Search PubMed⌕ Search

Biomedical subjects

D F Cruess

Publications and source records attributed to D F Cruess.

At least 37 records · Page 2Linked to original sources
PubMed1992

Distant metastasis from a carcinoid tumor of the appendix less than one centimeter in size.

The presentation and management of a patient with liver metastasis from a 0.6 cm carcinoid tumor of the appendix is presented. This is the first documented case of distant metastasis from a carcinoid of the appendix less than 1 cm in size. Histopathologic, immunohistochemical, and electron microscopic studies support the appendiceal carcinoid as being the primary neoplasm. Invasion of the mesoappendix was the only finding to suggest potentially aggressive behavior. We reviewed the literature and found 414 previously reported cases that provided complete information regarding tumor size, mesoappendiceal invasion, and presence of metastasis. For the entire group the frequency of metastasis was related to tumor size greater than 2 cm (p less than 0.0001) and invasion of the mesoappendix (p less than 0.0001). After dividing the group based on size, mesoappendiceal invasion was related to metastasis in those tumors less than 2 cm in size (p less than 0.0001) but not in tumors larger than 2 cm (p = 0.1538).

Appendiceal Neoplasms↗
PubMed1991

Effects of aspirin, dipyridamole, and dibutyryl cyclic adenosine monophosphate on platelet-derived growth factor A chain mRNA levels in human saphenous vein endothelial cells and smooth muscle cells.

Aspirin and dipyridamole have frequently failed to control intimal hyperplasia in vascular grafts in animal and clinical trials. These trials were based on the concept that the smooth muscle mitogen, platelet-derived growth factor (PDGF) released from platelets, was a major cause of intimal hyperplasia. Both endothelial and smooth muscle cells (ECs and SMCs), however, can also release PDGF-like SMC mitogens that might cause intimal hyperplasia. We therefore tested whether aspirin and dipyridamole alone or together can affect PDGF-A chain mRNA levels in cultured human saphenous vein ECs and SMCs. Cultures were exposed for 72 hours to 3 x 10(-5) mol/L aspirin and/or 5 x 10(-6) mol/L dipyridamole. Cellular RNA was then extracted, and PDGF-A chain mRNA signal levels were measured by a reverse transcription/polymerase chain reaction method. mRNA for glyceraldehyde-3-phosphate dehydrogenase was used as a constitutively expressed control RNA species. Signal strength on Southern blots of amplified polymerase chain reaction products was measured by densitometry. Neither aspirin nor dipyridamole alone or together reduced the ratio (PDGF-A chain signal/glyceraldehyde-3-phosphate dehydrogenase signal) below that of control cultures. PDGF-A chain expression was not a constitutive artifact of culture because dibutyryl cyclic AMP (5 x 10(-4) mol/L) reduced PDGF-A chain signal from a control index of 1.0 to 0.5 +/- 0.1 (mean +/- SE) (n = 3; p less than 0.05) in EC cultures and to 0.2 (mean) (n = 2) in SMC cultures. These data may explain why aspirin and dipyridamole fail to reduce intimal hyperplasia in some animal and clinical trials despite effective inhibition of platelet aggregation.

Aspirin↗
PubMed1991

The effects of glaucoma medications on Tenon's capsule and conjunctiva in the rabbit.

Glaucoma filtering surgery fails most frequently due to fibrosis at the episcleral-conjunctival/Tenon's capsule interface. Sherwood et al have suggested that chronic topical antiglaucoma medications increase conjunctival inflammatory cells, which could increase the likelihood of fibrosis and subsequent bleb failure. In a pilot study in a rabbit model, we placed timolol, pilocarpine, and epinephrine, or a combination of all three, in one eye of 24 animals twice daily for 7 months. The fellow eye received distilled water. Microscopic examination revealed no statistically significant change in the number of acute or chronic inflammatory cells, fibroblasts, or goblet cells in the treated as compared with the control eyes. A longer duration of drug administration, or drug administration followed by surgical intervention, may be required to produce an effect on the conjunctiva and Tenon's capsule, if such an effect exists.

Administration, Topical↗
PubMed1991

Adenocarcinoma of the colon and rectum in patients less than 40 years of age.

From 1962 to 1988, 50 of 801 patients with adenocarcinoma of the colon and rectum treated at the National Naval Medical Center were less than 40 years old. Symptoms were present in 47 of the younger patients at presentation. The mean duration of time from the onset of symptoms to diagnosis in this group was 4.9 months. Risk factors for carcinoma of the colon and rectum were identified in 14 of 50 patients less than 40 years old. A significantly greater proportion of patients less than 40 years old had Stage C disease compared with the older group of patients (42 versus 22 per cent, p = 0.014). Stage B disease was more common in patients more than 40 years of age (44.8 versus 26.0 per cent, p = 0.014). The proportion of patients with Stages A and D disease was similar in both age groups. The cumulative survival rate in this group at five and ten years was 43 and 34 per cent, respectively. The five year survival rate in patients less than 40 years old with Stage B disease was 76 per cent and with Stage C disease, 37 per cent. All young patients with Stage D disease were dead at 28 months. Synchronous and metachronous carcinomas of the colon and rectum were uncommon in patients less than 40 years old. Patients less than 40 years of age with carcinoma of the colon and rectum are usually symptomatic and have advanced disease at the time of presentation. Survival time for these patients for each stage of disease is similar to the over-all population of patients with carcinoma of the colon and rectum.

Adenocarcinoma↗
PubMed1990

Epidemiology of human immunodeficiency virus in families in Lusaka, Zambia.

Persons living in the same household as index patients with AIDS or ARC in Lusaka, Zambia were clinically and serologically evaluated for HIV-1 infection. In the 150 households of male index cases, 92 (61.3%) of their spouses were infected, compared with 57 (73.1%) of the spouses of the 78 female index cases. The more advanced the clinical stage of illness in the index cases, the greater the probability of HIV infection in the spouse (RR = 4.44), and the more likely the spouse was symptomatic. Four of the 11 spouses who seroconverted to HIV had also had sexual intercourse at a time when their HIV-infected partner had genital ulcers (RR = 7.45). Of 144 children under 5 years of age, 36 (25.0%) were infected, all had infected mothers and were the last to be borne in all but one household. Three of 120 children 5 to 10 years of age were also infected, presumably through perinatal transmission. Forty-six of 52 discordantly infected couples followed for 1 year continued to have unprotected vaginal intercourse, and 11 (21.2%) of these seroconverted to HIV. There were no HIV infections that could be attributed to transmission by other means than heterosexual intercourse between spouses or by perinatal infection in children borne of infected mothers. The study suggests that there is an increasing risk of HIV heterosexual transmission as infection progresses in the infected partner, and that more effective counseling is needed to prevent it.

AIDS-Related Complex↗
PubMed1989

Selecting radiology resident candidates.

Radiology resident candidate selection has become a burdensome, subjective, and somewhat arbitrary process. Because the luxury of many well-qualified candidates exists, there is an obligation to select them as honestly, equitably, and objectively as possible. Two years were spent in revising and modifying the resident selection process to make it more uniform and more efficacious. An application scoring form was devised to extract uniform pertinent information from the original application form. Candidates could then be ranked according to a numerical score derived from the form. This allowed easy selection of top candidates to be interviewed. A new interviewing scoring form was developed to include desirable characteristics of resident candidate performance. This form was also devised in such a way as to be easily scored and to allow selection of the top 20 to 25 candidates. These candidates were then ranked by participating faculty members while reviewing their application score forms and their interview forms. Positions for the residency training program were offered according to the ranking. The usefulness of both new forms was evaluated and confirmed by correlating form scores with faculty ranking of academic performance of current residents in the training program.

District of Columbia↗
PubMed1989

Review of use of statistics in The American Journal of Tropical Medicine and Hygiene for January-December 1988.

A statistical review of all 201 scientific articles published during the calendar year 1988 in The American Journal of Tropical Medicine and Hygiene was made to determine the type of study published by the journal, the level of statistics that was employed by the published articles, and the extent of common statistical errors. Sixty-five (32%) of the articles were classified as experimental, with most of the remaining observational studies classified as cross-sectional in design. A reader with the knowledge of only simple descriptive statistics would be able to understand 60% of the statistical procedures used in the published papers. Knowledge of the usual components of a single semester course in introductory statistics increases understanding to 91% of the techniques used. It was determined that 148 (73.5%) of the 201 articles had at least 1 detectable statistical error; most of these errors involved improper documentation or application of statistical hypothesis testing. The most common descriptive statistical error was the misuse of the concepts of "standard deviation" and "standard error" which was found in greater than 20% of the articles. Examples of each of the common statistical errors seen are given with suggestions for improvement.

Analysis of Variance↗
PubMed1989

A survey of infants with neonatal sepsis in U.S. Army hospitals.

Data on 109,312 singleton births at U.S. Army hospitals over 3 years were examined to determine differences in perinatal risk factors between infants with a diagnosis of sepsis confirmed by blood culture and those whose cultures remained negative. The incidence of confirmed sepsis (1.1/1000 live births) and the importance of perinatal complications and prematurity were consistent with other reported findings. No reliable indicators of bacteremia that could be used in conjunction with other clinical data were found. These findings support continued empiric therapy in infants at risk until infection can be verified by culture.

Escherichia coli Infections↗
PubMed1988

Expression of genes for platelet-derived growth factor in adult human venous endothelium. A possible non-platelet-dependent cause of intimal hyperplasia in vein grafts and perianastomotic areas of vascular prostheses.

Neointimal fibromuscular hyperplasia (NFH) in vein grafts and perianastomotic zones of vascular prostheses has been attributed to the effects of platelet-derived growth factor (PDGF) released by platelets interacting with bypass conduits. But inhibition of platelet aggregation often fails to prevent NFH, and recurrent growth of intact, platelet-free endothelium over perianastomotic areas where NFH occurs is inconsistent with the concept of sustained PDGF release from platelets causing NFH progression at late times after surgical procedures. Cultured bovine aortic endothelial cells (ECs) and human umbilical vein ECs have been shown to release a PDGF-like molecule. We report that confluent cultured fourth passage adult human saphenous vein ECs (AHSVECs) grown in the presence of heparin (100 micrograms/ml) and retina-derived growth factor (RDGF) studied by Northern blotting transcribed a messenger ribonucleic acid (mRNA) of 3.9 kb, strongly hybridizing to PDGF B chain probes, and two species of 2.0 and 2.6 kb hybridizing to PDGF A chain probes. Withdrawal of RDGF and heparin from these cultures for 48 hours before mRNA extraction amplified the scanning densitometric mRNA signal per cell by 8.0 +/- 7.6 fold (mean +/- SD) (N = 4 cultures) for B chain mRNA and 5.2 +/- 3.6 fold (N = 3 cultures) for A chain mRNA. In addition, AHSVEC cultures released a PDGF-like substance, because 50% vol/vol AHSVEC-conditioned serum-free medium increased tritiated thymidine uptake elevenfold in PDGF receptor-bearing 3T3 cells whereas an excess (50 micrograms/ml) of nonspecific goat anti-human-PDGF antibody significantly reduced this increase by a mean of 30% to 7.0 +/- 3.4 fold (N = 6 trials, p less than 0.001). Flow cytometry determined AHSVEC cultures to be proliferating with a mean of 6.2% +/- 1.9% (N = 3 culture lines) of ECs in S phase even at confluence when deprived of EC mitogens for 48 hours. Adult human ECs, which proliferate on bypass conduits and host vessels after perioperative injury, may play a role in causing NFH by stimulating proliferation of adjacent smooth muscle cells. Prevention of NFH may require not only antiplatelet agents but also ways to prevent EC release of smooth muscle cell mitogens in response to perioperative EC injury.

Animals↗
PubMed1988

Ranking: a year three follow-up in a different institution.

Ranking residents as a means of semiobjective evaluation of their overall performance was described in 1985. The predictive nature of pooled faculty ranking of residents was stressed. Ranking of resident total scores on The American College In-training Examination and American Board of Radiology written examination was noted to be statistically related to the pooled faculty ranking. Similarly, the faculty ranking was predictive of itself in subsequent rankings. A cohesiveness of faculty consensus was present such that small numbers (five minimum) were predictive of larger groups of participating faculty. All reported observations persist in the new institution. Exceptions to expected residency level of training stratification (eg, third-year residents ranking in the midst of first-year residents, second-year residents ranking above many third-year residents) continue to be the most useful observation in counseling residents. Additional information reported includes sensitivity of the ranking to improvement or nonimprovement of probated residents.

Achievement↗
PubMed1987

Pyridoxine deficiency and ethanol-induced liver injury.

It has been suggested that pyridoxine deficiency may potentiate ethanol-induced liver injury. Our purpose was to clarify the effect of pyridoxine deficiency on ethanol-associated liver injury by comparing liver histology, serum liver enzymes, and the viability of cultured hepatocytes from pyridoxine-deficient and pyridoxine-sufficient rats that had been chronically fed ethanol-enriched diets. Our data fail to substantiate that pyridoxine-deficient animals are more susceptible to the hepatotoxic effects of ethanol than pair-fed pyridoxine-sufficient controls. Furthermore, the addition of pyridoxine to hepatocyte cultures fails to prevent in vitro cytotoxicity of added ethanol. Pyridoxine deficiency may augment ethanol-induced enhancement of hepatic urea synthesis. These data suggest that pyridoxine deficiency may contribute to the abnormal plasma amino acid profiles and nitrogen balance of chronic alcoholics, but that it does not potentiate ethanol-induced liver injury.

Animals↗