Structural elucidation of derivatives of polyfunctional metabolites after methyl chloroformate derivatization by high-resolution mass spectrometry gas chromatography. Application to microbiota metabolites

Metabolomics has become an essential discipline in the study of microbiome, emerging gas chromatography coupled to mass spectrometry as the most mature, robust, and reproducible analytical technique. Silylation is the most widely used chemical derivatization strategy, although it has some limitations. In this regard, alkylation by alkyl chloroformate offers some advantages, such as a rapid reaction, milder conditions, better reproducibility, and the generation of more stable derivatives. However, commercial spectral libraries do not include many of the alkyl derivatives, mainly for polyfunctional metabolites, which can form multiple derivatives. That introduces a huge bias in untargeted metabolomics leading to common errors such as duplicates, unknowns, misidentifications, wrong assignations, and incomplete results from which non-reliable findings and conclusions will be retrieved. For this reason, the purpose of this study is to overcome these shortcomings and to expand the knowledge of metabolites in general and especially those closely related to the gut microbiota through the thorough study of the reactivity of the different functional groups in real matrix derivatized by methyl chloroformate, a common representative alkylation reagent. To this end, a systematic workflow has been developed based on exhaustive structural elucidation, along with computational simulation, and taking advantage of the high sensitivity and high-resolution gas chromatography-mass spectrometry. Several empirical rules have been established according to chemically different entities (free fatty acids, amino acids, polyols, sugars, amines, and polyfunctional groups, etc.) to predict the number of derivatives formed from a single metabolite, as well as their elution order and structure. In this work, some methyl chloroformate derivatives not previously reported as well as the mechanisms to explain them are given. Extremely important is the interconversion of E- and Z- geometric isomers of unsaturated dicarboxylic acids (case of fumaric-maleic and case of citraconic-mesaconic acids), or the formation of cycled derivatives for amino acids, as well as common metabolites, as in the case of serine and cysteine, and many others.

Is the use of long-acting injectable antipsychotic extended in the outpatient treatment of bipolar disorder? A brief description

Aims

Obtain and analyze information on treatment guidelines, with particular emphasis on the use of antipsychotics, in patients diagnosed with bipolar disorder I and bipolar disorder II who are treated at a mental health center in a district of Madrid (Spain) under the conditions of habitual clinical practice.

Then, compare with recently published literature.

Methods

We performed a descriptive study of a sample of 100 patients diagnosed with bipolar disorder (type I and type II) at any stage of the disease who receive regular treatment in a mental health center in a district of Madrid. Information regarding the treatment used, especially the use of antipsychotics (either in a single therapy or in combination with other drugs such as mood stabilizers, antidepressants, hypnotics or anxiolytics), was collected retrospectively from the data obtained from the medical record.

Results

Ninety-four percent of patients are taking mood stabilizer treatment (68% lithium, 24% valproate, 1% and 1% carbamazepine and lamotrigine). Four percent take lithium and valproate in combination. Forty-eight percent of patients are taking some antipsychotic (atypical about 90%). Of these, only 10% in injectable form, and 5% take both oral and injectable antipsychotics.

Conclusions

The diminished use of injectable antipsychotics, well below recent publications, draws the attention. You can probably explain this low proportion of injectable medication because we are generally dealing with stable patients with a long-term disorder.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Autism, psychosis and marfan: The Lujan–Fryns syndrome

Objectives

We report the case of a 19-year-old male who was brought to our psychiatry consultation by his family for behavioural disorders and poor school performance of years of evolution.

Results

We found ourselves before a tall, thin, childish, suspicious, perplex, inhibited and minimizer patient, so we sent him to our hospital for psychiatric admission, where he showed a flowery delirium of mystic, religious and megalomaniac content; complex visual and auditory hallucinatory phenomena; and where he was diagnosed of acute polymorphic psychotic disorder and autism spectrum disorder with marfanoid habit. Therefore, we suspected a Lujan–Fryns syndrome and requested genetic confirmation. Risperidone was prescribed as solo treatment, with a rapid control of the symptoms.

Conclusions

Lujan–Fryns syndrome, first described in 1984, corresponds to a sequence mutation in exon 22 of med12 gene of chromosome X. It is hard to suspect and diagnose before puberty. Those affected have marfanoid habit and also other psychiatric manifestations such as autistic behaviour, mild-moderate mental retardation (there are some reported cases with normal intelligence), language disorders, emotional instability, aggressiveness, hyperactivity, shyness which can be extreme, obsessive-compulsive disorder, isolation, delusions, visual and auditory hallucinations, and there are cases that describe schizophrenia. Its diagnosis requires adequate physical and psychopathological examination, and it is established with clinical suspicion and genetic confirmation. There are very few cases described and there is little bibliography available about Lujan–Fryns syndrome [1].

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Dissociative Amnesia with Fugue vs. Shenjing Shuairuo: A Clinical Case Report. Are DSM-5 Distress Cultural Considerations Truly Transcultural Relevant?

Introduction

We present the case report of a 21-year-old Chinese female, who was brought to the emergency department. We open the debate between the operative criteria stablished by DSM-5 of the clinical entity dissociative amnesia and Shenjing Shuairuo - the Chinese “culture-bound syndrome”.

Objectives

To expose the relevance of the cultural formulation in the clinical evaluation of patients with a different non-Western culture in Psychiatry.

Aims

The Shenjing Shuairuo syndrome (“nervous system weakness”) was originally descripted in China, it has a gradual onset, usually after a stressful event. It involves a minimum 3 of 5 symptoms group: weakness, emotions, excitement, neurological pain and sleep. This complex group of symptoms overlap with dissociative syndrome such as dissociative amnesia.

Methods/results

The cultural formulation interview (CFI) was used for the diagnostic and subsequent treatment of dissociative amnesia with fugue in a different culture patient who met the clinical criteria of this two divergent clinic entities.

Conclusions

In our clinical practice, we will deal with different culture patients, who could present common clinical entities or with the so-called “culture-bound syndromes”. The cultural formulation of the clinical cases will help the clinicians to diagnose and have better treatment's options in clinical manifestations do not correspond to the conventional entities included in mostly Western-based nomenclatures.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Selective serotonine reuptake inhibitors or dual antidepressants and syndrome of inapropriate antidiuretic hormone secretion: A systematic search

Introduction

Depression is a disease with high prevalence all over the world. Selective serotonine reuptake inhibitors (SSRIs) and dual antidepressants (DA) are worldwide used to treat the different types of depressive episodes. Between the adverse events of these compounds, an unusual but potentially severe side effect is the syndrome of inapropriate antidiuretic hormone secretion (SIADH).

Results and discussion

Several cases published, and an amount of cases series have documented the association of SIADH to the use of SSRIs and DA. All SSRIs and DA are at risk of producing SIADH (fluoxetine, paroxetine, fluvoxamine, sertraline, citalopram, escitalopram, venlafaxine and duloxetine). Old age has been found as a risk factor for developing SIADH. There are not enough data to conclude that other risk factors can play a role in the development of this adverse event. Treatment should include the immediate withdrawal of the antidepressant. The introduction of other antidepressants is controversial, as SIADH has been related with all antidepressive treatments; but the risk of relapse into a depressive episode must be considered also. Between symptomatic treatments, the control of water intake and the use of low doses of loop diuretics can be recommended. Severe cases can be treated with higher doses of loop diuretics and saline hypertonic solution.

Conclusions

SIADH has been related with SSRIs and DA antidepressants and it is an infrequent but severe adverse event. Its risk must be considered when prescribing treatment with them. If this adverse event is produced, the substitution of the antidepressant should be done.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Finite element simulation of a local scale air quality model over complex terrain

Abstract. In this paper we propose a finite element method approach for modelling the air quality in a local scale over complex terrain. The area of interest is up to tens of kilometres and it includes pollutant sources. The proposed methodology involves the generation of an adaptive tetrahedral mesh, the computation of an ambient wind field, the inclusion of the plume rise effect in the wind field, and the simulation of transport and reaction of pollutants. We apply our methodology to simulate a fictitious pollution episode in La Palma island (Canary Island, Spain).

[The efficacy of Salmocumarín rodenticide in livestock-raising and urban sites]

The activity in burrows at four different sites was calculated, and it went from 80 to 98% during pretreatment. For the first time in our country, average values of days/deaths of synanthropic rodents in natural conditions were obtained, and the reached values were between 16.50 and 19.06 after applying the biorodenticide. In the statistical analysis, a significant difference was found in the set of objectives related with days/deaths averages (H = 8.60*; p < 0.05). Moreover, no significant differences were found in percentages of residual activity in burrows (G = 8,27; p < 0.05). Results obtained show that Salmocumarín biorodenticide is much more effective in places where great populations of this species of cosmopolitan rodents exist.

Early redox changes during rat thymocyte apoptosis

Methylprednisolone (glucocorticoid hormone, MPS), etoposide (epipodophyllotoxin inhibitor of a topoisomerase II), and thapsigargin (inhibitor of the endoplasmic reticular Ca2+-ATPase) were used as apoptosis-inducing agents in rat thymocytes. Early redox changes were determined during the early phase of induced apoptosis. The three agents induced apoptosis as assessed by DNA laddering after agarose gel electrophoresis and by quantitative DNA fragmentation. Intracellular H2O2 steadystate concentrations after 30 min of incubation were 40, 48, 25, and 75 nM for control and MPS-, etoposide-, and thapsigargin-treated thymocytes, respectively. After 30 min of MPS and thapsigargin exposure, increased DCFH oxidation was clear compared with control cells, but no increase in dichlorofluorescein (DCF) was observed in etoposide-treated thymocytes. DCF fluorescence correlated linearly with the intracellular H2O2 concentration after 30 min of incubation. The amounts of thiobarbituric acid-reactive substances produced after 3 h of incubation and expressed as pmol/mg protein were 105+/-23, 120+/-18, 350+/-17, and 98+/-24 pmol/mg protein for untreated and MPS-, thapsigargin-, and etoposide-treated thymocytes, respectively. Common and marked reductions in intracellular glutathione of 46, 73, 58, and 39% were observed after 2 h of incubation with MPS-, thapsigargin-, and etoposide-treated cells and in untreated cells, respectively. A simultaneous increase in oxidized glutathione, compared with untreated cells, was evident in MPS (66%) and was stronger in thapsigargin-exposed cells (250%). A 55% decrease in GSSG in etoposide-treated cells was found. It is concluded that redox changes occur during the early phase of induced apoptosis in rat thymocytes and are not always associated with an oxidative stress. Rather, this situation is closely related with the type of stimuli.

[Obstetric and gynecologic anesthesia reported in the "Revista Española de Obstetricia y Ginecología" (1916-1936)]

This study follows the evolution of anesthesia in gynecology and obstetrics in Spain between 1916 and 1936. Research included revising all articles and references concerning anesthesiology appearing in the Revista Española de Obstetricia y Ginecologia over the 20 years during which that journal was published. Eighty-three articles were found: 18 (21.6%) original research reports, 37 (44.6%) reviews of the Spanish professional literature and 28 (33.7%) summaries and descriptions of meetings of scientific organizations. Spanish references constituted 39.8% with the remaining 60.2% coming from European and Hispano-American sources. Twenty-four (34.9%) were related to spinal anesthesia, 15 (18%) covered various methods for analgesia during childbirth and 14 (16.8%) were on barbiturates. The remaining articles referred to rectally administered anesthesia, local anesthesia, inhalatory anesthesia and pain in gynecology. In conclusion, our review reveals the strong international contacts in Spanish gynecology during this period, as well as the interest of gynecologists and obstetricians in various anesthetic techniques and the rapid incorporation of new methods into their therapeutic arsenal.

Is Tourette syndrome a cause of sudden infant death syndrome and childhood obstructive sleep apnea?

The cause of sudden infant death syndrome (SIDS) is unknown. Sleep-related impairment of respiratory control and arousal are postulated; hyperdopaminergic and hyposerotonergic dysfunction may contribute to events leading to infant apnea and SIDS. Psychosocial adversity and impulsive and compulsive behaviors characterize some families of SIDS victims. Tourette syndrome (TS) is a common hereditary neurobehavioral disorder characterized by the frequent presence of impulsive and compulsive behaviors. Sleep disorders are common and include sleep apnea and abnormal arousal. Hyperdopaminergic and hyposerotonergic abnormalities are postulated to contribute to the pathophysiology of the disorder. The following is a report of the presence of incidents of infant apnea and SIDS in families in which TS was present. In an additional TS family, a child had obstructive sleep apnea syndrome (OSAS). Results of a preliminary survey suggest that TS gene carriers are at increased risk of life-threatening apneas of infancy and that the prevalence of SIDS in such families may be 2 to 5 times the prevalence in the general population. The presence in some pedigrees of sleep apnea in children and adults suggest that in some instances disorders of sleep-related ventilatory control and arousal occurring throughout the life-span share common pathophysiological mechanisms.

One-piece stockinet for a spica cast

A spica cast is still used for many procedures in surgery, usually on pediatric patients. One of the biggest problems with these is skin care. The authors present an easy, sure way of finishing off the perineal area of a spica cast.