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Evaluation of a prototype DNA probe test for the noncultural diagnosis of gonorrhea.

A prototype, nonisotopic, chemiluminescent DNA probe test called the Gen-Probe PACE (Probe Assay-Chemiluminescence Enhanced) system for Neisseria gonorrhoeae (Gen-Probe, San Diego, Calif.) was compared with conventional Martin-Lewis culture medium in JEMBEC plates for the laboratory diagnosis of gonorrhea. This 2-h noncultural assay is based upon the use of an acridinium ester-labeled DNA probe. The rRNA-directed DNA probe hybridizes with the target rRNA, and the hybridized probe is separated from the unhybridized probe through the use of magnetic microparticles. The esterified acridinium is hydrolyzed from the hybridized probe by the addition of an alkaline hydrogen peroxide solution, resulting in the production of visible light which is measured in a luminometer. The amount of light generated is directly proportional to the amount of gonococcal target rRNA present in the sample. A total of 407 clinical specimens (203 urethral and 204 endocervical) were collected from high-risk walk-in patients attending a sexually transmitted disease clinic. Separate patient specimens were collected for culture on Martin-Lewis medium in JEMBEC plates and for DNA probe assay. Statistical analysis of the overall comparative results showed that the DNA probe assay had a sensitivity, specificity, and positive and negative predictive values of 93, 99, 97, and 99%, respectively, in a patient population with a gonococcal disease prevalence of 21%. The results of this comparative study showed that the prototype chemiluminescent DNA probe assay is a rapid and reliable noncultural alternative for the laboratory diagnosis of gonorrhea.

DNA Probes

Heterogeneity of capsid proteins of echovirus type 25 wild-type strain and prototype strain, studied by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting were used to compare the capsid proteins of 19 antigenic variants of echovirus type 25 wild-type strains isolated in France between 1976 and 1987 with those of the prototype JV-4 reference strain isolated in 1957. Immunoblots were developed by using polyclonal sera from rabbits and mice immunized with the reference strain. Immunoblotting patterns revealed reactivity only against viral protein VP1 for sera from both animals. Comparative immunoblotting patterns showed differences in the electrophoretic mobilities of viral protein VP1, especially for the Montpellier 76.1262 wild-type strain. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of [35S]methioinine-labeled viral polypeptides revealed that the two variant strains, Montpellier 76.1262 and Thionville 86.222, exhibited significant and reproducible shifts in the relative mobilities of VP1 and VP3 and, to a lesser extent, in those of VP0 and VP2. The relative mobility of VP4 seemed very similar for the JV-4 reference strain and the two variants. Interestingly, the structural differences in VP1 and VP3 of Montpellier 76.1262 were not correlated with the pattern of neutralization by monoclonal antibodies, unlike in our previous study, in which this strain differed from the prototype strain in only two epitopes. We concluded that, in addition to the heterogeneity of their biological and antigenic properties that we observed previously, echovirus type 25 wild-type strains may exhibit differences in their structural proteins.

Animals

Reciprocal productive and restrictive virus-cell interactions of immunosuppressive and prototype strains of minute virus of mice.

Viral and cellular factors responsible for parvovirus target cell specificity have been examined for two serologically indistinguishable strains of the minute virus of mice which infect mouse cells of dissimilar differentiated phenotype. Both the prototype strain and the immunosuppressive strain grow in and form plaques on monolayers of simian virus 40-transformed human fibroblasts, a finding that has allowed the comparison of several aspects of their virus-host cell interactions. Although closely related by antigenic and genomic criteria, both the prototype strain and the immunosuppressive strain are restricted for lytic growth in each other's murine host cell, that is, in T cells and fibroblasts, respectively. The host range of each virus variant appears to be specified by a genetic determinant that is stably inherited in the absence of selection. In the restrictive virus-host interaction lytic growth is limited to a small or, in some cases, undetectable subset of the host cell population, and the majority of the infected cells remain viable, continuing to grow at the normal rate without expressing viral antigens. The susceptible host cell phenotype is dominant in T lymphocyte x fibroblast fusion hybrids, implying that different cell types express different developmentally regulated virus helper functions that can only be exploited by the virus variant that carries the appropriate strain-specific determinant.

Animals

The S2 gene nucleotide sequences of prototype strains of the three reovirus serotypes: characterization of reovirus core protein sigma 2.

The S2 gene nucleotide sequences of prototype strains of the three reovirus serotypes were determined to gain insight into the structure and function of the S2 translation product, virion core protein sigma 2. The S2 sequences of the type 1 Lang, type 2 Jones, and type 3 Dearing strains are 1,331 nucleotides in length and contain a single large open reading frame that could encode a protein of 418 amino acids, corresponding to sigma 2. The deduced sigma 2 amino acid sequences of these strains are very conserved, being identical at 94% of the sequence positions. Predictions of sigma 2 secondary structure and hydrophobicity suggest that the protein has a two-domain structure. A larger domain is suggested to be formed from the amino-terminal three-fourths of sigma 2 sequence, which is separated from a smaller carboxy-terminal domain by a turn-rich hinge region. The carboxy-terminal domain includes sequences that are more hydrophilic than those in the rest of the protein and contains sequences which are predicted to form an alpha-helix. A region of striking similarity was found between amino acids 354 and 374 of sigma 2 and amino acids 1008 and 1031 of the beta subunit of the Escherichia coli DNA-dependent RNA polymerase. We suggest that the regions with similar sequence in sigma 2 and the beta subunit form amphipathic alpha-helices which may play a related role in the function of each protein. We have also performed experiments to further characterize the double-stranded RNA-binding activity of sigma 2 and found that the capacity to bind double-stranded RNA is a property of the sigma 2 protein of prototype strains and of the S2 mutant tsC447.

Amino Acid Sequence

The prototypical Epstein-Barr virus-transformed lymphoblastoid cell line IB4 is an unusual variant containing integrated but no episomal viral DNA.

IB4 is a prototype, latently Epstein-Barr virus (EBV)-infected, lymphoblastoid cell line. We show here that IB4 contains only integrated EBV genomes. Episomal EBV DNA is not detected by Gardella gel analysis or in situ hybridization. Restriction enzyme mapping indicates that the EBV genomes first circularized and then integrated into and deleted part of the BamHI C fragment. IB4 is therefore the only lymphoblastoid cell line described to date that lacks episomal EBV and has integrated EBV genomes with joined ends. Thus, the detection of joined EBV termini on Southern blots is not as reliable as the Gardella gel system for detecting episomal EBV DNA, and IB4 is not an ideal prototype cell line for the study of latent infection by EBV.

B-Lymphocytes

Nematode burdens and productivity of grazing cattle treated with a prototype sustained-release bolus containing ivermectin.

One hundred and twenty four-month-old Hereford-Friesian cross heifers weighing from 88 to 130 kg were divided into two equal groups. One group acted as a control with each animal receiving one placebo bolus, the other animals received one prototype intraruminal sustained-release bolus designed to deliver approximately 8 mg ivermectin/day for 100 to 120 days. The boluses were administered the day before turnout in mid-May. Each group was grazed separately for 167 days on pastures contaminated with parasitic nematode larvae including the lungworm Dictyocaulus viviparus, and the gastrointestinal worms Ostertagia ostertagi, Cooperia oncophora and Nematodirus helvetianus. Parasitic disease did not occur in the ivermectin-bolus group, but the control group required anthelmintic treatment to control parasitic gastroenteritis at 111 and 154 days after turnout. Up to the 111th day after turnout, the peak mean nematode egg and larval counts per gram of faeces in controls was, respectively, 564 epg and 0.5 lpg. Based on faecal nematode egg counts and worm burdens in bolus-treated cattle removed from pasture at 119 days after turnout and bolus function studies, it was concluded that ivermectin delivery from the prototype bolus ceased between 95 and 98 days after administration. However, unlike the controls, the treated cattle did not develop parasitic gastroenteritis at any time. Their faecal nematode egg output was significantly (P < 0.01) lower (< 1 epg) compared to the controls and lungworm larval output zero during the functional life of the bolus. The faecal egg and larval outputs continued low until the end of the trial.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Trait and behavioral prototypes of personality disorder.

The author reports a survey of the clinical features used by psychiatrists to diagnose personality disorders. The purpose was to develop definitions of these disorders and to identify behavioral features that could be used as diagnostic criteria. Psychiatrists rated trait and behavioral items describing each disorder for the degree to which they were prototypical of the disorder. Judgments of the prototypical quality of traits and behaviors were found to be equally reliable. Given that behavioral criteria require less inferential judgment, subsequent revisions of criteria to assess personality disorders can employ behavioral criteria in the expectation of improved reliability without loss of validity.

Adult

RXPERT: a prototype expert system for formulary decision making.

OBJECTIVE: RXPERT, a prototype, computer-based, expert system that models the decision-making processes for an ambulatory (non-hospital) formulary, is described as an example of how expert systems may be used to support pharmacy decision making. Basic information about expert-system technology is provided through this example. BACKGROUND: Computer-assisted decision making is becoming an important and accepted aspect of complex, health-related decisions. Because expert-system support may become an integral component of future, complex, pharmacy decision making, it is important for pharmacists to become familiar with this technology and its possibilities for supporting pharmacy decisions. METHOD: Expert systems offer the potential advantages of making the human decision-making process explicit, more consistent, easily duplicated in many locations simultaneously, and easy to update and document. Although an expert system is seldom intended to replace human decision makers, it can provide valuable support for complex, multivariable decisions. Typical knowledge-acquisition and knowledge-engineering techniques, as well as the characteristics and structure of expert systems, are described, relative to the development of the RXPERT prototype. CONCLUSIONS: Although RXPERT is not yet in use, the process for using an expert system to support an individual committee member's personal assessment of a drug product is described. Decision-support expert systems are potentially useful to pharmacists in complex decision-making tasks.

Canada

Talonavicular joint surface anatomy and prototype resurfacing prostheses.

The curvature and extent of a joint surface largely determine the type and range of motion possible. The talonavicular surface anatomy of 10 human foot specimens has been determined quantitatively, and the data have been compared with the design parameters for a prototype prosthetic joint. It was found that, in general, the natural talus as compared with the navicular was slightly larger in surface area and in mean arc length, but slightly smaller in mean radius of curvature. The arc length of the joint was found to be generally slightly longer along an axis positioned from slightly medial of dorsal to slightly lateral of ventral. In contrast, no general orientation of the radius of curvature was observed. Also, it was found that the congruency between the talus and navicular surfaces, as indicated by corresponding radii of curvature, varied widely. In comparison to the human specimens, a previously designed prototype talonavicular prosthesis proved somewhat smaller in radius, arc length, and surface area. Experimental studies related to other prosthesis design parameters, besides type and range of motion, are in progress.

Female

MCMI-II diagnosis of borderline personality disorder: base rates versus prototypic items.

The Millon Clinical Multiaxial Inventory-II (MCMI-II) profiles of 26 psychiatric inpatients diagnosed as having borderline personality disorders were compared with profiles of 42 patients with no personality disorders. The borderline group scored significantly higher on the following scales: Disclosure (X), Debasement (Z), Passive-Aggressive (8A), Self-Defeating (8B), Borderline (C), and Major Depression (CC). Differences approaching significance were also found on substance abuse measures: the Alcohol Dependence (B) scale and Drug Dependence (T) scale. These findings are consistent with criteria established in the Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev. [DSM-III-R]; American Psychiatric Association, 1987) and the results of other studies utilizing the MCMI-II. In addition, diagnostic efficiency of Scale C was assessed at various cutoff points defined by either base rate (BR) scores or the number of prototypic items endorsed. The greatest efficiency was found when a cutoff of seven or more prototypic items was utilized, with nearly 80% of the patients correctly classified. Results are discussed in terms of their relevance for further research.

Adult

Studies on the development of an ELISA kit for microbiological monitoring. 1. Evaluation of the reliability of the prototype kit by field tests.

The prototype of an ELISA kit using protein A as the second reaction reagent for mice and anti-rat IgG for rats was prepared for seromonitoring of the Sendai virus and mouse hepatitis virus (MHV)/sialodacryoadenitis virus (SDAV)/Parker's rat coronavirus (PCV) infections. The respective antigen strains and protein concentrations were Sendai virus MN strain, 2 micrograms/ml and MHV Nu-67 strain, 5 micrograms/ml. The reliability of this prototype kit was investigated in two field tests performed on a total of 10,094 mouse and rat sera from 147 institutions. The results indicated that the two types of kits for the two species of animals were highly specific, but it is necessary to increase the detection sensitivity of the MHV antigen for the MHV antibody of mice and SDAV/PCV antibodies of rats.

Animals

The effect of prototype-based versus attribute-based presentation forms on the acquisition of a medical concept.

The purpose of this study was to determine the differential effect of two presentation-forms on the acquisition of the concept of shock. It is hypothesized that presenting a prototype facilitates learning and retention of the concept shock compared with verbally enumerating the attributes of the same concept. A group of 106 students from nursing education participated in the experiment. A matched group design guided the assigning of students to different instructional conditions. The instructional program consisted of expository texts, different types of questions and feedback. In the experimental condition eight videotaped typical cases of shock were incorporated in the program. Data-analysis resulted in confirmation of the hypotheses (p less than 0.01), i.e. new instances of shock were identified more frequently by students of the experimental group, while these students were also more able to list commonalities and differences between different cases of shock. This finding supports the prototype-paradigm in concept learning and implies the recommendation to organize lessons in clinical reasoning or diagnostic behavior around typical cases of concepts.

Concept Formation

Characterization of the viral RNA species of prototype dengue viruses.

Dengue virus isolates have been grown in the Igarashi clone C6/36 Aedes albopictus cells in amounts suitable for biochemical studies. Oligonucleotide fingerprint analyses have been used to characterize the virion 40 S RNA species of the four prototype dengue (DEN) serotype viruses: DEN 1, Hawaiian strain; DEN 2, New Guinea C strain (both insect and mouse brain passaged derivatives); DEN 3, H-87 strain; and DEN 4, H-241 strain. Comparisons of the largest oligonucleotides derived by ribonuclease T1 digestion of these 40 S DEN virion RNA species indicate that ther are few, if any, large oligonucleotides that are homologous between any two fo the four dengue prototype strains. Preliminary analyses of the 40 S RNA 5' terminal sequence of DEN 3 virion RNA indicate that it has the composition of m7GpppAmpXp.

Aedes

[Learning and prototype formation of artificial categories defined by multidimensional normal distributions].

In order to approximate the variety of natural categories, two kinds of stimuli whose attributes vary according to different multivariate normal distributions are generated on CRT screen. Twenty undergraduate and graduate students served as subjects. Subject's task was to discriminate the stimuli. Results revealed that subject's performance can be explained very well by the parameters of the distributions (Exp.1). Although in previous studies prototypes have been assumed to be the mean value or central tendency of category instances, there is another possibility, especially when two or more concepts are simultaneously learned, that they have attributes which are emphasized. This hypothesis was confirmed in Exp.2, using 30 undergraduates as subjects. It was argued that we must distinguish at least two kinds of prototypes: the one formed by the most frequent instances and the other the most discriminate in contrast with the other concepts.

Adolescent

DentLE. The Dental Learning Environment: a prototype demonstration.

DentLE, the Dental Learning Environment is a hypermedia software system being prototyped as part of a research and development project at the State University of New York at Buffalo School of Dental Medicine. The design seeks to reach beyond single discipline software or cases, and integrate a range of patient problems within a comprehensive dental knowledge base. The approach is to use computer and hypermedia technology to weave together the disciplines of dentistry so that learning occurs in relation to patients, as they appear in the real world. The DentLE system prototype allows the learner to explore information in all the disciplines related to patient problems, as well as other information including "blind alleys" and results of curiosity.

Computer-Assisted Instruction

[Hepatitis C virus: sequence homology of a European isolate and divergence from the prototype].

The polymerase chain reaction (PCR) detected specific hepatitis C viral (HCV) RNA sequences in liver biopsies from two patients with chronic hepatitis, in the tissue of a liver implantate, in plasma from four chronic non-A, non-B hepatitis (NANBH) patients and, for the first time, in an infectious anti-D-immunoglobulin preparation. A comparison of the viral sequences coding for a region for the nonstructural NS3 protein from the liver tissues revealed only a very small degree of sequence divergence on the cDNA as well as on the amino acid level (between 0 and 5%). The sequence similarities of the RNA isolated from plasma of the four chronic NANBH patients and the anti-D-immunoglobulin preparation were partly somewhat lower but altogether also high (between 90 and 100%). In contrast, all eight cDNA and amino acid sequences exhibited a significantly higher degree of divergence in comparison with the HCV prototype sequence (between 29 and 32%) than among themselves (between 0 and 10%). This unexpected high sequence similarity of the eight European isolates and their low homology to the Northamerican prototype sequence is indicative for the existence of different types of HCV. This will be important not only for epidemiological studies but also for the development of effective diagnostic procedures and vaccines. Concerning the pathogenesis of NANBH, a double infection or a helper mechanism has to be considered: in addition to the C virus, sequences of an other virus particle were found in the infectious IgG preparation as well as in the liver biopsies.

Amino Acid Sequence

CD-ROM prototype applications within the Department of Veterans Affairs.

The Department of Veterans Affairs (VA) has been actively involved in examining the benefits of Compact Disc Read Only Memory (CD-ROM) to its operations. Approximately twenty VA titles either have been produced or are scheduled for production by Summer of 1991. Both textual and database CDs have been prototyped. Several of the CDs have been integrated directly into the VA's MUMPS-based hospital information systems. Titles which contain patient information employ the Data Encryption Standard (DES) for sensitive information. A related project involves the installation of a system which allows common VDTs on the hospital system to access commercial CDs such as MEDLINE, PDR, and CCIS. The prototypes have been successful and very favorably received by users.

CD-ROM

AI/Consult: a prototype directed history system based upon the AI/Rheum knowledge base.

An expert system is designed which uses the AI/Rheum knowledge base as the basis for a directed workup system for rheumatological disorders. A Turbo Pascal prototype is demonstrated which, unlike AI/Rheum, permits entry by the clinician of a patient's chief complaint(s) and subsequently develops a dynamic differential diagnosis for this limited set of findings. The system restricts its line of questioning to those pertinent in order to rule in or rule out items on this dynamic differential diagnosis, and, unlike AI/Rheum, it provides immediate notification to the user when a critical mass of information has been entered in order to meet a diagnosis at one of the AI/Rheum criteria table's three levels of diagnosis (possible, probable, definite). Thus the system allows for a more rapid, focused decision making approach than does AI/Consult, while it follows the trend established by QMR in that it abandons the Greek Oracle problem solving approach and instead adopts a physician-assisted hypothesis investigation approach. The system is currently a prototype, without AI/Rheum's page oriented and mouse driven interface, and thus the total user interaction time may be longer than with AI/Rheum even though fewer user interactions (responses) are required. Plans for future development include optimization of the knowledge base to allow for more efficient, problem oriented questioning and modification of the knowledge base compiler in order to dynamically rule out diseases through the addition of three new levels of diagnosis in the knowledge base criteria tables.

Diagnosis, Computer-Assisted