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We describe a new quantitative fluorimetric assay for phagocytosis of bacteria. A suspension of fluorescein-labelled bacteria (Micrococcus lysodeikticus) is mixed and incubated with phagocytes. After fixation with paraformaldehyde, the excess non-phagocytosed and adsorbed bacteria are lysed with a solution of lysozyme in phosphate-buffered saline. After washing of the phagocytes. the fluorescence of those that have ingested the labelled bacteria is measured with a spectrofluorimeter. We report results obtained with different types of phagocytes which show that this method allows sensitivity, saturation and kinetic studies and the calculation of a phagocytic index. [ABSTRACT FROM AUTHOR]

The increasing need for tissue substitutes in reconstructive surgery spurs the development of engineering methods suited for clinical applications. Cell culture and tissue production traditionally require the use of fetal bovine serum (FBS) which is associated with various complications especially from a translational perspective. Using the self-assembly approach of tissue engineering, we hypothesized that all important parameters of tissue reconstruction can be maintained in a production system devoid of FBS from cell extraction to tissue reconstruction. We studied two commercially available serum-free medium (SFM) and xenogen-free serum-free medium (XSFM) for their impact on tissue reconstruction using human adipose-derived stem/stromal cells (ASCs) in comparison to serum-containing medium. Both media allowed higher ASC proliferation rates in primary cultures over five passages compared with 10% FBS supplemented medium while maintaining high expression of mesenchymal cell markers. For both media, we evaluated extracellular matrix production and deposition necessary to engineer manipulatable tissues using the self-assembly approach. Tissues produced in SFM exhibited a significantly increased thickness (up to 6.8-fold) compared with XSFM and FBS-containing medium. A detailed characterization of tissues produced under SFM conditions showed a substantial 50% reduction of production time without compromising key tissue features such as thickness, mechanical resistance and pro-angiogenic secretory capacities (plasminogen activator inhibitor 1, hepatocyte growth factor, vascular endothelial growth factor, angiopoietin-1) when compared to tissues produced in the control FBS-containing medium. Furthermore, we compared ASCs to the frequently used human dermal fibroblasts (DFs) in the SFM culture system. ASC-derived tissues displayed a 2.4-fold increased thickness compared to their DFs counterparts. In summary, we developed all-natural human substitutes using a production system compatible with clinical requirements. Under culture conditions devoid of bovine serum, the resulting engineered tissues displayed similar and even superior structural and functional properties over the classic FBS-containing culture conditions with a considerable 50% shortening of production time., (Creative Commons Attribution license.)

Background: Elective caesarean section is performed mainly under spinal anaesthesia using hyperbaric bupivacaine combined with opioids. Despite rapid onset, good quality anaesthesia, bupivacaine provides a long duration of motor block and is related to maternal hypotension. Current policies appeal for implementation of enhanced recovery procedures after caesarean section. Hyperbaric prilocaine is an intermediate-acting local anaesthetic known for its efficacy in ambulatory surgery. Evidence on the clinical relevance of intrathecal prilocaine use for caesarean section is currently lacking., Objectives: We aimed to investigate whether hyperbaric prilocaine would offer a shorter motor block and recovery than bupivacaine, when comparing equipotent doses. We also assessed the characteristics of sensory block, maternal haemodynamics and side effects for both mother and newborn., Design: Prospective, randomised, double-blind, controlled, two-centre, clinical trial., Setting: One university teaching hospital and one general teaching hospital in Brussels, Belgium., Patients: American Society of Anesthesiologists' physical status 2 parturients (n = 40) undergoing caesarean section under spinal anaesthesia., Interventions: Patients were randomly assigned to receive spinal anaesthesia using hyperbaric prilocaine 50 mg or hyperbaric bupivacaine 10 mg, both given with sufentanil 2.5 μg and morphine 100 μg. An epidural catheter was introduced as a backup in case of failure., Main Outcomes: The primary outcome was the motor block regression (modified Bromage scale 1 to 6). Secondary outcomes included sensory block characteristics, first unassisted ambulation, maternal side effects, newborns' parameters and overall satisfaction., Results: Median [IQR] motor block was significantly shorter in the hyperbaric prilocaine group (110 [104 to 150] min versus 175 [135 to 189] min, P = 0.001). First unassisted ambulation was achieved earlier after prilocaine (204.5 [177 to 246.5] min versus 314 [209.25 to 400] min, P = 0.007), and the incidence of maternal hypotension was significantly higher with bupivacaine (P = 0.033). No supplementary epidural analgesia was needed., Conclusion: Prilocaine provides shorter motor block, faster recovery and better haemodynamic stability than bupivacaine while offering equivalent surgical anaesthesia., Trial Registration: Clinicaltrials.gov: NCT02973048, EudraCT: 2016-003010-26., (Copyright © 2021 European Society of Anaesthesiology and Intensive Care. Unauthorized reproduction of this article is prohibited.)

Sixteen patients with aggressive primary testicular involvement were analyzed separately from a prospective multicenter series of 494 patients with stage I/II aggressive nonlymphoblastic lymphoma. The treatment strategy included 3 cycles of anthracycline-based chemotherapy followed by regional radiation therapy on inguinal, iliac, and para-aortic lymph nodes and central nervous system (CNS) prophylaxis by intrathecal chemotherapy and brain irradiation. Chemotherapy was stratified by age group. Patients aged 18-60 years received the Groupe Ouest Est d'Etude des Leucemies Aigues et Maladies du Sang (GOELAMS) 02 protocol: 3 monthly cycles of VCAP (vindesine 3 mg/m2 day 1, doxorubicin 80 mg/m2 day 2, cyclophosphamide 1500 mg/m2 day 2, and prednisone 80 mg/m2 days 1-5). Patients aged 61-75 years received the GOELAMS 03 protocol: 3 monthly cycles of VECP-Bleo (vindesine 3 mg/m2 day 1, epirubicin 60 mg/m2 day 1, cyclophosphamide 750 mg/m2 day 1, prednisone 50 mg/m2 days 1-7, and bleomycin 10 mg/m2 days 1 and 5). Sixteen patients had testicular involvement (3.3%). Median age was 62 years (range, 29-73 years). The histological subtypes were diffuse large-cell lymphoma in all cases. Ann Arbor stage was IEA in 11 patients, IEB in 3 patients, and IIEA in 2 patients. All patients achieved a complete response. One patient died from septic shock during the last course of chemotherapy. After a median follow-up period of 73.5 months, the probability of disease-free survival (DFS) and overall survival (OS) were 70% and 65%, respectively for all patients. Disease-free survival and OS were 66% and 83% in patients = 60 years of age, and 74% and 56% in patients > 60 years of age. Relapse occurred in extranodal sites in 4 cases and in abdominal lymph nodes in the last case. Relapse in the CNS occurred in only 1 patient and in the contralateral testis in 1 patient. We found no correlation between OS, DFS and extent of testicular involvement, Ann Arbor stage, International Prognostic Index score, or lactate dehydrogenase level. This is the first report of a prospective study in which treatment of testicular non-Hodgkin's lymphoma was precisely defined at diagnosis. Compared to other series, a combination of orchiectomy with 3 cycles of CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone)-derived chemotherapy, regional radiation therapy, and CNS prophylaxis seems to improve prognosis. The improvement in prognosis seemed to be due in part to irradiation, including the pelvic and lomboaortic lymphatic areas, and in part to CNS prophylaxis.

Dispase has been utilized to produce basal detachment of the epidermis of human skin biopsies and to study the consequences induced afterwards during incubations of the detached tissue. Spatial reorganization of the epidermis is observed under these conditions and is characterized by disappearance of the typical basal keratinocyte layer. Immunofluorescent labelings reveal upward migration of several cells exhibiting the basal phenotype between suprabasal differentiating keratinocytes and demonstrate progressive intracellular expression of hemidesmosomal components: the integrin alpha 6 beta 4 and two plaque components, the 230-kDa bullous pemphigoid antigen and HD1, a 500-kDa protein. Using electron microscopy and immunogold techniques, we demonstrate that the hemidesmosome-containing basal membrane domains enter the cell cytoplasm after detachment of the epidermal tissue. Partial recycling of internalized hemidesmosomal components is also suggested. Our findings illustrate the processing of released hemidesmosomes in detached basal keratinocytes and suggest some heterogeneity between basal cells migrating towards a suprabasal position and those remaining in the basal layer. These results suggest that the dispase-detached epidermis is a self-remodeling tissue in which basal keratinocytes' and tissue's polarities observed in the anchored epidermis are progressively changing.

The integrin alpha 6 beta 4 is polarized towards the basal side of basal keratinocytes and helps anchor these cells to the basement membrane components. We have found that cultured human epidermal keratinocytes, when detached from their culture substratum, as for grafting, using the enzyme dispase, rapidly internalize the basal membrane domains containing the integrin alpha 6 beta 4, while integrins of the very late antigen subtype remain on the cell surface. Detachment and incubation at 4 degrees C prevent this internalization, as well as the contraction of the detached sheet area. Subsequent incubation at 37 degrees C initializes this contraction and allows the basal integrin alpha 6 beta 4 to be internalized. We took advantage of this blockage to label upon detachment using immunogold techniques, the alpha 6 subunit present on the basal cell surface; then we studied its internalization with the electron microscope. This internalization pathway differs from classical receptor-mediated endocytosis, and intermediate filaments might possibly play a role in this process. Interestingly, 1 h after their internalization from the basal membrane, a third of the gold particles labeling the alpha 6 subunit was found between lateral membranes of basal cells, strongly suggesting that the integrin alpha 6 beta 4 can be partly recycled to the cell surface in these conditions.

The contribution of adhesion to an extracellular matrix in the polarized spatial organization of keratinocytes was studied in dispase-detached cultures stored as floating sheets. Proliferating and terminally differentiating cell populations were, therefore, localized on tissue sections by their DNA-synthesizing ability and involucrin immunostaining, respectively. A progressive reorganization was induced from superposed proliferating and differentiating layers into clusters exhibiting differentiating cells on the outside. Measurements of proliferation and terminal differentiation in detached cultures revealed the progressive disappearance of proliferating cells, followed by an increase in involucrin-positive cells. Attempts to block the spatial reorganization by the addition of components of the extracellular matrix remained unsuccessful. These results suggest that basal anchorage is responsible for the superposition of proliferating and differentiating cells in keratinocyte cultures. They afford new arguments for the induction of terminal differentiation in non-adhesive keratinocytes which exhibit a concomitant modification of cell shape.

Grafting of human cultured keratinocytes is a promising possibility for the treatment of large burned skin areas. However, during the preparation of cultures for grafting, a necessary step of detachment from culture substratum is performed by incubation with Dispase. In the present paper, we report studies performed to determine whether prolonged storage after detachment would have a detrimental effect on keratinocyte proliferation. Our results show that the number of bromodeoxyuridine-incorporating cells located in the basal layer of the culture gradually diminishes during storage of detached cultured epidermal keratinocyte sheets. Furthermore, the rate of [3H]thymidine incorporation in such detached cultures is also progressively reduced. These observations indicate that the detachment and storage of cultured epidermal keratinocyte sheets for grafting impedes their cell proliferation capacity, as revealed by DNA-synthesis measurements.

An immunogold method in Terasaki plates is described which allows accurate and sensitive visualization of the binding of monoclonal antibodies to cell surface antigens and is suitable for large scale screening. Monolayers of fixed cells are prepared in the wells. The binding of monoclonal antibodies is detected by a protein A gold complex. The cell-bound gold can be visualized by either optical or transmission electron microscopy. The results obtained with various monoclonal antibodies are presented.

Peritoneal rat macrophages and rabbit polymorphonuclear leukocytes were obtained after thioglycollate or glycogen stimulation. Optimal conditions for phagocytosis were determined by a recently developed quantitative fluorimetric assay. We studied by serial SEM micrographs macrophages and polymorphonuclear leukocytes incubated either in medium or in the presence of different types of phagocytic particles. We compared the morphological aspects of adsorption and phagocytic processes for opsonized microorganisms (Micrococcus lysodeikticus and Candida albicans) with these for inert beads of iron and metallic mercury. Without phagocytosis, in the presence of fresh homologous serum, we observed a progressive development of microvilli or lamellipodia in ruffles and by the end, hypertrophied ruffles appeared at one pole of the cell. We noted extremely well developed ruffles during phagocytosis of opsonized microorganisms. These were practically absent on the macrophages incubated with inert particles. The mean number of adsorbed particles is more elevated in the case of iron and metallic mercury beads than for microorganisms. The rate of ingestion of inert particles was considerably higher than for microorganisms even when they were opsonized. In conclusion, at all stages of the phagocytic process, we observe different morphological features of the macrophages depending on the nature of the phagocytosed particles.