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Biomedical subjects

J B Gregg

Publications and source records attributed to J B Gregg.

At least 19 recordsLinked to original sources
PubMed1996

An interactive decision support system for breast fine needle aspiration cytology.

OBJECTIVE: To develop a computerized system to assist in the diagnosis of malignancy in breast fine needle aspiration cytology. STUDY DESIGN: A Bayesian belief network was designed to control uncertainty and allow a diagnostic decision to be reached based on the sequential collection of cytologic information. Ten cytologic features were defined as clues that contribute to the diagnostic discrimination of benign and malignant aspirates. The impact of each feature on the diagnostic decision was quantified by a conditional probability matrix. RESULTS: For the assessment of a new case, the computer guides the user through the diagnosis, prompting him or her for information on each of the diagnostic features in turn. For each feature, the user is presented with a series of digitally stored color microscopic images that have been selected to represent good examples of the different feature grades-e.g., pleomorphism: none, mild, moderate and severe. Each image is mapped to an overlapping curve, and by positioning a line on the spectrum where the user feels the case lies, a membership function vector is calculated and entered as evidence into the network. This results in an update in the belief in the diagnostic alternatives. After all the clues have been assessed, a final diagnostic probability is reported. In addition, a cumulative belief curve can be drawn that maps the change in the diagnostic probabilities after each piece of evidence has been submitted, providing unique insight into the diagnostic process. CONCLUSION: Systems like this represent an important step forward in the use of descriptive classifiers. They impose consistency in terminology, improve reproducibility in the grading of cellular abnormalities and remove subjectivity in interpreting the significance of pvisual clues to diagnosis. As such, they represent a necessary tool in pathologic decision making.

Biopsy, Needle↗
PubMed1990

Ancient temporal bone osteopathology.

Few isolated specimens or series of temporal bone abnormalities from antiquity are reported from North America. Infections were in the past and are today the most common otologic problems. Differentiating infectious disease residua from other causes of osteopathology has proven difficult for some not conversant with disease pathophysiology. During clinical experience spanning five decades and research involving several thousand aboriginal skeletons, data relating to temporal bone disease were accumulated. As a didactic exercise, findings in 18 illustrative temporal bones encountered during research are presented and discussed briefly.

Adult↗
PubMed1989

Palatal migration of two mesodens in a prehistoric Tennessee Indian: a case for the blood vessel thrust theory of tooth movement.

The skull of a prehistoric, Middle Mississippian, American Indian shows two mesodens that migrated to the distal margin of the palate. These teeth are positioned in such a way as to avoid the most common intraoral forces affecting tooth movement. The resorption of the palatal bone, distal to the teeth indicates movement caused by forces predicted by the Blood Vessel Thrust Theory.

Adult↗
PubMed1989

Whither scientific investigation.

Reburial of bones uncovered by archeological exploration has become a major focus for some groups. Excavations in the Dakotas, prior to the closure of the Missouri River dams, yielded much information on demographics, anomalies, and epidemiological patterns for specific abnormalities in prior inhabitants of the area over several centuries. Physicians as well as others should be aware of the importance of such work and of the need to control the present anti-science campaign.

Humans↗
PubMed1988

Arikara Indians.

Explore the source record for details and available documents.

Adult↗
PubMed1982

Mastoid development in ancient and modern populations. A longitudinal radiological study.

The effect of otitis media on the human mastoid process in a common milieu over a millennium was evaluated by comparing two present and four ancient populations. Temporal bone pneumatization patterns indicate that otitis media and mastoiditis existed in antiquity, and there were more altered pneumatization patterns in skulls from the era following European contact than from eras before European contact. Pneumatization patterns were similar in ancient skulls and in a preponderantly white male population mostly born before antibacterial availability. Both ancient and modern pre-antibacterial era temporal bones show more effect of otitis media during childhood than is found in present day schoolchildren. Reasons for differences are explored. It is inferred that upper respiratory tract infections were prevalent in the Upper Missouri River Basin during the past millennium. Furthermore, microbiological agents with virulence similar to today's flora were prevalent in this region more than 1,000 years ago.

Adolescent↗
PubMed1982

Unusual osteolytic defects in ancient South Dakota skulls.

Unusual osteolytic defects in eight skulls culled from over 4000 ancient South Dakota burials are presented, discussed briefly, and assigned to what we think is their most likely cause. Because these are collection skeletons, histological and microbiological and microbiological confirmation of interpretations concerning specific lesions are not possible. Corroboration of our opinions has been sought through radiographs and by expert consultation elsewhere. Although our opinions are interpretative and subject to rebuttal, they can serve as a base for future research if and when similar specimens are discovered elsewhere. In addition, these specimens are indicators of other than usual ancient skull pathology from a limited geographic area, representing people who lived there during a known time frame.

Adult↗