Retinoic Acid Signalling in the Pineal Gland Is Conserved across Mammalian Species and Its Transcriptional Activity Is Inhibited by Melatonin

The pineal gland is integral to the circadian timing system due to its role in nightly melatonin production. Retinoic acid (RA) is a potent regulator of gene transcription and has previously been found to exhibit diurnal changes in synthesis and signalling in the rat pineal gland. This study investigated the potential for the interaction of these two systems. PCR was used to study gene expression in mouse and human pineal glands, ex-vivo organotypic cultured rat pineal gland and cell lines. The mouse and human pineal glands were both found to express the necessary components required for RA signalling. RA influences the circadian clock in the brain, therefore the short-term effect of RA on clock gene expression was determined in ex vivo rat pineal glands but was not found to rapidly regulate Per1, Per2, Bmal1, or Cry1. The interaction between RA and melatonin was also investigated and, unexpectedly, melatonin was found to suppress the induction of gene transcription by RA. This study demonstrates that pineal expression of the RA signalling system is conserved across mammalian species. There is no short-term regulation of the circadian clock but an inhibitory effect of melatonin on RA transcriptional activity was demonstrated, suggesting that there may be functional cross-talk between these systems.

Early predictors of disability in paediatric multiple sclerosis: evidence from a multi-national registry

BACKGROUND

Early recognition of markers of faster disability worsening in paediatric-onset multiple sclerosis (MS) is a key requisite of personalised therapy for children with MS at the earliest possible time.

OBJECTIVE

To identify early predictors of rapid disability accrual in patients with paediatric-onset MS.

METHODS

Using the global MSBase registry, we identified patients who were <18 years old at the onset of MS symptoms. The clinico-demographic characteristics examined as predictors of future MS Severity Score (MSSS) included sex, age at symptom onset, absence of disability at the initial assessment, maximum Expanded Disability Status Scale (EDSS) score, relapse frequency and presence of brainstem, pyramidal, visual or cerebellar symptoms in the first year. A Bayesian log-normal generalised linear mixed model adjusted for cumulative proportion of time on higher-efficacy disease-modifying therapies (DMTs) was used to analyse the data.

RESULTS

672 patients (70% female) contributing 9357 visits were included. The median age at symptom onset was 16 (quartiles 15-17) years. Older age at symptom onset (exp(β)=1.10 (95% CI 1.04 to 1.17)), higher EDSS score (1.22 (1.12 to 1.34)) and pyramidal (1.31 (1.11 to 1.55)), visual (1.25 (1.10 to 1.44)) or cerebellar (1.18 (1.01 to 1.38)) symptoms in the first year were associated with higher MSSS. MSSS was reduced by 4% for every 24% increase in the proportion of time on higher-efficacy DMTs (0.96 (0.93 to 0.99)).

CONCLUSIONS

A relatively later onset of MS in childhood, higher disability and pyramidal, visual or cerebellar symptoms during the first year predicted significant worsening in disability in patients with paediatric-onset MS. Persistent treatment with higher-efficacy DMTs was associated with a reduced rate of disability worsening.

New relapse of multiple sclerosis and neuromyelitis optica as a potential adverse event of AstraZeneca AZD1222 vaccination for COVID-19

We report on nine patients (eight cases of MS and one case of NMOSD) who presented a disease relapse in close temporal association with their first AZD1222 vaccination dose against COVID-19. These patients had been stable for a median period of six years, with no evidence of disease activity and no change in their medication. After a median of 13 days (7 to 25 days) from vaccination, they developed a new relapse with increased disability and new lesions on magnetic resonance imaging. Although this association may be rare, it might be an adverse event of AZD1222.

Coronavirus disease 2019 in Latin American patients with multiple sclerosis

Patients with multiple sclerosis (MS) who present coronavirus disease 2019 (COVID-19) are of particular interest to neurologists. These patients have a neuroimmune disease and receive immunomodulatory or immunosuppressive therapies in the long-term. We present here data from 73 patients with MS and a confirmed diagnosis of COVID-19 from five Latin American countries. Fifteen patients (20.5%) were hospitalized and two patients died. The use of anti-CD20 therapies was the only risk factor associated to hospitalization and death. Despite the small sample size, this study highlights the awareness regarding therapeutic options for MS during the pandemic.

COVID-19 in a temporal relation to the onset of multiple sclerosis

Neurological complications of COVID-19 have been described. We present the case of a 27-year-old woman who developed COVID-19 in April 2020. She continued to present anosmia and ageusia eight months later. Six months after contracting COVID-19, she developed dysesthesia, hypoesthesia and hyperreflexia. Her magnetic resonance imaging showed demyelinating lesions, of which two were enhanced by gadolinium. She was positive for oligoclonal bands in her spinal fluid. This patient developed multiple sclerosis with a temporal relationship to COVID-19. We believe that SARS-CoV-2 led to her autoimmune disease through a virus-induced neuroimmunopathological condition.

Practical Issues Concerning the Approval and Use of Biosimilar Drugs for the Treatment of Multiple Sclerosis in Latin America

The use of biosimilar drugs for multiple sclerosis (MS) has become widespread in Latin America, with the goal of reducing costs of treatments, promoting the sustainability of healthcare systems, and improving patient access to these therapies. There is currently a need to define and comply with requirements to guarantee the efficacy, safety, and quality of these drugs. Thus, the objective of the present study was to compile up-to-date information from each Latin American country assessed on (a) approval of biosimilar drugs by regulatory agencies; (b) use of biosimilar drugs, pharmacovigilance plans, risk management; and (c) update in the knowledge on different molecules. To do so, a group of experts from Argentina, Bolivia, Brazil, Chile, Colombia, Costa Rica, Ecuador, Mexico, Panama, Peru, Uruguay, and Venezuela met to discuss the current situation regarding good practices and risks associated with the use of biosimilar drugs in their respective countries. Regulation, risk management plans, and pharmacovigilance in the whole continent must guide the strategies on the commercialization and access of biosimilar drugs and copies of complex molecules. Current regulations must be implemented for the registration of biosimilar drug products and complex molecules. It is paramount to ensure that new products follow the best quality standards at all stages beyond being safe and efficient. Uncontrolled interchangeability between original biological and biosimilar should be avoided. Latin America requires the implementation and full use of strong pharmacovigilance programs. National and multinational clinical studies are required to demonstrate the similarity in safety, efficacy, and immunogenicity profiles of complex molecules, as well as biological and biosimilar products. Plain language summary available for this article.

Profile and costs involved in long-term compulsory hospitalization of psychiatric patients

Objective:

Involuntary hospitalization for acute psychiatry cases can be acceptable when there is potential harm. However, there are few reasons for a patient committed on these grounds to stay in an institution for a long period. The objective of the present study was to identify the profile and costs of compulsory hospitalizations over 20 days in a public psychiatric hospital in the coastal region of the state of São Paulo.

Methods:

Retrospective data were collected from the medical records of 1,064 patients admitted between July 2013 and June 2016 from an intensive mental healthcare unit in Santos, state of São Paulo, Brazil.

Results:

Records were found of 527 patients who had been hospitalized for at least 21 days during the study period. Long-term hospitalization related to judicial mandates represented 5.9% of the total sample. These patients stayed in the hospital for an average period of 142 days, while patients hospitalized for any other reason stayed an average period of 35 days (p < 0.001). The cost of a long-term court-ordered hospitalization averaged US$ 21,311 per patient.

Conclusion:

Judicial mandate has been an important reason for the long-term hospitalization of chronic psychiatric patients in Santos, Brazil.

Specificities of Children with Multiple Sclerosis and Neuromyelitis Optica

BACKGROUND

Chronic demyelinating diseases of the central nervous system (CNS) are autoimmune conditions that, although rarely fatal, may lead to severe disability. Among these diseases, Multiple Sclerosis (MS) and neuromyelitis optica (NMO) are particularly important and subject of worldwide research. MS and NMO are chronic types of CNS disease, with recurrent episodes of demyelination. For many years, these two conditions were considered to be only one, but lately it is known that they have different epidemiological, physiopathological and prognostic characteristics. The present study aims at reviewing the specificities of MS and NMO affecting patients before they complete 18 years of age.

METHODS

Literature review on data about MS and NMO in patients below the age of 18 years.

RESULTS

There are no clinical trials for any drug used to treat MS and NMO in children or adolescents. Data are mainly on anedoctal cases, case series and recommendations from experts. At present, there is no evidence-based treatment to be recommended for patients with MS and NMO before the age of 18 years.

CONCLUSION

Despite being a particularly vulnerable population for severe disability in the future, there are no evidence-based guidelines for the treatment of MS and NMO in children and adolescents.

Differential diagnosis of multiple sclerosis in Latin America

Improvement of multiple sclerosis (MS) diagnoses leads to earlier and correct disease management. The differential diagnostic workup for MS comprises a large variety of medical conditions. There are general guidelines and criteria for diagnosing MS worldwide, but awareness of regional differences needs to be kept in mind. Latin American patients who are screened for MS diagnoses may require an approach that is not exactly the same as that used for patients in North America, western Europe or Asia. In the present review, the conditions that are important for the differential diagnoses of MS in Latin America are reviewed. They include infections, metabolic diseases, nutritional deficits and other autoimmune conditions that physicians in charge of these patients need to be familiar with.

Cost analysis of multiple sclerosis in Brazil: a cross-sectional multicenter study

Background

Multiple sclerosis (MS) is a central nervous system disease associated with irreversible progression of disability, which imposes a substantial socioeconomic onus. The objective of this study was to determine the economic impact of multiple sclerosis from the Brazilian household and healthcare system perspectives. Secondary objectives were to assess the impact of fatigue on daily living and health-related quality of life (HRQL) of MS patients.

Methods

This is a cross-sectional study in which Brazilian eligible patients attending eight major MS specialized sites answered an interview capturing data on demographics, disease characteristics and severity, comorbidities, resource utilization, fatigue, utilities and health-related quality of life from November/2011 to May/2012 . Costs were assessed considering a prevalence-based approach within 1 year of resource consumption and were estimated by multiplying the amount used by the corresponding unit cost. Patients were classified as having mild, moderate or severe disability according to the Expanded Disability Status Scale (EDSS).

Results

In total, 210 patients who met eligibility criteria were included, 40 % had mild, 43 % moderate and 16 % severe disability; disability level was missing for 1 %. The average total direct cost per year was USD 19,012.32 (SD = 10,465.96), and no statistically significant differences were not observed according to MS disability level (p = 0.398). The use of disease modifying therapies (DMTs) corresponded to the majority of direct expenditures, especially among those patients with lower levels of disability, representing around 90 % of total costs for mild and moderate MS patients. It was also observed that expenses with medical (except DMTs) and non-medical resources are higher among patients with more severe disease. Worsening disability also had an important influence on health-related quality of life and self-perceived impact of fatigue on daily living.

Conclusion

Our data demonstrates the significant economic impact of MS on both Brazilian household and health system, in terms of DMTs and other disease management costs. When patients move upwards on the disease severity scale, costs with health resources other than drugs are significantly increased.

The expression and roles of Nde1 and Ndel1 in the adult mammalian central nervous system

Mental and neurological illnesses affect one in four people. While genetic linkage analyses have shown an association of nuclear distribution factor E (NDE1, or NudE) and its ohnolog NDE-like 1 (NDEL1, or Nudel) with mental disorders, the cellular mechanisms remain unclear. In the present study, we have demonstrated that Nde1 and Ndel1 are differentially localised in the subventricular zone (SVZ) of the forebrain and the subgranular zone (SGZ) of the hippocampus, two regions where neurogenesis actively occurs in the adult brain. Nde1, but not Ndel1, is localized to putative SVZ stem cells, and to actively dividing progenitors of the SGZ. The influence of these proteins on neural stem cell differentiation was investigated by overexpression in a hippocampal neural stem cell line, HCN-A94. Increasing Nde1 expression in this neural stem cell line led to increased neuronal differentiation while decreasing levels of astroglial differentiation. In primary cultured neurons and astrocytes, Nde1 and Ndel1 were found to have different but comparable subcellular localizations. In addition, we have shown for the first time that Nde1 is heterogeneously distributed in cortical astrocytes of human brains. Our data indicate that Nde1 and Ndel1 have distinct but overlapping distribution patterns in mouse brain and cultured nerve cells. They may function differently and therefore their dosage changes may contribute to some aspects of mental disorders.

Astrocytes as a regulated source of retinoic acid for the brain

Retinaldehyde dehydrogenases (RALDH) catalyze the synthesis of the regulatory factor retinoic acid (RA). Cultured astrocytes express several of the RALDH enzyme family, and it has been assumed that this can be extrapolated to astrocytes in vivo. However, this study finds that few astrocytes in the rodent brain express detectable RALDH enzymes, and only when these cells are grown in culture are these enzymes upregulated. Factors controlling the expression of the RALDHs in cultured astrocytes were explored to determine possible reasons for differences between in vitro versus in vivo expression. Retinoids were found to feedback to suppress several of the RALDHs, and physiological levels of retinoids may be one route by which astrocytic RALDHs are maintained at low levels. In the case of RALDH2, in vivo reduction of vitamin A levels in rats resulted in an increase in astrocyte RALDH2 expression in the hippocampus. Other factors though are likely to control RALDH expression. A shift in astrocytic RALDH subcellular localization is a potential mechanism for regulating RA signaling. Under conditions of vitamin A deficiency, RALDH2 protein moved from the cytoplasm to the nucleus where it may synthesize RA at the site of the nuclear RA receptors. Similarly, in conditions of oxidative stress RALDH1 and RALDH2 moved from the cytoplasm to a predominantly nuclear position. Thus, the RALDHs have been revealed to be dynamic in their expression in astrocytes where they may maintain retinoid homeostasis in the brain.

Towards establishing MS prevalence in Latin America and the Caribbean

A very high prevalence of multiple sclerosis (MS) has been reported in some Western European and North American countries. The few surveys of MS epidemiology in South America reveal lower prevalence rates, implying that susceptibility varies between distinct ethnic groups, thus forming an important determinant of the geographic distribution of the disease. The objective of this study is to review MS prevalence estimates in different Latin American and Caribbean countries. We reviewed surveys of regional MS prevalence from 1991 to 2011. Sources included an online database, authors' reports and proceedings or specific lectures from regional conferences. We obtained a total of 30 prevalence surveys from 15 countries, showing low/medium MS prevalence rates. Both the number and the quality of prevalence surveys have greatly improved in this region over recent decades. This is the first collaborative study to map the regional frequency of MS. Establishment of standardized methods and joint epidemiological studies will advance future MS research in Latin America and the Caribbean.

What can we really tell women with multiple sclerosis regarding pregnancy? A systematic review and meta-analysis of the literature

BACKGROUND

Although several papers report on pregnancy and multiple sclerosis (MS), no systematic review of the literature has been carried out. Neurologists and obstetricians need to have proper information to discuss with women presenting with MS who consider pregnancy.

OBJECTIVES

Literature review and meta-analysis of data on pregnancy in women with MS.

SEARCH STRATEGY

The present work followed the recommendations of the PRISMA Statement. Using the PICO framework, the authors independently searched for the terms 'pregnancy' OR 'gestation' OR 'pregnant' AND 'multiple sclerosis' OR 'MS' in the following databases: EMBASE/Excerpta Medica, Medline, Pubmed, Scopus, Index Medicus, Biomed Central, Ebsco Fulltext, LILACS, Scielo and the Cochrane Database of Systematic Reviews.

SELECTION CRITERIA

only papers presenting original work with analysis of at least one of the outcomes among pregnant women with MS were included.

DATA COLLECTION AND ANALYSIS

Two independent workers performed the literature review. All the authors selected and read the relevant papers. Two other authors summarised data for analysis.

MAIN RESULTS

Twenty-two papers reporting on 13,144 women with MS and their pregnancies were analysed. A significant decrease in relapse rate was observed during pregnancy, followed by a significant increase after delivery. Miscarriages, low birthweight, prematurity, neonatal death and malformations were assessed among these women and their offspring. There seems to be a regional influence on the rates of caesarean sections and abortions among women with MS. Neonatal death and malformation rates did not seem to be particularly high.

AUTHORS' CONCLUSIONS

The present work provides evidence-based data that can be discussed with women with MS and their relatives when pregnancy is considered by these families.

Odors as triggering and worsening factors for migraine in men

OBJECTIVE: To assess the role of odors in triggering or worsening migraine in men. METHOD: Ninety-eight male migraineurs from the general population were assessed individually through questionnaires. Environmental factors relating to their migraine were reported, with special focus on the role of odors. RESULTS: Odors were the second most frequent triggering factor for migraine attacks (48%), behind stressful situations (59%). Likewise, odors were the second most frequent worsening factor (73%), just behind excessive light (74%). Thirty-three individuals (33.4%) stated that odors were both triggering and worsening factors for their migraine attacks. Perfume, cigarette smoke and cleaning products were the most frequent migraine-related odors reported by these male migraineurs. CONCLUSION: This was the first study to assess the role of odors in migraine exclusively in men. There was a high degree of odor-related migraine among these men, thus suggesting that patient education could alert such individuals to gender-related factors, since different triggering and worsening factors have been reported by males and females.

Efficacy and safety of metamizol vs. acetylsalicylic acid in patients with moderate episodic tension-type headache: a randomized, double-blind, placebo- and active-controlled, multicentre study

We assessed the efficacy and safety of oral single doses of 0.5 and 1 g metamizol vs. 1 g acetylsalicylic acid (ASA) in 417 patients with moderate episodic tension-type headache included in a randomized, double-blind, placebo- and active-controlled, parallel, multicentre trial. Eligibility criteria included 18-65 years of age, history of at least two episodes of tension-type headache per month in the 3 months prior to enrollment, and successful previous pain relief with a non-opioid analgesic. Treatment arms were metamizol 0.5 g (n = 102), metamizol 1 g (n = 108), ASA 1 g (n = 102) and placebo (n = 105). The analgesic efficacy of 0.5 and 1 g metamizol vs. placebo was highly statistically significant (alpha: 0.025; one-sided) for sum of pain intensity differences, maximum pain intensity difference, number of patients with at least 50% pain reduction, time to 50% pain reduction, maximum pain relief and total pain relief. A trend towards an earlier onset of a more profound pain relief of 0.5 and 1 g metamizol over 1 g ASA was noticed. All medications including placebo were almost equally safe and well tolerated.

Low doses of gabapentin may be helpful in the management of chronic daily headache

CONTEXT

The difficult management of chronic daily headache and the lack of clinical trials for this medical condition led the authors to perform this study. Gabapentin has been successfully used for a variety of chronic pain conditions and therefore may be of use in the treatment of chronic headache.

OBJECTIVE

To assess the efficacy and safety of low doses of gabapentin in cases of chronic daily headache.

DESIGN

Open-label study on a series of cases of chronic daily headache.

PATIENTS

Twenty-one consecutive patients with primary headache lasting 4 or more hours a day, at least 15 days per month, were invited to participate in this open trial. They were treated with low doses of gabapentin for sufficient time to lead to a headache-free period of at least 7 consecutive days. A minimum of 1 follow-up visit and 1 phone call were made in the subsequent 6-9 months.

MEASUREMENTS

A simple "Patient Impression of Change" was used to evaluate the results. Patients were also invited to compare this treatment to previous ones, whenever possible.

RESULTS

The efficacy of the treatment with gabapentin was rated as "excellent" by 19% of the patients, "good" by 47.6%, "fair" by 19%, and "poor" by 14.4%.

CONCLUSIONS

Despite the inherent limitations of such a small open trial, the authors concluded that ratings of excellent and good by two thirds of this population of patients with chronic daily headache should encourage the setup of a large double-blind, multicentric, placebo-controlled trial of low doses of gabapentin for chronic daily headache.

[Hemicrania continua]

OBJECTIVE: To report a case of Hemicrania Continua in a female aged 17, who presented this kind of headache for 9 years without diagnosis. Although this may be a relatively rare primary headache, the immediate response to clinical treatment with indomethacin justifies this entity be better known. METHODS: Case report of a female adolescent who had presented Hemicrania Continua for many years, without diagnosis and adequate treatment. Review of the relevant medical literature by means of Medline. RESULTS: Treatment with low doses of indomethacin caused complete cessation of the headache. CONCLUSION: Hemicrania Continua must be considered as a diagnostic possibility for patients who present continuous unilateral headache, without abnormalities in the clinical, neurologic and laboratorial examination, irrespective of the age the headache starts. This is the youngest patient reported to have Hemicrania continua and it was brought to discussion by a medical student, aware of this possible diagnosis.

Hemicrania continua with onset at an early age

The authors describe the case of an adolescent who had suffered from unilateral continuous headache since she was 8 years old. Treatment with indomethacin 50 mg/day promptly relieved the pain which had affected her for the previous 9 years. To the best of our knowledge, this is the earliest onset of hemicrania continua reported.

In vivo metabolism of alpha-tocopherol in lipoproteins and liver: studies on rabbits in response to acute cholesterol loading

OBJECTIVE

To investigate the transport of alpha-tocopherol in lipoproteins of rabbits under normal diet and under acute loading of cholesterol.

DESIGN

Two New Zealand White rabbits were fed 14C-alpha-tocopherol acetate in a single oral dose and the recovery of radiolabel in lipoproteins and plasma was monitored. Low density lipoprotein (LDL) from these animals was obtained and labeled with [3H] cholesteryl ester. Three other rabbits were injected with this double-labeled LDL in the native form; while three other animals received this LDL in the acetylated form.

RESULTS

Plasma clearance, liver uptake and levels of radiolabel in high density lipoprotein (HDL) of animals injected with 14C[3H]acetyl LDL were significantly higher than those in animals injected with 14C[3H]native LDL. Larger particles of HDL, rich in apolipoprotein E (apoE) carried significantly higher levels of both labels in rabbits injected with acetylated LDL.

CONCLUSION

These results provide evidence for in vivo mechanisms of "reverse alpha-tocopherol transport", analogous to "reverse cholesterol transport".

Neurologic manifestations of AIDS: a review of fifty cases in Santos, São Paulo, Brazil

OBJECTIVE

To review the neurologic manifestations of AIDS in patients who were admitted to Hospital Guilherme Alvaro (HGA) due to any clinical manifestation of the disease.

DESIGN

Case series.

PATIENTS

All HIV+ patients admitted to the Faculty Hospital (HGA) between July 96 and April 97 were included in this review.

RESULTS

From the 117 HIV+ patients admitted to hospitalization due to AIDS-related symptoms, 50 (42.7%) presented neurologic manifestations. The most prevalent of these was neurotoxoplasmosis (68%), but a variety of other neurologic diseases were observed. Only 36% of these 50 patients had neurological signs and symptoms as the main complaint for admission, 12% of the patients had at least complained of some neurologic dysfunction at the time of admission and 10% had no neurologic complaints at all. The remaining 42% (21 patients) only complained of neurologic manifestations of AIDS when specifically asked.

CONCLUSIONS

The prevalence of neurologic manifestations of AIDS is very high in patients admitted to hospital. Even in the absence of neurologic-related complaints, these patients have to be carefully questioned and examined in the search for an underlying neurologic complication which may present high morbidity and mortality.

Management of primary headache in emergency services of Santos and surrounding towns

OBJECTIVES

Primary headaches are often seen by Clinicians on duty at Emergency Services. We have investigated the treatment of such patients by 43 medical doctors who have been working at Emergency Services in the city of Santos and surrounding towns for many years.

RESULTS

We confirmed the high prevalence of primary headaches in Emergency Services. There seem to be diagnosis difficulties concerning differentiating attacks of migraine and tension type headache. We also observed that IV dipirone was the most frequently prescribed treatment for patients with primary headaches in this study. There is no protocol in the literature which recommends IV dipirone for the treatment of migraine attacks or other primary headaches.

CONCLUSION

It would be advisable to perform controlled double blind studies in order to verify the advantages of IV dipirone in the treatment of intense attacks primary headaches. We concluded that headache management recycling programs could be of interest for doctors who regularly work at Emergency Services.

Reduction of migraine attacks during the use of warfarin

Two recent reports on reduction of migraine attacks during treatment with vitamin K antagonists have caught my attention. Being a migraine sufferer myself, with considerable improvement of my headache during the use of warfarin, I became interested in the subject. Recently, a young man sought my advice for migraine attacks which had worsened after the withdrawal of warfarin. The previous reports on migraine and warfarin involved elderly patients. I report now on these two patients in their 30s, one of them being myself (case 1), who have experienced reduction of migraine attacks during the use of warfarin.

Cholesterol-loading of peripheral tissues alters the interconversion of high density lipoprotein subfractions in rabbits

High density lipoprotein (HDL) has been implicated in the process of reverse cholesterol transport,by which surplus cholesterol is removed from peripheral tissues and transported to the liver for excretion. It has been suggested that some subfractions of HDL may have a particular role in this process, though the underlying mechanism remains unclear. The present study was aimed at investigating the role of specific subfractions of HDL in reverse cholesterol transport. The interconversion of HDL subfractions in normal and cholesterol-loaded rabbits was studied in vivo. Rabbit HDL was separated by heparin-Sepharose affinity chromatography into six subfractions (HDL(I)-HDL(VI)), which were progressively enriched with apolipoprotein E (apo E), and varied in diameter and composition. Total HDL and its subfractions were individually labelled with 14C sucrose and injected in the rabbits. When rabbits which were not acutely loaded with [3H]cholesterol were injected with 14C-HDL(I), 70% of the label remained in this fraction while less than 5% was recovered in HDL(VI), containing the largest particles and those most enriched in apo E. No label was detectable in the liver of these animals. In rabbits which had received a prior loading of cholesterol, an average of only 18.3% of the 14C label was present in HDL(I) while approx. 40% of the label was recovered in HDL(VI). On average, 5.1% of the total 14C injected in these rabbits was recovered in the liver. It is concluded that two alternative routes for reverse cholesterol transport may be operative. While a continuous cholesterol-clearance route may be provided by particles of HDL of intermediate size, another route may be operative for clearance of excess cholesterol loaded into peripheral endothelial cells.

Uptake of apolipoprotein E-rich and apolipoprotein E-poor subfractions of high-density lipoprotein by liver membranes and HepG2 cells

Apolipoprotein (apo) E plays an important role in mediating high-density lipoprotein (HDL) cholesterol transport and uptake by the liver. Evidence for and against the existence of conventional liver receptors for HDL containing apoE have been reported, although the selective uptake of the cholesterol moiety of HDL has been demonstrated. The present study investigated the hepatic uptake of subfractions of HDL separated on the basis of their apoE content. Rabbit HDL and its apoE-rich and apoE-poor subfractions, separated by heparin-Sepharose affinity chromatography, were labelled in their apoprotein moieties with [14C]sucrose and in their cholesteryl ester moiety with 3H. No binding of either subfraction to rabbit liver membranes could be detected. With cultured HepG2 cells, however, there was a high uptake of 3H but a very low uptake of 14C from both HDL subfractions, demonstrating that selective uptake was operating. Addition of unlabelled apoE-poor HDL inhibited the uptake of both labels from the two subfractions to the same extent. These studies, which differed from previously reported investigations by employing native homologous HDL subfractions of known apolipoprotein composition, demonstrated that apoE is not directly involved in the selective uptake of HDL cholesterol by the liver. In the absence of specific binding sites on liver membranes, it is suggested that an alternative mechanism might exist for the clearance of HDL cholesterol from the plasma.

Tocopherols and carotenes are differently distributed in subfractions of high-density lipoprotein

An apolipoprotein (apo) E-rich and an apo E-poor fraction of high-density lipoprotein (HDL) were isolated from four healthy men by heparin-Sepharose affinity chromatography. On a cholesterol basis, the apo E-poor HDL fraction contained a third more alpha- and gamma-tocopherol and about a third less alpha- and beta-carotene than the apo E-rich HDL fraction. Plasma concentrations of HDL cholesterol were highly correlated with the contribution of the apo E-rich HDL subfraction to total HDL alpha-tocopherol (r = -0.990, P < 0.001).

The role of subfractions of high density lipoprotein in the in vivo transport of cholesterol from cholesterol-loaded hepatic and peripheral endothelial cells in the New Zealand white rabbit

1. High density lipoprotein (HDL) of the New Zealand White rabbit was separated by heparin-Sepharose affinity chromatography into six distinct subfractions of different composition and particle size. 2. When human acetyl LDL containing [3H]cholesteryl linoleate was injected intravenously into rabbits to prime the endothelial cells with labelled cholesterol, only 1-2% of the radioactivity remained in the plasma after 2 hr. 3. After 4 hr, 60.1% of the plasma radioactivity was present in HDL and 25% of this was recovered in the largest particles of HDL (fraction VI, mean particle diameter 11.6-11.8 nm). 4. The concentration of these largest particles of HDL, rich in apolipoprotein E, were also relatively increased in acetyl-LDL-treated rabbits when compared to controls (P < 0.01). 5. In control in vitro experiments, 62.2% of the radioactivity recovered in HDL was associated with subfractions IV and V (mean particle diameter 10.2-10.8 nm) while only 5% was present in fraction VI. 6. The results show that large HDL particles enriched with apo E contain a large proportion of cholesterol previously supplied to hepatic and peripheral endothelial cells. 7. This study demonstrated that the rabbit provides a useful animal model for the study of the metabolism of subfractions of HDL in relation to reverse cholesterol transport.

The effect of gammalinolenic acid on the subfractions of plasma high density lipoprotein of the rabbit

The effect of dietary supplementation with evening primrose oil (containing 70% gammalinolenic acid) on the concentration of plasma lipids and lipoproteins of the New Zealand White rabbit was investigated. No significant changes were observed in the concentrations of plasma cholesterol or triglycerides during the treatment, although an increase in high density lipoprotein (HDL) cholesterol (P < 0.01) was observed at 4 weeks of evening primrose oil intake and 2 weeks after withdrawal. However, when HDL subpopulations were resolved by gradient gel electrophoresis, major alterations were observed in the distribution of HDL subfractions. These included an increase in HDL2b (P < 0.001) and HDL3c (P < 0.001) and the appearance of very large particles of HDL. These findings suggest that supplementation of diets with n-6 fatty acids may be effective in the long-term prevention of atherosclerosis.

Cluster headache: phospholipid metabolism in polymorphonuclear cells

Our group has previously reported significant changes in the incorporation of precursors into glycerophospholipids, particularly phosphatidylserine, in polymorphonuclear cells obtained from the peripheral blood of cluster headache patients, when compared with controls. The potential of these results led to further work using both the previous methodology and a modified isolation technique to obtain polymorphonuclear cells in as pure a state as possible. Neither the new results obtained using the original technique, nor the results with high purity polymorphonuclear cells from controls and cluster headache patients, confirm the marked changes in precursor uptake into glycerophospholipids originally reported.

Cluster headache: incorporation of (1-14C)oleic acid into phosphatidylserine in polymorphonuclear cells

As recently demonstrated by our group, polymorphonuclear cells (PMNs) from cluster headache patients have an increased ability to incorporate arachidonic acid (AA) and L-serine into phosphatidylserine (PS). To evaluate whether there is an increased incorporation into PS also from fatty acids not involved in eicosanoid metabolism, PMNs from controls (n = 14) and cluster headache patients (n = 12) were incubated with (1-14C)oleic acid. After 1 h 2.7% +/- 1.1 (mean value +/- SD) of the glycerophospholipid radioactivity was found in PS in controls, whereas 4.2% +/- 1.2 was found in cluster headache patients (p less than 0.005). For phosphatidylcholine (PC) the corresponding figures were 74.2 +/- 5.4 in controls and 66.7 +/- 7.6 in cluster headache patients (p less than 0.01). The results suggest that the de novo biosynthesis of PS is increased and the biosynthesis of PC is decreased in cluster headache. The results may have an effect on the role of PS as an obligate protein kinase C activator.

Increased incorporation of L-(U-14C)serine into phosphatidylserine in polymorphonuclear cells from cluster headache patients

It has recently been demonstrated by our group that polymorphonuclear cells (PMNs) from cluster headache patients incorporate more arachidonic acid (AA) into phosphatidylserine (PS) than PMNs from controls. In the present report, the incorporation of L-(U-14C)serine into PS in PMNs from 14 healthy volunteers and 12 cluster headache patients was studied. PMNs from controls incorporated 1194 +/- 578 (mean +/- SD) cpm of L-(U-14C)serine into PS, 268 +/- 292 cpm into phosphatidylethanolamine, and 57 +/- 71 cpm into sphingomyeline. The corresponding figures in cluster headache patients were 2365 +/- 841 cpm, 291 +/- 207 cpm, and 88 +/- 66 cpm, respectively. Incorporation of L-(U-14C)serine into PS was significantly increased (p less than 0.0004) in PMNs from cluster headache patients, whereas no significant difference was seen in other lipids. The results confirm that patients with cluster headache have an increased incorporation of precursors into PS in isolated PMNs, and they indicate that this is due to an increased de novo synthesis of PS.

Cluster headache: increased incorporation of (1-14C)arachidonic acid into phosphatidylserine in polymorphonuclear cells

Vasoactive metabolites deriving from arachidonic acid (AA) have been considered as putative mediators in the pathogenesis of various types of headache. In the present study we therefore compare the ability to synthesize AA containing precursor phospholipids in polymorphonuclear cells (PMNs) from healthy controls and cluster headache patients. 3.7% +/- 1.4 (mean +/- SD) of the (1-14C)AA incorporated into total PMN glycerophospholipids (GPLs) was recovered in the phosphatidylserine (PS) in a group of cluster headache patients (n = 12). This was almost twice the value of 1.9% +/- 0.8% found in a corresponding group of 24 healthy controls (p less than 0.001). A significant decrease in the incorporation of (1-14C)AA into phosphatidylcholine (PC) (p less than 0.01) and an increase in the incorporation of (1-14C)AA into phosphatidyletanolamine (PE) (p less than 0.05) were also found in cluster headache patients when compared to the control group. The increased incorporation of (1-14C)AA into PS in PMNs from this group of patients is interesting because PS plays an important role in the activation of protein kinase C, an enzyme involved in transmembrane signalling. The clinical implications of the present findings in cluster headache, if any, cannot yet be defined.

Cluster headache: on the significance of so-called minibouts

Cluster headache periods (bouts) have, at the lower end of the scale, been supposed to last for periods as short as 1-2 weeks. Patients who usually have bouts of ordinary duration occasionally have brief attacks in the remission phase ("abortive attacks"). The group described here had a temporal pattern, clearly at variance with both these patterns: The six patients had mostly or entirely bouts of less than 1 week's duration. We have termed such short-lasting bouts minibouts, on the supposition that such cases belong within the cluster headache cycle. All the patients were men and had a history of unilateral headache without side shift, and usually the solitary attacks had some autonomic accompaniments, although of a moderate degree. In four cases only mild attacks occurred, whereas in two cases the attacks were rather severe and not consistent with full working ability. The group as such may not be homogeneous. The nosologic status of patients with bouts lasting only 1-2 days is somewhat uncertain. As long as the substrate of cluster headache is not outlined, the lower end of duration of minibouts cannot be accurately identified. The fact that three patients recently have experienced bouts of ordinary length strengthens the view that such cases really belong to the cluster headache cycle.

Arachidonic acid metabolism in polymorphonuclear cells in headaches. A methodologic study

Prostaglandins and leukotrienes have been implicated in the pathogenesis of various types of headache, mainly because some, but not all, cyclo-oxygenase inhibitors are effective in their treatment. We have therefore investigated whether a pathologically changed turnover of arachidonic acid (AA)-containing phospholipids can be seen in headache patients, using isolated polymorphonuclear cells (PMNs) from healthy controls and patients with chronic paroxysmal hemicrania (CPH) and cluster headache. PMNs from healthy controls incorporated 55% of the added (1-14C)AA into total lipids, and 0.5% +/- 0.14% of this radioactivity was found in the phosphatidylserine (PS) fraction. PMNs from a cluster headache and a CPH patient showed 300% and 900% increase in PS labeling from AA, respectively. No other phospholipids showed any difference between controls and patients. The results are discussed in connection with membrane signal transduction via the PS-dependent protein kinase C.

Cluster headache: further observations on the dissociation of pain and autonomic findings

A 51-year-old male cluster headache patient had during five bouts in the course of 11 years always had the headache attacks on the left side. Autonomic abnormalities were, however, present on the right side. Pupillometrically, there was thus a Horner-like syndrome on the right (non-symptomatic) side, with miosis and a relatively more marked dilatation of that eye subsequent to topical application of a directly working sympathomimetic agent (phenylephrine) than after an indirectly working one (hydroxyamphetamine), whereas this was not the case on the symptomatic side. The findings on evaporimetry were not as clear-cut as the pupillometric findings; however, even facial sweating was consistent with a pathologic condition on the right (non-symptomatic) side. A primary dichotomy of pain and autonomic signs (that is, not due to change of side of pain localization) thus seems to be present in this case.

Cluster headache-like headache, Hageman trait deficiency, retrobulbar neuritis, and giant aneurysm. Autonomic function studies

A 56-year-old, previously reported woman with cluster headache-like headache with bouts of unilateral (the side of predominance changing through the years) severe headache had a familial history (three generations) of partial Hageman factor deficiency and bleeding episodes. A giant aneurysm was found to be lodged in the anterior communicating artery on the left side. Clinically, the features were atypical for cluster headache: onset at a young age (14 years), episodes of retrobulbar neuritis appearing at the side of pain, etc. Studies of forehead sweating indicated that the right side was the pathologic one, from an autonomic point of view, as did pupillometric studies. However, during attacks, which were left-sided at the time, forehead sweating was marked laterally on the left side and on the upper eyelid, but not on the right. The "signal" usually reaching the autonomically stigmatized side during attacks of cluster headache, therefore, did not seem to reach the sweat glands on that (the right) side during the attack in the present case. This headache may, therefore, be distinct from cluster headache, both from a clinical and from an autonomic function point of view.

Sweating patterns in humans: II. Heat-induced forehead sweating and cutaneous temperature in healthy individuals

A comparison of heat-induced forehead sweating and cutaneous temperature patterns has been carried out in 17 healthy individuals (a total of 54 measurements). Only minor asymmetries in facial sweating and temperature were observed. No significant correlation between sweating and cutaneous temperature was found. The reproducibility of the method was excellent.

"Hemicrania continua": a case report

The case of a 42-year-old woman with a 31-year history of continuous unilateral, pulsating headache with occasional exacerbations is described. Complete relief was obtained with 150 mg indomethacin daily.