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1.
Microsurgery ; 44(4): e31169, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38549425

RESUMO

BACKGROUND: It is important to include as many perforators as possible in order to enhance the vascularity of a deep inferior epigastric perforator (DIEP) flap. However, the rectus muscle must be transected transversely, which prevents suturing and can cause a defect along the same line as the muscle-sparing procedure. When harvesting the DIEP flap, no specific method was suggested to solve these muscle defects. We found that by transecting the rectus muscle transversely, the muscle could be sutured in the tendinous area more easily while maintaining muscle function. The purpose of this study is to confirm the long-term recovery of the rectus abdominis muscle through the volume change after DIEP flap using this tendinous transection and suture method. PATIENTS AND METHODS: A retrospective review of 28 patients who underwent unilateral breast reconstruction using a DIEP flap and the tendinous transection method for multiple perforators between May 2018 and April 2020 was conducted. The preoperative and postoperative volumes of the rectus abdominis muscle were estimated both the harvest and opposite sides. RESULTS: The preoperative and postoperative muscle volumes from the harvest side were 50.08 ± 8.71 cm3 and 48.56 ± 8.61 cm3, respectively. The volume difference was 1.522 cm3 decrease, which was not statistically significant (p = .070). The preoperative and postoperative muscle volumes from the opposite side were 50.50 ± 8.15 cm3 and 50.08 ± 8.18 cm3, respectively. The volume difference was 0.434 cm3 increase and was not statistically significant (p = .064). Postoperative volume changes in the rectus muscle were not statistically significant on either side. CONCLUSION: The tendinous transection method in the DIEP flap procedure did not significantly affect postoperative rectus muscle volume. Therefore, we expect this harvest method to allow DIEP flap reconstruction that includes multiple perforators and complete donor muscle recovery.


Assuntos
Mamoplastia , Retalho Perfurante , Humanos , Retalho Perfurante/cirurgia , Reto do Abdome/transplante , Mamoplastia/métodos , Estudos Retrospectivos , Músculos/cirurgia , Artérias Epigástricas/cirurgia , Complicações Pós-Operatórias/etiologia
2.
J Craniofac Surg ; 33(5): e541-e544, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36041133

RESUMO

Giant lipomas are uncommon in the neck or craniofacial region. A 55-year-old male presented with a large pendulous mass arising from the dorsal aspect of his neck, which he had known about for 20 years. Discomfort during sleeping, frequent headaches, and chronic neck pain were his chief complaints. Computed topography revealed a well-circumscribed lipomatous lesion. A decrease in cervical spine lordosis was noted on sagittal x-rays. Surgical excision with local flap coverage was performed. The specimen weighed 2800 g. The patient reported immediate resolution of neck pain, and complete resolution of headaches following surgery. An increase in the degree of lordosis was seen in sagittal x-rays. Histopathological results confirmed the diagnosis of lipoma. Although most giant dorsal neck lipomas are benign, they may be a cause for neck pain, headaches and degenerative changes in the cervical spine, undermining the quality of life. Such symptoms should be assessed, and removal recommended.


Assuntos
Lipoma , Cervicalgia , Cefaleia , Humanos , Lipoma/complicações , Lipoma/diagnóstico por imagem , Lipoma/cirurgia , Masculino , Pessoa de Meia-Idade , Pescoço/patologia , Cervicalgia/etiologia , Cervicalgia/cirurgia , Qualidade de Vida
3.
Microsurgery ; 41(4): 335-340, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33675678

RESUMO

BACKGROUND: Reconstruction of perineal defect is challenging. The goal of reconstruction is to maintain normal function with good esthetic outcomes. Coverage of the perineal defect is often difficult with one loco-regional flap when the size of defect is very extensive. In this article, clinical applications of the propeller posteromedial thigh perforator (PMTP) flap for extensive perineal defects were described. PATIENTS AND METHODS: Eight patients underwent perineal reconstruction with propeller PMTP flaps from March 2013 to December 2018. The average age of the patients was 65 years (range: 52-80 years). The causes of the defects included infection and skin cancers. The perforator was a branch of deep femoral artery. The flap was harvested as a perforator-based flap and rotated 180° to the defect area (propeller flap design). RESULTS: The average flap size was 256.5 cm2 (range: 136-400 cm2 ) and average follow-up period was 22.4 months (range: 6-48 months). All flaps survived after surgery without major complications. The donor sites were all primarily closed and the patients were all satisfied during the follow-up period. CONCLUSION: The propeller PMTP flap is an adequate new option for reconstructing extensive perineal defects. The flap avoids the need for microanastomosis and replaces the defect with similar tissue.


Assuntos
Retalho Perfurante , Procedimentos de Cirurgia Plástica , Neoplasias Cutâneas , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Períneo/cirurgia , Neoplasias Cutâneas/cirurgia , Coxa da Perna/cirurgia
4.
Microb Ecol ; 79(4): 801-814, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31705158

RESUMO

Freshwater planktonic communities comprise a tremendous diversity of microorganisms. This study investigated the distribution patterns of microbial kingdoms (bacteria, fungi, protists, and microbial metazoans) within a lake ecosystem. Water samples were collected from 50 sites along the shoreline in a lake during an early eutrophication period, and MiSeq sequencing was performed with different marker genes. Metacommunity analyses revealed a bimodal occupancy-frequency distribution and a Clementsian gradient persisting throughout all microbial kingdoms, suggesting similar regional processes in all kingdoms. Variation partitioning revealed that environmental characteristics, macrophyte/macroinvertebrate composition, space coordinates, and distance-based Moran's eigenvector maps (dbMEM) together could explain up to 29% of the community variances in microbial kingdoms. Kingdom synchrony results showed strong couplings between kingdoms (R2 ≥ 0.31), except between Fungi and Metazoa (R2 = 0.09). Another variation partitioning revealed that microbial kingdoms could well explain their community variances up to 73%. Interestingly, the kingdom Protista was best synchronized with the other kingdoms. A correlation network showed that positive associations between kingdoms outnumbered the negative ones and that the kingdom Protista acted as a hub among kingdoms. Module analysis showed that network modules included multi-kingdom associations that were prevalent. Our findings suggest that protists coordinate community assembly and distribution of other kingdoms, and inter-kingdom interactions are a key determinant in shaping their community structures in a freshwater lake.


Assuntos
Lagos/microbiologia , Microbiota , Animais , Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Lagos/parasitologia , República da Coreia , Análise Espacial
5.
Int Wound J ; 13 Suppl 1: 7-12, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26847934

RESUMO

Treating patients with multiple pressure ulcers is a very challenging task for physicians. However, there are very few reports on treatment protocols for multiple pressure ulcers and treatment outcomes. The authors have consistently treated multiple pressure ulcers in a one-stage operation rather than a staged operation. We evaluated multiple pressure ulcers patients who underwent a one-stage operation from 2007 to 2014. A comparison was made between 20 patients who underwent a one-stage operation on 44 foci and 68 patients with a single focus. Though the results, we could conclude that one-stage operation of multiple pressure ulcers was found to have a shorter recovery period and shorter hospitalization without a significant increase in complications.


Assuntos
Úlcera por Pressão/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Úlcera por Pressão/patologia , Estudos Retrospectivos , Retalhos Cirúrgicos , Adulto Jovem
6.
Microsurgery ; 35(8): 627-33, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26461172

RESUMO

OBJECTIVE: Extensive defects of the perineal or inguinal area require well vascularized free flap coverage. This area has an abundance of perforating arteries and veins based on vessels from the femoral artery and internal iliac artery. We present our experience on the use of perforators as recipient vessels in reconstructing soft tissue defects of the perineal and inguinal area with free flaps. PATIENTS AND METHODS: From March 2012 to August 2014, 13 patients underwent free flap reconstruction for soft tissue defects of the inguinal or perineal area. Perforating arteries with diameters ranging from 0.7 to 1.2 mm were used as recipient arteries. Accompanying veins or neighboring superficial veins were secured as recipient veins. RESULTS: All flaps survived attached to a recipient perforator with a diameter ranging from 0.7 to 1.2 mm. These vessels were found in the inguinal or perineal areas, regions that are supplied by the superficial circumflex iliac vessels, superficial inferior epigastric vessels, superficial and deep external pudendal vessels, lateral and medial circumflex femoral vessels, and internal pudendal vessels. There were no cases of arterial insufficiency or venous congestion, flap necrosis, or infection. A single case of hematoma beneath the flap was treated by simple evacuation. There were no donor complications. CONCLUSION: Using perforators as the recipient during free flap reconstruction of the inguinal and perinea area allows the surgeon to choose from a wider choice of vessels, and yields acceptable flap survival.


Assuntos
Retalhos de Tecido Biológico/transplante , Virilha/irrigação sanguínea , Períneo/irrigação sanguínea , Procedimentos de Cirurgia Plástica/métodos , Lesões dos Tecidos Moles/cirurgia , Adulto , Idoso , Anastomose Cirúrgica , Artérias/cirurgia , Feminino , Retalhos de Tecido Biológico/irrigação sanguínea , Sobrevivência de Enxerto , Virilha/lesões , Virilha/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Períneo/lesões , Períneo/cirurgia , Resultado do Tratamento , Veias/cirurgia
7.
J Craniofac Surg ; 25(4): e343-4, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25006939

RESUMO

In this article, we will examine a case of cutaneous angiomyolipoma in the right nasal alar base area of a 36-year-old man. Generally, angiomyolipoma occurs in the kidney and, histologically, has features that are similar to cutaneous angiomyolipoma: smooth muscle cells, mature adipose cells, and a convoluted thick-walled blood vessel. Clinically, renal angiomyolipoma is related to tuberous sclerosis, but cutaneous angiomyolipomas occur very rarely, with a total of only 23 cases documented in the literature, with 39% (9/23) of those cases occurring in the ear or surrounding areas. In particular, the abundance of blood vessels inside a cutaneous angiomyolipoma produces good enhancement on computed tomographic image, making it easy for the tumor to be mistaken for a vascular tumor. In this particular case, we will report about a previously unheard case of cutaneous angiomyolipoma occurring in the nasal alar base that was mistaken for a vascular tumor.


Assuntos
Angiomiolipoma/diagnóstico por imagem , Neoplasias Nasais/diagnóstico por imagem , Neoplasias Cutâneas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Angiomiolipoma/patologia , Angiomiolipoma/cirurgia , Erros de Diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasais/patologia , Neoplasias Nasais/cirurgia , Pele/patologia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/cirurgia
8.
Animals (Basel) ; 13(13)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37443968

RESUMO

In this study, we hypothesized that the limited geographical distribution of Pseudopungtungia tenuicorpa in South Korea is closely related to the local abundance of their preferred spawning habitats. Eggs of P. tenuicorpa were most frequently observed in cracks smaller than 5 cm, followed by the nests of other fish, such as Coreoperca herzi. Although eggs of P. tenuicorpa were also found in cracks larger than 6 cm, most of them were consumed or damaged by other fish. However, the number of P. tenuicorpa eggs spawned in cracks smaller than 5 cm remained similar to the number of eggs at the time of initial spawning, even after 9 days. The strong preference of P. tenuicorpa for cracks smaller than 5 cm was found to influence the geographical distribution of P. tenuicorpa in South Korea. In the upper reaches of the Han River, the ratio of cracks smaller than 5 cm is higher than that in the Geum River and in the Nakdong River, which contributes to the stable population growth of P. tenuicorpa there. In the future, management strategies to maintain/restore cracks smaller than 5 cm should be reviewed for the preservation of this endemic fish in South Korea.

9.
Mitochondrial DNA B Resour ; 8(3): 333-335, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36876145

RESUMO

Ischnura asiatica (Brauer, 1865) is a freshwater damselfly belonging to the family Coenagrionidae that is distributed across most of Korea, primarily in areas with low water flow, such as ponds and wetlands. The complete mitochondrial genome of I. asiatica was sequenced by next-generation sequencing. The circular mitochondrial genome was found to be 15,769 bp long, with of 13 protein-coding, two ribosomal RNA, and 22 transfer RNA genes (GenBank accession no. OM310774). Maximum likelihood, phylogenetic analysis showed that this species clustered with other species belonging to the family Coenagrionidae. This study contributes to the phylogeny of damselflies and other members of the family Coenagrionidae.

10.
Jt Dis Relat Surg ; 34(2): 469-473, 2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37462654

RESUMO

Lipoma is a very common benign tumor that occurs in areas of adipose tissue and is commonly found on the whole body, although its occurrence in the hand and finger is rare. Giant lipoma, defined as over 5 cm long in diameter, is a rare benign tumor of abundant soft tissue in the finger. A 24-year-old male patient presented with a giant lipoma on the volar aspect of the index finger of his right hand. Magnetic resonance imaging (MRI) showed an encased multilobulated mass that measured 7.1x1.2x2.3 cm, and histopathological examination revealed lipoma without malignant transformation. Surgical resection of the tumor with a longitudinal and zig-zag incision of the palm was performed exposing the mass surrounding the palmar digital branch of the median nerve. The mass was completely removed, and neurorrhaphy was performed via the microscope to repair the damaged neurovascular bundle. At four months of postoperative follow-up, the patient was completely recovered with no finger paresthesia or limitation of range of motion. As a professional swimmer, the patient has experienced no subsequent difficulty in swimming due to his finger.


Assuntos
Lipoma , Neoplasias de Tecidos Moles , Masculino , Humanos , Adulto Jovem , Adulto , Neoplasias de Tecidos Moles/diagnóstico por imagem , Neoplasias de Tecidos Moles/cirurgia , Dedos/diagnóstico por imagem , Dedos/cirurgia , Mãos/cirurgia , Mãos/patologia , Lipoma/diagnóstico por imagem , Lipoma/cirurgia , Tecido Adiposo
11.
Gland Surg ; 12(8): 1131-1136, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37701296

RESUMO

Background: Breast augmentation is one of the most commonly performed aesthetic procedures in the world. Aquafilling filler, since its introduction in 2005 has been used for breast or buttock augmentation in several countries. Aquafilling filler is composed of 2% polyacrylamide with 98% sodium chloride 0.9% solution, and is known to have a similar composition with polyacrylamide hydrogel (PAAG) filler, which is also related to a variety of complications. Although many studies have warned against the complications of aquafilling filler, it is still being used for aesthetic purposes. Case Description: In this case report, we share our experience of a 36-year-old female patient complaining of smaller left breast and bulging mass in her left upper abdomen. She had a history of transumbilical breast augmentation (TUBA) 11 years prior, which she had had removed via the transumbilical incision 6 years ago. To compensate for the removal of implants, the patient had received large volumes of aquafilling filler injection 2 years after implant removal. Surprisingly, we found out that the filler in the left breast had displaced to the abdominal area. Conclusions: Accidently displacement may occur, especially in patients who have had previous procedures breaching the inframammary fold including TUBA. Therefore, it is required to observe carefully for those patients who have received breast augmentation or the breast filler injections.

12.
Jt Dis Relat Surg ; 34(3): 737-740, 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37750281

RESUMO

Dupuytren's disease is a fibroproliferative disease that affects the palmar hand, causing progressive, permanent, and symptomatic flexion contracture of the digits. It is a disorder of polygenetic and multifactorial origin, usually affecting middle-aged males. Dupuytren's disease developing as a result of hand trauma in younger ages is rarely reported. In this case, we present a 14-year-old male patient with Dupuytren's disease following acute traumatic injury. We performed the fasciectomy and Z-plasty with full thickness skin graft. He recovered completely additional injection of triamcinolone for one year.


Assuntos
Contratura de Dupuytren , Traumatismos da Mão , Masculino , Pessoa de Meia-Idade , Adolescente , Humanos , Contratura de Dupuytren/diagnóstico , Contratura de Dupuytren/cirurgia , Mãos , Traumatismos da Mão/complicações , Traumatismos da Mão/cirurgia , Extremidade Superior , Transplante de Pele
13.
Int J Low Extrem Wounds ; 22(4): 767-773, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34791920

RESUMO

Malignant transformation of chronic burn scars are usually toward cutaneous lineages, including squamous cell carcinoma, basal cell carcinoma, and malignant melanoma. Sarcomas are less common. Undifferentiated pleomorphic sarcoma(UPS) is a subtype of soft tissue sarcoma with storiform-pleomorphic cells of uncertain origin, and has sparingly been reported to arise from burn scars. The majority are localized lesions probably due to the spatial distance of mesenchymal cells from the epithelium. The authors describe a rare case of UPS of the chronic burn scar of his knee with ipsilateral femoral and external iliac lymph node metastasis.


Assuntos
Queimaduras , Histiocitoma Fibroso Maligno , Sarcoma , Humanos , Cicatriz , Metástase Linfática , Histiocitoma Fibroso Maligno/patologia , Sarcoma/patologia
14.
J Plast Surg Hand Surg ; 56(4): 242-248, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34658304

RESUMO

Widespread use of smartphones and wireless internet have made YouTube an easily accessible educational modality. Many residents use YouTube to acquire knowledge regarding microsurgical techniques; however, its quality and effect has not been verified. We included 22 residents working in the Department of Plastic and Reconstructive Surgery at our institute. Using block randomization, seven were allocated to a textbook group (TG), eight to a free-searching group (FSG), and seven to a designated-video group (DVG). After reviewing textbooks, YouTube videos, or designated videos, respectively, each group performed microsurgical anastomosis using artificial vessels. The total procedure time, Objective Structured Assessment of Technical Skills (OSATS), operative errors, and degree of leakage were assessed by blinded evaluators. Self-confidence rates were also compared. The YouTube groups (FSG and DVG) performed better than the TG. Although procedure time was significantly longer in the DVG (p = .006), the performance of DVG was better than that of TG in all assessments (OSATS: p = .012; operative errors: p = .002; leakage: p = .010). FSG showed more operative errors (p = .004) and leakage (p = .007) compared to DVG, but had higher OSATS (p = .008) and fewer operative errors (p = .002) than TG. The post-intervention confidence rates were significantly higher in FSG and DVG compared to TG (p = .002 and p = .001, respectively). Although there are concerns regarding the reliability of YouTube videos, microsurgery videos on YouTube had positive effects on microsurgery practice. Therefore, YouTube may help to improve the microsurgical skills of residents. If a quality control system is introduced for YouTube videos, their educational effects may be enhanced.


Assuntos
Mídias Sociais , Avaliação Educacional , Microcirurgia , Reprodutibilidade dos Testes , Gravação em Vídeo/métodos
15.
Biology (Basel) ; 11(10)2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36290312

RESUMO

Morphological or behavioral defense mechanisms are important evolutionary strategies for the survival of prey. Studies have focused on predation and competition, but infection has been overlooked, despite being a determining factor of distribution and species diversity of prey. We hypothesized that the winter migration of Daphnia pulicaria is a community defense strategy to avoid fungal infection. To test this hypothesis, environmental variables and the Cladocera community, including D. pulicaria, were monitored in three study sections of the Anri Reservoir in the Republic of Korea during September 2010-August 2015. During three winter seasons, the density of infected D. pulicaria increased in all study sections, and they migrated from the central to the littoral area. Most of the infected individuals had dormant eggs in sexually reproducing mothers. However, when the proportion of non-infected individuals was higher than that of infected individuals, winter migration was not observed. Additional microcosm experiments showed that dormant eggs of D. pulicaria obtained from ice crystals in the littoral area had lower hatching and infection rates than those obtained from mothers moving from other zones. Therefore, the migration of D. pulicaria during winter is an active response to avoid intergenerational fungal infection.

16.
Animals (Basel) ; 12(4)2022 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-35203169

RESUMO

Hydrological characteristics of freshwater ecosystems are powerful determinants of the distribution of biological communities and changes in environmental factors. This study identified relationships between the wetland environment, rotifer community, and hydrological factors for 48 wetlands, to determine their impact on wetland conservation and management. Different hydrological factors produced different wetland environments, which influenced the rotifer community composition. The wetlands with "poor" "in/outflow function" and "shore stability" levels showed high conductivity, turbidity, depth, and concentrations of total nitrogen, total phosphorus, and chlorophyll a. In contrast, the dissolved oxygen levels and velocity were the highest in wetlands with "good" in/outflow function and shore stability variables. The nutritional status of each wetland affected the composition of the rotifer community. Some genera (Keratella, Brachionus, Anuraeopsis, Trichocerca, and Philodina) were found in wetlands with high concentrations of total nitrogen, total phosphorus, and chlorophyll a, and high turbidity and depth. In contrast, Ascomorpha and Ploesoma were found in wetlands with high dissolved oxygen levels and flow velocity. High densities of Lepadella, Lecane, and Testudinella were found in wetlands completely covered by macrophytes. The rotifer community distribution can be used to understand the trophic, current functional, and environmental status of wetlands.

17.
Arch Plast Surg ; 49(1): 76-79, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35086314

RESUMO

Kienböck disease, a rare disease that can cause chronic pain and motor dysfunction, occurs due to avascular necrosis of the lunate bone, which leads to dislocation of the carpal bone. Among various other etiologies, Kienböck disease can cause closed tendon rupture of the finger. In this report, we introduce a case of total rupture of the second extensor digitorum communis and the extensor indicis proprius tendons caused by undiagnosed Kienböck disease in an elderly female patient.

18.
J Clin Med ; 11(24)2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36556005

RESUMO

Background: The latissimus dorsi myocutaneous (LDMC) flap is a preferred flap in breast reconstruction for its wide surface area and volume. Since the flap is situated in the midback area, a lateral decubitus approach is a conventional method. However, proper visualization and access to the thoracodorsal vascular pedicle or muscle insertion is difficult from the lateral approach, causing inefficiency and surgeon fatigue. We propose the 'anterior-first' approach in LDMC flap reconstruction, where the landmark structures are first approached from the supine-anterior position through the mastectomy incision. Methods: From January 2014 to December 2020, 48 patients who received immediate breast reconstruction with LDMC flap were included in the study. Patients received reconstruction with the conventional approach (n = 20), or anterior-first approach (n = 28). Demographic factors and the operative outcomes were retrospectively analyzed and compared between the two groups. Results: Compared to the conventional approach group, the anterior-first approach group showed improved efficiency in the duration of total reconstruction (228 versus 330 min, p < 0.001), and flap elevation (139 versus 200 min, p < 0.001). No difference in complication rate and time to drain removal was observed (p = 0.14 and >0.9, respectively). Conclusion: The anterior-first approach for breast reconstruction with LDMC flap provides surgeons with an enhanced surgical exposure and superior ergonomics, leading to a safer and more efficient flap elevation.

19.
Biology (Basel) ; 10(5)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062893

RESUMO

Frequent predation induces various defense strategies in prey, including morphological changes or migration patterns in zooplankton. We hypothesized that the winter dominance of Cyclops vicinus in the Upo Wetlands, South Korea, is an evolved temporal defense mechanism to avoid fish predation. Long-term data (2014-2019) showed that fish consumed the most cyclopoid copepods from spring to autumn. Lepomis macrochirus preferentially consumed C. vicinus; thus, C. vicinus density was lower from spring to autumn. However, C. vicinus was abundant in winter when fish consumed fewer copepods. Nauplii density began to increase in late autumn (October-November), and their population growth was fueled through consumption of Cyclotella sp. and Rhodomonas sp. Culture experiments showed that Cyclotella sp. contributed more to the growth stage (copepodite or subadult) after nauplii than Rhodomonas sp. C. vicinus density was lower in the winters of 2013 and 2016 when the densities of these phytoplankton prey species were lower. In summary, although winter conditions were suitable for copepod survival and population growth, C. vicinus relied heavily on the diversity and species composition of its food sources. The winter dominance of C. vicinus could increase regional biodiversity and contribute significantly to the stability of the freshwater food web.

20.
Microorganisms ; 9(9)2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34576856

RESUMO

The acquisition of Antibiotic-Resistance Genes (ARGs) by natural bacteria caused by antibiotic abuse is causing serious problems for human and animal welfare. Here, we evaluated the influence of three cladoceran species on Antibiotic-Resistant Bacteria (ARB) and tetracycline-resistance gene (tet(A)) copies, and discussed the effect of these biological interactions on the distribution and diffusion of ARGs in freshwater ecosystems. Bacterial community and tet(A) abundances in water samples collected from wetlands were strongly influenced by cladoceran presence. The presence of Daphnia obtusa dramatically decreased ARB and tet(A) abundance compared to that with other cladoceran species (Chydorus sphaericus and Simocephalus vetulus). Interestingly, we found a high abundance of Flavobacteriales in the microbiomes of cladoceran species. Considering that Flavobacteriales species are potential carriers of the tet(A) gene, their adsorption and assimilation with cladocerans could significantly impact the reduction of tet(A) in water. Field surveys also showed that tet(A) abundance could be low if the dominance of D. obtusa in each wetland was high. This study highlighted the need for ecological interactions and a broad range of niches in the food web when discussing the fate of ARGs in freshwater ecosystems.

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