Comparison of arterial hypotension incidence during general anesthesia induction - target-controlled infusion vs. bolus injection of propofol: a randomized clinical trial.

BACKGROUND: The incidence of arterial hypotension during induction of general anesthesia is influenced by the method of propofol administration, but there is a dearth of randomized clinical trials comparing bolus injection and target-controlled infusion in relation to arterial hypotension. This study seeks to compare the incidence of arterial hypotension between these two methods of propofol administration. METHODS: This prospective, randomized, single-center, non-blinded study included 60 patients (aged 35 to 55 years), classified as ASA physical status I or II, who were undergoing non-cardiac surgeries. They were randomly allocated using a computer to two groups based on the method of propofol administration during the induction of general anesthesia: the Target Group, receiving target-controlled infusion at 4 µg.mL-1, and the Bolus Group, receiving a bolus infusion of 2 mg.kg-1. Both groups also received midazolam 2 mg, fentanyl 3 µg.kg-1, and rocuronium 0.6 mg.kg-1. Over the first 10 minutes of anesthesia induction, Mean Arterial Pressure (MAP), Heart Rate (HR), level of Consciousness (qCON), and Suppression Rate (SR) were recorded every 2 minutes. RESULTS: Twenty-seven patients remained in the TCI group, while 28 were in the Bolus group. Repeated measure analysis using mixed-effects models could not reject the null hypothesis for the effect of group-time interactions in MAP (p = 0.85), HR (p = 0.49), SR (p = 0.44), or qCON (p = 0.72). The difference in means for qCON (60.2 for TCI, 50.5 for bolus, p < 0.001), MAP (90.3 for TCI, 86.2 for bolus, p < 0.006), HR (76.2 for TCI, 76.9 for bolus, p = 0.93), and SR (0.01 for TCI, 5.5 for bolus, p < 0.001), irrespective of time (whole period means), revealed some significant differences. CONCLUSION: Patients who received propofol bolus injection exhibited a lower mean arterial pressure, a greater variation in the level of consciousness, and a higher suppression rate compared to those who received it as a target-controlled infusion. However, the interaction effect between groups and time remains inconclusive.

One-eye-set sugarcane susceptibility to weed interference.

The new technology of sugarcane planting, known as one-eye-set seedlings, offer a high standard of plant health and vegetative vigor. However, there are no reports in the literature that evaluate the weed competition with one-eye-set sugarcane seedlings, and the periods in which weed communities need to be controlled in this system. Two interference experiments were conducted in field conditions. The first experiment determined the periods of weed interference of an infesting community predominated by Ipomoea hederifolia and Merremia aegyptia in sugarcane. In the second experiment, these same species competed with plants of the same sugarcane cultivar. Productivity and qualitative aspects of production were evaluated. The critical period of interference prevention in one-eye-set sugarcane system was 103 days, with weed community interference starting at 35 days and lasting until 138 days after planting. Weed coexistence during the entire sugarcane cycle reduced productivity by 60% and affected qualitative characteristics such as the total reducing sugars. Both species affected the vegetative development of the crop, mainly the tillering. I. hederifolia plants developed ahead of the M. aegyptia plants but in late evaluations the interference caused by M. aegyptia (77%) was greater (P<0.01) than that caused by I. hederifolia (72%).

Shoot and root interference of morning glory on the initial growth of sugarcane

ABSTRACT Among weeds, morning glories comprise a very important group of climbing plants that infest sugarcane crops. The objective of this study was to evaluate the shoot and root interference of Merremia cissoides on the initial growth of sugarcane cultivar RB 966928. The experiment consisted of five treatment groups: (i) sugarcane monocropping, (ii) morning glory monocropping, (iii) sugarcane intertwined with morning glory but inseparate boxes, (iv) sugarcane intertwined with morning glory in attached boxes and (v) sugarcane with morning glory in attached boxes with morning glory prevented from intertwining with the sugarcane. The experimental design consisted of randomized blocks with four replicates. Merremia cissoides adversely affected the initial growth of the RB 966928 sugarcane starting at 90 days after transplanting (DAT). This effect increased with the time of intercropping, reaching at 180 DAT with a reduction of 57.3% in height,15.5% in stalk diameter, 90.4% in leaf areas, 86.6 and 75.2% in stalk and leaf dry mass, respectively. These reductions primarily due to the weed intertwining with the sugarcane plants because the weed had a physical choking and shading effect. This negative effect of morning glory on the sugarcane plants increased when they shared the substrate (i.e., when they competed for space and water), which also adversely affected weed growth, reducing 50.2% leaf areas and 42.1% shoot dry mass. The leaf area and the stalk and leaf dry mass of sugarcane are the characteristics more sensitive to the weed interference. Thus, both the shoot and root of M. cissoides interferes negatively in the growth of sugarcane, with the effect proportional to the period of coexistence, highlighting the detrimental effect on the stem (greater economic interest), and may also compromise the mechanical harvesting of the crop.

Shoot and root interference of morning glory on the initial growth of sugarcane.

Among weeds, morning glories comprise a very important group of climbing plants that infest sugarcane crops. The objective of this study was to evaluate the shoot and root interference of Merremia cissoides on the initial growth of sugarcane cultivar RB 966928. The experiment consisted of five treatment groups: (i) sugarcane monocropping, (ii) morning glory monocropping, (iii) sugarcane intertwined with morning glory but inseparate boxes, (iv) sugarcane intertwined with morning glory in attached boxes and (v) sugarcane with morning glory in attached boxes with morning glory prevented from intertwining with the sugarcane. The experimental design consisted of randomized blocks with four replicates. Merremia cissoides adversely affected the initial growth of the RB 966928 sugarcane starting at 90 days after transplanting (DAT). This effect increased with the time of intercropping, reaching at 180 DAT with a reduction of 57.3% in height,15.5% in stalk diameter, 90.4% in leaf areas, 86.6 and 75.2% in stalk and leaf dry mass, respectively. These reductions primarily due to the weed intertwining with the sugarcane plants because the weed had a physical choking and shading effect. This negative effect of morning glory on the sugarcane plants increased when they shared the substrate (i.e., when they competed for space and water), which also adversely affected weed growth, reducing 50.2% leaf areas and 42.1% shoot dry mass. The leaf area and the stalk and leaf dry mass of sugarcane are the characteristics more sensitive to the weed interference. Thus, both the shoot and root of M. cissoides interferes negatively in the growth of sugarcane, with the effect proportional to the period of coexistence, highlighting the detrimental effect on the stem (greater economic interest), and may also compromise the mechanical harvesting of the crop.

Validación de una metodología analítica para la cuantificación de polifenoles totales, en procesos de extracción asistida por microondas sobre frutos de la especie colombiana Vaccinium meridionale / Validation of an analytical method for quantification of total polyphenols in microwave-assisted extraction processes for the Colombian species Vaccinium meridionale

En este trabajo se muestra el desarrollo y la validación de un método analítico para la cuantificación de polifenoles totales con el reactivo de Folin-Ciocalteu (F-C),en procesos de extracción asistida por microondas (MAE), sobre frutos de la especie colombiana Vaccinium meridionale. Los resultados obtenidos en los parámetros selectividad, linealidad, repetibilidad y exactitud muestran que la metodología propuesta es confiable para evaluar el efecto de las condiciones de extracción sobre la cantidad de polifenoles removidos.

In this work, we show the development and validation of an analytical method for quantification of total polyphenols with Folin-Ciocalteu reagent (F-C) in microwave-assisted extraction processes for Colombian species Vaccinium meridionale. Experimental results of selectivity, linearity, repeatability and accuracy evidence that the methodology proposed is reliable to evaluate the effect of the extraction conditions over the quantity of polyphenols removed.

Effect of pH and Temperature on Enzyme Activity of Chitosanase Produced Under Solid Stated Fermentation by Trichoderma spp.

Trichoderma strains were extensively studied as biocontrol agents due to their ability of producing hydrolytic enzymes, which are considered key enzymes because they attack the insect exoskeleton allowing the fungi infection. The present work aimed to evaluate the ability of chitosanase production by four Trichoderma strains (T. harzianum, T. koningii, T. viride and T. polysporum) under solid stated fermentation and to evaluate the effect of pH and temperature on enzyme activity. pH strongly affected the enzyme activity from all tested strains. Chitosanase from T. harzianum and T. viride presented optimum activity at pH 5.0 and chitosanase from T. koningii and T. polysporum presented optimum activity at pH 5.5. Temperature in the range of 40-50°C did not affect enzyme activity. T. polysporum was found as the most promising strain to produce chitosanase with maximal enzyme activity of about 1.4 IU/gds, followed by T. viride (~1.2 IU/gds) and T. harzianum (1.06 IU/gds).

Mild cognitive impairment: directions for future research.

Mild cognitive impairment (MCI), an intermediate state between normal aging and dementia, is characterized by acquired cognitive deficits, without significant decline in functional activities of daily living. Studies conducted on MCI have introduced new concepts regarding the possible distinctions between normal and pathologic aging of the brain. Neuroimaging and genetic testing have aided in the identification of individuals at increased risk for dementia. The measurement of change in cognitive and functional status in MCI remains challenging, because it requires instruments that are more sensitive and specific than those considered adequate for research in dementia. The authors provide an overview of the many methods that have been used to study MCI and directions that may help achieve greater uniformity in methodology. Considerable heterogeneity exists in research methodology used to study the epidemiology, thresholds for cognitive and functional impairment, rate of progression, risk factors, and defining subtypes of MCI. This article emphasizes the need for uniformity in the use of 1) appropriate and sensitive neuropsychological and functional measures to diagnose MCI, 2) reliable methods to determine progression or improvement of cognitive impairment, and 3) instruments in epidemiologic studies to establish population estimates for diverse ethnic and cultural groups. Greater consensus is needed to standardize definitions and research methodology for MCI, so as to make future studies more comparable and more useful for designing effective treatment strategies.

MMPI-2 short form: psychometric characteristics in a neuropsychological setting.

A 180-item short form of the MMPI-2 (MMPI-2-180) was recently developed by Dahlstrom and Archer and has been proposed for clinical use under special circumstances. This study investigated the psychometric characteristics of the MMPI-2-180 in order to delineate its strengths, limitations, and appropriate scope of clinical application. Using a neuropsychological referral sample (N = 205), we examined accuracy of the short-form as it pertains to the following (a) the prediction of basic scale scores and profile code types, (b) the identification of high-point scales, and (c) the classification of scores as pathological (T > or = 65) or normal range. The results indicate that the MMPI-2-180 provides an unreliable basis for predicting clinical code types, identifying the high-point scale, or predicting the scores on most of the basic scales. In contrast, scores on the MMPI-2-180 are accurate predictors of whether the full-scale scores fall within the pathological range (T > or = 65). These findings suggest that (a) standard interpretive procedures involving profile configuration should not be used, in most cases, with the 180-item short-form results, (b) properly interpreted, this shortened version provides potentially useful information regarding the probable presence of various problem areas, and (c) this information is very limited when contrasted with that obtained using the complete or abbreviated (i.e., 370 item) version of the MMPI-2.

MMPI-2 scale F(p) and symptom feigning: scale refinement.

The F(p) scale of the MMPI-2 is widely used to help identify exaggeration of psychological problems in psychiatric, forensic, and neuropsychological settings. The scale was constructed by selecting all MMPI-2 items (N = 27) that were endorsed by less than 20% of a sample of VA psychiatric inpatients and 20% of the normative sample used in restandardizing the MMPI-2. Although F(p) is used to measure symptom exaggeration and malingering, 4 of its 27 items load on the Lie (L) scale, which is known to be a measure of defensiveness and symptom underreporting. These four items, which express a denial of occasional anger, irritability, and procrastination, could conceivably measure an uncommon expression of defensiveness. This study used 150 neuropsychological referrals to test the hypotheses that (a) the four L scale items measure defensiveness, not exaggeration, and (b) the elimination of these items improves the utility of F(p) in assessing symptom exaggeration. The results indicate that the four L scale items are associated with defensiveness, not with symptom exaggeration. One third of the patients had an average T-score artifact of 9.5 points on F(p) as a result of endorsing these L scale items, with a range of 0T to 21T. Using the K scale as a criterion for level of problem disclosure, a shortened version of F(p) (omitting the four L scale items) was superior to F(p) as a measure of symptom exaggeration (r = -.46 vs. -.36, r2 = 21% vs. 13% of the variance). The implications for clinical practice are discussed.

Familial Creutzfeldt-Jakob disease: a neuropsychological case study.

The spectrum of neuropsychological features of familial Creutzfeldt-Jakob disease (CJD) have seldom been reported, possibly because of (a) the rarity of this hereditary form of prion disease; (b) frequent delays in diagnosis, and; (c) the typically rapid demise of the patient, which affords little opportunity for comprehensive testing or serial analysis. Here we describe the neurobehavioral characteristics of a 48-year-old right-handed male (JD) who presented with complaints of poor depth perception, unsteady gait, and unusual sensory experiences in his face and neck. JD was followed serially over the final 4 months of his 5-month illness. Immediately following hospital admission, he underwent a neuropsychological evaluation that revealed moderate to severe impairment of delayed (30-minute) verbal memory, tactual performance in his right hand, and word-finding ability. In contrast, other abilities that are commonly classified within the verbal, visuospatial, and memory domains showed minimal or no compromise. Parallel studies of electroencephalographic activity revealed diffuse slowing and, later, 1-Hz rhythmical discharges over the left hemisphere, and mild prominence of the lateral ventricles and cerebral sulci on magnetic resonance imaging. Autopsy revealed spongiform changes and reactive astrocytosis, and genetic testing demonstrated a codon 200 mutation in the prion protein gene. These findings indicate that CJD can result in clinical manifestations compatible with multifocal asymmetric cerebral involvement before more diffuse neurodegeneration ensues, providing a strong impetus for the study of additional cases. This long-term understanding can help to determine whether the multiple loci of clinical involvement are specified by genetic or epigenetic factors, or both.

Diffuse Lewy body disease: clinical, pathological, and neuropsychological review.

The pathophysiological etiologies and clinical presentations of neurodegenerative dementias have been found to be complex and heterogeneous. Recently, Lewy body inclusions have been identified as an etiological factor in 20-34% of autopsied dementia cases. The term diffuse Lewy body disease (DLBD) is generally accepted as the diagnostic term representative of this currently under-reported and under-recognized disease. This article reviews the literature on the clinical, pathological, and neuropsychological features of this disorder. Differential diagnostic issues are discussed as well as current pharmacological treatment. Nine confirmed cases of DLBD are presented to demonstrate the various features of this disorder. The diagnostic implications of neuropsychological examination results are discussed in relation to other common dementing neurologic diseases.

Frontotemporal dementia and Alzheimer's disease: differential diagnosis.

This report addresses the clinical differentiation of Alzheimer's disease (AD) from frontotemporal dementia (FTD), including Pick's disease. The accuracy of a clinical diagnosis of a dementing disorder is determined in part by the prior probability (base rates) of the disorder, which predicts an overwhelming likelihood of a diagnosis of AD, because the prevalence of AD is much greater than FTD. The clinical features of the disorder also determine the accuracy of diagnosis. Recent studies have reported an improvement in the differential diagnosis of FTD, utilizing the Lund-Manchester criteria. Patients with FTD typically have early noncognitive behavioral changes with relatively spared cognition, frontal atrophy and enlargement of the Sylvian fissures on CT and MRI scans, and frontal-temporal deficits on SPECT or PET scans. In contrast, AD patients have early cognitive changes with relatively preserved personality and behavior, hippocampal and medial-temporal lobe atrophy on CT or MRI scans, and parietotemporal SPECT or PET deficits.

Sensitivity and specificity of three clinical criteria for dementia with Lewy bodies in an autopsy-verified sample.

OBJECTIVE: To evaluate the sensitivity and specificity of the clinical features of three published diagnostic criteria for diffuse Lewy body disease (DLBD) using autopsy-confirmed Alzheimer's (AD), DLBD and AD+DLBD (mixed) dementia cases. DESIGN: Retrospective chart review of an autopsy series of 56 patients selected from the State of Florida Brain Bank on the basis of a pathological diagnosis of either pure AD, DLBD (pure and common forms) or AD+DLBD (mixed) dementia. Clinical features were assessed by three raters blind to the pathological diagnosis. RESULTS: The existing criteria for a clinical diagnosis of DLBD were highly specific (90-100%) but not very sensitive (49-63%) in the differential diagnosis of DLBD versus AD; sensitivity did improve (61-74%) when mixed AD+DLBD cases were eliminated. Clinical features that occur more frequently in DLBD than in AD were unspecified hallucinations, unspecified EPS, fluctuating course and rapid progression. Post-hoc analysis also indicated that hallucinations and EPS were more common early in the disease course of DLBD than in AD. Empirically derived criteria, formulated using the most prevalent clinical features, demonstrated sensitivity values of 57-96% for pure forms and 43-91% for mixed forms. CONCLUSIONS: This study demonstrated that additional improvements in the established criteria for DLBD are needed. Our empirically derived criteria enhanced the distinction of DLBD from AD while allowing the clinician the choice of maximizing sensitivity with acceptable specificity, and vice versa.