Dinuclear Zn-Catalytic System as Brønsted Base and Lewis Acid for Enantioselectivity in Same Chiral Environment

Zinc (Zn) is a crucial element with remarkable significance in organic transformations. The profusion of harmless zinc salts in the Earth's outer layer qualifies zinc as a noteworthy contender for inexpensive and eco-friendly reagents and catalysts. Recently, widely recognized uses of organo-Zn compounds in the field of organic synthesis have undergone extensive expansion toward asymmetric transformations. The ProPhenol ligand, a member of the chiral nitrogenous-crown family, exhibits the spontaneous formation of a dual-metal complex when reacted with alkyl metal (R-M) reagents, e.g., ZnEt2. The afforded Zn complex possesses two active sites, one Lewis acid and the other Brønsted base, thereby facilitating the activation of nucleophiles and electrophiles simultaneously within the same chiral pocket. In this comprehensive analysis, we provide a thorough account of the advancement and synthetic potential of these diverse catalysts in organic synthesis, while emphasizing the reactivity and selectivities, i.e., dr and ee due to the design/structure of the ligands employed.

Prevalence of migraine and tension-type headache among undergraduate medical students of Kathmandu Valley: A cross-sectional study

Background

Headache is the most prevalent neurological symptom which can be of a serious condition, as in brain tumor, but mostly it is a benign condition that includes primary headache such as migraine or tension-type headache (TTH). Migraine reoccurs frequently and is more severe but owing to the high prevalence of TTH, however, impaired quality of life due to TTH is greater than that of migraine at the population level. Medical students are constantly subjected to stress and in such a condition, it was necessary to find out the burden of headache among medical students. This cross-sectional study done among medical students aims to generate some data and literature which will change the outlook of stakeholders towards headache disorders among medical students.

Methods

This cross-sectional study is based upon Headache Screening Questionnaire-English Version questionnaire based upon the ICHD-3 beta criteria. Medical students of Kathmandu valley were sampled by using convenient sampling and data were collected. Data were refined in Microsoft Excel and imported to SPSS 20 for analysis.

Results

A total of 352 individuals were part of this study, out of which 229 (65.1%) were males and 123 (34.9%) were females with a mean age of 21.72 ±  1.601 years (mean ± SD). Prevalence of migraine and TTH was found to be 15.3% (95% confidence interval [CI]: 11.7%-19.3%) and 40.3% (95% CI: 34.9-45.2), respectively. Through multivariate binomial regression, it was observed that the odds of being diagnosed with migraine increased with age (adjusted odds ratio [AOR] = 1.266 [1.013-1.583], p = 0.038), females had twice the odds of experiencing migraine headaches compared to males (AOR = 2.119 [1.074-4.180], p = 0.03), and medical students who stayed at the hostel were at lesser odds of experiencing migraine headache (AOR = 2.772 [1.501-5.118], p = 0.01).

Conclusion

Prevalence of migraine and TTH among undergraduate medical students was found to be 15.3% and 40.3%, respectively.

Burden of tension-type headache in the Middle East and North Africa region, 1990-2019

Introduction

Tension-type headache (TTH) is the most prevalent neurological disorder. As there is a gap in the literature regarding the disease burden attributable to TTH in the Middle East and North Africa (MENA) region, the aim of the present study was to report the epidemiological indicators of TTH in MENA, from 1990 to 2019, by sex, age and socio-demographic index (SDI).

Methods

Publicly available data on the point prevalence, annual incidence and years lived with disability (YLDs) were retrieved from the global burden of disease (GBD) 2019 study for the 21 countries and territories in MENA, between 1990 and 2019. The results were presented with numbers and age-standardised rates per 100000 population, along with their corresponding 95% uncertainty intervals (UIs).

Results

In 2019, the age-standardised point prevalence and annual incidence rates for TTH in the MENA region were 24504.5 and 8680.1 per 100000, respectively, which represents a 2.0% and a 0.9% increase over 1990-2019, respectively. The age-standardised YLD rate of TTH in this region in 2019 was estimated to be 68.1 per 100000 population, which has increased 1.0% since 1990. Iran [29640.4] had the highest age-standardised point prevalence rate for TTH, while Turkey [21726.3] had the lowest. In 2019, the regional point prevalence of TTH was highest in the 35-39 and 70-74 age groups, for males and females, respectively. Furthermore, the number of prevalent cases was estimated to be highest in those aged 35-39 and 25-29 years, in both males and females, respectively. Moreover, the burden of TTH was not observed to have a clear association with SDI.

Conclusions

While the prevalence of TTH in the MENA region increased from 1990 to 2019, the incidence rate did not change. In addition, the burden of TTH in MENA was higher than at the global level for both sexes and all age groups. Therefore, prevention of TTH would help alleviate the attributable burden imposed on the hundreds of millions of people suffering from TTH around the region.

Validity of the Severity of Dependence Scale for detecting dependence behaviours in chronic migraine with medication overuse

AIMS

In this study, we tested the validity of the Severity of Dependence Scale in detecting dependence behaviours in patients with chronic migraine and medication overuse (CM + MO) using the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and the Leeds Dependence Questionnaire as gold standard measures.

METHODS

Four hundred and fifty-four patients with CM + MO filled in the Severity of Dependence Scale and the Leeds Dependence Questionnaire and underwent a psychological evaluation for the diagnosis of substance dependence according to the DSM-IV criteria.

RESULTS

Sixty-nine percent of subjects (n = 313) presented substance dependence according to the DSM-IV criteria. These patients scored significantly higher than those without substance dependence in Severity of Dependence Scale total score (Z = -3.29, p = 0.001), and in items 1 (Z = -2.44, p = 0.015), 2 (Z = -2.50, p = 0.012), 4 (Z = -2.05, p = 0.04), and 5 (Z = -3.39, p = 0.001). Severity of Dependence Scale total score (β = 0.13, SE = 0.04, z = 3.49, p < 0.001) was a significant predictor for substance dependence. Receiver Operating Characteristic (ROC) curves showed that Severity of Dependence Scale discriminated patients with or without substance dependence.

CONCLUSION

Severity of Dependence Scale could represent an interesting screening tool for dependency-like behaviors in CM + MO patients.

Tension-type headache

Tension-type headache (TTH) is the most prevalent neurological disorder worldwide and is characterized by recurrent headaches of mild to moderate intensity, bilateral location, pressing or tightening quality, and no aggravation by routine physical activity. Diagnosis is based on headache history and the exclusion of alternative diagnoses, with clinical criteria provided by the International Classification of Headache Disorders, third edition. Although the biological underpinnings remain unresolved, it seems likely that peripheral mechanisms are responsible for the genesis of pain in TTH, whereas central sensitization may be involved in transformation from episodic to chronic TTH. Pharmacological therapy is the mainstay of clinical management and can be divided into acute and preventive treatments. Simple analgesics have evidence-based effectiveness and are widely regarded as first-line medications for the acute treatment of TTH. Preventive treatment should be considered in individuals with frequent episodic and chronic TTH, and if simple analgesics are ineffective, poorly tolerated or contraindicated. Recommended preventive treatments include amitriptyline, venlafaxine and mirtazapine, as well as some selected non-pharmacological therapies. Despite the widespread prevalence and associated disability of TTH, little progress has been made since the early 2000s owing to a lack of attention and resource allocation by scientists, funding bodies and the pharmaceutical industry.

Real-life treatment of cluster headache in a tertiary headache center - results from the Danish Cluster Headache Survey

BACKGROUND

Pharmacological treatment of cluster headache constitutes the core of clinical management, but evidence is sparse. We aimed to generate insight in the existing treatment and identify associations between clinical features and treatment response.

METHODS

Patients aged 18-65 diagnosed with cluster headache according to the ICHD-2 completed a questionnaire followed by a structured interview. Multiple logistic regression was used to identify associations.

RESULTS

The population consisted of 400 patients with an episodic: chronic ratio of 1.7:1. Episodic patients were more likely to respond to triptans (odds ratio = 1.77, confidence interval: 1.08-2.91, p = 0.023) and oxygen (odds ratio = 1.64, confidence interval: 1.05-2.57, p = 0.031) than chronic. Oxygen response was less likely if pain intensity was very severe (odds ratio = 0.53, confidence interval: 0.33-2.57, p = 0.006) and the risk of a poor response increased with disease duration (odds ratio = 0.79, confidence interval: 0.65-0.96, p = 0.016). Among current users of sumatriptan injection and oxygen, the proportion achieving 100% relief was higher with sumatriptan injection (p > 0.001) than with oxygen. No associations were identified regarding verapamil. Only 57% of current users of preventive medication responded at a 50% level.

CONCLUSION

Episodic cluster headache is more responsive to acute therapy than chronic. Further, sumatriptan injection was more effective than oxygen and the responder-rate was limited with verapamil. More effective acute and preventive therapies are needed for cluster headache patients.

The Impact of Self-Reported Recurrent Headache on Absenteeism and Presenteeism at Work Among Finnish Municipal Female Employees

Purpose

The aim of this cross-sectional, observational study was to determine the impact of self-reported headache on absenteeism and presenteeism in a female working-age population.

Subjects and Methods

The study population consisted of 594 Finnish female municipal employees, who answered self-administered questionnaires including sociodemographic, lifestyle, health, and work-related data. Sickness absence days were obtained from the official records of the employer. Headache recurrence was defined by asking whether headache was occasional or recurrent. Headache impact was measured by the HIT-6.

Results

In our study, 456 (77%) females had headache, and headache was recurrent in 178 (39%). The self-reported recurrence of headache was related to age, AUDIT-C, health-rated quality-of-life, self-rated work ability, depressive symptoms, and work stress (P for linearity <0.001). They also had more depressive symptoms and work stress (P for linearity <0.001). Mental work load was highest in those with recurrent headache (P=0.042), and work engagement was highest in those without headache (P=0.038). There was no statistically significant difference in absenteeism days between the headache groups when adjusted with confounding variables. Presenteeism was associated with the recurrence of headache (P for linearity <0.001). Presenteeism and the HIT-6 score were significantly associated in the recurrent headache group (P=0.009).

Conclusion

Headache was not related to absenteeism, but the self-reported recurrence of headache was clearly associated with presenteeism in this female working-age population.

The longitudinal association between shift work and headache: results from the Danish PRISME cohort

PURPOSE

We investigated the effect of shift work on headache. Furthermore, we investigated whether the association between shift work and headache was explained by potential mediators in terms of perceived stress, poor sleep and health behaviors.

METHODS

In this longitudinal study, we used questionnaire data (collected in 2007 and 2009) from civil servants and hospital employees from the PRISME study. 2952 individuals were available for the analyses of shift work and headache and 2272 individuals were available for the analyses of shift work and migraine. Headache was operationalized as the participants' experience of "being bothered by headache during the past 4 weeks". Migraine was operationalized as "ever being diagnosed with migraine by a medical doctor". We used binary logistic regression to compare shift workers with permanent day workers and adjusted for socio-demographic factors. In a subsequent step, we adjusted for potential mediators.

RESULTS

We found higher odds of unspecific headache (OR = 1.25; 95% CI 1.02-1.54) and migraine (OR = 1.72; 95% CI 1.04-2.86) among shift workers compared with day workers. Our results suggest that the effect of shift work on headache and migraine differ between men and women. Inclusion of potential mediators in the analyses did not attenuate the associations.

CONCLUSION

Shift workers have higher risk of reporting being bothered by headache as well as reporting being diagnosed with migraine. Future research is needed to disentangle the underlying mechanisms with the aim of reducing headache related to occupational exposures.

Shift work and migraine: A systematic review

OBJECTIVES

Migraine is a chronic neurological disorder characterized by recurrent attacks of headache, mainly affecting the working age population with a great socioeconomic impact. The etiology of migraine is still uncertain, and various individual and/or environmental risk factors have been suggested as triggers of the attacks, including irregularities in the sleep-wake rhythm. In this perspective, it is possible that shift and night work, affecting circadian rhythms, may play a key function in the disease pathogenesis. Therefore, aim of this review was to provide an overview on the possible association between shift works and migraine development or clinical outcomes.

METHODS

A systematic review of literature studies available in Pubmed, Scopus, and ISI Web of Science databases, addressing the possible shift work-migraine relationship was performed.

RESULTS

Conflicting data emerged from the revised studies. Some results supported a positive association between migraine prevalence and shift works, according to peculiar job tasks, seniority in shift works, specific work schedules, and number of night shifts performed in a month. However, other investigations failed to confirm such findings.

CONCLUSIONS

The limited number of available studies, their cross-sectional nature, the different criteria employed for migraine diagnosis, and the various shift work schedules analyzed, together with exposure to other confounding factors on workplace do not allow to extrapolate definite conclusions on shift work-migraine relationship. From an occupational health perspective, further studies appear necessary to better understand such exposure-disease association and possibly define risk assessment and management strategies to protect the health of susceptible and/or migraine affected workers.

Exploration of candidate serum biomarkers potentially related to the chronic pain condition in Medication-overuse headache

Background

Medication Overuse Headache (MOH) is a prevalent and disabling disorder resulting from the overuse of analgesic drugs, triptans or other acute headache medications. In previous proteomic studies, several proteins have been found at high concentrations in the urine of MOH patients and in the serum of rats with neuropathic pain. The aim of this study was to compare the serum levels of lipocalin-type Prostaglandin D2 synthase (L-PGDS), Vitamin D-binding protein (VDBP), apolipoprotein E (APOE) and apolipoprotein A1 (APOA1) in MOH patients and healthy individuals, further exploring their relationship with cutaneous pain thresholds (CPTs) in the territories innervated by the trigeminal nerve.

Methods

Sixty-nine MOH patients and 42 age- and sex-matched healthy volunteers were enrolled in the study. Von Frey-like filaments were applied to the skin territories innervated by the trigeminal nerve, to determine the CPTs. L-PGDS, VDBP, APOE and APOA1 were quantified in the serum by Enzyme-linked Immunosorbent Assay (ELISA). Clinical and laboratory data were collected. Comparisons between MOH patients and healthy individuals were performed using independent t test or χ² test. To correlate serum proteins with CPTs, Pearson correlation coefficient or Spearman’s rank correlation coefficient were used.

Results

CPTs were lower among MOH patients. L-PGDS, VDBP and APOE had significantly different serum concentrations between groups (p < 0.01), but no correlation was found with CPTs. APOA1 serum concentrations did not differ between patients and healthy individuals.

Conclusions

L-PGDS, VDBP and APOE had abnormal serum levels in MOH patients, confirming their alteration in some conditions of chronic headache and neuropathic pain. However, they had no relationship with CPTs. The in-depth study of serum proteins represents a promising approach for a better understanding of MOH, as well as the detection of candidate biomarkers for chronic headache or the risks associated with overuse medications.

Headache Caused by Sinus Disease

Headaches and sinus disease are common reasons to seek medical care, with marked worldwide prevalence and large socioeconomic burdens. Headaches caused by sinus diseases are rare; many "rhinogenic headaches" are actually migraines. The similar symptoms may result from autonomic dysfunction and trigeminovascular pathways. Using the mnemonic ACHE, this article presents key Anatomy, Clinical cases, How to image, Essential clinical and radiographic features that help the radiologist, otolaryngologist, and neurologist evaluate sinus disease and headaches.

The association between shift work and treatment-seeking migraine in Denmark

In Europe, the one-year prevalence of migraine is 14.9% and migraine is on the top-10 list of leading causes of years lost to disability. Sleep disturbances and irregular daily routines are considered triggers of migraine and these factors are well-known consequences of shift work. We studied the association between treatment-seeking migraine and shift work, categorised as fixed evening work, fixed night work and variable working hours with and without night work in a Danish working population of 5872 participants. When compared with fixed day workers, only participants with fixed evening work were found to have significantly increased odds of reporting treatment-seeking migraine after adjustment for socio-demographic and behavioural covariates (OR = 1.56; 95% CI 1.05-2.32). Participants with seniority of 10 years or more notably accounted for this association. Due to the cross-sectional design, selection mechanisms may have biased the results. Practitioner Summary: The study showed higher odds of treatment-seeking migraine among evening workers even when taking a range of potential confounders into account. Due to the cross-sectional design, we cannot draw any causal inferences, but potential mechanisms underlying the present study are discussed, with an emphasis on possible selection into evening work.

Oxygen therapy for cluster headache. A mask comparison trial. A single-blinded, placebo-controlled, crossover study

Purpose The purpose of this article is to investigate possible differences in effect between three types of masks in the acute treatment of cluster headache (CH). Patients and methods Fifty-seven CH patients according to ICHD-II-criteria participated in a single-blinded, semi-randomized, placebo-controlled, crossover inpatient study, and 102 CH attacks were treated with 100% oxygen delivered by demand valve oxygen (DVO), O₂ptimask or simple mask (15 liters/min) or placebo delivered by DVO for 15 minutes. Primary endpoint: Two-point decrease of pain on a five-point rating scale within 15 minutes. Results Only 10 CH patients had multiple attacks and reached the point of placebo. There were no significant differences between masks in the primary endpoints ( p = 0.412). After 15 minutes 48% had a two-point decrease using the DVO compared to 45% with placebo ( p = 0.867). After 30 minutes 68% were pain free or had pain relief using DVO and 45% by placebo ( p = 0.061). The DVO was preferred by 62% compared to 5% and 33% for simple mask ( p < 0.0001) and O₂ptimask ( p = 0.061). In the first attack the DVO was significantly better at achieving pain relief at 15 minutes ( p = 0.018). Treatment with DVO or O₂ptimask reduced the need for rescue medication compared to the simple mask (23%, 19%, 50%, respectively). No treatment-related adverse events were observed. Conclusion The primary endpoint with pain relief at 15 minutes was non-significant; however, a post hoc analysis of the first attack significantly favored DVO. Further, therapy by O₂ptimask and DVO resulted in a decreased need for rescue medication. We recommend that CH patients be offered DVO or O₂ptimask before oxygen therapy is abandoned.

The burden of headache in a patient population from a specialized headache centre

The aim was to characterize the individual and socio-economic impact of headache in a patient population from The Danish Headache Centre. This was a cross-sectional study using a structured interview, prospective headache diaries and standardized self-administered questionnaires using the ICHD-II criteria. Fifty-five subjects (12 male and 43 female) with a median age of 41 years and a median headache frequency of 15 days/month participated. Very high utilization of the healthcare system and a high absence rate due to headache of 12 days/year were reported. Eighty-one percent experienced a marked decrease in work effectiveness. Overall, 91% felt hampered by their headache on a daily basis and 98% had had expenses for headache medication. Frequent headache disorders are highly costly, especially due to indirect costs. Prevention, early intervention or effective treatment strategies for headache disorders may therefore be highly cost effective, not only for the individual but also for society.

The cost-effectiveness of oral triptan therapy in Sweden

The literature suggests that triptans are cost effective compared with older types of migraine treatment. However, which of the triptans that is most cost effective has not been established. We compared the costs and effects of triptan treatment from a Swedish societal perspective, using evidence from the literature. A probabilistic cost-effectiveness model was constructed to investigate the costs and effects of treating a single attack in a typical migraine patient. The end-point used in the base-case analysis was sustained pain free without any adverse events (SNAE). We searched the scientific literature for meta-analyses reporting the efficacy of oral triptans. All treatments except rizatriptan 10 mg and eletriptan 40 mg were dominated. The incremental cost per SNAE of rizatriptan 10 mg compared with eletriptan 40 mg was approximately 100 euro. There was substantial uncertainty concerning the results, but probabilistic analysis showed that rizatriptan 10 mg and eletriptan 40 mg had the highest probability of being cost-effective.

Secular changes in health care utilization and work absence for migraine and tension-type headache: a population based study

OBJECTIVE

To assess changes in consultation rates, medication use and work absences due to migraine and tension-type headache (TTH) in Denmark over a 12-year period.

METHODS

Surveys of the general population in 1989 and 2001. Medical doctors conducted all headache diagnostic interviews based on ICDH-I and II. The participation rate was 76% (740) in 1989 and 74% (711) in 2001. Headache status was categorized as pure migraine, pure frequent TTH (frequent episodic or chronic TTH), coexisting migraine and frequent TTH, and healthy subjects (no primary headache or only infrequent TTH).

RESULTS

Headache-related consultation rates (OR = 1.6 (1.1-2.2)), especially specialist consultations (OR = 3.6 (2.3-5.6)), increased for all headache groups. Use of prescription medication because of headache increased moderately (OR = 2.1 (1.1-3.9)) while the use of prophylactic medication was stable (OR = 1.1 (0.3-4.0)). Both headache-related (OR = 1.1 (0.7-1.7)) and overall (OR = 0.9 (0.7-1.2)) absence rates were largely unchanged. Headache-related absence rates were higher for subjects with both headache types (OR = 7.5 (4.3-13.1)) or with pure migraine (OR = 3.6 (2.0-6.6)) than for subjects with frequent TTH alone. Triptans users had higher migraine headache frequency and tended to have higher absence rates than non-users. Overall absence rates were higher for subjects with both headache types (OR = 2.3 (1.3-4.0)) or with frequent TTH (OR = 1.9 (1.4-2.7)) than for healthy subjects. Pure migraine was not associated with higher overall absence rates (OR = 1.0 (0.6-1.6)).

CONCLUSION

Despite an increase in headache consultation rates and in use of prescription medication and triptans, no improvement in work absence rates was observed. Consultations, medication use, and absence rates were highest for individuals with both migraine and frequent TTH.