Two-dimensional positional mapping of gastrointestinal sounds in control and functional bowel syndrome patients.

Computerized auscultation of the abdomen provides a noninvasive and quantitative method to investigate gastrointestinal function. Two-dimensional mapping of bowel sound sites of origin, to the surface of the abdomen, was accomplished through simultaneous recording with three electronic stethoscopes. Control, irritable bowel syndrome, and nonulcer dyspepsia groups were studied.

Enterotachogram analysis to distinguish irritable bowel syndrome from Crohn's disease.

Crohn's disease is often initially misdiagnosed as irritable bowel syndrome. The goal of this research was to determine if computerized auscultation (fasting enterotachogram analysis) could have a role in distinguishing between these diagnoses. Patients with irritable bowel syndrome, Crohn's disease, and a control group were enrolled in the study.

Computerized auscultation applied to irritable bowel syndrome.

The purpose of this study was to investigate the potential of a computerized auscultation method for providing an objective, quantitative measure characteristic of irritable bowel syndrome. Bowel sounds from irritable bowel patients and normal controls were digitized using an electronic stethoscope. Computerized analysis indicated that the character of the bowel sounds did not differ significantly between groups.

Digital imaging colposcopy: corrected area measurements using shape-from-shading.

The quantitative measurement of areas on the cervix is of interest to researchers studying the natural history of human papilloma viral lesions. Measurement of areas from images obtained through a colposcope are, however, inherently in error due to the image being a two-dimensional projection of a three-dimensional object. The ability to correct for these errors through use of digital imaging colposcopy and a practical application of a shape from shading algorithm was developed in this study.

Digital imaging colposcopy: basic concepts and applications.

The technique of colposcopy has changed little since the introduction of the green filter to improve viewing of vascular structures. However, the recent dramatic improvements in computer technology now make it practical to combine computerized image processing with colposcopy, which we have termed "digital imaging colposcopy." Image processing techniques permit contrast enhancement of features, such as white epithelium and abnormal vasculature.

Computer-assisted analysis of transrectal ultrasound images.

We have developed a microcomputer based system with an application specific software package which permits the direct digitization and analysis of transrectal ultrasound (TRUS) images. The system is highly flexible and enables access to a wide range of image analysis tools through relatively simple software modifications, which cannot be implemented using a standard ultrasound instrument. We have demonstrated the capability of the system by an analysis of a number of morphometric parameters and by a correlation of these measurements with the presence of prostatic cancer.

The computerized digital imaging colposcope: future directions.

A computer-aided colposcope has been developed for enhancement and analysis of colposcopic images. There are numerous possible applications of this system, including image archiving, image enhancement and processing, and quantitative measurements of various features in the images. In addition, a wide range of digital filters can be applied to the system that may be used to detail different aspects of the image.

Novel selection for tetracycline- or chloramphenicol-sensitive Escherichia coli.

A method for selecting tetracycline- or chloramphenicol-sensitive Escherichia coli cells from a population of predominantly resistant cells is described. This method depends on the inability of drug-sensitive cells to induce lambda receptors in the presence of chloramphenicol or tetracycline, protein synthesis-inhibiting drugs. The addition of bacteriophage lambda vir to a mixture of drug-sensitive and drug-resistant cells, induced for lambda receptors in the presence of tetracycline or chloramphenicol, preferentially kills the drug-resistant cells (which are capable of inducing lambda receptors).

Transcription of the major Drosophila heat-shock genes in vitro.

Active eukaryotic genes are more accessible to some proteins than bind DNA than are inactive genes. In order to probe the accessibility of the Drosophila heat-shock genes we have isolated nuclei from Drosophila tissue culture cells and have used these nuclei as templates for Escherichia coli RNA polymerase. With nuclei isolated from cells that had not been heat shocked, the synthesis of heat-shock RNA was not detected by hybridization to a DNA clone containing sequences from the major heat-shock region.

Activation of the major drosophila heat-shock genes in vitro.

Inactive Drosophila heat-shock genes of isolated diploid nuclei can be induced to a transcriptionally active state by exposure to cytoplasmic extracts from heat-shocked Drosophila cells. No effect was observed on histone gene transcription, and extracts from non-heat-shocked cells were ineffective. The factor in the cytoplasmic extract has been partially purified and characterized.

Deoxyribonucleic acid-membrane interactions near the origin of replication and initiation of deoxyribonucleic acid synthesis in Escherichia coli.

A previously reported salt-sensitive binding of deoxyribonucleic acid (DNA) to the cell envelope in Escherichia coli, involving approximately one site per chromosome near the origin of DNA replication, is rapidly disrupted in vivo by rifampin or chloramphenicol treatment and by amino acid starvation. DNA replication still initiates with this origin-specific binding disrupted, even when the disruption extends over the period of obligatory protein and ribonucleic acid synthesis that must precede initiation after release of cells from amino acid starvation. Thus the origin-associated membrane-DNA interaction is not necessary either for the initiation event itself or for the maturation of a putative initiation apparatus in E.

Identification of a biochemically unique DNA-membrane interaction involving the Escherichia coli origin of replication.

DNA-membrane complexes have been obtained from Escherichia coli by using a freeze-thaw lysis procedure that avoids lysozyme and detergents. Complexes made in this manner and containing DNA near the origin of replication are uniquely sensitive to ionic strength, Pronase, and trypsin. There is approximately one such complex per chromosomal origin.