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1.
J Am Chem Soc ; 146(37): 25745-25754, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39226399

RESUMEN

Developing a mechanistic understanding of catalyzed melt-phase depolymerization processes is of utmost importance to the rapidly expanding field of circular polymers with a closed chemical loop. Herein, we present a methodology to probe the mechanism of metal-catalyzed melt-phase depolymerization of polyesters utilizing an approach centered on studies of kinetics by thermogravimetric analysis and model reactions. Kinetic parameters associated with the prototypical Lewis-acid-catalyzed depolymerization of representative polyesters, including poly(δ-valerolactone) (PVL), poly(lactic acid), and poly(γ-butyrolactone), are elucidated. Focusing on PVL for further investigation of the depolymerization mechanism, effects of its molar mass, topology, and end-group chemistry are examined in detail. Overall, a catalyzed ring-closing depolymerization process to monomer from the polyester hydroxyl-chain ends is proposed as the key mechanistic step, although the process has a relatively large zip length (≈ 320) and follows nonimmortal depolymerization kinetics.

2.
J Am Chem Soc ; 146(43): 29895-29904, 2024 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-39413833

RESUMEN

Within the large poly(3-hydroxyalkanoate) (PHA) family, C3 propionates are much less studied than C4 butyrates, with the exception of α,α-disubstituted propionate PHAs, particularly poly(3-hydroxy-2,2-dimethylpropionate), P3H(Me)2P, due to its high melting temperature (Tm ∼ 230 °C) and crystallinity (∼76%). However, inefficient synthetic routes to its monomer 2,2-dimethylpropiolactone [(Me)2PL] and extreme brittleness of P3H(Me)2P largely hinder its broad applications. Here, we introduce simple, efficient step-growth polycondensation (SGP) of a hydroxyacid or methyl ester to afford P3H(Me)2P with low to medium molar mass, which is then utilized to produce lactones through base-catalyzed depolymerization. The ring-opening polymerization (ROP) of the 4-membered lactone leads to high-molar-mass P3H(Me)2P, which can be depolymerized by hydrolysis to the hydroxyacid in 99% yield or methanolysis to the hydroxyester in 91% yield, achieving closed-loop recycling via both SGP and ROP routes. Intriguingly, the chain end of the SGP-P3H(Me)2P determines the depolymerization selectivity toward 4- or 12-membered lactone formation, while both can be repolymerized back to P3H(Me)2P. Through the formation of copolymers P3H(Me/R)2P (R = Et, nPr), PHAs with high tensile strength and ductility, coupled with high barriers to water vapor and oxygen, have been created. Notably, the PHA structure-property study led to P3H(nPr)2P with a record-high Tm of 266 °C within the PHA family.

3.
Planta ; 260(1): 10, 2024 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-38796805

RESUMEN

MAIN CONCLUSION: Brown-top millet is a lesser-known millet with a high grain nutrient value, early maturation, and drought tolerance that needs basic research to understand and conserve food security. Brown-top millet [Urochloa ramosa (L.)] is currently cultivated in some developing countries (especially in India) for food and fodder, although it is less known among the small millets. Like other millets, it contains macro- and micronutrients, vitamins, minerals, proteins, and fiber, all of which have rich health benefits. The nutritional importance and health benefits of brown-top millet are still unknown to many people due to a lack of awareness, wide cultivation, and research. Hence, this millet is currently overshadowed by other major cereals. This review article aims to present the nutritional, breeding, genetic, and genomic resources of brown-top millet to inform millet and other plant researchers. It is important to note that genetic and genomic resources have not yet been created for this millet. To date, there are no genomic and transcriptomic resources for brown-top millet to develop single nucleotide polymorphisms (SNP) and insertion/Deletions (InDels) for breeding studies. Furthermore, studies regarding nutritional significance and health benefits are required to investigate the exact nutritional contents and health benefits of the brown-top millet. The present review delves into the nutritional value and health advantages of brown-top millet, as supported by the available literature. The limitations of producing brown-top millet have been enumerated. We also cover the status of marker-assisted breeding and functional genomics research on closely related species. Lastly, we draw insights for further research such as developing omics resources and applying genome editing to study and improve brown-top millet. This review will help to start breeding and other molecular studies to increase the growth and development of this cereal.


Asunto(s)
Mijos , Fitomejoramiento , Mijos/genética , Fitomejoramiento/métodos , Genómica , Productos Agrícolas/genética , Valor Nutritivo , Genoma de Planta/genética , Grano Comestible/genética
4.
Angew Chem Int Ed Engl ; 62(26): e202303791, 2023 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-37102633

RESUMEN

Chemically recyclable, circular polymers continue to attract increasing attention, but rendering both catalysts for depolymerization and high-performance polymers recyclable is a more sustainable yet challenging goal. Here we introduce a dual catalyst/polymer recycling system in that recyclable inorganic phosphomolybdic acid catalyzes selective depolymerization of high-ceiling-temperature biodegradable poly(δ-valerolactone) in bulk phase, which, upon reaching suitable molecular weight, exhibits outstanding mechanical performance with a high tensile strength of ≈66.6 MPa, fracture strain of ≈904 %, and toughness of ≈308 MJ m-3 , and thus markedly outperforms commodity polyolefins, recovering its monomer in pure state and quantitative yield at only 100 °C. In sharp contrast, the uncatalyzed depolymerization not only requires a high temperature of >310 °C but is also low yielding and non-selective. Importantly, the recovered monomer can be repolymerized as is to reproduce the same polymer, thereby closing the circular loop, and the recycled catalyst can be reused repeatedly for depolymerization runs without loss of its catalytic activity and efficiency.


Asunto(s)
Poliésteres , Polímeros , Poliésteres/química , Polímeros/química , Polienos , Catálisis
5.
J Appl Microbiol ; 131(3): 1417-1430, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33522007

RESUMEN

AIMS: To characterize the mechanisms by which bacteria in the peanut rhizosphere promote plant growth and suppress Aspergillus niger, the fungus that causes collar rot of peanut. METHODS AND RESULTS: In all, 131 isolates cultured from the peanut rhizosphere were assayed for growth promotion in a seedling germination assay. The most effective isolate, RR18, was identified as Burkholderia sp. by 16S sequencing analysis. RR18 reduced collar rot disease incidence and increased the germination rate and biomass of peanut seeds, and had broad-spectrum antifungal activity. Quantitative analyses showed that RR18 induced long-lasting accumulation of jasmonic acid, salicylic acid and phenols, and triggered the activity of six defence enzymes related to these changes. Comparative proteomic analysis of treated and untreated seedlings revealed a clear induction of four abundant proteins, including a member of the pre-chorismate pathway, a regulator of clathrin-coated vesicles, a transcription factor and a hypothetical protein. CONCLUSION: Burkholderia sp. RR18 promotes peanut growth and disease resistance, and stably induces two distinct defence pathways associated with systemic resistance. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates that a strain of the Burkholderia cepacia complex can elicit both salicylic- and jasmonic-acid-mediated defences, in addition to having numerous other beneficial properties.


Asunto(s)
Arachis , Burkholderia , Ácido Corísmico/metabolismo , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Ácido Salicílico/metabolismo , Antibiosis , Arachis/microbiología , Aspergillus niger/patogenicidad , Burkholderia/metabolismo , Enfermedades de las Plantas/prevención & control , Proteómica , Plantones/microbiología
6.
Br J Surg ; 107(4): 355-363, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31912491

RESUMEN

BACKGROUND: Supervised exercise programmes for intermittent claudication have poor access and limited compliance. Neuromuscular electrical stimulation (NMES) may be an effective alternative. A proof-of-concept study and RCT were conducted. METHODS: In study 1, eligible patients underwent baseline assessment; treadmill testing for initial (ICD) and maximum (MCD) claudication distance; EuroQoL Five Dimensions five-level instrument (EQ-5D-5L™) and Intermittent Claudication Questionnaire (ICQ) assessment; and measurement of ultrasound haemodynamics of the superficial femoral artery. After familiarization with the NMES device, participants underwent a 30-min session of stimulation with concomitant recording of haemodynamic measures at 15 min, and after device cessation. Measurements were repeated after 6 weeks of daily use of NMES. In study 2, consecutive patients underwent baseline assessment before online randomization to a supervised exercise programme only, or adjunctive NMES treatment for 6 weeks, followed by repeat measurements. RESULTS: Study 1 (20 patients) showed a significant improvement in MCD (46 per cent; P < 0·001) and ICD (71 per cent; P < 0·001). The RCT (42 patients) showed a significant adjunctive benefit of NMES in ICD (46 per cent; P = 0·014). Improvements were seen in the ICQ (9 points; P = 0·009) and EQ-5D-5L™ (P = 0·007) in study 1, and there was a significant adjunctive benefit of NMES on the ICQ score in patients who did supervised exercise (11·2 points; P = 0·031). Blood volume flow and time-adjusted mean velocity increased significantly with the device on (P < 0·050). Overall, NMES compliance exceeded 95 per cent. CONCLUSION: Footplate NMES significantly improved walking distance in patients with intermittent claudication when used independently and also as an adjunct to supervised exercise. Registration number: trial 1, NCT02436200; trial 2, NCT02429310 (http://www.clinicaltrials.gov).


ANTECEDENTES: Los programas de ejercicio supervisado (supervised exercise programmes, SEP) para la claudicación intermitente (intermittent claudication, IC) tienen un acceso y un cumplimiento deficientes. La estimulación eléctrica neuromuscular (neuromuscular electrical stimulation, NMES) puede ser una alternativa clínicamente efectiva. Se realizó un estudio de prueba de concepto y un ensayo controlado aleatorizado. MÉTODOS: Estudio 1: Veinte pacientes elegibles se sometieron a una evaluación inicial que incluía una prueba en la cinta de correr para la distancia inicial de claudicación (initial claudication distance, ICD) y la distancia máxima de claudicación (maximum claudication distance, MCD), EuroQoL-5D (EQ-5D), valoración mediante el cuestionario de claudicación intermitente (intermittent claudication questionnaire, ICQ), y hemodinámica por ecografía de la arteria femoral superficial. Después de familiarizarse con el dispositivo NMES, los participantes se sometieron a una sesión de estimulación de 30 minutos con el registro concomitante de medidas hemodinámicas a los 15 minutos y después del cese del dispositivo. Se realizaron mediciones repetidas después de 6 semanas de uso diario de NMES. Estudio 2: Se reclutaron 42 pacientes que tras una evaluación inicial y posterior aleatorización al azar en línea, se asignaron al Grupo A, utilizando SEP solamente; o al el Grupo B, con tratamiento NMES complementario durante 6 semanas seguido de medidas repetidas. RESULTADOS: El estudio 1 mostró una mejoría significativa de la MCD (46%, P < 0,0001) y de la ICD (71%, P < 0.004). El ensayo clínico mostró un beneficio coadyuvante significativo de NMES en la ICD (46%, P = 0,014). Se observaron mejorías en la puntuación del ICQ (9 puntos, P < 0,01) y del EQ-5D (P < 0,05) en el estudio 1, con un beneficio coadyuvante significativo de NMES en la puntuación del ICQ (11 puntos, P < 0,05). El flujo de volumen de sangre (CC/min) y TAMV (cm/s) aumentaron significativamente con el dispositivo en funcionamiento (P < 0,05). El cumplimiento global de la NMES superó el 95%. CONCLUSIÓN: La plataforma de NMES para el pie mejora significativamente las distancias de caminar en la claudicación intermitente cuando se usa de forma independiente y también proporciona un beneficio complementario al ejercicio supervisado en la distancia caminada sin dolor. La mejora del flujo sanguíneo puede ser un mecanismo para explicar estos resultados.


Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Estimulación Eléctrica/métodos , Enfermedad Arterial Periférica/terapia , Calidad de Vida , Anciano , Terapia por Ejercicio , Femenino , Arteria Femoral/diagnóstico por imagen , Pie/inervación , Humanos , Claudicación Intermitente/psicología , Claudicación Intermitente/terapia , Masculino , Enfermedad Arterial Periférica/psicología , Proyectos Piloto , Encuestas y Cuestionarios , Ultrasonografía
7.
Med J Armed Forces India ; 74(3): 227-234, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30093765

RESUMEN

BACKGROUND: The differentiation between the causes of cervical lymphadenopathy is of paramount importance as these have different modalities of treatment with varying prognosis. The aim of this study was to evaluate the efficacy of B Mode and colour Doppler ultrasound (CDUS) to differentiate between benign and metastatic lymph nodes. METHODS: 100 patients of clinically palpable lymph nodes were evaluated with B Mode and CDUS. B Mode assessment included short-long (S:L) axis ratio, hilum, nodal border, echogenicity, intranodal necrosis and ancillary features. CDUS assessment included distribution of vascularity, resistive index (RI) and pulsatility index (PI). Statistical analysis was carried out with histopathological or cytological diagnosis as gold standard. RESULTS: B-Mode US correctly diagnosed 22/25 (88%) of the reactive lymph nodes giving it a sensitivity of 88% and specificity of 97.3%. Colour Doppler US diagnosed 23/25 (92%) reactive lymph nodes with a sensitivity of 92% and specificity of 97.3%. B-Mode underdiagnosed one case each of granulomatous disease and metastasis as reactive node while CDUS missed out two cases of granulomatous disease as reactive lymph node. CONCLUSION: Individual parameters of B Mode when used alone were not found to be very effective in differentiating benign and malignant lymph nodes. However features of B-Mode combined together as well as color Doppler ultrasound, help in the detection of reactive lymph nodes and can be used as a diagnostic tool with good accuracy. However, they cannot be used as a diagnostic method for metastatic or tubercular nodes and cytopathology/histopathology remains the gold standard in such situations.

8.
Med J Armed Forces India ; 74(1): 11-17, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29386725

RESUMEN

BACKGROUND: Tuberculosis of spine is known as tubercular spondylitis or Pott's spine. The vertebral involvement leads to various pathological processes such as abscess formation, cord compression, and gibbus deformity. Magnetic Resonance Imaging (MRI) is the imaging modality of choice which not only helps in diagnosing a case of Pott's spine but also gives valuable information about its impending complications, thereby, aiding in management of these cases. METHODS: In this study, MRI scans of 80 proven cases of tubercular spondylitis were studied retrospectively for the various pathological processes affecting the spine. RESULTS: Of the 80 cases included in this study, 68.8% of cases were male and 31.2% of cases were females. Majority of cases were seen in 21-40 yrs age group. Lumbar vertebrae were more commonly affected than the dorsal vertebrae. Contiguous two vertebral involvement was the most common pattern, and skip lesions were seen in 5% of cases. Pre-, paravertebral and epidural soft tissue component was seen in 96.25% and 62.5% of cases, respectively. Intervertebral disc Involvement was noted in 95% of cases, and cord edema was seen in 15% of cases. CONCLUSION: Tubercular spondylitis or Pott's spine is an extrapulmonary form of tuberculosis which affects the spine. MRI is the imaging modality of choice not only in diagnosing the condition but also in guiding the surgical management. The cases of spinal tuberculosis were systematically analyzed for various pathological lesions which are produced in the spine as the disease progresses.

9.
Br J Surg ; 104(11): 1539-1548, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28833055

RESUMEN

BACKGROUND: The International Study Group of Pancreatic Surgery (ISGPS) recommends operative exploration and resection of pancreatic cancers in the presence of reconstructable mesentericoportal axis involvement. However, there is no consensus on the ideal method of vascular reconstruction. The effect of depth of tumour invasion of the vessel wall on outcome is also unknown. METHODS: This was a retrospective cohort study of pancreaticoduodenectomy with vein resection for T3 adenocarcinoma of the head of the pancreas across nine centres. Outcome measures were overall survival based on the impact of the depth of tumour infiltration of the vessel wall, and morbidity, in-hospital mortality and overall survival between types of venous reconstruction: primary closure, end-to-end anastomosis and interposition graft. RESULTS: A total of 229 patients underwent portal vein resection; 129 (56·3 per cent) underwent primary closure, 64 (27·9 per cent) had an end-to-end anastomosis and 36 (15·7 per cent) an interposition graft. There was no difference in overall morbidity (26 (20·2 per cent), 14 (22 per cent) and 9 (25 per cent) respectively; P = 0·817) or in-hospital mortality (6 (4·7 per cent), 2 (3 per cent) and 2 (6 per cent); P = 0·826) between the three groups. One hundred and six patients (47·5 per cent) had histological evidence of vein involvement; 59 (26·5 per cent) had superficial invasion (tunica adventitia) and 47 (21·1 per cent) had deep invasion (tunica media or intima). Median survival was 18·8 months for patients who had primary closure, 27·6 months for those with an end-to-end anastomosis and 13·0 months among patients with an interposition graft. There was no significant difference in median survival between patients with superficial, deep or no histological vein involvement (20·8, 21·3 and 13·3 months respectively; P = 0·111). Venous tumour infiltration was not associated with decreased overall survival on multivariable analysis. CONCLUSION: In this study, there was no difference in morbidity between the three modes of venous reconstruction, and overall survival was similar regardless of tumour infiltration of the vein.


Asunto(s)
Adenocarcinoma/patología , Adenocarcinoma/cirugía , Invasividad Neoplásica , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/cirugía , Vena Porta/patología , Adenocarcinoma/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Anastomosis Quirúrgica , Estudios de Cohortes , Femenino , Humanos , Venas Yugulares/trasplante , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/mortalidad , Pancreaticoduodenectomía , Vena Porta/cirugía , Estudios Retrospectivos
10.
Eur J Vasc Endovasc Surg ; 53(1): 114-121, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27919609

RESUMEN

OBJECTIVES: Chronic venous disease (CVD) is common, affecting a quarter of the population. Current conservative methods of treatment aim to prevent progression of disease by reducing ambulatory venous pressure. Neuromuscular electrical stimulation (NMES) refers to the use of electrical impulses to elicit muscle contraction. This pilot randomised controlled trial investigates the effect of a footplate NMES device (REVITIVE) on venous flow parameters, limb oedema, and quality of life outcome measures in patients with CVD. METHODS: Twenty-two patients with Clinical Etiological Anatomical and Pathophysiological (CEAP) clinical class C2-C4 venous disease were randomised to receive a sham or test device. The recommended duration of use was for 30 minutes daily for 6 weeks. Venous flow parameters (duplex ultrasound), limb volume (optoelectric volumeter), and quality of life outcome measures were measured at baseline and after 6 weeks. RESULTS: The mean age of participants was 62 years, body mass index 28.6, with a 15:7 female preponderance. There was a significant difference in the percentage change in femoral vein flow parameters (from baseline) between the test and sham group while using the device (Week 0 time-averaged mean velocity 102.4% vs. -9.1%, p < .0001; volume flow 107.9% vs. -3.7%, p < .0001; peak velocity 377.7% vs. -6.7%, p < .0001). Limb volume was observed to increase significantly in the sham group (2.0% at Week 0 and 1.2% at Week 6; p < .01). This was prevented in the test group (+0.8% at Week 0 and 1.0% at Week 6; p = .06). There was a significant difference in the Aberdeen Varicose Vein Questionnaire between the two groups over the 6 weeks. CONCLUSIONS: This trial demonstrated a significant difference in venous flow parameters and prevention of orthostatic limb oedema with NMES. There was a positive effect on quality of life. Larger studies are required to determine the clinical significance of this in patients with venous disease.


Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Enfermedades Vasculares/terapia , Anciano , Enfermedad Crónica , Edema/prevención & control , Terapia por Estimulación Eléctrica/instrumentación , Femenino , Vena Femoral/fisiología , Humanos , Extremidad Inferior/irrigación sanguínea , Masculino , Persona de Mediana Edad , Contracción Muscular/fisiología , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/fisiología , Cooperación del Paciente , Proyectos Piloto , Calidad de Vida , Flujo Sanguíneo Regional
11.
Adv Exp Med Biol ; 906: 387-406, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27638628

RESUMEN

BACKGROUND: Peripheral arterial disease (PAD) is common and symptoms can be debilitating and lethal. Risk management, exercise, radiological and surgical intervention are all valuable therapies, but morbidity and mortality rates from this disease are increasing. Circulatory enhancement can be achieved using simple medical electronic devices, with claims of minimal adverse side effects. The evidence for these is variable, prompting a review of the available literature. METHODS: Embase and Medline were interrogated for full text articles in humans and written in English. Any external medical devices used in the management of peripheral arterial disease were included if they had objective outcome data. RESULTS: Thirty-one papers met inclusion criteria, but protocols were heterogenous. The medical devices reported were intermittent pneumatic compression (IPC), electronic nerve (NMES) or muscle stimulators (EMS), and galvanic electrical dressings. In patients with intermittent claudication, IPC devices increase popliteal artery velocity (49-70 %) and flow (49-84 %). Gastrocnemius EMS increased superficial femoral artery flow by 140 %. Over 4.5-6 months IPC increased intermittent claudication distance (ICD) (97-150 %) and absolute walking distance (AWD) (84-112 %), with an associated increase in quality of life. NMES of the calf increased ICD and AWD by 82 % and 61-150 % at 4 weeks, and 26 % and 34 % at 8 weeks. In patients with critical limb ischaemia IPC reduced rest pain in 40-100 % and was associated with ulcer healing rates of 26 %. IPC had an early limb salvage rate of 58-83 % at 1-3 months, and 58-94 % at 1.5-3.5 years. No studies have reported the use of EMS or NMES in the management of CLI. CONCLUSION: There is evidence to support the use of IPC in the management of claudication and CLI. There is a building body of literature to support the use of electrical stimulators in PAD, but this is low level to date. Devices may be of special benefit to those with limited exercise capacity, and in non-reconstructable critical limb ischaemia. Galvanic stimulation is not recommended.


Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Claudicación Intermitente/terapia , Aparatos de Compresión Neumática Intermitente , Enfermedad Arterial Periférica/terapia , Trombosis de la Vena/terapia , Manejo de la Enfermedad , Arteria Femoral/patología , Humanos , Claudicación Intermitente/patología , Enfermedad Arterial Periférica/patología , Calidad de Vida , Transductores de Presión , Trombosis de la Vena/patología
12.
Adv Exp Med Biol ; 906: 377-386, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27620314

RESUMEN

INTRODUCTION: The prevention and management of venous disease is a therapeutic challenge. Movement of blood through the venous system is augmented by the action of muscles on the deep veins, and can be achieved through the application of electrical current. The efficacy of currently available clinical devices for this purpose is unknown, and is investigated here. METHODS: A literature search of the EMBASE and Medline databases was performed, and studies were included if they were full text articles, written in english, pertaining to venous disease and neuromuscular electrical stimulation (NMES). RESULTS: NMES devices increase venous haemodynamic parameters such as peak velocity and volume flow. Studies report them to be non-inferior to intermittent pneumatic compression. They are effective in the prevention of venous thromboembolism, though inferior to low molecular weight heparin. NMES can reduce symptoms of chronic venous disease. DISCUSSION: NMES is an important tool in the prevention and management of venous disease, and avoids the significant risks associated with heparin administration. Data explored here is heterogenous in device, protocol, and reported end-points, therefore should be interpreted with care. Long term effects of treatment with NMES have not been explored.


Asunto(s)
Estimulación Eléctrica , Tromboembolia Venosa/terapia , Trombosis de la Vena/terapia , Hemodinámica , Heparina de Bajo-Peso-Molecular/uso terapéutico , Humanos , Músculo Liso Vascular/fisiología , Unión Neuromuscular/fisiología , Medias de Compresión , Resultado del Tratamiento , Venas/patología , Tromboembolia Venosa/patología , Tromboembolia Venosa/prevención & control , Trombosis de la Vena/patología , Trombosis de la Vena/prevención & control
13.
Med J Armed Forces India ; 73(1): 74-79, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28123249

RESUMEN

Acute appendicitis (AA) is the commonest cause of pain abdomen requiring surgical intervention. Diagnosis as well as management of acute appendicitis is mired in controversies and contradictions even today. Clinicians often face the dilemma of balancing negative appendectomy rate and perforation rate if the diagnosis is based on clinical scoring alone. Laboratory results are often non-specific. Imaging has an important role not only in diagnosing appendicitis and its complication but also suggesting alternate diagnosis in appropriate cases. However, there is no universally accepted diagnostic imaging algorithm for appendicitis. Imaging of acute appendicitis needs to be streamlined keeping pros and cons of the available investigative modalities. Radiography has practically no role today in the diagnosis and management of acute appendicitis. Ultrasonography (USG) should be the first line imaging modality for all ages, particularly for children and non-obese young adults including women of reproductive age group. If USG findings are unequivocal and correlate with clinical assessment, no further imaging is needed. In case of equivocal USG findings or clinico-radiological dissociation, follow-up/further imaging (computed tomography (CT) scan/magnetic resonance imaging (MRI)) is recommended. In pediatric and pregnant patients with inconclusive initial USG, MRI is the next option. Routine use of CT scan for diagnosis of AA needs to be discouraged. Our proposed version of a practical imaging algorithm, with USG first and always has been incorporated in the article.

14.
Med J Armed Forces India ; 73(2): 188-196, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28924323

RESUMEN

Headache disorders are among the most common presenting complaints in any neurology outpatient department. International Headache Society classifies headaches as "primary" or "secondary". The causes of secondary headaches are varied and intracranial hypotension is one of them. It typically presents clinically with postural headaches but most of the times, its diagnosis is delayed, as it is an uncommon cause and there is poor awareness among the medical fraternity about this condition. Imaging, especially magnetic resonance imaging (MRI), plays a crucial role in the diagnosis of intracranial hypotension by not only confirming the diagnosis but also detecting the cause in some cases. This case series tries to highlight the MRI findings of intracranial hypotension in three cases with different etiologies.

15.
Med J Armed Forces India ; 73(1): 88-90, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28123252

RESUMEN

Lunate dislocation is an uncommon injury occurring in young adults due to high-energy trauma. The volar displacement of the bone may result in compression of the median nerve within the carpal tunnel and is an uncommon cause of entrapment neuropathy.

16.
Med J Armed Forces India ; 73(3): 232-241, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28790780

RESUMEN

BACKGROUND: Doppler indices form an integral component of noninvasive evaluation of fetal well-being. There is paucity of information about normal obstetric Doppler indices, particularly from the Indian subcontinent. The aim of the study was to find the values of pulsatility index (PI), resistive index (RI) of umbilical artery (UA), and fetal middle cerebral artery (MCA) and calculate cerebro-placental ratio (CP ratio) for 18-40 weeks of normal gestation so that a reference range of these Doppler values can be postulated. METHODS: 200 patients were enrolled in the study for color Doppler study of UA and MCA and were serially followed up at 4-6 weeks interval for Doppler indices. Angle-independent Doppler indices like PI and RI for MCA and UA were obtained during each examination. CP ratio was calculated in each case. All the cases were followed up till delivery and the perinatal outcome was recorded. RESULTS & CONCLUSION: The fetal MCA PI and RI showed a parabolic curve with plateau at 28-30 weeks of gestation. A significant correlation was noted between MCA PI and RI with gestational age. UA PI and RI showed a gradual fall over the gestational age with a strong negative correlation. There was a significant correlation between MCA PI and UA PI with their respective RI values. CP ratio has also shown a parabolic curve with turning point at 31-32 weeks of gestation. A significant correlation was noted between CP ratio and gestational age. CP ratio also showed a minimal positive correlation with MCA PI and a strong negative correlation with UA PI.

17.
Am J Transplant ; 16(6): 1779-87, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26752191

RESUMEN

The number of donor organs suitable for liver transplantation is restricted by cold preservation and ischemia-reperfusion injury. We present the first patients transplanted using a normothermic machine perfusion (NMP) device that transports and stores an organ in a fully functioning state at 37°C. In this Phase 1 trial, organs were retrieved using standard techniques, attached to the perfusion device at the donor hospital, and transported to the implanting center in a functioning state. NMP livers were matched 1:2 to cold-stored livers. Twenty patients underwent liver transplantation after NMP. Median NMP time was 9.3 (3.5-18.5) h versus median cold ischaemia time of 8.9 (4.2-11.4) h. Thirty-day graft survival was similar (100% NMP vs. 97.5% control, p = 1.00). Median peak aspartate aminotransferase in the first 7 days was significantly lower in the NMP group (417 IU [84-4681]) versus (902 IU [218-8786], p = 0.03). This first report of liver transplantation using NMP-preserved livers demonstrates the safety and feasibility of using this technology from retrieval to transplantation, including transportation. NMP may be valuable in increasing the number of donor livers and improving the function of transplantable organs.


Asunto(s)
Hepatopatías/cirugía , Trasplante de Hígado/métodos , Preservación de Órganos/métodos , Perfusión/métodos , Recolección de Tejidos y Órganos/métodos , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Isquemia Fría , Estudios de Factibilidad , Femenino , Supervivencia de Injerto , Humanos , Trasplante de Hígado/instrumentación , Masculino , Persona de Mediana Edad , Preservación de Órganos/instrumentación , Donantes de Tejidos , Recolección de Tejidos y Órganos/instrumentación , Isquemia Tibia , Adulto Joven
18.
Med J Armed Forces India ; 72(4): 377-383, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27843187

RESUMEN

BACKGROUND: Coronary artery disease (CAD) is a common cause of morbidity and mortality worldwide. Although catheter coronary angiography (CCA) is the gold standard in the diagnosis and management of CAD, coronary CT angiography (CCTA) has shown promising results for the same. METHODS: CCTA was done using 40 slice multi-detector CT (Somatom Sensation, Siemens, Germany) machine in 220 patients of suspected CAD. Patients were classified as (a) normal (no calcific or soft plaque), (b) non-obstructive coronary disease (<50% stenosis), (c) obstructive coronary disease (>50% stenosis), or (d) a non-diagnostic study. RESULTS: 96 (43.6%) cases were found to have normal coronary arteries on CCTA, 41 (18.6%) patients were classified as having non-obstructive disease, 67 (30.5%) patients were defined to have obstructive CAD, and 16 cases (7.3%) were inconclusive. Significantly obstructive triple vessel disease was noted in 4 (6%) cases. Double vessel disease was seen in 25 (37.3%) cases and single vessel disease was seen in 38 (56.7%). Single most common vessel with obstructive CAD was left anterior descending artery and was noted in 30 (44.7%) out of 67 such cases. The least affected vessel was left circumflex in 15 cases (22.3%). Median calcium score for non-obstructive CAD was 60 (range 30-95), and for obstructive CAD 300 (range 120-780). CONCLUSION: Key benefits of CCTA lie in the avoidance of CCA since it has a high negative predictive value. CCTA has a definite role in post-stent and post-coronary artery bypass graft patients.

19.
Indian J Crit Care Med ; 20(5): 261-6, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27275073

RESUMEN

BACKGROUND: Ventilator-associated pneumonia (VAP) is a common complication with endotracheal intubation. The occurrence of VAP results in significant mortality and morbidity. Earlier studies have shown reduction in the incidence of VAP with subglottic secretion drainage. The incidence of VAP in neurologically injured patients is higher and can impact the neurological outcome. This study aimed to compare the incidence of VAP with standard endotracheal tube (SETT) and suction above cuff endotracheal tube (SACETT) in neurologically ill patients and its impact on clinical outcome. METHODS: Fifty-four patients with neurological illnesses aged ≥18 years and requiring intubation and/or ventilation and anticipated to remain on ETT for ≥48 h were randomized to receive either SETT or SACETT. All the VAP preventive measures were similar between two groups except for the difference in type of tube. RESULTS: The data of 50 patients were analyzed. The incidence of clinical VAP was 20% in SETT group and 12% in SACETT group; (P = 0.70). The incidence of microbiological VAP was higher in the SETT group (52%) as compared to SACETT group (44%) but not statistically significant; (P = 0.78). There was no difference between the two groups for measured outcomes such as duration of intubation, mechanical ventilation, and Intensive Care Unit stay. CONCLUSIONS: In this pilot study in neurological population, a there was no significant difference in incidence of clinical and microbiological VAP was seen between SETT and SACETT, when other strategies for VAP prevention were similar. Other outcomes were similar with use of either tube for intubation.

20.
Med J Armed Forces India ; 72(3): 285-92, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27546971

RESUMEN

Acute appendicitis (AA) is a common surgical emergency. Accurate and timely diagnosis of AA is essential for successful outcome. Imaging plays an important role in the diagnosis, exclusion of AA as well as diagnosing alternative clinical conditions which can closely simulate AA. A correct alterative diagnosis may obviate the need of unnecessary appendectomy or may even change the treatment regime altogether. This pictorial essay illustrates various clinical conditions which mimicked AA clinically during our day to day practice.

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