Fluid volume kinetics of dilutional hyponatremia; a shock syndrome revisited

OBJECTIVE: To evaluate whether the pathophysiology of shock syndromes can be better understood by comparing central hemodynamics with kinetic data on fluid and electrolyte shifts. METHODS: We studied the dilutional hyponatremic shock that developed in response to overhydration with electrolyte-free irrigating fluid - the so-called ‘transurethral resection syndrome' - by comparing cardiac output, arterial pressures, and volume kinetic parameters in 17 pigs that were administered 150 ml/kg of either 1.5% glycine or 5% mannitol by intravenous infusion over 90 minutes. RESULTS: Natriuresis appeared to be the key factor promoting hypovolemic hypotension 15-20 minutes after fluid administration ended. Excessive sodium excretion, due to osmotic diuresis caused by the irrigant solutes, was associated with high estimates of the elimination rate constant (k10) and low or negative estimates of the rate constant describing re-distribution of fluid to the plasma after translocation to the interstitium (k21). These characteristics indicated a high urinary flow rate and the development of peripheral edema at the expense of plasma volume and were correlated with reductions in cardiac output. The same general effects of natriuresis were observed for both irrigating solutions, although the volume of infused 1.5% glycine had a higher tendency to enter the intracellular fluid space. CONCLUSION: Comparisons between hemodynamics and fluid turnover showed a likely sequence of events that led to hypovolemia despite intravenous administration of large amounts of fluid. .

Efecto antinociceptivo de estriol y Glicina max l. (soya) en ratas ovariectomizadas / Antinociceptive effect of estriol and Glicina max l. (soya) in ovariectomized rats

Objetivo: Demostrar el efecto protector del estriol y Glicina max L. (soya) frente al dolor nociceptivo, en ratas ovariectomizadas. Diseño: Estudio experimental. Lugar: Bioterio de la Facultad de Medicina, Universidad Nacional Mayor de San Marcos. Material biológico: Ratas hembras albinas Holtzman de 2,5 a 3 meses de edad. Métodos: Las 29 ratas fueron agrupadas aleatoriamente: grupo 1 (n=8), no ovariectomizadas, tratadas con solución salina (0,1 mL/kg); grupo 2 (n=7), ovariectomizadas y tratadas con solución salina (0,1 mL/kg); grupo 3 (n=7), ovariectomizadas y tratadas con estriol (0,2 mg/kg); grupo 4 (n=7), ovariectomizadas y tratadas con Glycine max L. (60 mg/kg). Se realizó una prueba basal de dolor térmico en el hornillo a todos los animales, así como tres días después del tratamiento farmacológico. Principales medidas de resultados: Se usó el porcentaje de eficiencia antinociceptiva máxima (porcentaje EAM). Resultados: Se encontró que el porcentaje EAM fue mayor en el grupo de ratas no ovariectomizadas (1,6 por ciento) que en el grupo de las ovariectomizadas (0,8 por ciento). Por otro lado, el porcentaje EAM en ratas ovariectomizadas con solución salina (0,8 por ciento) fue menor al compararlo con el grupo de las tratadas con estriol (5,8 por ciento); así también, el porcentaje EAM del grupo de ovariectomizadas tratadas con Glicina max L. (4,2 por ciento) fue superior al grupo de ovariectomizadas tratadas con solución salina (0,8 por ciento), pero esta no fue superior a las del grupo tratadas con estriol. Conclusiones: El estriol y la Glicina max L. ejercieron un papel protector frente al dolor nociceptivo térmico en ratas ovariectomizadas.

Objective: To determine the protective effect of estriol and Glycine max L. (soybean) compared to nociceptive pain in ovariectomized rats. Design: Experimental study. Setting: Faculty of Medicine bioterium, Universidad Nacional Mayor de San Marcos, Lima, Peru. Biological material: Holtzman albino female rats 2,5 to 3 months of age. Methods: The 29 rats were grouped randomly: group 1 (n = 8) non ovariectomized rats treated with saline (0.1 mL/kg); group 2 (n = 7) ovariectomized rats treated with saline (0.1 mL / kg); group 3 (n = 7) ovariectomized rats treated with estriol (0.2 mg/kg); group 4 (n = 7) ovariectomized rats treated with Glycine max L. (60 mg/kg). We determined baseline hotplate thermal pain as well as three days after treatment. Main outcome measures: Antinociceptive maximum efficacy (percentage AME). Results: We found that percentage EAM was higher in the non ovariectomized rats group (1.6 per cent) than in the ovariectomized group (0.8 per cent). Furthermore, the percentage of EAM in ovariectomized rats treated with saline (0.8 per cent) compared with the group treated with estriol (5.8 per cent) and also the percentage of EAM in the Glycine max L. group (4.2 per cent) was higher than in the ovariectomized group treated with saline (0.8 per cent) but not higher than the group treated with estriol. Conclusions: Estriol and Glycine max L. have protective role against thermal nociceptive pain in ovariectomized rats.

Efectos de la glicina sobre los trastornos de conducción del nervio auditivo en pacientes diabéticos tipo 2 con otoneuropatía / Effects of glycine on auditory evoked potentials among diabetic patients with auditory pathway neuropathy

Background: Glycine inhibits the formation of advanced glycation end products that may cause central and peripheral neuronal damage, affecting also the auditory nerve. Aim: To evaluate the effect of glycine on auditory nerve conduction and hearing level among patients with type 2 diabetes mellitus and auditory neuropathy. Material and Methods: Twenty grams of oral glycine per day were administered during 6 months to 28 type 2 diabetic patients aged 58 ± 6 years, with auditory pathway neuropathy. Hearing tests and evoked otoacustic potentials were performed regularly. Fifteen diabetic patients aged 49 ± 8 years, without auditory nerve neuropathy did not receive glycine and were followed as a control group. Results: Among patients receiving glycine, a significant improvement in left ear audiometry at 125, 250 and 500 Hz and right ear audiometry at 500 Hz, was observed. Waves I, III and V (p= 0.02) of evoked otoacustic potentials improved significantly in the left ear and wave I in the right ear. Among controls, waves V and III of evoked otoacoustic potentials had a significant impairment in the left ear. Conclusions: There was an improvement in auditory evoked potentials in patients receiving glycine and an impairment in untreated control patients.

Transurethral resection of prostate: a comparison of standard monopolar versus bipolar saline resection

INTRODUCTION: Transurethral resection syndrome is an uncommon but potentially life threatening complication. Various irrigating solutions have been used, normal saline being the most physiological. The recent availability of bipolar cautery has permitted the use of normal saline irrigation. MATERIAL AND METHODS: In a randomized prospective study, we compared the safety and efficacy of bipolar cautery (using 0.9 percent normal saline irrigation) versus conventional monopolar cautery (using 1.5 percent glycine irrigation). Pre and postoperative hemoglobin (Hb) and hematocrit values were compared. Hemodynamics and arterial oxygen saturation were monitored throughout the study. Safety end points were changes in serum electrolytes, osmolarity and Hb/PCV (packed cell volume). Efficacy parameters were the International Prostate Symptom Score (IPSS) and Qmax (maximum flow rate in mL/sec) values. RESULTS: Mean preoperative prostate size on ultrasound was 60 ± 20cc. Mean resected weight was 17.6 ± 10.8 g (glycine) and 18.66 ± 12.1 g (saline). Mean resection time was 56.76 ± 14.51 min (glycine) and 55.1 ± 13.3 min (saline). The monopolar glycine group showed a greater decline in serum sodium and osmolarity (4.12 meq/L and 5.14 mosmol/L) compared to the bipolar saline group (1.25 meq/L and 0.43 mosmol/L). However, this was not considered statistically significant. The monopolar glycine group showed a statistically significant decline in Hb and PCV (0.97 gm percent, 2.83, p < 0.005) as compared to the bipolar saline group (0.55 gm percent and 1.62, p < 0.05). Patient follow- up (1,3,6 and 12 months postoperatively) demonstrated an improvement in IPSS and Qmax in both the groups. CONCLUSION: We concluded that bipolar transurethral resection of prostate is clinically comparable to monopolar transurethral resection of prostate with an improved safety profile. However, larger number of patients with longer follow up is essential.

Glutamate-N-methyl-D-aspartate receptor modulation and minocycline for the treatment of patients with schizophrenia: an update: [review]

Growing consistent evidence indicates that hypofunction of N-methyl-D-aspartate (NMDA) transmission plays a pivotal role in the neuropathophysiology of schizophrenia. Hence, drugs which modulate NMDA neurotransmission are promising approaches to the treatment of schizophrenia. The aim of this article is to review clinical trials with novel compounds acting on the NMDA receptor (NMDA-R). This review also includes a discussion and translation of neuroscience into schizophrenia therapeutics. Although the precise mechanism of action of minocycline in the brain remains unclear, there is evidence that it blocks the neurotoxicity of NMDA antagonists and may exert a differential effect on NMDA signaling pathways. We, therefore, hypothesize that the effects of minocycline on the brain may be partially modulated by the NMDA-R or related mechanisms. Thus, we have included a review of minocycline neuroscience. The search was performed in the PubMed, Web of Science, SciELO, and Lilacs databases. The results of glycine and D-cycloserine trials were conflicting regarding effectiveness on the negative and cognitive symptoms of schizophrenia. D-serine and D-alanine showed a potential effect on negative symptoms and on cognitive deficits. Sarcosine data indicated a considerable improvement as adjunctive therapy. Finally, minocycline add-on treatment appears to be effective on a broad range of psychopathology in patients with schizophrenia. The differential modulation of NMDA-R neurosystems, in particular synaptic versus extrasynaptic NMDA-R activation and specific subtypes of NMDA-R, may be the key mediators of neurogenesis and neuroprotection. Thus, psychotropics modulating NMDA-R neurotransmission may represent future monotherapy or add-on treatment strategies in the treatment of schizophrenia.

Efetividade de diferentes estratégias de intervenção com ferro nos níveis de hemoglobina e ferritina em escolares de Teresina, Piauí, Brasil / Effectiveness of different iron supplementation strategies on hemoglobin and ferritin levels among schoolchildren in Teresina, Piauí State, Brazil

O estudo avaliou o efeito das intervenções com sulfato ferroso e com ferro bisglicina quelato nas concentrações de hemoglobina e ferritina sérica em escolares de 7-11 anos, de ambos os sexos, de Teresina, Piauí, Brasil. Foi desenvolvido ensaio clínico-comunitário, randomizado, envolvendo 138 escolares, com níveis de hemoglobina < 11,5g/dL, alocados, individualmente, em dois grupos de tratamento. Um grupo (n = 71) recebeu 40mg de sulfato ferroso, uma vez/semana, e o outro (n = 67) 3,8mg de ferro bisglicina quelato, fracionados em biscoitos consumidos três vezes/semana, durante oito semanas. Houve um incremento (p < 0,01) médio, nas concentrações de hemoglobina, de 1,1g/dL entre os escolares que receberam sulfato ferroso e de 0,9g/dL para aqueles que receberam ferro bisglicina quelato, embora sem diferença (p > 0,05) na comparação intergrupos. Nenhum impacto foi observado (p > 0,05) nas reservas corporais de ferro. Entretanto, escolares que apresentaram depleção das reservas corporais de ferro (< 15ng/mL), no início dos tratamentos, tiveram aumento (p < 0,01) nas concentrações médias de ferritina sérica, após a intervenção, embora com efeito similar (p > 0,05) entre os grupos de tratamento. Os resultados confirmam a efetividade das intervenções e ratificam o uso do esquema semanal com sulfato ferroso e com ferro bisglicina quelato no tratamento da deficiência do mineral e da anemia ferropriva.

This study evaluated the effectiveness of supplementation with ferrous sulfate and iron bis-glycinate chelate on hemoglobin and serum ferritin levels among schoolchildren (7-11 years) of both sexes. A randomized community-based trial including 138 anemic children (hemoglobin < 11.5g/dL) was conducted in Teresina, Piauí State, Brazil. Children were assigned to two treatment groups on an individual basis. One group (n = 71) received 40mg iron as ferrous sulfate once weekly and the other group (n = 67) received 3.8mg of iron bis-glycinate chelate-enriched cookies, 3x/week, for 8 weeks. The interventions showed a significant increase (p < 0.01) in hemoglobin levels (1.1g/dL) for children who received ferrous sulfate and 0.9g/dl in those who received iron bis-glycinate chelate, although not significant in the inter-group comparison (p > 0.05). No effect was observed on body iron for either intervention (p > 0.05). Children with depleted iron stores (< 15ng/mL) at the beginning of interventions showed increased serum ferritin concentrations after 8 weeks (p < 0.01), although no difference between treatments (p > 0.05) was observed. The results confirm the effectiveness of the iron supplementation interventions and corroborate the use of iron salts or ferrous bisglycinate chelate on a weekly basis to overcome iron deficiency and anemia.

Tryptophan and tyrosine catabolic pattern in neuropsychiatric disorders.

Catabolism of tryptophan and tyrosine in relation to the isoprenoid pathway was studied in neurological and psychiatric disorders. The concentration of trytophan, quinolinic acid, kynurenic acid, serotonin and 5-hydroxyindoleacetic acid was found to be higher in the plasma of patients with all these disorders; while that of tyrosine, dopamine, epinephrine and norepinephrine was lower. There was increase in free fatty acids and decrease in albumin (factors modulating tryptophan transport) in the plasma of these patients. Concentration of digoxin, a modulator of amino acid transport, and the activity of HMG CoA reductase, which synthesizes digoxin, were higher in these patients; while RBC membrane Na+-K+ ATPase activity showed a decrease. Concentration of plasma ubiquinone (part of which is synthesised from tyrosine) and magnesium was also lower in these patients. No morphine could be detected in the plasma of these patients except in MS. On the other hand, strychnine and nicotine were detectable. These results indicate hypercatabolism of tryptophan and hypocatabolism of tyrosine in these disorders, which could be a consequence of the modulating effect of hypothalamic digoxin on amino acid transport.