Stent angioplasty for treatment of canine valvular pulmonic stenosis.

Four dogs presented for evaluation and treatment of severe pulmonic valve stenosis and underwent stenting of the pulmonic valve annulus using bare-metal balloon-expandable stents. All dogs survived the procedure with immediate reduction of the transpulmonary valve pressure gradient and increase in activity levels. One dog had a stent fracture and migration 1 month after the intervention. This dog underwent a second procedure, in which multiple stents were used to alleviate the obstruction. The stents that were placed at the level of the right ventricular outflow tract fractured within 1 month of the procedure, and the patient died when a third (surgical) approach was attempted. The other three dogs remain alive 54, 42, and 29 months after the procedure. Stent angioplasty may be a viable option for dogs with valvular pulmonic stenosis in which routine balloon valvuloplasty does not provide a successful outcome. Aggressive attempts to diminish RVOT dynamic obstruction with high-dose beta blockade and avoiding deployment of the stent within the RVOT are recommended to prevent stent fracture and migration.

Expression of bone-related proteins in vascular calcification and its serum correlations with coronary artery calcification score.

Since vascular calcification is considered a process regulated similar to that of bone tissue mineralization, we investigated the participation of bone formation proteins. We analyzed the correlation of serum circulating bone markers, osteoprotegerin (OPG) and receptor activator of nuclear factor ĸB ligand (RANKL) in chronic kidney disease (CKD) patients, to coronary artery calcification score. We also considered the effect of inorganic phosphate on pro- and anti-calcifying tissue factors. We confirmed that circulating OPG is an independent calcium score predictor with its high serum concentration favoring high coronary artery calcification. In tissue samples of non-diseased human renal arteries, the expression of OPG and receptor activator of nuclear factor ĸB (RANK) was positive, while expression of RANKL was absent. In atherosclerotic specimens and arteries with medial calcification, the most upregulated was expression of bone morphogenetic proteins, BMP-2 and BMP-7, as well as expression of RANK and RANKL. In the diseased arteries, OPG expression was present only in areas where bone structures were formed. In atherosclerotic and medial calcification arteries, loss of alpha-smooth muscle actin (α-SMA) expression was observed. These data suggest a possible regulatory role of the examined proteins, especially OPG and RANKL, in vascular calcification, as well as their possible clinical significance as circulating predictors of vascular calcification.

Effect of radial shock wave therapy on long bone fracture repair.

Nowadays, various diseases of the locomotor system are treated by extracorporeal shock wave therapy (ESWT) for instance: acute fracture and pseudoarthrosis, nonunion, chronic tendinitis. Unfocused (radial) pressure wave therapy (RPWT) primarily affects superficial tissues, so justifiability of its medicinal employment is uncertain. We aimed to observe time sequence of the long bone fracture healing using RPWT. Forty-eight female Wistar rats were divided into an RPWT group (n=36) and a control group (n=12). The RPWT group had the largest cross-sectional area (CSA) of the bone trabeculae compared to controls. Post-hoc analyses revealed the largest cross-sectional area (CSA) of the bone trabeculae (1.7 mm2) and the smallest CSA of the cartilage (0.04 mm2) of the RPWT group on the 22nd day. Conclusively, long bone fracture repair is enhanced by RPWT, suggesting that it strongly stimulates the processes of callus ossification.

VEGF-A expression in soft tissues repaired by shockwave therapy: differences between modalities.

Shockwave therapy has found its place in the medical treatment of various diseases of the locomotor system such as acute fracture, nonunion, chronic tendinitis and pseudarthrosis. Focused shock waves enable maximum energy in the therapeutic zone, and depth of penetration can be adjusted. Radial shockwave therapy primarily affects superficial tissues, so its application in medicine is doubtful. Our study aimed to assess long bone fracture healing in regard to soft tissues. For this investigation, 84 female Wistar rats were divided into a focused shockwave group (n=36), a radial shockwave group (n=36) and a control group (n=12). Conclusively, long bone fracture repair was enhanced in the shockwave groups. Comparison between focused shock waves and radial shock waves suggested that this latter strongly stimulated the processes of the healing, as 75% of vascular spaces were VEGF-A positive on the 5th day of bone healing, and 85% on the 22nd day of healing.

Medicamentous thrombolysis disguises pulmonary thromboembolism as a cause of death.

We report the case of a 31-year-old female who was admitted to the emergency department with symptoms of cardiac arrest and ultimately died in spite of enormous resuscitation efforts. During resuscitation, pulmonary embolism was considered as a possible non-cardiac cause of cardiac arrest, and following its extremely unfavorable prognosis, the fatal outcome was not so surprising. However, since acute pulmonary emboli obstructing blood flow to a lobe or multiple lung segments was suspected, alteplase was indicated and administered. At the autopsy, no venous thrombosis in the vena cava, pelvic veins, or any of the lower extremity veins was documented; conversely, nor were specific signs of pulmonary thromboembolism (PTE) found macroscopically, until this was confirmed by histopathological staining which is not used as a routine diagnostic tool in forensic medicine. In this study, we conclude that PTE is generally overlooked as the principal diagnosis and the cause of death. Rightful postmortem diagnosis could lead to increased vigilance and a change in management in many of such cases, which could result in improved survival. Motivated by providing better awareness of PTE, this study aimed to illustrate unrecognized PTE and pathological findings that were masked by thrombolytic drugs.

Investigation of an N-Terminal Prohormone of Brain Natriuretic Peptide Point-of-Care ELISA in Clinically Normal Cats and Cats With Cardiac Disease.

BACKGROUND: N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentrations may be increased in cats with various cardiac disorders. The point-of-care (POC) ELISA assay uses the same biologic reagents as the quantitative NT-proBNP ELISA. Previous studies have evaluated the sensitivity and specificity of the POC ELISA in cats with cardiac disease. OBJECTIVES: To prospectively evaluate the diagnostic utility of the POC ELISA in a select population of cats. ANIMALS: Thirty-eight client-owned cats presented to the University of Florida Cardiology Service for cardiac evaluation. Fifteen apparently healthy cats recruited as part of another study. METHODS: Physical examination and echocardiography were performed in all cats. The POC ELISA was assessed visually as either positive or negative by a reader blinded to the echocardiographic findings, and results were analyzed relative to quantitative assay results. RESULTS: Twenty-six cats were diagnosed with underlying cardiac disease, and 27 cats were considered free of cardiac disease. Cats with cardiac disease included: 21 with hypertrophic cardiomyopathy, 2 with unclassified cardiomyopathy, 2 with restrictive cardiomyopathy, and 1 with 3rd degree atrioventricular (AV) block. The POC ELISA differentiated cats with cardiac disease with a sensitivity of 65.4% and specificity of 100%. CONCLUSIONS AND CLINICAL IMPORTANCE: The POC NT-proBNP ELISA performed moderately well in a selected population of cats. A negative test result cannot exclude the presence of underlying cardiac disease, and a positive test result indicates that cardiac disease likely is present, but further diagnostic investigation would be indicated for a definitive diagnosis.

Morbilidad respiratoria en prematuros tardíos y término tempranos / Respiratory morbidity in late preterm and early term infant

INTRODUCCIÓN: Los Recién Nacidos prematuros tardíos (RNPTT) y los Recién Nacidos de Término Temprano (RNTt) son considerados una población de riesgo, con altos índices de ingreso hospitalario y morbimortalidad, mayor cantidad de días de internación y altas tasas de reingreso hospitalario en comparación a los Recién Nacidos de Término Tardío (RNTT). El Síndrome de distrés respiratorio es uno de los principales diagnósticos al ingreso, requiriendo distintos modos de soporte respiratorio, por lo tanto, requieren de cuidados especiales en unidades de media o alta complejidad, significando así un importante costo en salud. OBJETIVOS: Comparar la frecuencia en que se presenta la morbilidad respiratoria (MR) entre RNPTT y en RNTt Vs Recién Nacido a Termino Tardío (RNTT). Establecer factores asociados a MR. Describir los distintos modos de soporte respiratorio utilizados. PACIENTES Y MÉTODOS: Se incluyeron a todos los RNPTT (34 a 36 SEG), y RNTt (37 a 38 SEG) y se compararon con todos los pacientes RNTT (39 a 41 SEG) durante los años 2011 a 2015. Se excluyó a pacientes con malformación o síndrome genético, o derivados de otro centro médico. Análisis estadístico: La frecuencia de MR se consignó en porcentajes. La misma se comparó en ambos grupos utilizando la prueba de Chicuadrado y se realizó el cálculo de Odss Ratio. Las variables maternas o neonatales asociadas a MR se compararon entre los pacientes con o sin MR utilizando prueba U de Mann-Whitney para las variables continuas y Chi-cuadrado para variables categóricas. Las variables con un valor de P ≤ 0.1 en el análisis univariado se incluyeron en un modelo multivariado de regresión logística. El soporte terapéutico utilizado fue descripto en porcentajes y comparados mediante prueba de Chicuadrado y evaluados mediante odss ratio. RESULTADOS: Durante el periodo evaluado se analizaron los datos de 10512 pacientes de los cuales 766 (7,8%) fueron RNPTT, 3654 (92,6%) RNTt y 6087 (57,90%) RNTT. La frecuencia de MR en los RNPTT fue de 202 (26,4%), en los RNTt fue de 115 (3,15%) Vs 46 (0,76%) en los RNTT. El Odss ratio para MR entre RNPTT y RNTt comparado con RNTT respectivamente fue: OR 47.03, IC95% 33.7 a 65.53, P 0.0001, OR 4.26, IC95% 3.02 a 6.02, P 0.0001. (Siendo los RNTT el grupo control. Ver tabla). En el análisis multivariado se observaron factores de riesgo asociados a MR: Patología asociada al embarazo (OR 4,248, IC95% 2,918 a 6,184, P 0.0001), el Apgar menor a 7 a los 5 min (OR 15,09, IC95% 4,64 a 49,03, P 0.0001), el nacimiento por cesárea (OR 2,96 IC95% 2,32 a 3,78, P 0.0001), sexo masculino (OR 1,5 IC95% 1,21 a 2,01, 0,001). En la evaluación en toda la población general se observó al Retardo de Crecimiento Intrauterino (RCIU) como factor protector de MR, (OR 0.51, IC95% 0,29 a 0,92, P 0.029). Los datos en relación al soporte de oxígeno se muestran en la Tabla1. CONCLUSION: Los recién nacidos prematuros tardíos y los recién nacido termino temprano presentaron mayor morbilidad respiratoria comparado con los recién nacidos termino tardío. Los factores de riesgo más preponderantes para MR fueron la prematurez, el nacimiento por cesárea, nacer con Apgar menor a 7 a los 5 min y la existencia de patología materna asociada al embarazo. Los RNPTT y RNTT son una población de riesgo (mayor requerimiento de internación, más días de internación, mayor morbilidad respiratoria y mayor soporte de oxigeno), por lo que se deben de adoptar medidas preventivas para lograr disminuir los factores de riesgo que generan el nacimiento prematuro tardío y término temprano y así lograr disminuir los índices de morbi mortalidad y costos en salud que estos implican. (AU)

INTRODUCTION: Late Preterm Newborns (LPN) and Early Term newborns (ETN) are considered to be at risk, because they have high rates of hospital admission, morbidity and mortality, more days of hospitalization, and high rates of hospital readmission compared To Late term Newborns (LTN). Respiratory distress syndrome is one of the major diagnoses on admission, requiring different modes of respiratory support, therefore, require special care in medium or high complexity neonatal units, meaning a significant health cost. OBJETIVES: Compare the frequency of respiratory morbidity (RM) between late preterm and early term infants Vs complete or late term newborns. Establish factors associated with RM. Describe the different modes of oxigen respiratory support used. PATIENTS AND METHODS: All LPN (34-36 SEGs) and ETN (37-38 SEGs) were included and compared to all LTN (39-41 SEGs) during the years 2011 to 2015. Were excluded patients With malformation or genetic syndrome, or derived from another medical center. Statistical analysis: The frequency of RM was recorded in percentages. The same was compared in both groups using the Chi-square test and the Odss Ratio calculation was performed. Maternal or neonatal variables associated with RM were compared between patients with or without RM using Mann-Whitney U test for continuous variables and Chisquare for categorical variables. Variables with a value of P ≤ 0.1 in the univariate analysis were included in a multivariate logistic regression model. The therapeutic support used was described in percentages and compared by chi-square test and evaluated by odss ratio. RESULTS: Data from 10512 patients were analyzed in the evaluation periode, of which 766 (7.8%) were LPN, 3654 (92.6%) ETN and 6087 (57.90%) LTN. The frequency of RM in the LPN was 202 (26.4%), in the ETN it was 115 (3.15%) vs 46 (0.76%) in the LTN, the odss ratio for RM comparing LPN and ETN with LTN respectively was: OR 47.03, 95% CI 33.7 to 65.53, P 0.0001, OR 4.26, IC95% 3.02 to 6.02, P 0.0001 (LTN being the control group. See table). In the multivariate analysis it was observed the risk factors asociated with RM: the pathology associated with pregnancy (OR 4.248, 95% CI 2.918 to 6.184, P 0.0001), Apgar less than 7 at 5 min (OR 15.09, 95% CI 4.64 to 49.03, P 0.0001). Cesarean birth (OR 2.96, IC95% 2.32 a 3.78, P 0.0001) and Male sex (OR 1,5 IC95% 1,21 a 2,01 P 0,001). In the evaluation in the general population, the Intrauterine Growth Retardation (IUGR) was observed as a protective factor of MR, (OR 0.51, 95% CI 0.29 to 0.92, P 0.029). The data in relation to the oxygen support are shown in Table 1. CONCLUSION: Late preterm infants and early term infants presented higher respiratory morbidity compared to late term newborns. The most important risk factors for RM were prematurity, cesarean birth, birth with Apgar less than 7 at 5 minutes and the existence of maternal pathology associated with pregnancy. The LPN and ETN are a population at risk (greater requirement of hospitalization, more days of hospitalization, greater respiratory morbidity and greater support of oxygen), so that preventive actions must be taken to reduce the risk factors who give late preterm and early term birth and thus reduce morbidity rates and health costs that these imply. (AU)

Inhibition of the Biosynthesis of Prostaglandin E2 By Low-Dose Aspirin: Implications for Adenocarcinoma Metastasis.

Meta-analyses have demonstrated that low-dose aspirin reduces the risk of developing adenocarcinoma metastasis, and when colon cancer is detected during aspirin treatment, there is a remarkable 83% reduction in risk of metastasis. As platelets participate in the metastatic process, the antiplatelet action of low-dose aspirin likely contributes to its antimetastatic effect. Cycloxooxygenase-2 (COX-2)-derived prostaglandin E2 (PGE2) also contributes to metastasis, and we addressed the hypothesis that low-dose aspirin also inhibits PGE2 biosynthesis. We show that low-dose aspirin inhibits systemic PGE2 biosynthesis by 45% in healthy volunteers (P < 0.0001). Aspirin is found to be more potent in colon adenocarcinoma cells than in the platelet, and in lung adenocarcinoma cells, its inhibition is equivalent to that in the platelet. Inhibition of COX by aspirin in colon cancer cells is in the context of the metastasis of colon cancer primarily to the liver, the organ exposed to the same high concentrations of aspirin as the platelet. We find that the interaction of activated platelets with lung adenocarcinoma cells upregulates COX-2 expression and PGE2 biosynthesis, and inhibition of platelet COX-1 by aspirin inhibits PGE2 production by the platelet-tumor cell aggregates. In conclusion, low-dose aspirin has a significant effect on extraplatelet cyclooxygenase and potently inhibits COX-2 in lung and colon adenocarcinoma cells. This supports a hypothesis that the remarkable prevention of metastasis from adenocarcinomas, and particularly from colon adenocarcinomas, by low-dose aspirin results from its effect on platelet COX-1 combined with inhibition of PGE2 biosynthesis in metastasizing tumor cells. Cancer Prev Res; 9(11); 855-65. ©2016 AACR.

Interactions of microorganisms with polymer nanocomposite surfaces containing oxidized carbon nanotubes.

In many environmental scenarios, the fate and impact of polymer nanocomposites (PNCs) that contain carbon nanotubes (CNT/PNCs) will be influenced by their interactions with microorganisms, with implications for antimicrobial properties and the long-term persistence of PNCs. Using oxidized single-wall (O-SWCNTs) and multi-wall CNTs (O-MWCNTs), we explored the influence that CNT loading (mass fraction≤0.1%-10%) and type have on the initial interactions of Pseudomonas aeruginosa with O-CNT/poly(vinyl alcohol) (PVOH) nanocomposites containing well-dispersed O-CNTs. LIVE/DEAD staining revealed that, despite oxidation, the inclusion of O-SWCNTs or O-MWCNTs caused PNC surfaces to exhibit antimicrobial properties. The fraction of living cells deposited on both O-SWCNT and O-MWCNT/PNC surfaces decreased exponentially with increasing CNT loading, with O-SWCNTs being approximately three times more cytotoxic on a % w/w basis. Although not every contact event between attached microorganisms and CNTs led to cell death, the cytotoxicity of the CNT/PNC surfaces scaled with the total contact area that existed between the microorganisms and CNTs. However, because the antimicrobial properties of CNT/PNC surfaces require direct CNT-microbe contact, dead cells were able to shield living cells from the cytotoxic effects of CNTs, allowing biofilm formation to occur on CNT/PNCs exposed to Pseudomonas aeruginosa for longer time periods.

Corticosteroids provoke acute endothelial injury -- an ideal ground for thrombosis in multiple sclerosis.

Despite the effect corticosteroids exert on blood clotting and the irrefutable impact of intracranial sure decreasing shortly after lumbar puncture, a certain number of intracranial thromboses remain unexplained. Corticosteroids are useful in reducing the severity and duration of relapses of multiple sclerosis. Several questions emerge concerning the reasons behind thrombosis occurring so sporadically, not pertaining to any rule, the most important of which regard the location and timing. We developed this hypothesis as an obverse to chronic endothelial injury theory which, only partially explains atherosclerosis development. We followed Virchows classical triad of conditions which are believed to be connected to the development of thrombosis. Although corticosteroids affect more than vessel wall injury, component of Virchows triad that has been our narrowest interest is exactly vessel wall injury.

Percepción de las actitudes éticas de la enfermería de cuidados intensivos ante la limitación del tratamiento / Perception of ethical attitudes of intensive care nurses on treatment limitation

Objetivo Analizar la percepción de la enfermería de cuidados intensivos acerca de la limitación del esfuerzo terapéutico (LET). Método Estudio transversal, descriptivo durante 2 meses, llevado a cabo entre el personal de enfermería de cuidados intensivos de nuestro Hospital. Se utilizó una encuesta anónima, para valorar las actitudes de la enfermería de cuidados intensivos acerca de la LET. Resultados Cincuenta y dos enfermeros/as (86,6%), 57,7% mujeres, con un tiempo trabajado de 8,8±4,8 años y el 17,7% poseía alguna formación suplementaria en ética. La decisión de no ingresar a un paciente con una calidad de vida muy mala a corto plazo cambia cuando se tiene en cuenta la opinión del paciente (36,5% vs 61,5%; p=0,008), diferencia que la marcan los varones sin formación previa en ética. El 23,1% desconoce que existen en el servicio unas guías consensuadas sobre LET. Un 17,3% piensa que limitar un tratamiento, bien no suministrándoselo o retirándolo, es una forma de eutanasia pasiva, que sería una práctica aceptable a diferencia de la eutanasia. 84,6% piensa que no es lo mismo administrar un tratamiento que retirarlo. El 36,5% opina que la enfermería no debería participar en la decisión de limitar un tratamiento, así como tampoco los pacientes (34,6%) ni los familiares (23,1%).Conclusiones La enfermería no es consciente de la importancia que puede tener, junto a familiares y pacientes, en la toma de decisiones en relación a la limitación del tratamiento del paciente crítico, aportando su visión humanizadora y ética de los cuidados (AU)

Objective Analyze the perception of intensive care nurses regarding the limitation of therapeutic efforts (LET).Method A 2-month cross-sectional, descriptive study carried out among Intensive Care nursing staff of our Hospital. An anonymous survey was used to assess the attitudes of intensive care nurses on LET.Results Fifty-two nurses (86.6%), 57.7% women, with a working experience of 8.8±4.8 years and 17.7%, had some additional training in ethics. The decision not to hospitalize a patient whose short term quality of life is very poor changes when the patient's opinion is considered (36.5% vs 61.5%, p=0.008), a difference that is greater in male nurses without prior training in ethics. A total of 23.1% were not aware of the existence of agreed on guidelines on LET in the Service. A total of 17.3% consider that limiting treatment, either by not providing it or by withdrawing it, is a form of passive euthanasia, which would be an acceptable practice as opposed to euthanasia and 84.6% consider that administering a treatment is not the same as withdrawing it. Of those surveyed, 36.5% felt that the neither the nursing staff should not participate in the decision to limit treatment nor the patients (34.6%) nor family (23.1%).ConclusionsNursing is not aware of the importance it can have, along with the family and patient, in decision making in relationship to the limitation of the treatment of the critical patient, providing a humanizing and ethical view of the care (AU)

[Perception of ethical attitudes of intensive care nurses on treatment limitation]. / Percepción de las actitudes éticas de la enfermería de cuidados intensivos ante la limitación del tratamiento.

OBJECTIVE: Analyze the perception of intensive care nurses regarding the limitation of therapeutic efforts (LET). METHOD: A 2-month cross-sectional, descriptive study carried out among Intensive Care nursing staff of our Hospital. An anonymous survey was used to assess the attitudes of intensive care nurses on LET. RESULTS: Fifty-two nurses (86.6%), 57.7% women, with a working experience of 8.8±4.8 years and 17.7%, had some additional training in ethics. The decision not to hospitalize a patient whose short term quality of life is very poor changes when the patient's opinion is considered (36.5% vs 61.5%, p=0.008), a difference that is greater in male nurses without prior training in ethics. A total of 23.1% were not aware of the existence of agreed on guidelines on LET in the Service. A total of 17.3% consider that limiting treatment, either by not providing it or by withdrawing it, is a form of passive euthanasia, which would be an acceptable practice as opposed to euthanasia and 84.6% consider that administering a treatment is not the same as withdrawing it. Of those surveyed, 36.5% felt that the neither the nursing staff should not participate in the decision to limit treatment nor the patients (34.6%) nor family (23.1%). CONCLUSIONS: Nursing is not aware of the importance it can have, along with the family and patient, in decision making in relationship to the limitation of the treatment of the critical patient, providing a humanizing and ethical view of the care.

Elimination of a pressure ulcer with electrical stimulation--a case study

Pressure ulcers, also called decubitus ulcers, are a common challenge of humanity and are exceptionally difficult to heal. They are wounds that are initiated by relatively short periods of pressure on the skin that blocks blood circulation causing the skin and underlying tissues to die, leading to an open wound. Pressure release can prevent further tissue degeneration, and some ulcers heal and disappear by themselves. However, many pressure ulcers never heal and continue to grow in diameter and depth. By one year, such unhealing ulcers are referred to as chronic ulcers. Chronic ulcers frequently jeopardize the life of the patient due to infections that become increasingly deep until they invade bones and the circulatory system. We report on a patient with a chronic pressure ulcer at his coccyx prominence. Fourteen months after the ulcer had appeared, a surface pulse electromagnetic force (PEMF) stimulator was applied over T7-T8, 45 cm cephalic to the ulcer, as part of a nerve stimulation study. Although the ulcer had continued to grow both in diameter and depth for 14 months and showed no signs of healing, within 6 days of applying the PEMF stimulator, the ulcer began to heal and was fully eliminated after 3 months. We concluded that the electrical stimulation induced the healing of the pressure ulcer. The ulcer elimination is quite surprising due to the exceptionally low electric field-force being generated by the stimulator at a distance of 45 cm.

A novel technique leading to complete sensory and motor recovery across a long peripheral nerve gap

Sensory nerve grafts are the [quot ]gold standard[quot ] for inducing neurological recovery in peripheral nerves with a gap. However, the effectiveness of sensory nerve grafts is variable, generally not leading to complete sensory and motor recovery, with good recovery limited to gaps shorter than 2 cm, and the extent of recovery decreasing with increasing graft length. An alternative technique using a conduit filled with pure fibrin to bridge a nerve gap leads to only limited neurological recovery. We tested the effectiveness of a novel nerve repair technique in which a 5-cm long radial nerve gap was repaired using two sural nerve graft surrounded by a collage tube filled with pure fibrin. By 1 1/2 years post surgery, the patient recovered complete sensory and motor function. In conclusion, this study suggests that the combination of pure fibrin surrounding sural nerve grafts is responsible for inducing the extensive neurological recovery induced by either pure fibrin or sural grafts alone. This technique is presently being tested in a clinical trial.

Morphological characterization of six subpopulations of adult human DRG neurons at the light microscopic level

Dorsal root ganglion (DRG) neurons are composed of physiologically distinct subpopulations, each responding to a different sensory stimulus. One can morphologically discriminate between two broad populations of adult rat and frog DRG neurons by their appearance under the light microscope. These groups are called large clear and small dark. However, additional subpopulations have not been identified by visual observation. Such identification requires application of immunochemistry or biophysical techniques. Although these are useful techniques, they do not allow the rapid discrimination of different neuron subpopulations, which would be useful for pharmacological studies on unique neuron subpopulations. Such experiments would be greatly facilitated if viable DRG neuron subpopulations could be identified based on their morphology at the light microscopic level. Just as for adult frog and rat DRG neurons, when adult human DRG neurons are observed under phase optics, two subpopulations can be seen, small dark and large light. However, under bright-field illumination, six distinct subpopulations can be distinguished based solely on morphological features. Five subpopulations contain rusty-colored cytoplasmic inclusions with different sized granules and differences in the size and density of the granule clusters, while one is granule-free. Analysis of the soma diameter distribution shows each of the six granule-containing and the non-granule-containing (clear) neuron subpopulations has a statistically significant difference in size distribution. We propose that neurons with different morphologies correspond to unique physiological subpopulations of DRG neurons. Experiments are underway using immunochemical techniques to determine whether neurons with the unique morphologies correspond with unique physiological functions.

Neuroprotection of adult human neurons against ischemia by hypothermia and alkalinization

Ischemia of intact dorsal root ganglia (DRG) in situ leads to massive neuron death due to ischemia-triggered secondary events, such as massive release of excitatory amino acids from the neurons, their excessive accumulation and activation of neuron NMDA and other receptors, acidification, and loss of calcium homeostasis. The present experiments tested whether hypothermia and alkalinization, separately or combined, provide neuroprotection against 1-4 hours of ischemia to the neurons within intact DRG acutely removed from organ donors. DRG under hypothermic (20-15 degrees C) or alkaline (pH 8.0-9.3) conditions yielded more viable neurons than DRG maintained under physiological conditions (37 degrees C/pH 7.4), 4.1-fold vs. 7.8-fold respectively, but, hypothermia and alkalinization combined (20 degrees C/pH 9.3) increased the yield of viable neurons 26-fold compared to DRG maintained under physiological conditions. These results show that combined hypothermia and alkalinization provide adult human DRG neurons significant neuroprotection against ischemia, and ischemia-induced causes of neuron death.

Hepatitis B immune status of non-injecting drugusers 18- to 25-years-old in Puerto Rico.

INTRODUCTION: Ilicit drug users are the population group at highest risk of HBV infection in most Western countries. In this study we assessed hepatitis B virus (HBV) immune status in a cohort of young non-injecting drug users in Puerto Rico. METHODS: Subjects were eligible if they were 18- to 25-years-old, had never injected any drugs, and had recently used heroin or cocaine. A total of 541 subjects were recruited from community settings during 2004 and 2005. Subjects were interviewed and tested for HBV immune status and infection. RESULTS: Overall, 36.6% showed evidence of HBV immunity. Among subjects not HBV immune, 63.0% reported being vaccinated against HBV. Rates of HBV immunity were 47.6% among subjects who were 12-years-old or less in 1995 when mandatory school verification of HBV vaccination was established and 23.0% among those who were older than 12 in 1995 (p<.001). HBV immunity was 52.5% among non intravenous drug user who were 12-years-old or less in 1995 if they had not dropped out of school before the 8th grade compared to 23.9% (p<.001) among those who did drop out before the 8th grade. CONCLUSIONS: Mandatory school verification of HBV vaccination seems to have had a substantial effect in increasing coverage among young illicit drug users. However, the impact of mandatory school verification appears to be limited by the fact that many illicit drug users drop out of school early after completing the primary level.

Advances in spinal cord repair techniques

Daily US accidents result annually in over 20,000 cases of traumatic spinal cord injury associated with complete and permanent paraplegias and quadriplegias frequently associated chronic pain. This amounts to new annual health care a costs of dollar 3.2 billion, and a total annual cost for all such individuals in the US of dollar 96 billion. Tens of thousands of additional people suffer lesser degrees of permanent debilitating lost spinal cord function. To help these people recover neurological functions, and simultaneously reduce the enormous suffering, and the associated medical expenses, requires developing techniques that induce the regeneration of lesioned adult human spinal cord axons. A number of techniques lead to varying degrees of axon regeneration and neurological recovery in the rat, but the recovery is invariably limited. While other approaches show potential, they have not led reliable neurological recovery. Most spinal cord repair techniques cannot be applied clinically because they require materials that are not FDA-approved. However, several FDA-approved materials are available that hold great promise for inducing axon regeneration, especially when used simultaneously. Here we review efforts to induce the regeneration of spinal cord axons, how what is known about promoting regeneration of axons across peripheral nerve gaps may be applied to repairing spinal cord lesions, and finally, how several readily available materials may induce axons to regenerate in the spinal cord and restore neurological function.