Dietary manipulation of plasma albumin concentration

The variation in plasma albumin concentrations of rats fed a wide range of protein- and energy-deficient diets has been investigated. These changes have been correlated with simultaneous effects of the diets on growth rate, carcass composition, protein and energy balance, and plasma concentration of insulin corticosterone and triiodothyronine (T3). Although rats eating diets of low protein content and libitum developed hypoalbuminemia, those fed equivalent amounts of protein at low energy intakes had plasma albumin concentrations nearer, or equal to control values. Data from the balance study showed that for hypoalbuminemia to occur, not only had dietary protein to be inadequate, it was also necessary for energy consumption to be in excess of requirements. It is suggested that in protein-deficient animals, energy consumed in excess of the amount required for maintenance and the protein-limited growth rate initiates a metabolic response which results in inappropriate use of the meagre protein intake. This "dysadapted" state, in the rat, appears to be indicated by elevated plasma T3 values. The implication that kwashiorkor-like symptoms can be generated by a relative as opposed to a total energy excess is discussed in relation to the appearance of this disease in humans.     

Sex differences and similarities in the management and outcome of stroke patients

BACKGROUND AND PURPOSE: Previous studies have documented sex differences in the management and outcome of patients with cardiovascular disease. However, little data exist on whether similar sex differences exist in stroke patients. We conducted a study to determine whether sex differences exist in patients with acute stroke admitted to Ontario hospitals. METHODS: Using linked administrative databases, we performed a population-based cohort study. The databases contained information on all 44 832 patients discharged from acute-care hospitals in Ontario between April 1993 and March 1996 with a most responsible diagnosis of acute stroke. The main outcomes measured consisted of sex differences in comorbidities, the use of rehabilitative services, the use of antiplatelet therapy and anticoagulants (in elderly stroke survivors aged > or =65 years only), discharge destination, and mortality. RESULTS: Male stroke patients were more likely than female stroke patients to have a history of ischemic heart disease (18.1% versus 15.3%, respectively; P<0.001) and diabetes mellitus (20.1% versus 18. 7%, respectively; P<0.001), whereas female patients were more likely than male patients to have hypertension (33.8% versus 30.0%, respectively; P<0.001) and atrial fibrillation (12.9% versus 10.2%, respectively; P<0.001). There were no sex differences in the usage of in-hospital rehabilitative services. The overall 90-day postdischarge use of aspirin and ticlopidine was similar in stroke survivors aged 65 to 84 years. However, among stroke survivors aged > or =85 years, men were more likely than women to receive aspirin (36. 0% versus 30.7%, respectively; P<0.001) and ticlopidine (9.2% versus 6.8%, respectively; P=0.007). Use of warfarin was similar for the two sexes. Men were more likely than women to be discharged home (50. 6% versus 40.9%, respectively; P<0.001) and less likely to be discharged to chronic care facilities (16.8% versus 25.2%, respectively; P<0.001). The risk of death 1 year after stroke was somewhat lower in women than men (adjusted odds ratio 0.939, 95% CI 0.899 to 0.980; P=0.004). The mortality differences were greatest among elderly stroke patients. CONCLUSIONS: Elderly men are more likely than elderly women to receive aspirin and ticlopidine and equally like to receive warfarin after a stroke. Despite these differences, elderly women have a better 1-year survival after a stroke.     

Rate of stroke recurrence in patients with primary intracerebral hemorrhage

BACKGROUND AND PURPOSE: Primary intracerebral hemorrhage (PICH) is a devastating illness with high early mortality. Hypertension is a major risk factor both for ischemic cerebrovascular disease and for intracranial hemorrhage. Survivors of PICH are at risk for both recurrent hemorrhage and ischemic cerebrovascular disease. We sought to determine the rate of recurrence of ICH or cerebral ischemia in a cohort of PICH patients at the Toronto Hospital, Toronto, Canada. METHODS: A retrospective search of computerized hospital records from 1986 to 1996 for patients with a discharge diagnosis of intracerebral hemorrhage (International Classification of Diseases, Ninth Revision-Clinical Modification [ICD-9-CM] code 431) was conducted to identify the index cases. Charts were abstracted for demographic and clinical characteristics. CT scans, MR scans, or radiologist reports were reviewed. To determine recurrence, the database was linked to the Ontario Provincial Government Vital Statistics Registry and to the Canadian Institute for Health Information database of hospital discharge abstracts. Logistic regression analysis was used to identify predictive factors for mortality after PICH. A Cox proportional hazards model was fitted to identify predictive factors for recurrent ICH or stroke. RESULTS: A total of 746 charts were identified by computer search. After abstraction, 423 index patients with PICH were identified. Of these, 27.4% died in the first 30 days of their admission. Predictors of death were age, intraventricular rupture of hemorrhage, and trilobar hemorrhage. The recurrence rate for PICH was 2.4% (95% CI 1.4% to 3. 9%) per year, whereas the recurrence rate for ischemic cerebrovascular disease was 3.0% (95% CI 1.8% to 4.7%) per year. The only significant predictor of readmission for ICH was lobar location of the index hemorrhage, with a hazard ratio of 3.8 (95% CI 1.2 to 12.0). CONCLUSIONS: PICH has a high 30-day mortality rate. Survival from the initial insult portends a moderate risk of recurrence of 2. 4% per year for PICH and 3.0% per year for ischemic cerebrovascular disease. Patients with PICH are at risk for both ischemic stroke or TIA and recurrent hemorrhage; thus, PICH may be a marker for ischemic stroke. Patients with lobar hemorrhage have a 3.8-fold increased risk of recurrent ICH.     

Previous exposure to VTA amphetamine enhances cocaine self-administration under a progressive ratio schedule in an NMDA, AMPA/kainate, and metabotropic glutamate receptor-dependent manner.

Previous exposure to amphetamine (AMPH) in the ventral tegmental area (VTA) enhances cocaine self-administration in a D(1) dopamine receptor-dependent manner. The present study examined the contribution of VTA NMDA, AMPA/kainate, and metabotropic glutamate (mGlu) receptors to this effect. Rats in different groups received three intra-VTA injections, one every third day, of either saline (0.5 microl/side), AMPH (2.5 microg/0.5 microl/side), AMPH+CPP (NMDA receptor antagonist; 10 microM or 100 microM/0.5 microl/side), AMPH+CNQX (AMPA/kainate receptor antagonist; 0.3 mM or 1 mM/0.5 microl/side), AMPH+MCPG (mGlu receptor antagonist; 0.5 mM or 50 mM/0.5 microl/side), or the glutamate receptor antagonists alone. Starting 7-10 days after the last pre-exposure injection, rats were trained to self-administer cocaine (0.3 mg/kg/infusion) and then tested under a progressive ratio (PR) schedule of reinforcement for 6 consecutive days. As reported previously, VTA AMPH pre-exposed rats worked more and obtained more infusions of cocaine than saline pre-exposed animals. Coadministration of CPP, CNQX, or MCPG with AMPH during pre-exposure dose-dependently blocked this enhancement of cocaine self-administration. Rats pre-exposed to the glutamate receptor antagonists alone did not differ on the test days from the saline pre-exposed controls. These results indicate that, in a manner paralleling the induction of sensitization of the locomotor stimulating effects of AMPH, activation of NMDA, AMPA/kainate, and mGlu receptors during pre-exposure to AMPH in the VTA is necessary for the enhancement of cocaine self-administration to develop.     

Health-Related Quality of Life in Publicly Insured Children With Special Health Care Needs

Our objective was to examine health-related quality of life (HRQOL) in publicly insured children with special health care needs (CSHCN). Data were obtained from 183 caregivers of CSHCN (M = 10 years; 54% African American) in urban health clinics. CSHCN had poorer physical and psychosocial HRQOL than children in a normative sample. In regression analysis, children who had more health problems and more health visits in the previous 12 months had poorer physical HRQOL. Poorer psychosocial HRQOL was associated with more health problems and urban life stressors. Implications for practice and policy are discussed.     

A literature review of the prehospital use of neuromuscular blocking agents by air medical personnel to facilitate endotracheal intubation

Air medical personnel in the United States have used neuromuscular blocking agents to facilitate endotracheal intubation in the field for more than a decade. This literature review examines 15 studies to investigate their experience and explores the following specific areas: the intubation success rate in patients who did or did not receive these agents, the intubation success rate of air medical personnel before and after they incorporated these agents into their practice, the neuromuscular blocking agents and adjunct medications used by air medical personnel, and the disposition of patients who could not be intubated after an agent was given. The data suggest that, overall, air medical personnel use these agents safely and effectively. Suggestions are offered for future studies, including examining ground time when agents are used to facilitate intubation, complications of their use in this setting, and the use of simulators to train personnel in the administration of these medications.     

Evaluation of a "heads-up" display for cardiopulmonary bypass

Multiple variables must be analyzed during cardiopulmonary bypass in order to judge the adequacy of perfusion. Variables when viewed singly can be confusing and lead to inaccurate representation of the physiological status of the patient. Communication between the perfusionist and members of the surgical team requires accuracy and complete presentation of pertinent data. Toward this goal of improving the assimilation and processing of information during cardiopulmonary bypass, a multivariable computer-aided "Heads-up Display" (HUD) was developed. Modern jet pilots use heads-up display for rapid assimilation of information when making judgments about the performance of their aircraft and weapons systems. Heads-up display is an electronically generated display that is superimposed upon a pilot's forward field of view. An analogy between a jet pilot and a perfusionist can be made. A geometric form, a hexagon, is used as part of the heads-up display for cardiopulmonary bypass (CPB-HUD). The polygon represents a performance evaluation graph. Each of the six "spokes of a wheel" represents a physiological parameter. The represented variables are: cardiac index, peripheral vascular resistance, hematocrit, dynamic operating blood level, venous saturation, and mean arterial pressure. The perfusionist inputs target values. Target values are then compared to actual values and expressed as a percentage. If all targeted values are achieved, the graphical representation is a hexagon. The surgical team rapidly recognizes abnormal patterns that are outside individual target values. They include, but are not limited to, patterns of: vasoconstriction, vasodilatation, hypovolemia, decreased oxygen carrying capacity, and several others. The CPB-HUD has proved to be of value for planning, real time evaluation, retrospective analysis of cardiopulmonary bypass benchmark data, and as an aid in the teaching of new personnel concerned with cardiopulmonary bypass.     

Accuracy and reliability of forensic handwriting comparisons

Forensic handwriting examination involves the comparison of writing samples by forensic document examiners (FDEs) to determine whether or not they were written by the same person. Here we report the results of a large-scale study conducted to assess the accuracy and reliability of handwriting comparison conclusions. Eighty-six practicing FDEs each conducted up to 100 handwriting comparisons, resulting in 7,196 conclusions on 180 distinct comparison sets, using a five-level conclusion scale. Erroneous “written by” conclusions (false positives) were reached in 3.1% of the nonmated comparisons, while 1.1% of the mated comparisons yielded erroneous “not written by” conclusions (false negatives). False positive rates were markedly higher for nonmated samples written by twins (8.7%) compared to nontwins (2.5%). Notable associations between training and performance were observed: FDEs with less than 2 y of formal training generally had higher error rates, but they also had higher true positive and true negative rates because they tended to provide more definitive conclusions; FDEs with at least 2 y of formal training were less likely to make definitive conclusions, but those definitive conclusions they made were more likely to be correct (higher positive predictive and negative predictive values). We did not observe any association between writing style (cursive vs. printing) and rates of errors or incorrect conclusions. This report also provides details on the repeatability and reproducibility of conclusions, and reports how conclusions are affected by the quantity of writing and the similarity of content.

Forensic science is under scrutiny, particularly for pattern-based disciplines in which source conclusions are reported. The National Research Council report Strengthening Forensic Science in the United States: A Path Forward (1) stated that “The scientific basis for handwriting comparisons needs to be strengthened” and noted that “there has been only limited research to quantify the reliability and replicability of the practices used by trained document examiners.” The President’s Council of Advisors on Science and Technology (PCAST) report Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods (2) expressed concerns regarding the validity and reliability of conclusions made by forensic examiners, and called for empirical testing: “The only way to establish the scientific validity and degree of reliability of a subjective forensic feature-comparison method—that is, one involving significant human judgment—is to test it empirically by seeing how often examiners actually get the right answer. Such an empirical test of a subjective forensic feature-comparison method is referred to as a ‘black-box test.’” The National Commission on Forensic Science also called for such testing (3). Although the accuracy and reliability of conclusions made by forensic document examiners (FDEs) have been the focus of multiple studies over the years (4–10), the designs of those studies are notably different from this study (and from PCAST’s recommendations), and therefore the resulting rates are not directly comparable (in particular, when comparing open-set to closed-set studies, comparing studies based on one-to-one vs. one-to-many examinations, and comparing studies that use notably different conclusion scales; see SI Appendix, Appendix B for a summary).This study was conducted to provide data that can be used to assess the scientific validity of handwriting comparisons, for use by policy makers, laboratory managers, the legal community, and FDEs. This study follows the approach used in the previous FBI Laboratory–Noblis latent print black box study (11) and later recommended by the PCAST report. The design utilizes open-set, one-to-one document comparisons to evaluate the conclusions reached by practicing FDEs when comparing writing samples selected to be broadly comparable to casework. The primary purposes of the study are to measure the accuracy of conclusions by FDEs when comparing handwriting samples and to assess reliability by measuring the reproducibility (interexaminer variability) and repeatability (intraexaminer variability) of those conclusions. Secondary purposes include reporting any associations between the accuracy of the decisions in this study, factors related to the participants (such as training or experience), and factors related to the samples (such as quantity of writing, comparability of content, limitations, or style of writing).