Language-Independent Acoustic Biomarkers for Quantifying Speech Impairment in Huntington's Disease

PURPOSE

Changes in voice and speech are characteristic symptoms of Huntington's disease (HD). Objective methods for quantifying speech impairment that can be used across languages could facilitate assessment of disease progression and intervention strategies. The aim of this study was to analyze acoustic features to identify language-independent features that could be used to quantify speech dysfunction in English-, Spanish-, and Polish-speaking participants with HD.

METHOD

Ninety participants with HD and 83 control participants performed sustained vowel, syllable repetition, and reading passage tasks recorded with previously validated methods using mobile devices. Language-independent features that differed between HD and controls were identified. Principal component analysis (PCA) and unsupervised clustering were applied to the language-independent features of the HD data set to identify subgroups within the HD data.

RESULTS

Forty-six language-independent acoustic features that were significantly different between control participants and participants with HD were identified. Following dimensionality reduction using PCA, four speech clusters were identified in the HD data set. Unified Huntington's Disease Rating Scale (UHDRS) total motor score, total functional capacity, and composite UHDRS were significantly different for pairwise comparisons of subgroups. The percentage of HD participants with higher dysarthria score and disease stage also increased across clusters.

CONCLUSION

The results support the application of acoustic features to objectively quantify speech impairment and disease severity in HD in multilanguage studies.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25447171.

Functional Characteristics of the Nav1.1 p.Arg1596Cys Mutation Associated with Varying Severity of Epilepsy Phenotypes

Mutations of the SCN1A gene, which encodes the voltage-dependent Na+ channel's α subunit, are associated with diverse epileptic syndromes ranging in severity, even intra-family, from febrile seizures to epileptic encephalopathy. The underlying cause of this variability is unknown, suggesting the involvement of additional factors. The aim of our study was to describe the properties of mutated channels and investigate genetic causes for clinical syndromes' variability in the family of five SCN1A gene p.Arg1596Cys mutation carriers. The analysis of additional genetic factors influencing SCN1A-associated phenotypes was conducted through exome sequencing (WES). To assess the impact of mutations, we used patch clamp analysis of mutated channels expressed in HEK cells and in vivo neural excitability studies (NESs). In cells expressing the mutant channel, sodium currents were reduced. NESs indicated increased excitability of peripheral motor neurons in mutation carriers. WES showed the absence of non-SCA1 pathogenic variants that could be causative of disease in the family. Variants of uncertain significance in three genes, as potential modifiers of the most severe phenotype, were identified. The p.Arg1596Cys substitution inhibits channel function, affecting steady-state inactivation kinetics. Its clinical manifestations involve not only epileptic symptoms but also increased excitability of peripheral motor fibers. The role of Nav1.1 in excitatory neurons cannot be ruled out as a significant factor of the clinical phenotype.

Factors Contributing to Risk of Persistence of Positive and Negative Symptoms in Schizophrenia during Hospitalization

The aim of the study was to evaluate factors that may contribute to the persistence of positive, negative and other psychopathological symptoms of schizophrenia. All patients were treated in general psychiatric wards between January 2006 and December 2017. The initial study sample comprised of the medical reports of 600 patients. The main, specified inclusion criterion for the study was schizophrenia as a discharge diagnosis. Medical reports of 262 patients were excluded from the study due to no neuroimaging scans being available. The symptoms were categorised into three groups: positive, negative, and other psychopathological symptoms. The statistical analysis comprised modalities such as demographic data, clinical symptoms, as well as neuroimaging scans linking them to a potential impact of sustaining the mentioned groups of symptoms during the period of hospitalization. The analysis revealed that statistically significant risk factors of persistence of the three groups of symptoms are the elderly age, the increasing toll of hospitalizations, suicidal attempts in medical history, a family history of alcohol abuse, the presence of positive, negative and other psychopathological symptoms on admission to the hospital, as well as the absence of cavum septi pellucidi (CSP). The study showed that addiction to psychotropic drugs and a family history of schizophrenia were more frequent in patients with persistent CSP.

Vascular Complications After Simultaneous Pancreas and Kidney Transplantation: A Case Report

A 51-year-old patient with type I diabetes and end-stage renal disease was qualified for a simultaneous kidney and pancreas transplant. The procedure was performed in a typical manner: arterial anastomosis to the right common iliac artery, the graft's portal vein with inferior vena cava, and side-to-side duodenal intestinal anastomosis. The kidney was implanted retroperitoneally. Six months after the transplant, the patient reported pain in the right lower abdomen, and imaging examinations revealed arterial anastomosis. Reconstruction of the right common iliac artery was performed with a Gore-Tex prosthesis and the pancreatic artery reanastomosed to the right external iliac artery. After the surgery, the function of the transplanted pancreas deteriorated, the level of C-peptide was decreased, and the patient required low doses of insulin. After another 8 months, the imaging studies revealed an aneurysm located in the bifurcation of the aorta up to the anastomosis of the pancreatic graft artery with the iliac artery. The patient was qualified for the implantation of an endovascular of 2 prosthesis, which improved the graft's function. After another 2 months, the presence of an aneurysm at the endovascular prosthesis was found again. The patient was requalified for endovascular prosthesis implantation. Currently, there is no aneurysm but the function of the pancreas graft is impaired, though the kidney graft function is good. Patients after simultaneous kidney and pancreas transplant are a group of patients with an increased risk of vascular complications. Treatment should take place in a multidisciplinary center.

Impact of COVID-19 on pancreatic cancer surgery: A high-volume Polish center experience

BACKGROUND

A total of 148 surgeries were performed in our center on patients with pancreatic cancer in 2020. In 2019, 263 such procedures were performed (77.7% more) in this facility.

OBJECTIVES

To analyze the impact of coronavirus disease 2019 (COVID-19) on pancreatic cancer surgery type, number and outcome in our center.

MATERIAL AND METHODS

Retrospective data analysis of medical documentation in a hospital database from January 2019 till December 2020.

RESULTS

In 2020, we observed an increase of tumors localized in the tail of the pancreas (P) - 29 cases (19.9%) in 2020 compared to 26 cases (9.9%) in 2019 (p = 0.005). In 2020, our patients presented with much greater advancement of the disease illustrated by the increased tumor size (median 3.5 cm in 2020 compared to 3.0 cm in 2019), although it did not reach statistical significance (p = 0.073). In 2020, we performed more palliative procedures, e.g., bypassing anastomoses (17 (11.6%) in 2020 compared to 8 (3%) in 2019 (p < 0.001)), more open biopsies of P (21 (14.4%) in 2020 compared to 21 (7.9%) in 2019 (p = 0.041)), and more percutaneous biopsies of P (7 (4.8%) in 2020 and 0 in 2019 (p = 0.001)). We observed a significant decrease in the number of Whipple procedures (53 (36.3%) in 2020 and 125 (47.5%) in 2019 (p = 0.037)). The most common histopathological finding was adenocarcinoma of the P, accounting for 50% in 2020 and almost 52% of all tumor cases in 2019. In a group of 148 patients operated on due to a P tumor during the COVID-19 pandemic, only 6 patients died, which resulted in a mortality rate of 4.1% compared to 13.4% mortality rate in 2019 (34 deaths/263 patients; p = 0.005). We observed less leakage of gastrointestinal anastomosis (0/148 in 2020 and 10/263 in 2019 (p = 0.038)).

CONCLUSIONS

Particular attention should be paid to patients with an aggressive type of cancer who have completed neoadjuvant therapy, as they are unable to undergo other therapeutic options. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive cancer patients should be postponed until recovery. Relatively few postoperative complications and low all-cause mortality are the result of a more careful selection of oncological patients before the admission to the surgical ward, as well as a ompliance with the principles of planning the procedure and organization of the operating theater during the COVID-19 pandemic.

Pancreas Allograft Thrombosis as a Post-COVID-19 Complication in a Diabetic Patient After Pancreas Transplantation

Arterial and venous thrombosis of pancreatic allografts is a rare complication in the late post-transplantation period. In addition to traditional thrombosis risk factors, SARS-CoV-2 infection predisposes patients to thrombotic diseases in both arterial and venous vessels. Transplant patients with a history of COVID-19 should be carefully monitored for arterial embolism and graft vein thrombosis. Early detection of this complication in patients after transplantation allows a chance to save the organ. Thromboprophylaxis with low molecular weight heparin is of great importance.

Neuroma (schwannoma). A rare pancreatic tumor

INTRODUCTION

Neuroma (Schwannoma in Latin) is an encapsulated, mesenchymal tumor arising from Schwann cells surrounded by nerves. Hence it can be located in any area in the body with passing peripheral nerves. The most common location is the head, neck, and extremities. The tumor arising from Schwannoma cells was first described by Stout and Carson in 1935. Pancreatic schwannomas are extremely rare tumors. Until 2017, in English literature 68 cases have been described. Surgical treatment is the most common way of treating pancreatic schwannomas, and postoperative prognoses are good.

CASE REPORT

A 63-year-old patient was admitted to the Clinical Department of Gastroenterological Surgery and Transplantation of the Central Clinical Hospital at the Ministry of Interior and Administration in Warsaw due to pancreatic head cancer. Needle biopsy-both ultrasound-guided and CT-guided as well as open biopsy for lesions in the pancreas did not show tumor cells in any of the collected samples. Abdominal CT in a projection of the uncinate process of the pancreas revealed an oval lesion highly suspected of neoplastic process. Next, diagnostics was extended by abdominal MRI which revealed a retroperitoneal tumorous thick-walled cystic mass filled with fluid. The patient was qualified for surgical treatment. Pancreaticoduodenectomy (Whipple Procedure) was done on August 22, 2017. Material sent for histopathological examination revealed Schwannoma capitis pancreatis. In surgical practice, pancreatic schwannoma occurs extremely rare, but in centers which conduct large numbers of surgical procedures in the pancreas, a case like this may occur.

Synthesis of Highly Oxygenated Bicyclic Carbasugars. Remarkable Difference in the Reactivity of the d-gluco and d-xylo- Derived Trienes

2,3,4-Tri-O-benzyl-D-xylopyranose was used as a starting material in the preparation of the corresponding triene, which underwent smooth cyclization to a polyhydroxylated hydrindane, as a single diastereoisomer. The analogous triene prepared from D-glucose did not undergo any cyclization even under high pressure.

Hybrid simulation of pediatric gynecologic examination: a mix-methods study of learners' attitudes and factors affecting learning

BACKGROUND

Children and adolescents with reproductive health issues may require immediate or emergency care, however in many countries availability of the pediatric and adolescent gynecology (PAG) service is low. That being said, teaching PAG examination to OBGYN, pediatrics and emergency medicine residents seems reasonable, and cannot be underestimated. In order to provide residents with opportunity to learn PAG examination, a high-fidelity hybrid simulation workshop was implemented in our institution.

METHODS

The study aimed to investigate learners' attitudes towards the high-fidelity simulation (HFS) hybrid model as compared with task trainer-SP (simulated patient)-voice model in the HFS environment and the factors connected to learners' attitudes towards the hybrid model that could influence learning in high-fidelity simulation (HFS). The concept of attitude was used as the theoretical framework and the mixed method approach to study design was utilized with simultaneous collection of quantitative (original questionnaires) and qualitative data (semi-structured interviews).

RESULTS

Residents valued the HFS hybrid model higher over task trainer-SP-voice model in regards to all three attitude components: cognitive (95%), affective (87.5%) and behavioral (83.7%). Analysis of qualitative data revealed six themes important to learners and informing learning of PAG examination in HFS. Further analysis of the themes allowed to develop a conceptual model, in which six factors connected to attitude components influenced learning. These factors were: task difficulty, attention, emotional realism of the simulation, patient's emotions, physical realism of the simulation, and technical issues.

CONCLUSIONS

Participants of our study appreciated learning experience with the HFS hybrid model more, based on attitude questionnaire. Moreover, findings revealed that multiple, various factors connected to attitude may influence learning of PAG examination in HFS with hybrid model, and we propose a conceptual model illustrating relationships between those factors.

A case of acute pancreatitis - does step-up protocol always indicated?

Acute pancreatitis (AP) is still one of the most frequent cause of hospitalization. Grading severity of AP due to revised Atlanta classification differentiate: mild, moderately severe and severe AP. Mortality ranges from occasional tomild,8% in moderate, 36%-59% in severe AP.

A CASE REPORT

59-year-old man was hospitalized due to severe acute pancreatitis. Biliary duct obstruction was determined as a reason of AP and intensive treatment was started. The CT scan showed infected post-inflammatory pancreatic cyst. For this reason, endoscopic drainage of the pancreatic cyst to the stomach was performed first and then Jurasz operation. Severe postoperative course required treatment in the Intensive Care Unit (ICU). During the next hospitalization due to the patient's condition deterioration, endoscopic cyst drainage was performed again. Because of ineffectiveness of the performed treatment, the patient was reoperated. Post-operative multi-organ failure, lack of response to the intensive therapy and cachexia because of long-lasting illness, lead into patient's death.

CONCLUSIONS

This case demonstrates problem with severe complications of AP which despite of multidisciplinary treatment combining endoscopy, surgery and pharmacology can finally lead to death.

Endovascular Treatment of Pseudoaneurysm After Simultaneous Pancreas-Kidney Transplant: A Case Report

Pseudoaneurysm is a rare vascular complication in pancreas transplantation that can lead into life-threatening situations. A 44-year-old male patient after simultaneous pancreas-kidney transplant was admitted to the hospital for routine tests 3 months after surgery. A computed tomography scan and ultrasound examination were done, and a diagnosis of pseudoaneurysm was made. The patient was qualified for endovascular treatment. The pseudoaneurysm was closed using coils, and kidney and pancreas grafts stayed in proper condition. Endovascular interventions in patients after pancreas transplantation are safe and preferable in managing postoperative complications.

Alterations in transcranial sonography among Huntington's disease patients with psychiatric symptoms

Transcranial sonography (TCS) is a diagnostic tool in mood and movement disorders. Alterations within the raphe mesencephalic nucleus in the brain have been reported not only in patients with major depression but in patients with depressive symptoms accompanying several neurodegenerative disorders. The aim of the study was to assess the echogenicity of the nucleus raphe and other basal ganglia in patients with Huntington’s disease (HD). TCS was performed in 127 HD patients participating in observational studies (Registry/Enroll-HD) in the Institute of Psychiatry and Neurology (Warsaw, Poland). Raphe hypoechogenicity was found in 78% of HD patients with current symptoms of depression (according to DSM-IV criteria), 57% of patients with a previous history of depression, and 56.8% patients who lacked signs or history of depression. Patients with hypoechogenic raphe reported significantly higher depression as measured on the BDI (15.6 ± 1.7) as compared to patients with normal echogenicity (9.5 ± 1.2), (p = 0.023). The diameter of the third ventricle was negatively correlated with Mini-Mental State Examination (MMSE) (rho − 0.37) and total functional capacity (TFC) scores (rho − 0.26). Hyperechogenic substantia nigra was visualized in 66,4% patients with HD and the degree of hyperechogenicity was correlated with the total motor score (TMS) (rho − 0.38). Changes in echogenicity of the basal ganglia are related to both depressive and motor symptoms among patients with HD.

Prevalence of Non-psychiatric Comorbidities in Pre-symptomatic and Symptomatic Huntington's Disease Gene Carriers in Poland

Huntington's disease (HD) is monogenic neurodegenerative disorder caused by CAG expansions within the Huntingtin gene (Htt); it has a prevalence of 1 in 10,000 worldwide and is invariably fatal. Typically, healthy individuals have fewer than 35 CAG repeats, while the CAG expansions range from 36 to ~200 in HD patients. The hallmark of HD is neurodegeneration, especially in the striatal nuclei, basal ganglia and cerebral cortex, leading to neurological symptoms that involve motor, cognitive, and psychiatric events. However, HD is a complex disorder that may also affect peripheral organs, so it is possible that HD patients could be affected by comorbidities. Hence, we investigated the prevalence of comorbid conditions in HD patients (pre-symptomatic and symptomatic groups) and compared the frequency of those conditions to a control group. Our groups represent 65% of HD gene carriers registered in Poland. We identified 8 clusters of comorbid conditions in both HD groups, namely: musculoskeletal, allergies, cardiovascular, neurological, gastrointestinal, thyroid, psychiatric, and ophthalmologic. We found that HD patients have a significantly higher percentage of co-existing conditions in comparison to the control group. Among the 8 clusters of diseases, musculoskeletal, psychiatric, and cardiovascular events were significantly more frequent in both pre- and symptomatic HD patients, while neurological and gastrointestinal clusters showed significantly higher occurrence in the HD symptomatic group. A greater recognition of comorbidity in HD might help to better understand health outcomes and improve clinical management.

Autoimmune meningitis and encephalitis in adult-onset still disease - Case report

INTRODUCTION

Adult-onset Still disease (AOSD) is a rare systemic inflammatory disease of unknown cause. Its symptoms usually include persistent fever, fugitive salmon-colored rash, arthritis, sore throat (not specific), but it may also lead to internal organs' involvement, which presents with enlargement of the liver and spleen, swollen lymph nodes, carditis or pleuritis - potentially life-threatening complications. In rare cases, AOSD can cause aseptic meningitis or/and encephalitis.

CASE PRESENTATION

We report a case of 31-year-old male patient, who was referred to neurological department for extending diagnostics of frontal lobes lesions with involvement of adjacent meninges. Abnormalities have been revealed in brain MRI, which was performed due to persistent headaches, visual disturbances, fever, fatigue and cognitive decline. Wide differential diagnosis was performed including laboratory findings, contrast enhanced MRI, MR spectroscopy, flow cytometry and finally brain biopsy to exclude neoplastic or infectious origin. Final diagnosis of autoimmune meningoencephalitis in adult-onset Still disease has been made.

CONCLUSION

Adult-onset Still disease is a rare cause of inflammatory changes in central nervous system, which if diagnosed, may be treated successfully with steroids (commonly available agent), intravenous immunoglobulins or more specific immunomodulating regiments.

An unusual presentation of Listeria monocytogenes rhombencephalitis

We describe a case of 52-year-old woman with a medical history of Crohn's disease presented abrupt fever, asymmetrical multiple cranial nerve palsies and focal neurological symptoms localized to the brainstem. The patient was initially diagnosed with ischaemic stroke, because of acute clinical course and results of neuroimaging. Cerebrospinal fluid analysis revealed mild infection with negative Gram staining and culture. Final diagnosis of Listeria monocytogenes brainstem infection (rhombencephalitis) was set up on the basis of further clinical course and positive blood cultures. Listerial rhombencephalitis should be kept in mind in immunocompromised adult patients who develop fever, asymmetrical multiple cranial nerve palsies and focal neurological symptoms localized to the brainstem even without typical neuroimaging, cerebrospinal fluid findings and negative cultures. Early diagnosis and adequate antibiotic treatment is of crucial importance.

Midbrain and bilateral paramedian thalamic stroke due to artery of Percheron occlusion

INTRODUCTION

Bilateral thalamic strokes are rare manifestations of posterior circulation infarcts. Usually the etiology is cardioembolic or small vessel disease combined with individual anatomical predisposition. The symptoms include a variety of neurological deficits depending on thalamic structure involvement, such as paresthesias or numbness, hemiparesis with increased reflexes and Babinski sign, third cranial nerve palsy, speech and cognition disturbance, memory impairment and stupor. Neuroimaging usually reveals ischemic loci in adequate thalamic nuclei.

CASE PRESENTATION

We report a case of 61-year-old man, active smoker (25/per day, 50 pack-years) with untreated hypertension who presented at admission consciousness impairment (Glasgow Coma Scale score 9 points), left pupil dilatation without reaction to light, left eye deviation downwards and outwards, vertical gaze paralysis and left-sided hemiplegia. Initial brain computed tomography (CT) was normal. Brain magnetic resonance with diffusion weighted imaging and fluid attenuation inversion recovery sequences (MR DWI/FLAIR) performed on admission showed ischemic changes in bilateral thalami, which were confirmed in routine MRI. Thrombosis of basilar artery and cerebral venous was excluded in CT angiography. Further diagnostic assessment revealed hyperlipidemia, paroxysmal atrial fibrillation and renal cancer with hepatic metastases.

CONCLUSION

Bilateral thalamic stroke due to artery of Percheron occlusion is a rare presentation of stroke, which can be overlooked in routine CT scan. If diagnosed, it requires further evaluation for stroke risk factors, especially cardiovascular disorders associated with increased embolic risk.

Correlations between cerebellar and brain volumes, cognitive impairments, ApoE levels, and APOE genotypes in patients with AD and MCI

Due to the increasing incidence of Alzheimer's disease (AD), many studies have aimed to improve its diagnosis. Particular attention has been focused on measuring volumes of brain structures. Only few studies have investigated whether the cerebellar volume changes with the stage of dementia. It is controversial whether the serum apolipoprotein E (ApoE) level is an appropriate AD marker. This study was designed to clarify the significance of both cerebellar volume measurements and ApoE level measurements as markers of neurodegenerative changes. This study included 55 subjects with AD, 30 subjects with mild cognitive impairments (MCI), and a control group with 30 subjects. We measured the brain, cerebellum, and brain stem volumes with magnetic resonance imaging (MRI). We determined serum ApoE levels, APOE genotypes, and neuropsychological test scores. In the control group, we found that ApoE levels were significantly higher for subjects with the APOE 2/3 genotype than those with the 4/4 genotype. This finding may indicate that ApoE plays a protective role against AD development in subjects with the APOE 2/3 genotype. ApoE levels were not significantly different in patients with AD and MCI. No correlations were found between serum ApoE levels and Mini-Mental State Examination (MMSE) scores or the volumes of brain structures. This study could not confirm the appropriateness of the cerebellum volume as an early AD marker. Correlations were found between cerebellar volume, brain volume, and the MMSE scores.

Effect of cyclic adenosine monophosphate on the G protein-dependent inward rectifier K(+)-like channel current in medial prefrontal cortex pyramidal neurons

Cyclic adenosine monophosphate (cAMP) levels in medial prefrontal cortex (mPFC) pyramidal neurons are altered in neuropsychiatric disorders. cAMP is a component of the transduction pathways involved in the control of ionic channels by metabotropic receptors. The purpose of this study was to determine whether cAMP modifies the activity of the G protein-dependent inward rectifier K(+) (GIRK)-like channel current in the mPFC pyramidal neurons of 3-week-old rats. Channel currents were recorded in a patch clamp cell-attached configuration. Membrane-permeable adenylyl cyclase activator forskolin (10 μM) and membrane-permeable protein kinase A (PKA) activator 8-Br-cAMP (100 μM) were found to significantly decrease the open probability (Po) of the GIRK-like channels. Conversely, selective protein kinase A inhibitors: H-89 (10 μM) and KT5720 (0.5 μM) increased the open probability of the GIRK-like channels. Also, the effect of forskolin was tested after preincubation of the neurons with the PKA inhibitor (KT5720). The application of forskolin, despite PKA inhibition, significantly decreased the Po of the GIRK-like channels. This finding suggested that GIRK-like channel current activity might also be inhibited by cAMP in a PKA-independent manner. A compound, 8CPT-2Me-cAMP (10 μM), which is a specific activator of the Epac protein, which in turn is another intracellular target of cAMP, was also found to inhibit GIRK-like channel activity. We conclude that the constitutive activity of neuronal GIRK-like channel currents is inhibited by cAMP. We suggest that PKA and Epac might be components of the transduction pathway between cAMP and the GIRK channels.

[Predictors of smoking cessation after stroke]

Cigarette smoking is a major modifiable risk factor for stroke. Smoking dose dependently increases the risk of stroke, especially in patients below 75 years of age. Although smoking cessation is considered as one of the most effective methods of secondary stroke prevention, little is known about nicotine dependence and predictors of smoking cessation after stroke. Identification of such predictors could facilitate the development of anti-smoking interventions in post-stroke patients. Results of previous studies showed that smoking cessation is determined by the interplay of multiple factors, including sociodemographic (gender, age, race, living conditions, employment), clinical (functional status), psychobiological (nicotine dependence, depressed mood) and environmental (smoking household members) factors. Limitations of most studies were relatively small sample sizes and lack of verification of smoking status with a biochemical marker (e.g. expired CO). The aim of this article is to summarize current knowledge about predictors of smoking cessation after stroke.

[Cardiac, respiratory and sleep disorders in patients with myotonic dystrophy]

Myotonic dystrophy (MD) is a genetically determined disease with autosomal dominant mode of inheritance. Relatively recently, MD has been divided into two sub-types (MD1 and MD2). Clinical symptoms of MD1 result from the expansion of a (CTG)n trinucleotide of the gene coding for serine/threonine protein kinase and clinical symptoms in MD2 are associated with the expansion of (CCTG)n in I intron of the zinc-finger protein 9 (ZNF9). Myotonic dystrophies MD1 and MD2 are multisystem diseases with numerous symptoms and high interfamily variability, resulting from the fact that different organs are affected. Until now the mechanisms that lead to the damage of the central and peripheral nervous systems, heart muscle and endocrine system have not been fully understood. Symptoms that are characteristic of MD1 and MD2 are myotonic symptom, muscular weakness and muscular atrophy. In MD2, muscular weakness and muscular atrophy are expressed more significantly in proximal segments, which is a differentiating factor for patients with MD1 who have muscular weakness and muscular atrophy in distal segments. Apart from myotonia and symptoms of skeletal muscle damage, the disease affects smooth muscles, heart muscle and the central nervous system, causing cataract, endocrine disorders, cognitive dysfunctions, intellectual and personality disturbances as well as sleep disordered breathing with nocturnal hypoventilation, obstructive, central and mixed apneas and hypopneas. The symptoms of sleep disordered breathing is fatigue, reduced cognitive performance and excessive daytime sleepiness. The pathophysiology of the breathing disorders includes weakness of the respiratory muscles and disorder of the respiratory drive. Of some interest are the works in which authors evaluated the incidence and character of abnormalities in the peripheral and central nervous systems. It has been shown that the number of CTG-repeats in the same person with MD1 is not stable over time and may increase, which leads to disease progression and new clinical symptoms. Cardiologic disorders associated with myotonic dystrophy are common and are part of the clinical picture of the disease. The dominant pathology are conduction disturbances and cardiac arrhythmias. It is estimated that 40 to 80% of patients with MD1 have abnormalities in ECG, and rapid supra-ventricular and ventricular cardiac arrhythmias are the second common cause of death in patients with MD1. Unfortunately, most of these pathologies are asymptomatic until life-threatening conduction blocks and/or supra-ventricular tachyarrhythmias occur. Sometimes, prodromal symptoms such as collapsing, fainting or feeling of palpitation occur and they should always draw attention of the treating doctor of a patient with muscular dystrophy. This paper is aimed at characterizing some common cardiologic and sleep related respiratory disorders of patients with myotonic dystrophy which if not recognized in good time may lead to sudden death.

Opioid mu receptor activation inhibits sodium currents in prefrontal cortical neurons via a protein kinase A- and C-dependent mechanism

Opioid transmission in the medial prefrontal cortex is involved in mood regulation and is altered by drug dependency. However, the mechanism by which ionic channels in cortical neurons are controlled by mu opioid receptors has not been elucidated. In this study, the effect of mu opioid receptor activation on voltage-dependent Na(+) currents was assessed in medial prefrontal cortical neurons. In 66 out of 98 nonpyramidal neurons, the application of 1 microM of DAMGO ([D-Ala(2), N-Me-Phe(4), Gly(5)-OL]-enkephalin), a specific mu receptor agonist, caused a decrease in the Na(+) current amplitude to approximately 79% of that observed in controls (half blocking concentration = 0.094 microM). Moreover, DAMGO decreased the maximum current activation rate, prolonged its time-dependent inactivation, and shifted the half inactivation voltage from -63.4 mV to -71.5 mV. DAMGO prolonged the time constant of recovery from inactivation from 5.4 ms to 7.4 ms. The DAMGO-evoked inhibition of Na(+) current was attenuated when GDP-beta-S (0.4 mM, Guanosine 5-[beta-thio]diphosphate trilithium salt) was included in the intracellular solution. Inhibitors of kinase A and C greatly attenuated the DAMGO-induced inhibition, while adenylyl cyclase and kinase C activators mirrored the DAMGO inhibitory effect. Na(+) currents in pyramidal neurons were insensitive to DAMGO. We conclude that the activation of mu opioid receptors inhibits the voltage-dependent Na(+) currents expressed in nonpyramidal neurons of the medial prefrontal cortex, and that kinases A and C are involved in this inhibitory pathway.

Effects of ATP and GTP on voltage-gated K+ currents in glandular and muscular sympathetic neurons

This study assesses the effects of ATP and GTP on the kinetic properties of voltage-gated K+ currents in anatomically identified postganglionic sympathetic neurons innervating the submandibular gland and the masseter muscle in rats. Three types of K+ currents were isolated: the I(Af) steady-state inactivating at more hyperpolarized potentials, I(As) steady-state inactivating at less hyperpolarized potentials than I(Af) and the I(K) current independent of membrane potential. The kinetic properties of these currents were tested in neurons with ATP (4 mM) and GTP (0.5 mM) or without ATP and GTP in the intracellular solution. In glandular and muscular neurons in the absence of ATP and GTP in the intracellular solution, the current density of I(Af) was significantly larger (142 pA/pF and 166 pA/pF, respectively) comparing to cells with ATP and GTP (96 pA/pF and 100 pA/pF, respectively). The I(As) was larger only in glandular neurons (52 pA/pF vs. 37 pA/pF).Conversely, I(K) current density was smaller in glandular and muscular neurons without ATP and GTP (17 pA/pF and 31 pA/pF, respectively) comparing to cells with ATP and GTP (57 pA/pF and 58 pA/pF, respectively). In glandular (15.5 nA/ms vs. 6.9 nA/ms) and muscular (10.9 nA/ms vs. 7.5 nA/ms) neurons, the I(Af) activated faster in the absence of ATP and GTP. Half inactivation voltage of I(Af) in glandular (-110.0 mV vs. -119.7 mV) and muscular (-108.4 vs. -117.3 mV) neurons was shifted towards depolarization in the absence of ATP and GTP. We suggest that the kinetic properties of K+ currents in glandular and muscular sympathetic neurons change markedly in the absence of ATP and GTP in the cytoplasm. Effectiveness of steady-state inactivated currents (I(Af) and I(AS)) increased, while effectiveness of steady-state noninactivated currents decreased in the absence of ATP and GTP. The effects were more pronounced in glandular than in muscular neurons.

Voltage-dependent K+ currents in rat cardiac dorsal root ganglion neurons

We have assessed the expression and kinetics of voltage-gated K(+) currents in cardiac dorsal root ganglion (DRG) neurons in rats. The neurons were labelled by prior injection of a fluorescent tracer into the pericardial sack. Ninety-nine neurons were labelled: 24% small (diameter<30 microm), 66% medium-sized (diameter 30 microm>.48 microm) and 10% large (>48 microm) neurons. Current recordings were performed in small and medium-sized neurons. The kinetic and pharmacological properties of K(+) currents recorded in these two groups of neurons were identical and the results obtained from these neurons were pooled. Three types of K(+) currents were identified:a) I(As), slowly activating and slowly time-dependently inactivating current, with V(1/2) of activation -18 mV and current density at +30 mV equal to 164 pA/pF, V(1/2) of inactivation at -84 mV. b) I(Af) current, fast activating and fast time-dependently inactivating current, with V(1/2) of activation at two mV and current density at +30 mV equal to 180 pA/pF, V(1/2) of inactivation at -26 mV. At resting membrane potential I(As) was inactivated, whilst I(Af), available for activation. The I(As) currents recovered faster from inactivation than I(Af) current. 4-Aminopiridyne (4-AP) (10 mM) and tetraethylammonium (TEA) (100 mM) produced 98% and 92% reductions of I(Af) current, respectively and 27% and 66% of I(As) current, respectively. c) The I(K) current that did not inactivate over time. Its V(1/2) of activation was -11 mV and its current density equaled 67 pA/pF. This current was inhibited by 95% (100 mM) TEA, whilst 4-AP (10 mM) produced its 23% reduction. All three K(+) current components (I(As), I(Af) and I(K)) were present in every small and medium-sized cardiac DRG neuron. We suggest that at hyperpolarized membrane potentials the fast reactivating I(As) current limits the action potential firing rate of cardiac DRG neurons. At depolarised membrane potentials the I(Af) K(+) current, the reactivation of which is very slow, does not oppose the firing rate of cardiac DRG neurons.

Voltage-dependent Ca2+ currents in rat cardiac dorsal root ganglion neurons

This study presents the kinetic and pharmacological properties of voltage-gated Ca(2+) currents in anatomically defined cardiac dorsal root ganglion (DRG) neurons in rats. The neurons were labelled by prior injection of fluorescent tracer Fast Blue into the pericardial sack. There were three distinct groups of neurons with respect to cell size: small (27% of total; cell capacitance <30 pF), medium (65% of total; capacitance 30-80 pF) and large neurons (8% of total; capacitance >80 pF). The properties of Ca(2+) currents were tested in small and medium-sized neurons. In large neurons currents could not be adequately controlled and were not analysed. Ca(2+) currents did not completely inactivate during 100 ms depolarising voltage steps. The activation thresholds in small (-36.9+/-1.3 mV) and medium (-39.0+/-1.3 mV) size neurons were similar. Current densities were 105.8 pA/pF in small and 97.4 pA/pF in large neurons and also did not differ. The kinetic properties of activation and inactivation did not differ between small and medium-sized cardiac DRG neurons. At membrane potentials between -50 and -60 mV (the expected resting membrane potential in these neurons) 55 to 70% of Ca(2+) currents in small and medium-sized neurons were available for activation. Both, small and medium-sized neurons expressed similar proportions of L (7.5%), N (25%) and P/Q (36%) type Ca(2+) currents. We conclude that small and medium-sized cardiac DRG neurons are homogeneous with respect to the expression and properties of voltage-gated Ca(2+) currents. Voltage-gated Ca(2+) currents probably play an important role in action potential generation in cardiac DRG neurons due to their availability for activation at resting membrane potential, their high density and voltage threshold close to the threshold for voltage-gated Na(+) currents.

[Nociceptive neurons]

Pain is generated by activation of specific dorsal root ganglion (DRG) neurons termed the nociceptive neurons. The nociceptive DRG neurons express 3 categories of ionic channels a. channels gated by pain stimuli, b. channels responsible for the transmission of information from sensory receptors to the spinal cord, c. channels responsible for the release of neurotransmitters in the spinal cord. There is evidence that kinetic properties, molecular structure and functional significance of the ionic channels expressed in nociceptive DRG neurons are different compared to the other types of DRG neurons. The ionic channels are strictly controlled by receptors for neurotransmitters expressed in the plasma membrane of nociceptive DRG neurons.

Expression and kinetic properties of Na(+) currents in rat cardiac dorsal root ganglion neurons

The expression and properties of voltage-gated Na(+) currents in cardiac dorsal root ganglion (DRG) neurons were assessed in this study. Cardiac DRG neurons were labelled by injecting the Fast Blue fluorescent tracer into the pericardium. Recordings were performed from 138 cells. Voltage-dependent Na(+) currents were found in 115 neurons. There were 109 neurons in which both tetrodotoxin-sensitive (TTX-S, blocked by 1 microM of TTX) and tetrodotoxin-resistant (TTX-R, insensitive to 1 microM of TTX) Na(+) currents were present. Five cells expressed TTX-R current only and one cell only the TTX-S current. The kinetic properties of Na(+) currents and action potential waveform parameters were measured in neurons with cell membrane capacitance ranging from 15 to 75 pF. The densities of TTX-R (110.0 pA/pF) and TTX-S (126.1 pA/pF) currents were not significantly different. Current threshold was significantly higher for TTX-R (-34 mV) than for TTX-S (-40.4 mV) currents. V(1/2) of activation for TTX-S current (-19.6 mV) was significantly more negative than for TTX-R current (-9.2 mV), but k factors did not differ significantly. V(1/2) and the k constant for inactivation for TTX-S currents were -35.6 and -5.7 mV, respectively. These values were significantly lower than those recorded for TTX-R current for which V(1/2) and k were -62.3 and -7.7 mV, respectively. The action potential threshold was lower, the 10-90% rise time and potential width were shorter before than after the application of TTX. Based on this we drew the conclusion that action potential recorded before adding tetrodotoxin was mainly TTX-S current dependent, while the action potential recorded after the application of toxin was TTX-R current dependent. We also found 23 cells with mean membrane capacitance ranging from 12 to 35 pF (the smallest labelled DRG cells found in this study) that did not express the Na(+) current. The function of these cells is unclear. We conclude that the overwhelming majority of cardiac dorsal root ganglion neurons in which voltage-dependent Na(+) currents were present, exhibited both TTX-S and TTX-R Na(+) currents with remarkably similar expression and kinetic properties.

Pharmacokinetic studies of amoxicillin, potassium clavulanate and their combination

Pharmacokinetic parameters after oral administration of 500 mg amoxicillin, 125 mg potassium clavulanate and 625 mg of their combination (augmentin) were determined in a randomized crossover study in ten healthy volunteers. The absolute bioavailability of amoxicillin (AUCoral/AUCi.v.) was 0.70 +/- 0.12. The mean maximum serum concentration of amoxicillin was 6.5 +/- 1.6 mg/l after administration alone and 6.5 +/- 1.4 mg/l after administration in combination. The respective values for potassium clavulanate were 3.4 +/- 1.4 mg/l and 2.8 +/- 1.1 mg/l. With both substances there was no significant difference between the pharmacokinetic parameters after administration alone and in combination. The AUC for amoxicillin was 19.5 +/- 5.4 h x mg/l after administration alone and 23.2 +/- 10.6 h x mg/l after administration in combination. The respective value for potassium clavulanate were 7.8 +/- 3.2 h x mg/l and 7.3 +/- 2.0 h x mg/l.