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Biomedical subjects

B Levin

Publications and source records attributed to B Levin.

At least 271 records · Page 15Linked to original sources

The Coronary Artery Surgery Study (CASS). A critical appraisal.

The applicability of the Coronary Artery Surgery Study (CASS) to clinical practice is seriously hampered by the following findings. (1) The CASS randomized study applies to only a small minority of patients with coronary artery disease. Attempts to extend the conclusions of CASS to the vast majority of patients with coronary artery disease are unjustified. (2) The high percentage of crossover of the medical group made it impossible for CASS to accomplish its primary goal of contrasting medical and surgical treatment. (3) Despite the fact that crossover of medically assigned patients created a bias against surgical treatment, the observed mortality in the surgical group was still 31% lower than that in the medical group. (4) The failure of CASS to find this difference to be statistically significant must take into account the fact that the statistical power of CASS was so low that a real difference was likely to be overlooked. (5) The conclusion that patients similar to those in the study may safely defer operation is unwarranted and violates the principles of prospective study design. In addition, CASS failed to address the possibility that deferring operation may compromise long-term survival.

Angina Pectoris↗

Treatment of metastatic colorectal carcinoma with cisplatin and 5-FU.

Twenty patients with measurable metastatic colorectal carcinoma were treated every 3 weeks with cisplatin (100 mg/m2 iv) on Day 1 and 5-FU (1000 mg/m2/day by iv infusion over 24 hours) on Days 1-5. Seven patients were previously treated with chemotherapy. The mean performance status for all of the patients was 1.5 (Eastern Cooperative Oncology Group). None of the patients had an objective response to the chemotherapy; 11 patients had stable disease and nine had no response. This study demonstrates that the combination of cisplatin and 5-FU, administered at this dose and schedule, has minimal activity in patients with metastatic colorectal cancer.

Adenocarcinoma↗

Retinoic-acid-binding protein in normal and neoplastic human esophagus.

The concentration of cellular retinoic acid binding proteins (CRABP) was determined in the cytosol of normal esophageal tissue and in esophageal carcinomas. Unlike the reported results for human breast, colon, melanoma, or oropharynx cancers, the CRABP levels in esophageal cancers were either undetectable or contained levels of CRABP which were significantly lower than that of adjacent histologically disease-free tissue (P less than 0.005). Moreover, there was no difference between the normal mucosa of cancer or noncancer patients with regards to the CRABP concentration. The absence of CRABP in the cancer tissue was not dependent on the degree of differentiation. These results indicate that the CRABP disappears when the normal mucosa becomes malignant. If such a change is also demonstrated in known premalignant conditions of the esophagus, CRABP could serve as a diagnostic biochemical marker for early detection of this cancer.

Adenocarcinoma↗

Primary osteogenic sarcoma of the spine.

Primary osteogenic sarcoma of the spine is a rare tumor making up 0.85% to 2.0% of all osteogenic sarcomas. The majority (29/41) of previously reported cases have occurred in vertebrae affected by Paget disease or radiation exposure. Two cases of osteogenic sarcoma of the spine, one lumbar, the other thoracic, with no known predisposing factors are presented.

Adult↗

Chromosomes in human large bowel tumors. A study of chromosome #1.

Chromosome studies on 49 patients with large bowel adenocarcinomas showed abnormalities of chromosome #1 in 19 cases (39%). One had monosomy, 13 showed trisomy, and 5 cases had structural abnormalities. Eighteen patients had tumors on the right side of the colon; of these, only 3 had an abnormal #1 (17%); 16 of 28 tumors (57%) located on the left side had abnormalities of #1. The regions of consistent duplication of 1q were q24----q44? The presence or absence of changes of chromosome #1 may be useful as a prognostic indicator in large bowel cancer.

Adenocarcinoma↗

Abnormal goblet cell glycoconjugates in rectal biopsies associated with an increased risk of neoplasia in patients with ulcerative colitis: early results of a prospective study.

A group of 18 patients with stable ulcerative colitis involving the entire colon for at least eight years was subjected to a biopsy of normal appearing rectal mucosa and followed prospectively over four years for the development of either dysplasia or cancer. Goblet cell glycoconjugate structure was examined in the rectal biopsies using fluorescein conjugated lectins. At the beginning of the study, 13 of the 18 patients had abnormalities of goblet cell mucin or cytoplasmic glycoconjugates in the rectal biopsies. Dysplasia subsequently developed in six and carcinoma in one of these patients. Among the five patients with normal lectin binding studies in the initial rectal biopsies, colonic dysplasia has subsequently developed in one. The abnormalities seen in the rectal goblet cells resembled in part those previously seen in immature and neoplastic colonic cells. The dysplastic tissues all contained the form of mucin which has been found in other neoplastic colonic tissues. This preliminary report after four years of prospective study suggests that abnormalities of glycoconjugate structure may be associated with, and may precede, neoplastic events in the setting of chronic ulcerative colitis.

Colitis, Ulcerative↗

Pregnancy complicated by extrahepatic biliary tract carcinoma. A case report.

Carcinoma of the extrahepatic biliary tract rarely coexists with pregnancy. Survival of both mother and infant beyond the early puerperium has not been reported previously in such instances. We treated a patient for pregnancy complicated by cholangiocarcinoma, with a successful maternal and fetal outcome.

Adenoma, Bile Duct↗

Maternal smoking and trisomy among spontaneously aborted conceptions.

In a study of spontaneous abortions, we found an apparently robust association of trisomy with smoking that varies with maternal age. Among women under age 30, smoking either before or at the time of conception is less common in women aborting trisomic conceptions than in controls delivering at 28 weeks or later. Among older women, smoking is more common in women aborting trisomic conceptions than in controls. Our results point to an effect of smoking on the frequency of trisomic abortions that varies with age, and they suggest that the causes of recognized trisomic abortions differ in younger and older women.

Abortion, Spontaneous↗

Human large-bowel cancer: correlation of clinical and histopathological features with banded chromosomes.

Clinical and histopathological features were correlated with cytogenetic banding studies on direct preparations from 31 large-bowel tumors. An interesting relationship between the site and the karyotypes of the tumors was observed. There appears to be a progressive increase in chromosomal number and/or structural rearrangement as one progresses from proximal to distal large bowel. We suggest that these observations may be related to differences in function and micro-environment within different areas of the colon. Although it is not known what factors favor cytogenetic variability and instability on the left side or the presence of fewer abnormalities on the right side of the colon, it is evident that clonal karyotypic evolution may be important in the progression of large-bowel cancer. The brevity of follow-up precludes conclusions regarding the influence of karyotype on survival.

Cecal Neoplasms↗

Karyotypic findings in a colonic villous adenoma.

Chromosomes from a patient with a villous adenoma of the colon were examined in detail with fluorescent banding. Of the cells analyzed, 73% had a modal chromosomal number of 48-52. The karyotypic findings show clonal evolution, an additional chromosome #8 being the most frequent abnormality, suggesting that this may be the primary chromosomal change, but other changes such as loss of a Y chromosome and the presence of marker chromosome #1 with duplication of the long arm also were observed. Previous cytogenetic data on large-bowel tumors is summarized. We hypothesize that this chromosomal evidence suggests that tubular adenoma, villous adenoma, and adenocarcinoma may be interrelated steps of a growth disorder.

Adenoma↗

Chromosomal banding patterns in human large bowel cancer.

Cytogenetic banding studies were performed on direct preparations from 31 large bowel tumors. Twenty-eight of these were from primary sites and three from metastases. Some distinctive patterns were observed. The 31 tumors were separable into four groups: (1) Tumors with normal karyotypes (three cases); (2) tumors with simple gains of chromosomes (three cases); (3) tumors with gains, losses and structural aberrations (ten cases). Groups 1, 2 and 3 were all in the diploid range; and (4) tumors with hypotriploid-hypotetraploid karyotypes (15 cases). Non-random gains of several chromosomes, especially No. 8 and non-random losses of No. 17 were seen in this series. Thirteen cases had sex chromosome abnormalities. The most prominent structural abnormalities involved chromosomes No. 1 and No. 5. Marker chromosomes were sometimes absent, but when present ranged from simple translocations to the most complex rearrangements. Doubling of chromosome and/or marker chromosomes were prominent in Group 4. Double minutes were seen in all three metastatic tumors and three primary cancers. Premature chromosome condensation was observed in three cases in the hypotriploid-hypotetraploid group.

Chromosome Aberrations↗