An olivine cumulate outcrop on the floor of Jezero crater, Mars.

The geological units on the floor of Jezero crater, Mars, are part of a wider regional stratigraphy of olivine-rich rocks, which extends well beyond the crater. We investigated the petrology of olivine and carbonate-bearing rocks of the Séítah formation in the floor of Jezero. Using multispectral images and x-ray fluorescence data, acquired by the Perseverance rover, we performed a petrographic analysis of the Bastide and Brac outcrops within this unit. We found that these outcrops are composed of igneous rock, moderately altered by aqueous fluid. The igneous rocks are mainly made of coarse-grained olivine, similar to some martian meteorites. We interpret them as an olivine cumulate, formed by settling and enrichment of olivine through multistage cooling of a thick magma body.

Maximizing Fibroblast Adhesion on Protein-Coated Surfaces Using Microfluidic Cell Printing.

translation of in vitro cell based assays to in vivo cellular response is imprecise at best. The advent of three-dimensional cell cultures in addition to bioreactor type microfluidics has improved the situation. However, these technical advances cannot be easily combined due to practical limitations. Development of a vertical microfluidic cell printer overcomes this obstacle, providing the ability to more closely recapitulate complex cellular environments and responses. As a proof of concept, we investigated the adhesion of fibroblasts under flow on protein-coated surfaces using a novel vertical microfluidic print head to isolate and manipulate both mechanical and biological factors as a model of fibroblast behavior during the foreign body response following implant insertion. A low flow rate with larger microfluidic channels onto a serum-coated surface has been determined to allow the highest density of viable fibroblasts to attach to the surface. While these insights into fibroblast surface attachment may lead to better material designs, the methods developed herein will certainly be useful as a biomaterials testing platform.

A critical comparison of protein microarray fabrication technologies.

Of the diverse analytical tools used in proteomics, protein microarrays possess the greatest potential for providing fundamental information on protein, ligand, analyte, receptor, and antibody affinity-based interactions, binding partners and high-throughput analysis. Microarrays have been used to develop tools for drug screening, disease diagnosis, biochemical pathway mapping, protein-protein interaction analysis, vaccine development, enzyme-substrate profiling, and immuno-profiling. While the promise of the technology is intriguing, it is yet to be realized. Many challenges remain to be addressed to allow these methods to meet technical and research expectations, provide reliable assay answers, and to reliably diversify their capabilities. Critical issues include: (1) inconsistent printed microspot morphologies and uniformities, (2) low signal-to-noise ratios due to factors such as complex surface capture protocols, contamination, and static or no-flow mass transport conditions, (3) inconsistent quantification of captured signal due to spot uniformity issues, (4) non-optimal protocol conditions such as pH, temperature, drying that promote variability in assay kinetics, and lastly (5) poor protein (e.g., antibody) printing, storage, or shelf-life compatibility with common microarray assay fabrication methods, directly related to microarray protocols. Conventional printing approaches, including contact (e.g., quill and solid pin), non-contact (e.g., piezo and inkjet), microfluidics-based, microstamping, lithography, and cell-free protein expression microarrays, have all been used with varying degrees of success with figures of merit often defined arbitrarily without comparisons to standards, or analytical or fiduciary controls. Many microarray performance reports use bench top analyte preparations lacking real-world relevance, akin to "fishing in a barrel", for proof of concept and determinations of figures of merit. This review critiques current protein-based microarray preparation techniques commonly used for analytical and function-based proteomics and their effects on array-based assay performance.

Whole gut transit scintigraphy in the clinical evaluation of patients with upper and lower gastrointestinal symptoms.

OBJECTIVE: In a single noninvasive, quantitative test, whole gut transit scintigraphy (WGTS) measures gastric emptying (GE), small bowel transit (SBT), and colonic transit (CT). The aim of this study was to investigate the clinical utility of WGTS in patients with functional gastrointestinal (GI) symptoms. METHODS: A total of 108 patients with either dyspeptic upper GI symptoms (n = 35) or constipation (n = 73) underwent WGTS. Patients consumed a meal of 99 m-Tc egg sandwich with 111-In DTPA in water. They were imaged every 30 min for 6 h to measure GE and SBT, and at 24, 48, and 72 h to measure CT. RESULTS: Of 108 studies, 104 were analyzable. In patients with upper GI symptoms, 14/35 (40%) had delayed GE of solids, 4/35 (11%) delayed SBT, and 11/35 (31%) delayed CT. Of those with constipation, 13/69 (19%) had delayed GE, 5/69 (7%) delayed SBT, and 43/69 (65%) delayed CT. WGTS changed the initial clinical diagnosis in 47/104 (45%) and altered patient management in 70/104 (67%) of the patients. CONCLUSIONS: Transit abnormalities of the upper GI tract and colon are common in patients with functional GI symptoms. Patients with upper GI symptoms frequently have delayed GE, whereas those with constipation tend to have predominantly delayed CT. In many patients with functional GI symptoms, there was evidence of a diffuse GI motility disorder. Whole gut transit scintigraphy is a simple, clinically useful test, as it frequently leads to a change in diagnosis and, therefore, patient management.

Acute administration of SCH23390 increases D(1) receptors on nonpyramidal neurons in rat mPFC.

Atypical antipsychotic drugs (APDs) such as clozapine and olanzapine antagonize both D(1) and D(2) receptors; however, little is known regarding their pharmacologic effect on specific neuronal elements within the local circuitry of corticolimbic regions, such as medial prefrontal cortex (mPFC). To characterize the effect of short-term antagonism of the D(1) receptor a high-resolution autoradiographic technique was used to assess the density (B(max)) and affinity (K(d)) of this receptor on pyramidal cells (i.e., large neurons (LNs, >/=100 microm(2))), nonpyramidal cells (i.e., small neurons (SNs, <100 microm(2))) and in the surrounding neuropil (NPL) of layer VI in rat mPFC. Either normal saline or the selective D(1) antagonist SCH23390 (1.0 mg/kg/day) were administered for 48 h via Alzet osmotic pumps. Frozen sections were incubated in [(3)H]SCH23390 (1-8 nM) in the presence or absence of the competitive inhibitor SKF38393 (10 microM). A microscopic adaptation to Scatchard analysis revealed a significant increase (82%) in B(max) for neuronal cell bodies (P < 0.05), but not for neuropil of drug-treated animals. Further analysis indicated that the increase in B(max) was present on SNs (94%, P < 0.05), but not LNs in SCH23390-treated rats. In contrast, K(d) values for LNs, SNs, and NPL were not significantly altered by drug treatment. Since the vast majority of SNs are nonpyramidal in nature, short-term administration of a selective D(1) antagonist seems to be associated with a preferential upregulation of this receptor on interneurons. Overall, these results are consistent with the hypothesis that the mechanism of action of atypical antipsychotic medications involves changes in D(1) receptor activity associated with local circuit neurons in rat mPFC.

Effect of video self-observation on development of insight in psychotic disorders.

Many patients with psychotic disorders lack awareness of being ill. This often presents a serious impediment to treatment compliance. We hypothesized that exposing partially remitted patients to videotapes of themselves, made while they were acutely psychotic, might increase their insight into the nature of their illness. Eighteen acutely psychotic inpatients were assigned randomly to a control or experimental group and interviewed on videotape 24 to 48 hours after admission, using scales that measure insight (Insight and Treatment Attitudes Questionnaire [ITAQ]) and psychopathology (Brief Psychiatric Rating Scale [BPRS]). One to six weeks later, when judged to be significantly improved, subjects were shown either a videotape of their initial interview (experimental group) or a placebo videotape (control group) and then reinterviewed 24 to 48 hours later on videotape, using the BPRS and ITAQ scales. Evaluation of initial and final ITAQ and BPRS scores revealed significantly greater improvement in insight scores and in delusionality in the experimental group. However, no significant difference in overall psychopathology was seen for the two groups. These results suggest that exposure of hospitalized patients to videotapes of their own psychotic behavior may be a cost-effective therapeutic tool for developing personal insight into psychotic illness.

High-resolution scatchard analysis shows D1 receptor binding on pyramidal and nonpyramidal neurons.

In order to better understand the mechanism of action of atypical antipsychotic drugs (APDs), it is important to clarify how the dopamine system is integrated within local corticolimbic circuits. Toward this end, a high-resolution (HR) Scatchard technique has been used to measure the relative density (Bmax) and affinity (Kd) of D1 receptors on large neurons (> 100 microm2), on small neurons (< 100 microm2), and in neuropil (NPL) of rat medial prefrontal cortex (mPFC) and to determine the laminar distribution of these receptors for each neuronal compartment. Using [3H] SCH23390 as a ligand, all Kd and Bmax values were found to be similar indicating that D1 receptor activity is not preferentially localized to either large or small neuronal subtypes in mPFC. The density of D1 receptor binding in all three compartments was found to be almost twice as great in layers V and VI, as compared to superficial layers II and III. These results suggest that the blockade of D1 receptors associated with some atypical APDs may involve both pyramidal and nonpyramidal neurons in the PFC.

Legibility and completeness of physicians' handwritten medication orders.

OBJECTIVE: To assess handwritten medication orders for legibility and completeness, legibility of physician signatures, and presence of date and time the orders were written. DESIGN: Descriptive. SETTING: Three patient care units in one hospital in Texas. SAMPLE: One hundred seventy-six medication orders and 55 signatures by 36 different physicians for 39 patients. METHODS: Six experienced nurses evaluated medication orders and signatures for legibility using a rating scale developed for the study. Completeness of medication orders and presence of date and time were determined. RESULTS: Twenty percent [corrected] of the medication orders and 78% of the signatures were illegible or legible with effort. Twenty-four percent of the medication orders were incomplete. Date was omitted on 18% of the medication orders, and time was missing on 58%. CONCLUSION: Difficult-to-read and incomplete medication orders continue to be an important system problem that can increase risk for medication errors and patient harm. Good penmanship and complete orders are unrealistic goals without system support.

Implant-supported overdentures: the ZAAG attachment system.

It has been amply demonstrated during the last decade that there are significant advantages to implant-supported overdentures beyond conventional complete dentures. Several attachment systems exist for connecting the overdenture to the implants, and practically all of them present notable benefits to the patients. This article discusses the use of the Zest Anchor Advanced Generation (ZAAG). This system, an outgrowth from the original Zest attachment, uses both individual implant attachments and bar attachments, and is compatible with all major implant systems. In addition to the retention, stability, and resiliency the ZAAG implant attachment system provides, it has the advantage of placing the resistance force of the attachment close to the implant body.

Late stage soft tissue modification for anatomically correct implant-supported restorations.

For the past decade, the dental profession has developed techniques for producing functionally equivalent implant supported restorations to replace complete dentures. Little thought was given to the development of proper emergence profiles to develop anatomic restorations that were contoured like natural teeth. This article presents a simple method of modifying soft tissues coronal to the implant head that will allow the development of a restoration with correct emergence profile and anatomic contour.

Developing soft tissue contours for implant-supported restorations: a simplified method for enhanced aesthetics.

The success of a full coverage crown restoration, whether placed on a natural abutment or a dental implant, requires healthy and correctly contoured soft tissue "framing" for the restoration. Any compromise in soft tissue configuration may result in an aesthetic and functional failure of the final restoration. Traditionally, soft tissue grafts and other augmentation materials have been utilized to develop natural contours and appearance. The learning objective of this article is to present a simplified technique--the use of wide diameter prosthodontic components--for establishing the correct soft tissue profile. This technique enables the clinician to develop an anatomically correct implant-supported restoration with an aesthetic final result.

Restorative-based treatment planning: determining adequate support for implant-retained fixed restorations.

Brånemark provided the dental profession with guidelines for treatment planning the rehabilitation of edentulous patients with endosseous dental implants in the early 1980s. As oral implantology expanded to include the restoration of partially edentulous patients, treatment planning became increasingly more difficult. With the treatment of various areas of the mouth with combinations of implants and natural teeth, the question of how many implants would be necessary to support a given restorative situation took on added significance. A set of guidelines is presented for treatment planning partially edentulous restorations to determine the minimum number of implants recommended.

The ERA implant-supported overdenture.

Extracoronal Resilient Attachment (ERA) implant-supported overdentures, Class I, Division 1 or Division 3 prostheses, provide an exceptionally stable and retentive prosthetic design for edentulous patients with osseointegrated implants. The ERA System uses either an individual female implant abutment or plastic female patterns that can be incorporated into a bar. The male portion of the attachment is a nylon piece of varying retentive quality. The attachment is resilient, stable, and can be easily serviced.

Slant-lock implant-supported overdenture.

Slant-Lock overdentures, Class I: Division 3 prostheses, provide a stable and retentive prosthetic design for edentulous patients with osseointegrated implants. In patients who have moderate to severe atrophy of the edentulous ridge, the Slant-Lock overdenture provides additional support for the para-oral structures. The prostheses increase the ease of oral hygiene for the edentulous patient, can be constructed using conventional prosthodontic techniques, and are reasonably economical.

A prosthodontic-based implant patient classification system.

Success in dental implant-supported prostheses has traditionally been measured in terms of successful osseointegration of implant fixtures. Clearly, this is not the true measure of success in terms of patient expectations. Patients expect prostheses with which they can function, without embarrassment or insecurity. Therefore, patient evaluation and treatment planning must be concerned with final prosthetic results and how patients will look and function. This article introduces a simple classification system that will help eliminate confusion in treatment-planning with implant patients and will also allow dentists to better advise patients about the goals of treatment. The classification system is based primarily on the prosthetic design that patients will receive and offers a means of quantitating the complexity and, therefore, the predictability of treatment.