Glutamine: recent developments in research on the clinical significance of glutamine

PURPOSE OF REVIEW: The aim of this review is to describe the clinical relevance of supplementation of glutamine from the recent literature. First, new basic research is examined and subsequently recent clinical trials and a metaanalysis are illustrated. RECENT FINDINGS: Glutamine has a major impact on the functionality of the immune system. It has recently been established that glutamine not only has a protective effect on cells of the immune system, but also on other cells of the body, for instance cardiomyocytes. Evidence is accumulating for an effect of glutamine via glutathione, heat shock proteins as well as taurine. Another area of interest is the way glutamine enhances gut barrier function. More and more research is concentrating on the positive effect of glutamine on the gut-associated lymphoid tissue. SUMMARY: Based on a recent meta-analysis and up-to-date clinical trials, we may conclude that glutamine has a beneficial effect on infectious complications and reduces hospital stay. In critically ill patients glutamine supplementation may reduce morbidity and mortality. The greatest effect was observed in patients receiving high dose parenteral glutamine. A recent study with high dose enteral glutamine demonstrated a reduced mortality in the glutamine supplemented group. In the future more trials with larger numbers of participants are needed, especially with high dose enteral glutamine in the perioperatively and the intensive care unit setting.     

Short-term variations in bone remodeling markers of an oral contraception formulation containing 3 mg of drospirenone plus 30 microg of ethinyl estradiol: observational study in young postadolescent women

The clinical study of treated subjects and nontreated controls was made in healthy eumenorrheic young postadolescent women volunteers in the Department of Obstetrics and Gynaecology at Cagliari University, to investigate whether an oral contraceptive (OC) containing drospirenone (3 mg) plus ethinyl estradiol (30 microg) (DRSP+EE) can affect bone metabolism. Control group (n = 26) and OC group (n = 28) women did not differ in age, body mass index, waist-to-hip ratio and main outcome measures [urinary levels of deoxypyridinoline and pyridinoline, serum levels of osteocalcin, bone specific alkaline phosphatase (bSAP), total testosterone (total-T), sex hormone-binding globulin (SHBG), progesterone and bone mineral density (BMD) at the heel]. The control group was studied at the luteal phase (LP) during both the first and the sixth menstrual cycle; the OC group was studied during the first cycle at the LP, and on days 16-18 of the sixth cycle of DRSP+EE treatment. At the sixth cycle, in the control group, the main outcome measures did not change compared to baseline. In the OC group, deoxypyridinoline, pyridinoline, osteocalcin, bSAP, total-T and progesterone levels were reduced, whereas SHBG levels were increased. The BMD was unchanged compared to baseline. The results suggest that 6-month DRSP+EE treatment decreases bone turnover.     

Bilateral laparoscopic transperitoneal ligation of ovarian veins for treatment of pelvic congestion syndrome

STUDY OBJECTIVE: To evaluate the efficacy and safety of bilateral laparoscopic transperitoneal ligation of the ovarian veins in women with symptomatic pelvic varices. DESIGN: Prospective pilot study performed in a small series (Canadian Task Force classification III). SETTING: Urban hospital in Turin and University hospital in Cagliari, Italy. PATIENTS: Twenty-three women. INTERVENTION: Bilateral laparoscopic transperitoneal ligation of the ovarian veins. The right ovarian vein was reached by incising posterior peritoneum below the mesentericoparietal fossa in all women. The left ovarian vein was reached by reflecting medially the left colon in 10 women and by incising the posterior peritoneum covering the aorta 2 cm below the inferior duodenal fold in 13. MEASUREMENTS AND MAIN RESULTS: After the plateau of the learning curve was reached, average operating time was about 60 minutes without complications. Complete remission of pain and absence of pelvic varicosities lasted for 12 months. CONCLUSION: The laparoscopic transperitoneal paraaortic approach to bilateral ligation of ovarian veins near their origin could be a new treatment option for pelvic congestion syndrome.     

Central oxytocinergic neurotransmission: a drug target for the therapy of psychogenic erectile dysfunction

A group of oxytocinergic neurons originating in the paraventricular nucleus of the hypothalamus and projecting to extrahypothalamic brain areas (e.g. hippocampus, medulla oblongata and spinal cord) control penile erection. Activation of these neurons by dopamine and dopamine agonists, excitatory amino acids (N-methyl-D-aspartic acid) or oxytocin itself, or by electrical stimulation leads to penile erection, while their inhibition by GABA and GABA agonists or by opioid peptides and opiate-like drugs inhibits this sexual response. The activation of oxytocinergic neurons in the paraventricular nucleus by dopamine, oxytocin and excitatory amino acids is apparently secondary to the activation of nitric oxide (NO) synthase. NO in turn activates, by a mechanism that is as yet unidentified, the release of oxytocin from oxytocinergic neurons in extrahypothalamic brain areas. Several peptide analogues of hexarelin, a growth hormone releasing peptide, also induce penile erection when injected into the paraventricular nucleus and, to a lesser extent, systemically, apparently by acting on a specific receptor to activate oxytocinergic neurons as shown for the above drugs and oxytocin. Paraventricular oxytocinergic neurons and mechanisms similar to those reported above are also involved in the expression of penile erection in physiological contexts, namely when penile erection is induced in the male by the presence of an inaccessible receptive female, which is considered a model for psychogenic impotence in man, as well as during copulation. These findings show that paraventricular oxytocinergic neurons projecting to extra-hypothalamic brain areas and to the spinal cord are a likely target for the treatment of erectile dysfunction of central origin.     

Screening of nutritional status in The Netherlands

BACKGROUND AND AIMS: In 2001, the Dutch Dietetic Association conducted a national screening on malnutrition. The goal of this screening was to determine the prevalence of disease-related malnutrition in The Netherlands in all fields of medical care and to investigate the involvement of the dietitian in the treatment of malnutrition. METHODS: Eight thousand five hundred and twenty nine patients were screened of which data of 7606 patients could be analysed. Eighty one per cent (6150) of the patients were hospital patients. Eleven per cent (808) of the patients lived in a nursing home. Seven per cent (533) of the patients were home-care patients, who were measured at home or at the general practitioner's office. The origin of 115 patients (2%) was not registered. Age, height, weight, unintentional weight loss, kind of illness and intervention by a dietitian were registered. Malnutrition was defined as >10% unintentional weight loss during the past 6 months and risk of malnutrition was defined as 5-10% unintentional weight loss during the past 6 months. RESULTS: Twelve per cent (884) of all patients appeared to be malnourished. Thirteen per cent (962) were at risk of malnutrition and 75% (5760) were well nourished. Fifty four per cent of the malnourished patients were referred to a dietitian.Oncological disease was more associated with malnutrition than non-oncological disease (in particular in the head and neck, lung and intestinal areas). Also, non-oncological gastro-intestinal and lung disease patients were often categorised as malnourished. Elderly patients (>75 years) were more at risk of malnutrition. BMI and unintentional weight loss did not correlate well. CONCLUSION: In this national survey conducted by dietitians, including a convenience sample of mainly institutionalised patients, approximately 25% of patients in all medical fields were categorised as moderately or severely malnourished. About half of these patients were seen by a dietitian.     

<Emphasis Type="Bold">Reproductive Endocrinology:</Emphasis> Uterine Perfusion and Hormonal Pattern in Patients with Polycystic Ovary Syndrome

Purpose: To evaluate whether polycystic ovary syndrome (PCOS) patients with different pulsatility index (PI) of uterine artery showed differences in their hormonal pattern. Methods: Eighty-eight PCOS-affected patients and 15 controls were submitted to Doppler flow measurement of uterine artery; LH, FSH PRL, estradiol, and androgens concentration determination; and BMI evaluation during early follicular phase. Results: The mean PI of uterine artery of PCOS patients was significantly higher than control group (2.97 ± 0.9 vs. 1.89 ± 0.2 respectively). The distribution of the PI'values was significantly different in the PCOS-affected patients and in control group. The plasma levels of DHEAS and BMI were significantly higher in PCOS patients with PI 3 than in PCOS patients with PI < 3. Conclusion: High resistance in the uterine artery is present in PCOS patients, but a wide range PI values of uterine artery is present. BMI and DHEAS seem to be factors interfering with uterine perfusion.     

Differences in autonomic physiological responses between good and poor inductive reasoners

We investigated individual- and task-related differences in autonomic physiological responses induced by time limited figural and verbal inductive reasoning tasks. In a group of 52 participants, the percentage of correctly responded task items was evaluated together with nine different autonomic physiological response measures and respiration rate (RR). Weighted multidimensional scaling analyses of the physiological responses revealed three underlying dimensions, primarily characterized by RR, parasympathetic, and sympathetic activity. RR and sympathetic activity appeared to be relatively more important response dimensions for poor reasoners, whereas parasympathetic responsivity was relatively more important for good reasoners. These results suggest that poor reasoners showed higher levels of cognitive processing intensity than good reasoners. Furthermore, for the good reasoners, the dimension of sympathetic activity was relatively more important during the figural than during the verbal reasoning task, which was explained in terms of hemispheric lateralization in autonomic function.     

The vestibulospinal reflex in humans: effects on paraspinal muscle activity

OBJECTIVE: To elucidate the electromyographic (EMG) patterns elicited in the superficial paraspinal muscles (sacrospinalis, ileocostalis lomborum, longissimus dorsi and splenium cervicis). MATERIAL AND METHODS: In normal subjects adapted to the dark and standing on a force platform, EMG patterns were elicited in the superficial paraspinal muscles by means of unilateral cold caloric stimulation of the labyrinth. RESULTS: Almost concomitantly with the occurrence of postural derangement of the subject's trunk and head, the EMG patterns of the paraspinal muscles on both sides showed significant and consistent changes. In particular, the paraspinal muscles ipsilateral to the stimulated side showed a significant reduction in activity, while the homologous muscles of the contralateral side markedly increased their activity, with a consistent delay in comparison to the contralateral muscles. Moreover, the EMG changes occurred in a hierarchic fashion in the caudal-rostral direction. In fact, the more powerful and longer-lasting effects were consistently observed in the more caudal muscles, i.e. the sacrospinalis and ileocostalis, while the effects on the longissimus dorsi and splenium cervicis muscles were weak and inconsistent. CONCLUSION: These results suggest a possible use for the EMG patterns resulting from unilateral cold caloric stimulation for clinical evaluation of the vestibulospinal reflex.     

EP 91073 prevents EP 80661-induced penile erection: new evidence for the existence of specific EP peptide receptors mediating penile erection

The effect of EP 91073, EP 51389, EP 70555 and EP 51216, peptide analogues of the growth hormone releasing peptide hexarelin, on penile erection induced by EP 80661 or EP 60761 injected into the paraventricular nucleus of the hypothalamus, was studied in male rats. Of the above peptides only EP 91073 (0.2-1 microg) was found capable of reducing penile erection induced by EP 80661 or EP 60761, when given into the paraventricular nucleus. Despite its ability to prevent EP peptide-induced penile erection, EP 91073 (1 microg) was unable to prevent penile erection induced by the dopamine receptor agonist apomorphine (50 ng), oxytocin (30 ng) and N-methyl-D-aspartic acid (50 ng), when given into the paraventricular nucleus 10 min prior to the above substances. The EP 91073-induced prevention of penile erection occurred with a reduction in the increase in nitric oxide production that occurs in the paraventricular nucleus concomitant to penile erection induced by EP 80661 and EP 60761, as measured by intracerebral vertical microdialysis. The present results are in line with the hypothesis that EP 80661 and EP 60761 induce penile erection by activating specific receptors in the paraventricular nucleus, located possibly in oxytocinergic neurons mediating penile erection, and show that EP 91073 acts as an antagonist of these EP peptide receptors mediating penile erection.