Van Leeuwenhoek Research Articles

Hematological cytomorphology: Where we are.

The manuscript discusses the historical evolution of observing blood cell morphology under an optical microscope, from the earliest microscopes in the 17th century to the modern digital era, highlighting key advancements and contributions in the field. Blood has historically held symbolic importance in various cultures, with early medical observations dating back to Hippocrates and Galeno. The discovery of cells and subsequent advancements in microscopy by scientists like Hooke and van Leeuwenhoek paved the way for understanding blood cell morphology. Influential figures such as Hewson, Donné, and Ehrlich followed. Diagnostic cytology evolved from manual cell counting to the development of automated hematological systems. Automated complete blood counting came to support microscopic examination in diagnosing hematological disorders. Morphology is crucial in predicting disease outcomes and guiding treatment decisions, particularly hematological neoplasms. The introduction of flow cytometry and its integration with traditional morphological analysis and the new cytogenetic and molecular techniques revolutionized the classification and prognostication of hematologic disorders. Digital microscopy has emerged as a powerful tool in recent years, offering rapid acquisition and sharing of blood cell images. Integrating Artificial Intelligence with digital microscopy has further enhanced morphological analysis, improving diagnostic efficiency. We also discuss the prospects of AI in pre-classifying blood cells in bone marrow aspirate samples, potentially revolutionizing diagnostic pathways for hematologic diseases. Overall, the manuscript provides a comprehensive overview of the historical development, clinical significance and technological advancements in observing blood cell morphology, underscoring its continued relevance in modern hematology practice.

Critical Focus | What Could the First Microscopists See?

Excerpt: We all remember key dates. Top of the list? It’s July 4, 1776, when the Declaration of Independence was signed so the U.S. became a nation in its own right and set the time for a huge annual party of fun, feasting, and fireworks. Here’s another for you: September 7, 1674. It’s the day science met the microbe. On that date, Antony van Leeuwenhoek, the draper of Delft, penned a letter to London. He told how he’d recently returned from a trip by boat across a nearby lake and had collected a small glass bottle of the greenish growths that he saw in the water. Leeuwenhoek had been experimenting with home-made single-lensed microscopes and had taken a close look at his lakewater samples. What he saw revolutionized the world of science, for he was astonished to see a myriad tiny microbes swimming about. In that instant, our modern era of bioscience was born. Yet (to quote cell biologist Nick Lane in a recent video for the Royal Society) scientists still do not know what Leeuwenhoek saw. After reading this article, they will.

Microbial Primer: In vivo biofilm.

In this primer on biofilms and their role in infections, we trace the historical roots of microbial understanding from Van Leeuwenhoek's observations to Bill Costerton's groundbreaking work, which solidified biofilms' significance in infections. In vivo biofilm research, investigating patient samples and utilizing diverse host models, has yielded invaluable insights into these complex microbial communities. However, it comes with several challenges, particularly regarding replicating biofilm infections accurately in the laboratory. In vivo biofilm analyses involve various techniques, revealing biofilm architecture, composition, and behaviour, while gaps in knowledge persist regarding infection initiation and source, diversity, and the Infectious Microenvironment (IME). Ultimately, the study of biofilms in infections remains a dynamic and evolving field poised to transform our approach to combat biofilm-associated diseases.

Global research landscape on two coumarin derivatives: A scientometric study of trends and innovations from 1990 to 2022

Daphnetin(7,8-dihydroxycoumarin) and esculin (6,7-dihydroxycoumarin-β-D-glucopyranoside) are natural coumarins that have gained increasing research attention over the years due to their therapeutic applications in a wide range of human ailments. This study assessed the current research status and future research trends of daphnetin and esculin through bibliometric analysis. Relevant articles on these compounds published between 1990 and 2022 were identified in the Web of Science and Scopus databases. “Daphnetin”* or “Esculin”* were used as the search terms to retrieve articles in the “Topic” field of both databases, and RStudio and VOSviewer were used for bibliometric analysis and visualization of meta-data from the retrieved documents. A total of 2172 publications on both compounds were identified. Research outputs on daphnetin and esculin have increased steadily over the years with an annual growth rate of 4.46%. China (576 articles, 28.2%) and USA (198 articles, 9.7%) are the top countries researching on daphnetin and esculin with China being the main country in the international cooperation network. International Journal of Systematic and Evolutionary Microbiology (215 articles), Journal of Clinical Microbiology (71 articles), International Journal of Systematic Bacteriology (29 articles), Archives of Microbiology (24 articles), and Antonie Van Leeuwenhoek (21 articles) are the top five journals publishing articles on these compounds. The most common research topics for both compounds were their biological activities, including anti-microbial, antibiotic resistance, anticancer, anti-inflammatory and antioxidant effects. With an average citation of 21.83 per document, citation analysis revealed that both compounds have been cited a considerable number of times, indicating their significance in the scientific community. Taken together, findings from this review provide insights into the status and trends of daphnetin and esculin research, thus highlighting their increasing interest and potential applications in the medical field.

Memoria e preformazione: analogia tra processo cognitivo e metamorfosi del vivente nel pensiero di Leibniz

It is well known how Leibniz turned his attention to a large number of domains in an attempt to demonstrate the universal interconnectedness of things. This essay aims to show the relationship between two areas of knowledge studied by Leibniz: gnoseology and biology. In particular, there is a close correspondence between the doctrine of innate ideas and that of the organism. The former are in fact understood as the constitutive elements of a layered mind and can be brought to consciousness through reminiscence. In contrast to the Platonic tradition, innate ideas are not the trace of notions acquired in previous lives, but are the result of a metamorphosis of living organisms. This consideration leads precisely to the Leibniz’s conception of the organism, influenced by the contemporary microscopic observation of van Leeuwenhoek and Malpighi and by the discovery of ‘spermatic animals'. In this sense, the idea of a pre-formed organism, subject to growth and contraction, is analogous to the peculiar conception of memory as a constitutive pre-configuration of the mind.

Squamous Cell Carcinoma Antigen in the Follow-up of Patients With Head and Neck Cancer.

to determine if the tumor marker squamous cell carcinoma antigen (SCC-Ag) observed over time may contribute to the early detection of recurrence, metastasis, and second primary tumors in the follow-up of patients with head and neck squamous cell carcinoma (HNSCC). A retrospective analysis of patients with HNSCC and at least one SCC-Ag measurement was conducted. Hazard ratios (HRs) were used to determine the correlation between SCC-Ag and an event. patients with HNSCC, treated in the Antoni van Leeuwenhoek Hospital in The Netherlands between 2010 and 2020 were used for the analysis. Data from 789 patients were used on event-free survival (EFS) with time-dependent Cox models. In addition to current (most recent) SCC-Ag (also dichotomized into high and low as done for clinical practice), average SCC-Ag and change between SCC-Ag measurements (delta SCC-Ag) were considered, using restricted cubic splines to explore nonlinear relationships. Dichotomized SCC-Ag values (HR = 3.01, 95% confidence interval [CI]: 2.17-4.18) and the delta SCC-Ag (HR = 1.15, 95% CI: 1.07-1.22) predicted EFS better than models using the cumulative average or current value of SCC-Ag, also after adjusting for tumor site, stage, age, and gender. A strong association was observed when using delta SCC-Ag as a linear predictor in the subgroup of oropharynx patients (HR = 4.88, 95% CI: 2.71-8.79). Dichotomized and delta SCC-Ag values can be important markers for EFS, during the follow-up of patients treated for HNSCC. These results were more evident in patients with oropharyngeal cancer.

From the inside out: understanding the gut-heart connection.

The gut microbiome was first termed as 'Animalcules' by Antonie van Leeuwenhoek in the 17th century. The diverse composition and complex interactions of gut microbes are essential for good human health. They play a crucial role in inflammation, which by itself leads to the development of cardiovascular diseases. Although the mechanisms are not fully understood, it has been studied that the gut microbiota produce several bioactive metabolites impacting cardiovascular health mainly through TMAO pathway, SCFA pathway and bile acid pathway. Moreover, studies have found that using dietary interventions like high fiber diet and probiotics to re-establish a healthy equilibrium show promising results on improving cardiovascular health and thus, could be potentially used for prevention and management of cardiovascular diseases.

Ball Lens‐Assisted Cellphone Imaging with Submicron Resolution

AbstractOne of the most significant developments in life sciences—the discovery of bacteria and protists—was accomplished by Antoni van Leeuwenhoek in the 17th century using a single ball lens microscope. It is shown that the full potential of single lens designs can be realized in a contact mode of imaging by ball lenses with a refractive index of n ≈ 2, suitable for developing compact cellphone‐based microscopes. The quality of imaging is comparable to basic compound microscopes, but with a narrower field‐of‐view, and is demonstrated for various biomedical samples. The maximal magnification (M > 50) with the highest resolution (≈0.66 µm at λ = 589 nm) is achieved for imaging of nanoplasmonic structures by ball lenses made from LASFN35 glass, the index of which is tuned near n = 2 using chromatic dispersion. Due to limitations of geometrical optics, the imaging theory is developed based on an exact numerical solution of the Maxwell equations, including spherical aberration and the nearfield coupling of a point source. The modeling is performed using multiscale analysis: from the field propagation inside ball lenses with diameters 30 < D/λ < 4000 to the formation of the diffracted field at distances of ≈105 λ. It is shown that such imaging enables the transition from pixel‐ to diffraction‐limited resolution in cellphone microscopy.

Prevention and treatment of tuberculosis before two great discoveries of the 20th century: the Bacillus Calmette-Guérin vaccine and streptomycin

Introduction and Purpose. Fundamental milestone in fight against tuberculosis is the invention of the effective vaccine, but before Anthony van Leeuwenhoek was the first to observe the bacteria, which opened the door to the first vaccinations in the 19th century. Medicine had battled against infectious diseases in different ways. Some methods can be perceived as a kind of primitive vaccines, which couldn’t, however, considerably affect a decrease in the epidemic range, due to their uncommon use and limited effectiveness. The aim of this paper is to analyze the history of tuberculosis and the role of Poland in the fight against it.
 Materials and methods. PubMed database was used for review of the literature. The following phrases were searched in English: “tuberculosis”, “vaccination”, “BCG vaccine”, “sanatorium”.
 Description of the state of knowledge. Poland played an important role in the fight against tuberculosis. It was in the laboratory of Polish pharmacist, where Koch discovered its etiological factor. In the territory of Poland there are prototypes of modern sanatoria for tuberculosis patients. Article also presents old and modern methods of tuberculosis treatment, as the use of specific climatic conditions, which resulted in developing health-resort treatment. A breakthrough in the methods used was the discovery of streptomycin in the middle of the 20th century, which led to the development of pharmacological treatment, nowadays involving the administration of proper combinations of drugs.
 Summary. The increasingly strong anti-vaccine movement is slowly destroying what people have been fighting for the centuries. It is worth recalling how we reached milestones in this fight and why immunization is so important for all societies.

Van Leeuwenhoek - the film: remaking memory in Dutch science cinema 1925-c.1960.

This paper examines how the production, content and reception of the film Antony van Leeuwenhoek (1924) influenced the historical framing of science. The film features microcinematography by the pioneering Dutch filmmaker Jan Cornelis Mol (1891-1954), and was part of a dynamic process of commemorating seventeenth-century microscopy and bacteriology through an early instance of visual re-creation - a new way of using scientific material heritage, and of enabling audiences to supposedly observe the world of microscopic organisms in just the same way as the Dutch scientist Antoni van Leeuwenhoek (1632-1723) had observed them for himself. Knowledge transfer concerning material culture, around both historical and contemporary instruments, was the determining factor in the microcinematography practices applied in this film. The production and experience of the film also mirrored the seventeenth-century process of experimentation, playing with optics, and visualizing an entirely new and unknown world. Unlike other biographical science films of the 1920s, Antony van Leeuwenhoek featured abstract depictions of time and movement that allowed the audience to connect the history of science with microcinematography, contributing to the memory of Van Leeuwenhoek's work as the origins of bacteriology in the process.

Leeuwenhoek

“Among all the marvels I have discovered in nature, these are the most marvelous of all.”So goes a quote from Anton van Leeuwenhoek referring to the animalcules he observed through the earliest of microscopes. He was looking at a drop of rainwater that had collected outside his home and had been sitting there for two days. His animalcules, of course, are microbes, but he did not know that term.A video from Journey to the Microcosmos called Leeuwenhoek: The First Master of Microscopes takes the viewer through the fascinating early days of Leeuwenhoek’s work and discoveries. Most people credit Robert Hooke as the father of the microscope, but it was actually Leeuwenhoek who provided the basis of Hooke’s work. Leeuwenhoek was known to be an avid writer, publishing many works documenting his journeys into the microcosmos.Leeuwenhoek started his career as a draper, one who sells cloth. His work with the microscope started as just a hobby. He taught himself how to grind lenses, which he then used as tools to look at those objects that could not be seen with the naked eye. His early microscopes were far better than those of his contemporaries, having images that were better magnified and clearer.While Leeuwenhoek wrote his material in his native Dutch, other scientists have done their best to translate it. One such interesting translation describes Leeuwenhoek’s analysis of his poop. He describes its consistency, but more importantly, he talks about the microbes (or animalcules) he found within it. While he had no specific names for these organisms as we do today, from the descriptions he provided, it has been possible to determine to which organisms he was referring.Many people tried to replicate Leeuwenhoek’s work, but failed. While he published a lot, he did not leave behind any documentation of his methods of building his microscopes or observing the organisms. It was not until Robert Hooke that the microorganisms Leeuwenhoek had seen were observed again. Hooke did share his methods and even demonstrated them for others, validating the observations Leeuwenhoek had made.The video shows footage that matches the narration, showing various microscopic images of the organisms Leeuwenhoek saw. The footage provides the viewer with upward of 200× magnification, showing the organisms in very high detail. These images, of course, are far better than anything Leeuwenhoek saw, but they give the viewer the general idea of what he was seeing. The narration is pleasant and informative.Leeuwenhoek: The First Master of Microscopes is appropriate for all students in grades 5 and up. It would be a great way to introduce the microscope to younger students, and diversity of life to older ones. Advanced students could use the images in the video as the basis for individual research projects, trying to find similar organisms in ponds or rainwater.

International Microorganism Day: facilitating global outreach events using a decentralized model.

On 17 September 1683, Antonie van Leeuwenhoek, a Dutch merchant who lacked formal education and fortune, wrote a letter to the Royal Society of London describing for the first time a single-celled organism. As a tribute to this revolutionary discovery, the Portuguese Society of Microbiology with the support of the Federation of European Microbiological Societies in 2017, designated this day as International Microorganism Day (IMD), a day aiming to raise awareness about the wonderful world of microbes. Six years after the establishment of IMD, the knowledge of microbiology outreach around this celebration has expanded greatly, with 5 years of in-person and 2 years of online events. The peak of these commemorations was in 2023, with 63 parallel outreach events and more than 5000 attendees, most of which were children, and young adults. While these in-person events were occurring in the month of September, the #InternationalMicroorganismDay hashtag reached nearly 2.3 million people online, reflecting the number of users who have seen a post containing this hashtag on social media. Using a decentralized model to facilitate 63 grass-roots teams to organize events locally, IMD achieved global representation both online and offline. This paper presents details behind the organization and data on the international impact of the IMD 2022 and 2023 events, outlines plans to expand reach to more countries and audiences, and encourages readers to participate with their own events in future IMD editions so that global impact can be expanded even further.

Editorial | Another Leeuwenhoek Comes to Light

Antony van Leeuwenhoek's handmade microscopes -- those simple, single-lens instruments small enough to rest in the palm of your hand -- continue to intrigue and fetch large sums at auction. The Dutch microbiologist is known to have left 247 microscopes when he died in 1723. And now, one more has surfaced.

Advances in Microscopy Tech Offer Better Views.

Microscopes have come a very long way since the 1600s when Henry Power, Robert Hooke, and Anton van Leeuwenhoek began publishing the first views of plant cells and bacteria. The major inventions of contrast, electron, and scanning tunneling microscopes didn't arrive until the 20th century, and the men behind them all earned Nobel Prizes in physics for their efforts. Today, innovations in microscopy are coming at a fast and furious rate with new technologies providing first-time views and information about biological structures and activity, and opening up new avenues for disease therapies.

TRANSFORMED CELL - THE UNUSUAL SUCCESSION OF A USUAL CELL

After the first observations of life under the microscope, it took almost two centuries of research before the idea that all living things are composed of cells or their products was speculated. The development of the microscope was a requirement for the discovery of cells. In 1673, the Dutch botanist, Anton van Leeuwenhoek, reported seeing a myriad of microscopic "animalcules" in water. Over several decades, knowledge about the structure and functions of the cell has progressed tremendously due to the advancement in various techniques like next generation sequencing, and genome wide analysis. Cancers are generated from normal cells by random karyotypic rearrangements. Immortality is a common characteristic of cancers, but its origin and purpose are still unclear. Since such rearrangements disturb long-established mitosis genes, cancer karyotypes vary instinctively but are stabilized perpetually by clonal selections for autonomy. The differentiation stage of tumors is a vital aspect in the histopathological classification of solid malignancies, strongly associated with tumor behavior, as an immature tumor is more aggressive than the more differentiated counterpart. The central focus in these events is the cell that undergoes a series of morphological and biochemical changes in course of its transition from normal to a transformed tumor cell; thus acquiring typical characteristics which aids in the process of progression. In this review an attempt has been made to enlighten upon the unusual behavior of a normal cell in transition.

On the Origin and Evolution of Sperm Cells

Sperm cells have intrigued biologists since they were first observed nearly 350 years ago by Antonie van Leeuwenhoek and Johan Ham [...].

Surgical site complications of isolated salvage neck dissection post-radiotherapy and post-chemoradiotherapy – A cohort analysis (1997–2017)

IntroductionThis study aims to quantify surgical site complications (SSC) after isolated salvage neck dissection (ND) compared with primary ND. Patients and methodsBetween 1997 and 2017 in the Netherlands Cancer Institute - Antoni van Leeuwenhoek, a total of 323 isolated NDs were performed in 308 patients: primary ND (n = 144), post-radiotherapy (RT) ND (n = 53) and post-chemoradiotherapy (CRT) ND (n = 126). Patient, tumor and therapy characteristics were recorded. SSCs were scored according to the Clavien-Dindo Classification (CDC). Results101 NDs (31%) were complicated by at least one SSC. In total, 189 different SSCs occurred. Translated to CDC, 45 complications were grade 2, 25 grade 3a and 31 grade 3b. No significant difference in occurrence of SSC (CDC >1) was found between all groups. However, post-CRT, selective (SND) and modified radical ND and radical ND (MRND/RND) (p = 0.005), resection of sternocleidomastoid muscle (SCM) (p = 0.039) and duration of super selective ND surgery (p = 0.048) were significantly associated with more SSC. SCM muscle removal was associated with more surgical site infection (p = 0.045) and necrosis (p = 0.036). From week 10 post-RT/CRT, no difference in complication frequency with primary ND was seen. ConclusionPost-CRT SND, MRND/RND and SCM muscle resection were associated with an increased incidence of SSCs. If oncologically possible, limit the extent of ND and when an MRND is inevitable, preserve the SCM muscle for optimal prevention of SSC. Concerning SSC, optimal timing of salvage ND is minimal 10 weeks after RT/CRT.

Seeing what Leeuwenhoek saw

Friday 26 August 2023 marks the tercentenary of the death of Antony van Leeuwenhoek, the founder of microbiology. After three centuries, you might think that everything about his life and work has long since been discovered, but mysteries remain.

Large-scale phylogenetic analysis provides insights into the diversification and evolution of sessilid peritrich ciliates (Protista: Ciliophora).

The Peritrichia is a speciose and morphologically distinctive assemblage of ciliated protists that was first observed by Antonie van Leeuwenhoek over 340 years ago. In the last two decades, the phylogenetic relationships of this group have been increasingly debated as morphological and molecular analyses have generated contrasting conclusions, mainly owing to limited sampling. In the present study, we performed expanded phylogenetic analyses of 152 sessilid peritrichs collected from 14 different provinces of China and 141 SSU rDNA peritrich sequences from GenBank. The results of the analyses revealed new divergent relationships between and within major clades that challenge the morphological classification of this group including, (1) the recovery of four major phylogenetically divergent clades in the monophyletic order Sessilida, (2) aboral structures such as the stalk and spasmoneme were evolutionary labile, (3) the stalk or/and spasmoneme was lost in each divergent clade indicating that parallel evolution occurred in sessilid peritrichs and (4) the life cycle and habit drive the diversity of aboral structures as well as diversification and evolution in peritrichs.

Why isn't each cell its own cell type? Diminishing returns of increasing cell type diversity can explain cell type allometry.

Since the discovery of cells by Robert Hooke and Antoni van Leeuwenhoek in the 17th century, thousands of different cell types have been identified, most recently by sequencing-based single-cell profiling techniques. Yet, for many organisms we still do not know, how many different cell types they are precisely composed of. A recent survey of experimental data, using mostly morphology as a proxy for cell type, revealed allometric scaling of cell type diversity with organism size. Here, I argue from an evolutionary fitness perspective and suggest that three simple assumptions can explain the observed scaling: Evolving a new cell type has, 1. a fitness cost that increases with organism size, 2. a fitness benefit that also increases with organism size but 3. diminishes exponentially with the number of existing cell types. I will show that these assumptions result in a quantitative model that fits the observed cell type numbers across organisms of all size and explains why we should not expect isometric scaling.