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M B Cohen

Publications and source records attributed to M B Cohen.

At least 163 records · Page 9Linked to original sources
PubMed1993

The palpable breast nodule. A cost-effectiveness analysis of alternate diagnostic approaches.

BACKGROUND: Traditionally, open biopsy has been considered the optimal procedure for the diagnosis of breast nodules. Fine-needle aspiration biopsy (FNAB) has been proposed as an alternate method for the diagnosis of many palpable breast lesions. METHODS: The authors compared the diagnostic utility of open biopsy and FNAB using decision tree and cost-effectiveness analyses. RESULTS: When compared with two-step excisional biopsy, FNAB achieved a savings of over $700 at the cost of 0.1% decrease in 10-year overall survival. CONCLUSIONS: These data indicate FNAB to be a reasonable alternative to open biopsy for the diagnosis of palpable breast lesions in many patients.

Adult↗
PubMed1993

Alpha-fetoprotein half-life as a predictor of residual testicular tumor. Effect of the analytic strategy on test sensitivity and specificity.

BACKGROUND: Alpha-fetoprotein (AFP) serum values after orchiectomy for testicular cancer can be used to predict the residual disease status. However, the optimal strategy for postorchiectomy marker analysis has not been studied. This article evaluated different analytic methods in an effort to identify the approach that provided the greatest sensitivity and specificity for occult residual disease. METHODS: Statistical information on the AFP half-life (t1/2) derived from a clinical data set of 24 patients with AFP-secreting clinical Stage A testicular cancer and pathologically defined nodal status was incorporated into a mathematic model of postorchiectomy marker values as a function of residual tumor volume and time. The model was used to test the effect of various analytic strategies on detecting the residual tumor. The clinical data set then was analyzed to measure the effect of different analytic methods on the predictive value of the AFP t1/2. RESULTS: In the model, the AFP t1/2 calculated from a single set of serum measurements obtained from the initial serum t1/2 was a poor predictor of disease status in patients with up to 40% residual tumor volume. Determined by the sequential addition of serum values obtained at normal t1/2 intervals, the AFP t1/2 improved in sensitivity but required up to seven serial values (35 days) to detect an abnormal t1/2 in patients with 10% residual tumor. By contrast, changes in the most recent interval t1/2 relative to the initial calculated t1/2 predicted the disease status in patients with 10% residual tumor after four t1/2 (20 days) and in patients with 1% residual volume after 35 days. CONCLUSIONS: The use of this last strategy in the clinical data set improved both the sensitivity and specificity of the AFP t1/2 in predicting residual tumor relative to the other methods.

Half-Life↗
PubMed1993

Fine-needle aspiration biopsy of subcutaneous fat necrosis of the newborn.

This report provides the first description of the fine-needle aspiration biopsy findings in a case of subcutaneous fat necrosis of the newborn. While initial interpretation of the aspirate smears was suspicious for a neoplastic process, subsequent incisional biopsy confirmed the benign nature of the lesion. Review of the cytologic material revealed rare, negatively stained, needle-shaped crystals within histiocytes and multinucleate giant cells. In the appropriate clinical setting, and given a mixture of lymphocytes, histiocytes, and multinucleate giant cells in the aspirate smears, we believe the finding of negatively stained needle-shaped crystals can strongly suggest the diagnosis of subcutaneous fat necrosis of the newborn.

Adipose Tissue↗
PubMed1993

Receptors for Escherichia coli heat stable enterotoxin in human intestine and in a human intestinal cell line (Caco-2).

Escherichia coli heat stable enterotoxin (STa) and the newly identified endogenous ligand guanylin bind to an intestinal receptor and activate membrane bound guanylate cyclase. We compared STa binding and affinity crosslinking of STa receptors in human small intestine to those in the Caco-2 human colon carcinoma cell line. STa had similar kinetics of binding in human intestinal and Caco-2 brush border membranes. In both human intestine and Caco-2 brush border membranes, multiple specifically radiolabeled bands, including a 140-165 kDa band, were identified by affinity crosslinking. However, in human intestine the most prominent autoradiographic species was a 60 kDa band. A 60 kDa protein was also specifically immunoprecipitated from solubilized human brush border membranes using antisera raised against a cloned STa receptor fusion protein. Our observations of multiple crosslinked proteins in human intestine and Caco-2 cells could be explained by the existence of several members of a family of STa receptors and/or the existence of smaller STa binding proteins generated by the protease cleavage of a larger complete STa receptor.

Bacterial Toxins↗
PubMed1993

Comparison of five histopathologic methods to assess cellular proliferation in transitional cell carcinoma of the urinary bladder.

Transitional cell carcinomas of the urinary bladder vary in their biologic potential, which may be correlated with the grade and stage of the tumor. Cellular proliferation may prove to be another measure of predicting tumor biologic potential. We have compared five different methods to assess proliferation in 26 tumors and correlated these results with tumor grade and stage. A portion of each tumor was incubated in vitro with bromodeoxyuridine (BrdUrd). For each tumor this was compared with at least three of the following four other markers of proliferation: mitotic count, silver-stained nucleolar organizer regions, immunohistochemical staining with Ki67, and proliferating cell nuclear antigen. Statistical correlations were seen between tumor grade and stage and these markers. There were strong correlations between the BrdUrd labeling index (LI) and both the Ki67 LI and proliferating cell nuclear antigen LI. The correlation between the BrdUrd LI and mitotic count was more tenuous; no significant correlation was found between BrdUrd LI and silver-stained nucleolar organizer region count. The correlation between these measurements of proliferation and tumor grade and stage was less strong. Our data suggest that cellular proliferation of transitional cell carcinomas can be reliably assessed with several different markers and that most of these markers can be correlated with tumor grade but not with stage.

Bromodeoxyuridine↗
PubMed1993

Cell proliferation in prostatic adenocarcinoma: in vitro measurement by 5-bromodeoxyuridine incorporation and proliferating cell nuclear antigen expression.

We assessed cancer cell proliferation, a marker of the biologic activity of tumor cells, by evaluating bromodeoxyuridine (BrdUrd) incorporation and proliferating cell nuclear antigen (PCNA) expression. Prostatic carcinoma specimens (N = 48) were incubated in the presence of BrdUrd to label cells undergoing DNA synthesis, and immunocytochemical staining was performed with monoclonal antibodies to BrdUrd and PCNA and a standard indirect immunoperoxidase technique. The proportion of cells staining positively (labeling index or LI) for BrdUrd and PCNA was determined in 2 ways: by counting only high-power fields with the greatest concentration of stained cells (selected LI); or by counting cells in random fields (random LI). For BrdUrd the mean selected and random LIs were 3.08% and 1.62%, respectively; for PCNA they were 6.02% and 3.47%. Random and selected BrdUrd correlated well (r2 = 0.83), as did random and selected PCNA LIs (r2 = 0.86). However, a weaker correlation was noted when LIs of both techniques were compared, with the PCNA LI usually higher. The LIs of either technique correlated rather poorly with tumor grade and concentration of prostate-specific antigen, but correlated well with clinical stage as assessed by examination and imaging. In addition, either technique discriminated among tumors known to be pathologically confined (stages A and B) and those with extension to seminal vesicles (stage C) or metastatic to regional lymph nodes or bone (p < 0.019).

Adenocarcinoma↗
PubMed1993

Inverted V peritoneotomy significantly improves nodal yield in laparoscopic pelvic lymphadenectomy.

We compared the nodal yield and volume of target tissue removed in 3 groups of patients undergoing laparoscopic pelvic lymphadenectomy as a staging procedure for carcinoma of the prostate. With the exception of the type of peritoneotomy used to expose the obturator fossa, surgical management of all patients was identical. Results were evaluated in patients undergoing linear peritoneotomy (40), inverted V peritoneotomy (14) or both procedures (28, 1 approach on each side). Significantly more tissue was removed from patients in the inverted V group (16.3 +/- 8.3 cm.3) compared to the linear peritoneotomy group (7.2 +/- 5.7 cm.3, p = 0.004). This resulted in a significant increase in nodal yield in patients in the inverted V group (11.0 +/- 4.1) relative to the linear peritoneotomy group (6.8 +/- 5.2, p = 0.003). In terms of the volume of tissue removed and the number of nodes obtained, combination patients had values intermediate to those in the other groups (11.6 +/- 10.5 cm.3 and 8.8 +/- 5.6 nodes, respectively). The right-to-left ratio of nodes and tissue volume was reversed in the combination group relative to the other 2 groups. Operative time was significantly decreased for the inverted V technique compared to the linear peritoneotomy approach (p = 0.01). No difference in operative blood loss of complications was identified. The improved exposure obtained with this technique appears to result in a more complete lymphadenectomy without increased risk of complications.

Humans↗
PubMed1993

Granulomatous inflammation in bladder wash specimens after intravesical bacillus Calmette-Guerin therapy for transitional cell carcinoma of the bladder.

The authors retrospectively reviewed a series of bladder wash cytologic specimens and concurrently available bladder biopsy samples to evaluate granulomatous inflammation in patients receiving intravesical bacillus Calmette-Guerin (BCG) immunotherapy for transitional cell carcinoma of the bladder. Comparisons were made during the 2-month period following six weekly BCG instillations in 25 patients and during the 1-year period following the last dose of BCG in 23 patients. At some point during the 2-month follow-up period, cytologic specimens contained free histiocytes in 64%, histiocyte aggregates (resembling fragments of granulomas) in 76%, and multinucleated histiocytic giant cells in 56% of patients. Similarly, concurrent biopsy samples contained granulomas in 78% and multinucleated giant cells in 56% of patients. During the 1-year period following the last dose of BCG, inflammatory changes peaked within the first 3 months and gradually resolved at 9-12 months. In none of these instances were the cytologic features of granulomatous inflammation misinterpreted as malignant. It was concluded that the cytologic findings after intravesical BCG are more specific than previously realized and closely parallel the histologic changes seen in corresponding bladder biopsy specimens.

Adult↗
PubMed1993

Gastrointestinal infection in children.

Infections of the gastrointestinal tract remain an important cause of childhood morbidity and mortality worldwide. A number of pertinent articles have appeared in the past year, advancing our understanding of 1) Helicobacter pylori-induced gastroduodenal disease, 2) Escherichia coli O157:H7-mediated diarrhea, and 3) newer gastrointestinal parasites that cause diarrhea. These are the topics of review.

AIDS-Related Opportunistic Infections↗
PubMed1993

Colonization by enteroaggregative Escherichia coli in travelers with and without diarrhea.

Enteroaggregative Escherichia coli (EAggEC) has been found to be associated with pediatric diarrhea in developing countries. In order to determine the role of EAggEC as an agent of traveler's diarrhea, we used a sensitive and specific DNA probe for EAggEC to screen bacterial colony blots from 278 volunteers before and after travel. Colonization with EAggEC was infrequent (2.5%) prior to travel but rose to 27 to 33% after travel in volunteers who took either placebo or trimethoprim-sulfamethoxazole. Travelers who took trimethoprimsulfamethoxazole were colonized with organisms that were uniformly resistant to that antimicrobial agent; when volunteers received ciprofloxacin, colonization with EAggEC was prevented (2.0%). Although colonization rates were high in the placebo and trimethoprim-sulfamethoxazole groups, only a minority of travelers who were colonized with EAggEC experienced diarrhea. On the basis of our data, we suggest that colonization with EAggEC alone is not sufficient to cause traveler's diarrhea.

Adult↗
PubMed1993

Comparison of receptors for Escherichia coli heat-stable enterotoxin: novel receptor present in IEC-6 cells.

Enterotoxigenic Escherichia coli elaborate a heat-stable enterotoxin that causes diarrhea in humans and animals. The primary event in the diarrheal cascade is the binding of this enterotoxin to specific receptors on enterocytes and activation of guanylyl cyclase. Two intestinal cell lines, Caco-2 and IEC-6, were tested for the presence of these receptors. Although both cell lines exhibited specific binding, only the Caco-2 cell line responded to heat-stable enterotoxin with increased guanylyl cyclase activity. Cloning and expression studies confirmed that the receptor present in Caco-2 cells is a homologue of guanylyl cyclase C, a known transmembrane heat-stable enterotoxin receptor. Expression of the receptor in differentiating Caco-2 cells increases with cell maturation, indicating that these cells are a suitable model for future studies. However, Northern and polymerase chain reaction analyses demonstrated that guanylyl cyclase C is not expressed in IEC-6 cells, strongly suggesting the presence of a novel heat-stable enterotoxin receptor that is not coupled to guanylyl cyclase activity.

Amino Acid Sequence↗
PubMed1993

Value of having a cytopathologist present during percutaneous fine-needle aspiration biopsy of lung: report of 55 cancer patients and metaanalysis of the literature.

OBJECTIVE: Percutaneous fine-needle aspiration biopsy is an accepted procedure for diagnosing intrathoracic malignant disease. The value of having a cytopathologist present during the procedure was studied with respect to the number of needle passes, the accuracy of the procedure, and complications. A metaanalysis was performed on the combined results of the present and previous series. SUBJECTS AND METHODS: We analyzed data from 55 adult patients who underwent percutaneous CT-guided fine-needle (22-gauge) aspiration biopsy of the lung for a lesion that either the biopsy or another subsequent invasive procedure showed to be nonlymphomatous and malignant. A cytopathologist was present for the first 25 procedures and not present for the next 30 procedures. When present, the cytopathologist stained the aspirated material with toluidine blue and gave an immediate opinion on the diagnostic adequacy of the specimen based on microscopic evaluation. If appropriate, the radiologist obtained additional biopsy specimens. When a cytopathologist was not present, the radiologist assessed the adequacy of the specimen by gross examination. A metaanalysis was performed of 211 cases from the present study and two previous series with respect to the effect of the presence of a cytopathologist on the diagnostic accuracy of the procedure. RESULTS: Biopsy specimens showed cancer in 25 (100%) of 25 patients when obtained while the cytopathologist was present, and in 24 (80%) of 30 patients when obtained while the cytopathologist was absent (p < .05, Fisher exact test). No significant differences in the number of needle passes performed or in the frequency of pneumothorax when aerated lung was traversed were noted between the two groups. Although two previous studies showed nonsignificant trends toward increased accuracy of thoracic fine-needle aspiration when a cytopathologist participated in the procedure, metaanalysis revealed significantly increased accuracy when a cytopathologist was present (p < .02, Mantel-Haenszel chi 2-test). CONCLUSION: An accurate diagnosis from fine-needle aspiration biopsy of intrathoracic cancer was more likely when a cytopathologist was present than when not present during the procedure.

Adult↗
PubMed1993

5-Bromodeoxyuridine incorporation and PCNA expression as measures of cell proliferation in transitional cell carcinoma of the urinary bladder.

Cell proliferation in 66 transitional cell carcinomas of the human urinary bladder was evaluated using immunohistochemical detection of in vitro 5-bromodeoxyuridine (BrdUrd) incorporation and of proliferating cell nuclear antigen (PCNA). The labeling index (LI) was defined as percent of labeled nuclei for 2000 tumor nuclei counted. The BrdUrd LI ranged from 0.2% to 38.9%, geometric mean = 8.4% (n = 61), and the PCNA LI ranged from 0.4% to 64.1%, geometric mean = 12.7% (n = 60). For the 55 tumors that were stained by both procedures, the BrdUrd LI showed a highly significant regression on the PCNA LI (BrdUrd LI = 0.74 * PCNA LI, R2 = 0.71, p < 0.0001, coefficient of variation of residual = 17.7%, log transformed data). When compared to clinical and histopathologic criteria, both labeling indices were substantially lower in low grade (Grade 1) versus high grade (Grades 2 and 3) tumors and in Ta tumors versus higher stage T1, T2, and T3 tumors. These studies show that BrdUrd incorporation can be used reliably to measure cell proliferation in fresh bladder tissue, that PCNA labeling is a similar measure of cell proliferation, and that both measures are low in tumors of low histopathologic grade and stage.

Aged↗
PubMed1993

Traveler's diarrhea.

Traveler's diarrhea is the most common health problem in persons who visit developing countries. Dietary precautions are the mainstay of prevention. Since bacteria are responsible for 50 to 80 percent of cases of traveler's diarrhea, antibiotics are the drugs of choice for empiric therapy. Because bacteria are becoming increasingly resistant to trimethoprim-sulfamethoxazole and doxycycline, newer antibiotics, especially the fluoroquinolones, should be considered as first-line therapy. Antimotility agents may help reduce symptoms, but they should not be given to patients who have fever or bloody diarrhea. Antibiotic prophylaxis is recommended for certain high-risk individuals.

Diarrhea↗
PubMed1993

Approach to the pediatric patient with diarrhea.

Numerous viral, bacterial, and parasitic pathogens are known to cause diarrheal illnesses with increased frequency in children. Oral rehydration can be used to treat and prevent dehydration, the major sequela of diarrhea in children. The impact of diarrhea on nutrition may also be reduced through the rapid restoration of a normal, age-appropriate diet. Most diarrheal illnesses are acute and self-limited; however, increased knowledge of persistent diarrheal syndromes in children may lead to prompt recognition and diagnosis in children with diarrhea lasting more than 2 weeks.

Anti-Infective Agents↗