Reimagining Flow Cytometric Cell Sorting.

In this review, a brief history of this unrivaled technology, flow cytometry, is provided, highlighting its past and present advances, with particular focus on "flow cell" technologies. Flow cytometry has truly revolutionized high-throughput single cell analysis, which has tremendous implications, from laboratory to the clinic. This technology embodies what is truly referred to as cross fertile research, merging the physical with the life sciences. This review introduces the recent notable advancements in flow cell technology. This advancement sees the complete removal of liquid sheath flow, which has advanced the technology with the possibility of both the reduction in its foot print, while also simplifying the flow cells explored in cytometry. Interestingly, the novel sheathless flow cell technology demonstrated herein has the flexibility for handling both heterogeneous cell populations and whole organisms, thus demonstrating a versatile flow cell technology for both flow cytometry and fluorescent-activated cell sorting.

The development of methods for primary mast cells in vitro and ex vivo: An historical review.

Mast cells (MCs) are tissue-based stationary effector cells that form the immune system's first-line defense against various challenges. They are developed from the bone marrow-derived progenitors to complete their differentiation and maturation in the tissues where they eventually establish residence. MCs have been implicated in many diseases, such as allergy, parasitic infection, and neoplastic disorders. Immortalized MC lines, such as RBL-2H3, HMC-1, and LAD-2, are useful for investigating the biological functions of MC only to some extents due to the restriction of degranulation evaluation, in vivo injection and other factors. Over the past few decades, technologies for acquiring primarily MCs have been continually optimized, and novel protocols have been proposed. However, no relevant publications have analyzed and summarized these techniques. In this review, the classical approaches for extracting MCs are generalized, and new methods with potential values are introduced. We also evaluate the advantages and applicability of diverse MC models. Since MCs exhibit substantial plasticity and functional diversity due to different origins, it is both necessary and urgent to select a reliable and suitable source of MCs for a particular study.

Enzyme Development for Human Islet Isolation: Five Decades of Progress or Stagnation?

In comparison to procedures used for the separation of individual cell types from other organs, the process of human pancreatic islet isolation aims to digest the pancreatic exocrine matrix completely without dispersing the individual cells within the endocrine cell cluster. This objective is unique within the field of tissue separation, and outlines the challenge of islet isolation to balance two opposing priorities. Although significant progress has been made in the characterization and production of enzyme blends for islet isolation, there are still numerous areas which require improvement. The ultimate goal of enzyme production, namely the routine production of a consistent and standardized enzyme blend, has still not been realized. This seems to be mainly the result of a lack of detailed knowledge regarding the structure of the pancreatic extracellular matrix and the synergistic interplay between collagenase and different supplementary proteases during the degradation of the extracellular matrix. Furthermore, the activation of intrinsic proteolytic enzymes produced by the pancreatic acinar cells, also impacts on the chance of a successful outcome of human islet isolation. This overview discusses the challenges of pancreatic enzymatic digestion during human islet isolation, and outlines the developments in this field over the past 5 decades.

Purification of basophils from peripheral human blood.

The purification of basophils from peripheral blood has represented a formidable challenge for researchers since they were discovered by Paul Ehrlich in 1879. From the first published attempts in the late 1960s, it took half a century to develop robust protocols able to provide sufficient numbers of pure, functionally unimpaired basophils. The existing protocols for basophil purification exploit those properties of basophils which distinguish them from other cell types such as their localization in blood, density, and the presence or absence of surface markers. Purification techniques have been used in various combinations and variations to achieve a common goal in mind: to obtain a pure population of human basophils in sufficient numbers for downstream studies. The arduous way leading up to the modern protocols is summarized in this historical retrospective. A fast protocol for purification of basophils to near homogeneity is also described.

[Urgency and improvement of sanitary and helminthological techniques of soil investigation].

From its inception, sanitary parasitology aimed at protecting the health of the population. But the procedures for sanitary and parasitological studies were not always so simple and effective as it was necessary. This article presents an analysis of the evolution of helminthological knowledge and the methods of soil investigation.

Leukocyte transfusion and the development of the continuous-flow blood cell separator.

The treatment of anemia and thrombocytopenia with allogeneic cell transfusions is an effective and well-developed technology. However, leukocyte replacement transfusion has been frustrated by the physiology of the leukocytes. To achieve effective leukocyte replacement, the continuous-flow centrifugal blood cell separator was developed, and it soon proved to be an important instrument for separation, collection, and transfusion of all the components of the blood. Thus, the continuous-flow centrifugal blood cell separator has become an important instrument in the science of blood collection and transfusion.

The birth of the osteoclast.

Thirty-five years ago it had become clear that the osteoclast was not a bone cell but an immigrant into bone, derived from the hemopoietic system. Among hemopoietic cells, mononuclear phagocytes seemed the most likely precursors. However, for the progeny of wandering cells such as those to achieve nonrandom localization implies control by the local bone cells (cells of the osteoblastic lineage). To test this idea, we extracted osteoclasts from bone and observed their behavior in culture. We noted that calcitonin induced a striking shape change, which reflected suppression of cytoplasmic motility. Because bone resorption is likely to depend on motile processes, we used this response to infer the regulation of osteoclasts by systemic and local hormones and osteoblastic cells. We went on to provide direct evidence for the predominantly osteoblastic regulation of osteoclasts by measuring the ability of isolated osteoclasts to resorb the surface of bone slices.

Beginning of pancreatic islet isolation by collagenase digestion (personal reminiscences).

The beginning of pancreatic islet isolation by collagenase digestion is described in the form of personal account.