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Biomedical subjects

L Green

Publications and source records attributed to L Green.

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

Plasma oxytocin levels in autistic children.

BACKGROUND: Social impairments are central to the syndrome of autism. The neuropeptide oxytocin (OT) has been implicated in the regulation of social behavior in animals but has not yet been examined in autistic subjects. METHODS: To determine whether autistic children have abnormalities in OT, midday plasma samples from 29 autistic and 30 age-matched normal children, all prepubertal, were analyzed by radioimmunoassay for levels of OT. RESULTS: Despite individual variability and overlapping group distributions, the autistic group had significantly lower plasma OT levels than the normal group. OT increased with age in the normal but not the autistic children. Elevated OT was associated with higher scores on social and developmental measures for the normal children, but was associated with lower scores for the autistic children. These relationships were strongest in a subset of autistic children identified as aloof. CONCLUSIONS: Although making inferences to central OT functioning from peripheral measurement is difficult, the data suggest that OT abnormalities may exist in autism, and that more direct investigation of central nervous system OT function is warranted.

Autistic Disorder↗
PubMed1998

JNC VI guidelines.

Explore the source record for details and available documents.

Antihypertensive Agents↗
PubMed1998

Standardizing the expression and nomenclature of cancer treatment regimens. American Society of Health-System Pharmacist (ASHP), American Medical Association (AMA), American Nurses Association (ANA).

Guidelines for describing cancer chemotherapy regimens in all aspects of drug development, including treatment protocols, order forms, and product labels, are proposed. To complement the approaches to reducing medication errors that have been recommended by ASHP and others, pharmacists at the National Institutes of Health and the National Cancer Institute, with the input of oncology pharmacists from diverse areas of practice, developed guidelines for expressing chemotherapy dosage schedules and treatment regimens. The guidelines present standards that are broadly applicable and can be adopted by other institutions. Clear and unambiguous expression of all medication orders and consistency of treatment descriptions are suggested. Written treatment plans and orders should contain enough information to allow health care providers from diverse disciplines to compare them with published treatment descriptions and investigational protocols and must therefore include planned dosages and schedules expressed in patient-specific units. In general, drug dosages should be expressed as the amount of drug administered from a single container. When ordering drugs that are part of complex or combination-drug regimens, prescribers should write as many of the orders at one time as is possible, so that continuity might be preserved. Standard rules are proposed for describing chemotherapy regimens.

American Medical Association↗
PubMed1998

Pancreatic masses: a multi-institutional study of 364 fine-needle aspiration biopsies with histopathologic correlation.

Only 15% of primary malignant tumors are confined to the gland at the time of presentation. Fine-needle aspiration (FNA) is valuable in confirming the malignant nature of these unresectable lesions. Benign pancreatic lesions and metastatic neoplasms can also be evaluated by fine-needle aspiration. We undertook a retrospective study to evaluate the efficacy of FNA in assessing pancreatic masses. Three hundred and sixty-four radiologically guided FNAs of the pancreas performed between 1986-1996 were reviewed. Surgical material was also evaluated when available and compared to the FNA material. There were 223 men and 141 women. Their ages ranged from 23-90, with a mean of 64 yr. Two hundred and twelve patients (58%) had primary malignant tumors, 183 had adenocarcinomas, 15 had mucinous cystadenocarcinomas, 12 had neuroendocrine tumors, and 2 had pleomorphic giant-cell carcinomas. Ninety-one (43%) had available surgical material which showed adenocarcinoma. Ninety-one patients (25%) had benign aspirates, including 53 showing benign ductal epithelium, 23 showing pancreatitis/inflammation. 10 showing pseudocysts, and 7 showing serous cystadenomas. Surgical material was available in 24 (26%) of these patients. Two of these showed adenocarcinoma. Sixteen aspirates (4%) were suspicious for malignancy, 13 (81%) of which showed adenocarcinoma on follow-up biopsies. Twenty-two aspirates (6%) showed metastatic neoplasms. Twenty-three (6%) had unsatisfactory specimens. Ten (43%) of these had follow-up biopsies, 3 of which were malignant. FNA of primary benign and malignant pancreatic masses is highly sensitive (98%) and specific (100%). Eighty-one percent of the suspicious lesions showed adenocarcinoma on follow-up biopsy. FNA of metastatic neoplasms to the pancreas is also very accurate. This technique can be useful in avoiding unnecessary surgery.

Adult↗
PubMed1998

A behavioral economic analysis of fat appetite in rats.

A behavioral economic analysis of rats' consumption of various fat and sweet solutions was conducted in order to assess whether rats' fat appetite is readily modifiable. According to economic demand theory, changes in the price of a reinforcer will produce substantial changes in its consumption under conditions in which a substitutable reinforcer is available. Results from income-compensated price changes revealed that sucrose, mineral oil and saccharin solutions substituted for a corn oil solution: increases in the price of the corn oil led to large decreases in its consumption and sizable increases in consumption of these alternatives. On the other hand, plain water did not substitute for the corn oil solution: increasing the price of the corn oil did not result in nearly as marked a change in its consumption nor in consumption of the water. Neither the strength of preference for the corn oil under baseline conditions nor the caloric content of the alternative solution predicted whether the alternative reinforcer substituted for the corn oil. Rather, palatability appeared to be a dimension along which substitution was based. These results suggest that fat appetite is modified when palatable alternatives are available, independent of how strongly the fat is preferred.

Animals↗
PubMed1998

Using evidence-based medicine in clinical practice.

This article discusses the cognitive tendencies that lead to inaccurate appraisal of the value of tests or treatments, the role of evidence-based medicine in correcting them, and the need for the primary physician to provide an evidence-based perspective. True clinical outcomes and levels of evidence are defined. The clinical epidemiology of testing is reviewed, with emphasis on sensitivity, specificity, and positive and negative predictive values. These are followed by criteria for usefulness in screening. Treatment evaluation is discussed in terms of absolute risk reduction and number needed to treat.

Clinical Competence↗
PubMed1998

A comparison of posttraumatic stress disorder in veterans with and without spinal cord injury.

The authors assessed effects of paraplegic and quadriplegic spinal cord injuries (SCIs) on posttraumatic stress disorder (PTSD) by comparing severity and prevalence of PTSD in these groups to a sample of controls who experienced traumatic injuries other than SCI. The authors found that veterans with quadriplegia reported significantly less severe current PTSD symptoms than controls who were not significantly different from veterans with paraplegia. These results suggest that sustaining a quadriplegic SCI decreases risk of current PTSD, whereas sustaining a paraplegic SCI is associated with greater risk of PTSD, although the risk is no greater than that incurred from experiencing the trauma itself.

Adult↗
PubMed1998

Rate of gastric emptying is a determinant of postprandial hypotension in non-insulin-dependent diabetes mellitus.

1. Postprandial hypotension is now recognized as an important clinical problem, particularly in the elderly and in patients with autonomic dysfunction. The mechanisms responsible are poorly understood; however, impaired regulation of splanchnic blood flow and the release of gastrointestinal hormones appear to be important. The effect of gastric emptying on the magnitude of the postprandial fall in blood pressure has not been evaluated. 2. The aim of this study was to determine whether there is a relationship between changes in blood pressure and the rate of gastric emptying after ingestion of 75 g of glucose in patients with non-insulin-dependent diabetes mellitus (NIDDM) and both young and older normal subjects. Sixteen patients with recently diagnosed NIDDM, median age 57 (39-79) years, 10 'young' subjects with a median age of 23 (19-26) years and nine 'older' subjects, median age 48 (40-68) years, were measured simultaneously for gastric emptying of 75 g of glucose in 350 ml of water blood pressure and blood glucose concentrations, commencing at approximately 10.00 hours after an overnight fast. Measurements of blood pressure were made in the sitting position immediately before glucose ingestion and at 15 min intervals up to 180 min. 3. Gastric emptying of glucose was not significantly different between the three groups [50% emptying time (T50): 95 +/- 7.3 min in patients with NIDDM compared with 120 +/- 13.2 min in the 'young' group and 97 +/- 8.1 min in the 'older' group]. There was a significant fall in mean blood pressure after the glucose load in the patients with NIDDM (P < 0.0001) and the 'older' normal subjects (P < 0.05), but not the 'young' normal subjects. Postprandial hypotension (fall in systolic blood pressure > or = 20 mmHg) was evident in seven (44%) patients with NIDDM and three (33%) 'older' normal subjects. The area under the change in mean blood pressure curve was related significantly to the gastric emptying T50 (r = 0.67, P < 0.005) in the patients with NIDDM, but not in either control group. 4. In conclusion, in patients with recently diagnosed NIDDM the fall in blood pressure after an oral glucose load is (i) greater than in both young and older normal subjects and (ii) related to the rate of gastric emptying.

Adult↗
PubMed1998

Antibiotic treatment influences outcome in murine sepsis: mediators of increased morbidity.

Different antibiotic treatments may affect the survival and physiological responses of Balb/c mice following cecal ligation and puncture (CLP). The broad spectrum imipenem (IMP) was compared with a triple antibiotic mixture of gentamicin, clindamycin, and ciprofloxacin (3AB). Control mice received injections of 5% dextrose (D5W). After CLP with a 25 gauge needle, Mini-Mitters were implanted to measure temperature and activity. Therapy began with 1 mL injections of antibiotics or D5W 2 h post-CLP and continued every 12 h for 3 days. Survival was higher in IMP mice than in 3AB or D5W mice. Starting with the injection 12 h after CLP, 3AB always induced a profound hypothermic response not observed with D5W or IMP. Nocturnal activity levels were higher in IMP mice compared with 3AB or D5W mice during the first night following CLP. To determine the cause of this hypothermic response and to further investigate the acute effects that antibiotic choice may have on murine physiology, the kinetic appearance of IL-1, IL-6, TNF, and KC as well as lipopolysaccharide (LPS), were measured in the plasma and peritoneum of mice sacrificed at 0, .5, and 1.5 h after antibiotic injection at 24 h post-CLP. Cytokine and LPS concentrations in 3AB mice were not significantly different at any of the three time points when compared with IMP or D5W mice. Our data demonstrate that antibiotic therapy consisting of 3AB produces greater morbidity and mortality compared with therapy consisting of IMP. However, the mechanism of these alterations is not due to elevated systemic levels of cytokines or LPS.

Animals↗
PubMed1998

Retinal changes mimicking diabetic retinopathy in two nondiabetic, growth hormone-treated patients.

A role for GH in the pathogenesis of diabetic retinopathy has long been postulated. Previous clinical studies, however, have been confounded by hyperglycemia. We have identified 2 cases of retinopathy associated with exogenous GH therapy in nondiabetic patients. Cases were identified through the MedWatch drug surveillance system of the U.S. Food and Drug Administration. Causality by concomitant medications was excluded by a search of the literature and the FDA data base. The first patient, an obese, 31-yr-old male with traumatic hypothalamic injury, presented with nonproliferative retinopathy and macular edema, resulting in decreased visual acuity (OD 20/40-1; OS count fingers), which required laser surgery. Human GH had been initiated at 0.009 mg/ kg.day, 14 months earlier, and titrated to 0.017 mg/kg.day. The second patient, a nonobese, 11-yr-old girl receiving GH for the management of short stature in Turner's Syndrome, presented with neovascularization. GH doses were 0.033 mg/kg.day for the first 17 months and 0.043 mg/ kg.day for the following 5 months. Cumulative laboratory and clinical observations suggest that GH and related peptides have a role in retinal pathology independent of the degree of glucose tolerance.

Adult↗
PubMed1998

Exposure to dioxin and nonneoplastic mortality in the expanded IARC international cohort study of phenoxy herbicide and chlorophenol production workers and sprayers.

The authors studied noncancer mortality among phenoxyacid herbicide and chlorophenol production workers and sprayers included in an international study comprising 36 cohorts from 12 countries followed from 1939 to 1992. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin or higher chlorinated dioxins (TCDD/HCD) was discerned from job records and company questionnaires with validation by biologic and environmental measures. Standard mortality ratio analyses suggested a moderate healthy worker effect for all circulatory diseases, especially ischemic heart disease, among both those exposed and those not exposed to TCDD/HCD. In Poisson regression analyses, exposure to TCDD/HCD was not associated with increased mortality from cerebrovascular disease. However, an increased risk for circulatory disease, especially ischemic heart disease (rate ratio [RR] 1.67, 95% confidence interval [Cl] 1.23-2.26) and possibly diabetes (RR 2.25, 95% Cl 0.53-9.50), was present among TCDD/HCD-exposed workers. Risks tended to be higher 10 to 19 years after first exposure and for those exposed for a duration of 10 to 19 years. Mortality from suicide was comparable to that for the general population for all workers exposed to herbicides or chlorophenols and was associated with short latency and duration of exposure. More refined investigations of the ischemic heart disease and TCDD/HCD exposure association are warranted.

Adult↗
PubMed1997

Handling of gene-transfer products by the National Institutes of Health Clinical Center pharmacy department.

Policies and procedures for handling gene-transfer products at the National Institutes of Health (NIH) Clinical Center pharmacy department are described. The pharmacy at the Clinical Center is responsible for handling in vivo gene-transfer delivery systems, which are gene-transfer products that are prepared for direct administration to patients. The gene-transfer products currently handled by the pharmacy are investigational and are composed of viruses containing the gene encoding either of the melanoma antigens MART-1 and gp100. The pharmacy has prepared guidelines, based on the principles of aseptic technique and FDA guidelines for manufacturing facilities, intended to help pharmacy personnel safely dilute a concentrated gene-transfer product into a dose suitable for administration. Before a product is handled, the biological safety level is determined and a biohazard sign is posted. Worksheets detailing all supplies, calculations for dilutions, and procedures that will be required are prepared in advance; the worksheets are part of a drug fact sheet prepared for all investigational drugs dispensed. Personnel must be properly trained and dressed in protective clothing. Aseptic technique and decontamination procedures are used as specified in the guidelines, and all materials used are disposed of as biohazardous waste. All work is documented. If a worker is accidentally exposed, standard procedures are followed. The handling of gene-transfer products at the NIH Clinical Center pharmacy is based on the principles of aseptic technique, FDA guidelines, and experience.

Containment of Biohazards↗
PubMed1997

Cancer mortality in workers exposed to phenoxy herbicides, chlorophenols, and dioxins. An expanded and updated international cohort study.

The authors examined cancer mortality in a historical cohort study of 21,863 male and female workers in 36 cohorts exposed to phenoxy herbicides, chlorophenols, and dioxins in 12 countries. Subjects in this updated and expanded multinational study coordinated by the International Agency for Research on Cancer were followed from 1939 to 1992. Exposure was reconstructed using job records, company exposure questionnaires, and serum and adipose tissue dioxin levels. Among workers exposed to phenoxy herbicides contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or higher chlorinated dioxins, mortality from soft-tissue sarcoma (6 deaths; standardized mortality ratio (SMR) = 2.03, 95% confidence interval (CI) 0.75-4.43) was higher than expected from national mortality rates. Mortality from all malignant neoplasms (710 deaths; SMR = 1.12, 95% CI 1.04-1.21), non-Hodgkin's lymphoma (24 deaths; SMR = 1.39, 95% CI 0.89-2.06), and lung cancer (225 deaths; SMR = 1.12, 95% CI 0.98-1.28) was slightly elevated. Risks for all neoplasms, for sarcomas, and for lymphomas increased with time since first exposure. In workers exposed to phenoxy herbicides with minimal or no contamination by TCDD and higher chlorinated dioxins, mortality from all neoplasms (398 deaths; SMR = 0.96, 95% CI 0.87-1.06), non-Hodgkin's lymphoma (9 deaths; SMR = 1.00), and lung cancer (148 deaths; SMR = 1.03) was similar to that expected, and mortality from soft-tissue sarcoma was slightly elevated (2 deaths; SMR = 1.35). In a Poisson regression analysis, workers exposed to TCDD or higher chlorinated dioxins had an increased risk for all neoplasms (rate ratio = 1.29, 95% CI 0.94-1.76) compared with workers from the same cohort exposed to phenoxy herbicides and chlorophenols but with minimal or no exposure to TCDD and higher chlorinated dioxins. These findings indicate that exposure to herbicides contaminated with TCDD and higher chlorinated dioxins may be associated with a small increase in overall cancer risk and in risk for specific cancers.

Australia↗
PubMed1997

The physician's role in minimizing prehospital delay in patients at high risk for acute myocardial infarction: recommendations from the National Heart Attack Alert Program. Working Group on Educational Strategies To Prevent Prehospital Delay in Patients at High Risk for Acute Myocardial Infarction.

Physicians and other health care professionals play an important role in reducing the delay to treatment in patients who have an evolving acute myocardial infarction. A multidisciplinary working group has been convened by the National Heart Attack Alert Program (which is coordinated by the National Heart, Lung, and Blood Institute of the National Institutes of Health) to address this concern. The working group's recommendations target specific groups of patients: those who are known to have coronary heart disease, atherosclerotic disease of the aorta or peripheral arteries, or cerebrovascular disease. The risk for acute myocardial infarction or death in such patients is five to seven times greater than that in the general population. The working group recommends that these high-risk patients be clearly informed about symptoms that they might have during a coronary occlusion, steps that they should take, the importance of contacting emergency medical services, the need to report to an appropriate facility quickly, treatment options that are available if they present early, and rewards of early treatment in terms of improved quality of life. These instructions should be reviewed frequently and reinforced with appropriate written material, and patients should be encouraged to have a plan and to rehearse it periodically. Because of the important role of the bystander in increasing or decreasing delay to treatment, family members and significant others should be included in all instruction. Finally, physicians' offices and clinics should devise systems to quickly assess patients who telephone or present with symptoms of a possible acute myocardial infarction.

Algorithms↗
PubMed1997

Selections from current literature: the fight over fat: is pharmacological lipid lowering useful for coronary primary prevention?

The optimistic bias favouring intervention in medicine has long been known, and it may be fair to say that compensating for this characteristic tendency of human judgement is a primary reason for the need for blind trials and evidence-based medicine. Packer has observed that "Physicians frequently decide to prescribe a drug because of the therapeutic gains it might provide (based on pathophysiological theories) rather than the benefits it actually delivers (as demonstrated by the results of controlled clinical trials)." In the present case, sorting out evidence from optimism, what we know from what we wish to be so, is a challenging task for the clinician trying to determine what to recommend to his/her patients in day-to-day practice. In the case of lipid-lowering therapies, the optimistic preference for positive results is widely evident. Ravsknov showed that trials finding a positive result have been cited six times as often as equally sound trials finding no effect. (The LRC alone was cited 612 times in the first 4 years after its publication.) The LRC trial results themselves (interpreted with appropriate statistical tests) were inconclusive and difficult to generalize, but were presented as definitive and generalizable with certainty. Subsequent papers have been more circumspect, but none the less have generally focused on CHD reduction (a positive result) while giving minimal discussion to overall mortality. In this vein, the finding of increase in mortality due to violence has been dismissed outright (e.g. p. 1243 of the Helsinki Study) though it has appeared in fibrate and bile acid sequestrant trials, there is a dose-response relationship, and the same effect is observed in non-human primates. Clinically, increased violence as a side effect may no longer be relevant, as recent analyses suggest that it is specific to fibrates (and to hormones, not used any longer); the currently favoured statin drugs do not so far appear to share this side effect, but it was dismissed by enthusiasts for lipid lowering long before such data existed. Estimates of the effect of lipid lowering are often inflated by including secondary prevention studies, as well as by assertions that 5-year NNTs underestimate the benefits of lipid lowering although analysis of primary prevention trials indicates that the full benefit of risk reduction is evident within 5 years. What is the family doctor to do? Clearly, not all the claims in the literature can be taken at face value, particularly when advanced by content-area experts invested in lipid research. Hence, it seems to fall to the family physician to translate these claims into honest expectations of benefit for the variety of patients we see, with their various levels of risk. Perhaps the best solution is to be found in combining the sound clinical epidemiology approach taken by Rembold with the honest extrapolation of effect according to baseline risk used by the CTF. We do now have the necessary estimates of NNT for primary prevention to inform our higher-risk patients: an NNT of 53 for CHD events certainly does justify our recommending statin drugs to middle-aged significantly hyperlipidaemic men, especially if they have multiple risk factors. The situation is less clear for lower-risk patients, such as women, the elderly and mildly dyslipidaemic men with no or few other risk factors. Even including the recent data on the statin drugs, the 5-year NNT for prevention of a CHD event in average-risk mildly hyperlipidaemic clinical populations (extrapolated using the CTF method) is 212. What intervention if any the family physician wishes to make, and the patient wishes to take, should be a matter negotiated between them, informed by the family physician's realistic appraisal of the patient's likely expected benefit.

Anticholesteremic Agents↗
PubMed1997

Validity of self-reported hysterectomy and tubal sterilisation. The Survey of Women's Health Study Group.

Both hysterectomy and tubal sterilisation offer significant protection from ovarian cancer, and the risk of cardiovascular disease in women is lowered after hysterectomy. Since little is known about the accuracy of women's self-reports of these procedures, we assessed their reliability and validity using data obtained in a case-control study of ovarian cancer. There was 100 per cent repeatability for both positive and negative histories of hysterectomy and tubal sterilisation among a small sample of women on reinterview. Verification of surgery was sought against surgeons' or medical records, or if these were unavailable, from randomly selected current general practitioners for 51 cases and 155 controls reporting a hysterectomy and 73 cases and 137 controls reporting a tubal sterilisation. Validation rate for self-reported hysterectomy against medical reports (32 cases, 96 controls) was 96 per cent (95 per cent confidence interval (CI) 91 to 99) and for tubal sterilisation (32 cases, 77 controls) it was 88 per cent (CI 81 to 93), which is likely to be an underestimate. Although findings are based on small numbers of women for whom medical reports could be ascertained, they are consistent with other findings that suggest women have good recall of past histories of hysterectomy and tubal sterilisation; this allows long-term effects of these procedures to be studied with reasonable accuracy from self-reports.

Adolescent↗