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Biomedical subjects

R Lev

Publications and source records attributed to R Lev.

At least 19 recordsLinked to original sources
PubMed2001

The unpredictability of seal after post space preparation: a fluid transport study.

A root canal filling remaining after post space preparation is commonly expected to provide adequate seal. Coronal leakage of 30 endodontically treated teeth was measured before post space preparation using a fluid transport assay. In 10 of these teeth post space was prepared, using a two-step procedure, first to a remaining filling of 6 mm and then to 3 mm, with the leakage studied after each step. In 10 teeth the removal was done in one step to a remaining length of 3 mm. The other 10 teeth, with intact root canal fillings, served as controls and were tested twice for leakage. A significant difference was found between the sealing ability of intact fillings and that of partially removed ones (p < 0.05). The difference between the sealing ability of 3 and 6 mm remaining length group was not statistically significant. The lack of statistical differences between the 6 mm and 3 mm fillings was due to a great variability which existed among the 3 mm remaining fillings. These results suggest that 3 to 6 mm fillings provided a seal inferior to that of intact root canal fillings. Reduction of the fillings to 3 mm resulted in an unpredictable seal.

Analysis of Variance↗
PubMed2001

Collagenous gastritis associated with lymphocytic gastritis and celiac disease.

Collagenous gastritis is a rare disorder, with only 8 cases reported in the literature, 2 in children and 6 in adults. We report an additional case of collagenous gastritis in a 42-year-old man with celiac disease. A thickened (>10 microm) subepithelial collagen band with entrapped capillaries, fibroblasts, and inflammatory cells was seen in the stomach, associated with lymphocytic gastritis. The duodenal mucosa showed severe villous atrophy but no subepithelial collagen deposition. No evidence of lymphocytic or collagenous colitis was found in the colon. The patient became symptom-free on a gluten exclusion diet and showed partial improvement of histopathologic findings after 3 months. Collagenous gastritis is a rare disease, but a wider recognition of its histopathologic features and clinical associations may bring more cases to light and provide additional clues in determining its etiology and pathogenesis.

Adult↗
PubMed2001

Extensive necrosis in renal cell carcinoma specimens: potential clinical and prognostic implications.

BACKGROUND: Extensive necrosis is rare in primary renal cell carcinoma. This finding may reflect the biological characteristics of the carcinoma and therefore could be of prognostic and clinical value. OBJECTIVES: To assess the incidence of necrosis in renal cell carcinoma and its potential prognostic value. METHODS: We conducted a consecutive retrospective study of 173 patients after radical nephrectomy for renal cell carcinoma. Clinical and pathological data were collected from hospital medical records and compiled into a computerized database. RESULTS: Extensive necrosis was found in 31 tumor specimens (17.9%). Univariate analysis showed that the specimens with extensive necrosis were significantly larger and manifested more perirenal and venous extension than the tumors without necrosis. The size of the renal tumor was the only parameter that remained significant in multivariate analysis (P = 0.0001). Overall disease-free survival did not differ significantly between patients with necrotic tumors and those without (68% and 66% respectively). CONCLUSIONS: The finding of extensive necrosis in renal cell carcinoma specimens does not seem to be related to tumor biology but rather may reflect the relation between size and vascularity of the tumor.

Adult↗
PubMed1999

Colon polyp registries and colorectal cancer control.

This cohort of 252 subjects in the Roger Williams Hospital Polyp Registry who had adenomatous polyps removed in 1990, was followed for 6 years. Thirty subjects died during that period. Follow-up rate for the 222 living patients (88.1% of total) was 85%. New adenomatous polyps were found in 59% of the endoscoped subjects. Risk factors for new polyps included family history of colorectal carcinoma (p = 0.00079), right-sided location (p = 0.0108), and (probably) prior adenomatous polyps (p = 0.0595). In addition, three colorectal carcinomas, two of which were Dukes stage A, were found 1, 1, and 6 years after index polypectomy. If, as is common practice, the two first-year cancers are excluded, the observed incidence of metachronous colorectal cancer was 0.8/1000 patient years, which is substantially less than the expected incidence of such carcinomas in reference populations. Compared to the 1984 and 1987 cohorts in the polyp registry, colonoscopy was used more frequently and sigmoidoscopy less so for surveillance. Within the sigmoidoscopy group, the flexible instrument continued to rise in popularity as compared with rigid sigmoidoscopy. In addition to helping reduce the incidence of metachronous colorectal carcinomas, the polyp registry also serves the educational function of sensitizing physicians and their patients to the need to detect and treat these premalignant lesions. Enrollees in the registry also provide a source for studies designed to evaluate possible inhibitory effects of dietary, chemopreventive, and other agents on colorectal neoplasias.

Adenomatous Polyposis Coli↗
PubMed1999

Marital quality among couples living under the threat of forced relocation: the case of families in the Golan Heights.

This study aims to explore how the long period of uncertainty about possible relocation affects the marital quality of the population in the Golan Heights and what forms of coping with this ongoing stress are used. The results, based on both quantitative and qualitative data, indicate a circular process in which the level of stress generated by the uncertainty varies with marital quality and with other personal and family resources, such as potency and an appreciation of the spouse's ability to cope with the stress. Four ways of coping with the uncertainty were observed in in-depth interviews: fighting, ignoring, postponing, and planning. The results are discussed in terms of their meaning for possible systemic interventions.

Adaptation, Psychological↗
PubMed1999

Lymphoepithelioma-like carcinoma of the colon in a patient with hereditary nonpolyposis colorectal cancer.

Tumors with features similar to those of nasopharyngeal carcinoma, so-called lymphoepithelioma-like carcinomas, have been described in several organs but are extremely rare in the colon. We describe a patient with a family history consistent with hereditary nonpolyposis colorectal cancer who had 3 malignant lesions in the right colon, namely, a mucinous cancer, a lymphoepithelioma-like carcinoma, and a well-differentiated adenocarcinoma with prominent lymphoid stroma. To the best of our knowledge, lymphoepithelioma-like carcinoma has not been described previously in hereditary nonpolyposis colorectal cancer.

Adenocarcinoma↗
PubMed1998

Is laparoscopic radical nephrectomy with specimen morcellation acceptable cancer surgery?

Laparoscopic radical nephrectomy (LRN) for renal-cell carcinoma (RCF) with removal of the specimen by morcellation and suction remains controversial because precise pathologic tumor staging is lost, and there is a risk of tumor seeding. We assessed the theoretical impact of surrendering precise pathologic staging on the management of patients with low-stage RCC (T3a or less). In 22 patients who underwent open radical nephrectomy for RCC, the preoperative CT-based clinical stage was correlated with pathologic tumor staging. Possible clinical inclusion criteria for LRN were then correlated with pathologic tumor staging. When comparing clinical and pathologic staging, one patient was understaged and seven were overstaged by preoperative CT. However, if clinical stage T3a or lower was used as the inclusion criterion for LRN, 19 patients (86%) would have been so treated, none would have been underassigned, and future management would not have been compromised according to pathologic staging. Management of patients with low-stage RCC relying on clinical staging only is oncologically adequate. This would make LRN an acceptable option for this subset of patients.

Carcinoma, Renal Cell↗
PubMed1998

Peritumoral and nodal muciphages.

Three patients who underwent surgery for cancer showed Alcian blue positive cells in the sinusoids of the regional lymph nodes and, in one case, extensive infiltration in the soft tissues around the tumor. The cells contained variably sized vacuoles that occasionally indented the nuclei, imparting a signet-ringlike appearance. They were interpreted as muciphages based on morphology, reactivity with mucin stains, positive immunohistochemical staining for KP-1 and Mac-387, and negative staining for cytokeratin, S-100, and leukocyte common antigen (LCA). The material contained in these cells was Alcian blue positive at pH 2.5 and pH 1, and was strongly periodic acid-Schiff positive after diastase digestion. Hyaluronidase only slightly reduced the intensity of the Alcian blue stain. These results indicate that the bulk of the material was epithelial-type mucin. To our knowledge, this is the first report of muciphages in lymph nodes. Careful attention to morphology and immunohistochemical findings is necessary to avoid confusion with metastatic or infiltrating signet ring or mucinous adenocarcinoma.

Adenocarcinoma↗
PubMed1995

Establishment of a colonic polyp registry in Rhode Island.

A colonic adenomatous polyp registry (PR) has been organized at the Roger Williams Medical Center whose main functions are to prevent the occurrence of colorectal cancer (CRC) in the enrollees, to provide a population of subjects for epidemiological and interventional studies, and to provide educational, including dietary, information to subjects and physicians. One hundred four and 202 patients with polyps, originally retrieved from the hospital pathology files, were enrolled in the 1984 and 1987 cohorts, respectively, of whom about 90% were followed for at least three years after polypectomy. Three carcinomas, all Dukes A, were found in the right colon in the follow-up period. New polyps identified in the first three years after polypectomy were generally small tubular adenomas with a greater predilection for the right colon than was found for the index polyps. Risk factors for new polyps included history of previous polyps and, probably, multiple index polyps. The use of colonoscopy for postpolypectomy surveillance increased between 1984 and 1987. About 25% of the subjects in each cohort were either lost to follow-up or received no endoscopic surveillance. On the other hand, some of those who were followed were probably subjected to excessive numbers of procedures. Defects in the PR include inadequacy of personal and family history data, and steady loss of patients during the three to six years after polypectomy. Despite the small size and limited resources of our hospital, its colonic polyp registry has already provided information that may help in the management of patients with this premalignant condition. The more widespread use of securely funded polyp registries would probably reduce the incidence of metachronous CRC in that population and would have significant epidemiological and educational functions.

Adenomatous Polyps↗
PubMed1995

Endoscopically removed malignant colorectal polyps: clinicopathologic correlations.

BACKGROUND/AIMS: Treatment options for patients with endoscopically removed malignant colorectal polyps are polypectomy alone vs. polypectomy followed by surgery. The aim of this study was to define histopathologic parameters that can be used for clinically relevant treatment decisions. METHODS: Five pathologists evaluated 140 polyps for the presence or absence of unfavorable histology. Unfavorable histology was tumor at or near (< or = 1.0 mm) the margin and/or grade III and/or lymphatic and/or venous invasion. Adverse outcome was recurrent and/or local cancer and/or lymph node metastasis. RESULTS: Adverse outcome was 19.7% (14 of 71), 8.6% (2 of 23), and 0% (0 of 46) when unfavorable histology was present, indefinite (lack of agreement), and absent, respectively (P < 0.0005, present vs. absent). Four patients with cancer > 1.0 mm from the margin had an adverse outcome (2 with lymphatic invasion and 2 indefinite for lymphatic invasion). Four patients with negative resections later developed distant metastases. Eight patients (6.3%) died of disease, and 2 of 69 without unfavorable histology (both indefinite for lymphatic invasion) had an adverse outcome. Interobserver strength of agreement was substantial to almost perfect for margin, grade, and venous invasion and fair to substantial for lymphatic invasion. CONCLUSIONS: This system is usable clinically. Patients with unfavorable histology are probably best managed by resection postpolypectomy, whereas in the absence of unfavorable histology, they probably can be treated by polypectomy only.

Colonic Polyps↗