The immunogenetics of narcolepsy associated with A(H1N1)pdm09 vaccination (Pandemrix) supports a potent gene-environment interaction.

The influenza A(H1N1)pdm09 vaccination campaign from 2009 to 2010 was associated with a sudden increase in the incidence of narcolepsy in several countries. Narcolepsy with cataplexy is strongly associated with the human leukocyte antigen (HLA) class II DQB1*06:02 allele, and protective associations with the DQB1*06:03 allele have been reported. Several non-HLA gene loci are also associated, such as common variants of the T-cell receptor-α (TRA), the purinergic receptor P2RY11, cathepsin H (CTSH) and TNFSF4/OX40L/CD252. In this retrospective multicenter study, we investigated if these predisposing gene loci were also involved in vaccination-associated narcolepsy. We compared HLA- along with single-nucleotide polymorphism genotypes for non-HLA regions between 42 Pandemrix-vaccinated narcolepsy cases and 1990 population-based controls. The class II gene loci associations supported previous findings. Nominal association (P-value<0.05) with TRA as well as suggestive (P-value<0.1) associations with P2RY11 and CTSH were found. These associations suggest a very strong gene-environment interaction, in which the influenza A(H1N1)pdm09 strain or Pandemrix vaccine can act as potent environmental triggers.

Increased ß-haemolytic group A streptococcal M6 serotype and streptodornase B-specific cellular immune responses in Swedish narcolepsy cases.

BACKGROUND: Type 1 narcolepsy is a neurological disorder characterized by excessive daytime sleepiness and cataplexy associated with the HLA allele DQB1*06:02. Genetic predisposition along with external triggering factors may drive autoimmune responses, ultimately leading to the selective loss of hypocretin-positive neurons. OBJECTIVE: The aim of this study was to investigate potential aetiological factors in Swedish cases of postvaccination (Pandemrix) narcolepsy defined by interferon-gamma (IFNγ) production from immune cells in response to molecularly defined targets. METHODS: Cellular reactivity defined by IFNγ production was examined in blood from 38 (HLA-DQB1*06:02(+) ) Pandemrix-vaccinated narcolepsy cases and 76 (23 HLA-DQB1*06:02(+) and 53 HLA-DQB1*06:02(-) ) control subjects, matched for age, sex and exposure, using a variety of different antigens: ß-haemolytic group A streptococcal (GAS) antigens (M5, M6 and streptodornase B), influenza (the pandemic A/H1N1/California/7/09 NYMC X-179A and A/H1N1/California/7/09 NYMC X-181 vaccine antigens, previous Flu-A and -B vaccine targets, A/H1N1/Brisbane/59/2007, A/H1N1/Solomon Islands/3/2006, A/H3N2/Uruguay/716/2007, A/H3N2/Wisconsin/67/2005, A/H5N1/Vietnam/1203/2004 and B/Malaysia/2506/2004), noninfluenza viral targets (CMVpp65, EBNA-1 and EBNA-3) and auto-antigens (hypocretin peptide, Tribbles homolog 2 peptide cocktail and extract from rat hypothalamus tissue). RESULTS: IFN-γ production was significantly increased in whole blood from narcolepsy cases in response to streptococcus serotype M6 (P = 0.0065) and streptodornase B protein (P = 0.0050). T-cell recognition of M6 and streptodornase B was confirmed at the single-cell level by intracellular cytokine (IL-2, IFNγ, tumour necrosis factor-alpha and IL-17) production after stimulation with synthetic M6 or streptodornase B peptides. Significantly, higher (P = 0.02) titres of serum antistreptolysin O were observed in narcolepsy cases, compared to vaccinated controls. CONCLUSION: ß-haemolytic GAS may be involved in triggering autoimmune responses in patients who developed narcolepsy symptoms after vaccination with Pandemrix in Sweden, characterized by a Streptococcus pyogenes M-type-specific IFN-γ cellular immune response.

Risk of hospitalization and death for healthcare workers with COVID-19 in nine European countries, January 2020-January 2021.

This article presents and compares coronavirus disease 2019 attack rates for infection, hospitalization, intensive care unit (ICU) admission and death in healthcare workers (HCWs) and non-HCWs in nine European countries from 31st January 2020 to 13th January 2021. Adjusted attack rate ratios in HCWs (compared with non-HCWs) were 3.0 [95% confidence interval (CI) 2.2-4.0] for infection, 1.8 (95% CI 1.2-2.7) for hospitalization, 1.9 (95% CI 1.1-3.2) for ICU admission and 0.9 (95% CI 0.4-2.0) for death. Among hospitalized cases, the case-fatality ratio was 1.8% in HCWs and 8.2% in non-HCWs. Differences may be due to better/earlier access to treatment, differential underascertainment and the healthy worker effect.

Timing of two versus three doses of quadrivalent HPV vaccine and associated effectiveness against condyloma in Sweden: a nationwide cohort study.

OBJECTIVE: To assess incidence of condyloma after two doses of quadrivalent human papillomavirus (qHPV) vaccine, by time since first vaccine dose, in girls and women initiating vaccination before age 20 years. DESIGN: Register-based nationwide open cohort study. SETTING: Sweden. PARTICIPANTS: Girls and women initiating qHPV vaccination before age 20 years between 2006 and 2012. The study cohort included 264 498 girls, of whom 72 042 had received two doses of qHPV vaccine and 185 456 had received all three doses. MAIN OUTCOME MEASURE: Incidence rate ratios (IRRs) of condyloma estimated by time between first and second doses of qHPV in months (m) and age at vaccination, adjusted for attained age. RESULTS: For girls first vaccinated with two doses before the age of 17 years, the IRR of condyloma for 0-3 months between the first and second doses was 1.96 (95% CI 1.43 to 2.68) as compared with the standard three-dose schedule. The IRRs were 1.27 (95% CI 0.63 to 2.58) and 4.36 (95% CI 2.05 to 9.28) after receipt of two doses with 4-7 months and 8+ months between doses, respectively. For women first vaccinated after the age of 17 years, vaccination with two doses of qHPV vaccine and 0-3 months between doses was associated with an IRR of 2.12 (95% CI 1.62 to 2.77). For an interval of 4-7 months between doses, the IRR did not statistically significantly differ to the standard three-dose schedule (IRR=0.81, 95% CI 0.36 to 1.84). For women with 8+ months between dose 1 and dose 2 the IRR was 3.16 (95% CI 1.40 to 7.14). CONCLUSION: A two-dose schedule for qHPV vaccine with 4-7 months between the first and second doses may be as effective against condyloma in girls and women initiating vaccination under 20 years as a three-dose schedule. Results from this nationwide study support immunogenicity data from clinical trials.

Regenerative electrical activity and arterial contraction in hypertensive rats.

Isolate tail arteries from spontaneously hypertensive rats-stroke prone strain (SHRSP) display oscillatory contractile responses to norepinephrine. These oscillations are not observed in tail arteries from normotensive Wistar-Kyoto rats (WKY). The mechanism underlying these oscillatory contractions was investigated by simultaneous measurement of isometric force development and membrane potential (Em) from tail artery strips in vitro. After equilibration in physiological salt solution containing 1.6 mM calcium (37 degrees C), resting Em was not different between WKY (-52 +/- 1.1 mV) and SHRSP (-52 +/- 0.4 mV). Norepinephrine (3 x 10(-7) M) produced a similar degree of depolarization in tissues from the two strains (WKY = (-42.5 +/- 0.9, SHRSP = -41 +/- 0.8). However, while Em recordings from WKY arteries were quiescent, those from SHRSP displayed bursts of electrical spiking activity that were temporally associated with the rising phase of oscillations in contractile force. The frequency and duration of these bursts of action potentials increased with the concentration of norepinephrine. Action potentials were not observed in calcium-free solution or in presence of nifedipine (3 x 10(-7) M). Releasing the passive stretch on the tissues caused a decrease in the rate of spiking. These studies demonstrate catecholamine-induced regenerative electrical activity in tail arteries from SHRSP that is dependent on extracellular calcium. This activity is unique to tail arteries from this strain.

Functional evidence for increased sodium permeability in aortas from DOCA hypertensive rats.

We studied the role of increased Na+ permeability on the increased responsiveness to ouabain and to K+-free solution in aortas from DOCA hypertensive rats. Helically cut strips from DOCA hypertensive and normotensive control rats were mounted in a muscle bath for recording isometric force. In response to ouabain, aortas from DOCA hypertensive rats were significantly more sensitive and developed a greater maximal force than aortas from control rats. The rate of force development in response to K+-free solution was significantly faster in aortas from DOCA hypertensive rats as compared to those from control rats. Monensin (10(-5)M), a Na+ ionophore, increased the contractile response to ouabain and the rate of force development in response to K+-free solution in both DOCA hypertensive and control aortas. Amiloride (3 X 10(-5) M), a Na+ channel blocker, decreased the contractile response to ouabain and the rate of force development to a K+-free solution in both the DOCA hypertensive and control aortas, but the magnitude of decrease was greater in aortas from DOCA hypertensive rats. Thus, a Na+ ionophore causes the control aortas to perform like those from DOCA hypertensive rats, and a Na+ channel blocker causes aortas from DOCA hypertensive rats to perform like those from control rats. It is concluded that the difference between the two is that the smooth muscle of aortas from DOCA hypertensive rats is more permeable to Na+ than is that from control rats.

Oscillatory contractions in tail arteries from genetically hypertensive rats.

This study characterizes a cellular mechanism for oscillatory contractions induced by norepinephrine in vascular smooth muscle from spontaneously hypertensive stroke prone rats (SHRSP). Helically cut strips of tail arteries from SHRSP and normotensive Wistar-Kyoto rats (WKY) were mounted in a muscle bath for measurement of isometric force generation. Norepinephrine-induced responses of arteries from SHRSP were characterized by fluctuations in contractile activity, whereas those in arteries from WKY remained constant with time. The magnitude of the oscillatory contractile activity (frequency X mean amplitude) varied directly with norepinephrine concentration (5.9 X 10(-9) to 1.8 X 10(-7) M). The oscillatory contractile activity varied inversely with the potassium concentration (3-20 mM) of the buffer solution and directly with the calcium concentration (0.1-5.0 mM) of the buffer solution. The oscillatory activity was converted to maintained contraction by barium (10(-4) M), quinidine (3 X 10(-6) M), sparteine (10(-3) M), D-600 (10(-7) M), and nifedipine (10(-8) M). Tetraethylammonium and 3,4-diaminopyridine, inhibitors of voltage-dependent potassium channels, did not alter the oscillatory contractile activity induced by norepinephrine. These observations suggest that oscillatory contractile activity in tail arteries from SHRSP is caused by an abnormal variation in potassium efflux during stimulation with norepinephrine. The altered potassium efflux appears to be related to calcium entry, which is sensitive to inhibition by channel blockers. This altered membrane property may contribute to changes in vascular sensitivity in hypertension.

Complex RNA processing of TDRKH, a novel gene encoding the putative RNA-binding tudor and KH domains.

The sequence from a human EST (IMAGE:259322) with homology to the nucleotide-sensitive chloride conductance regulator (ICln) was used to screen a human aortic cDNA library. The probe sequence was from a region of the EST lacking homology to ICln, and the goal was to isolate an ICln-like gene. A 2843bp cDNA clone with an open reading frame coding for a 561 amino acid protein was isolated. This clone had no homology to ICln. PROSITE analysis of the putative protein sequence reveals one tudor and two K homology (KH) domains. The gene has therefore been named TDRKH. Both KH and tudor motifs are involved in binding to RNA or single-strand DNA. PCR analysis demonstrated that TDRKH is alternatively spliced in several ways and alternatively polyadenylated at multiple sites. Northern analysis confirmed the presence of messages of multiple lengths with predominant bands at 2.8 and 4.0 kb and also demonstrated that TDRKH is widely expressed in human tissues. Within an intron of TDRKH, there is a region with 90% homology to ICln. This sequence, which is incorporated into the alternatively spliced message represented by IMAGE:259322, contains a 2 bp deletion that disrupts the ICln reading frame and therefore represents an ICln pseudogene. The TDRKH gene was mapped to the Epidermal Differentiation Complex (EDC) at chromosome 1q21 by radiation hybrid mapping and STS content of genomic clones from that region. The EDC contains a large cluster of related genes involved in terminal differentiation of the epidermis. It remains to be determined whether TDRKH has a specific role in epithelial function.

Potassium conductance and oscillatory contractions in tail arteries from genetically hypertensive rats.

Tail arteries isolated from the stroke-prone substrain of the spontaneously hypertensive rat (SHR-SP) exhibit oscillatory contractile responses to norepinephrine. Simultaneous recording of force generation and membrane potential (Em) has previously demonstrated that the contractile phase of these oscillations is associated with bursts of calcium-dependent action potentials. The smooth muscle cells are electrically quiescent during the relaxation phase of the oscillations. The present studies were designed to test the hypothesis that this quiescent period results from the stimulation of a calcium-activated potassium conductance (gKCa) in the cells responsible for triggering the bursting activity. Isolated tail artery strips from SHR-SP and Wistar-Kyoto rats (WKY) were prepared for measurement of isometric force generation or for simultaneous recording of force and Em. The channel-specific toxins apamin (4 x 10(-7) mol/l) and charybdotoxin (4.7 x 10(-8) did not alter the oscillatory pattern of contraction in response to norepinephrine. Oscillations were converted to sustained contraction by barium (10(-4) mmol), quinidine (5.8 x 10(-5) mmol) and elevation of extracellular potassium (20 mmol/l). Em recordings show that both potassium and barium convert bursting activity into tonic firing. Only 20 mmol/k+ caused significant depolarization in addition to that produced by norepinephrine. In contrast, quinidine appears to alter oscillatory behavior by interfering with calcium-spike generation. Norepinephrine-induced electrical activity is diminished in the presence of quinidine. These results suggest that potassium conductance plays an important role in controlling Em, electrical spiking and therefore oscillatory contractile activity in response to norepinephrine in the tail arteries of SHR-SP.(ABSTRACT TRUNCATED AT 250 WORDS)

Contractile responses to ouabain and potassium-free solution in vascular tissue from renal hypertensive rats.

This study characterizes contractions to ouabain and potassium-free solution in isolated vascular segments from two-kidney, one clip (2-K, 1C) hypertensive rats. Aorta, mesenteric artery, and vena cava from hypertensive rats were more sensitive (lower threshold) to ouabain than those from normotensive rats. Contractions of hypertensive vascular segments to potassium-free solution and to ouabain (10(-3) mol/l) were faster than those in normotensive vessels. Monensin potentiated contractions to ouabain and increased the rate of force development to potassium-free solution to a greater extent in normotensive aortae than in hypertensive aortae. Amiloride, low sodium solution, verapamil and calcium-free solution depressed contractions to ouabain and potassium-free solution in both hypertensive and normotensive aortae. These observations demonstrate augmented responsiveness to ouabain and potassium-free solution in hypertensive blood vessels. Interventions which influence transmembrane sodium and calcium movements altered contractions to ouabain and potassium-free solution. The results are consistent with the hypothesis that vascular cells of hypertensive rats have enhanced sodium pump activity.

Calcium and contractile responses to ouabain and potassium-free solution in aortae from spontaneously hypertensive rats.

This study examines the role of calcium in contractions induced by Na+, K+ ATPase inhibition in blood vessels from spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto rats (WKY). Helical strips of aortae from SHR contract more rapidly in response to ouabain or potassium-free conditions than those from WKY rats. Dose-response curves to calcium in SHR aortae treated with 10(-3) mol/l ouabain were shifted to the left of those in WKY. Treatment with 10(-3) mol/l EGTA shifted dose-response curves to calcium in ouabain-treated strips to the left in both strains. The magnitude of the leftward shift induced by EGTA was greater in WKY aortic strips than in those from SHR. Similarly, treatment with EGTA increased the rate of contractile responses to potassium-free solution in WKY aortae to a greater extent than in SHR aortae. Verapamil (10(-6) mol/l) depressed contractions induced by ouabain and potassium-free solution and abolished the differences between SHR and WKY aortae in terms of contraction rate. Calcium-free conditions completely blocked contractions caused by sodium pump inhibition. These results suggest that the difference in responsiveness to sodium pump inhibition in SHR and WKY rats results from an alteration in calcium entry through verapamil-sensitive calcium channels.

Calcium influx and vascular reactivity in systemic hypertension.

Numerous studies have focused on functional vascular changes that characterize the hypertensive state. Recent evidence that suggests that increased vascular reactivity in hypertension is due to changes in the delivery of activator Ca++ through channels in the cell membrane will be reviewed. The primary evidence supporting this hypothesis comes from studies that characterize the effects of Ca++-free solution and calcium channel blockers on contractile properties of isolated vascular smooth muscle. In the present study, experiments were performed to investigate the role of Ca++ influx in vascular contractions produced by interventions that cause membrane depolarization. Isometric tension development in helical strips of carotid arteries from stroke-prone spontaneously hypertensive rats in response to elevated K+ and tetraethylammonium chloride was greater than that in carotid arteries from Wistar-Kyoto normotensive rats. The rate of tension development to K+-free solution in carotid arteries from stroke-prone spontaneously hypertensive rats was faster than in Wistar-Kyoto normotensive rat arteries. Contractile responses to all 3 depolarizing interventions were reduced in arterial strips incubated in Ca++-free solution containing the chelator ethylene glycol bis-(beta-aminoethyl ether) N,N,N',N'-tetraacetic acid and in arterial strips treated with the Ca++ channel blocker verapamil. These results are consistent with the hypothesis that constrictor stimuli that produce membrane depolarization cause an opening of Ca++ channels in the plasma membrane that are sensitive to the organic channel blockers. Further, a change in Ca++ permeability or membrane depolarizing mechanisms contributes to increased contractile responsiveness in carotid arteries of stroke-prone spontaneously hypertensive rats.

Role of Cl(-) channels in alpha-adrenoceptor-mediated vasoconstriction in the anesthetized rat.

In vitro studies have provided evidence that Cl(-) ion currents are important for activation of vascular smooth muscle contraction. The stilbene, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS), disrupts Cl(-) metabolism by blocking Cl(-) channels and by inhibiting Cl(-) bicarbonate exchange. The aims of this study were to: (i) characterize the hemodynamic responses produced by DIDS in pentobarbital anesthetized rats, and (ii) examine vasoconstrictor responses to norepinephrine before and after administration of DIDS. DIDS (2.5-50 micromol/kg, 92.5 micromol/kg total dose, i.v.) produced dose-dependent but transient reductions in mean arterial blood pressure and in hindquarter, renal and mesenteric vascular resistances. Prior to the administration of DIDS, norepinephrine (1. 0-5.0 microgram/kg, i.v.) produced dose-dependent increases in mean arterial pressure, renal resistance and mesenteric resistance, but decreases in hindquarter resistance that were inversely related to dose. After administration of DIDS, the peak pressor responses produced by norepinephrine were either slightly diminished (1.0, 2.5 microgram/kg) or unchanged (5.0 microgram/kg). Peak norepinephrine-induced changes in hindquarter and renal vascular resistance were unaffected by DIDS, while increases in mesenteric resistance were augmented. The total norepinephrine-induced increases in mean arterial pressure (mm Hgxs) were markedly reduced by DIDS. These effects of DIDS on norepinephrine-induced responses were similar, but not identical to those of the voltage-sensitive Ca(2+) channel blocker, nifedipine (500 nmol/kg, i.v.). These findings suggest that DIDS may interfere with norepinephrine-induced depolarization of resistance arteries, thereby preventing activation of voltage-sensitive Ca(2+) channels.

Effect of ramipril on alpha-adrenoceptor-mediated oscillatory contractions in tail artery of hypertensive rats.

Recent studies indicate that norepinephrine-induced contractile oscillations in the tail artery from stroke-prone spontaneously hypertensive rats (SHRSP) may be a vascular phenomenon independent of blood pressure level. The objectives of this study were: (1) to characterize pharmacologically the alpha-adrenoceptor mediating norepinephrine-induced oscillations in tail artery; and (2) to investigate the relationship between blood pressure level, altered by treatments with hydralazine/hydrochlorothiazide or the angiotensin converting enzyme inhibitor ramipril, and the observation of norepinephrine-induced oscillations in tail artery. The alpha 2-adrenoceptor agonists clonidine and guanabenz potently stimulated oscillatory contractions in the tail artery while the alpha 1-adrenoceptor agonists phenylephrine and methoxamine were considerably less potent. Yohimbine, an alpha 2-adrenoceptor antagonist, but not the alpha 1-adrenoceptor antagonist prazosin demonstrated high affinity for the receptor mediating norepinephrine-induced oscillatory contractions. These results support the hypothesis that norepinephrine-induced oscillatory contractions in the tail artery from SHRSP occur primarily through stimulation of alpha 2-adrenoceptors. Ramipril lowered blood pressure in SHRSP after 4 weeks of treatment during 6-10 weeks of life but did not alter the ability of the alpha 2-adrenoceptor agonist clonidine (10(-5) M) to induce contractile oscillations in tail arteries from SHRSP, indicating these oscillations are not a secondary effect of high blood pressure. These studies suggest that norepinephrine-induced oscillations in tail artery from SHRSP may be a vascular trait separate and distinct from blood pressure level and angiotensin II expression early in life.

Cyclosporine augments reactivity of isolated blood vessels.

Administration of cyclosporine (CS) as an immunosuppressive agent in clinical transplantation is associated with multiple side effects including nephrotoxicity and hypertension. These two effects could be related in that the renal changes may be secondary to alterations in organ blood flow. The present studies investigate the ability of CS to augment contractile responsiveness in blood vessels from normotensive rats. Isometric force generation was measured in isolated tail arteries and portal veins. CS (8.3 X 10(-6)M) potentiated tail artery contractile responses to sympathetic nerve stimulation, exogenous norepinephrine, and increases in extracellular potassium concentration. Portal veins undergo spontaneous contractions which are related to the firing of calcium-driven action potentials in the smooth muscle cells. CS significantly increased the frequency of these spontaneous contractile events. These results suggest that components of CS toxicity may involve a direct action on vascular smooth muscle and/or on vascular adrenergic neurotransmission.

Neonatal resuscitation.

Three decades of ongoing research and obstetric and pediatric education have seen neonatal resuscitation develop into a well-organized delivery room procedure. Because neonatal resuscitation does not occur frequently in the Emergency Department, few are well prepared. A designated site in the Emergency Department, trained personnel, appropriate equipment and well defined procedures are necessary. These recommendations for the organization of the resuscitation site, procedures, therapeutic drugs, and required equipment must be individualized to each Emergency Department.

The aftermath of youth suicide--providing postvention services for the school and community.

Suicide is one of the leading causes of death in adolescence. Due to the risk of contagion and maladaptive coping responses in the aftermath of suicide, clinicians have responded by developing postvention services. Based on a considerable amount of experience in this field, target groups of individuals have been identified to receive such assistance. These groups include school administrators, staff, students, families, and community members at large. In addition, it has become clear that the local media response to suicide is of critical importance, and that school administrators and local mental health officials should work effectively with reporters so that news stories do not contribute to suicide contagion.