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1.
J Neurol Sci ; 457: 122880, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38219384

RESUMEN

INTRODUCTION: Stroke in people living with HIV (PLWH) has been described to occur soon after the initiation of antiretroviral therapy (ART) possibly related to the Immune Reconstitution Inflammatory Syndrome (IRIS). We sought to investigate whether there was a temporal association between stroke and recent ART initiation in the absence of opportunistic infections (OIs), and to identify risk factors for this. METHODS: This cross-sectional study recruited PLWH with new-onset stroke at a hospital in Johannesburg, South Africa, from 2014 to 2017, excluding all patients with OIs. Patients were assessed for ART duration, CD4 count, HIV viral load, inflammatory markers and cardiovascular risk factors. RESULTS: 77 PLWH were recruited, of which 35 were on ART at the time of stroke. Of the patients with confirmed ART duration (n = 28), 9 (32.1%) had a stroke within the first 6 months of starting ART (crude incidence rate of 0.73 cases per patient year). In the period beyond 6 months, 19 strokes occurred (crude incidence rate of 0.21 cases per patient year), translating to a 3.5 times greater risk in the first 6 months (p = 0.0002). There were no clearly identified risk factors when comparing those who had strokes in the first 6 months to those after 6 months and ART-naïve patients. CONCLUSION: Almost a third of strokes in PLWH may be related to IRIS, with a crude incidence rate 3.5 times higher in the first 6 months following ART-initiation compared to beyond 6 months. This appears to be independent of OIs. Risk factors are unclear.


Asunto(s)
Infecciones por VIH , Síndrome Inflamatorio de Reconstitución Inmune , Infecciones Oportunistas , Accidente Cerebrovascular , Humanos , Síndrome Inflamatorio de Reconstitución Inmune/epidemiología , Síndrome Inflamatorio de Reconstitución Inmune/etiología , Estudios Transversales , Sudáfrica/epidemiología , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Infecciones Oportunistas/complicaciones , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/complicaciones , Recuento de Linfocito CD4
2.
J Stroke Cerebrovasc Dis ; 33(2): 107529, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38103446

RESUMEN

OBJECTIVES: We sought to identify what proportion of each cardiovascular risk factor and Human Immunodeficiency Virus (HIV) was first diagnosed at the time of stroke, compared to those that were diagnosed prior to the event, and to explore if this had any impact on the severity of stroke. METHODS: Adult patients presenting with a new stroke to a quaternary hospital in Johannesburg between 2014 and 2017 were prospectively recruited. Patients were investigated for undiagnosed traditional cardiovascular risk factors (hypertension, diabetes mellitus, dyslipidaemia, atrial fibrillation, obesity and smoking), as well as HIV infection. Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS). RESULTS: 346 patients were included. Stroke was the index presentation for at least one risk factor in 199 (57.5 %) patients. Dyslipidaemia was newly diagnosed in 76.0 % of all dyslipidaemics (95 out of 125). Newly-diagnosed dyslipidaemia was associated with a more severe neurological deficit (Median NIHSS of 12 (8-16) vs 7 (4-12), p=0.0007) and younger age on presentation (53 (44-63) years vs 62 (51-71) years, p=0.02) as compared to previously-diagnosed dyslipidaemia. CONCLUSIONS: More than half of patients had previously undiagnosed modifiable risk factors at the time of their stroke. Dyslipidaemia was undiagnosed in a very high proportion, and this was associated with a higher stroke severity and younger age of presentation.


Asunto(s)
Enfermedades Cardiovasculares , Dislipidemias , Infecciones por VIH , Accidente Cerebrovascular , Adulto , Humanos , Persona de Mediana Edad , Factores de Riesgo , Enfermedades Cardiovasculares/epidemiología , VIH , Infecciones por VIH/complicaciones , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Sudáfrica/epidemiología , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/complicaciones , Dislipidemias/diagnóstico , Dislipidemias/epidemiología , Dislipidemias/complicaciones , Factores de Riesgo de Enfermedad Cardiaca
3.
J Neurol Sci ; 451: 120710, 2023 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-37379726

RESUMEN

INTRODUCTION: In this brief report, we describe the nature of ALS in a South African cohort of patients of Black African ancestry - a population which has been historically understudied. METHODS: We performed a chart review of all patients attending the ALS/MND clinic at the Chris Hani Baragwanath Academic Hospital in Soweto, Johannesburg, South Africa, during the period 1 January 2015 to 30 June 2020. Cross-sectional demographic and clinical data captured at the time of diagnosis was collected. RESULTS: Seventy-one patients were included in the study. Males constituted 66% (n = 47), with a male to female sex ratio of 2:1. The median age at onset of symptoms was 46 years (IQR 40-57) with a median disease duration at diagnosis (diagnostic delay) of 2 years (IQR 1-3). The onset was spinal in 76% and bulbar in 23%. The median ALSFRS-R score at time of presentation was 29 (IQR 23-38.5). The median ALSFRS-R slope (unit/month) was 0.80 (IQR 0.43-1.39). Sixty five patients (92%) were diagnosed with the classic ALS phenotype. Fourteen patients were known to be HIV positive, and of those, 12 were on antiretroviral treatment (ART). None of the patients had familial ALS. CONCLUSION: Our findings of an earlier age at symptom onset and seemingly advanced disease at presentation in patients with Black African ancestry support the existing literature on the African population.


Asunto(s)
Esclerosis Amiotrófica Lateral , Enfermedad de la Neurona Motora , Femenino , Humanos , Masculino , Esclerosis Amiotrófica Lateral/diagnóstico , Estudios Transversales , Diagnóstico Tardío , Sudáfrica/epidemiología , Centros de Atención Terciaria , Adulto , Persona de Mediana Edad
4.
Front Cardiovasc Med ; 9: 971141, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36337883

RESUMEN

Aims: A lower heart rate (HR) increases central blood pressure through enhanced backward wave pressures (Pb). We aimed to determine whether these relationships are modified by increases in aortic stiffness. Methods: Using non-invasive central pressure, aortic velocity and diameter measurements in the outflow tract (echocardiography), we assessed the impact of aortic stiffness on relationships between HR and arterial wave morphology in 603 community participants < 60 years of age, 221 ≥ 60 years, and in 287 participants with arterial events [stroke and critical limb ischemia (CLI)]. Results: As compared to community participants < 60 years, those ≥ 60 years or with events had increased multivariate adjusted proximal aortic characteristic impedance (Zc) and carotid femoral pulse wave velocity (PWV) (p < 0.05 to < 0.0001). Community participants ≥ 60 years and those with events also had a greater slope of the inverse relationship between HR and Pb (p < 0.001 for comparison). While in community participants < 60 years, no interaction between indexes of aortic stiffness and HR occurred, in those ≥ 60 years (p < 0.02) and in those with arterial events (p = 0.001), beyond aortic root diameter, an interaction between Zc and HR, but not between PWV and HR independently associated with Pb. This translated into stepwise increases in the slope of HR-Pb relationships at incremental tertiles of Zc. Although HR was inversely associated with the systemic reflection coefficient in community participants ≥ 60 years (p < 0.0001), adjustments for the reflection coefficient failed to modify HR-Pb relations. Conclusion: Beyond the impact on systemic wave reflection, increases in proximal aortic stiffness enhance the adverse effects of HR on Pb and hence central BP.

5.
J Hypertens ; 39(4): 718-728, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-33186316

RESUMEN

AIM: We aimed to determine whether the impact of aortic stiffness on atherosclerotic or small vessel end organ damage beyond brachial blood pressure depends in-part on stiffness-induced increases in central arterial pressures produced by an enhanced resistance to flow (characteristic impedance, Zc). METHODS: We studied 1021 participants, 287 with stroke or critical limb ischaemia, and 734 from a community sample with atherosclerotic or small vessel end organ measures. Central arterial haemodynamics were determined from arterial pressure (SphygmoCor) and velocity and diameter assessments in the outflow tract (echocardiography). RESULTS: Although Zc and carotid-femoral pulse wave velocity (PWV) were correlated (P < 0.0001), these relations were not independent of confounders (P = 0.90). Both Zc and hence central arterial pressures generated by the product of Zc and aortic flow (Q) (PQxZc), as well as PWV were independently associated with carotid intima-media thickness, estimated glomerular filtration rate (eGFR), endothelial activation markers [vascular cell adhesion molecule-1 (V-CAM-1)] and events. With further adjustments for brachial pulse pressure (PP) or SBP, PWV and PQxZc were both associated with eGFR and V-CAM-1. Relationships between PWV and eGFR or V-CAM-1 were independent of PQxZc (P < 0.05) and relationships between PQxZc and eGFR and V-CAM-1 were independent of PWV (P < 0.005). Similarly, with adjustments for confounders and brachial PP or SBP, across the full adult lifespan, both aortic PWV and PQxZc were increased in those with arterial events (P < 0.005). Relationships between PWV and events were again independent of PQxZc (P < 0.005) and between PQxZc and events were independent of PWV (P < 0.0001). CONCLUSION: Beyond brachial blood pressure, the impact of aortic stiffness on arterial damage involves effects that are both dependent (proximal aortic Zc and hence PQxZc) and independent (full aortic length indexed by PWV) of central arterial pulsatile load. Hence, PWV and brachial PP may be insufficient to account for all of the damage mediated by increases in aortic stiffness.


Asunto(s)
Rigidez Vascular , Presión Sanguínea , Arteria Braquial/diagnóstico por imagen , Grosor Intima-Media Carotídeo , Humanos , Análisis de la Onda del Pulso
6.
Arterioscler Thromb Vasc Biol ; 40(6): 1574-1586, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32295423

RESUMEN

OBJECTIVE: The age at which arteriosclerosis begins to contribute to events is uncertain. We determined, across the adult lifespan, the extent to which arteriosclerosis-related changes in arterial function occur in those with precipitous arterial events (stroke and critical limb ischemia). Approaches and Results: In 1082 black South Africans (356 with either critical limb ischemia [n=238] or stroke [n=118; 35.4% premature], and 726 age, sex, and ethnicity-matched randomly selected controls), arterial function was evaluated from applanation tonometry and velocity and diameter measurements in the outflow tract. Compared with age- and sex-matched controls, over 10-year increments in age from 20 to 60years, multivariate-adjusted (including steady-state pressures) aortic pulse wave velocity, characteristic impedance (Zc), forward wave pressures (Pf), and early systolic pulse pressure amplification were consistently altered in those with arterial events. Increases in Zc were accounted for by aortic stiffness (no differences in aortic diameter) and Pf by changes in Zc and not aortic flow or wave re-reflection. Multivariate-adjusted pulse wave velocity (7.48±0.30 versus 5.82±0.15 m/s, P<0.0001), Zc (P<0.0005), and Pf (P<0.0001) were higher and early systolic pulse pressure amplification lower (P<0.0001) in those with precipitous events than in controls. In comparison to age- and sex-matched controls, independent of risk factors, pulse wave velocity, and Zc (P<0.005 and <0.05) were more closely associated with premature events than events in older persons and Pf and early systolic pulse pressure amplification were at least as closely associated with premature events as events in older persons. CONCLUSIONS: Arteriosclerosis-related changes in arterial function are consistently associated with arterial events beyond risk factors from as early as 20 years of age.


Asunto(s)
Arterias/fisiopatología , Arteriosclerosis/fisiopatología , Adulto , Anciano , Envejecimiento , Aorta/fisiopatología , Presión Arterial , Población Negra , Presión Sanguínea , Extremidades/irrigación sanguínea , Femenino , Humanos , Isquemia/fisiopatología , Masculino , Persona de Mediana Edad , Análisis de la Onda del Pulso , Factores de Riesgo , Sudáfrica , Accidente Cerebrovascular/fisiopatología , Rigidez Vascular
7.
Angiology ; 71(2): 122-130, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31303025

RESUMEN

The ability of carotid intima-media thickness (IMT) to predict risk beyond plaque is controversial. In 952 participants (critical limb ischemia [CLI] or stroke, n = 473; community, n = 479), we assessed whether relationships with events for IMT complement the impact of plaque in young patients depending on the extent of thrombotic versus atherosclerotic disease. The extent of atherosclerotic versus thrombotic occlusion was determined in 54 patients with CLI requiring amputations. Thrombotic occlusion in CLI was associated with younger age (P < .0001) and less plaque (P = .02). Independent relations between plaque and CLI were noted in older (>50 years; P < .005 to <.0001) but not younger (P > .38) participants, while independent relations between plaque and stroke (P < .005 to <.0001) and between IMT and CLI (P < .0001) were noted in younger participants. Although in performance (area under the receiver operating curve) for event detection, IMT thresholds failed to add to plaque alone in older patients (0.680 ± 0.020 vs 0.664 ± 0.017, P = .27), IMT improved performance for combined stroke and CLI detection when added to plaque in younger patients (0.719 ± 0.023 vs 0.631 ± 0.026, P < .0001). Because in younger participants the high prevalence of thrombotic occlusion in CLI is associated with less plaque, IMT adds information in associations with arterial vascular events.


Asunto(s)
Grosor Intima-Media Carotídeo , Isquemia/complicaciones , Isquemia/diagnóstico por imagen , Pierna/irrigación sanguínea , Pierna/diagnóstico por imagen , Placa Aterosclerótica/complicaciones , Placa Aterosclerótica/diagnóstico por imagen , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico por imagen , Trombosis/complicaciones , Trombosis/diagnóstico por imagen , Factores de Edad , Anciano , Enfermedad Crítica , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas
8.
Sci Rep ; 9(1): 4146, 2019 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-30858469

RESUMEN

Sulpiride (SPR) is a selective antagonist of central dopamine receptors but has limited clinical use due to its poor pharmacokinetics. The aim of this study was to investigate how metal ligation to SPR may improve its solubility, intestinal permeability and prolong its half-life. The synthesis and characterisation of ternary metal complexes [Ru(p -cymene)(L)(SPR)]PF6 (L1 = (R)-(+)-2-amino-3-phenyl-1-propanol, L2 = ethanolamine, L3 = (S)-(+)-2-amino-1-propanol, L4 = 3-amino-1-propanol, L5 = (S)-(+)-2-pyrrolidinemethanol) are described in this work. The stability constant of the [Ru(p -cymene)(SPR)] complex was determined using Job's method. The obtained value revealed higher stability of the metal complex in the physiological pH than in an acidic environment such as the stomach. The ternary metal complexes were characterised by elemental analysis, Fourier transform infrared spectroscopy (FT-IR), 1H and 13C nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), thermal analyses, Ultraviolet-Visible (UV-Vis). Solubility studies showed higher aqueous solubility for complexed SPR than the free drug. Dissolution profiles of SPR from the metal complexes exhibited slower dissolution rate of the drug. Permeation studies through the pig's intestine revealed enhanced membrane permeation of the complexed drug. In vitro methyl thiazolyl tetrazolium (MTT) assay showed no noticeable toxic effects of the ternary metal complexes on Caco-2 cell line.


Asunto(s)
Antagonistas de Dopamina/síntesis química , Compuestos de Rutenio/síntesis química , Sulpirida/análogos & derivados , Animales , Células CACO-2 , Antagonistas de Dopamina/farmacocinética , Antagonistas de Dopamina/toxicidad , Humanos , Absorción Intestinal , Propanolaminas/química , Compuestos de Rutenio/farmacocinética , Compuestos de Rutenio/toxicidad , Porcinos
9.
J Hypertens ; 37(4): 795-804, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30817461

RESUMEN

AIM: Although chronic kidney disease (CKD) as determined from estimated glomerular filtration rate (eGFR) is recommended for risk prediction by current hypertension guidelines, the equations to derive eGFR may not perform well in black Africans. We compared whether across the adult lifespan, eGFR or CKD are as closely associated with noncardiac arterial vascular events, as carotid intima-media thickness (IMT), in Africa. METHODS: In 1152 black South Africans [480 with noncardiac arterial events (294 with critical lower limb ischemia, 186 with stroke) of which 37% were premature] and 672 age, sex and ethnicity-matched controls from a randomly selected community sample, we assessed relations between eGFR, CKD or carotid IMT (B-mode ultrasound) and arterial events. RESULTS: From 20 years until old age, with or without adjustments, IMT was increased in those with as compared with without events (P < 0.01 at each decade of age). However, at any decade of age across the adult lifespan neither creatinine concentrations, nor eGFR were altered in those with arterial events (P > 0.28). Although IMT was strongly and independently associated with the odds of an event [odds ratio per 1 SD (0.171 mm) effect = 2.19, confidence interval = 1.75-2.78, P < 0.0001], neither creatinine concentrations (P = 0.89), modification of diet in renal disease-derived (P = 0.07), nor Chronic Kidney Disease Epidemiology Collaboration-derived [odds ratio per 1 SD (22.5 ml/min per 1.73 m) effect = 1.06, confidence interval = 0.89-1.27, P = 0.51] eGFR were independently associated with the odds of an event. Although many with premature events had an increased IMT (63%), few with either premature events (8%) or with events at an older age (21%) had CKD and CKD had a poor performance (0.539 ±â€Š0.011) and low sensitivity (16%) for event detection. CONCLUSION: In black South Africans, despite carotid IMT strongly associating with noncardiac arterial vascular events (stroke and critical lower limb ischaemia) consistently across the adult lifespan, few with events have CKD and CKD fails to associate with events.


Asunto(s)
Grosor Intima-Media Carotídeo , Tasa de Filtración Glomerular , Isquemia/etiología , Insuficiencia Renal Crónica/complicaciones , Accidente Cerebrovascular/etiología , Adulto , Anciano , Arterias/fisiopatología , Población Negra , Creatinina/sangre , Femenino , Humanos , Hipertensión/complicaciones , Isquemia/epidemiología , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/epidemiología , Sudáfrica/epidemiología , Accidente Cerebrovascular/epidemiología , Ultrasonografía
10.
Int J Pharm ; 559: 255-270, 2019 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-30690131

RESUMEN

The purpose of this work was to develop an in situ thermosensitive electro-responsive mucoadhesive gel loaded with bioactive agent (nanocomposite) meant for nose to brain delivery in a controllable manner when electric stimulation is applied. Nanocomposite was developed using a combinatorial blending of chitosan, hydroxypropylmethylcellulose, pluronic F127 and polyaniline which was then loaded with BCNU-Nano-co-Plex (the bioactive agent). The nanocomposite was a liquid at room temperature but formed an in situ mucogel at a temperature of 27.5 ±â€¯0.5 °C. Furthermore, the nanocomposite possessed a redox element which makes it responsive to electrical stimulation (ES). The stimuli responsiveness enabled the formulation to release the bioactive agent when electrical potential was applied and demonstrated a desired 10.28% release of nanoparticles per application cycle. The results further revealed pore formation within the formulation which accommodated the loaded nanoparticles. The release profile also demonstrated a pulsatile release of the bioactive material when subjected to ES. This formulation may therefore be useful as a nose to brain drug delivery system that can be modulated to deliver bioactive agents to the brain via electro-actuation in an "on-off" drug release kinetics by means of an external ES for a controlled nose-to-brain delivery.


Asunto(s)
Preparaciones de Acción Retardada/química , Geles/química , Administración Intranasal/métodos , Quitosano/química , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Liberación de Fármacos , Derivados de la Hipromelosa/química , Nanopartículas/química , Poloxámero/química , Polímeros/química , Temperatura
11.
Br J Neurosurg ; 33(3): 253-254, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28298140

RESUMEN

Spinal tumours in pregnancy are rare. Spinal tumours account for only 10-15% of all primary central nervous system (CNS) tumours. Most spinal tumours in pregnant women have been described as meningiomas or vascular tumours. We present the unique case of a pregnant patient presenting with a CD 99+ primary spinal central PNET.


Asunto(s)
Antígeno 12E7/análisis , Tumores Neuroectodérmicos Primitivos/inmunología , Tumores Neuroectodérmicos Primitivos/terapia , Complicaciones Neoplásicas del Embarazo/terapia , Neoplasias de la Médula Espinal/inmunología , Neoplasias de la Médula Espinal/terapia , Adulto , Terapia Combinada , Femenino , Humanos , Enfermedades Neuromusculares/etiología , Procedimientos Neuroquirúrgicos , Embarazo , Complicaciones Neoplásicas del Embarazo/cirugía , Neoplasias de la Médula Espinal/cirugía , Resultado del Tratamiento
12.
J Pharm Pharm Sci ; 21(1): 94-109, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29510799

RESUMEN

PURPOSE: This study aimed to develop and analyse poly(DL-lactic acid)-methacrylic acid nanospheres bound to the chelating ligand diethylenetriaminepentaacetic acid (DTPA)  for the targeted delivery of amantadine in Amyotrophic Lateral Sclerosis (ALS). METHODS: The nanospheres were prepared by a double emulsion solvent evaporation technique statistically optimized employing a 3-Factor Box-Behnken experimental design. Analysis of the particle size, zeta potential, polydispersity (Pdl), morphology, drug entrapment and drug release kinetics were carried out. RESULTS: The prepared nanospheres were determined to have particle sizes ranging from 68.31 to 113.6 nm (Pdl ≤ 0.5). An initial burst release (50% of amantadine released in 24 hr) was also obtained, followed by a prolonged release phase of amantadine over 72 hr. Successful conjugation of the chelating ligand onto the surface of the optimised nanospheres was thereafter achieved and confirmed by TEM. The synthesized modified nanospheres were spherical in shape, 105.6 nm in size, with a PdI of 0.24 and zeta potential of -28.0 mV. Conjugation efficiency was determined to be 74%. In vitro and ex vivo cell study results confirmed the intracellular uptake of the modified nanospheres by the NSC-34 cell line and the non-cytotoxicity of the synthesized nanospheres. CONCLUSIONS: Biocompatible amantadine-loaded nanospheres were successfully designed, characterized and optimized employing the randomized Box-Behnken statistical design. Delivery of amantadine over 72 hrs was achieved, with the nanospheres being of a size capable of internalization by the NSC- 34 cells. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.


Asunto(s)
Amantadina/uso terapéutico , Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Antiparkinsonianos/uso terapéutico , Metacrilatos/química , Nanosferas/química , Ácido Pentético/química , Amantadina/química , Animales , Antiparkinsonianos/química , Células Cultivadas , Sistemas de Liberación de Medicamentos , Ligandos , Ratones , Poliésteres/química
13.
Parkinsons Dis ; 2017: 7818123, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28529814

RESUMEN

One approach for delivery of narrow absorption window drugs is to formulate gastroretentive drug delivery systems. This study was undertaken to provide insight into in vivo performances of two gastroretentive systems (PXLNET and IPB matrices) in comparison to Madopar® HBS capsules. The pig model was used to assess gastric residence time and pharmacokinetic parameters using blood, cerebrospinal fluid (CSF), and urine samples. Histopathology and cytotoxicity testing were also undertaken. The pharmacokinetic parameters indicated that levodopa was liberated from the drug delivery systems, absorbed, widely distributed, metabolized, and excreted. Cmax were 372.37, 257.02, and 461.28 ng/mL and MRT were 15.36, 14.98, and 13.30 for Madopar HBS capsules, PXLNET, and IPB, respectively. In addition, X-ray imaging indicated that the gastroretentive systems have the potential to reside in the stomach for 7 hours. There was strong in vitro-in vivo correlation for all formulations with r2 values of 0.906, 0.935, and 0.945 for Madopar HBS capsules, PXLNET, and IPB, respectively. Consequently, PXLNET and IPB matrices have pertinent potential as gastroretentive systems for narrow absorption window drugs (e.g., L-dopa) and, in this application specifically, enhanced the central nervous system and/or systemic bioavailability of such drugs.

14.
AAPS PharmSciTech ; 18(7): 2479-2493, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28205143

RESUMEN

A multifunctional platform to deliver three diverse proteins of insulin, interferon beta (INF-ß) and erythropoietin (EPO), using a novel copolymeric microparticulate system of TMC-PEGDMA-MAA, was synthesised as an intelligent pH-responsive 2-fold gastric and intestinal absorptive system. Physiochemical and physicomechanical studies proved the degree of crystallinity that supported the controlled protein delivery of the microparticulate system. The copolymer was tableted before undertaking in vitro and in vivo analysis. After 2.5 h in simulated gastric fluid (SGF), insulin showed a fractional release of 3.2% in comparison to simulated intestinal fluid (SIF), in which a maximum of 83% of insulin was released. Similarly, INF-ß and EPO released 3 and 9.7% in SGF and a maximum of 74 and 81.3% in SIF, respectively. In vivo studies demonstrated a significant decrease in blood glucose by 54.19% within 4 h post-dosing, and the comparator formulation provided 74.6% decrease in blood glucose within the same time period. INF-ß peak bioavailable dose in serum was calculated to be 1.3% in comparison to an SC formulation having a peak concentration of 0.9%, demonstrating steady-state release for 24 h. EPO-loaded copolymeric microparticles had a 1.6% peak bioavailable concentration, in comparison to the 6.34% peak concentration after 8 h from the SC comparator formulation.


Asunto(s)
Eritropoyetina/administración & dosificación , Insulina/administración & dosificación , Interferón beta/administración & dosificación , Administración Oral , Animales , Disponibilidad Biológica , Glucemia/análisis , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Absorción Gástrica , Concentración de Iones de Hidrógeno , Interferón beta/sangre , Metacrilatos/química , Polietilenglicoles/química , Conejos
15.
J Pharm Sci ; 106(4): 1111-1116, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28057546

RESUMEN

With a significant portion of the world suffering from chronic pain, the management and treatment of this condition still requires extensive research to successfully mobilize and functionalize its sufferers. This article details the in vitro and in vivo evaluation of a transdermal electro-modulated hydrogel-microneedle array (EMHM) device for the treatment of chronic pain. In vitro characterization of the electro-modulated hydrogel was undertaken before the determination of the in vivo release, histopathologic and pharmacokinetic profiles of the EMHM in a Sprague Dawley rat model. Pharmacokinetic modeling was conducted to establish a level A in vitro-in vivo correlation. Data analysis was carried out by segmenting the combined in vivo release profile into individualistic profiles before analysis.


Asunto(s)
Analgesia/métodos , Sistemas de Liberación de Medicamentos/métodos , Hidrogel de Polietilenoglicol-Dimetacrilato/administración & dosificación , Hidrogel de Polietilenoglicol-Dimetacrilato/metabolismo , Microinyecciones/métodos , Absorción Cutánea/fisiología , Administración Cutánea , Animales , Estimulación Eléctrica/métodos , Ratas , Ratas Sprague-Dawley , Absorción Cutánea/efectos de los fármacos
16.
Pharm Dev Technol ; 22(4): 476-486, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27268737

RESUMEN

The complexity of the brain and the membranous blood-brain barrier (BBB) has proved to be a significant limitation to the systemic delivery of pharmaceuticals to the brain rendering them sub-therapeutic and ineffective in the treatment of neurological diseases. Apart from this, lack of innovation in product development to counteract the problem is also a major contributing factor to a poor therapeutic outcome. Various innovative strategies show potential in treating some of the neurological disorders; however, drug delivery remains the most popular. To attain therapeutic drug levels in the central nervous system, large, intolerable systemic doses are generally administered. The major factors responsible for the success maintenance therapy of neurological diseases included controlled and sustained release of neurotherapeutics, reduced frequency of administration, higher bioavailability, and patient compliances. Conventional oral or injectable formulations cannot satisfy all the requirements in many circumstances. This article reviews the therapeutic implantable polymeric and transdermal devices employed in an attempt to effectively achieve therapeutic quantities of drug across the BBB over a prolonged period, to improve patient disease prognosis.


Asunto(s)
Fármacos del Sistema Nervioso Central/administración & dosificación , Enfermedades del Sistema Nervioso Central/tratamiento farmacológico , Sistemas de Liberación de Medicamentos/métodos , Implantes de Medicamentos/química , Polímeros/química , Administración Cutánea , Animales , Barrera Hematoencefálica/metabolismo , Sistema Nervioso Central/metabolismo , Sistemas de Liberación de Medicamentos/instrumentación , Humanos
17.
AAPS PharmSciTech ; 18(3): 671-685, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27188761

RESUMEN

The purpose of this study was to explore the use of molecular bio-imaging systems and biomechanical dynamics to elucidate the fate of a nanocomposite hydrogel system prepared by merging FITC-labeled nanolipobubbles within a cross-linked hydrogel network. The nanocomposite hydrogel system was characterized by size distribution analysis and zeta potential as well as shears thinning behavior, elastic modulus (G'), viscous loss moduli (G"), TEM, and FTIR. In addition, molecular bio-imaging via Vevo ultrasound and Cell-viZio techniques evaluated the stability and distribution of the nanolipobubbles within the cross-linked hydrogel. FITC-labeled and functionalized nanolipobubbles had particle sizes between 135 and 158 nm (PdI = 0.129 and 0.190) and a zeta potential of -34 mV. TEM and ultrasound imaging revealed the uniformity and dimensional stability of the functionalized nanolipobubbles pre- and post-embedment into the cross-linked hydrogel. Biomechanical characterization of the hydrogel by shear thinning behavior was governed by the polymer concentration and the cross-linker, glutaraldehyde. Ultrasound analysis and Cell-viZio bio-imaging were highly suitable to visualize the fluorescent image-guided nanolipobubbles and their morphology post-embedment into the hydrogel to form the NanoComposite system. Since the nanocomposite is intended for targeted treatment of neurodegenerative disorders, the distribution of the functionalized nanolipobubbles into PC12 neuronal cells was also ascertained via confocal microscopy. Results demonstrated effective release and localization of the nanolipobubbles within PC12 neuronal cells. The molecular structure of the synthetic surface peptide remained intact for an extended period to ensure potency for targeted delivery from the hydrogel ex vivo. These findings provide further insight into the properties of nanocomposite hydrogels for specialized drug delivery.


Asunto(s)
Hidrogel de Polietilenoglicol-Dimetacrilato/química , Nanocompuestos/química , Animales , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos/métodos , Fluoresceína-5-Isotiocianato/química , Hidrogel de Polietilenoglicol-Dimetacrilato/metabolismo , Células PC12 , Tamaño de la Partícula , Ratas , Distribución Tisular/efectos de los fármacos
18.
Drug Discov Today ; 21(12): 1886-1914, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27506871

RESUMEN

Historically, neuropsychiatric and neurodegenerative disease treatments focused on the 'magic bullet' concept; however multi-targeted strategies are increasingly attractive gauging from the escalating research in this area. Because these diseases are typically co-morbid, multi-targeted drugs capable of interacting with multiple targets will expand treatment to the co-morbid disease condition. Despite their theoretical efficacy, there are significant impediments to clinical success (e.g., difficulty titrating individual aspects of the drug and inconclusive pathophysiological mechanisms). The new and revised diagnostic frameworks along with studies detailing the endophenotypic characteristics of the diseases promise to provide the foundation for the circumvention of these impediments. This review serves to evaluate the various marketed and nonmarketed multi-targeted drugs with particular emphasis on their design strategy.


Asunto(s)
Trastornos Mentales/tratamiento farmacológico , Enfermedades Neurodegenerativas/tratamiento farmacológico , Animales , Diseño de Fármacos , Humanos , Ligandos
19.
Expert Opin Drug Deliv ; 13(7): 1029-43, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26967508

RESUMEN

INTRODUCTION: Neurodegenerative diseases (NDs) represent intricate challenges for efficient uptake and transport of drugs to the brain mainly due to the restrictive blood-brain barrier (BBB). NDs are characterized by the loss of neuronal subtypes as sporadic and/or familial and several mechanisms of neurodegeneration have been identified. AREAS COVERED: This review attempts to recap, organize and concisely evaluate the advanced drug delivery systems designed for treating common NDs. It highlights key research gaps and opinionates on new neurotherapies to overcome the BBB as an addition to the current treatments of countering oxidative stress, inflammation and apoptotic mechanisms. EXPERT OPINION: Current treatments do not fully address the biological, drug and therapeutic factors faced. This has led to the development of vogue treatments such as nose-to-brain technologies, bio-engineered systems, fusion protein chaperones, stem cells, gene therapy, use of natural compounds, neuroprotectants and even vaccines. However, failure of these treatments is mainly due to the BBB and non-specific delivery in the brain. In order to increase neuroavailability various advanced drug delivery systems provide promising alternatives that are able to augment the treatment of Alzheimer's disease and Parkinson's disease. However, much work is still required in this field beyond the preclinical testing phase.


Asunto(s)
Barrera Hematoencefálica/metabolismo , Sistemas de Liberación de Medicamentos , Enfermedades Neurodegenerativas/tratamiento farmacológico , Encéfalo/metabolismo , Humanos , Enfermedad de Parkinson/tratamiento farmacológico , Preparaciones Farmacéuticas/administración & dosificación
20.
J Neurol Sci ; 363: 39-42, 2016 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-27000218

RESUMEN

OBJECTIVE: To describe patients with Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) in Johannesburg, South Africa, a setting of high HIV prevalence, and to determine the influence, if any, of HIV on CIDP. METHODS: Patients were recruited prospectively. The study design was a hospital based case series of unselected consecutive CIDP patients. CIDP was diagnosed according to the European Federation of Neurological Societies/Peripheral Nerve Society criteria for the diagnosis of CIDP (First Revision). Demographic, clinical, laboratory and electrophysiological data were documented. RESULTS: Twenty three patients with CIDP were recruited over a two year period. Mean age was 38 years. The female to male ratio was 3.6:1. Less than half (43%) had a raised cerebrospinal fluid (CSF) protein. All patients had idiopathic CIDP, three had associated diabetes mellitus. Ten patients (43%) were HIV positive. Thirteen patients were HIV negative. Clinical and electrophysiological characteristics were identical in the two groups. In the HIV positive group all the patients were black females. The CD4 counts ranged from 87 to 747 cells/mm(3). HIV positive status was associated with a progressive disease course and significantly with a CSF lymphocytic pleocytosis (p=0.007). Albuminocytological dissociation was associated with HIV negative status. CONCLUSIONS: Testing for HIV in patients with CIDP in a region of high HIV prevalence is recommended. CSF lymphocytic pleocytosis occurs in HIV associated CIDP.


Asunto(s)
Enfermedades Endémicas , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/diagnóstico , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/epidemiología , Adolescente , Adulto , Anciano , Niño , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sudáfrica/epidemiología , Adulto Joven
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