Effects of intravenously administered hypertonic urea solution

Summary and Conclusions In 12 patients with increased intracranial pressure, caused by an expanding process, a hypertonic urea solution was intravenously administered during a craniotomy. At different times before, during and after the operation, the electrolytes, urea, glucose and total protein values were determined in various body fluids and tissues.This study disclosed that the urea administered was distributed through both the intracellular and the extracellular space after 20 minutes. The values of the electrolytes, except the calcium, in the extracellular fluid remained constant after administration of the urea solution; the total protein value, however, showed a considerable decrease.It was established that the blood-brain barrier plays no appreciable role in the mechanism of action of hypertonic urea solutions in dehydrating the brain tissue; the blood-C. S. P. and brain-C. S. F. barriers may do.

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Zusammenfassung Bei 12 Patienten mit intrakranieller Drucksteigerung infolge eines raumbeengenden Prozesses wurde Harnstofflösung intravenös während der Schädeleröffnung gegeben. Zu verschiedenen Zeitpunkten vor, während und nach der Operation wurden Elektrolyt, Harnstoff, Glukose und Gesamteiweiß quantitativ bestimmt und zwar sowohl in verschiedenen Körperflüssigkeiten wie auch in Geweben.Die Untersuchungen ergaben, daß der verabfolgte Harnstoff in 20 Minuten sich sowohl auf den intrazellulären, wie den extrazellulären Raum verteilt hat. Die Elektrolytwerte, mit Ausnahme von Kalzium, blieben nach der Harnstoffinfusion in den extrazellulären Flüssigkeiten unverändert, der Gesamteiweißwert nahm dagegen beträchtlich ab.Es wurde festgestellt, daß die Bluthirnschranke keine wesentliche Rolle für die entwässernde Wirkung des Harnstoffes auf das Hirngewebe spielt, während die Blut-Liquor-Schranke und die Hirn-Liquor-Schranke vielleicht von Bedeutung sind.

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Resumen Después de una craniectomía se administró una solución de urea hipertónica por via intravenosa a 12 pacientes que presentaban una presión intracraneal creciente a causa de una exposición de la hipófisis. Periódicamente, antes, durante y después de la operación se determinaron los valores de los electrolitos, de la urea, de la glucosa y de las proteinas totales en los diferentes líquidos y tejidos del organismo.Este estudio demostróque la urea administrada se distribuia a través del espacio intra y extracelular al cabo de 20 minutos. Los valores de los electrolitos, excepto el calcio, permanecieron constantes en el líquido extracelular después de la administración de la solución de urea; el valor de las proteinas totales, sin embargo, mostró un descenso considerable.Se concluyó que la barrera hemato-encefálica no juega ningún papel apreciable en los mecanismos de acción de las soluciones de urea hipertónica en la deshidratación del tejido cerebral; tal vez lo juegue en las barreras sangre-liquido cofalo-raquídeo y cerebro-líquido cefalo-raquídeo.

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Résumé Lors d'une craniotomie, une solution d'urée hypertonique fut administrée par voie intraveineuse chez 12 patients présentant une pression intracrânienne grandissante causée par une expansion de l'apophyse. De temps en temps, avant, pendant et après l'opération, les valeurs des électrolytes, de l'urée, du glucose et de la protéine totale étaient déterminées dans les différents liquides et tissus du corps.Cette étude démontra que l'urée administrée était distribuée à travers l'espace intra et extraecllulaire au bout de 20 minutes. Les valeurs des électrolytes, excepté le calcium, demeurèrent constantes dans le liquide extracellulaire après l'administration de la solution d'urée; la valeur de la protéïne totale, pourtant, montrait une baisse considérable.Il fut établi que la barrière hémato-encéphalique ne joue aucun rôle appréciable dans le mécanisme d'action des solutions d'urée hypertonique dans la déshydratation du tissu cérébral; les barrières sang-liquide céphalorachidien et cerveau-liquide céphalo-rachidien, peut-être.

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Riassunto In 12 pazienti con ipertensione endocranica, causata da un processo espansivo, è stata somministrata durante la craniotomia dell'urea in soluzione ipertonica per via venosa. A diversi tempi prima, durante e dopo l'intervento, sono stati dosati gli elettroliti, l'urea, il glueosio e le proteine totali in vari fluidi e tessuti corporei. Queste ricerche hanno evidenziato che l'urea viene distribuita tra spazio intracellulare ed extracellulare in 20 minuti. I livelli degli elettroliti, eccetto il calcio, rimangono costanti nel liquido extracellulare dopo la somministrazione di urea, i valori della proteinemia totali invece mostrano una notevole diminuizione.E' stato stabilito che la barriera emato-cerebrale non gioca alcun ruolo apprezzabile nel meccanismo d'azione dell'urea ipertonica nel disidratare il tessuto cerebrale; un ruolo importante potrebbe essere inveoe giocato dalla barriera emato-liquorale e tra liquor e sistema nervoso.

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This study was supported by a grant from the Netherlands Organization for the Advancement of Pure Research (Nederlandse Organisatie voor Zuiver-Wetenschappelijk Onderzoek, Z. W. O.).     

Induction of rat hepatic and intestinal glutathione s-transferases and glutathione by dietary naturally-occurring anticarcinogens

Effects of dietary naturally occurring anticarcinogens; quercetin, flavone, ellagic acid, ferulic acid, tannic acid, curcumin, coumarin, alpha-angelicalactone, fumaric acid and Brussels sprouts on male Wistar rat hepatic and intestinal (i) glutathione S-transferases (GST) enzyme activity, (ii) GST isozyme levels and (iii) glutathione (GSH) content were investigated. GST enzyme activity was significantly increased by all anticarcinogens tested, except fumaric acid, at least at one of the five sites investigated: proximal, middle, distal small intestine, large intestine and liver. Only alpha-angelicalactone gave an enhanced GST enzyme activity at all five sites. Large intestinal GST enzyme activity was increased only by quercetin (175%) and alpha-angelicalactone (138%). Concomitant changes in GST isozyme levels occurred. Class alpha GSTs were induced in 50% of the cases, especially in liver and upper parts of the intestine by quercetin, flavone, coumarin and alpha-angelicalactone. GST class pi levels were enhanced only at one site by quercetin, coumarin and alpha-angelicalactone. GST class mu changed in 14% of the cases, most profoundly in proximal and middle small intestine by flavone, coumarin and alpha-angelicalactone. Tannic acid and fumaric acid gave a significant raise in class alpha GSTs at almost all sites, whereas overall GST enzyme activity hardly changed. GSH was increased at various sites in 14% of the cases by Brussels sprouts, quercetin, flavone and alpha-angelicalactone. These data demonstrate that most anticarcinogens, in particular flavone, coumarin and alpha-angelicalactone, enhance GST activity in liver and intestine, mainly by induction of class alpha and mu isozymes.     

Comparative study of a foam mattress and a water mattress

In order to determine the effectiveness of high-quality foam replacement mattresses in the treatment of pressure ulcers, one such mattress (TheraRest) was compared with a water mattress (Secutex). One hundred and twenty nursing home patients with pressure ulcers were randomised into two groups and nursed on one of the mattresses for four weeks. After four weeks, 45% of the patients using the foam mattress were completely healed, compared with 48.3% of those using the water mattress. This difference is not significant. Since high-quality foam mattresses are cheaper in the long term than water mattresses, and are easier for nursing staff to manage, it is suggested that these mattresses are preferable.     

Factors causing differences in voiding parameters between conventional and ambulatory urodynamics

Voiding parameter values measured with ambulatory urodynamic monitoring (AM) are generally found to be different from those measured with conventional cystometry (CMG). The reason for this is unclear, but might be related to differences in the voided volume. To verify this hypothesis, we compared voidings from female patients at an initial bladder volume that was close to the modal volume (that is, the volume most often voided by the patient as derived from frequency/volume charts) with voidings at maximum cystometric capacity during a routine video urodynamic examination. A first group of 35 patients voided at the modal volume before they did at capacity. The order was reversed in a second group of 12 patients. The dependence of the voiding parameters on the voided volume and the order of the measurements were examined. It was found that the maximum flow rate depended significantly on the voided volume, but the associated detrusor pressure did not. Urethral resistance and bladder contraction strength were not volume dependent either. It was concluded that the differences between AM and CMG cannot be explained from possible differences in the voided volume. Received: 23 August 1999 / Accepted: 16 December 1999     

Superior vena cava obstruction caused by radiation induced venous fibrosis

Superior vena cava syndrome is most often caused by lung carcinoma. Two cases are described in whom venous obstruction in the superior mediastinum was caused by local vascular fibrosis due to radiotherapy five and seven years earlier. The development of radiation injury to greater vessels is discussed, together with the possibilities for treatment of superior vena cava syndrome.     

Transforming growth factor-beta plasma dynamics and post-irradiation lung injury in lung cancer patients.

PURPOSE: To investigate the relevance of transforming growth factor-beta (TGF-beta) dynamics in plasma for identification of patients at low risk for developing pneumonitis as a complication of thoracic radiotherapy (RT). PATIENTS AND METHODS: Non-small cell lung cancer patients undergoing conventional RT were included in the prospective study. Concentrations of TGF-beta were measured in the patients' plasma prior to and weekly during 6 weeks of RT. The incidence of symptoms of early post-irradiation lung injury, i.e. symptomatic radiation pneumonitis, was correlated with TGF-beta parameters. RESULTS: Forty-six patients were included in the study. Eleven patients (24%) developed symptomatic radiation pneumonitis. Absolute TGF-beta plasma levels did not differ between the groups of patients without or with pneumonitis. However, patients who developed pneumonitis tended to show increases in TGF-beta levels in the middle of the RT course relative to their pre-treatment levels while TGF-beta plasma levels of patients who did not develop pneumonitis tended to decrease over the RT treatment. The difference in the relative TGF-beta dynamics between the groups reached marginal significance in the third week of the treatment (P = 0.055) but weakened towards the end of the RT course. The utility of TGF-beta testing was evaluated at each RT week based on the test's ability to yield more accurate estimate of complication probability in an individual patient compared to empirically expected probability in similar group of patients. The ratio of TGF-beta level at week 3/week 0 being <1 showed an ability to improve the prediction of freedom from pneumonitis, yet with a large degree of uncertainty (wide confidence intervals). The accuracy of prediction deteriorated at later time points (weeks 4, 5 and 6) rendering the end-RT ratios without predictive power. CONCLUSIONS: We observed a trend of plasma TGF-beta concentration to decrease below the pre-treatment value during the RT treatment in patients who did not develop pulmonary complications after the RT treatment. However, this trend was not consistent enough to warrant safe decision-making in clinical setting.