PubMed Health⌕ Search

Biomedical subjects

R S Hoffman

Publications and source records attributed to R S Hoffman.

At least 73 records · Page 4Linked to original sources
PubMed1998

The effects of nutrition on plasma cholinesterase activity and cocaine toxicity in mice.

BACKGROUND: Low plasma cholinesterase activity is associated with severe cocaine toxicity in human subjects and animal experiments. Exogenously enhanced plasma cholinesterase activity is protective against cocaine toxicity in animals. Cocaine users tend to have lower plasma cholinesterase activity than controls. Yet, when cocaine users are allowed to use cocaine in controlled settings without dietary restriction, their plasma cholinesterase activity increases. This study evaluates the influence of diet on plasma cholinesterase activity and cocaine toxicity. METHODS: Forty-five Swiss albino mice were maintained on a high (30%) protein diet for 3 weeks. They were then randomized into equal groups and given either the high protein diet, an isocaloric low protein diet, or a protein and calorie deficient diet which consisted of reduced intake of the high protein diet. Body weights and plasma cholinesterase activities were measured after a 21-day study period. All animals then received a fixed dose of intraperitoneal cocaine and were observed for seizures and death. RESULTS: Body weights and plasma cholinesterase activities of the high protein animals remained stable. Weights for the low protein and reduced intake animals fell by 5% and 15%, respectively (p < 0.05 for both vs baseline). Similarly, plasma cholinesterase activities for the low protein and reduced intake animals fell by 4% and 10%, respectively (p = 0.06 for low protein and < 0.05 for reduced intake vs baseline). Cocaine caused seizures in 67% of the high protein animals as compared to 93% and 100% of the low protein and reduced intake animals, respectively (p < 0.05 for high protein vs reduced intake). None of the high protein animals died as compared to 20% and 100% of the low protein and reduced intake animals, respectively (p < 0.05 for high protein vs reduced intake). CONCLUSION: Protein and calorie malnutrition is associated with a reduction in plasma cholinesterase activity and enhanced cocaine toxicity in mice. Further study is needed to determine if dietary factors are partially responsible for variations in plasma cholinesterase activity and cocaine susceptibility in humans.

Animals↗
PubMed1997

Predictors of coronary artery disease in patients with cocaine-associated myocardial infarction. Cocaine-Associated Myocardial Infarction (CAMI) Study Group.

PURPOSE: To identify clinical criteria predictive of underlying coronary artery disease in patients with cocaine-associated myocardial infarction. PATIENTS AND METHODS: Using a retrospective cross-sectional study design at 29 acute care hospitals, we identified 70 patients with cocaine-associated myocardial infarction who had a determination of the presence or absence of coronary artery disease. Clinical characteristics of patients with coronary artery disease (> 50% stenosis on cardiac catheterization or reversible ischemia on stress test) were compared with patients without coronary artery disease (< 50% stenosis on cardiac catheterization). RESULTS: Compared with patients without coronary artery disease (n = 21), patients with coronary artery disease (n = 49) were older (42 versus 31 years; P < 0.001), had more traditional cardiac risk factors (2.3 versus 1.5; P < 0.001), more frequent history of hypertension (odds ratio [OR], 5.3; 95% confidence interval [CI], 1.4 to 20.4); more frequent family history of myocardial infarction (OR, 4.4; 95% CI, 1.3 to 15.1), more bradydysrhythmias (OR, 8.0; 95% CI, 1.0 to 65.5), and more likely to have an inferior infarct location (P = 0.04). CONCLUSION: Age, number of cardiac risk factors, location of myocardial infarction, and bradydysrhythmias predict underlying coronary artery disease in patients with cocaine-associated myocardial infarction. If validated, this knowledge may be used to develop a medically appropriate, cost-effective evaluation strategy for patients following cocaine-associated myocardial infarction.

Adult↗
PubMed1997

Evaluation of patients with chest pain after cocaine use.

Cocaine remains the most common cause of illicit drug-related visits to emergency departments, 40% of which result from chest pain. It is estimated that over half of the 64,000 patients evaluated annually for cocaine-associated chest pain will be admitted to hospitals for the evaluation of myocardial ischemia or infarction, at a health care cost of over eighty million dollars. Although the link between cocaine use and myocardial ischemia is well established, only about 6% of patients with cocaine-associated chest pain will demonstrate biochemical evidence of myocardial infarction. This article focuses on the evaluation of patients with chest pain following cocaine use, and concentrates on ways to improve diagnosis, management, and utilization of health care services.

Chest Pain↗
PubMed1997

Late reopening of fibrosed capsular bags to reposition decentered intraocular lenses.

The infrequent postoperative complication of intraocular lens decentration in the presence of an intact fibrosed capsule has traditionally been treated with lens explantation and exchange for a sulcus-fixated lens. Many of these patients can be managed by reopening the fibrosed capsular bag and repositioning the lens within the bag. These cases can be performed quickly using topical anesthesia regardless of the time since the primary cataract procedure.

Anesthesia, Local↗
PubMed1997

Phacoemulsification in the presence of pseudoexfoliation: challenges and options.

Phacoemulsification in the presence of pseudoexfoliation of the lens presents surgeons with particular challenges. The frequency of intraoperative and postoperative complications such as zonular dialysis, capsular tears, vitreous loss, and intraocular lens (IOL) decentration may be reduced with careful attention to detail and careful surgical technique. Improvements in phacoemulsification technology, IOLs, and new capsular supporting rings allow surgeons to perform safer surgery in these eyes. We present the challenges of and options for managing cataract extraction in the presence of pseudoexfoliation.

Cataract↗
PubMed1997

Toxic ingestions in pregnancy: abortifacient use in a case series of pregnant overdose patients.

OBJECTIVES: To profile young, pregnant patients with an overdose reported to an urban poison center; and to characterize the ingestions and short-term outcomes of these overdose patients. METHODS: A prospective, observational study of female overdose patients was performed from November 1, 1994, through March 31, 1995. Consecutive cases were identified from all calls to the regional poison center (annual call volume = 70,000) regarding intentional overdose in women between the ages of 12 and 30 years. Pregnancy tests were recommended by the poison center during the study period in female patients aged 12-30 years who presented to a health care facility (usually an urban ED) with an intentional overdose. Pregnant patients were then followed during their hospitalizations, and the results of toxicology studies and maternal and short-term fetal outcomes were recorded. RESULTS: Pregnancy tests were obtained for 371 (32%) of 1,142 eligible patients. Of patients with pregnancy tests, 43 (11.6%) were pregnant. Although most cases were comparable to general adult intentional ingestions, 5 of the 43 pregnant patients ingested known abortifacients. Most pregnant patients (35/43, 81%) had toxicity at or below American Association of Poison Control Centers (AAPCC) criteria for minimal toxicity, and all patients recovered completely. CONCLUSION: Pregnancy was a common finding in this sample of young, female, intentional overdose patients reported to our regional poison control center. Frequent use of abortifacients for toxic ingestions has not been previously reported. A pregnancy test should be obtained for all female patients of childbearing age with an intentional ingestion to address the potential association of the ingestion with an unanticipated or undesired pregnancy.

Abortifacient Agents↗
PubMed1997

Herbal preparation use among urban emergency department patients.

OBJECTIVE: To determine the prevalence of herbal preparation use among patients presenting to an urban teaching hospital ED. METHODS: A prospective anonymous survey on herbal preparation use was performed. Consecutive, acutely ill or injured adult (> or = 18 years old) ED patients were offered the survey over a 1-month period. The survey also asked for information related to patient age, ethnicity, gender, employment, education, cigarette smoking history, ethanol consumption, use of illicit drugs, chief complaint, and HIV status. RESULTS: Of 2,473 eligible subjects, 623 (25%) participated. The overall reported prevalence of herbal preparation use among the participants was 21.7%. Women were more likely to use herbal preparations than men (28.5% vs 17.2%, p = 0.013). Prevalence rates in different ethnic populations were: whites, 18.2%; Hispanics, 13.9%; blacks, 26.4%; and Asians, 36.8%. Asians had a significantly higher use rate than the other ethnic groups (p = 0.039). Neither HIV positivity, educational level, employment status, nor age was significantly associated with herbal preparation use. The most commonly reported herbal preparations were goldenseal tea, garlic, and ginger. Several of the herbal preparations reported as used by patients in this study have been associated with severe systemic toxicity in the medical literature. CONCLUSION: Although the survey response rate was low, the prevalence of herbal preparation use among acutely ill or injured patients presenting to this urban ED remains significant. A directed history toward specific herbal preparation use may provide relevant pharmacologic information and uncover cases of herbal-preparation-induced toxicity.

Adult↗
PubMed1997

Effects of Prussian blue and N-acetylcysteine on thallium toxicity in mice.

BACKGROUND: Thallium poisoning is now rare but still occurs as a result of homicide attempts. Prussian blue's efficacy in the treatment of experimental thallium poisoning has been demonstrated in animal models, and its use in humans is supported by anecdotal data. Since thallium binds sulfhydryl groups, the use of N-acetylcysteine is also considered as a potential antidote. STUDY OBJECTIVE: To compare the efficacy of Prussian blue and N-acetylcysteine in a murine model of thallium poisoning. METHODS: Female Swiss albino mice with free access to food and water were used. Two study doses of thallium, given as a subcutaneous injection of thallium acetate dissolved in sterile water, were chosen: 70 mg/kg (LD90) and 85 mg/kg (> LD100). A randomized, placebo controlled study was conducted with survival at 120 h chosen as the outcome measure. Four treatment groups were studied: control, Prussian blue, N-acetylcysteine, and the combination of Prussian blue and N-acetylcysteine. Prussian blue was dissolved in water and given by oral gavage at a dose of 50 mg/kg. N-acetylcysteine was diluted in normal saline and given as intraperitoneal injections of 200 mg/kg. Sterile water by gavage and normal saline by peritoneal injection were given as control treatments whenever an active agent was not given. Survival was recorded over a 120 h study period and compared at 120 h by a Fisher's exact test. RESULTS: At 120 h following subcutaneous injection of thallium 70 mg/kg, only 10% of the control animals survived. Treatment with N-acetylcysteine or Prussian blue increased survival to 35% (p = 0.13) and 50% (p = 0.014), respectively. The addition of N-acetylcysteine to Prussian blue offered no benefit over Prussian blue therapy alone. CONCLUSIONS: Prussian blue was found to decrease mortality from thallium poisoning at a dose equal to the LD90 in this model, but not a dose greater than the LD100. No role for N-acetylcysteine in the treatment of thallium poisoning was demonstrated by this study.

Acetylcysteine↗
PubMed1997

Antidotal efficacy of glutamate and aspartate for colchicine toxicity.

Glutamic and aspartic acids were evaluated for their antidotal efficacy in colchicine toxicity. Female adult inbred mice were treated with ip doses of either 1000 mg glutamic acid (GA) or aspartic acid (AA)/kg bw by various treatment schedules relative to the administration of an ip LD5n of 7.8 mg colchicine/kg bw. Mice were observed for survival and changes in body weight. Pretreatment with AA increased survival by 42% (p = 0.01). Concurrent AA treatment improved survival non-significantly (p = 0.07). With post-exposure AA therapy, however, mortality was increased (p = 0.005). No significant beneficial effects of GA occurred. Early AA therapy improves survival in colchicine poisoned mice, but as delay in treatment is increased, AA efficacy is lost.

Animals↗
PubMed1996

Phacoemulsification performed in a modified waiting room chair.

Patients unable to fully recline represent challenging cases for the cataract surgeon. Various diseases of the heart, lungs, and spine may prevent certain patients from assuming a supine position, complicating the surgical approach and increasing the risk of intraoperative complications. We altered a common waiting room chair to allow these patients to remain in an upright seated position while their heads maintain the usual supine position commonly obtained with patients positioned on an operating room table.

Equipment Design↗
PubMed1996

Refractive aspects of cataract surgery.

The emphasis in cataract surgery has shifted to perfecting the refractive outcome. More accurate lens power calculations and refinement in techniques to reduce or eliminate surgically induced and preexisting astigmatism have moved us closer to the ultimate surgical result-emmetropia. Multifocal lenses and surgically induced multifocal corneas have the potential to eliminate not only myopia and hyperopia but also the loss of accommodation resulting from the pseudophakic state.

Cataract Extraction↗
PubMed1996

Treatment of toad venom poisoning with digoxin-specific Fab fragments.

Toxicity from toad venom poisoning is similar to digoxin toxicity and carries a high mortality rate. We report on six previously healthy men who developed vomiting and bradycardia after ingesting a purported topical aphrodisiac. Each patient had positive apparent digoxin levels and the first four patients died of cardiac dysrhythmias. The last two patients recovered following treatment with digoxin Fab fragments. We analyzed samples of the purported aphrodisiac and found that it was identical to Chan Su, a Chinese medication made from toad venom. To our knowledge, this is the first reported use of digoxin Fab fragments to treat toad venom poisoning.

Adolescent↗