cog items are relevant for both mild and moderate AD population.

CONCLUSIONS

This validation study demonstrates satisfactory psychometric properties of the NTB, while ADAS-Cog was found to be psychometrically inadequate.

[Elderly prostate cancer patients: patient information and shared decision making]

INTRODUCTION

Some data exist on information and decision-making preferences of elderly prostate cancer patients but little is known about whether communication needs are being met in urological practice. Therefore, it was the aim of this study to examine the information and shared decision-making experiences of prostate cancer patients over 75 years old.

MATERIALS AND METHODS

The HAROW (hormonal therapy, active surveillance, radiation, operation and watchful waiting) study is a prospective, observational study designed to collect clinical data and patient reported outcome of different treatment options for patients newly diagnosed with localized prostate cancer under real conditions. At 6-month intervals general clinical data, PROs (e.g. quality of life, quality of physician-patient interaction) and individual costs are documented. Data from 2,482 patients at 4 time points from T0 (initial diagnosis) to T3 (24 months follow-up) were analyzed.

RESULTS

T-tests and χ(2)-tests revealed no significant differences in terms of shared decision-making and information to different treatment options between patients aged over 75 years old and the rest of the sample. Regarding information on self-help groups, rehabilitation options and a second medical opinion, there were significant differences between prostate cancer patient age groups: patients aged over 75 years old received less information on these aspects at all points in time.

CONCLUSION

Patients at all ages feel activated by urologists and are informed about different treatment options. However, there is room for improvement in terms of informing especially elderly prostate cancer patients about rehabilitation, second medical opinions and self-help groups. Special information tools and decision aids for prostate cancer patients aged over 75 years old should be developed and implemented to meet the specific information needs.

Effects of vitamin A supplementation and weaning age on serum and liver retinol concentrations, carcass traits, and lipid composition in market beef cattle

Angus crossbred steers (n=48) were either early-weaned (EW) at 137 days or weaned at a traditional age (TW) of 199 days to determine effects of weaning age and dietary vitamin A on serum and liver retinol, carcass traits, and lipid composition. Steers from both weaning ages were allotted to receive either 42,180IU vitamin A/day (HA) or no supplemental vitamin A (NA). Early-weaned and TW steers consumed vitamin A treatments for 235 and 175 days, respectively. Serum and liver retinol of HA steers were dramatically higher (P<0.01) than those of NA steers at the end of finishing. Steers were harvested in two groups 35 days apart at an average ultrasound 12th rib fat thickness of 1.0cm. Live and HCW were similar (P>0.10) between NA and HA steers, but HA steers had numerically greater (P⩾0.10) fat thickness (1.05 vs. 0.87cm). Marbling score and %IMF fat were numerically (P>0.10) higher for EWNA than EWHA steers. Ratio of marbling score/12th rib fat thickness was greater (P=0.08), and ratios of either marbling or %IMF per unit of 12th rib fat thickness, days on finishing diet, unit of HCW, and tenth of yield grade consistently favored steers fed NA, particularly EW steers. Proportions of serum fatty acids changed (P<0.05) during finishing; proportions of individual fatty acids of the longissimus muscle did not change. Restricting vitamin A during finishing has potential to increase carcass marbling and to decrease waste fat, particularly for EW.

Developing core sets for persons with bipolar disorder based on the International Classification of Functioning, Disability and Health

INTRODUCTION

Functioning is increasingly being taken into account when assessing the impact of bipolar disorder (BD) on the individual, as well as the effectiveness of treatments. With the International Classification of Functioning, Disability and Health (ICF), we can now rely on a globally agreed-upon framework and system for classifying the typical spectrum of problems in functioning, given the environmental context in which subjects live. ICF Core Sets are subgroups of ICF items selected to capture those aspects of functioning that are most likely to be affected by specific disorders. Within a given disorder, both Brief and Comprehensive Core Sets can be established to serve specific purposes.

OBJECTIVE

The aim of this paper is to outline the development process of the ICF Core Sets for BD.

METHODS

The final definition of ICF Core Sets for BD will be determined at an ICF Core-Sets Consensus Conference, which will integrate evidence from preliminary studies, namely (a) semi-structured interviews with people with BD in different countries, (b) a Delphi exercise with international experts participating and (c) a cross-sectional study.

CONCLUSION

ICF Core Sets are being designed with the goal of providing useful standards for research, clinical practice and teaching. We believe that these ICF Core Sets for BD will stimulate research leading to improved understanding of functioning, disability and health in BD. Such research, we hope, will lead to interventions and accommodations to improve restoration and maintenance of functioning and minimise disability among people with BD throughout the world.

Evaluation of methodological and biological influences on the collection and composition of exhaled breath condensate

The purpose of this inter-species comparison (calves and pigs) was to identify methodological and biological influences on the collection and composition of exhaled breath condensate (EBC). A total of 352 EBC samples were collected, whilst variables of ventilation were registered in parallel. Partial pressure of carbon dioxide (pCO2) and pH were analysed in non-degassed EBC samples. The concentration of total protein in EBC was measured colorimetrically. In both species, lung function was evaluated before and after EBC collection. Statistical analyses were performed to study the effect of EBC collection on lung function and to identify the influence of ventilatory variables on the collection and composition of EBC. Collection of EBC did not affect lung function. Despite the volume of EBC collected per unit time being primarily dependent on ventilation per unit time, species-specific conditions during the EBC collection process resulted in different dependences of EBC collection from other variables of ventilation (i.e. maximal airflow during expiration or expired tidal volume kg-1 body weight). The concentration of protein ml(-1) EBC increased with the expired volume per min and with peak expiratory flow. Although the pCO2 in fresh EBC was significantly negatively dependent on the duration of collection, comparable pHs (5.6 - 6.2) were measured in EBC of both calves and pigs. The obtained data may help one standardize EBC collection in different species.

The Occurrence of PVYO, PVYN, and PVYN:O Strains of Potato virus Y in Certified Potato Seed Lot Trials in Washington and Oregon

Totals of 960 and 286 certified potato seed lots from locations across North America were planted in trials in Washington and Oregon, respectively, in 2001 to 2003 and tested for strains of Potato virus Y (PVY). The incidence of PVY^O-infected lots averaged 16.4 and 25.9% in the Washington and Oregon trials, respectively. There was a general trend of increasing incidence of the PVY^O, PVY^N:O, and PVY^N strains during this period, as evidenced by more infected cultivars, sites of seed origin, and number of seed growers providing infected seed lots. In particular, there was a dramatic increase in seed lots with the PVY^N:O strain from 2002 to 2003. PVY^N:O, in contrast to PVY^O, which only causes yield reduction, also causes internal and external damage to tubers, making them unmarketable. In 2003, PVY^N:O occurred in seed lots originating in eight states and three Canadian provinces. The increased incidence of PVY^N:O was likely due to the difficulty in differentiating this strain from PVY^O. The prevalence of PVY in potato seed lots documented herein poses a threat to potato production in the United States and suggests that current measures to reduce the incidence of this virus are inadequate.

Evaluation of lung function in pigs either experimentally or naturally infected with Chlamydiaceae

This study evaluated the influence of chlamydial infections on lung function in conventionally raised pigs. Eight pigs aged 39-44 days were included in an aerogeneous challenge model (4 were exposed to Chlamydia suis; 4 served as controls). Nineteen pigs aged 5-27 weeks without clinical symptoms (but partly PCR-positive for chlamydial species) were examined over 6 months. For lung function testing, impulse oscillometry was used. In total, all 27 pigs underwent 465 lung function tests. Variables of ventilation (respiratory rate, tidal volume, minute volume), respiratory impedance (expressed as resistance and reactance within the frequency range 3-15 Hz), and model derived resistance of proximal and distal airways were measured. Experimental exposure to C. suis significantly affected lung function. Early distal airway obstruction (3-5 days after infection) was followed by an obstruction of proximal airways (7 days after infection). The breathing pattern was significantly changed (decreased tidal volume; increased respiratory rate). In symptom-free pigs having a naturally acquired presence of different chlamydial species in the respiratory system, no deterioration in lung function could be determined up to the age of 6 months. In conclusion, the consequences of respiratory chlamydial infections appear to vary from clinical inapparence to severe respiratory distress.

Improved gene selection for classification of microarrays

In this paper we derive a method for evaluating and improving techniques for selecting informative genes from microarray data. Genes of interest are typically selected by ranking genes according to a test-statistic and then choosing the top k genes. A problem with this approach is that many of these genes are highly correlated. For classification purposes it would be ideal to have distinct but still highly informative genes. We propose three different pre-filter methods--two based on clustering and one based on correlation--to retrieve groups of similar genes. For these groups we apply a test-statistic to finally select genes of interest. We show that this filtered set of genes can be used to significantly improve existing classifiers.

A cellular oscillator model for periodic pattern formation

In this paper, we present a model for pattern formation in developing organisms that is based on cellular oscillators (CO). An oscillatory process within cells serves as a developmental clock whose period is tightly regulated by cell autonomous or non-autonomous mechanisms. A spatial pattern is generated as a result of an initial temporal ordering of the cell oscillators freezing into spatial order as the clocks slow down and stop at different times or phases in their cycles. We apply a CO model to vertebrate somitogenesis and show that we can reproduce the dynamics of periodic gene expression patterns observed in the pre-somitic mesoderm. We also show how varying somite lengths can be generated with the CO model. We then discuss the model in view of experimental evidence and its relevance to other instances of biological pattern formation, showing its versatility as a pattern generator.

Sustained suppression of neointimal proliferation by sirolimus-eluting stents: one-year angiographic and intravascular ultrasound follow-up

BACKGROUND

We have previously reported a virtual absence of neointimal hyperplasia 4 months after implantation of sirolimus-eluting stents. The aim of the present investigation was to determine whether these results are sustained over a period of 1 year.

METHODS AND RESULTS

Forty-five patients with de novo coronary disease were successfully treated with the implantation of a single sirolimus-eluting Bx VELOCITY stent in São Paulo, Brazil (n=30, 15 fast release [group I, GI] and 15 slow release [GII]) and Rotterdam, The Netherlands (15 slow release, GIII). Angiographic and volumetric intravascular ultrasound (IVUS) follow-up was obtained at 4 and 12 months (GI and GII) and 6 months (GIII). In-stent minimal lumen diameter and percent diameter stenosis remained essentially unchanged in all groups (at 12 months, GI and GII; at 6 months, GIII). Follow-up in-lesion minimal lumen diameter was 2.28 mm (GIII), 2.32 mm (GI), and 2.48 mm (GII). No patient approached the >/=50% diameter stenosis at 1 year by angiography or IVUS assessment, and no edge restenosis was observed. Neointimal hyperplasia, as detected by IVUS, was virtually absent at 6 months (2+/-5% obstruction volume, GIII) and at 12 months (GI=2+/-5% and GII=2+/-3%).

CONCLUSIONS

This study demonstrates a sustained suppression of neointimal proliferation by sirolimus-eluting Bx VELOCITY stents 1 year after implantation.

Expression, purification and secondary structure analysis of Saccharomyces cerevisiae vacuolar membrane H+-ATPase subunit F (Vma7p)

The vacuolar H+-ATPase is an acid pump found in virtually all eukaryotic cells. It shares a common macromolecular organization with the F1F0-ATPase, and some V-ATPase subunits are structural and functional homologues of F-ATPase components. However, the vacuolar complex contains several subunits which do not resemble F-ATPase subunits at the sequence level, and which currently have no specific function assigned. One example is subunit F, the Vma7p polypeptide of Saccharomyces cerevisiae. A recombinant form of Vma7p was expressed in Escherichia coli and purified to homogeneity. Mass spectroscopy confirmed a mass of 13460 Da for Vma7p, and dynamic light scattering showed that the polypeptide was globular and monodisperse even at high concentrations. Analysis of secondary structure by circular dichroism and FTIR showed that Vma7p comprises 30% alpha-helix and 32-42% beta-sheet. The protein fold recognition programme 'Threader 2' produced highly significant matches between Vma7p and five alpha-beta sandwich folds. Relative proportions of secondary structure elements within these folds were broadly consistent with the spectroscopic data. Although Vma7p does not share sequence similarity with the F-ATPase epsilon subunit, the analysis suggests that the polypeptides not only have similar masses and assemble into homologous core complexes, but also share similar secondary structures. It is possible that the two polypeptides are homologous and perform similar functions within their respective ATPases. The production of high yields of homogeneous, folded, monodisperse protein will facilitate high resolution crystallography and NMR spectroscopy studies.

Lack of neointimal proliferation after implantation of sirolimus-coated stents in human coronary arteries: a quantitative coronary angiography and three-dimensional intravascular ultrasound study

BACKGROUND

Restenosis remains an important limitation of interventional cardiology. Therefore, we aimed to determine the safety and efficacy of sirolimus (a cell-cycle inhibitor)-coated BX Velocity stents.

METHODS AND RESULTS

Thirty patients with angina pectoris were electively treated with 2 different formulations of sirolimus-coated stents (slow release [SR], n=15, and fast release [FR], n=15). All stents were successfully delivered, and patients were discharged without clinical complications. Independent core laboratories analyzed angiographic and 3D volumetric intravascular ultrasound data (immediately after procedure and at 4-month follow-up). Eight-month clinical follow-up was obtained for all patients. There was minimal neointimal hyperplasia in both groups (11.0+/-3.0% in the SR group and 10.4+/-3.0% in the FR group, P:=NS) by ultrasound and quantitative coronary angiography (in-stent late loss, 0.09+/-0.3 mm [SR] and -0.02+/-0.3 mm [FR]; in-lesion late loss, 0.16+/-0.3 mm [SR] and -0.1+/-0.3 mm [FR]). No in-stent or edge restenosis (diameter stenosis >or=50%) was observed. No major clinical events (stent thrombosis, repeat revascularization, myocardial infarction, or death) had occurred by 8 months.

CONCLUSIONS

The implantation of sirolimus-coated BX Velocity stents is feasible and safe and elicits minimal neointimal proliferation. Additional placebo-controlled trials are required to confirm these promising results.

Association of resident coverage with cost, length of stay, and profitability at a community hospital

OBJECTIVE

The effect of care by medical residents on hospital length of stay (LOS), indirect costs, and reimbursement was last examined across a range of illnesses in 1981; the issue has never been examined at a community hospital. We studied resource utilization and reimbursement at a community hospital in relation to the involvement of medical residents.

DESIGN

This nonrandomized observational study compared patients discharged from a general medicine teaching unit with those discharged from nonteaching general medical/surgical units.

SETTING

A 620-bed community teaching hospital with a general medicine teaching unit (resident care) and several general medicine nonteaching units (no resident care).

PATIENTS

All medical discharges between July 1998 and February 1999, excluding those from designated subspecialty and critical care units.

MEASUREMENTS AND MAIN RESULTS

Endpoints included mean LOS in excess of expected LOS, mean cost in excess of expected mean payments, and mean profitability (payments minus total costs). Observed values were obtained from the hospital's database and expected values from a proprietary risk-cost adjustment program. No significant difference in LOS between 917 teaching-unit patients and 697 nonteaching patients was demonstrated. Costs averaged $3,178 (95% confidence interval (CI) +/- $489) less than expected among teaching-unit patients and $4,153 (95% CI +/- $422) less than expected among nonteaching-unit patients. Payments were significantly higher per patient on the teaching unit than on the nonteaching units, and as a result mean, profitability was higher: $848 (95% CI +/- $307) per hospitalization for teaching-unit patients and $451 (95% CI +/- $327) for patients on the nonteaching units. Teaching-unit patients of attendings who rarely admitted to the teaching unit (nonteaching attendings) generated an average profit of $1,299 (95% CI +/- $613), while nonteaching patients of nonteaching attendings generated an average profit of $208 (95% CI +/- $437).

CONCLUSIONS

Resident care at our community teaching hospital was associated with significantly higher costs but also with higher payments and greater profitability.

Available pathways database (APD): an essential resource for combinatorial biology

A relational database, the Available Pathways Database (APD), has been constructed of microbial natural products, their producing strains, and their biosynthetic pathways. The database allows the ready selection of donor strains for combinatorial biology experiments. It provides the same type of resource for combinatorial biology as the Available Chemicals Directory (ACD) does for combinatorial chemical library generation. Its cataloging ability can also provide insight into novel aspects of biosynthetic routes. In particular, no 10-unit Type I polyketides were found in the compilation of this edition of the APD (Version I).

Gasless versus conventional laparoscopy

The objective of our study was to evaluate the technical advantages of using the Laparolift device and examine the clinical benefits of gynecologic laparoscopy without pneumoperitoneum. A randomized single-blinded clinical trial was performed employing a sample of 30 consecutive patients undergoing laparoscopic gynecologic surgery with a primary outcome measure of visualization. Visualization was found to be inferior in gasless patients. The conclusion was that conventional laparoscopy employing pneumoperitoneum provides surgical exposure superior to that offered by the Laparolift device.

A new primate from the Middle Eocene of Myanmar and the Asian early origin of anthropoids

A new genus and species of anthropoid primate, Bahinia pondaungensis gen. et sp. nov., is described from the Yashe Kyitchaung locality in the Late Middle Eocene Pondaung Formation (Myanmar). It is related to Eosimias, but it is represented by more complete remains, including upper dentition with associated lower jaw fragment. It is interpreted as a new representative of the family Eosimiidae, which corresponds to the sister group of the Amphipithecidae and of all other anthropoids. Eosimiidae are now recorded from three distinct Middle Eocene localities in Asia, giving support to the hypothesis of an Asian origin of anthropoids.

The active site base controls cofactor reactivity in Escherichia coli amine oxidase: x-ray crystallographic studies with mutational variants

Amine oxidases utilize a proton abstraction mechanism following binding of the amine substrate to the C5 position of the cofactor, the quinone form of trihydroxyphenylalanine (TPQ). Previous work [Wilmot, C. M., et al. (1997) Biochemistry 36, 1608-1620] has shown that Asp383 in Escherichia coliamine oxidase (ECAO) is the catalytic base which performs the key step of proton abstraction. This paper explores in more depth this and other roles of Asp383. The crystal structures of three mutational variants are presented together with their catalytic properties, visible spectra, and binding properties for a substrate-like inhibitor, 2-hydrazinopyridine (2-HP), in comparison to those of the wild type enzyme. In wild type ECAO, the TPQ is located in a wedge-shaped pocket which allows more freedom of movement at the substrate binding position (C5) than for TPQ ring carbons C1-C4. A role of Asp383, whose carboxylate is located close to O5, is to stabilize the TPQ in its major conformation in the pocket. Replacement of Asp383 with the isostructural, but chemically distinct, Asn383 does not affect the location or dynamics of the TPQ cofactor significantly, but eliminates catalytic activity and drastically reduces the affinity for 2-HP. Removal of the side chain carboxyl moiety, as in Ala383, additionally allows the TPQ the greater conformational flexibility to coordinate to the copper, which demonstrates that Asp383 helps maintain the active site structure by preventing TPQ from migrating to the copper. Glu383 has a greatly decreased catalytic activity, as well as a decreased affinity for 2-HP relative to that of wild type ECAO. The electron density reveals that the longer side chain of Glu prevents the pivotal motion of the TPQ by hindering its movement within the wedge-shaped active site pocket. The results show that Asp383 performs multiple roles in the catalytic mechanism of ECAO, not only in acting as the active site base at different stages of the catalytic cycle but also in regulating the mobility of the TPQ that is essential to catalysis.

The structure of HIV-1 reverse transcriptase complexed with an RNA pseudoknot inhibitor

Small RNA pseudoknots, selected to bind human immunodeficiency virus type 1 (HIV-1) reverse transcriptase tightly, are potent inhibitors of reverse transcriptase. The co-crystal structure of reverse transcriptase complexed with a 33 nucleotide RNA pseudoknot has been determined by fitting the ligand into a high quality, 4-fold averaged 4.8 A resolution electron density map. The RNA is kinked between stems S1 and S2, thereby optimizing its contacts with subunits of the heterodimer. Its binding site extends along the cleft that lies between the polymerase and RNase H active sites, partially overlaps with that observed for duplex DNA and presumably overlaps some portion of the tRNA site. Stem S2 and loop L1 stabilize the 'closed' conformation of the polymerase through extensive electrostatic interactions with several basic residues in helix I of the p66 thumb and in the p66 fingers domain. Presumably, this RNA ligand inhibits reverse transcriptase by binding to a site that partly overlaps the primer-template binding site.

Structural and mechanistic consequences of polypeptide binding by GroEL

The remarkable ability of the chaperonin GroEL to recognise a diverse range of non-native states of proteins constitutes one of the most fascinating molecular recognition events in protein chemistry. Recent structural studies have revealed a possible model for substrate binding by GroEL and a high-resolution image of the GroEL-GroES folding machinery has provided important new insights into our understanding of the mechanism of action of this chaperonin. Studies with a variety of model substrates reveal that the binding of substrate proteins to GroEL is not just a passive event, but can result in significant changes in the structure and stability of the bound polypeptide. The potential impact of this on the mechanism of chaperonin-assisted folding is not fully understood, but provides exciting scope for further experiment.

Immune response to Escherichia coli O157:H7 in hemolytic uremic syndrome following salmonellosis

Escherichia coli O157:H7, a Shiga-like toxin (SLT)-producing enteric pathogen, has been implicated in most cases of post-diarrheal hemolytic uremic syndrome (D + HUS). Infection with other bacterial pathogens such as Salmonella has also preceded D + HUS episodes, leading to speculation that these organisms may also be etiological. We present two children with unrelated D + HUS following salmonellosis. Both children had negative stool cultures on sorbitol-MacConkey agar soon after the onset of diarrhea. After the diagnosis of HUS, both patients had repeat stool cultures positive for Salmonella alone. Polymerase chain reactions for SLT I and II gene sequences in Salmonella isolates were negative. Enzyme-linked immunosorbent assay for specific humoral response to E. coli O157:H7 lipopolysaccharide in acute and convalescent serum samples revealed evidence of heretofore undetected E. coli O157:H7 infection contemporaneous with each D + HUS episode. These cases demonstrate that isolation of only non-SLT-producing microbes from children with D + HUS should raise suspicion of concurrent undetected infection with SLT-producing organisms. Assaying specific immune response to E. coli O157:H7 can be an important epidemiological adjunct. Bacterial infection with non-SLT-producing Salmonella may represent concomitant enteric pathology rather than D + HUS-instigating infection.

School-based AIDS education for adolescents

PURPOSE

To describe a program which utilizes medical students and persons with AIDS (PWAs) to provide for adolescents school-based education about acquired immunodeficiency syndrome (AIDS).

METHODS

Two 1.5 hour classroom sessions were conducted by medical students and persons with AIDS for seventh and eighth grade students (n = 1,161 students) at two urban middle schools. In addition, a two hour informational session was provided for parents. A 49 question student health survey was used to evaluate adolescents' HIV knowledge, tolerance of persons with AIDS, and intentions to engage in human immunodeficiency virus (HIV) safe behaviors.

RESULTS

Significant (p < 0.01) increases in HIV knowledge and tolerance of persons with AIDS were observed, which persisted for three months. A significant (p < 0.01) improvement in intention to engage in HIV-safe behaviors was observed but did not persist for three months.

CONCLUSIONS

Medical students and persons with AIDS can provide school-based AIDS education to early adolescents.

Peroxide accumulation in detergents

It is known that polyether detergents have a propensity for peroxide accumulation but the rate of this accumulation and the conditions under which it occurs are not well-appreciated. We here describe the use of the FOX (ferrous oxidation in Xylenol orange) assay as a screen for detergent peroxide accumulation. We also show that a chain-breaking antioxidant, but not a metal-chelating agent block peroxide accumulation in detergent stored in the light at room temperature.

Endotherm Energetics - From a Scalable Individual-Based Model to Ecological Applications

We outline a computer model of heat and mass transfer through flesh, fat and porous fur for endotherms of any dimensions. We then validate it with a series of laboratory studies. Finally, we explore applications of the model to Bergmann's rule, predicting the mouse-to-elephant curve, climate-disease-toxicant interactions, animal 'design' via genetic engineering and energetic constraints on community structure. As a first test of the model we present calculations and metabolic chamber measurements for mammals ranging in size from mice to Holstein calves. We then compare simultaneous measurements on deer mice, Peromyscus maniculatus, of oxygen consumption, doubly labelled water turnover and food consumption with calculations of metabolic rate using body temperature radio-telemetry as input to the endotherm model. The endotherm model derived in the Appendix requires data on allometry (body dimensions, surface area), fur properties, core temperature, air and radiant temperatures and wind speed. The model is useful for calculating energetic expenditure in different microclimates without the need for extensive physiological measurements in the laboratory. Model predictions of metabolic rate at 12-degrees-C and at 22-degrees-C were well correlated with each of the three empirical estimates. The model shows that the posture an animal assumes can influence measurements of metabolic rate. Model calculations of metabolic rate using postures ranging from a curled-up ball-like geometry to a sprawled-out, cylinder or ellipsoid geometry bracket all three sets of simultaneous empirical data taken on the same animals. Applications of the model show that it can be applied in a wide variety of circumstances to gain insight into physiological and ecological problems.

Crystallographic refinement and structure analysis of the complex of wheat germ agglutinin with a bivalent sialoglycopeptide from glycophorin A

Wheat germ agglutinin (WGA) elicits a number of biological effects in erythrocytes as a result of specific binding to the transmembrane protein glycophorin A. The structure of co-crystals of WGA (isolectin 1: WGA1) with a bivalent sialoglycopeptide fragment of glycophorin A (T5), determined at 2.0 A resolution, has been further refined and analyzed with respect to ligand-induced changes in the tertiary structure, mobility, solvation, saccharide conformation and protein/saccharide interactions at three independent N-acetyl-D-neuraminic (NeuNAc) binding sites. The final model, which includes the two independent WGA1 monomers (composed of domains A, B, C and D), two positions for bound T5 sialo-tetrasaccharide (NeuNAc-alpha 2,3-Gal-beta 1,3-(alpha 2,6-NeuNAc)GalNAc) and 386 water molecules, refined to a crystallographic R-factor of 17.1% (Fo > 1.0 sigma) and an average temperature factor of 31.99 A2. Comparisons between the tertiary structures of the liganded and unliganded WGA1 dimers indicate that the largest deviations from 2-fold symmetry are localized in domains engaged in sugar binding (B1 and C2) and at the C-terminal domain of monomer II (D2), forming a strong lattice contact. Interactions of the tetrasaccharide with amino acid ligands in the three binding sites and with water were carefully analyzed and compared. Bound conformations of terminal NeuNAc match to within a root-mean-square delta r of 0.3 A. The specificity-determining N-acetyl group superimposes best in comparison with other substituents of the sugar ring. Of the five domain binding sites that are not occupied in this dimeric crosslinked complex, only one is accessible to the NeuNAc monosaccharide as determined from a difference Fourier map at 3.0 A resolution.

Neuropsychiatric rehabilitation for persistent mental illness

The benefits of new knowledge on the psychobiology and neuropsychology of serious mental illnesses have been slow to impact on psychiatric rehabilitation technology. A literature review reveals that, at least in the case of schizophrenia, enough is known about neurobiological deficits and their impact on neurocognitive functioning to justify a more informed approach to psychiatric rehabilitation. Essential elements for a program of research are presented and preliminary data are reported examining the prevalence of executive deficits, correlations between neuropsychological deficits and social adjustment, and the nature of socially stigmatizing neuromotor deficits and their reliable assessment. In addition, early experience with the remediation of executive deficits is described and suggestions are made for future developments in this area. The authors conclude that barriers to the integration of knowledge from biological psychiatry and psychiatric rehabilitation have been largely related to academic "cultural" isolation, and that active cross fertilization of ideas is clearly justified by the present state of knowledge.

Crystallization and preliminary X-ray diffraction studies of dialkylglycine decarboxylase, a decarboxylating transaminase

The pyridoxal phosphate-dependent enzyme dialkylglycine decarboxylase (E.C. 4.1.1.64) has been crystallized by vapor diffusion from a 15% polyethyleneglycol solution with sodium pyruvate as coprecipitant. The space group of the crystals is either P6(2)22 or the enantiomorph, P6(4)22, with one subunit of 46,500 Da per asymmetric unit. The unit cell has dimensions a = b = 152.7 A, c = 86.6 A, alpha = beta = 90 degrees, gamma = 120 degrees, and a solvent content of approximately 61%. diffraction extends to 2.3 A resolution.

The measurement of subjective experience in schizophrenia: the Subjective Deficit Syndrome Scale

The systematic assessment of subjective experience independently from its impact on schizophrenic's behavior is neglected in most structured interviews and symptoms rating scales. However, subjective complaints may predict outcome functioning, medication compliance, and future psychotic episodes and better reflects patients' well-being than does behavioral assessment. We demonstrate the reliability of the Subjective Deficit Syndrome Scale and the considerable prevalence of subjective complaints in 166 acute and chronic inpatients and outpatients. Complaints were correlated with global measures of psychopathology in acute but not chronic patients. They were not correlated with negative symptoms or neurological side effects. Some overlap was observed with measures of depression, although most patients denied depressed mood. We conclude that subjective deficits are prevalent in schizophrenia, that they can be reliably assessed, and that they constitute an independent, clinically important dimension of the disease.

Self-reported neuroendocrine effects of antipsychotics in women: a pilot study

Although neuroendocrine adverse effects (NAEs) of antipsychotic agents in women have been widely reported, it has been generally assumed that either (1) tolerance to these effects develops with chronic use, (2) patients adjust to the effects, or (3) a trial of dopamine-agonist treatment is effective. We have begun to examine the prevalence of chronic adverse effects and their effect on compliance using a pilot study of self-reported NAEs, antipsychotic drugs, and compliance patterns in a naturalistic setting. Twenty chronic psychiatric outpatients who had been continuously prescribed antipsychotic agents for a minimum of six months were interviewed. The major finding is the greater antipsychotic dose exposure among those with self-reported NAEs compared with those without NAEs (781 +/- 606 chlorpromazine-equivalent mg/d vs. 125 +/- 117, p less than 0.001). High-potency agents were prescribed for all of the patients reporting amenorrhea and/or galactorrhea, although the relationship between potency group (high vs. low) and total neuroendocrine effects was not significant. Self-reported compliance was not significantly related to neuroendocrine adverse effects. However, a trend toward the association of self-reported galactorrhea and noncompliance (p = 0.08) is noted. The implications of these findings and a suggested approach for their replication in a more powerful statistical analysis is discussed.

Neurological impairment in violent schizophrenic inpatients

This study relates violent behavior of schizophrenic inpatients to demographic, historical, EEG, neurological, and neuropsychological variables. Patients were classified into high (N = 28), low (N = 27), or no (N = 34) violence groups. There were no significant differences among the groups on demographic or historical variables, except for prevalence of violent crime, which was higher in both violent groups than in nonviolent patients. Neurological and neuropsychological abnormalities differentiated the groups, with the high violence group evidencing more abnormalities than the other two groups in the area of integrative sensory and motor functions. The authors suggest that violence as well as neurological and neuropsychological deficits may characterize a more severe form of schizophrenia.

Inpatient violence: trait and state

This study compared patients who showed persistent violence, transient violence and no violence. The presence of neurological abnormalities was found to be the factor that differentiated most clearly among the three groups. The persistently violent patients, in addition to showing significantly more neurological abnormalities, also evidenced a more disturbed family background. Both violent groups had a higher incidence of violent crime prior to hospitalization than the nonviolent controls. A logistic regression model simultaneously relating the effects of six factors on violent behavior was developed and used to predict violent group membership.