Biomedical subjects

H Dytch

Publications and source records attributed to H Dytch.

8 recordsLinked to original sources

PubMed1997

HLA and mate choice in humans.

Evidence from studies in rodents suggests that mate selection is influenced by major-histocompatibility-complex haplotypes, with preferences for dissimilar partners. This study was initiated to determine whether avoidance of a mate with the same HLA haplotype as one's own might be occurring in the Hutterites, a North American reproductive isolate of European ancestry, notable for their large sibships, communal lifestyle, and limited number of five-locus HLA haplotypes (HLA-A, -B, -C, -DR, and -DQ). HLA haplotypes were known for 411 Hutterite couples. The number of couples expected to match for a haplotype was calculated in two ways: first, from population genotype frequencies, with account being taken of the nonrandom mating pattern with respect to colony lineages, and, second, from computer simulations using conservative founder assumptions and the exact genealogy of the 411 couples. We observed fewer matches for HLA haplotypes between spouses than expected (first method, P = .005; second method, P = .020-.067). Among couples who did match for a haplotype, the matched haplotype was inherited from the mother in 29 cases and from the father in 50 cases (P = .018). These results are consistent with the conclusion that Hutterite mate choice is influenced by HLA haplotypes, with an avoidance of spouses with haplotypes that are the same as one's own.

Adult↗

PubMed1992

Prognostic significance of ploidy determination in rectal cancer.

Between 1965 and 1981, 154 patients with potentially curable rectal adenocarcinoma underwent surgical treatment at the University of Chicago Medical Center. In 134 cases, enough histological material was available to perform determinations of DNA content by the cytophotometric method (n = 108), or by the flow cytometric technique (n = 109). In 83 cases, DNA content was analyzed in the same specimen with both techniques, and in 77 of these cases the sections obtained from the paraffin blocks were contiguous. When using flow cytometry, 62% of stage B and 74% of stage C lesions were classified as aneuploid on the basis of a DNA index greater than 1. This correlation was statistically significant (p = 0.002). Patients with diploid tumors had an actuarial five-year survival equal to 62% in comparison with a 46-51% five-year survival for patients with aneuploid tumors. This difference was not statistically significant and it was explained by the tendency for aneuploid tumors to be in an advanced histopathological stage.

Adenocarcinoma↗

PubMed1990

Karyometric marker features in normal-appearing glands adjacent to human colonic adenocarcinoma.

The expression of nuclear marker features in normal-appearing tissue adjacent to colonic adenocarcinoma was investigated. Formalin-fixed, paraffin-embedded tissue sections of colon from 9 patients with adenocarcinoma and from 9 normal controls were cut 4 microns thick, Feulgen stained, and measured by a cell image analysis system using a Matrox MVP-AT/NP imaging board. Thirty nuclei in the tumor region, 30 nuclei 2 mm into the histologically normal-appearing distal margin, and the same number at 5, 10, 20, and 50 mm into the margin were measured for each patient. An additional 30 nuclei were recorded from 9 patients each free from colonic disease. Nuclear features were selected to discriminate between tumor nuclei and nuclei from normal control subjects and between nuclei measured in the histologically normal-appearing margin next to the tumor and control nuclei. Eight micromorphometric measures were found to be statistically significantly different in nuclei measured in the margin site, including features describing staining density (total absorbance, average absorbance 20% below mean, average absorbance 20% above mean) chromatin texture (cooccurrence matrix, run length, and peripheral tendency) and nuclear area. The category differences are statistically highly significant.

Adenocarcinoma↗

PubMed1990

Artificial intelligence-guided analysis of cytologic data.

A design for the integration of artificial intelligence (AI) technology with large databases of clinical and objective cytologic data, such as are on file at the University of Chicago, is presented. Among the key features of this approach are the use of a knowledge representation structure based upon an associative network, the use of a Bayesian belief network as a method of managing uncertainty in the system, and the use of neural networks and unsupervised learning algorithms as a means of discovering patterns within this database. Such an automated approach is necessary, given the complexity and interdependence of these data, to gain an understanding of their dependence structure and to assist in their exploration and analysis.

Algorithms↗

PubMed1989

Correlation between automated karyometric measurements of squamous cell carcinoma of the esophagus and histopathologic and clinical features.

The clinical staging of esophageal carcinoma is unreliable currently, making it difficult to select patients for aggressive therapy. To further refine staging criteria, the nuclear characteristics of a series of 31 patients with squamous cell carcinoma of the esophagus were studied using a computerized image analysis system (MicroTICAS). Karyometric measurements, including total nuclear DNA content, nuclear area, and nuclear roundness were compared with various clinical and histologic variables. Nearly all tumors (30 of 31) were aneuploid. Tumors with nuclear areas greater than 70 microns2 were associated with transmural esophageal penetration (P less than 0.05) and to a lesser extent with poor survival (less than 6 months; P = 0.06). Surprisingly, nuclear ploidy did not correlate with either variable. These data support a role for nuclear analysis on preoperative biopsy specimens as an adjunct in clinical staging.

Aneuploidy↗

PubMed1988

Importance of tumor morphology for the long term prognosis of rectal adenocarcinoma.

A retrospective review of 149 consecutive potentially curable rectal adenocarcinomas operated on at our institution between 1965 and 1981 was carried out to assess whether tumor morphology influences long term survival. Complete follow-up was available on all patients and extended to 20 years. Data on tumor morphology was extracted from pathology reports and was available in 147 cases (98.6%). Tumors were defined as exophytic (n = 76) when exhibiting a polypoid growth pattern protruding into the lumen at least 1 cm; when lacking such characteristic growth pattern, tumors were classified under the general term of nonexophytic (n = 71). The 5 year survival rate calculated with life table analysis was 80 per cent for exophytic carcinomas and 54.1 per cent for nonexophytic tumors. This difference was verified by logistic regression analysis and proportional hazard technique and is statistically highly significant (P = 0.001). The rate of distant metastases was 29.7 per cent for exophytic adenocarcinoma and 48.6 per cent for nonexophytic tumors (P = 0.02). Although the results did not reach statistical significance, local recurrence of tumor occurred about twice as often in nonexophytic tumors (15.7%) compared with exophytic tumors (8.1%). Thus, we conclude that tumor morphology is an important preoperative prognostic factor for survival and prediction of distant metastasis, and possibly for local recurrence.

Actuarial Analysis↗

PubMed1987

Nuclear DNA analysis of insulinomas and gastrinomas.

The potential for malignancy of an islet cell tumor of the pancreas is difficult to cytologically judge when one evaluates only the primary lesion, because a malignant condition is usually determined by the presence of regional or distant metastases. Nuclear DNA cytometric measurements have proved helpful both in the evaluation of the malignant potential of other endocrine and nonendocrine lesions and in the determination of the "aggressiveness" of these tumors. Thirty-six islet cell tumors or their metastases from 25 patients were studied. Eleven patients had insulinomas and typical insulinoma syndromes, and 14 others had gastrinomas with the Zollinger-Ellison syndrome. Tissue from each tumor was stained by the Feulgen technique, and nuclear DNA cytometry was performed by means of the microTICAS system designed by the Cytopathology Laboratory of the University of Chicago. Ploidy measurements of insulinomas, taken alone, did not discriminate well between benign and malignant states. However, the single malignant insulinoma could be clearly recognized, for it was one of only two lesions in that group with 5N-exceeding rate (5N-ER) values of 1% or greater. (5N-ER is defined as the percentage of aneuploid nuclei with nuclear DNA content greater than 5N.) On the other hand, seven of eight malignant gastrinomas had ploidy values of 2.5N or greater (our definition of an aneuploid state) and/or had 5N-ER values of 1% or greater, while five of six benign gastrinomas had ploidy values of less than 2.5N and had 5N-ER values of 0%. In addition, the two most aggressive tumors had the highest ploidy and 5N-ER values. Nuclear DNA cytometric studies appear to offer promise as an aid in the evaluation of pancreatic islet cell tumors, particularly gastrinomas.

Adenoma, Islet Cell↗

PubMedDate not supplied

The value of measurement of ras oncogenes and nuclear DNA analysis in the diagnosis of Hürthle cell tumors of the thyroid.

Hürthle cell tumors (HCT) remain difficult to treat because some which appear non-malignant on light microscopy later metastasize. In order to improve diagnostic accuracy, the value of ras mutations and nuclear DNA analysis was determined in 65 patients with HCT. Rapid nuclear DNA cytometry (MicroTICAS system) was performed. Mutations of H-ras, K-ras, and N-ras genes were analyzed by oligonucleotide probe hybridizations to polymerase chain reaction (PCR) amplified DNA. HCT were classified by light microscopy as benign (n = 22), intermediate (n = 30), and malignant (n = 13). After a mean follow-up of 7 years, 1 (4.5%) of 22 benign tumors and 4 (13%) of 30 intermediate tumors had metastasized, leading to tumor death in 3 of these 5 patients. Six of the 13 cancers diagnosed by light microscopy also resulted in tumor-related deaths. Aneuploidy was found in 83% of all Hürthle cell cancers, including 3 (60%) of the 5 cancers not diagnosed microscopically. However, 49% of non-malignant HCT also demonstrated aneuploidy. A nuclear area of less than 55 square microns was found in 83% of all Hürthle cell cancers and in 100% of those cancers not diagnosed by light microscopy. However, 47% of non-malignant HCT also demonstrated a "small" nuclear area. Aneuploidy correctly identified 8 of 9 cancers that resulted in tumor death and each of 3 other tumors that developed metastases. However, 1 patient with a diploid tumor died of metastatic cancer. A nuclear area of less than 55 square microns identified each cancer that resulted in a tumor death.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗