The effect of hyperbaric oxygen therapy on treatment of wound complications after oral, pharyngeal and laryngeal salvage surgery.

INTRODUCTION: Radiation therapy alone, or combined with chemotherapy, are both used for cancer in the head and neck. This can lead to damage of tissue cells and vasculature. Surgery in such compromised tissues has increased complication rates, because wound healing with angiogenesis and fibroplasias requires normal cell growth conditions. Hyperbaric oxygen therapy raises oxygen levels in hypoxic tissue, stimulates angiogenesis and fibroplasia. In this report, we review the clinical value of hyperbaric oxygen therapy for major wounds that had shown no signs of healing as well as fistulas after salvage surgery in patients treated with (chemo)radiation of the head and neck regions. METHODS: In this retrospective study, 16 patients with soft-tissue wounds without signs of healing after salvage surgery, after radiation, and most after chemotherapy were treated in the head and neck regions with hyperbaric oxygen therapy. The patients were treated by HBO2, 2.5 bars 90 minutes daily, usually 20 treatments. RESULTS: The healing processes seemed to be initiated and accelerated by HBO2. Fourteen of the 16 patients healed completely. There were no life-threatening complications. CONCLUSION: Radiotherapy and combined chemoradiation therapy leads to damage of tissue cells and vasculature. Salvage surgery in such tissues has an increased complications rate, because wound healing requires angiogenesis and fibroplasias, all of which are jeopardized. Hyperbaric oxygen therapy raises oxygen levels in hypoxic tissue, stimulates angiogenesis and fibroplasias and is an effective and powerful treatment for postoperative wounds in oral, pharyngeal and laryngeal carcinomas surgery.

Fas/FasL expression in tumor biopsies: a prognostic response factor to fluoropyrimidines?

Various studies suggested that cytotoxicity induced by 5-fluorouracil (5-FU) is an apoptotic mechanism possibly mediated by the Fas/FasL system. In this preliminary work, we studied retrospectively the role the Fas/FasL expression as a predictive response factor with fluoropyrimidine-based chemotherapies. We developed a real-time PCR method for measuring Fas and FasL expression in various biopsies from patients treated with a FUFOL-like protocol. No correlation was found between Fas or FasL expression and overall survival or partial response. However, the PCR assay was simple and convenient to use for quantitation of Fas/FasL in tumor biopsies.

Color stability of commercial anthocyanin-based extracts in relation to the phenolic composition. Protective effects by intra- and intermolecular copigmentation.

Anthocyanin extracts are increasingly used as food ingredients. A current challenge is to maintain their color properties. The stability of some colorants has been studied in sugar and non-sugar drink models at three pH values (3, 4, and 5) under thermal and light conditions simulating rapid food aging. At a given pH, color stability mainly depends on the structures of anthocyanins and of colorless phenolic compounds. Colorants rich in acylated anthocyanins (purple carrot, red radish, and red cabbage) display great stability due to intramolecular copigmentation. The protection of red chromophore is higher for diacylated anthocyanins in red radish and red cabbage. For colorants without acylated anthocyanins (grape-marc, elderberry, black currant, and chokeberry), intermolecular copigmentation plays a key role in color protection. Colorants rich in flavonols and with the highest copigment/pigment ratio show a remarkable stability. By contrast, catechins appear to have a negative effect on red colorants, quickly turning yellowish in drink models. This effect is more pronounced when the pH is increased. Finally, color does not seem to be greatly influenced by the addition of sugar.

Interspecies variability and drug interactions of clozapine metabolism by microsomes.

Cytochrome P450 expression in liver is influenced by several factors, including species, sex and strain. We compared metabolism formation of clozapine in different species (rat, mouse, guinea-pig, dog, monkey and man) so as to choose between species to further validate interaction studies. Liver microsomes of male and female Sprague-Dawley rats, hairless rats, OF1 mice, Balb C mice and Dunkin-Hartley albino guinea-pigs, male beagle dogs, male cynomolgus monkeys and man were used to investigate in vitro metabolism of clozapine. This process was dependent on the presence of NADPH and on the presence of microsome protein. In addition, we observed the formation of desmethyl- and N-oxide metabolites, with the rate of formation of each of these compounds varying with species, sex and strain of microsomes incubated. The desmethyl- and N-oxide metabolites formed were statistically greater in male than in female rats, mice in the two strains studied, as well as for the guinea-pigs. Levels of desmethyl clozapine formed were high for the rats and no significant difference in clozapine biotransformation was observed between Sprague-Dawley and hairless rats. For man, the formation of metabolites of clozapine was comparable with guinea-pig, dog and monkey. In addition, we screened the effect of 52 molecules, representative of 11 different therapeutic classes, on the metabolism of clozapine by rat liver microsomes. We found that most of the calcium channel blockers (diltiazem, felodipine, isradipine, lacidipine, nicardipine and nitrendipine), antifungals (ketoconazole, miconazole) and two anticancer drugs (paclitaxel, teniposide) caused more than 50% inhibition of clozapine metabolism in vitro. The extent of inhibition was increased in a concentration-dependant manner. Complementary clinical and pharmacokinetic studies should be performed to confirm these results.

[Early adjuvant intraportal chemotherapy with 5-fluorouracil after hepatic resection of colorectal metastasis: a preliminary clinical and pharmacokinetic study]. / Chimiothérapie intraportale adjuvante précoce par le 5-fluoro-uracile après resection hépatique pour métastases d'origine colorectale: étude préliminaire clinique et pharmacocinétique.

Intraportal continuous infusion of 5-FU (600 mg/m2/24 h during 7 days) was administered in the immediate postoperative course of 6 consecutive patients with colorectal metastases resected for cure (one segmentectomy and 5 nonanatomical local resections). One month later, a systemic continuous infusion of 5-FU was delivered at the same dose. The tolerance of intraportal chemotherapy was good despite 2 patients with mild digestive toxicity. The plasma concentrations of both unchanged 5-FU and 5,6-dihydro-5-FU (the primary metabolite of 5-FU), were determined in 2 patients using Gas Chromatography--Mass Spectrometry. The 5-FU clearance was higher after intraportal infusion than after systemic infusion (x 1.5 to 3). Hepatic extraction was variable (0.32-0.70) and lower than in reported experimental data on dogs (0.90-0.99). 5,6-dihydro-5-FU concentrations were constantly higher than 5-FU concentrations in plasma. The patient with lower hepatic extraction had the higher 5,6-dihydro-5-FU plasma concentrations. These findings suggest a predominant extrahepatic formation of plasmatic 5,6-dihydro-5-FU.

Long-lasting insomnia induced by preoptic neuron lesions and its transient reversal by muscimol injection into the posterior hypothalamus in the cat.

In order to analyse the role of the anterior hypothalamus in the regulation of the sleep-waking cycle we made bilateral neuronal lesions at different levels of the anterior hypothalamus in cats, by means of microinjections of a cell-specific neurotoxin:ibotenic acid. These lesions resulted in severe insomnia in eight cats. This insomnia was characterized by a large decrease or even disappearance of paradoxical sleep and deep slow wave sleep and, to a lesser extent, by a decrease of light slow wave sleep, for 2-3 weeks. In the other five animals, we observed a large reduction of deep slow wave sleep (0-40% of control level), but a less intensive decrease of time spent in paradoxical sleep (50-75% of control level) and no marked effect on light slow wave sleep. During the first 3-6 postoperative days we also noticed hyperthermia in all cats; thereafter, the animals presented only a slight increase in brain temperature which did not appear to trigger the sleep impairment. Histological analysis of the different lesions revealed that the insomnia could be attributed to neuronal cell body destruction in the mediobasal part of the anterior hypothalamus covering; the medial preoptic area and a narrow portion of the lateral preoptic area as well as a restricted part of the anterior hypothalamic nucleus. In order to investigate the putative role of the posterior hypothalamic structures in the mechanism of insomnia after lesion of the mediobasal preoptic area neurons we injected an agonist of GABA into the ventrolateral part of the posterior hypothalamus to locally depress the neuronal activity. The bilateral intracerebral microinjection of muscimol (0.5-5 micrograms) induced a transient intensive hypersomnia (slow wave sleep and paradoxical sleep). These findings indicate that neuronal cell loss in the mediobasal preoptic area induced a long lasting insomnia. Thus, it may be hypothesized that the integrity of this structure is necessary for sleep appearance. Finally, our data are in keeping with an intrahypothalamic regulation of the sleep-waking cycle.

Reversibility of para-chlorophenylalanine-induced insomnia by intrahypothalamic microinjection of L-5-hydroxytryptophan.

Para-chlorophenylalanine, a blocker of serotonin biosynthesis by inhibiting tryptophan hydroxylase, induced total insomnia which was accompanied in cat by a permanent discharge of ponto-geniculo-occipital activity. L-5-Hydroxytryptophan microinjection (1-4 micrograms/0.5 microliters) in the anterior hypothalamus 72 h after para-chlorophenylalanine administration, restored both slow wave sleep and paradoxical sleep with variable latencies for each state of sleep. On the contrary, ponto-geniculo-occipital activity was never suppressed. The hypnogenic effects of L-5-hydroxytryptophan were always followed by a return of the para-chlorophenylalanine-induced insomnia. On the other hand, the temperature recording did not show any alteration of the cerebral temperature after para-chlorophenylalanine treatment but the subsequent L-5-hydroxytryptophan microinjection was followed by hyperthermia. Using immunohistochemistry for serotonin after intrahypothalamic L-5-hydroxytryptophan microinjection in parachlorophenylalanine-pretreated cat, we defined a restricted region of the anterior hypothalamus possibly responsible for the hypnogenic effect. This region included the lateral hypothalamus and the anterior hypothalamic area. It is suggested that the reversible hypersomnia after L-5-hydroxytryptophan microinjection in the anterior hypothalamus in para-chlorophenylalanine-pretreated cat is due to a neurohormonal action of serotonin: serotonin could act upon the anterior hypothalamus which secondarily inhibits a waking system located in the ventrolateral hypothalamus leading to the appearance of paradoxical sleep.

[Insomnia following a lesion of the paramedial preoptic area is reversible by inactivation of the posterior hypothalamus in the cat]. / L'insomnie consécutive à la lésion de la région préoptique paramédiane est réversible par inactivation de l'hypothalamus postérieur chez le chat.

The bilateral intratissular injection of muscimol, an agonist of gamma amino butyric acid (GABA), induced a transient hypersomnia (slow wave sleep and paradoxical sleep) in an insomniac cat whose paramedial preoptic area had been previously bilaterally destroyed.