Melatonin in sleep disorders

Melatonin is the main hormone involved in the control of the sleep-wake cycle. It is easily synthesisable and can be administered orally, which has led to interest in its use as a treatment for insomnia. Moreover, as production of the hormone decreases with age, in inverse correlation with the frequency of poor sleep quality, it has been suggested that melatonin deficit is at least partly responsible for sleep disorders. Treating this age-related deficit would therefore appear to be a natural way of restoring sleep quality, which is lost as patients age. However, despite the undeniable theoretical appeal of this approach to insomnia, little scientific evidence is available that supports any benefit of this substitutive therapy. Furthermore, the most suitable dose ranges and pharmaceutical preparations for melatonin administration are yet to be clearly defined. This review addresses the physiology of melatonin, the different pharmaceutical preparations, and data on its clinical usefulness.

Sleep biosignature of Type 2 diabetes: a case-control study

AIM

To determine whether or not the sleep disturbances associated with Type 2 diabetes affect the structure of sleep.

METHODS

We designed a case-control study in 76 patients with Type 2 diabetes and 76 control subjects without Type 2 diabetes, matched by age, gender, BMI and waist and neck circumferences. A subgroup of 32 patients with Type 2 diabetes was also matched with 64 control subjects without Type 2 diabetes according to apnoea-hypopnoea index score. Examination included an overnight full polysomnography.

RESULTS

No differences in the percentage of time spent in either rapid eye movement or non-rapid eye movement sleep were observed between groups; however, patients with Type 2 diabetes had more microarousal events during sleep than control subjects [41.4 (total range 4.0-104.4) vs 20.7 (total range 1.3-94.5) events/h; P < 0.001]. These differences were mainly observed during the non-rapid eye movement sleep [7.4 (total range 0-107.2) vs 0.2 (total range 0-65.2) events/h; P < 0.001]. In addition, sleep variables related to oxygen saturation measures, such as the percentage of time spent with oxygen saturation ≤90%, were significantly greater during the rapid eye movement sleep in patients with Type 2 diabetes [20.3 (total range 0-99.2) vs. 10.5 (total range 0-94.0)%; P = 0.047]. This pattern was maintained in the subgroup of patients matched by apnoea-hypopnaea index. Finally, stepwise regression analyses showed that apnoea-hypopnoea index, the presence of Type 2 diabetes and fasting plasma glucose value were independently associated with the number of microarousals (R² =0.667).

CONCLUSIONS

Type 2 diabetes is associated with an altered sleep structure, with different effects according to rapid eye movement (increase in nocturnal hypoxia) or non-rapid eye movement (increase in sleep fragmentation) sleep.

Fabrication of heterogeneous biocatalyst tethering artificial prosthetic groups to obtain omega-3-fatty acids by selective hydrolysis of fish oils

Immobilized enzymes tethering artificial prosthetic groups improve both the hydrolysis rate and the selectivity towards the eicosapentaenoic acid acyl chains.

Synthesis of a heterogeneous artificial metallolipase with chimeric catalytic activity

The practical synthesis in high overall yields of a heterogeneous artificial copper-lipase with chimeric catalytic activity (native plus artificial) is presented here. This novel hybrid catalyst showed excellent catalytic properties in Diels–Alder and cascade reactions.

Un nuevo caso de Blastomicoma Blastomicoide Sudamericano

Desde 1937, año en que P. WEISS y T. ZAVALETA publicaron el primer caso peruano de la micosis profunda denominado Blastomicosis Sudamericana, esta afección ha sido objeto de estudio entre nosotros habiéndose referido hasta ahora 20 casos publicados y 10 en curso de estudio y motivo de Tesis (O.R.), todos procedentes de nuestra amazonía.

[Treating acute postoperative pain: evaluation of results on the surgical ward]

OBJECTIVE

To describe management of acute postoperative pain on the surgical ward. To study the relationship between pain and a variety of surgical procedures and approaches. To determine the level of information patients received, their expectations, and their satisfaction with treatment of postoperative pain.

PATIENTS AND METHODS

Cross-sectional observational study by survey and review of patient records. We studied 234 patients, including all who were hospitalized for more than 24 hours after scheduled or emergency operations. The main variables recorded were pain intensity at rest and during movement, including on the day after surgery, and the surgical procedure and approach.

RESULTS

The prevalence of pain (>3 on a numerical scale) on the surgical ward was 33% at rest and 66% during movement. The prevalence of intense pain (>6 on the numerical scale) was 1.7% at rest and 7.3% during movement. Factors related to greater pain intensity were timing, that is, the first day after surgery, when 74.4% of patients experienced their most intense pain; type of surgery and approach (P<.004); and expecting to experience moderate or intense pain (P<.001).

CONCLUSIONS

Recording the prevalence of postoperative pain on a surgical ward provides information about the real situation of acute postoperative pain control. Pain on movement is a principal indicator for detecting groups of patients for whom analgesic protocols could be improved. Type of surgery and approach is a fundamental factor to consider when comparing the results of analgesic protocols.

Strokes and their relationship with sleep and sleep disorders

INTRODUCTION

In the current population, strokes are one of the most important causes of morbidity and mortality, to which new risk factors are increasingly being attributed. Of late, there is increased interest in the relationship between sleep disorders and strokes as regards risk and prognosis.

DEVELOPMENT

This article presents the changes in sleep architecture and brain activity in stroke patients, as well as the interaction between stroke and sleep disorders, including those which may also influence the outcome and recovery from strokes. The different treatments discussed in the literature are also reviewed, as correct treatment of such sleep disorders may not only improve quality of life and reduce after-effects, but can also increase life expectancy.

CONCLUSIONS

Sleep disorders are becoming increasingly associated with stroke. In addition to being a risk factor, they can also interfere in the outcome and recovery of stroke patients. This article aims to present an exhaustive and current review on strokes and their relationship with sleep alterations and sleep disorders.

A phase I trial of E7974 administered on days 1, 8, and 15 of a 28-day cycle in patients with solid malignancies

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Background: E7974 is a synthetic hemiasterlin analogue exhibiting binding to a and β tubulin. It induces disruption of spindle formation and mitotic arrest characteristic of anti-tubulin cancer drugs. Unlike taxanes and vincas, E7974 is a poor substrate for the PgP drug efflux pump, potentially overcoming this common mechanism of drug resistance. E7974 demonstrates broad anti-tumor activity against a number of human tumor xenografts. Methods: We conducted the initial Phase I trial using an accelerated dose escalation design to determine the maximum tolerated dose (MTD) and pharmacokinetic (PK) profile of E7974 administered IV over 2–5 minutes on Days 1, 8, and 15 of a 28-day cycle. Results: Sixteen patients (7 male, 9 female) with a variety of tumor types and a median age of 54 yrs.(range: 33–78 yrs) were treated at doses of 0.15 mg/m2, 0.21 mg/m2, and 0.29 mg/m2. In the accelerated phase, 0.15 mg/m2 and 0.21 mg/m2 were tolerated. At the 0.29 mg/m2 dose level, one patient experienced grade 4 neutropenia after Day 8. Expansion of the 0.21 mg/m2 dose level resulted in one patient experiencing grade 4 neutropenic fever. Two other patients experienced grades 2 and 3 neutropenia, resulting in delayed dosing beyond Cycle 1. Five additional patients were treated at 0.15 mg/m2; none experienced a DLT or dose delay, thus confirming 0.15 mg/m2 as the MTD. Other observed drug- related toxicities included mild to moderate fatigue, nausea, vomiting, constipation, neuropathy, and myalgias. The PK profile of E7974 can be characterized by moderate to large distribution (Vss = 50 - 133 L), slow clearance (CL = 1.4 - 9 L/hr) and moderate to slow elimination (t1/2 = 6.3 - 31 hr). Approximately 34 - 84% of the administered dose was recovered unchanged in the urine 48 hours post-dose. Stable disease was seen in one patient with colorectal cancer (6 cycles). The MTD cohort has been expanded to a total of 16 evaluable patients for confirmation of tolerability and PK. Conclusions: The recommended Phase 2 dose on Days 1, 8, and 15 of a 28-day schedule is 0.15 mg/m2. Observed toxicities were manageable and reversible. Enrollment is ongoing.

[Table: see text]

Molecular mechanisms of glutamate release by bovine chromaffin cells in primary culture

Previous work indicated that glutamate could be involved in the regulation of catecholamine secretion in bovine chromaffin cells. Thus, the question arises on the source of this putative regulatory glutamate. In this work we have examined the possibility that glutamate could be released from chromaffin cells. Data from this study indicate that chromaffin cells are able to release glutamate when they are stimulated by different depolarising agents such as 60 mM KCl, 1 mM 4-aminopyridine or 50 microM veratridine. The amount of glutamate released by these compounds was 0.32 nmol/10(6) cells (9.24% of cellular glutamate content), 0.275 (7.86%) and 0.158 (4.52%) for KCl, 4-AP and veratridine stimulation, respectively. All these catecholamine-secretagogues induced glutamate secretion by two mechanisms: 1) a Ca(2+)-dependent, probably exocytotic, mechanism and 2) a Ca(2+)-independent mechanism mediated by reversion of the electrogenic glutamate transporter. Analysis of Ca(2+)-dependent and independent releases for different compounds carried out by several experimental approaches, indicate that Ca(2+)-dependent release was the predominant mechanism for release induced by 4-aminopyridine (84% of total release) and high KCl (63%) whilst Ca(2+)-independent release was predominant for veratridine (67%). The Ca(2+)-dependent glutamate release evoked by depolarisation of chromaffin cells with high KCl and 4-AP could be split into both a fast and a slow kinetic component, which might correspond to the release of docked and mobilised chromaffin granules, respectively. On the other hand, depolarisation of cells with veratridine result in glutamate release with only the fast kinetic component. In the case of 60 mM KCl-evoked glutamate release, the fast component exhibited a decay time of <1 s and accounted for 0.63 nmol glu/6x10(6) cells (70% of total exocytotic release), whereas the slow component, which exhibited a decay time of 231 s, accounted for the release of 0.27 nmol glu/6x10(6) cells (30% of total exocytotic release). By contrast in the case of 4-aminopyridine the fast component of exocytosis only represents a 19% of total secretion and the slow a 81% with a decay time of 94 s. These data are very similar to those found in neurones and support the possible intracellular origin of glutamate having a role in the regulation of catecholamine secretion from chromaffin cells. In support of this, we have found that glutamate secretion could be evoked by stimulation of the nicotinic cholinergic receptors.

[Insomnia in the elderly: cognitive involvement and therapeutic attitudes]

INTRODUCTION

Sleep is an important biological function, which greatly affects the quality of life at all ages. Sleep influences the alertness and stress levels, psychosomatic diseases and health in general.

DEVELOPMENT

The predisposition to insomnia increases with age, illnesses such as heart disease, breathing disorders, cancer, strokes, pain and polyuria often disturb sleep patterns. In addition, the aging process, which directly alters sleep-wake cycles and other cerebral functions, affects the elderly. All the above points can lead to an increase in sleep latency, less total sleep time, increases in early awakening and a greater frequency of daytime naps. In an attempt to improve sleep in the elderly, and thus their quality of life, we can try to prevent stress and psychiatric symptoms by altering life-styles and improve the patients' awareness of the problem. Hypnotic drugs are useful for short periods but for longer ones we prefer techniques which attempt to modify behavior. In chronic patients who need treatment with hypnotic drugs for a long time, therapy must be individualized.

Prevention of asthma with ketotifen in preasthmatic children: a three-year follow-up study

Growing morbidity and mortality rates call for research towards more effective methods of preventing asthma. During the last decade several groups have reported the results of natural history and asthma prevention studies. However, the attempt to prevent development of asthma in genetically predisposed children, has not resulted in a generally accepted management scheme. The aim of this study was to evaluate the effectiveness of ketotifen in preventing the onset of asthma in infants considered to be at high risk of developing the disease, but who had no history of respiratory obstruction. These children have been described as preasthmatic. In this double-blind, placebo-controlled, parallel study, 100 infants with a family history of major allergy and elevated serum IgE levels, but with no history of bronchial obstruction, were treated with either ketotifen (n = 50) or placebo (n = 50) over a 3-year period. There were no statistically significant differences between the two groups with regard to age, sex, degree of hereditary allergy, levels of serum IgE upon joining the study, and family smoking habits. At the end of 3 years, only four of the 45 infants who had received ketotifen had developed asthma (9%). Of the 40 children given placebo, 14 had developed asthma (35%) (P = 0.003). These results suggest that ketotifen is effective in preventing the onset of asthma in preasthmatic children.

Phase advancement of slow-wave sleep in a patient with periodic hypersomnia

Twenty-four-hour polysomnographic recordings were obtained during asymptomatic (ASP) and symptomatic (SP) periods in a patient with periodic hypersomnia. During both periods, an abnormal sleep architecture was detected, with a greater sleep fragmentation during the SP. An unexpected finding was a shortening of the latency of slow-wave sleep, with a difference of more than 5 hours between the ASP and the SP. The greater fragmentation of rapid eye movement sleep during the SP may suggest a disorganization of the ultradian rhythm of rapid eye movement sleep.

Differential reactivity of Agaricus bisporus lectin with human IgA subclasses in gel precipitation

The interaction between purified Agaricus bisporus lectin and several human proteins was studied using the Ouchterlony double diffusion and immunoelectrophoresis techniques. Only one precipitation line was observed with normal human serum, normal human colostrum, IgA1 myeloma serum, both serum monoclonal and secretory IgA1 and monoclonal IgD. No reaction was observed with monoclonal and secretory IgA2, IgG, IgM, alpha 2 macroglobulin or pregnancy-associated alpha 2 glycoprotein. These results were confirmed by hemagglutination inhibition assays when IgA1, IgA2 and IgD were tested. On the basis of this reactivity, ABL could be a useful tool for distinguishing and isolating human IgA subclasses.

IgM in saliva from allergic children

In this study the authors investigated the relationship between secretory IgA levels and the appearance of a compensatory mechanism, through IgM action in allergic children.

A simple method for quantifying IgM of low molecular weight

A new and simple method for quantitation of IgM of low molecular weight in sera by radial immunodiffusion in 7% agar gel is described. The test is easy to perform and permits exact determination of low molecular weight IgM concentration down to very small quantities (1 mg%). Results obtained with the method described agree with previously used assay procedures and offer the advantage of convenience and rapidity.

Induction of organ-specific antigens of the rabbit male accessory glands by injection of testosterone or gonadotrophin

Highly specific antiserums for two antigens of rabbit male accessory glands, called FII and FV, were used to study the effect of hormonal treatment on their appearance during postnatal development. Single or double serial injection of testosterone, or human chorionic gonadotrophin, produces an increase in accessory gland and testis weight, and at the same time induces the synthesis of a detectable amount of specific antigens. This was proved by using groups of animals 4 and 6 1/2 weeks old. The antigens were consistently absent in accessory glands from normal and control animals of the same age. The histologic characteristics of maturation were also observed. Ultrastructural studies revealed an increase in number of microvilli supranuclear vaculoes with secretory content and well developed rough endoplasmic reticulum. These changes were more easily detected in young animals treated with chorionic gonadotrophin. The significance of these findings is discussed in relation to the presence of specific carriers (cytosols).