Ultrastructural Modification of the Plasma Membrane in HUT 102 Lymphoblasts by Long-Wave Ultraviolet Light, Psoralen, and PUVA

Ultrastructural alterations of the plasma membrane in HUT 102 lymphoblasts were assessed after a 2-h interaction with a suprapharmacologic (15 μ/m1) concentration of 8-MOP, 2-h irradiation with UVA (2.1 mW/cm2), and the exposure of the HUT 102 cells to PUVA under the same conditions.The dark reaction of HUT cells with 8-MOP resulted in the disappearance of microvilli, the emergence of plasma-membrane-associated spherical bodies, formation of lamellar fungiform membrane evaginations, and, in approximately 1% of the cells, formation of uropods and cell capping. Except for uropod formation and cell capping, UVA has induced the same plasma-membrane alterations, and was more deleterious to structural cytoplasmic integrity than 8-MOP. Morphologic changes of the plasma membrane in PUVA- exposed cells tended to replicate structural alterations elicited independently during the dark reaction by suprapharmacologic 8-MOP concentrations. Partial retention of microvilli by cells after PUVA was the sole exception.In light of all available evidence we conclude that psoralen during the dark reactions interacts with plasma membrane lipids by as yet undisclosed mechanisms and that in addition to lipids, membrane proteins are also the primary target of the initial interaction of HUT 102 cells with psoralen during PUVA treatment

Carboxyl-modified single-wall carbon nanotubes improve bone tissue formation in vitro and repair in an in vivo rat model.

The clinical management of bone defects caused by trauma or nonunion fractures remains a challenge in orthopedic practice due to the poor integration and biocompatibility properties of the scaffold or implant material. In the current work, the osteogenic properties of carboxyl-modified single-walled carbon nanotubes (COOH-SWCNTs) were investigated in vivo and in vitro. When human preosteoblasts and murine embryonic stem cells were cultured on coverslips sprayed with COOH-SWCNTs, accelerated osteogenic differentiation was manifested by increased expression of classical bone marker genes and an increase in the secretion of osteocalcin, in addition to prior mineralization of the extracellular matrix. These results predicated COOH-SWCNTs' use to further promote osteogenic differentiation in vivo. In contrast, both cell lines had difficulties adhering to multi-walled carbon nanotube-based scaffolds, as shown by scanning electron microscopy. While a suspension of SWCNTs caused cytotoxicity in both cell lines at levels >20 μg/mL, these levels were never achieved by release from sprayed SWCNTs, warranting the approach taken. In vivo, human allografts formed by the combination of demineralized bone matrix or cartilage particles with SWCNTs were implanted into nude rats, and ectopic bone formation was analyzed. Histological analysis of both types of implants showed high permeability and pore connectivity of the carbon nanotube-soaked implants. Numerous vascularization channels appeared in the formed tissue, additional progenitor cells were recruited, and areas of de novo ossification were found 4 weeks post-implantation. Induction of the expression of bone-related genes and the presence of secreted osteopontin protein were also confirmed by quantitative polymerase chain reaction analysis and immunofluorescence, respectively. In summary, these results are in line with prior contributions that highlight the suitability of SWCNTs as scaffolds with high bone-inducing capabilities both in vitro and in vivo, confirming them as alternatives to current bone-repair therapies

Microscopic and Histochemical Manifestationsof Hyaline Cartilage Dynamics

Structure and function of hyaline cartilages has been the focus of many correlativestudies for over a hundred years. Much of what is known regarding dynamics and function of cartilage constituents has been derived or inferred from biochemical and electron microscopic investigations. Here we show that in conjunction with ultrastructural, and high-magnification transmission light and polarization microscopy, the well-developed histochemical methods are indispensable for the analysis of cartilage dynamics. Microscopically demonstrable aspects of cartilage dynamics include, but are not limited to, formation of the intracellular liquid crystals, phase transitions of the extracellular matrix and tubular connections between chondrocytes. The role of the interchondrocytic liquid crystals is considered in terms of the tensegrity hypothesis and non-apoptotic cell death. Phase transitions of the extracellular matrix are discussed in terms of self-alignment of chondrons, matrix guidance pathways and cartilage growth in the absence of mitosis. The possible role of nonenzymatic glycation reactions in cartilage dynamics is also reviewed

Storage and transplantation of bone marrow in the treatment of malignant diseases

The development of special methods of bone marrow transplantation, coupled with new knowledge in the area of donor‐recipient selection and the suppression of the secondary diseases, has generated renewed interest in allografting of bone marrow for a variety of diseases. The interest in marrow allotransplantation has overshadowed previously existing interest in autotransplantation despite the fact that autotransplantation has not met with serious side effects, such as GVH and secondary diseases. Sufficient evidence demonstrating the reliability of methods of short‐term and long‐term storage of human bone marrow has now been accumulated. It can be anticipated that reinfusion of bone marrow stored by these methods will result in uniform hematopoetic recovery of bone marrow suppressed by irradiation or chemotherapeutic agents. In cases of malignant diseases in anticipation of future needs, disease‐free marrow can be collected before the malignant process becomes generalized. Since bone marrow is best obtained under general anesthesia, routine bone marrow collection and storage from patients undergoing surgery for specific malignancies is suggested

Freezing of Human Bodies

New developments in the field of medical research sometimes go unnoticed and lie dormant for a number of years or are rapidly translated into clinical practice. At times, sound laboratory findings gain popularity outside of medical circles and, mainly through misinterpretation, attempts are made by the layman to translate the findings into practical applications. This seems to be the case with some aspects of cryobiology.Periodically, attention is given in the popular press to various organizations associated with the "cryonics" movement, which advocate freezing of dead human bodies rather than burying them in a customary fashion. The bodies are being frozen with a promise of an indefinite preservation, the procedure justified by a statement that, even if resuscitation from the frozen state will not be possible in the future, there is nothing to be lost by subjecting a body to freezing rather than burial. The point about "nothing to lose

Unidentified Reticuloendothelial Cell Storage Disease

Abstract 1. An abnormal cell of probably reticuloendothelial origin with prominent cytoplasmic granules was observed in the bone marrow, liver and a lymph node of an adult white female with incidentally discovered, asymptomatic hepatosplenomegaly. 2. Histochemical studies revealed the granules to consist of a chemical complex which contained bound lipid and protein. 3. The cells differed from those of Gaucher’s disease, Niemann-Pick’s disease and other storage diseases. The significance of these cells remains unknown

Injury of human polymorphonuclear granulocytes frozen in the presence of cryoprotective agents

The granulocyte suspensions of human granulocytes from the peripheral blood were frozen in the presence of 7.5% dimethylsulfoxide (DMSO) at rates of 1 °C/min until temperatures of −30 °C were reached. The cells were then frozen at a rate of −10-(−)60 °C/min. They were then stored in liquid nitrogen refrigerators from 10 min to 1 1 2 years. Thawed granulocytes did not regain motility even on prolonged incubation and developed homogenous large cytoplasmic bubbles. However, the cells were able to selectively incorporate neutral red granules into the cytoplasm. The cells eventually disintegrated when incubated up to 24 hr. Examination of stained cells showed disruption of the nuclear chromatin. Cells stained with toluidine blue at controlled pH observed under water, showed reversal in normal tinctorial properties of the cells. The nucleus failed to stain, and the cytoplasm stained strongly basophilic. The cytoplasm bubbles showed metachromasia. Cells stained with Feulgen's reaction showed the presence of Feulgen-positive material in the cytoplasm. PAS reaction showed PAS-positive granules in the cytoplasm. Staining for protein revealed strong reaction in the cytoplasm. The cytoplasmic bubbles did not stain. These observations suggest that human PMN cannot withstand freezing in the presence of DMSO, and that the primary site of cryoinjury is the nucleus, and not the cytoplasm