The importance of preconception Hcy testing: identification of a folate trap syndrome in a woman attending an assisted reproduction program

Methylation is a ubiquitous and permanent key biochemical process playing a major role in gametogenesis and embryogenesis in relation to epigenetics and imprinting. Methylation relies on a unique cofactor S-Adenosyl Methionine: SAM. Release of the methyl group onto target molecules is followed by liberation of S-Adenosyl Homocysteine (SAH), and then homocysteine (Hcy), both potent inhibitors of the methylation process. Defective recycling of homocysteine, leading to Hyperhomocysteinemia, is mainly due to reduced activity of MTHFR (Methylene TetraHydroFolate Reductase). However, we described here, in a woman attending an ART program, a rather rare syndrome: The Folate trap syndrome. Due to vitamin B12 deficiency (malabsorption), Hcy cannot be recycled to methionine by the methionine synthase. Transmethylation activity is weak and leads to Hhcy (Hyperhomocysteinhemia). Her Hhcy, over 16µM, was resistant to 5MTHF (5 Methyltetrahydrofolate) associated with a support of the one carbon cycle, a classical efficient treatment for elevated homocysteine. Treatment with Methylcobalamine (associated with adenosyl Cobalamine) allowed a Hcy drop down to 10 µM. Knowing the pleiotropic negative impact of Hcy on gametes, embryos and pregnancy in general, we strongly recommend a Hcy dosage in both members of couples seeking treatment for pregnancy.

T677T Methylenetetrahydrofolate Reductase Single Nucleotide Polymorphisms Increased Prevalence in a Subgroup of Infertile Patients with Endometriosis

<b><i>Background:</i></b> Approximately 10% (190 million) of women worldwide are affected by endometriosis, ectopic deposits of endometrial tissue that create a major source of pain that affects lifestyle and reproductive function. The pathogenesis of endometriosis is an estrogen-dependent inflammatory process, influenced/catalyzed by oxidative stress and consequently defective methylation, with biochemical features centered around the folate and one-carbon cycles. We aimed to determine whether a link could be found between the two major methylenetetrahydrofolate reductase single nucleotide polymorphisms (MTHFR SNPs), c.677C&gt;T and c.1298A&gt;C, involved in methylation process/epigenetic marking failures, and endometriosis. <b><i>Material and Methods:</i></b> We studied a population of 158 patients in a group of &gt;1500 referred for treatment of infertility. All the patients had experienced &gt;2 failed assisted reproductive technology cycles and/or &gt;2 miscarriages, a classical cohort for investigation in our group. Patients with endometriosis had at least stage 2+ disease confirmed by laparoscopy. <b><i>Results:</i></b> The prevalence of the homozygous c.677C&gt;T isoform is doubled in the endometriosis group, 21.5% versus 10.2% in the non-endometriosis group (<i>p</i> &gt; 0.01). Symmetrically, the percentage of patients in the endometriosis group with the wild type MTHFR significantly decreased by one-half (8.2%-17.2%) in the non-endometriosis group (<i>p</i> &lt; 0.001). <b><i>Conclusion:</i></b> Determination of MTHFR c.677C&gt;T should not be overlooked in patients with harmful endometriosis affecting their fertility. As folates metabolism is impaired in these MTHFR SNPs carrier patients, co-treatment with 5-methyl folate may constitute a successful (co)-treatment modality.

[Importance of the determination of MTHFR SNPs (Methylene Tetrahydrofolate Reductase Single Nucleotide Polymorphisms) in couple infertility]

OBJECTIVE

MTHFR SNPs (Methylene Tetrahydrofolate reductase Single Nucleotide polymorphisms) are biochemical modifications decreasing the capacity to form 5 MTHF 5 methyltetrahydrofolate (5MTHF). Their presence reduces the capacity of the One Carbon cycle, and so the regeneration of Homocysteine (Hcy) and in fine strongly perturbs all the methylation processes. As methylation processes are major regulators in gametogenesis and embryogenesis. We have determined the prevalence of the 2 most important SNPs A1298C and C677T in our population of patients consulting for infertility.

METHODS

Determination of the MTHFR SNPs A1298C and C677T, by hybridization using the LAMP Human MTHFR mutation KITs.

RESULTS

Only 15.8% of our patients (861) do not carry any SNP (WT wid type). Close to 20% of the patients are homozygotes for one mutation or the other. A total of 19.7% are composite heterozygous. A total of 43% of our population is considered "at risk", based on observations collected for the repeat miscarriages.

CONCLUSIONS

Determination of the 2 major MTHFR SNPs is not a "first row" choice, but it must not be neglected and should be carried out in case of repeat ART failures and repeat miscarriages. Some simple therapeutic options can be proposed: they are based on the use of 5MTHF (5MethyleneTetraHydroFolate) the compound downstream the MTHFR.

[Social policy changes and the health of asylum seekers: 3 years after the introduction of the Asylum Law]

In the canton de Vaud, General Practioners (GPs) caring for asylum seekers under the "aide d'urgence" regime can ask for an adaptation of their housing conditions, by filling out a specific form and addressing it to the medical commission responsible for advising the EVAM (the housing institution for asylum seekers) on these issues. The forms addressed to the commission are indicative of a worrisome state of health in this population, especially for mental health. More than 70% report at least one psychiatric diagnosis. Most frequent are anxiety and depressive disorders, as well as many posttraumatic stress disorders, associated with traumatic events both in the country of origin and in Switzerland. Adapting the housing conditions, based on vulnerabilities that the GP has specifically documented, may contribute to improve the health of the most vulnerable asylum seekers.

[Facial nerve monitoring in the parotidectomy]

INTRODUCTION

Facial palsy (FP) is a feared complication of parotidectomy. Facial nerve monitoring (FNM) has been poorly evaluated since it was created at the beginning of the 90's. The authors described a retrospective series and discussed it reviewing the literature data.

SUBJECTS AND METHOD

From January 2002 to January 2009, 75 parotidectomies were performed in 72 patients (34 males, 38 females), without FNM in 28 cases (group 1) and with FNM in 47 cases (group 2).

RESULTS

In group 1, 9 FP were noted, 5 were transient and 4 were definitive. In group 2, 12 FP were noted, 9 were transient and 3 were definitive. Both one month and six months after parotidectomy, the FP rate was significatively higher in group 1 than in group 2 for the reoperations.

CONCLUSIONS

Facial nerve monitoring is an adjunctive method available to a surgeon during parotid surgery to assist with the functional preservation of the facial nerve. It did not allow to improve the facial prognosis in benign tumours removal but it improved the facial prognosis in reoperations. Its interest should be tested for malignant tumour removal.

The pedicle superficial temporalis fascial flap in oncologic reconstructive surgery of the oral cavity: how we do it and its functional results

OBJECTIVE

The authors described how they perform a pedicle superficial temporalis fascial flap in oncologic reconstructive surgery of the oral cavity and evaluated its functional results.

STUDY DESIGN

A prospective study was performed in an university hospital from September 2001 to July 2007.

SUBJECTS AND METHODS

Nine male patients underwent a pedicle superficial temporalis fascial flap to repair a soft tissue loss in the oral cavity following a tumour extraction (seven cases) or to repair osteoradionecrosis (two cases).

RESULTS

Twelve months after the intervention, a correct functional state was restored in seven out of nine cases and the anatomical congruence was correct in eight out of nine cases.

CONCLUSION

The pedicle superficial temporalis fascial flap can be useful in the reconstruction of the oral cavity, especially for patients who underwent radiotherapy. This flap was shown to be reliable, with acceptable post-operative complications, though it requires surgical experience. It is of interest for posterior and/or superior oral cavity reconstruction because the flap length, which is considerably reduced by its arc of rotation and by its path near the zygomatic process, does not allow for reconstruction of the anterior floor of the mouth. Because this flap is thin, only moderate soft tissue loss can be repaired.

Brain oxytocin receptors mediate ejaculation elicited by 7-hydroxy-2-(di-N-propylamino) tetralin (7-OH-DPAT) in anaesthetized rats

BACKGROUND AND PURPOSE

The involvement of the neuropeptide oxytocin in the control of male sexual responses is documented although its exact mechanisms of action, and especially the site(s) of action, are not fully delineated. In order to clarify this issue, we tested the effects of a peptide oxytocin antagonist delivered through different routes on sexual responses elicited, in anaesthetized male rats, by i.c.v. 7-hydroxy-2-(di-N-propylamino) tetralin (7-OH-DPAT), a dopamine agonist, preferentially active on D3 receptors.

EXPERIMENTAL APPROACH

Seminal vesicle pressure (SVP) and bulbospongiosus muscle (BS) electromyograms were recorded as physiological markers of emission and expulsion phases of ejaculation respectively and intracavernosal pressure (ICP) was monitored as a physiological marker of erection.

KEY RESULTS

When injected i.v., the oxytocin antagonist did not impair 7-OH-DPAT-induced SVP and ICP responses while BS burst frequency was diminished. When delivered i.c.v., the oxytocin antagonist dose-dependently inhibited occurrence of 7-OH-DPAT-induced sexual responses. When delivered intrathecally (i.t.) at the level of the 6th lumbar (L6) segment, but not the 13th thoracic (T13) segment, the oxytocin antagonist reduced the duration of BS responses and the occurrence of ejaculation without impairing ICP responses.

CONCLUSIONS AND IMPLICATIONS

Brain oxytocin receptors mediate male sexual responses elicited by i.c.v. 7-OH-DPAT in anaesthetized rats whereas L6 spinal oxytocin receptors only impair the occurrence of ejaculation. Peripheral oxytocin receptors are marginally involved in 7-OH-DPAT-induced sexual responses. These findings should be considered for the development of potential pharmacological treatment of premature ejaculation in man.

Effets de la stimulation sur la qualité ovocytaire

In all IVF programs, ovarian stimulation may lead to a hyperstimulation syndrome. Mild ovarian stimulations are suggested to reduce this complication of infertility treatment. In this article, we wonder what the consequences of different stimulations are on oocytes quality. The quality of the oocyte being the major factor of the development of a good embryo, it can be evaluated by direct or indirect techniques. Some are subjective. Several studies seem to show that ovarian stimulation has an influence on oocye quality, especially at a chromosomic and perharps, epigenetic level. It seems that a mild stimulation (for example with GnRH antagonist) selects less oocytes but with a better quality and produces euploid embryos. The uterine transfer of this kind of embryo should lead to an ongoing pregnancy.

Antioxidants to reduce sperm DNA fragmentation: an unexpected adverse effect

Reactive oxygen species (ROS) have a negative impact on sperm DNA, leading to the formation of oxidative products such as 8-oxo-7,8-dihydroxyguanosine. This compound causes fragmentation and, thus, has a mutagenic effect. Patient treatment with oral antioxidant vitamins is, therefore, standard practice for male infertility, in an attempt to decrease formation of ROS and improve fertility. In this study, the DNA fragmentation index and the degree of sperm decondensation were measured using the sperm chromatin structure assay before and after 90 days treatment with antioxidant vitamins associated with zinc and selenium. Antioxidant treatment led to a decrease in sperm DNA fragmentation (-19.1%, P < 0.0004), suggesting that at least part of the decay was linked to ROS. However, it also led to an unexpected negative effect: an increase in sperm decondensation with the same order of magnitude (+22.8%, P < 0.0009). The opening of interchain disulphide bridges in protamines may explain this aspect, as antioxidant vitamins, especially vitamin C, are able to open the cystin net, thus interfering with paternal gene activity during preimplantation development. This observation might explain the discrepancy observed concerning the role of these antioxidant treatments in improving male fertility.

Ejaculation induced by i.c.v. injection of the preferential dopamine D3 receptor agonist 7-hydroxy-2-(di-N-propylamino)tetralin in anesthetized rats

In addition to serotonin, dopamine within the CNS is known to play a primary role in the control of ejaculation. However, whether D(2) and/or D(3) dopamine receptor subtypes mediate this effect is still unclear. In order to clarify this issue, a pharmacological competitive study using the preferential D(3) agonist 7-hydroxy-2-(di-N-propylamino)tetralin (7-OH-DPAT) alone or in combination with competitive nonpreferential or preferential D(2) and D(3) antagonists delivered intracerebroventricularly (i.c.v.) was undertaken in anesthetized rats. Urethane-anesthetized male rats were implanted into the cerebral ventricle with a cannula for i.c.v. injections, and recording electrodes were placed within the bulbospongiosus (BS) muscle to monitor BS muscle contractions, which were used as a marker for the expulsion phase of ejaculation. Following i.c.v. injection, 7-OH-DPAT induced ejaculation and rhythmic BS muscle contractions. Co-injected i.c.v. with 7-OH-DPAT, the nonselective D(2)/D(3) antagonist (raclopride), and the preferential D(3) antagonist (S(-)-N[n-butyl-2-pyrrolidinyl)methyl]-1-methoxy-4-cyanonaphtalene-2-carboxamide; nafadotride) but not the preferential D(2) antagonist ((+/-)-3-[4-(4-chlorophenyl)-4-hydroxypiperidinyl]methylindole; L 741,626) inhibited the occurrence of ejaculation and BS muscle contractions. These results suggest that i.c.v. delivery of 7-OH-DPAT does represent a pertinent model to investigate the physio-pharmacology of ejaculation. It is inferred that targeting brain D(3) receptors may provide a therapeutic approach for treating ejaculatory disorders in humans.

Effect of acute dapoxetine administration on the pudendal motoneuron reflex in anesthetized rats: comparison with paroxetine

PURPOSE

Pudendal motoneuron reflex discharges elicited by bilateral electrical stimulation of the dorsal nerves of the penis were used as an experimental model of the expulsion reflex of ejaculation to investigate the effect of acute intravenous delivery of dapoxetine, a short acting selective serotonin reuptake inhibitor, in anesthetized rats. Dapoxetine was compared with paroxetine, the selective serotonin reuptake inhibitor of reference.

MATERIALS AND METHODS

Stimulating electrodes were placed bilaterally on the dorsal nerves of the penis and a recording electrode was placed on the motor branch of the pudendal nerve to monitor pudendal motoneuron reflex discharges in urethane anesthetized rats. Pudendal motoneuron reflex discharges induced by penile dorsal nerve stimulation were measured before and 60 minutes after a single intravenous injection of dapoxetine or paroxetine, each tested at 3 doses (1, 3 and 10 mg/kg) or after a single injection of vehicle.

RESULTS

At all doses tested dapoxetine significantly lengthened the latency of pudendal motoneuron reflex discharges following bilateral stimulation of the dorsal nerves of the penis in comparison with vehicle, whereas only the 1 mg/kg dose of paroxetine was effective. The amplitudes of pudendal motoneuron reflex discharges were significantly decreased only in rats treated with 3 mg/kg dapoxetine compared to vehicle.

CONCLUSIONS

Acute systemic delivery of selective serotonin reuptake inhibitors is capable of modulating the expulsion reflex of ejaculation in anesthetized rats with dapoxetine appearing to be more effective than paroxetine. These findings support the beneficial effect of on-demand administration of dapoxetine for premature ejaculation.

[Positron emission tomography in head and neck squamous cell carcinomas]

18F-Fluorodeoxyglucose positron emission tomography (PET) is an imaging modality which is becoming increasingly esential in oncology, especially in the management of head and neck squamous cell carcinomas (SCC). The most common uses of the PET are listed in this thematic study: initial staging, cervical lymph node metastases from an unknown primary tumor and post-therapeutic follow-up. The advantages and drawbacks of this imaging tool are exposed here according to both our experience and data from the literature. Decision schemes are suggested for each use so as to optimize the use of this imaging modality in the management of these SCC. Other fields of application for the PET are mentioned, such as the in-progress evaluation of response to chemotherapy, the interest of this imaging tool in radiotherapy as well as current biochemical developments concerning new tracers.

Clinical benefit of fulvestrant in postmenopausal women with advanced breast cancer and primary or acquired resistance to aromatase inhibitors: final results of phase II Swiss Group for Clinical Cancer Research Trial (SAKK 21/00)

BACKGROUND

The aim of this study was to evaluate the efficacy and tolerability of fulvestrant, an estrogen receptor antagonist, in postmenopausal women with hormone-responsive tumors progressing after aromatase inhibitor (AI) treatment.

PATIENTS AND METHODS

This is a phase II, open, multicenter, noncomparative study. Two patient groups were prospectively considered: group A (n=70) with AI-responsive disease and group B (n=20) with AI-resistant disease. Fulvestrant 250 mg was administered as intramuscular injection every 28 (+/-3) days.

RESULTS

All patients were pretreated with AI and 84% also with tamoxifen or toremifene; 67% had bone metastases and 45% liver metastases. Fulvestrant administration was well tolerated and yielded a clinical benefit (CB; defined as objective response or stable disease [SD] for >or=24 weeks) in 28% (90% confidence interval [CI] 19% to 39%) of patients in group A and 37% (90% CI 19% to 58%) of patients in group B. Median time to progression (TTP) was 3.6 (95% CI 3.0 to 4.8) months in group A and 3.4 (95% CI 2.5 to 6.7) months in group B.

CONCLUSIONS

Overall, 30% of patients who had progressed following prior AI treatment gained CB with fulvestrant, thereby delaying indication to start chemotherapy. Prior response to an AI did not appear to be predictive for benefit with fulvestrant.

Melanotan-II: Investigation of the inducer and facilitator effects on penile erection in anaesthetized rat

The effects of melanotan-II, a non-specific agonist of melanocortin receptors, on erection and its possible sites of action were investigated in anesthetized rats. Delivered i.v. (0.1, 0.3 and 1 mg/kg) or within the paraventricular nucleus of the hypothalamus (0.1 and 1 microg), melanotan-II exerted a dose-dependent inducer activity on erection by eliciting erectile events and shortening latency of the first erectile event to occur. Erectile events were of higher amplitude in rats treated with melanotan-II i.t. (0.2 microg) delivered at the L6-S1 level than in animals treated with the vehicle i.t. delivered. Erectile responses elicited by cavernous nerve stimulation were increased after i.v. melanotan-II (1 mg/kg), thereby exerting facilitator effect on erection. In contrast, melanotan-II injected within the corpus cavernosum (1 microg) did not display any facilitator activity. To investigate the neural pathways involved in the facilitator effect of melanotan-II, we performed acute spinalization (T8 level) and differential selective nerve transections. Neither spinalization nor bilateral transection of pelvic nerves or dorsal penile nerves impaired facilitator activity of i.v. melanotan-II (1 mg/kg). Conversely, the facilitator effect of melanotan-II was abolished after acute removal of the lumbar paravertebral sympathetic chain. These results lead to the conclusion that central and peripheral melanocortin pathways are recruited by melanotan-II, depending on its route of delivery, to exert both inducer and facilitator activities on erection.

The Use of Telemetry Technology to Test the Proerectile Effect of Melanotan-II (MT-II) in Conscious Rats

OBJECTIVE

The aim of this study is to demonstrate that monitoring, by means of telemetry technology, the increases in intracavernosal pressure (ICP) in freely moving rats using melanotan-II (MT-II) as a proerectile inducer compound is a relevant experimental model to investigate the effects of pharmacological agents on erection.

METHODS

Adult rats were implanted in the corpus cavernosum with a pressure sensor which permitted telemetric monitoring of ICP in freely moving animals following MT-II (0.1, 0.3 and 1 mg/kg) or saline i.v. injections. ICP was also measured after MT-II (0.1, 0.3 or 1 mg/kg) or saline i.v. delivery in anesthetized rats.

RESULTS

In conscious rats, MT-II (1 mg/kg) significantly increased overall erectile activity compared to saline. In anesthetized rats, MT-II-induced increase in overall erectile activity was not statistically significant but displayed a similar pattern.

CONCLUSIONS

The use of telemetry technology allowed to collect quantifiable and reliable data regarding the proerectile activity of MT-II in physiological conditions. The telemetry model appears suitable for investigating the potential inducer proerectile properties of pharmacological agents.

Potential role of inducible nitric oxide synthase in the sleep–wake states occurrence in old rats

Extensive evidences now suggest that an association between inducible nitric oxide synthase and oxidative stress takes place during aging. Since the part played by inducible nitric oxide synthase in the sleep impairments associated with aging still remains unexplored, we compared its involvement in old rats (20-24 months) versus adult ones (3-5 months) using polygraphic, biochemical, voltammetric and immunohistochemical techniques. The experiments were conducted either in basal condition or after a systemic injection of selected inducible nitric oxide synthase inhibitors. We found that 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (10 mg/kg, i.p.) or aminoguanidine (400 mg/kg, i.p.) was capable to suppress rapid-eye-movement sleep and induce a delayed enhancement in slow-wave sleep in old rats. These effects did not occur in adult animals. Within the frontal cortex, the laterodorsal tegmentum and dorsal raphe nuclei, the basal inducible nitric oxide synthase activity was 85-200% higher in old rats than in adult ones. In contrast, the neuronal nitric oxide synthase activity did not vary in both groups. 2-Amino-5,6-dihydro-6-methyl-4H-1,3-thiazine administration significantly reduced inducible nitric oxide synthase activity (70-80% according to the brain areas) independently of age, but significantly decreased the cortical nitric oxide release in old rats. Finally, in frontal cortex and dorsal raphe immunohistochemical analysis showed inducible nitric oxide synthase-positive cells again only in old animals. These data support the idea that nitric oxide produced by inducible nitric oxide synthase plays a role in the triggering and maintenance of rapid-eye-movement sleep during aging.

Recombinant human LH supplementation during GnRH antagonist administration in IVF/ICSI cycles: a prospective randomized study

BACKGROUND

When administered in the late follicular phase to prevent an LH surge, GnRH antagonists induce a sharp decrease in serum LH levels that may be detrimental for assisted reproductive technology cycle outcome. Therefore, a prospective study was designed to assess the effects of recombinant human (r)LH supplementation during GnRH antagonist (cetrorelix) administration.

METHODS

The protocol consisted of cycle programming with oral contraceptive pill, ovarian stimulation with rFSH and flexible administration of a single dose of cetrorelix (3 mg). A total of 218 patients from three IVF centres were randomized (by sealed envelopes or according to woman's birth date) to receive (n = 114) or not (n = 104) a daily injection of rLH 75 IU from GnRH antagonist initiation to hCG injection.

RESULTS

The only significant difference was a higher serum peak E2 level in patients treated with rLH (1476 +/- 787 versus 1012 +/- 659 pg/ml, P < 0.001) whereas the numbers of oocytes and embryos as well as the delivery rate (25.2 versus 24%) and the implantation rate per embryo (19.1 versus 17.4%) were similar in both groups.

CONCLUSIONS

These results show that in an unselected group of patients, there is no evident benefit to supplement GnRH antagonist-treated cycles with rLH.

Changes in the sleep-wake cycle architecture and cortical nitric oxide release during ageing in the rat

Changes in sleep-wake states and nitric oxide release were examined in aged rats versus young-adult ones. Sleep-wake recordings and nitric oxide measurements were taken from animals chronically equipped with polygraphic and voltametric electrodes. Animals were examined in baseline conditions and in response to a 24-hour paradoxical sleep deprivation. In aged rats, basal amount of paradoxical sleep is decreased during the light phase versus young-adult animals. After paradoxical sleep deprivation, a paradoxical sleep rebound occurs with an amount and intensity that are less marked in aged animals than in young-adult rats. The amplitude of the circadian distribution for wakefulness, slow-wave sleep and paradoxical sleep amounts is reduced with age. Finally, delta-slow-wave sleep and theta-paradoxical sleep power spectra are attenuated either in baseline conditions or after paradoxical sleep deprivation in aged animals. It is also reported that cortical nitric oxide release exhibits a circadian rhythm with higher amplitude in aged rats than in young-adult ones. However, after paradoxical sleep deprivation, a limited overproduction of nitric oxide is obtained compared with young-adult ones. These results, evidencing the dynamics of the nitric oxide changes occurring in relation to the sleep-wake cycle, point out the homeostatic paradoxical sleep regulation as an age-dependent process in which the nitric oxide molecule is possibly involved.

In vitro release of caffeine from concentrated W/O emulsions: effect of formulation parameters

Concentrated water in oil emulsions have been obtained with four different emulsifiers to study the effect of formulation parameters on the in vitro release of caffeine. The in vitro release was studied on polysulfone membranes. Among the four emulsifiers, only one gave a statistically higher release of caffeine after 15 h (at a fixed percentage of dispersed phase). The concentration of the emulsifier does not have a significant effect on the release of caffeine. In contrast, diffusion of caffeine from concentrated W/O emulsions has been found to be highly dependent on the internal phase volume. The flux of caffeine increases with the percentage internal water phase. The droplet diameter decreases and the apparent viscosity increases with the percentage of the dispersed phase. And, the shape of the droplets goes from spherical to polyhedral as the percentage dispersed phase is increased. However, the flux could be correlated neither with the apparent viscosity nor with the droplet diameter at a fixed percentage of the dispersed phase. Results suggest that the shape factor may have an influence on the release of caffeine from concentrated emulsions. All the release profiles followed a zero-order kinetic.

Influence of three synthetic membranes on the release of caffeine from concentrated W/O emulsions

We measured the release rate characteristics of caffeine from concentrated emulsions using three different sources of synthetic membranes. The formulations tested included, on the one hand, two stable cosmetic concentrated W/O emulsions (90% w/w) - one with a non ionic surfactant and one with a silicone surfactant - and on the other hand, a commercially available hydroalcoholic gel. All formulations contained 5% caffeine. In vitro diffusion measurements (24 h) were performed with static diffusion Franz cells. A silicone membrane could not allow us to differentiate the two concentrated emulsions (CE), but the two other membranes, not rate limiting, showed difference in the release profile of caffeine from the two CE. Results with the cellulose and polysulfone membrane showed that in vitro release of caffeine is influenced by the nature of the emulsifier in the concentrated emulsion, the non ionic surfactant being more efficient than the silicone surfactant. The polysulfone membrane was the only one that allows statistical differentiation of the three products. For further studies the polysulfone membrane will be use to make screening on concentrated emulsions.

Deletions of mob and tra pJP4 transfer functions after mating of Ralstonia eutropha JMP134 (pJP4) with Escherichia coli harboring F'::Tn10

One-tenth of Escherichia coli transconjugants resulting from the transfer of the catabolic plasmid pJP4 from Ralstonia eutropha JMP134 to E. coli XL1Blue, contained pJP4 derivatives with deletions (approximately 15-30 kb). The occurrence of these deletions is probably associated with the presence of Tn10 in the recipient. DNA endonuclease restriction analysis of the pJP4 deletion derivatives showed the absence of SphI and EcoRI fragments previously reported to hybridize with IncP Tra DNA probes. Moreover, these pJP4 deletion derivatives are not able to self-transfer, nor are they able to be mobilized. Accordingly, these pJP4 deletion derivatives lack transfer functions.

Degradation of trichlorophenols by Alcaligenes eutrophus JMP134

The degradation of chlorophenols by Alcaligenes eutrophus JMP134 (pJP4) was studied. The strain grew on 2,4,6-trichlorophenol or 2,4,6-tribromophenol as the sole carbon and energy source. Complete degradation of 2,4,6-trichlorophenol was confirmed by chloride release and gas chromatography analysis of supernatants from growth cultures. The 2,3,5-, 2,3,4-, 2,3,6- and 2,4,5-isomers of trichlorophenol did not support growth. However, up to 40% of 2,4,5-trichlorophenol was mineralized during growth of A. eutrophus on chemostats fed with either phenol (0.4 mM) or 2,4,6-trichlorophenol (0.4 mM) plus 2,4,5-trichlorophenol (0.1 mM). Growth on 2,4,6-trihalophenols was also observed in A. eutrophus JMP222, the strain lacking pJP4, suggesting that this new degradative ability reported for A. eutrophus is not related to pJP4 encoded catabolic functions.

[Thoracic epidural anesthesia for extracorporeal lithotripsy. Comparison of 4 anesthetic solutions]

Extracorporeal shock-wave lithotripsy (ESWL) is a new non-invasive procedure allowing disintegration of upper urinary tract calculi, usually carried out in epidural anaesthesia (EA). The patient strapped to a stretcher is immersed in a bath. At the bottom of the tube is the shock-wave generator. The release of shock waves (1,000 to 2,000 for each treatment) is triggered by the R-wave of the patient's ECG. Arrhythmias and extrasystoles (ES) may occur. In the investigational trial, the preferred anaesthesia was continuous lumbar EA with a large volume of 2% lidocaine extended to the level of T6. This study was conducted to assess continuous thoracic EA at the T12 interspace with a lesser dose (12 ml) of 2% lidocaine (XT, comparing it with single dose EA with the same volume of three other agents: bupivacaine 0.5% (Ma) and mixtures of 2% lidocaine-0.2+ tetracaine (XT), and 2% lidocaine-fentanyl 50 micrograms (XF), all with 1/200,000th adrenaline. Eighty patients (ASA class I or II) were assigned randomly to receive one of the four types of EA. All were monitored with Holter's method. The demographic distribution was similar for the four groups. Mean duration of the procedure was 32 +/- 15 min. Premedication was given only in 16 patients, very anxious. The results were excellent in 68 patients; 11 had to be supplemented with one or two doses of intravenous agents: diazepam and/or fentanyl: one failure was given an intravenous general anaesthesia. Mild hypotension occurred in four patients. 242 ES occurred in 48 patients (60%).(ABSTRACT TRUNCATED AT 250 WORDS)

The use of a mathematical model in rhinomanometry

The authors consider the mathematical model proposed by the Swedish Group (Broms et al.). This model permits the pressure gradient-flow recording as obtained from anterior or posterior rhinomanometry to be converted into a mathematical formula. The model was tested for its mathematical, statistical, and clinical utility with 32 normal test subjects. It is the conviction of the authors, although not totally without reservation, that this is the best mathematical model in existence.

Correlations between ultrastructural features and contraction rates in rotiferan muscle. I. Preliminary observations on longitudinal retractor muscles in Trichocerca rattus

The Rotifer Trichocerca rattus has striated longitudinal retractor muscles. These muscles can be divided into two categories: 1. The central and ventral retractor muscles which, after fixation, are found in a supercontracted state: they probably contract very quickly. 2. The lateral retractor muscles which are in a relaxed state after fixation. However, if the animal is mechanically stimulated before fixation, these are also fixed in a contracted state: so, normally, these muscles probably contract more slowly than the first category. In the relaxed state, thin myofilaments of the lateral retractor muscles are folded at the I band level; this a consequence of their compression provoked by the contraction of central and ventral retractor muscles. In muscles of the first type, the thick myofilaments are shorter (less than 2 mu) than in the second type (2.5 mu).

SELF-INDUCED TELEVISION EPILEPSY. A study of 2 patients

A unique method of deliberate self-induction of epileptic seizures, using the TV screen was encountered in two young women. Both suffered from highly photosensitive primary generalized corticoreticular orcentrencephalic epilepsy. Self-precipitation developed in periods of their life when spontaneous attacks no longer occurred. The seizures consisted of absence or generalized tonic clonic attacks. (The latter are almost never encountered in "hand waving", the most common form of self-induction reported in the literature.) The seizures were almost always induced in situations of guilt and/or frustation. They were followed by a feeling of tension relief rather than pleasure. Both patients were reluctant to discuss the circumstances under which self-induction occurred, and had difficulty in accepting psychotherapy or complying with antiepileptic medication. The similarity between the two young women was striking, and suggests that patients with this and other forms of self-induced epilepsy should be more fully studied from a psychiatric point of view.