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Thomas JS, Graff BM, Hollingsworth AO, Cohen SM, Rubin MM. Home visiting for a posthysterectomy population. HOME HEALTHCARE NURSE 1992; 10:47-52. [PMID: 1607287 DOI: 10.1097/00004045-199205000-00007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
There are many valid indications for providing home visits to posthysterectomy clients. In-home assessment of the client's status permits immediate care or referrals and saves unnecessary acute care visits to emergency rooms and physicians' offices. Nursing interventions have identified holistic healthcare needs and prevented other problems from developing. Assisting the clients in developing their problem-solving abilities enhances the goal of return to self-care during the immediate postoperative follow-up and afterward. Finally, the vital role the clinical nurse specialists can play in the healthcare system is more clearly established for these consumers of care.
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252
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Cohen SM. Chemotherapy of metastatic melanoma. THE MOUNT SINAI JOURNAL OF MEDICINE, NEW YORK 1992; 59:220-3. [PMID: 1351249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
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253
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Okamura T, Garland EM, Johnson LS, Cano M, Johansson SL, Cohen SM. Acute urinary tract toxicity of tetraethylorthosilicate in rats. FUNDAMENTAL AND APPLIED TOXICOLOGY : OFFICIAL JOURNAL OF THE SOCIETY OF TOXICOLOGY 1992; 18:425-41. [PMID: 1597267 DOI: 10.1016/0272-0590(92)90141-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Acute stomach, kidney, and bladder toxicity was evaluated in F344 rats after gastric gavage of tetraethylorthosilicate (TES) at daily doses of 0, 0.111, 0.223, and 0.333 g. Five rats of each sex at each dose were sacrificed after 1, 2, and 4 days. In TES-treated groups, silicate accumulated in the stomach glands and the muscle layer of the forestomach and glandular stomach. Serum chemistries demonstrated acute onset of renal failure. In the kidneys, acute tubular necrosis, accumulation of silicates, and superficial necrotizing papillitis were observed. In the renal pelvis and bladder, there was urothelial simple hyperplasia, focal erosion of the mucosa, edema, and inflammation. These acute toxic changes were dose and time dependent, but significant sex differences were not observed. The microscopic changes in the urothelium were similar to those observed following administration of high doses of sodium saccharin to male rats in which urinary silicate precipitate and crystals form.
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254
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Abstract
A discrete-time simulation model of carcinogenesis is described mathematically using recursive relationships between time-varying model variables. The dynamics of cellular behavior is represented within a biological framework that encompasses two irreversible and heritable genetic changes. Empirical data and biological supposition dealing with both control and experimental animal groups are used together to establish values for model input variables. The estimation of these variables is integral to the simulation process as described in step-by-step detail. Hepatocarcinogenesis in male F344 rats provides the basis for seven modeling scenarios which illustrate the complexity of relationships among cell proliferation, genotoxicity, and tumor risk.
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255
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Cohen SM, Sousa FJ, Kelly NE, Wendel RT. Respiratory arrest and new retinal hemorrhages after retrobulbar anesthesia. Am J Ophthalmol 1992; 113:209-11. [PMID: 1550194 DOI: 10.1016/s0002-9394(14)71540-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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256
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Karukstis KK, Moision RM, Johansen SK, Birkeland KE, Cohen SM. Alternative measures of photosystem II electron transfer inhibition in anthraquinone-treated chloroplasts. Photochem Photobiol 1992; 55:125-32. [PMID: 1603842 DOI: 10.1111/j.1751-1097.1992.tb04218.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have previously used chlorophyll fluorescence measurements at Fmax conditions (i.e. with Photosystem II electron acceptor QA reduced) to monitor the action of 9,10-anthraquinones on photosynthetic electron transport in plant chloroplasts. The present investigation employs two additional techniques to characterize the extent of electron transport inhibition induced by the addition of substituted anthraquinones to the suspending medium of spinach chloroplasts. Results are presented for spectrophotometric assays of the rate of electron transfer to an exogenous electron acceptor, 2,6-dichloroindophenol (DCIP) and for electrochemical determinations of the rate of oxygen evolution in anthraquinone-treated chloroplasts. In general, amino-substituted anthraquinones are ineffective inhibitors, maintaining electron transfer rates to DCIP at levels ranging from 50 to 90% of normal rates and yielding rates of O2 evolution averaging at 70% of the rate in untreated chloroplasts. In contrast, hydroxy-substituted anthraquinones efficiently block Photosystem II electron transport, resulting in low rates of DCIP photoreduction ranging from 0 to 20% of normal values and reducing O2 evolution rates to an average of 30% of the rate observed for untreated chloroplasts. Relative rates of DCIP photoreduction for anthraquinone-treated chloroplasts show a strong linear correlation with the reported relative Fmax chlorophyll fluorescence intensities. Relative O2 evolution rates are observed to correlate with the Stern-Volmer fluorescence quenching parameter Ksv. We suggest that slight differences in the extent of inhibitory activity of an anthraquinone as measured by the three techniques are consistent with certain known Photosystem II heterogeneities. The similarities in relative rankings of inhibitory effects for the 9, 10-anthraquinones, however, demonstrate that the three techniques employed (measurements of Fmax chlorophyll fluorescence, DCIP photoreduction rates, and O2 evolution rates) are alternative assays of anthraquinone-induced Photosystem II electron transport inhibition.
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257
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Cohen SM, Laurito CE, Curran MJ. Grand mal seizure in a postpartum patient following intravenous infusion of caffeine sodium benzoate to treat persistent headache. J Clin Anesth 1992; 4:48-51. [PMID: 1540370 DOI: 10.1016/0952-8180(92)90121-g] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A 27-year-old parturient developed a severe headache after placement of a labor epidural catheter. A presumptive diagnosis of an occult postdural puncture headache (PDPH) was made, and the patient was treated with an intravenous (IV) infusion of 500 mg of caffeine sodium benzoate (CSB) to vasoconstrict dilated cerebral vessels. Shortly after the infusion was completed, the patient experienced a self-limited grand mal seizure, which recurred later during her hospitalization. Despite a neurologic consultation and extensive testing, no definitive cause for the seizure was found. In light of the temporal relationship between caffeine use and the development of seizure activity, reports implicating caffeine's contribution to seizure activity, and evidence of a prolongation of the substance's half-life during and after pregnancy, we urge caution in the use of this drug in parturients.
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258
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Graff BM, Thomas JS, Hollingsworth AO, Cohen SM, Rubin MM. Development of a postoperative self-assessment form. CLIN NURSE SPEC 1992; 6:47-50. [PMID: 1559211 DOI: 10.1097/00002800-199200610-00013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
This paper describes a patient self-assessment form developed for use in a research study examining early discharge and transitional nursing follow-up care for women with abdominal hysterectomy. Transitional care nursing involves preparation for an early discharge from the hospital and nursing follow-up for convalescence at home through an 8-week recovery period. The goal of transitional care is to assist the client in regaining her preoperative level of self-care. This article will include a brief overview of the ongoing research study, a description of the role of the clinical nurse specialist (CNS) in transitional care, and the use of the self-assessment form. The form is applicable to numerous clinical settings.
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259
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Cohen SM, Ellwein LB. Genetic errors, cell proliferation, and carcinogenesis. Cancer Res 1991; 51:6493-505. [PMID: 1742722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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260
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Cohen SM. Carcinogenicity of antioxidants. Jpn J Cancer Res 1991; 82:1454-5. [PMID: 1778771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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261
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Cohen SM, Kurtz AB. Biliary sonography. Radiol Clin North Am 1991; 29:1171-98. [PMID: 1947040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Ultrasonography is a dynamic, powerful, and readily available tool in the armamentarium of biliary diagnosis. The use of this modality is indicated in the initial work-up of jaundice since ultrasonography is exquisitely sensitive to the presence of intrahepatic or extrahepatic biliary dilatation. The liver and pancreas may be screened for focal masses. In acute right upper quadrant pain, ultrasonography can assess the organs residing in this area, often yielding significant information in the diagnosis of gallbladder disease. Newer modalities such as color Doppler may add specificity and reliability to sonographic findings.
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262
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Garland EM, Shapiro R, Kraft PL, Mattson BJ, Parr JM, Cohen SM. Effects of in utero and postnatal sodium saccharin exposure on the nutritional status of the young rat. II. Dose response and reversibility. Food Chem Toxicol 1991; 29:669-79. [PMID: 1959820 DOI: 10.1016/0278-6915(91)90124-p] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A previous study in our laboratory demonstrated that 30-day-old Sprague-Dawley rats exposed to 7.5% sodium saccharin (NaS) since conception differ from untreated rats in several physiological parameters. In the present study, to determine the dose response of the changes associated with NaS treatment, animals were evaluated at 30 days post-birth, after treatment with dietary levels of 0, 1, 3 or 7.5% NaS since conception. Most physiological consequences of NaS treatment in the weanling rat, including anaemia and reductions in serum folate and vitamin A concentrations, were dose dependent. Serum vitamin E, cholesterol and triglyceride concentrations were decreased at the two lower doses of NaS but were significantly increased with 7.5% NaS. The no-effect level (NOEL) was similar for physiological effects and for bladder tumour production in two-generation studies (1% NaS in the diet). The reversibility of the effects of 7.5% NaS was examined in 90-day-old rats. The increases in lipids and vitamin E were reversible. Although values for haematological parameters and serum vitamin A remained significantly reduced at 90 days, changes were less severe than at 30 days. Histological examinations revealed that the effects of 7.5% dietary NaS on the bladder were negligible, indicating that the physiological changes observed in the young rat are probably not directly related to the production of bladder tumours.
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263
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Masui T, Mann AM, Macatee TL, Garland EM, Okamura T, Smith RA, Cohen SM. Direct DNA sequencing of the rat neu oncogene transmembrane domain reveals no mutation in urinary bladder carcinomas induced by N-butyl-N-(4-hydroxybutyl)nitrosamine, N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide or N-methyl-N-nitrosourea. Carcinogenesis 1991; 12:1975-8. [PMID: 1682063 DOI: 10.1093/carcin/12.10.1975] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Epidermal growth factor (EGF) and EGF-related growth factors are present in the urine, and EGF has been identified as a urinary component that enhances urinary bladder tumor formation in rats. Neu oncogene encodes a cell surface receptor similar to the EGF receptor and is known to be activated by a point mutation of DNA that encodes the transmembrane domain of the neu protein (p185). In this study, we examined the possible mutational activation of neu oncogene in 50 urinary bladder transitional cell carcinomas (TCC) induced in F344 rats by the following carcinogenesis models: (i) 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) (4 weeks)----3% uracil (20 weeks); (ii) 0.2% N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) (6 weeks)----5% sodium saccharin (72 weeks); and (iii) N-methyl-N-nitrosourea (MNU) 20 mg/kg body wt, i.p. twice per week for 4 weeks----3% uracil (20 weeks). The DNA sequence around the transmembrane domain of neu gene was amplified by PCR and sequenced. The results showed no mutation within the examined DNA sequences, indicating that neu oncogene is not activated by a point mutation in the transmembrane domain in urinary bladder carcinomas induced by BBN, FANFT or MNU.
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264
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Garland EM, Kraft PL, Shapiro R, Khachab M, Patil K, Ellwein LB, Cohen SM. Effects of in utero and postnatal sodium saccharin exposure on the nutritional status of the young rat. I. Effects at 30 days post-birth. Food Chem Toxicol 1991; 29:657-67. [PMID: 1959819 DOI: 10.1016/0278-6915(91)90123-o] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The incidence of sodium saccharin (NaS)-associated bladder tumours in male rats increases when exposure to high doses begins in utero or at birth compared with treatment after weaning. The present experiment evaluated the effect of NaS exposure on selected physiological parameters in young second generation rats. 6-wk-old male and female Sprague-Dawley rats were placed on either a diet supplemented with 7.5% NaS or an untreated diet, and mated 4-6 wk later. Treatment was continued through lactation and the offspring were weaned on to the same diet. Body weights were significantly depressed in NaS-treated litters by 4 days after birth, and were 35% lower than controls by 30 days when the animals were killed. NaS treatment of the offspring was associated with an increase in faecal moisture content and caecal content weight, changes in several urinary analytes, a 50% increase in serum cholesterol a 10-fold increase in serum triglycerides and decreases in serum and hepatic vitamins. In addition, NaS-treated dams and pups were anaemic. Relatively few differences between males and females were noted, but significant inter-litter differences existed. The numerous physiological changes indicate that 7.5% dietary NaS exceeds the maximum tolerated dose for weanling rats.
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265
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Cohen SM, Cano M, Earl RA, Carson SD, Garland EM. A proposed role for silicates and protein in the proliferative effects of saccharin on the male rat urothelium. Carcinogenesis 1991; 12:1551-5. [PMID: 1893514 DOI: 10.1093/carcin/12.9.1551] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
High doses of sodium saccharin, a non-genotoxic chemical, lead to the formation of silicate-containing precipitate and microcrystals in urine of male rats. Differences in urinary protein, pH, sodium and other factors affect silicate-containing precipitate and microcrystal formation as well as the bladder effects of sodium saccharin. Total urinary silicon concentration (mostly soluble) in sodium saccharin-fed rats is similar to or lower than the concentration in control rats. Binding of saccharin to male rat urinary proteins was demonstrated by equilibrium-gel filtration. We propose that by binding to urinary proteins under appropriate conditions, saccharin produces a nidus for the formation of silicate-containing precipitate and crystals. These appear to be cytotoxic to the superficial bladder epithelium, with cell death resulting in regenerative hyperplasia. Factors that influence the formation of these silicate-containing materials might provide a rationale for sex, species, dose and dietary differences in response to sodium saccharin.
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266
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Cohen SM, Taber KH, Malatesta PF, Shpungin J, Berman C, Carlin JR, Werrmann JG, Prahalada S, Bryan RN, Cordes EH. Magnetic resonance imaging of the efficacy of specific inhibition of 5 alpha-reductase in canine spontaneous benign prostatic hyperplasia. Magn Reson Med 1991; 21:55-70. [PMID: 1719333 DOI: 10.1002/mrm.1910210109] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A leading role for prostatic levels of dihydrotestosterone (DHT) in the pathogenesis of benign prostatic hyperplasia is well established, if incompletely understood. The present study provides initial confirmation that 5 alpha-reductase inhibition alone is sufficient to prevent prostatic accumulation of DHT and to produce epithelial regression in the canine prostate. In dogs treated with the specific 5 alpha-reductase inhibitor finasteride, prostatic volume decreased to one-third of the baseline volume, while the prostatic concentration of DHT fell fivefold: both were constant in placebo control dogs. Demonstration that MR imaging can serve as accurate modality to assess prostatic volume was provided by serial measurements of the canine prostate and by correlation of the last imaging measurement with the weight of the excised prostate. Significant intensity changes were observed in T2-weighted images measured post-treatment; these changes correlated with the histopathology of the prostate. These results suggest that beyond quantifying regression, multiecho T2 measurements can be useful in probing accompanying changes occurring on the cellular level.
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267
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Abstract
Painful diabetic distal sensory neuropathy is a disabling and common complication of diabetes mellitus. There is evidence that microvascular changes resulting in ischemia to the vasa nervorum may contribute to this problem. Pentoxifylline has been shown to improve circulation through partially occluded peripheral vessels and has been postulated to be of potential benefit. Forty adult type II diabetics were enrolled in a double-blind, placebo-controlled study utilizing pentoxifylline for six months. Visual analog scores, nerve conduction studies, and physical examinations were used to evaluate response to treatment. At the end of the six-month trial, there was no significant difference in the patients' pain between the pentoxifylline- and placebo-treated groups. The authors conclude that pentoxifylline is not useful in the treatment of painful distal diabetic neuropathy.
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268
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Masui T, Ward JM, Cohen SM. Enhanced immunoreactivity of ras oncogene p21 protein in urinary bladder epithelium of rats treated with N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide. Cancer Lett 1991; 59:95-102. [PMID: 1884376 DOI: 10.1016/0304-3835(91)90172-e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Normal urothelium and various lesions of the rat urinary bladder induced by the dietary administration of 0.2% N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT) (up to 77 weeks) or by the combination of 0.2% FANFT and the subsequent administration of 5% sodium saccharin or 2% DL-tryptophan (up to 104 weeks) were evaluated for immunoreactivity with monoclonal antibody to ras p21 by avidin-biotin immunohistochemistry. Seventy-one to 100% of transitional cell carcinomas showed strong reactivity to the antibody to ras p21 depending on treatment with long-term administration of FANFT or by 6 weeks administration of FANFT followed by sodium saccharin or DL-tryptophan. Focal reactivity to the ras p21 antibody was frequently observed in the hyperplastic (57-96%) or normal appearing urinary bladder epithelium (50-100%) in rats treated with FANFT (FANFT alone or in combination with sodium saccharin or tryptophan) but not in hyperplasia or normal epithelium in rats given sodium saccharin or tryptophan alone, without pretreatment with FANFT or in untreated controls. The present results show that there is a close association of enhanced immunoreactivity with ras p21 antibody in the urinary bladder epithelium to FANFT treatment, and that ras p21 is expressed in normal, hyperplastic and neoplastic lesions of the bladder of rats treated with FANFT. These results suggest that enhanced immunoreactivity with ras p21 is observed as a consequence of the treatment with FANFT but it alone does not reflect the progression from benign to malignant lesions.
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269
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Diettrich NA, Cacioppo JC, Kaplan G, Cohen SM. A growing spectrum of surgical disease in patients with human immunodeficiency virus/acquired immunodeficiency syndrome. Experience with 120 major cases. ARCHIVES OF SURGERY (CHICAGO, ILL. : 1960) 1991; 126:860-5; discussion 865-6. [PMID: 1854246 DOI: 10.1001/archsurg.1991.01410310070010] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
One hundred twenty major general surgical procedures were performed on 88 adult patients harboring the human immunodeficiency virus. Fifty-eight (48%) of the procedures were performed on patients who fulfilled the criteria for acquired immunodeficiency syndrome. The patients were predominantly male (94%). Single risk factors included homosexuality (73% of cases), intravenous drug abuse (8%), and previous blood transfusions (8%). Four patients (5%) had multiple risk factors; risk factors were denied by seven patients (8%). The mean age at surgery was 41.6 years (range, 22 to 67 years). Surgical conditions that rarely affect the population without the human immunodeficiency virus presented diagnostic challenges. Altered physiologic responses to even routine conditions were observed. Thirty-day morbidity rates for emergency (group A) and elective (group B) procedures were 19% and 9%, respectively. This included seven surgical deaths (13%) in group A and one in group B (2%). Patients undergoing 92 of 112 procedures (82%) not associated with surgical mortality were followed up. Patients who were dead at follow-up had mean procedure-survivals of 19 weeks (group A) and 21 weeks (group B) for 33 procedures. Those who remained alive had a mean procedure-survival of 86 weeks for 59 procedures. No single prognosticator could be correlated with outcome, although the combination of hypoalbuminemia with a history of opportunistic infection(s) was associated with short survival. Emergency and elective procedures can be performed in the patient with human immunodeficiency virus/acquired immunodeficiency syndrome with acceptable morbidity and mortality. Procedures are indicated to extend patient life or to improve quality of life.
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270
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Masui T, Mann AM, Macatee TL, Okamura T, Garland EM, Fujii H, Pelling JC, Cohen SM. H-ras mutations in rat urinary bladder carcinomas induced by N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide and sodium saccharin, sodium ascorbate, or related salts. Cancer Res 1991; 51:3471-5. [PMID: 2054786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Male F344 rats were fed 0.2% N-[4-(5-nitro-2-furyl)-2-thiazoly]formamide for 6 weeks and then fed 3% or 5% sodium saccharin, 5% sodium ascorbate, 3.12% calcium saccharin, 1.34% sodium chloride, 5.2% calcium saccharin plus 1.34% sodium chloride, or basal diet alone for 72 weeks. Protein and DNA were extracted from 89 bladder tumors [87 transitional cell carcinomas (TCC), 1 papilloma, and 1 sarcoma] from 86 rats p21 expression was examined by Western blotting using a monoclonal antibody against p21 (NCC-RAS-004). H-ras mutations in exons 1 and 2 were examined by direct sequencing of DNA amplified by polymerase chain reaction. Sequencing results demonstrated mutations at codon 61 (CAA to CGA in 15 TCCs; CAA to CTA in 2 TCCs), at codon 12 (GGA to TGG in 1 TCC), and at codon 13 (GGC to GTC in 3 TCCs). Mutations at codon 61 were confirmed by faster mobility of the p21 band in Western blots. The level of p21 expression varied among samples, but many TCCs appeared to express more p21 than controls. The overall incidence of H-ras mutations was 24.4% (21 of 86 rats). The type of chemical used for the promoting phase had essentially no effect on H-ras mutation, suggesting that the effects observed were related to FANFT administration. The frequency of H-ras mutation in each group was negatively related to the incidence of carcinoma (r = -0.85; P less than 0.01). Two groups of tumors (with or without the mutated ras gene) were compared for tumor size (reflected by the bladder weight), histological grading, and the presence of invasion. The size of tumors with mutated ras was significantly smaller than those without mutated ras. There was no difference in the histological grading between the two groups. Although not statistically significant, histological invasion was more frequently observed in tumors with mutated ras (14.3%) than in tumors without mutation (3.1%).
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271
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Cohen SM. Difference in rates of response to chemotherapeutic agents between men and women with malignant melanoma. J Natl Cancer Inst 1991; 83:880. [PMID: 1953860 DOI: 10.1093/jnci/83.12.880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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272
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Abstract
Feeding of high levels of uracil to laboratory rodents results in the formation of calculi in the lumen of the urinary bladder. This urolithiasis stimulates cellular proliferation in the bladder and has been used in studies of two-stage carcinogenesis. Quantitation of uracil in rodent diet was achieved by extraction from the diet with ammonium hydroxide. The extract was applied to a strong anion-exchange solid-phase extraction column. Uracil is not retained on this matrix which adsorbs the majority of contaminants in the extract. The uracil was quantitated by HPLC on an ODS microbore column (100 x 2 mm internal diameter) eluted at 0.5 ml/min with 200 mM KH2PO4, pH 3.5, at 30 degrees C. Three structurally related pyrimidine bases, cytosine, uracil, and thymine, showed increasing retention on this column/solvent combination, thereby demonstrating selectivity of the analysis. Recovery of uracil was 76-90% with lower values observed when dietary levels of uracil were in excess of 4.5%.
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273
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Cohen SM, Vaidyanathan J, Haeberle RC. Direct post and core pattern made with light-curing composite resin. J Prosthet Dent 1991; 65:854-6. [PMID: 1830101 DOI: 10.1016/s0022-3913(05)80027-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
An unfilled Bis-GMA composite resin can be used advantageously for making an accurate cast post and core pattern. The technique is faster and easier than normal pattern fabrication methods using an unfilled acrylic resin, wax, or a combination of the two.
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274
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Cohen SM, Eliyahu D, Freund I, Kaveh M. Vector statistics of multiply scattered waves in random systems. PHYSICAL REVIEW A 1991; 43:5748-5751. [PMID: 9904899 DOI: 10.1103/physreva.43.5748] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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275
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McDermott IG, Cohen SM. An alginate pick-up alternative to the altered cast technique. COMPENDIUM (NEWTOWN, PA.) 1991; 12:310, 312, 314-5. [PMID: 1933981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The altered cast technique for distal extension removable partial dentures involves such cumbersome laboratory procedures that many dentists avoid using it. This article presents a simple and easy clinical technique that accomplishes the same objective, but involves no additional laboratory work. In addition, the technique provides superior accuracy when compared with the altered cast technique.
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