SAFETY AND EFFICACY OF THYMIC PEPTIDES IN THE TREATMENT OF HOSPITALIZED COVID-19 PATIENTS IN HONDURAS.

Coronavirus disease 2019 (Covid-19) active cases continue to demand the development of safe and effective treatments. This is the first clinical trial to evaluate the safety and efficacy of oral thymic peptides. ; We conducted a nonrandomized phase 2 trial with a historic control group to evaluate the safety and efficacy of a daily 250-mg oral dose of thymic peptides in the treatment of hospitalized Covid-19 patients. Comparisons based on standard care from registry data were performed after propensity score matching. The primary outcomes were survival, time to recovery, and number of participants with treatment-related adverse events or side effects by day 20. ; A total of 44 patients were analyzed in this study: 22 in the thymic peptide group and 22 in the standard care group. There were no deaths in the intervention group compared to 24% mortality in standard care by day 20 (log-rank P=0.02). Kaplan-Meier analysis showed a significantly shorter time to recovery by day 20 in the thymic peptide group than in the standard care group (median, 6 days vs. 12 days; hazard ratio for recovery, 2.75 [95% confidence interval, 1.34 to 5.62]; log-rank P=0.002). No side effects or adverse events were reported. ; In patients hospitalized with Covid-19, the use of thymic peptides resulted in no side effects, adverse events, or deaths by day 20. Compared with the registry data, a significantly shorter time to recovery and mortality reduction were measured.

Medical education from the point of view of medical students: Results from four participatory Delphi panels in Quito, Ecuador.

BACKGROUND: Medical curricula have historically been designed in a top-down approach, usually excluding students. While Delphi panels have been used as a tool for medical education curricula design, none have been conducted in Ecuador. In addition, no such approach has ever included students both as panelists and researchers. MATERIAL AND METHODS: Four Delphi panels were developed and conducted using a participatory approach that allowed medical students to take part both as expert panelists and researchers: specifically, students developed the questionnaire and conducted a qualitative synthesis. Questionnaire responses were anonymized and dispatched online to panelists. The information was organized and collected to develop the qualitative syntheses and prepare the final statements. RESULTS: Thirty-two medical students participated between February and May 2018. A total of 32 questions were developed, corresponding to five different categories. For some questions, consensus was reached; for other questions, general statements were obtained.Discussion and conclusion: Developing the questionnaire, responding to it and analyzing the answers allowed students to raise significant concerns regarding medical education topics proposing relevant policy and curricula change. Participatory Delphi panels can be an efficient tool to obtain organized feedback, improve student class involvement, and promote research skills.

In vitro antimicrobial activity against equine Lawsonia intracellularis strains.

BACKGROUND: Lawsonia intracellularis is the aetiologic agent of equine proliferative enteropathy (EPE). This emerging equine disease leads to diarrhoea, severe protein loss and can result in death if left untreated. Timely treatment of EPE is critical for recovery from the disease, and hence, information about antimicrobial susceptibilities of equine L. intracellularis strains to antimicrobials used in horses is needed. However, L. intracellularis is an obligate intracellular bacterium and so must be isolated and maintained in cell cultures. OBJECTIVES: To determine the in vitro antimicrobial activity of 14 antimicrobials against two equine L. intracellularis strains. STUDY DESIGN: In vitro experiments. METHODS: This study was designed to compare the relative in vitro susceptibility of each strain of L. intracellularis to different antimicrobials which included metronidazole, minocycline hydrochloride, erythromycin, cephalothin sodium salt, combination (4:1) of sulfamethazine and trimethoprim, chloramphenicol, rifampicin, penicillin, ampicillin, doxycycline hydrochloride, cefazolin sodium salt, clarithromycin, ceftiofur hydrochloride and enrofloxacin. The minimum inhibitory concentration (MIC) was based on intracellular and extracellular activity that inhibited 99% of L. intracellularis growth in cell culture as compared to the antimicrobial-free control. RESULTS: Rifampicin and clarithromycin were the most active antimicrobials against the two L. intracellularis strains tested, with MICs of ≤0.125 when tested both intracellularly and extracellularly. Doxycycline, minocycline, erythromycin, chloramphenicol and enrofloxacin showed intermediate to high activity, and activity was generally higher when evaluating intracellular activity. Sulfamethazine/trimethoprim showed variable results. Ampicillin, penicillin and metronidazole had low to moderate activity. L. intracellularis was resistant to cefazolin, cephalothin and ceftiofur in in vitro conditions. MAIN LIMITATIONS: Only two equine isolates of L. intracellularis were available for this study due to the difficulty in isolating this obligate intracellular species from intestinal samples. CONCLUSIONS: This is the first report of antimicrobial susceptibility patterns for equine L. intracellularis strains.

Growth performance, carcass traits and breast meat fatty acids profile of helmeted guinea fowls (Numida meleagris) fed increasing level of linseed (Linum usitatissimum) and pumpkin seed (Cucurbita moschata) meals

This study was conducted to determine the effects of dietary inclusion with linseed and pumpkin seed meals on growth performance, carcass traits and breast meat fatty acids profile of helmeted guinea fowls. A total of 120 meat-type helmeted guinea fowl females of 12 weeks of age were fed with 0 (T0), 100 (T1) and 200 (T2) g/kg of linseed (LM) and pumpkin seed meals (PSM) for 56 days, in a completely randomized design with 10 replicates per treatment and four birds per replicate. The inclusion up to 200 g/kg of LM and PSM did not affect the livability, initial live weight and feed intake (p>0.05). However, final live weight and feed:gain ratio improved significantly (p0.05). The oleaginous seeds (LM and PSM) decreased (p0.05) and the eicosatrienoic and arachidonic acids in breast meat (p<0.05). It is recommended the inclusion of 100 g/kg of LM and PSM to improve the live weight, weight and yield of the edible portions and the essential fatty acids in breast meat of guinea fowl, without affecting the sensory quality of the meat.

Growth performance, carcass traits and breast meat fatty acids profile of helmeted guinea fowls (Numida meleagris) fed increasing level of linseed (Linum usitatissimum) and pumpkin seed (Cucurbita moschata) meals

This study was conducted to determine the effects of dietary inclusion with linseed and pumpkin seed meals on growth performance, carcass traits and breast meat fatty acids profile of helmeted guinea fowls. A total of 120 meat-type helmeted guinea fowl females of 12 weeks of age were fed with 0 (T0), 100 (T1) and 200 (T2) g/kg of linseed (LM) and pumpkin seed meals (PSM) for 56 days, in a completely randomized design with 10 replicates per treatment and four birds per replicate. The inclusion up to 200 g/kg of LM and PSM did not affect the livability, initial live weight and feed intake (p>0.05). However, final live weight and feed:gain ratio improved significantly (p<0.05). The T1 increased (p<0.05) the carcass yield and the T2 improved the breast weight and weight and yield of leg. Also, these experimental diets did not affect the carcass weight, breast yield and sensory quality of meat (p>0.05). The oleaginous seeds (LM and PSM) decreased (p<0.05) the mystic, palmitic and octadecanoic acids and the w-6/w-3 ratio, as well as increased the linoleic, a-linolenic, eicosapentanoic and docosahexanoic acids (p<0.05), but did not modify the concentration of monounsaturated fatty acids (p>0.05) and the eicosatrienoic and arachidonic acids in breast meat (p<0.05). It is recommended the inclusion of 100 g/kg of LM and PSM to improve the live weight, weight and yield of the edible portions and the essential fatty acids in breast meat of guinea fowl, without affecting the sensory quality of the meat.(AU)

Pleuropulmonary involvement in patients with systemic lupus erythematosus from a Latin American inception cohort (GLADEL).

Objectives The objectives of this study were to examine the demographic and clinical features associated with the occurrence of pleuropulmonary manifestations, the predictive factors of their occurrence and their impact on mortality in systemic lupus erythematosus (SLE) patients. Materials and methods The association of pleuropulmonary manifestations with demographic and clinical features, the predictive factors of their occurrence and their impact on mortality were examined in GLADEL patients by appropriate univariable and multivariable analyses. Results At least one pleuropulmonary manifestation occurred in 421 of the 1480 SLE patients (28.4%), pleurisy being the most frequent (24.0%). Age at SLE onset ≥30 years (OR 1.42; 95% CI 1.10-1.83), the presence of lower respiratory tract infection (OR 3.19; 95% CI 2.05-4.96), non-ischemic heart disease (OR 3.17; 95% CI 2.41-4.18), ischemic heart disease (OR 3.39; 95% CI 2.08-5.54), systemic (OR 2.00; 95% CI 1.37-2.91), ocular (OR 1.58; 95% CI 1.16-2.14) and renal manifestations (OR 1.44; 95% CI 1.09-1.83) were associated with pleuropulmonary manifestations, whereas cutaneous manifestations were negatively associated (OR 0.47; 95% CI 0.29-0.76). Non-ischemic heart disease (HR 2.24; 95% CI 1.63-3.09), SDI scores ≥1 (OR 1.54; 95% CI 1.10-2.17) and anti-La antibody positivity (OR 2.51; 95% CI 1.39-4.57) independently predicted their subsequent occurrence. Cutaneous manifestations were protective of the subsequent occurrence of pleuropulmonary manifestations (HR 0.62; 95% CI 0.43-0.90). Pleuropulmonary manifestations independently contributed a decreased survival (HR: 2.79 95% CI 1.80-4.31). Conclusion Pleuropulmonary manifestations are frequent in SLE, particularly pleuritis. Older age, respiratory tract infection, cardiac, systemic and renal involvement were associated with them, whereas cutaneous manifestations were negatively associated. Cardiac compromise, SDI scores ≥1 and anti-La positivity at disease onset were predictive of their subsequent occurrence, whereas cutaneous manifestations were protective. They independently contributed to a decreased survival in these patients.

Incontinencia Pigmenti: rara genodermatosis ligada con el cromosoma X. Reporte de un caso clínico / Incontinentia pigmenti: a rare X-linked genodermatosis. A case report / Incontinência pigmenti: rara genodermatose ligada com o cromossoma x. Reporte de um caso clínico

La incontinencia pigmenti (síndrome de Bloch-Sulzberger) es una genodermatosis rara causada por una mutación en el gen NEMO localizado en el cromosoma X. Las manifestaciones cutáneas son marcadoras de esta entidad y se dan de forma temprana y cronológica. El compromiso extra cutáneo se da hasta en el 80% de los casos y las alteraciones neurológicas y oftalmológicas son marcadores del pronóstico porque tienen el potencial de producir secuelas irreversibles. Se presenta el caso de una paciente que desde el primer día de vida inició con lesiones cutáneas que, con la evolución, desarrollaron características clásicas de una incontinencia pigmenti. Se resalta el antecedente familiar asociado, el compromiso neurológico extenso y la importancia de un manejo multidisciplinario.

Incontinentia pigmenti (Bloch-Sulzberger Syndrome) is a rare genodermatosis. The disease is X-linked and the most common molecular defect includes mutations in the NEMO gene on chromosome Xq28 in approximately 70% of patients. It is characterized by a multisystem compromise in which the skin manifestations occur in all patients. Also, the dermatological findings occur early and in chronological order. The prevalence of extra skin compromise is approximately 80% of patients. The ophthalmological and neurological manifestations are the major cause of disability in patients and may have a great impact on the quality of life. Some of damages are irreversible. We present the clinical case of a child on her first day of life. It began with skin manifestations typical of incontinentia pigmenti and extensive neurological involvement. In addition, the family history includes a sister with the disease. A multidisciplinary approach is necessary to care for patients and to detect and prevent long-term complications.

A incontinência pigmenti (síndrome de Bloch-Sulzberger) é uma genodermatose rara causada por uma mutação no gene NEMO localizado no cromossoma X. As manifestações cutâneas são marcadoras desta entidade E se dá de forma precoce e cronológica. O compromisso extra cutâneo se dá até em 80% dos casos e as alterações neurológicas e oftalmológicas são marcadores do prognóstico porque tem o potencial de produzir sequelas irreversíveis. Se apresenta o caso de uma paciente que desde o primeiro dia de vida iniciou com lesões cutâneas que, com a evolução, desenvolveram características clássicas de uma incontinência pigmenti. Se ressalta o antecedente familiar associado, o compromisso neurológico extenso e a importância de um manejo multidisciplinar.

Role of pulmonary stretch receptors and sympathetic system in the inhibition of reflex bradycardia produced by chemical stimulation of the periaqueductal gray matter of the rat.

The present study examined the role of the sympathetic system and pulmonary afferent feedback in the baroreflex inhibition by chemical stimulation of the dorsal periaqueductal gray matter (DPAG) of the anesthetized rat. The baroreflex bradycardia was induced by phenylephrine infusions (PHE, 50 µg/ml/min, i.v.) given either alone or combined with glutamate microinjections (GLU, 10 nmol/100 nl) into the DPAG. GLU microinjections alone produced marked increases in respiratory amplitude (67±19%), but barely changed the respiratory frequency (15±3 cpm) and blood pressure (14±2 mm Hg), and did not affect the heart rate. In contrast, the same injections produced a 92% inhibition of PHE-induced bradycardia (from -62 to -5 bpm). Because GLU microinjections per se had little effects on blood pressure, the baroreflex inhibition should be credited to the deactivation of both the vagal and sympathetic reflex pathways at the medulla. Indeed, the baroreflex was inhibited in only 47% following the DPAG stimulation of atenolol-treated rats. The GLU-evoked inhibition of baroreflex was also correlated with concomitant increases in respiratory amplitude. The role of pulmonary feedback in baroreflex inhibition was thus examined before and after the neuromuscular blockade of atenolol-treated rats. In spontaneously breathing rats, GLU microinjections reversed PHE-induced bradycardia to tachycardia, thereby producing a 153% inhibition of reflex bradycardia (from -38 bpm to +20 bpm). In contrast, the baroreflex inhibition was attenuated in only 53% after neuromuscular blockade (from -34 to -16 bpm). Data are the first evidence of the contribution of pulmonary stretch receptor feedback in DPAG-evoked inhibition of reflex bradycardia.

Oral rapamycin attenuates atherosclerosis without affecting the arterial responsiveness of resistance vessels in apolipoprotein E-deficient mice

The objective of the present study was to assess the effects of the immunosuppressant rapamycin (Rapamune®, Sirolimus) on both resistance vessel responsiveness and atherosclerosis in apolipoprotein E-deficient 8-week-old male mice fed a normal rodent diet. Norepinephrine (NE)-induced vasoconstriction, acetylcholine (ACh)- and sodium nitroprusside (SNP)-induced vasorelaxation of isolated mesenteric bed, and atherosclerotic lesions were evaluated. After 12 weeks of orally administered rapamycin (5 mg·kg-1·day-1, N = 9) and compared with untreated (control, N = 9) animals, rapamycin treatment did not modify either NE-induced vasoconstriction (maximal response: 114 ± 4 vs 124 ± 10 mmHg, respectively) or ACh- (maximal response: 51 ± 8 vs 53 ± 5 percent, respectively) and SNP-induced vasorelaxation (maximal response: 73 ± 6 vs 74 ± 6 percent, respectively) of the isolated vascular mesenteric bed. Despite increased total cholesterol in treated mice (982 ± 59 vs 722 ± 49 mg/dL, P < 0.01), lipid deposition on the aorta wall vessel was significantly less in rapamycin-treated animals (37 ± 12 vs 68 ± 8 µm² x 10³). These results indicate that orally administered rapamycin is effective in attenuating the progression of atherosclerotic plaque without affecting the responsiveness of resistance vessels, supporting the idea that this immunosuppressant agent might be of potential benefit against atherosclerosis in patients undergoing therapy.

Varicocele testicular en adolescentes / Testicular varicocele in adolescent

El varicocele testicular es una patología asociada a la infertilidad del varón. Su mayor prevalencia se presenta en la adolescencia y existen reportes que sugieren que desde esta edad el desarrollo de la espermatogénesis de los adolescentes con varicocele se encuentra comprometido en comparación con los que no lo tienen. Hay que tener presente dos situaciones: una relacionada con las causas por las cuales se presentan las varices y el reflujo venoso en las venas testiculares y su tratamiento, y otra, el daño que ocasionan las varices en la espermatogénesis. Este artículo presenta una revisión de los hallazgos más importantes que explican los mecanismos de la alteración de la fertilidad del varón adolescente que presenta varicocele, por lo que se hace necesario realizar otros estudios que complementen estos hallazgos...

The testicular varicocele is a pathology associated with male infertility. Its highest prevalence occurs in adolescence and there are reports that suggest that from this age the development of spermatogenesis in adolescents with varicocele is compromised compared with those without. It is necessary to have present two situations: one related to the causes which have varicose veins and venous reflux in the testicular veins and their treatment and other damage caused varicose veins in spermatogenesis. This article presents a review of the most important findings that explain the mechanisms of the impaired fertility of male adolescents with varicocele...

Oral rapamycin attenuates atherosclerosis without affecting the arterial responsiveness of resistance vessels in apolipoprotein E-deficient mice.

The objective of the present study was to assess the effects of the immunosuppressant rapamycin (Rapamune, Sirolimus) on both resistance vessel responsiveness and atherosclerosis in apolipoprotein E-deficient 8-week-old male mice fed a normal rodent diet. Norepinephrine (NE)-induced vasoconstriction, acetylcholine (ACh)- and sodium nitroprusside (SNP)-induced vasorelaxation of isolated mesenteric bed, and atherosclerotic lesions were evaluated. After 12 weeks of orally administered rapamycin (5 mg.kg-1.day-1, N = 9) and compared with untreated (control, N = 9) animals, rapamycin treatment did not modify either NE-induced vasoconstriction (maximal response: 114 +/- 4 vs 124 +/- 10 mmHg, respectively) or ACh- (maximal response: 51 +/- 8 vs 53 +/- 5%, respectively) and SNP-induced vasorelaxation (maximal response: 73 +/- 6 vs 74 +/- 6%, respectively) of the isolated vascular mesenteric bed. Despite increased total cholesterol in treated mice (982 +/- 59 vs 722 +/- 49 mg/dL, P < 0.01), lipid deposition on the aorta wall vessel was significantly less in rapamycin-treated animals (37 +/- 12 vs 68 +/- 8 microm(2) x 10(3)). These results indicate that orally administered rapamycin is effective in attenuating the progression of atherosclerotic plaque without affecting the responsiveness of resistance vessels, supporting the idea that this immunosuppressant agent might be of potential benefit against atherosclerosis in patients undergoing therapy.

Endogenous angiotensin II modulates nNOS expression in renovascular hypertension.

Nitric oxide (NO) influences renal blood flow mainly as a result of neuronal nitric oxide synthase (nNOS). Nevertheless, it is unclear how nNOS expression is modulated by endogenous angiotensin II, an inhibitor of NO function. We tested the hypothesis that the angiotensin II AT1 receptor and oxidative stress mediated by NADPH oxidase contribute to the modulation of renal nNOS expression in two-kidney, one-clip (2K1C) hypertensive rats. Experiments were performed on male Wistar rats (150 to 170 g body weight) divided into 2K1C (N = 19) and sham-operated (N = 19) groups. nNOS expression in kidneys of 2K1C hypertensive rats (N = 9) was compared by Western blotting to that of 2K1C rats treated with low doses of the AT1 antagonist losartan [10 mg x kg(-1) x day(-1); N = 5] or the superoxide scavenger tempol [0.2 mmol x kg(-1) x day(-1); N = 5], which still remain hypertensive. After 28 days, nNOS expression was significantly increased by 1.7-fold in the clipped kidneys of 2K1C rats and by 3-fold in the non-clipped kidneys of 2K1C rats compared with sham rats, but was normalized by losartan. With tempol treatment, nNOS expression increased 2-fold in the clipped kidneys and 1.4-fold in the non-clipped kidneys compared with sham rats. The changes in nNOS expression were not followed by changes in the enzyme activity, as measured indirectly by the cGMP method. In conclusion, AT1 receptors and oxidative stress seem to be primary stimuli for increased nNOS expression, but this up-regulation does not result in higher enzyme activity.

Endogenous angiotensin II modulates nNOS expression in renovascular hypertension

Nitric oxide (NO) influences renal blood flow mainly as a result of neuronal nitric oxide synthase (nNOS). Nevertheless, it is unclear how nNOS expression is modulated by endogenous angiotensin II, an inhibitor of NO function. We tested the hypothesis that the angiotensin II AT1 receptor and oxidative stress mediated by NADPH oxidase contribute to the modulation of renal nNOS expression in two-kidney, one-clip (2K1C) hypertensive rats. Experiments were performed on male Wistar rats (150 to 170 g body weight) divided into 2K1C (N = 19) and sham-operated (N = 19) groups. nNOS expression in kidneys of 2K1C hypertensive rats (N = 9) was compared by Western blotting to that of 2K1C rats treated with low doses of the AT1 antagonist losartan (10 mg·kg-1·day-1; N = 5) or the superoxide scavenger tempol (0.2 mmol·kg-1·day-1; N = 5), which still remain hypertensive. After 28 days, nNOS expression was significantly increased by 1.7-fold in the clipped kidneys of 2K1C rats and by 3-fold in the non-clipped kidneys of 2K1C rats compared with sham rats, but was normalized by losartan. With tempol treatment, nNOS expression increased 2-fold in the clipped kidneys and 1.4-fold in the non-clipped kidneys compared with sham rats. The changes in nNOS expression were not followed by changes in the enzyme activity, as measured indirectly by the cGMP method. In conclusion, AT1 receptors and oxidative stress seem to be primary stimuli for increased nNOS expression, but this up-regulation does not result in higher enzyme activity.

Influence of renal denervation on blood pressure, sodium and water excretion in acute total obstructive apnea in rats.

Obstructive apnea (OA) can exert significant effects on renal sympathetic nerve activity (RSNA) and hemodynamic parameters. The present study focuses on the modulatory actions of RSNA on OA-induced sodium and water retention. The experiments were performed in renal-denervated rats (D; N = 9), which were compared to sham (S; N = 9) rats. Mean arterial pressure (MAP) and heart rate (HR) were assessed via an intrafemoral catheter. A catheter was inserted into the bladder for urinary measurements. OA episodes were induced via occlusion of the catheter inserted into the trachea. After an equilibration period, OA was induced for 20 s every 2 min and the changes in urine, MAP, HR and RSNA were recorded. Renal denervation did not alter resting MAP (S: 113 +/- 4 vs D: 115 +/- 4 mmHg) or HR (S: 340 +/- 12 vs D: 368 +/- 11 bpm). An OA episode resulted in decreased HR and MAP in both groups, but D rats showed exacerbated hypotension and attenuated bradycardia (S: -12 +/- 1 mmHg and -16 +/- 2 bpm vs D: -16 +/- 1 mmHg and 9 +/- 2 bpm; P < 0.01). The basal urinary parameters did not change during or after OA in S rats. However, D rats showed significant increases both during and after OA. Renal sympathetic nerve activity in S rats increased (34 +/- 9%) during apnea episodes. These results indicate that renal denervation induces elevations of sodium content and urine volume and alters bradycardia and hypotension patterns during total OA in unconscious rats.

Influence of renal denervation on blood pressure, sodium and water excretion in acute total obstructive apnea in rats

Obstructive apnea (OA) can exert significant effects on renal sympathetic nerve activity (RSNA) and hemodynamic parameters. The present study focuses on the modulatory actions of RSNA on OA-induced sodium and water retention. The experiments were performed in renal-denervated rats (D; N = 9), which were compared to sham (S; N = 9) rats. Mean arterial pressure (MAP) and heart rate (HR) were assessed via an intrafemoral catheter. A catheter was inserted into the bladder for urinary measurements. OA episodes were induced via occlusion of the catheter inserted into the trachea. After an equilibration period, OA was induced for 20 s every 2 min and the changes in urine, MAP, HR and RSNA were recorded. Renal denervation did not alter resting MAP (S: 113 ± 4 vs D: 115 ± 4 mmHg) or HR (S: 340 ± 12 vs D: 368 ± 11 bpm). An OA episode resulted in decreased HR and MAP in both groups, but D rats showed exacerbated hypotension and attenuated bradycardia (S: -12 ± 1 mmHg and -16 ± 2 bpm vs D: -16 ± 1 mmHg and 9 ± 2 bpm; P < 0.01). The basal urinary parameters did not change during or after OA in S rats. However, D rats showed significant increases both during and after OA. Renal sympathetic nerve activity in S rats increased (34 ± 9 percent) during apnea episodes. These results indicate that renal denervation induces elevations of sodium content and urine volume and alters bradycardia and hypotension patterns during total OA in unconscious rats.

Phantom reflexes: muscle contractions at a frequency not physically present in the input stimuli.

In the motor system, the periodic stimulation of one Ia-afferent input produces reflex muscle contractions at the input frequency. However, we observed that when two Ia monosynaptic reflex-afferent inputs are involved the periodic muscle contractions may occur at a frequency physically not present in the afferent inputs even when these inputs are sub-threshold. How can the muscles respond with such phantom reflex contractions at a frequency physically absent in the sub-threshold Ia-afferent input stimuli? Here we provide an explanation for this phenomenon in the cat spinal cord, that we termed "ghost motor response". We recorded monosynaptic reflexes in the L7 ventral root, intracellular potentials in the motoneurons, and the associated muscular contractions elicited by stimulation of the lateral and medial gastrocnemius nerves. By stimulating with periodic pulses of sub-threshold intensities and distinct frequencies of 2 and 3 Hz the lateral and medial gastrocnemius nerves, respectively, we observed monosynaptic responses and phantom reflex muscle contractions occurring at the fundamental frequency (1 Hz), which was absent in the input stimuli. Thus we observed a reflex ghost motor response at a frequency not physically present in the inputs. We additionally studied the inharmonic case for sub-threshold stimuli and observed muscular contractions occurring at much lower frequencies, which were also conspicuously absent in the inputs. This is the first experimental evidence of a phantom reflex response in the nervous system. The observed behavior was modeled by numerical simulations of a pool of neurons subjected to two different input pulses.

Incidencia de úlceras por presión en población hospitalizada con factores de riesgo / Incidence of pressure ulcers in admitted patients with risks factors

Las úlceras por presión (UP)son un importante problema de salud en pacientes hospitalizados. La epidemiología de este problema es poco conocida a nivel nacional. El objetivo del trabajo es conocer la incidencia de UP en un grupo seleccionado de pacientes que presentan factores de riesgo para esta patología. Material y método: estudio de una cohorte de pacientes que ingresan al hospital los cuales se dividen en tres grupos (grupo 1: ulceración al ingreso, grupo 2: con enfermedad invalidante, grupo 3: dos o más factores de riesgo, sin invalidez). Estos tres grupos de pacientes son examinados diariamente durante su hospitalización, identificando el momento, sitio de aparición, etapa y evolución de las UP. Resultados de un total de 1831 ingresos en tres meses, un grupo de 300 pacientes son seguidos durante un promedio de 15,7 días de hospitalización cada uno (rango 5 a 71), estableciéndose una incidencia global de UP de 28 por ciento (84 de 300). El tiempo promedio de aparición de UP fue 4,7 días. La incidencia de UP fue mayor en los grupos 1 y 2 versus el grupo 3 (p<0,05), así como la incidencia de UP severas (etapas 3 y 4). Los pacientes en el grupo 1 tuvieron una evolución peor que los grupos 2 y 3, con un 57 por ciento de empeoramiento de sus UP. No hubo diferencia de UP en los distintos servicios clínicos. Los resultados permiten establecer una base epidemiológica conocida en nuestro medio hospitalario para planificar estrategias de prevención desde el ingreso de los pacientes al hospital.