Deleterious versus neuroprotective effect of metabolic inhibition after traumatic spinal cord injury

STUDY DESIGN

This work is an experimental and prospective study in adult, female, Long-Evans rats.

OBJECTIVES

The aim of this study was to probe the effect of metabolic inhibition after an acute traumatic spinal cord injury (TSCI) using a standardized contusion model (NYU impactor) to know whether the metabolic inhibition is a 'secondary mechanism of injury' or a mechanism of protection.

SETTING

All experimental procedures were carried out in the Mexico City.

METHODS

Animals were divided into five groups: one sham and four with TSCI, including no treatment, rotenone (inhibitor of mitochondrial complex I), sodium azide (inhibitor of mitochondrial complex IV) and pyrophosphate of thiamine or non-degradable cocarboxylase as a metabolic reactivator.

RESULTS

After TSCI, the metabolic inhibition with sodium azide treatment diminished the lipid peroxidation process (malondialdehyde levels by spectrophotometric procedures) and the damage to the spinal cord tissue (morphometric analysis), and increased the activity of creatine kinase and lactate dehydrogenase enzymes (P<0.05) (measured by spectrophotometric procedures 24 h after TSCI as well as after the functional recovery of the hind limb (evaluated weekly for 2 months by the BBB (Basso, Beattie and Bresnahan) scale)) when compared with the TSCI group without treatment.

CONCLUSION

The results show that the partial and transitory inhibition of the aerobic metabolism after an acute TSCI could be a self-protection mechanism instead of being a 'secondary mechanism of injury'.

Management of neuroendocrine tumors: a meeting of experts from Latin America

A panel of experts from Latin America convened in Brazil, in May of 2007, for consensus recommendations regarding the management of neuroendocrine tumors (NETs) of the gastrointestinal tract and pancreas. The recently introduced World Health Organization classification of NETs represents a step forward, but the former classification of carcinoids into foregut, midgut and hindgut is still likely to be useful in the near future. Macroscopic description of the tumor should be followed by light microscopic examination and immunohistochemical staining, whereas other techniques might not be widely available in Latin America. Surgery remains the mainstay of treatment for patients with potentially curable tumors, and adequate selection is paramount in order to optimize treatment results. Regarding systemic therapy, patients with well-differentiated tumors or islet-cell carcinomas may be categorized as having indolent disease, while patients with poorly differentiated, anaplastic, and small-cell carcinomas, or with atypical carcinoids, may be approached initially as having aggressive disease. Somatostatin analogues play a cytostatic role in indolent tumors, and chemotherapy may play a role against other, more aggressive NETs. Obviously, there is an urgent need for novel therapies that are effective against NETs.

The mini-mental state examination: age and education distribution for a Latin American population

The Mini Mental State Examination (MMSE) is used widely internationally. Data on population age and gender distribution of MMSE scores outside of the US is rare. The Composite International Diagnostic Interview (CIDI), which incorporates the MMSE, was administered to a household sample of 2978 individuals age 15 and older in Chile. DSM-III-R lifetime prevalence rates were estimated. The average MMSE score ranged from 16-29 depending on the level of educational attainment. Sociodemographic variables, including age marital status, urban-rural and income, impacted MMSE scores. When the MMSE scores were controlled for sociodemographic variables, those with any psychiatric disorder had significantly lower scores; however, specific diagnoses did not affect MMSE scores.

Targeting of lanthanide(III) chelates of DOTA-type glycoconjugates to the hepatic asyaloglycoprotein receptor: cell internalization and animal imaging studies

The characterization of a new class of hydrophilic liver-targeted agents for gamma-scintigraphy and MRI, consisting, respectively, of [(153)Sm](3+) or Gd(3+) complexes of DOTA monoamide or bisamide linked glycoconjugates (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), is reported. In vitro studies show high uptake of radiolabeled [(153)Sm]-DOTAGal(2) by the human hepatocyte carcinoma cell line Hep G2 containing the asialoglycoprotein receptor (ASGP-R), which is decreased to less than 50% by the presence of its high-affinity ligand asialofetuin (ASF). In vivo biodistribution, gamma-imaging and pharmacokinetic studies on Wistar rats using the [(153)Sm](3+)-labeled glycoconjugates show a high uptake in the receptor-rich organ liver of the radiolabeled compounds containing terminal galactosyl groups, but very little uptake for those compounds with terminal glycosyl groups. Blocking the receptor in vivo reduced liver uptake by 90%, strongly suggesting that the liver uptake of these compounds is mediated by their binding to the asyaloglycoprotein receptor (ASGP-R). This study also demonstrated that the valency increase improves the targeting capability of the glycoconjugates, which is also affected by their topology. However despite the specific liver uptake of the radiolabeled galactose-bearing multivalent compounds, the animal MRI assessment of the corresponding Gd(3+) chelates shows liver-to-kidney contrast effects which are not significantly better than those shown by GdDTPA. This probably results from the quick wash-out from the liver of these highly hydrophilic complexes, before they can be sufficiently concentrated within the hepatocytes via receptor-mediated endocytosis.

Functional, cellular and molecular aspects of skeletal muscle recovery after injury induced by snake venom from Notechis scutatus scutatus

We have analysed the rate and ultimate extent of muscle functional recovery after snake venom-induced myotoxicity, as well as the relationships between functional, biochemical and structural indices of recovery. We also compared the effects of various injuries leading to muscle necrosis, loss of innervation/vasculature and/or precursors of muscle cells (pmc). We found that several parameters of rat soleus muscle such as maximal isometric force, slow myosin heavy chain, and citrate synthase, were fully and rapidly restored within 6 weeks after treatment with snake Notechis scutatus venom (im, 2 microg/muscle). In contrast, some muscle contractile properties (degree of tetanic fusion, fatigue resistance...) were not fully recovered even by 12 weeks after venom treatment. However, when compared to other injuries, recovery 3 weeks after venom treatment, was better than that observed after severing the terminal nerve and accompanying vessels and after cryodamage known to kill pmc. In conclusion, our studies demonstrate that-contrary to what is commonly believed -- muscle treated by myotoxic agent does not recover rapidly and fully. However, the degree or rate of muscle recovery after snake venom treatment was much better when compared to other types of injury. In addition, histological and biochemical parameters cannot be used as such to easily predict functional recovery following injury.

Polarization Observations with the Cosmic Background Imager

Polarization observations of the cosmic microwave background with the Cosmic Background Imager from September 2002 to May 2004 provide a significant detection of the E-mode polarization and reveal an angular power spectrum of polarized emission showing peaks and valleys that are shifted in phase by half a cycle relative to those of the total intensity spectrum. This key agreement between the phase of the observed polarization spectrum and that predicted on the basis of the total intensity spectrum provides support for the standard model of cosmology, in which dark matter and dark energy are the dominant constituents, the geometry is close to flat, and primordial density fluctuations are predominantly adiabatic with a matter power spectrum commensurate with inflationary cosmological models.

[Pulmonary Artery Sarcoma - diagnostic and treatment difficulties]

Primary Pulmonary Artery Sarcoma is a rare entity, which shares some clinical features with Thromboembolic Pulmonary Disease (TEPD), complicating differential diagnosis. The authors report a Clinical Case of a Primary Pulmonary Artery Sarcoma in a 59 years old man, admitted with a history of dyspnoea on exertion, chest pain and general symptoms. Chest X-ray, Computed Tomography Scan, Angiographies and Magnetic Resonance Imaging suggested TEPD. Blood Analysis performed before anticoagulation therapy: Lupus Anticoagulant-and Ig M Anticardiolipin +. Our presumptive initial diagnosis was TEPD in a patient with a hypercoagulable state. Intravenous heparin was started, with some clinical improvement but 2 months later he was readmitted, due to clinical and radiological deterioration. Pulmonary Thromboendarterectomy was considered but a right pneumonectomy was necessary because of bleeding. He died of ARDS in a single lung in the 7th day after surgery. Pathology revealed pulmonary artery sarcoma with pulmonary and pleural metastases.

Broncho-alveolar inflammation in cork worker's asthma

Suberosis is an occupational lung disease of cork workers associated with repeated exposure to mouldy cork dust in the cork industry, usually presenting as an interstitial lung disorder (Extrinsic Allergic Alveolitis). However, Occupational Asthma can also be associated with cork dust exposure and demonstrated by serial peak expiratory flow changes.

AIM

To investigate broncho-alveolar inflammation in patients with cork work-related occupational asthma, evaluated by Broncho-alveolar fluid cellular profiles and serial peak expiratory flow (PEF) rates monitoring.

RESULTS

We studied 14 patients with respiratory symptoms associated with occupational exposure in the cork industry. Positive PEF monitoring occurred in 7 cases (Occupational Asthma-OA), and in 7 (Non-occupational asthmatics-NOA) PEF records were negative. There were no differences in age, lung function (FEV1%, RV%), bronchial hyperresponsiveness, years of exposure, and atopy between the two patients groups. However, patients with work-related asthma had higher BAL eosinophil counts than NOA (1.9 +/- 2.6% versus 0.2 +/- 0.3%; p < 0.05, Wilcoxon test).

CONCLUSIONS

Cork worker's asthma, demonstrated by work related changes in serial PEF recordings, is associated with eosinophilic lung inflammation as described in other forms of occupational asthma.

Prevention of dexamethasone-induced lymphocytic apoptosis in the intestine and in Peyer patches by enteral nutrition

BACKGROUND

Apoptosis is a programmed cell death, genetically controlled, that can be activated by physiological and pathophysiological events and by the administration of several drugs, including the exogenous administration of corticosteroids. The aim of this study was to develop a rat model of intestinal lymphocytic apoptosis induced by dexamethasone to determine if apoptosis could be prevented by enteral or parenteral nutrition.

METHODS

Male Sprague-Dawley rats were used. On day 0, the right internal jugular vein was catheterized for parenteral nutrition, and a silicone tube was inserted into the duodenum for enteral feeding. Animals (n = 6/group) were randomly assigned to one of the following 3 feeding regimens: an immune-enhancing enteral diet; its placebo (the same formula without immunonutrients); and isocaloric isonitrogenous parenteral nutrition. On the seventh day, 200 microg of dexamethasone or vehicle were administered by i.v. bolus, and the diets were continued for 1 more day. Intestinal Peyer patches and thymic lymphocytic apoptosis were determined both by flow-cytometry and immunohistochemistry.

RESULTS

A single dexamethasone dose (200 microg/rat) administered to surgically treated rats fasted for 18 hours, 24 hours later, caused massive intestinal and Peyer patches lymphocytic apoptosis (96 +/- 2% and 85 +/- 5%, respectively; p < .0001 versus vehicle in both kinds of tissue). Lymphocytic apoptosis was reduced to almost indetectable levels in intestinal and lamina propia lymphocytes (from 96 +/- 2% to <0.6%; p < .0001). Peyer patches lymphocytic apoptosis was reduced as well (from 85 +/- 5% to 15 +/- 7.1%; p < .001) in animals prefed the 2 enteral nutrition formulas. Those prefed parenteral nutrition only showed a partial decrease of lymphocytic apoptosis in the intestine (from 96 +/- 2% to 53 +/- 23%; p < .001). Nutrition had no effect on the dexamethasone-induced thymus involution.

CONCLUSIONS

Enteral nutrition prevents intestinal intraepithelial and lamina propia lymphocytic apoptosis due to dexamethasone. These findings support the use of early enteral nutrition in critically ill patients treated with corticosteroids.

Experimental treatment of chronic Trypanosoma cruzi infection in mice with 2-n-propylquinoline

It was reported previously that 2-n-propylquinoline was active against the epimastigote form of Trypanosoma cruzi. The effects of oral treatments with benznidazole and 2-n-propylquinoline were evaluated in Balb/c mice infected with T. cruzi chronically. The reference drug and 2-n-propylquinoline were administered 60 days post-infection for 30 days at 25 mg/mL. At 35 days post-treatment, the serological tests (ELISA) of the 2-n- propylquinoline-treated mice were significantly different from the controls (p = 0.01) and the benznidazole-treated mice (p = 0.03), while this was not the case at 85 days post-treatment. These results are encouraging for continuing the investigation of other analogues of 2-n-propylquinoline in experimental chronic Chagas' disease.

Complications of colonic diverticular disease. Comparative study of two series

OBJECTIVE

To compare the form of presentation and management of the disease in two surgical units covering geographically different populations.

DESIGN

Observational retrospective study.

PATIENTS AND METHOD

203 cases from the 2nd Chair of Surgery of the Hospital Universitario de Clínicas de Asunción, Paraguay and 150 cases from the Hospital Universitario de Lleida, Spain. We analyzed the cause of admission, medical history, treatment and post-operative morbidity and mortality.

RESULTS

Paraguay series: average age: 53 years (range 34-84) for men and 62 years (range 36-92) for women. Fifty-five per cent were hospitalized because of hemorrhagic complications and 45% because of acute diverticulitis. Medical treatment was provided in 109 cases and surgery in 110, 72 of which were emergencies and 38 elective procedures (p < 0.05). Morbidity was 31.8% (40.2% in emergencies and 16% in elective procedures, p < 0.05) and mortality was 15.5% (20.2% in emergencies and 2.6% in elective procedures, p < 0.003). LLEIDA SERIES: Average age: 65.5 years (range 38-85, p < 0.01) for men and 71.4 years (range 30-93, p < 0.01) for women. Eighty-six per cent were hospitalized because of acute diverticulitis and 10.7% because of acute hemorrhage (p < 0.001). Sixteen per cent have had previous attacks (p < 0.001). Medical treatment was provided to 111 patients and surgery to 39 (p < 0.001), 33 of which were emergencies and 6 elective procedures (p < 0.04). Morbidity was 41% and mortality 12.8% (5 cases), all of which were emergencies. The surgical technique was similar in both groups: resection with primary anastomosis in elective procedures and Hartmann's procedure in most emergencies, with a rate of immediate anastomosis of 33 and 21%, respectively.

CONCLUSIONS

Factors related to nutrition and quality of life may influence the development of diverticular disease. Emergency surgery should be prevented. Surgeons must adapt their surgical approach to the socioeconomic and cultural medium of the population.

Bridges and Barriers: Educational Mobility of Hispanic Nurses

The lack of data on the educational mobility of the Hispanic nurse presents major barriers in designing effective strategies to diversify the nursing work force. However, such data are necessary to ensure parity of representation of Hispanics in nursing. The purpose of this project was to identify barriers and bridges to educational mobility experienced by Hispanic nurses. Focus groups were conducted in six sites throughout the country. Separate groups were conducted with Hispanic ADN nurses who had completed their BSN and with BSN nurses who had completed their MSN. Barriers encountered and identified by participants included financial burdens, institutional barriers, perceived discrimination by faculty and peers, and cultural values such as the importance of the family and prescribed gender roles. Conversely, bridges to completing degree requirements included family, peers, and faculty. Recommendations to facilitate educational mobility of Hispanic nurses are provided.

Flow cytometry of cell proliferation through the incorporation of bromodeoxyuridine as an index of growth rate in the water flea, Daphnia magna (Crustacea, Cladocera)

BACKGROUND

In this paper, we used a small crustacean as a model to develop a method for quantifying growth rates through the measurement of a cell proliferation marker. This was done in order to study the feasibility of this assay for estimating zooplankton production in the ocean. Flow cytometry immunodetection of bromodeoxyuridine (BrdU) was performed to detect and quantify the cycling nuclei of Daphnia magna.

METHODS

A combination of mechanical dissociation and cell enucleation procedures proved to be the most convenient method for preparing nuclear suspensions from whole organisms. Up to three populations of nuclei with different ploidy were observed. The relative abundance of these nuclear populations changed with the size of the flea.

RESULTS

The staining technique has been optimized. The time and concentration for the maximum detection of BrdU-labeled nuclei were 3 h at 300 microM BrdU. Whole organisms can be frozen (-20 degrees C) after incubation with no changes in the final results. The method was used in different physiological conditions under controlled food and temperature in order to test the inverse relationship between physiological rates and size of organisms at several developmental stages. The quantification of BrdU-labeled nuclei in 1-6 day-old larvae showed the highest labeling index, with a mean of 95 +/- 1% (n = 22). In contrast, young animals (0.8-1.2 mm) had 25 +/- 4% (n =16, P < 0.001) and adults (>1.4mm) had 14 +/- 3% (n = 4, P < 0.001). The results obtained show an expected tendency, suggesting that a direct relationship exists between the labeling index and the instantaneous growth rate.

CONCLUSIONS

Certain features of our method, such as the short times required for labeling and the possibility of preserving the samples during field experiments and under different conditions (including natural concentrations and types of food), are advantageous to the study of processes governing energy fluxes in pelagic ecosystems.

Monitoring of peak expiratory flow rates in cork workers' occupational asthma

Suberosis is an occupational lung disorder of cork industry workers usually presenting as an extrinsic allergic alveolitis, but airway involvement in some cases makes the diagnostic approach complex. We assessed peak expiratory flow rates (PEF) in 17 cork workers with asthma symptoms that worsened at work, comparing three methods of PEF graph analysis. Complete agreement (three observers) was found in 12 of 17 cases (70.6%) with the visual inspection of mean daily values and in 11 of 17 cases (64.7%) with the minimum, maximum, and mean daily values (without any consensus in two cases). According to the mean PEF graph, there were eight positive readings (47%), five negative readings (29%), and four dubious readings (24%); with the other graphic analysis, two of the dubious cases were reclassified as negative. When we analyzed daily variability >20%, we found only three positive results, one of which was in absolute disagreement with the visual analysis. Our results suggest that it is possible to demonstrate occupational asthma in cork work exposure. The visual inspection of PEF monitoring shows a greater number of positive results than the index of daily variability; however, the latter may help to sort out dubious cases.

[Arterial blood pressure behavior during the administration of intravenous streptokinase, in patients with acute myocardial infarction]

OBJECTIVE

To evaluate the effect on blood pressure (BP) of intravenous (i.v.) streptokinase (SK) in patients (PTS) with acute myocardial infarction (AMI).

DESIGN

Retrospective study with analysis of BP registers ten minutes before and during SK infusion.

SETTING

PTS admitted to the Coronary Care Unit (CCU) of Santo António Hospital, Oporto.

PATIENTS

Thirty-eight male PTS, average ages of 54, ranging from 38 to 67, AMI confirmed, and criteria to thrombolytic therapy. One patient was excluded on account of persistent hypotension since admission.

MATERIAL AND METHODS

I.v. infusion of 1.500.000 U of SK over 60 minutes, preceded by 200 mg i.v. of prednisolone. BP and heart rate (HR) were evaluated with Datascope Accutorr 1A set. The lowest value of the systolic BP (SBP) recorded ten minutes before SK infusion was considered the baseline value. We valued the reduction of SBP above 15%, defining its fall as the difference between the baseline value and the minimum value of SBP recorded during the infusion. Hypertension was defined to SBP values below 90 mmHg.

MAIN RESULTS

The fall was 40.4 +/- 22.1 mmHg (range 9 to 102, having been recorded the minimum value at 22.9 +/- 10.9 minutes. It was accompanied by diastolic BP (DBP) fall of 30.6 +/- 18.9 mmHg (range -2 to 76) and by a HR increasing from 76.2 +/- 13.7 beats/min. to 80.8 +/- 14.1 beats/min. (p < 0.01). In 86% of the PTS this fall was transient, lasting 8.9 +/- 6.3 minutes, and was corrected by slowing or stopping the infusion for a few minutes and placing the patient in Trendelenburg position. Two PTS needed sympaticomimetic amines because of persistent BP reduction despite the previous measures. 92% of the PTS had a SBP fall higher than 15% in relation to the baseline value. The SBP was kept over 90 mmHg in 20 PTS (54%); hypotension was recorded in the remaining 14 PTS (38%), and in 10 (27%) of these the SBP fell below 80 mmHg. We couldn't prove that the infarction and the extension of the ischemic lesion had influenced this BP fall.

CONCLUSIONS

The BP reduction during treatment with high doses of SK deserves some attention because, although transient and easily reversible, it is frequent and sometimes significative. It demands then careful monitoring in order to avoid the hypoperfusion to the ischemic myocardium, that could jeopardize the potential benefits of reperfusion in the reduction of infarction area, the main objective of the thrombolytic treatment.

Transesophageal echocardiography in the assessment of patients presenting with ischemic cerebral events without previous evidence of a cardiac source of emboli

Transesophageal echocardiography (TEE) is accepted as a valuable tool in the evaluation of ischemic stroke patients, particularly in the young and in cases of unknown cause. However, the real clinical impact of additional TEE data remains to be defined.

PURPOSE

The aim of this study was to present our experience with TEE in ischemic stroke patients without previous evidence of a cardiac source of emboli.

METHODS

From March 1991 to June 2000 we studied 172 patients (80 males, 92 females, mean age 43 +/- 12 years presenting with a transient ischemic attack or a recent cerebral infarction who had no previous evidence by clinical assessment, electrocardiogram and transthoracic echocardiography of a cardiac of emboli source. The population was divided into two groups: Group A--age < or = 45 years, n = 101 (43 males, 58 females, mean age 34 +/- 7 years) and Group B--age > 45 years, n = 71 (36 males, 35 females, mean age 54 +/- 7 years). Information was gathered from clinical records. In every case TEE included Doppler color flow imaging and multiple contrast injections (agitated saline) with and without Valsalva maneuver.

RESULTS

A potential cardiac of emboli source was found in 29% of the patients, with a higher prevalence in the older group (group A--25%, Group B--35%, ns). Atrial septal abnormalities accounted for most of the detected findings (23 patent foramen ovale, 17 atrial septal aneurysms and two atrial septal defects, representing altogether 71% of the findings). The other detected anomalies were distributed as follows: aortic plaques--six, mitral valve prolapse--five vegetations--four, thrombus in left atrial appendage--two. Only six patients (3.5%) had abnormalities which in themselves determined a specific approach, which were found mostly in the older group (Group A--two vegetations; Group B--two vegetations, two thrombi).

CONCLUSIONS

TEE identified additional findings with possible embolic potential in a considerable number of cases, the majority of which were of a debatable cause-effect relation. A higher diagnostic yield and clinical relevance was found in older patients, which argues against age being used as a selective criterion for it. Our experience suggests that routine TEE in this setting is of questionable value and has little impact on clinical management, for which reason TEE referral should be decided on an individual patient basis.

Evaluation of vegetal extracts as biological herbi- and pesticides for their use in Cuban agriculture

The idea of an interuniversity project between the Universidad Central de Las Villas, Cuba and the University of Ghent, Belgium was conceived in order to improve the quality of the Cuban agriculture and to stimulate its independence from foreign chemical farm inputs, starting with an applied ethnobotanical investigation as basis for the development of sustainable agricultural practices. The project consists of three parts. The first, ethnobotanical part, subtends the two subsequent stages, i.e. the phytochemical and pharmacological stages. After ethnobotanical inventarization of plants with a possible phytotoxic or pesticide effect, these will be collected and taxonomically defined. Fresh vegetal material will be dried and ground, and this first crude extract (polar or apolar) will be tested for its activity in in vitro biological tests. When results are positive (presence of activity), this crude extract will be tested in vivo, which could lead to immediate application in agriculture (short-term strategy). The long-term strategy will lead to the identification of chemical substances, responsible for the activity of the crude extract. As highly sophisticated apparatus is needed for this last step (i.e. identification of chemical compounds), this will be performed by the Department of Organic Chemistry, Faculty of Agricultural and Applied Biological Sciences of the University of Ghent. The project has started in September 2000. Apart from all the (complicated) administrative steps to be undertaken for its successful execution, the ethnobotanical and phytochemical parts have already started. Ethnobotanical data were gathered in view of recollection of "traditional botanical knowledge", considering three main approaches: the use of plants in medicine, in Cuban religion (the famous "santería") and the use of allelopathic plants in agriculture. Use of medicinal and religious plants is ubiquitous in Cuba. The concept of allelopathy, however, is much less known and applied. At this moment, and after preliminary screening and gathering of field data, in vitro germination tests are running, trying out extracts of tobacco (Nicotiana tabacum), banana (Musa spp.), sunflower (Helianthus annuus), Simarouba glauca and S. laevis (syn. Quassia, fam. Simaroubaceae).