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1.
J Nat Prod ; 87(9): 2302-2309, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39196851

RESUMEN

Imported fire ants are significant agricultural pests. Repellents can be used to prevent foraging fire ants from entering sensitive areas, including electrical equipment, nursing homes, and hospitals. Bioassay-guided fractionation of the essential oil extracted from gurjun balsam (Dipterocarpus turbinatus) resulted in the identification of (-)-α-copaene (1) as the repellent constituent with a minimum repellent effective dose (MRED) of 15.6 µg/g against both red imported fire ants (Solenopsis invicta) and hybrid imported fire ants (Solenopsis invicta × Solenopsis richteri). Stereoselective oxidation of 1 via autoxidation and chemical methods produced (-)-5R-hydroperoxy-α-copaene (2), (+)-3S-hydroperoxycopa-4-ene (3), (-)-α-copaene oxide (4), (+)-ß-copaen-4α-ol (5), copaenediol (6), and copaene ketol (7). Reduction of 2 and 3 with triphenylphosphine afforded (-)-5R-hydroxy-α-copaene (2a) and (+)-3S-hydroxycopa-4-ene (3a), respectively, which led to the structural revision of copa-3-en-2α-ol and copa-2-en-4-ol as 2a and 3, respectively. The configurational assignment of compound 4 in the literature was also clarified by the detailed analysis of 2D NMR spectroscopic data. Compounds 2-7 showed repellency with MREDs ranging from 3.9 to 15.6 µg/g against hybrid and red imported fire ants, indicating that chemical modification can enhance the repellent effect of (-)-α-copaene.


Asunto(s)
Hormigas , Repelentes de Insectos , Aceites Volátiles , Oxidación-Reducción , Sesquiterpenos , Hormigas/efectos de los fármacos , Repelentes de Insectos/farmacología , Repelentes de Insectos/química , Animales , Sesquiterpenos/química , Sesquiterpenos/farmacología , Estereoisomerismo , Aceites Volátiles/química , Aceites Volátiles/farmacología , Estructura Molecular , Hormigas de Fuego
2.
Bull Entomol Res ; 114(2): 244-253, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38444240

RESUMEN

Since metabolism, survival, and reproduction in hexapods are closely related to temperatures; changes in the mean and variance of temperature are major aspects of global climate change. In the typical context of biological control, understanding how predator-prey systems are impacted under thermal conditions can make pest control more effective and resilient. With this view, this study investigated temperature-mediated development and predation parameters of the predator Harmonia axyridis against the potential prey Spodoptera litura. The age-stage, two-sex life table of the predator was constructed at four temperatures (i.e. 15, 20, 25, and 30°C) by feeding on the first instar larvae of S. litura. Our results showed that the mean generation time (T) decreased but the intrinsic rate of increase (r) and the finite rate of increase (λ) increased with increased temperature. The mean duration of the total preadult stage decreased with higher temperatures. The T and r were 70.47 d and 0.0769 d-1 at 15°C; 58.41 d and 0.0958 d-1 at 20°C; 38.71 d and 0.1526 d-1 at 25°C; and 29.59 d and 0.1822 d-1 at 30°C, respectively. The highest net reproductive rate (R0) and fecundity were obtained at 25°C. The highest λ (1.1998 d-1) and lowest T (29.59 d) were obtained at 30°C, whereas the maximum net predation rate (C0) was at 25°C. Total population and predation rates projections were the highest at 30°C. Based on these findings, we anticipate that biological control strategies for this predator release against S. litura should be attuned to warming scenarios to achieve better biocontrol functions.


Asunto(s)
Escarabajos , Larva , Control Biológico de Vectores , Conducta Predatoria , Reproducción , Spodoptera , Temperatura , Animales , Spodoptera/fisiología , Spodoptera/crecimiento & desarrollo , Larva/crecimiento & desarrollo , Larva/fisiología , Escarabajos/fisiología , Escarabajos/crecimiento & desarrollo , Femenino , Masculino
3.
J Anat ; 243(1): 39-50, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36914412

RESUMEN

The middle ear muscles have vital roles, yet their precise function in hearing and protection remains unclear. To better understand the function of these muscles in humans, the morphology, fiber composition, and metabolic properties of nine tensor tympani and eight stapedius muscles were analyzed with immunohistochemical, enzyme-histochemical, biochemical, and morphometric techniques. Human orofacial, jaw, extraocular, and limb muscles were used as references. The immunohistochemical analysis showed that the stapedius and tensor tympani muscles were markedly dominated by fibers expressing fast contracting myosin heavy chain MyHC-2A and MyHC-2X (79 ± 6% vs. 86 ± 9%, respectively, p = 0.04). In fact, the middle ear muscles had one of the highest proportions of MyHC-2 fibers ever reported for human muscles. Interestingly, the biochemical analysis revealed a MyHC isoform of unknown identity in both the stapedius and tensor tympani muscles. Muscle fibers containing two or more MyHC isoforms were relatively frequently observed in both muscles. A proportion of these hybrid fibers expressed a developmental MyHC isoform that is normally absent in adult human limb muscles. The middle ear muscles differed from orofacial, jaw, and limb muscles by having significantly smaller fibers (220 vs. 360 µm2 , respectively) and significantly higher variability in fiber size, capillarization per fiber area, mitochondrial oxidative activity, and density of nerve fascicles. Muscle spindles were observed in the tensor tympani muscle but not in the stapedius muscle. We conclude that the middle ear muscles have a highly specialized muscle morphology, fiber composition, and metabolic properties that generally showed more similarities to orofacial than jaw and limb muscles. Although the muscle fiber characteristics in the tensor tympani and stapedius muscles suggest a capacity for fast, fine-tuned, and sustainable contractions, their difference in proprioceptive control reflects different functions in hearing and protection of the inner ear.


Asunto(s)
Cadenas Pesadas de Miosina , Estapedio , Tensor del Tímpano , Humanos , Estapedio/química , Estapedio/metabolismo , Tensor del Tímpano/metabolismo , Oído Medio , Cadenas Pesadas de Miosina/metabolismo , Mitocondrias , Fenotipo , Isoformas de Proteínas
4.
Bull Entomol Res ; 113(4): 565-573, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37434448

RESUMEN

Arthropod species diversity enhances ecosystem productivity and sustainability by increasing pollination and biological control services. Although, it is declining rapidly due to conventional agricultural intensification, organic agriculture with reduced reliance on agronomic inputs can regenerate ecosystems' resilience and restore them. Here, we report whether hexapod communities differ on both types of farming systems in small-scale field plot experiments, wherein Maize variety AG-589 was grown organically and conventionally in the 2020 and 2021 seasons. Livestock manure was applied in organic fields, whereas nitrogen and phosphorous were used as synthetic fertilizers in conventional fields. Hexapods were sampled three weeks after sowing once a week from the middle rows of subplots from both organically and conventionally grown maize. Twelve species of herbivores and four species of predators were recorded. Hexapod abundance overall and that of herbivores only was higher in conventionally cultivated maize, while predator abundance was higher in organic maize. Herbivores species diversity and evenness were significantly higher in conventional maize. Predator species diversity and evenness were significantly higher in organic maize fields. We noted predator abundance, diversity, and evenness as strong predictors to lower herbivore populations. These findings suggest that organic farming conserves natural enemies' biodiversity and regulates herbivores with increased provision of suitable habitats and prey resources for natural enemies, leading to enhanced relative abundance in their specialized niches. Thus, organic agriculture can potentially mediate better ecosystem services.


Asunto(s)
Artrópodos , Ecosistema , Animales , Agricultura Orgánica , Zea mays , Insectos , Biodiversidad , Agricultura
5.
Molecules ; 28(14)2023 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-37513455

RESUMEN

Matricaria chamomilla flower essential oils (EOs) blue Egyptian (EO-1), chamomile German CO2 (EO-2), and chamomile German (EO-3) and the pure compound α-bisabolol were evaluated against red imported fire ants (RIFA), Solenopsis invicta Buren, black imported fire ants, S. richteri Forel (BIFA), and hybrid imported fire ants (HIFA) for their repellency and toxicity. A series of serial dilutions were tested starting from 125 µg/g until the failure of the treatment. Based on the amount of sand removed, EO-1 showed significant repellency at dosages of 7.8, 7.8, and 31.25 µg/g against RIFA, BIFA, and HIFA, respectively. EO-3 was repellent at 3.9, 7.8, and 31.25 µg/g against BIFA, RIFA, and HIFA, whereas α-bisabolol was active at 7.8, 7.8, and 31.25 µg/g against BIFA, HIFA, and RIFA, respectively. DEET (N, N-diethyl-meta-toluamide) was active at 31.25 µg/g. Toxicity of EOs and α-bisabolol was mild to moderate. For EO-1, LC50 values were 93.6 and 188.11 µg/g against RIFA and BIFA; 98.11 and 138.4 µg/g for EO-2; and 142.92 and 202.49 µg/g for EO-3, respectively. The LC50 of α-bisabolol was 159.23 µg/g against RIFA. In conclusion, M. chamomilla EOs and α-bisabolol offer great potential to be developed as imported fire ant repellents.


Asunto(s)
Hormigas , Repelentes de Insectos , Matricaria , Aceites Volátiles , Animales , Aceites Volátiles/farmacología , Sesquiterpenos Monocíclicos , Repelentes de Insectos/farmacología
6.
Molecules ; 28(16)2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37630353

RESUMEN

The U.S. Department of Agriculture (USDA) has established research programs to fight the phytopathogen Colletotrichum fragariae and the invasive red imported fire ant, Solenopsis invicta. C. fragariae is known to cause anthracnose disease in fruits and vegetables, while S. invicta is known for its aggressive behavior and painful stings and for being the cause of significant damage to crops, as well as harm to humans and animals. Many plants have been studied for potential activity against C. fragariae and S. invicta. Among the studied plants, Houttuynia cordata Thunb has been shown to contain 2-undecanone, which h is known for its antifungal activity against Colletotrichum gloesporioides. Based on the mean amount of sand removed, 2-undecanone showed significant repellency at 62.5 µg/g, similar to DEET (N,N-diethyl-meta-toluamide), against S. invicta. The 2-Undecanone with an LC50 of 44.59 µg/g showed toxicity against S. invicta workers. However, neither H. cordata extract nor 2-undecanone had shown activity against C. fragariae despite their known activity against C. gloesporioides, which in turn motivates us in repositioning 2-undecanone as a selected candidate for a Claisen-Schmidt condensation that enables access to several analogs (2a-f). Among the prepared analogs, (E)-1-(3-methylbenzo[b]thiophen-2-yl)dodec-1-en-3-one (2b) and (E)-1-(5-bromothiophen-2-yl)dodec-1-en-3-one (2f) showed promising activity against C. fragariae, revealing a distinctive structural activity relationship (SAR). The generated analogs revealed a clear regioselectivity pattern through forming the C=C alkene bond at position C-1. These data open the window for further lead optimization and product development in the context of managing C. fragariae and S. invicta.


Asunto(s)
Hormigas , Colletotrichum , Fungicidas Industriales , Houttuynia , Repelentes de Insectos , Insecticidas , Animales , Humanos , Repelentes de Insectos/farmacología
7.
Respir Res ; 20(1): 31, 2019 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-30764835

RESUMEN

BACKGROUND: The pathophysiology of obstruction and swallowing dysfunction in snores and sleep apnea patients remains unclear. Neuropathy and to some extent myopathy have been suggested as contributing causes. Recently we reported an absence and an abnormal isoform of two cytoskeletal proteins, desmin, and dystrophin, in upper airway muscles of healthy humans. These cytoskeletal proteins are considered vital for muscle function. We aimed to investigate for muscle cytoskeletal abnormalities in upper airways and its association with swallowing dysfunction and severity of sleep apnea. METHODS: Cytoskeletal proteins desmin and dystrophin were morphologically evaluated in the uvula muscle of 22 patients undergoing soft palate surgery due to snoring and sleep apnea and in 10 healthy controls. The muscles were analysed with immunohistochemical methods, and swallowing function was assessed using videoradiography. RESULTS: Desmin displayed a disorganized pattern in 21 ± 13% of the muscle fibres in patients, while these fibers were not present in controls. Muscle fibres lacking desmin were present in both patients and controls, but the proportion was higher in patients (25 ± 12% vs. 14 ± 7%, p = 0.009). The overall desmin abnormalities were significantly more frequent in patients than in controls (46 ± 18% vs. 14 ± 7%, p < 0.001). In patients, the C-terminus of the dystrophin molecule was absent in 19 ± 18% of the desmin-abnormal muscle fibres. Patients with swallowing dysfunction had 55 ± 10% desmin-abnormal muscle fibres vs. 22 ± 6% in patients without swallowing dysfunction, p = 0.002. CONCLUSION: Cytoskeletal abnormalities in soft palate muscles most likely contribute to pharyngeal dysfunction in snorers and sleep apnea patients. Plausible causes for the presence of these abnormalities is traumatic snoring vibrations, tissue stretch or muscle overload.


Asunto(s)
Desmina/metabolismo , Distrofina/metabolismo , Músculos Respiratorios/metabolismo , Síndromes de la Apnea del Sueño/metabolismo , Ronquido/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Citoesqueleto/patología , Trastornos de Deglución/metabolismo , Trastornos de Deglución/patología , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Fibras Musculares de Contracción Rápida/metabolismo , Fibras Musculares de Contracción Rápida/patología , Fibras Musculares de Contracción Lenta/metabolismo , Fibras Musculares de Contracción Lenta/patología , Paladar Blando/metabolismo , Paladar Blando/patología , Músculos Respiratorios/patología , Síndromes de la Apnea del Sueño/patología , Ronquido/patología , Úvula/metabolismo , Úvula/patología , Adulto Joven
8.
Des Monomers Polym ; 20(1): 18-32, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29491776

RESUMEN

In the present work, antibiotic drug gentamicin sulfate (GS) has been loaded into alginate dialdehyde-crosslinked casein (CAS) films for wound dressing applications. The films have been characterized by Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy. The dynamic release of model drug GS has been investigated in the physiological fluid at 37 °C. The drug release data has been interpreted in the terms of various kinetic models such as Power function model, first order model and Schott model. The release data was found to be well fitted by Schott model. The various diffusion coefficients are also evaluated. The adsorption of model therapeutic protein BSA on the film has been investigated. The maximum adsorption is found to be 5.7 mg/cm2.The films were tested for their antibacterial and anti-fungal action. Finally, the in vivo wound healing study was carried out on Albino wistar rats.

9.
J Anat ; 228(3): 487-94, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26597319

RESUMEN

The human oropharyngeal muscles have a unique anatomy with diverse and intricate functions. To investigate if this specialization is also reflected in the cytoarchitecture of muscle fibers, intermediate filament proteins and the dystrophin-associated protein complex have been analyzed in two human palate muscles, musculus uvula (UV) and musculus palatopharyngeus (PP), with immunohistochenmical and morphological techniques. Human limb muscles were used as reference. The findings show that the soft palate muscle fibers have a cytoskeletal architecture that differs from the limb muscles. While all limb muscles showed immunoreaction for a panel of antibodies directed against different domains of cytoskeletal proteins desmin and dystrophin, a subpopulation of palate muscle fibers lacked or had a faint immunoreaction for desmin (UV 11.7% and PP 9.8%) and the C-terminal of the dystrophin molecule (UV 4.2% and PP 6.4%). The vast majority of these fibers expressed slow contractile protein myosin heavy chain I. Furthermore, an unusual staining pattern was also observed in these fibers for ß-dystroglycan, caveolin-3 and neuronal nitric oxide synthase nNOS, which are all membrane-linking proteins associated with the dystrophin C-terminus. While the immunoreaction for nNOS was generally weak or absent, ß-dystroglycan and caveolin-3 showed a stronger immunostaining. The absence or a low expression of cytoskeletal proteins otherwise considered ubiquitous and important for integration and contraction of muscle cells indicate a unique cytoarchitecture designed to meet the intricate demands of the upper airway muscles. It can be concluded that a subgroup of muscle fibers in the human soft palate appears to have special biomechanical properties, and their unique cytoarchitecture must be taken into account while assessing function and pathology in oropharyngeal muscles.


Asunto(s)
Citoesqueleto/metabolismo , Músculo Esquelético/metabolismo , Paladar Blando/metabolismo , Anciano , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad
10.
Eur J Med Res ; 29(1): 216, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38566246

RESUMEN

BACKGROUND: Desmin is a major cytoskeletal protein considered ubiquitous in mature muscle fibers. However, we earlier reported that a subgroup of muscle fibers in the soft palate of healthy subjects and obstructive sleep apnea patients (OSA) lacked immunoexpression for desmin. This raised the question of whether these fibers also lack messenger ribonucleic acid (mRNA) for desmin and can be considered a novel fiber phenotype. Moreover, some fibers in the OSA patients had an abnormal distribution and aggregates of desmin. Thus, the aim of the study was to investigate if these desmin protein abnormalities are also reflected in the expression of desmin mRNA in an upper airway muscle of healthy subjects and OSA patients. METHODS: Muscle biopsies from the musculus uvulae in the soft palate were obtained from ten healthy male subjects and six male patients with OSA. Overnight sleep apnea registrations were done for all participants. Immunohistochemistry, in-situ hybridization, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) techniques were used to evaluate the presence of desmin protein and its mRNA. RESULTS: Our findings demonstrated that a group of muscle fibers lacked expression for desmin mRNA and desmin protein in healthy individuals and OSA patients (12.0 ± 5.6% vs. 23.1 ± 10.8%, p = 0.03). A subpopulation of these fibers displayed a weak subsarcolemmal rim of desmin accompanied by a few scattered mRNA dots in the cytoplasm. The muscles of OSA patients also differed from healthy subjects by exhibiting muscle fibers with reorganized or accumulated aggregates of desmin protein (14.5 ± 6.5%). In these abnormal fibers, the density of mRNA was generally low or concentrated in specific regions. The overall quantification of desmin mRNA by RT-qPCR was significantly upregulated in OSA patients compared to healthy subjects (p = 0.01). CONCLUSIONS: Our study shows evidence that muscle fibers in the human soft palate lack both mRNA and protein for desmin. This indicates a novel cytoskeletal structure and challenges the ubiquity of desmin in muscle fibers. Moreover, the observation of reorganized or accumulated aggregates of desmin mRNA and desmin protein in OSA patients suggests a disturbance in the transcription and translation process in the fibers of the patients.


Asunto(s)
Síndromes de la Apnea del Sueño , Apnea Obstructiva del Sueño , Humanos , Masculino , Desmina/genética , Apnea Obstructiva del Sueño/genética , ARN Mensajero/genética , Expresión Génica
11.
J Med Entomol ; 61(1): 191-200, 2024 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-37983140

RESUMEN

Curcuma longa L. (Zingiberales: Zingiberaceae) leaf and rhizome essential oils were evaluated for their toxicity and repellency against invasive fire ants: red imported fire ants (RIFA), Solenopsis invicta Buren, black imported fire ants (BIFA), Solenopsis richteri Forel, and a reproductively functional hybrid (HIFA). Ar-turmerone was the major constituent of leaf (42.4%) and rhizome (40.4%) essential oils. A range of concentrations starting from 156 µg/g until the failure of treatment were used. Removal of treated sand in digging bioassay was used as a criterion for repellency. Leaf essential oil showed significantly higher repellency at concentrations of 19.5, 9.8, and 4.9 µg/g against RIFA, BIFA, and HIFA workers, respectively, as compared with control whereas rhizome essential oil was active at 39, 19.5, and 4.9 µg/g against BIFA, RIFA, and HIFA, respectively. Ar-turmerone exhibited repellency at 19.5 µg/g against HIFA workers whereas DEET (N,N-diethyl-meta-toluamide) failed at 39 µg/g. Leaf essential oil showed LC50 values of 85.8, 97.7, and 182.7µg/g against RIFA, BIFA and HIFA workers, whereas the rhizome essential oil had LC50 values of 127, 109.9, and 151.2 µg/g against these species, respectively. Ar-turmerone, tested only against HIFA, with LC50 value of 57.2 was the most active compound. Bifenthrin, a commonly used pyrethroid, with LC50 of 0.03, 0.32, and 0.018 µg/g was toxic against RIFA, BIFA, and HIFA workers, respectively. Both the essential oils and ar-turmerone showed toxicity and repellency against imported fire ants. Different formulations of these natural products will be tested to explore the use potential of these natural products under field conditions.


Asunto(s)
Hormigas , Repelentes de Insectos , Insecticidas , Cetonas , Aceites Volátiles , Sesquiterpenos , Animales , Aceites Volátiles/farmacología , Hormigas de Fuego , Curcuma , Repelentes de Insectos/farmacología
12.
Insects ; 14(10)2023 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-37887802

RESUMEN

In the United States, imported fire ants are commonly referred to as red imported fire ants (Solenopsis invicta Buren), black imported fire ants (S. richteri Forel), and hybrid imported fire ants (S. invicta × S. richteri). They are significant pests, and their control heavily relies on synthetic insecticides. The extensive use of insecticides has led to public concern about their potential negative effects on human health and the well-being of wildlife and the environment. As an alternative, plant-derived natural compounds, particularly essential oils (EOs) and their main constituents, show promise as safe and environmentally friendly products for controlling fire ants. Repellants are useful in managing fire ants, and plant-derived natural repellants may serve as a safer and more environmentally friendly option. This study investigates the repellency of EO-derived compounds carvacrol, thymol, and their acetates against imported fire ant workers. The results revealed that carvacrol, a GRAS compound (Generally Recognized As Safe), was the most potent repellent against S. invicta, S. richteri, and their hybrid, with minimum repellent effective doses (MREDs) of 0.98 µg/g, 7.80 µg/g, and 0.98 µg/g, respectively. Thymol also exhibited strong repellency, with MREDs of 31.25 µg/g, 31.25 µg/g, and 7.8 µg/g, respectively. Furthermore, thyme-red essential oil, characterized by a thymol chemotype containing 48.8% thymol and 5.1% carvacrol, was found to effectively repel the hybrid ants with an MRED of 15.6 µg/g. In contrast, thyme essential oil, characterized by a linalool chemotype lacking thymol and carvacrol, did not exhibit any repellent effect, even at the highest tested dose of 125 µg/g. This study provides the first evidence of the potent repellency of carvacrol and thymol against imported fire ant workers, indicating their potential as promising repellents for fire ant control.

13.
J Xenobiot ; 13(4): 641-652, 2023 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-37987442

RESUMEN

Essential oils from five Baccharis species were screened for their toxicity and biting deterrence/repellency against yellow fever mosquito, Aedes aegypti (L.), and imported fire ants, including Solenopsis invicta Buren (RIFA), Solenopsis richteri Forel (BIFA) and their hybrids (HIFA). Baccharis microdonta DC. and B. punctulata DC. at 10 µg/cm2 showed biting deterrence similar to DEET, N, N-diethyl-meta-toluamide at 25 nmol/cm2, whereas the repellency of B. pauciflosculosa DC., B. sphenophylla Dusén ex Malme and B. reticularioides Deble & A.S. Oliveira essential oils was significantly lower than DEET against mosquitoes. Two major compounds from the active essential oils, kongol and spathulenol, also exhibited biting deterrence similar to DEET against mosquitoes. The highest toxicity exhibited against mosquitoes was by Baccharis punctulata essential oil (LC50 = 20.4 ppm), followed by B. pauciflosculosa (LC50 = 31.9 ppm), B. sphenophylla (LC50 = 30.8 ppm), B. microdonta (LC50 = 28.6 ppm), kongol (LC50 = 32.3 ppm), spathulenol (LC50 = 48.7 ppm) and B. reticularioides essential oil (LC50 = 84.4 ppm). Baccharis microdonta essential oil showed repellency against RIFA, BIFA and HIFA at 4.9, 4.9 and 39 µg/g, respectively. Baccharis microdonta essential oil also showed toxicity with LC50 of 78.9, 97.5 and 136.5 µg/g against RIFA, BIFA and HIFA, respectively, at 24 h post treatment.

14.
PLoS One ; 18(11): e0294775, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38015916

RESUMEN

Synthetic insecticides heavily applied to manage agricultural pests are highly hazardous to the environment and non-target organisms. Their overuse through repeated treatments in smallholder farming communities is frequent. Botanical biopesticides are ideal for sustainable pest management in agricultural environments by keeping synthetic insecticide use at a minimum. Here we evaluated a locally prepared neem seed extract (NSE) alongside emamectin benzoate against both lepidopteran pests Helicoverpa armigera (Hübner) and Spodoptera exigua (Hübner) on tomato Lycopersicon esculentum Mill under natural field conditions in Pakistan. We compared pest severity, fruit injury, quality, marketability, and cost:benefit ratio (CBR) between treatments. The concentration of azadirachtin A in the NSE was 26.5 ppm. NSE at 2% (20 mL/L) and the emamectin benzoate at the recommended field rate in Pakistan were sprayed weekly throughout the fruiting stage. The pest larvae were significantly more abundant on fruits than on flowers and leaves. Fruit injury and losses were significantly more important in untreated control compared to NSE and emamectin benzoate treatments. NSE efficacy varied with respect to the cultivars used and the seasons. Cultivar Eden harboured more pests than Adventa, and emamectin benzoate suppressed more pest individuals than NSE. Both the insecticidal treatments were comparable in terms of marketable yield productions as well as unmarketable, uninjured, and recovered fruit yields. NSE generated a higher CBR (1: 9.26) than emamectin benzoate (1: 3.23). NSE suppressed pests by acting as an antifeedant, similar to its synthetic counterpart. Smallholder growers can thus use NSE as a cost-effective solution in tomato pest management in Pakistan.


Asunto(s)
Insecticidas , Solanum lycopersicum , Humanos , Animales , Agentes de Control Biológico , Agricultores , Análisis Costo-Beneficio , Países en Desarrollo , Insecticidas/farmacología , Control de Plagas , Larva
15.
Laryngoscope Investig Otolaryngol ; 7(2): 636-645, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35434344

RESUMEN

Objective: Previous reports of muscle changes in the upper airways of obstructive sleep apnea (OSA) patients have primarily been attributed to acquired nerve lesions due to snoring vibrations. The aim of this study was to investigate whether alterations reflecting muscle fiber injuries also occur in the upper respiratory tract of snoring and OSA patients and if these changes relate to upper airway dysfunction. Methods: Muscle changes in biopsies from the soft palate of 20 patients suffering from snoring and OSA were investigated with enzyme, immunohistochemical, and morphometric techniques. Biopsies from eight healthy non-snoring subjects were used as controls. Swallowing dysfunction was assessed with videoradiography. Results: Fourteen patients had various degrees of swallowing dysfunction. The muscle samples from all the patients showed changes typical for both motor-nerve lesions and muscle fiber injuries. The most common alterations reflecting myopathy were fibers having aggregates and disorganization of cytoskeletal proteins (15.5 ± 10.7%). Other changes were fibers with vacuole-like structures (5.0 ± 4.4%), centrally positioned myonuclei (7.9 ± 4.8%), subsarcolemmal accumulations of nuclei, and various forms and sizes of ring fibers, that is, fibers where the myofilaments were disorganized peripherally (2.8 ± 2.8%). Conclusion: The results show that muscle changes mirroring both myopathy and neuropathy co-exist in the upper airway of snoring OSA patients. These findings suggest muscle weakness as a contributing factor to the upper airway dysfunction in OSA patients.

16.
Sci Rep ; 12(1): 15303, 2022 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-36096905

RESUMEN

Biological control is one of the strategies of pest control which is determined by the biological fitness and metabolic rates of the predator species used. Temperature and resource are important factors which influence the role of insects as biocontrol agents. Harmonia axyridis is a cosmopolitan and non-specific polyphagous predator. It can survive ecologically diverse environments and exploit multiple preys. This study investigated the effects of temperature on the population parameters of H. axyridis and its predation on the eggs of prey Spodoptera litura. For this purpose, an age-stage, two-sex life table of the predator was constructed at four constant temperatures, i.e. 15, 20, 25 and 30 °C, under laboratory settings of: 70 ± 5% RH, and 16:8 h (L: D) photoperiod. A computer simulation was then used to project the population and predation responses with respect to temperatures tested. We found that the development of larvae and adult (male/female) stages of H. axyridis decreased with colder temperatures (i.e., 15 and 20 °C) but increased with warmer temperatures (25 and 30 °C). The intrinsic rate of increase (r) and mean generation time (T) were 0.0662 d-1 and 79.84 d at 15 °C, 0.0843 d-1 and 64.90 d at 20 °C, 0.1067 d-1 and 48.89 d at 25 °C, and 0.1378 d-1 and 35.55 d at 30 °C, respectively. The mean duration of the total pre-adult stage was 44.26, 32.91, 20.63, and 15.39 d at 15, 20, 25, and 30 °C, respectively. At 30 °C. the finite rate of increase (1.1477 d-1) was the highest and the mean generation time (35.55 d) was the shortest. The net predation rate (C0) was 7935.54, 10,466.28, 10,139.38, and 7126.36 eggs at 15, 20, 25, and 30 °C, respectively. Population and predation projections were proportional to temperature. These findings are important for modelling the population responses of H. axyridis to climate change and tailoring integrated pest management strategies to altered climates.


Asunto(s)
Escarabajos , Conducta Predatoria , Animales , Escarabajos/fisiología , Simulación por Computador , Femenino , Estadios del Ciclo de Vida , Masculino , Spodoptera/fisiología , Temperatura
17.
Front Plant Sci ; 13: 849574, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35845680

RESUMEN

Functional responses are central to predator-prey dynamics and describe how predation varies with prey abundance. Functional responses often are measured without regard to prey size (i.e., body mass) or the temperature dependence of feeding rates. However, variation in prey size within populations is ubiquitous, and predation rates are often both size and temperature-dependent. Here, we assessed functional responses of larvae and adult Harmonia axyridis on the 1st, 2nd, and 3rd instars of the prey Spodoptera litura across a range of temperatures (i.e., 15, 20, 25, 30, and 35°C). The type and parameters of the functional responses were determined using logistic regression and fitted to the Roger's random predator equation. The magnitude of predation varied with the predator and prey stage, but prey predation increased with warming and predator age. Predation by the female and 4th instar of H. axyridis on the 1st instar of prey was greater, followed by the 2nd and 3rd instar of prey S. litura. No predation occurred on the larger prey for the 1st, 2nd, and 3rd instars of H. axyridis. The larvae and adult H. axyridis produced a type II (hyperbolic) functional response curve across all temperatures and the three prey types they consumed. Space clearance rates, handling time, and maximum predation rates of H. axyridis changed with temperature and prey size, increasing with temperature and decreasing with prey size, suggesting more predation will occur on younger prey. This study indicates an interactive role of temperature and prey/predator size in shaping functional responses, which might complicate the planning of effective biocontrol strategies against this serious pest.

18.
Cureus ; 13(1): e12524, 2021 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-33564528

RESUMEN

We present a case of chronic total occlusion (CTO) in a functional 79-year-old female with no past history of coronary artery disease, who was previously asymptomatic due to robust collateral circulation. A 79-year-old Caucasian female presented to the emergency department complaining of chest pain radiating to the neck, jaw, left arm with associated numbness in the left fingers, that had started earlier in the day. She has no previous cardiac history and never had similar symptoms before. Troponin levels were negative. Nuclear stress test showed findings worrisome for ischemia and was a high-risk exam. The patient underwent diagnostic angiography. There was complete total occlusion of the mid right coronary artery, with collateral circulation supplying the distal right coronary artery territory. Ultimately, it found that progressive stenosis of the left anterior descending (LAD) artery led to inadequate collateral circulation and completely occluded the right coronary artery's territory, causing the patient's new-onset angina. Afterwards, the patient underwent percutaneous coronary intervention (PCI). Successful implantation of two drug-eluting stents occurred. The final angiographic result was 0% residual stenosis and Thrombolysis in Myocardial Infarction (TIMI)-3 flow. CTO affecting one or more coronary arteries is not uncommon in patients taken to the catheterization laboratory. However, despite recent advancements in PCI outcomes, treatment of CTO by PCI remains relatively low, due to fear of adverse outcomes such as cardiac perforations. Recent research has supported the safety of performing PCIs on patients with CTO. This case report further reinforces the need to approach treating CTO via angioplasty.

19.
Cureus ; 13(1): e12901, 2021 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-33654586

RESUMEN

We present a unique case of a satellite pleural-based thymoma. The patient is a 66-year-old Caucasian female with a history of a left pericardial soft tissue mass. She had been asymptomatic. Chest radiograph incidentally revealed an acute increase in the size of the mass. CT scan identified a 5.6 X 5.2 X 4.2 cm mediastinal mass in the left infrahilar region along the left lateral pericardium. Positron emission tomography (PET) scan showed the mass had an increased F18 FDG uptake with standardized uptake value (SUV) of 7.2. Left thoracotomy resected a 81g, 6 X 5.5 X 5.0 cm tan-pink well-encapsulated pedunculated mass displacing the left phrenic nerve. The mass was under the parietal pleura and not attached to the pericardium. Immunohistochemical profile identified the tumor as a thymoma, B1 type. Thymomas are relatively rare in the United States, pleural-based thymomas even more so. Early detection of thymomas is critical to avoid late-stage growths. Pericardial involvement of thymomas increases risk of pericardial effusion, tamponade and a complicated thymectomy. Pleural-based thymomas can result in diaphragmatic paralysis secondary to phrenic nerve involvement.

20.
Cureus ; 13(3): e13742, 2021 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-33842120

RESUMEN

Limited scleroderma falls under the umbrella of systemic sclerosis, an autoimmune disease that presents with multiorgan dysfunction that includes pulmonary arterial hypertension. We examine a case of pulmonary arterial hypertension in an elderly nonsmoker with a history of limited scleroderma.  The patient presented with abdominal tenderness and was diagnosed with a sigmoid colonic stricture. She underwent laparoscopic bowel resection. During and after her surgery, she suffered from worsening respiratory function and decompensated, developing a large pleural effusion that led to a thoracentesis and a prolonged hospital course. Patients with scleroderma can develop acute symptoms involving several organ systems, including the colonic tract and lungs, as seen in our patient. A thorough workup and continuous close management and monitoring are necessary to avoid further complications in these patients, especially in the postoperative period.

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