Caustics and wavefronts produced by multiple refraction-reflections through plane-parallel plates.

We study the formation of caustics and wavefronts produced by multiple refraction-reflections through a plane-parallel transparent plate, assuming a point source placed at an arbitrary position along the optical axis. The caustic surfaces are obtained by using the envelope's method. Subsequently, the wavefronts are directly related to the involutes, which are associated with the envelopes for all the rays. Hence by using the Malus-Dupin theorem, we obtain their respective wavefronts produced by multiple refraction-reflections through a plane-parallel transparent plate. On the other hand, we implement Huygens' principle to obtain the wavefronts leaving the plate after undergoing multiple reflections inside the plate, which we have called zero-distance phase wavefronts. Finally, we establish the correspondence between the wavefronts obtained by Huygens' principle and the involutes associated with caustic surfaces; they are brought in coincidence assuming parallel curves from each other.

Three new species of the sea fan genus Muricea (Cnidaria, Octocorallia, Plexauridae) from the northwest region of Mexico.

Twenty-one nominal species of Muricea have been reported in the Eastern Pacific with nine of them reported in the Mexican Pacific. We describe three new species of Muricea: Muriceaambaraesp. nov. and Muriceacacaosp. nov., from rocky reefs on the central and the northern Gulf of California and the Pacific coast of Baja California Sur, and Muriceamolinaisp. nov., from the Pacific coast of Baja California Sur. Muriceaambaraesp. nov. and M.cacaosp. nov. are taxonomically allied to the nominal species Muriceafruticosa Verrill, 1869 due to the morphological similarity of colony growth patterns and the phylogenetic closeness based on the mitochondrial MutS gene (mtMutS); but differ mainly in the calyx form and composition of sclerites. The main morphological differences between the new Muricea species are in their sclerite forms and color; M.ambaraesp. nov. has orange-colored colonies, thin leaf spindles and tuberculated blunt spindles, while M.cacaosp. nov. has dark brown colored colonies, strong spinous spindles and an absence of tuberculated blunt spindles. Muriceamolinaisp. nov. is phylogenetically close and morphologically similar to Muriceasquarrosa Verrill, 1869 in the growth form of the colony and tubular calyces; but has dark brown colored colonies and has calyces from the base to the branch tips. With these three new species, the total number of Muricea species reported in the Mexican northwest region increases to twelve and a total of 24 nominal species in the Eastern Pacific.

Case report: Primary adenocarcinoma NOS of the thymus and cytological features.

Aspirates of mediastinal neoplasms pose a unique diagnostic challenge due to the overlapping histologic characteristics of mediastinal lesions and the morphologic similarities between mediastinal neoplasms and those originating at other sites. Presented here is the first reported description of the cytomorphologic features of adenocarcinoma NOS of the thymus in aspirate and pleural effusion specimens. The morphologic similarities between thymic and metastatic adenocarcinomas and variable immunohistochemical staining patterns of thymic epithelial neoplasms underscore the importance of pathology-radiology correlation and the careful consideration of the clinical context in the interpretation of cytology specimens.

Active Surveillance for Atypical Ductal Hyperplasia and Ductal Carcinoma In Situ.

Atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) are relatively common breast lesions on the same spectrum of disease. Atypical ductal hyperblasia is a nonmalignant, high-risk lesion, and DCIS is a noninvasive malignancy. While a benefit of screening mammography is early cancer detection, it also leads to increased biopsy diagnosis of noninvasive lesions. Previously, treatment guidelines for both entities included surgical excision because of the risk of upgrade to invasive cancer after surgery and risk of progression to invasive cancer for DCIS. However, this universal management approach is not optimal for all patients because most lesions are not upgraded after surgery. Furthermore, some DCIS lesions do not progress to clinically significant invasive cancer. Overtreatment of high-risk lesions and DCIS is considered a burden on patients and clinicians and is a strain on the health care system. Extensive research has identified many potential histologic, clinical, and imaging factors that may predict ADH and DCIS upgrade and thereby help clinicians select which patients should undergo surgery and which may be appropriate for active surveillance (AS) with imaging. Additionally, multiple clinical trials are currently underway to evaluate whether AS for DCIS is feasible for a select group of patients. Recent advances in MRI, artificial intelligence, and molecular markers may also have an important role to play in stratifying patients and delineating best management guidelines. This review article discusses the available evidence regarding the feasibility and limitations of AS for ADH and DCIS, as well as recent advances in patient risk stratification.

The Milan System for Reporting Salivary Gland Cytopathology.

OBJECTIVES: Our study assesses whether the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) offers any benefit over the original cytology classification, and measures interobserver agreement. METHODS: Four cytopathologists retrospectively blindly classified preoperative cytology by MSRSGC from 101 resected salivary tumors. Consensus MSRSGC diagnoses were correlated with surgical pathology diagnoses and compared with the original cytology classification. Diagnostic parameters were calculated for both systems. Interobserver variability was assessed. RESULTS: The original cytology classification vs MSRSGC had sensitivity, specificity, positive predictive value, and negative predictive value of 75.0% vs 78.3%, 97.1% vs 98.0%, 91.2% vs 94.7%, and 90.1% vs 90.0%, respectively. The original cytology classification risk of neoplasm (RON) was 91.7% for "negative for malignancy" and 100.0% for other categories. The MSRSGC RON was 71.4% in category II (nonneoplastic) and 100.0% in all other categories. The original cytology classification risk of malignancy (ROM) ranged from 0.0% for "atypical" to 100.0% for "positive for malignancy." The MSRSGC ROM ranged from 0.0% in categories I (nondiagnostic) and III (nonneoplastic) to 100.0% in category VI (malignant). Weighted agreement using the MSRSGC was 92% (Gwet AC1, 0.84); unweighted agreement was 69% (Gwet AC1, 0.64). MSRSGC category IVA (benign neoplasm) was most likely to show interobserver agreement, with complete agreement in 67% of cases. CONCLUSIONS: The MSRSGC performs similarly to the original cytology classification and shows relatively high interobserver agreement.

De Novo Transcriptome of Mammillaria bombycina (Cactaceae) under In Vitro Conditions and Identification of Glyoxalase Genes.

Mammillaria bombycina is a cactus distributed in the central region of Mexico. Cactaceae have the particularity of surviving drought and high temperatures, which is why in vitro propagation studies have been carried out successfully to preserve this species and use it as a study model in cacti. In this contribution, a de novo transcriptome of M. bombycina was produced under in vitro conditions for the identification and expression of genes related to abiotic stress. Samples were sequenced using an Illumina platform, averaging 24 million clean readings. From assembly and annotation, 84,975 transcripts were generated, 55% of which were unigenes. Among these, the presence of 13 isoforms of genes belonging to glyoxalase I, II and III were identified. An analysis of the qRT-PCR expression of these genes was performed under in vitro and ex vitro conditions and dehydration at 6 and 24 h. The highest expression was observed under greenhouse conditions and dehydration at 24 h, according to the control. The de novo assembly of the M. bombycina transcriptome remains a study model for future work in cacti.

Myopericytoma of the Parotid and Molecular Profiling: Report of a Rare Case and Review of the Literature.

Myopericytomas are uncommon tumors defined by their round to spindle shaped cells often arranged in a concentric pattern of perivascular growth. They are typically well-circumscribed, nodular, slow-growing lesions that occur in the soft tissue of the extremities. Here, we present a 30-year-old female with a 2.4 cm myopericytoma occurring in the deep lobe of the parotid gland. The diagnosis was made with detailed histopathologic and immunohistochemical findings and positive identification of the specific mutation for PDGFRß p.Asp666Lys by next generation sequencing (NGS). This is the first case report of a parotid myopericytoma with a genetic testing that shows a particular mutation that has been linked to myopericytomatosis.

Synergy Effects in Heavy Metal Ion Chelation with Aryl- and Aroyl-Substituted Thiourea Derivatives.

Detection and removal of metal ion contaminants have attracted great interest due to the health risks that they represent for humans and wildlife. Among the proposed compounds developed for these purposes, thiourea derivatives have been shown as quite efficient chelating agents of metal cations and have been proposed for heavy metal ion removal and for components of high-selectivity sensors. Understanding the nature of metal-ionophore activity for these compounds is thus of high relevance. We present a theoretical study on the interaction between substituted thioureas and metal cations, namely, Cd2+, Hg2+, and Pb2+. Two substituent groups have been chosen: 2-furoyl and m-trifluoromethylphenyl. Combining density functional theory simulations with wave function analysis techniques, we study the nature of the metal-thiourea interaction and characterize the bonding properties. Here, it is shown how the N,N'-disubstituted derivative has a strong affinity for Hg2+, through cation-hydrogen interactions, due to its greater oxidizing capacity.

p16 immunostaining in fine-needle aspirations of the head and neck: determining the optimal positivity threshold in HPV-related squamous cell cancer.

INTRODUCTION: There is no consensus for interpretation of p16 immunohistochemistry (IHC) in cytology preparations. Our study aims to assess p16 IHC staining in formalin-fixed cytology cell blocks (CBs) from head and neck squamous cell carcinoma (HNSCC) fine-needle aspiration (FNA) specimens in comparison with surgical pathology p16 staining and to determine the reproducibility of p16 IHC scoring in CBs. METHODS: A total of 40 FNAs from 2014 to 2019 of HNSCC with p16 IHC were obtained. CB p16 staining was scored independently by 5 cytopathologists as interval percentages of tumor cell positivity. Receiver operating characteristic (ROC) curves were examined to determine optimal cutoffs for each pathologist based on sensitivity and specificity values. Gwet's coefficient (AC1) was calculated to assess inter-rater reliability. RESULTS: Greater than 10% was the lowest threshold to reach 100% specificity with high sensitivity (55%-84%) in all 5 raters. Rater performances were similar, with areas under the curve (AUCs) ranging from 0.89 to 0.95. Using the >10% threshold, Gwet's AC1 = 0.72 (95% CI: 0.56-0.89). Diagnostic performance improved further when low-cellularity cases were excluded, with AUC ranging from 0.94 to 0.99 and Gwet's AC1 = 0.79 (95% CI: 0.61-0.98). CONCLUSION: p16 IHC performed on cytology CBs can serve as a surrogate marker for the detection of HPV with high sensitivity and specificity levels. Using a threshold lower than that recommended for surgical pathology for the interpretation of p16 positivity may be appropriate for FNA cytology CB preparations. All cytopathologists in our study displayed reproducible high sensitivity and specificity values at the >10% threshold.

Genetic profile of primary mucinous cystadenocarcinoma of the breast-A case report.

Primary mucinous cystadenocarcinoma of the breast is a rare neoplasm with few reports in the literature. Here, we report for the first time a comprehensive genetic profile of a primary mucinous cystadenocarcinoma of the breast, using next-generation sequencing 580 cancer-associated gene panel. Mutations in TP53, RB1, and BAP1 were identified. The findings suggest that this tumor is driven mostly by abnormalities in tumor suppressor genes, primarily involved in cell cycle control and chromatin remodeling. Molecular characterization of additional primary mucinous cystadenocarcinomas of the breast is warranted and might provide information related to its biology and behavior.

One-minute and green synthesis of magnetic iron oxide nanoparticles assisted by design of experiments and high energy ultrasound: Application to biosensing and immunoprecipitation.

The present study is focused on the ultrafast and green synthesis, via the co-precipitation method, of magnetic nanoparticles (MNPs) based on iron oxides using design of experiments (DOE) and high energy sonochemical approach, considering two main factors: amplitude (energy) of the ultrasound probe and sonication time. The combination of these techniques allowed the development of a novel one-minute green synthesis, which drastically reduced the amount of consumed energy, solvents, reagents, time and produced residues. This green sonochemical synthesis permitted to obtain mean particle sizes of 11 ± 2 nm under the optimized conditions of amplitude = 40% (2826 J) and time = 1 min. Their composition, structure, size, morphology and magnetic properties were assessed through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning and transmission electron microscopy (SEM & TEM), and vibrating sample magnetometry (VSM). The characterization results indicate the proper formation of MNPs, and the correct functionalization of MNPs with different coating agents. The functionalized MNPs were used as: i) biosensor, which could detect mercury in water in the range of 0.030-0.060 ppm, and ii) support onto which polyclonal antibodies were anchored and successfully bound to an osteosarcoma cell line expressing the target protein (TRIB2-GFP), as part of an immunoprecipitation assay.

Three new species of the sea fan genus Leptogorgia (Octocorallia, Gorgoniidae) from the Gulf of California, Mexico.

Three new sea fan species of Leptogorgia were discovered during multiple scuba diving expeditions along the Gulf of California coast and islands. Leptogorgia iridis sp. nov. is distributed in the southern region of the gulf (Mexican Province), inhabiting tropical rocky reefs of the Islas Marías Archipelago (Nayarit) and Bahía Banderas (Jalisco). This species has small colonies (< 7 cm height) with at least five clearly distinct chromotypes. Leptogorgia martirensis sp. nov. was found exclusively on the rocky reefs of San Pedro Mártir and San Esteban Islands located in the northern region of the Gulf of California (northern region of Cortez Province). Leptogorgia enrici sp. nov. is distributed from the south to the northern region of the Gulf of California (Cortez Province), inhabiting substrates of rocky reefs, sandy and pebbly sea floors. Comprehensive ecological diving expeditions to identify and classify octocorals in the Mexican Pacific (1995-2019) indicate that L. iridis sp. nov. and L. martirensis sp. nov. are likely to be micro-endemics and L. enrici sp. nov. is endemic to the Gulf of California, which defines their currently known biogeographic distribution ranges.

Sweating and core temperature in athletes training in continuous and intermittent sports in tropical climate / Sudoración y temperatura interna en atletas durante entrenamiento para deportes continuos e intermitentes en clima tropical

Higher sweat rate values have been reported during intermittent compared to continuous type exercise in hot conditions in the laboratory. Studies in the training field are scarce. Objective: Document sweat rate, rehydration and core temperature (Tc) during training in long duration-continuous (CON) and intermittent (INT ) type sports, and determine the presence of a mutation in the CFTR gene in athletes with high sodium concentration ([Na+]) in sweat.Methods: Athletes (CON =50 and INT=123) were tested during training in tropical climate. Sweat rate, sweat [Na+], Tc, de-hydration level, and presence of ∆ F508 gene mutation in the CFTR gene in athletes with high sweat [Na+] were evaluated. Results: Sweat rate was higher in CON (1.5 ± 0.4 L/h) compared to INT (1.2 ± 0.5 L/h) and CON athletes finished training with higher dehydration (2.1 ± 0.8 vs 1.2 ± 0.7%) P < 0.05. Sweat [Na+] was higher in INT (62.0 ± 21.1 mmol/L) compared to CON (53.9 ± 18.1 mmol/L), P < 0.05. A tennis player with high [Na+] was heterozygous for the ΔF508 mutation. Average and highest Tc was similar for CON (38.4 ± 0.3 and 38.8 ± 0.4 oC) and INT (38.3 ± 0.3 and 38.7 ± 0.4 oC), P > 0.05. Conclusion: During training in a tropical climate, sweat loss and dehydration level are lower, and fluid intake is higher in intermittent compared to continuous type sports. Core temperature may rise to a similar level in intermittent type sports due to the repeated high intensity bouts and/or the effects of clothing worn while training in hot venues. Healthy athletes with high [Na+] in sweat who are heterozygous carriers of CFTR mutations may be at increased risk for hyponatremic dehydration and whole-body muscle cramps

Se reportan tasas de sudoración más altas durante ejercicio intermitente comparado con continuo en condiciones de calor en el laboratorio. Estudios en el campo de entrenamiento son escasos. Objetivo: Documentar la tasa de sudoración, rehidratación y temperatura central (Tc) durante entrenamiento para deportes de tipo continuo (CON) e intermitente (INT ), y determinar presencia de mutación genética en el gen CFTR en atletas con alta concentración de sodio ([Na+]) en sudor.Metodología: Se evaluó la tasa de sudoración, la [Na+] en sudor, la Tc, y el nivel de deshidratación en atletas (CON = 50; INT =123) durante entrenamiento en clima tropical, y la presencia de la mutación genética ∆F508 en el gen CFTR en aquellos con alta [Na+] en sudor.Resultados: La tasa de sudoración fue mayor en CON (1,5 ± 0,4 L/h) comparado con INT (1,2 ± 0,5 L/h) y los atletas en CON terminaron el entrenamiento con mayor deshidratación (2,1 ± 0,8 vs 1,2 ± 0,7%) P < 0,05. La [Na+] en sudor fue más alta en INT (62,0 ± 21,1 mmol/L) comparado con CON (53,9 ± 18,1 mmol/L), P < 0,05. Un tenista con alta [Na+] era heterocigoto para la mutación ΔF508. La Tc promedio y más alta fueron similares para CON (38,4 ± 0,3 y 38,8 ± 0,4 oC) e INT (38,3 ± 0,3 y 38,7 ± 0,4 oC), P > 0,05. Conclusión: Durante el entrenamiento en clima tropical, la pérdida de sudor y el nivel de deshidratación son más bajos, y la ingesta de líquido es más alta en deportes intermitentes que en deportes continuos. La temperatura interna puede aumentar a nivel similar en deportes intermitentes debido a periodos repetidos de alta intensidad y/o la vestimenta usada durante el entrenamiento. Atletas saludables con alta [Na+] en sudor que son heterocigóticos para mutaciones de CFTR pueden estar en mayor riesgo de deshidratación hiponatrémica y calambres musculares

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features: An interobserver study of key cytomorphological features from a large academic medical centre.

OBJECTIVE: Because of the indolent nature of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) and potential requisite for a more conservative treatment, it is crucial to identify features of this entity preoperatively. Our group recently published findings that there are several cytomorphological features that may be used as clues to distinguish NIFTP, papillary thyroid carcinoma (PTC) and follicular adenoma (FA) on fine needle aspiration. Therefore, we aimed to determine the interobserver reproducibility of these findings. METHODS: Presurgical fine-needle aspiration slides from NIFTP (n = 30), classic PTC (n = 30) and FA (n = 30) collected from 1/2013-8/2016 were reviewed by seven cytopathologists blindly. Presence of selected cytomorphological features was recorded and compared to determine percent agreement and inter-rater reliability among study cytopathologists using Gwet's AC1 statistics. RESULTS: For all the cytomorphological features, the overall percent agreement amongst the pathologists ranged between 65.1% and 86.8% (Gwet's AC1 0.30-0.80). There was substantial or almost perfect agreement (Gwet's AC1 > 0.60) in seven cytomorphological features in the classic PTC group, in six features in the NIFTP group and in five features in the FA group. There were no features with poor agreement (Gwet's AC1 < 0.0). CONCLUSIONS: The current study supports the reproducibility of our previous findings. The high level of agreement amongst pathologists for these groups, and particularly the NIFTP group, supports the notion that when viewed in combination as a cytological profile, these cytomorphological features may assist the cytopathologist in raising the possibility of NIFTP preoperatively. This can potentially aid clinicians in deciding whether more conservative treatment may be appropriate.

An Analysis of Nipple Enhancement at Breast MRI with Radiologic-Pathologic Correlation.

Breast MRI is the most sensitive imaging modality for assessment of the nipple-areola complex (NAC), which is important both in cancer staging and in high-risk screening. However, the normal appearance of the nipple at MRI is not well defined because of a paucity of scientific literature on this topic. Hence, there is a lack of descriptive terminology and diagnostic criteria, which may account for the wide variability in interpretation among radiologists when assessing the NAC on MR images. In light of the current shift toward possible expanded use of abbreviated (ie, fast) breast MRI for screening in women at average risk for cancer in particular, and because an increasing number of women now undergo nipple-sparing mastectomy for therapeutic and/or prophylactic indications, careful assessment of the NAC at MRI is essential. In this article, the normal pattern of nipple enhancement at MRI is defined on the basis of findings observed in healthy individuals, normal nipple enhancement at MRI is correlated with the structural anatomy of the nipple at histopathologic analysis, and artifacts and pitfalls related to MRI of the NAC are reviewed. Understanding the normal range of nipple morphology and enhancement at MRI is important, as it enables radiologists to better differentiate between normal and abnormal nipple findings with increased diagnostic confidence. ©RSNA, 2018 See discussion on this article by Cohen and Holbrook .

Two new endemic species of Gorgoniidae (Cnidaria, Anthozoa, Octocorallia) from Revillagigedo Archipelago, Mexico.

Two new species of the genera Eugorgia and Leptogorgia were discovered while underwater collecting at the Revillagigedo Archipelago, Mexico. Sea fan species diversity and density population in these four volcanic islands is low (<12 spp.), and the possibility of endemism is high given their isolation from the mainland (403 km southwest of Cabo San Lucas, Baja California peninsula). Morphological features suggest Eugorgia wilkiei sp. nov. has a close relationship to species of the daniana group, particularly with Eugorgia multifida Verrill, 1870. However, E. wilkiei sp. nov. has densely branched irregular-pinnate colonies that grow in several simple planes or multiplanar flabelliform, and shows two distinct chromotypes (yellow or red). Leptogorgia waltonae sp. nov. is added here to the ena group because its similar in size and sclerites to Leptogorgia ena Breedy et al. 2012. However, the wart-like terminal twigs representing an enlargement of the axis (but not the coenenchyme which has the same thickness throughout the colony), 90°-angled lateral branching, and the red, purple, orange, or yellow coloration range of the colonies are the main taxonomic characters to distinguish L. waltonae sp. nov. from L. ena. Scuba diving observations in about 200 sampling locations done since 1995 to 2016 along the mexican Pacific coast, including the Gulf of California, indicate both new octocoral species are distributed only at Revillagigedo islands. Revillagigedo Archipelago is surrounded by oligotrophic oceanic waters, strong seawater currents, and relatively frequent hurricane perturbations that favor small or robust, and hard and resistant sea fan colonies, low-species diversity, and low-population density. These factors may enhance speciation processes supporting the comparatively high endemism of the islands benthic fauna as well.

Interaction between FTO rs9939609 and the Native American-origin ABCA1 rs9282541 affects BMI in the admixed Mexican population.

BACKGROUND: The aim of this study was to explore whether interactions between FTO rs9939609 and ABCA1 rs9282541 affect BMI and waist circumference (WC), and could explain previously reported population differences in FTO-obesity and FTO-BMI associations in the Mexican and European populations. METHODS: A total of 3938 adults and 636 school-aged children from Central Mexico were genotyped for both polymorphisms. Subcutaneous and visceral adipose tissue biopsies from 22 class III obesity patients were analyzed for FTO and ABCA1 mRNA expression. Generalized linear models were used to test for associations and gene-gene interactions affecting BMI, WC and FTO expression. RESULTS: FTO and ABCA1 risk alleles were not individually associated with higher BMI or WC. However, in the absence of the ABCA1 risk allele, the FTO risk variant was significantly associated with higher BMI (P = 0.043) and marginally associated with higher WC (P = 0.067), as reported in Europeans. The gene-gene interaction affecting BMI and WC was statistically significant only in adults. FTO mRNA expression in subcutaneous abdominal adipose tissue according to ABCA1 genotype was consistent with these findings. CONCLUSIONS: This is the first report showing evidence of FTO and ABCA1 gene variant interactions affecting BMI, which may explain previously reported population differences. Further studies are needed to confirm this interaction.

Metastatic carcinoid tumor to the breast: report of two cases and review of the literature.

The breast is an unusual site for carcinoid metastasis. Due to increasing survival rates for carcinoid tumors, however, awareness of their rare complications is important. Carcinoid metastasis to the breast typically presents as a palpable breast mass or a mass on screening mammogram. Because imaging findings are nonspecific, the diagnosis is established through histological findings of neuroendocrine features corresponding with the known primary carcinoid pathology. Correctly distinguishing metastatic carcinoid from primary breast carcinoma is crucial to avoid more invasive procedures required for the latter. Two cases of metastatic carcinoid to the breast are presented with review of the literature.

The intrinsic antimicrobial activity of citric acid-coated manganese ferrite nanoparticles is enhanced after conjugation with the antifungal peptide Cm-p5.

Diseases caused by bacterial and fungal pathogens are among the major health problems in the world. Newer antimicrobial therapies based on novel molecules urgently need to be developed, and this includes the antimicrobial peptides. In spite of the potential of antimicrobial peptides, very few of them were able to be successfully developed into therapeutics. The major problems they present are molecule stability, toxicity in host cells, and production costs. A novel strategy to overcome these obstacles is conjugation to nanomaterial preparations. The antimicrobial activity of different types of nanoparticles has been previously demonstrated. Specifically, magnetic nanoparticles have been widely studied in biomedicine due to their physicochemical properties. The citric acid-modified manganese ferrite nanoparticles used in this study were characterized by high-resolution transmission electron microscopy, which confirmed the formation of nanocrystals of approximately 5 nm diameter. These nanoparticles were able to inhibit Candida albicans growth in vitro. The minimal inhibitory concentration was 250 µg/mL. However, the nanoparticles were not capable of inhibiting Gram-negative bacteria (Escherichia coli) or Gram-positive bacteria (Staphylococcus aureus). Finally, an antifungal peptide (Cm-p5) from the sea animal Cenchritis muricatus (Gastropoda: Littorinidae) was conjugated to the modified manganese ferrite nanoparticles. The antifungal activity of the conjugated nanoparticles was higher than their bulk counterparts, showing a minimal inhibitory concentration of 100 µg/mL. This conjugate proved to be nontoxic to a macrophage cell line at concentrations that showed antimicrobial activity.