Density Of Labeled Cells Research Articles

Tumor-infiltrating immune cells as potential biomarkers predicting response to treatment and survival in patients with metastatic melanoma receiving ipilimumab therapy.

Monoclonal antibodies targeting immune checkpoints are gaining ground in the treatment of melanoma and other cancers, and considerable effort is made to identify biomarkers predicting the efficacy of these therapies. Our retrospective study was performed on surgical tissue samples (52 lymph nodes and 34 cutaneous/subcutaneous metastases) from 30 patients with metastatic melanoma treated with ipilimumab. Using a panel of 11 antibodies against different immune cell types, intratumoral immune cell densities were determined and evaluated in relation to response to ipilimumab treatment and disease outcome. For most markers studied, median immune cell densities were at least two times higher in lymph node metastases compared to skin/subcutaneous ones; therefore, the prognostic and predictive associations of immune cell infiltration were evaluated separately in the two groups of metastases as well as in all samples as a whole. Higher prevalence of several immune cell types was seen in lymph node metastases of the responders compared to non-responders, particularly FOXP3+ cells and CD8+ T lymphocytes. In subcutaneous or cutaneous metastases, on the other hand, significant difference could be observed only in the case of CD16 and CD68. Associations of labeled cell densities with survival were also found for most cell types studied in nodal metastases, and for CD16+ and CD68+ cells in skin/s.c. metastatic cases. Our results corroborate the previous findings suggesting an association between an immunologically active tumor microenvironment and response to ipilimumab treatment, and propose new potential biomarkers for predicting treatment efficacy and disease outcome.

Connectivity of somatosensory cortical area 1 forms an anatomical substrate for the emergence of multifinger receptive fields and complex feature selectivity in the squirrel monkey (Saimiri sciureus)

Converging evidence shows that interaction of digit-specific input, which is required to form global tactile percepts, begins as early as area 3b in the primary somatosensory cortex with the involvement of intrinsic lateral connections. How tactile processing is further elaborated in area 1, the next stage of the somatosensory cortical hierarchy, is less understood. This question was investigated by studying the tangential distribution of intrinsic and interareal connections of finger representations of area 1. Retrogradely labeled cell densities and anterogradely labeled fibers and terminal patches were plotted and quantified with respect to the hand representation by combining tract tracing with electrophysiological mapping and intrinsic signal optical imaging in somatosensory areas. Intrinsic connections of distal finger pad representations of area 1 spanned the representation of multiple digits indicating strong cross-digit connectivity. Area 1 distal finger pad regions also established high-density connections with homotopic regions of areas 3b and 2. Although similar to area 3b, connections of area 1 distributed more widely and covered a larger somatotopic representation including more proximal parts of the finger representations. The lateral connectivity pattern of area 1 is a suitable anatomical substrate of the emergence of multifinger receptive fields, complex feature selectivity, and invariant stimulus properties of the neurons.

Intrinsic horizontal connections process global tactile features in the primary somatosensory cortex: Neuroanatomical evidence

To understand manual tactile functions in primates, it is essential to explore the interactions between the finger pad representations in somatosensory cortex. To this end, we used optical imaging and electrophysiological mapping to guide neuroanatomical tracer injections into distal digit tip representations of Brodmann area 3b in the squirrel monkey. Retrogradely labeled cell densities and anterogradely labeled fibers and terminal patches in somatosensory areas were plotted and quantified with respect to tangential distribution. Within area 3b, reciprocal patchy distribution of anterograde and retrograde labeling spanned the representation of the distal pad of multiple digits, indicating strong cross-digit connectivity. Inter-areal connections revealed bundles of long-range fibers projecting anteroposteriorly, connecting area 3b with clusters of labeled neurons and terminal axon arborizations in area 1. Inter-areal linkage appeared to be largely confined to the representation of the injected finger. These findings provide the neuroanatomical basis for the interaction between distal finger pad representations observed by recent electrophysiological studies. We propose that intra-areal connectivity may be heavily involved in interdigit integration such as shape discrimination, whereas long-range inter-areal connections may subserve active touch in a digit-specific manner.

Areas of cat auditory cortex as defined by neurofilament proteins expressing SMI-32

The monoclonal antibody SMI-32 was used to characterize and distinguish individual areas of cat auditory cortex. SMI-32 labels non-phosphorylated epitopes on the high- and medium-molecular weight subunits of neurofilament proteins in cortical pyramidal cells and dendritic trees with the most robust immunoreactivity in layers III and V. Auditory areas with unique patterns of immunoreactivity included: primary auditory cortex (AI), second auditory cortex (AII), dorsal zone (DZ), posterior auditory field (PAF), ventral posterior auditory field (VPAF), ventral auditory field (VAF), temporal cortex (T), insular cortex (IN), anterior auditory field (AAF), and the auditory field of the anterior ectosylvian sulcus (fAES). Unique patterns of labeling intensity, soma shape, soma size, layers of immunoreactivity, laminar distribution of dendritic arbors, and labeled cell density were identified. Features that were consistent in all areas included: layers I and IV neurons are immunonegative; nearly all immunoreactive cells are pyramidal; and immunoreactive neurons are always present in layer V. To quantify the results, the numbers of labeled cells and dendrites, as well as cell diameter, were collected and used as tools for identifying and differentiating areas. Quantification of the labeling patterns also established profiles for ten auditory areas/layers and their degree of immunoreactivity. Areal borders delineated by SMI-32 were highly correlated with tonotopically-defined areal boundaries. Overall, SMI-32 immunoreactivity can delineate ten areas of cat auditory cortex and demarcate topographic borders. The ability to distinguish auditory areas with SMI-32 is valuable for the identification of auditory cerebral areas in electrophysiological, anatomical, and/or behavioral investigations.

Growing the Mandible: Role of the Periosteum and its Cells

Mandibular periosteum moves in the direction of new apposition. This displacement, usually termed "migration," is thought to involve the fibrous layer of periosteum, with the deeper osteogenic layer remaining at its original location except for its blood vessels. To assess whether periosteal displacement includes cells as well as matrix and whether the osteogenic layer has a role, a longitudinal study was undertaken. Young pigs (n = 10) were injected with a replication marker and killed 3 hr, 2 weeks, or 4 weeks later. Sections of the mandibular ramus were scored for labeled cell density. Some sections were double-labeled with lectin to identify blood vessels. Statistical differences were seen between but not within age groups. Three hours after labeling, the fibroblastic layer had sparse, evenly distributed replicating cells, whereas the osteogenic layer had numerous replicating cells, especially at the caudal border. At 2 and 4 weeks later, a decrease in labeled osteogenic layer cells was accompanied by an increase in labeled osteocytes. Zones of labeled osteocytes in these late-sacrifice groups were used to approximate the position of the ramal borders at the time of injection. Beyond these zones, in active growing sites, labeled cells were found not only in the fibrous layer but also in the osteogenic layer and in bone. Therefore, periosteal displacement does involve cells and is not restricted to the fibrous layer.

Generation of Dose-Volume Histograms Using Monte Carlo Simulations on a Multicellular Model in Radionuclide Therapy

An accurate calculation of the absorbed dose at the cellular level can lead to the optimization of the administered activity and the best clinical response in radionuclide therapy. This paper describes the implementation of dose-volume histograms (DVHs) for dosimetry at the cellular level in radionuclide therapy. The FOTELP code, based on Monte Carlo simulations of photon and electron transport, was used on a three-dimensional multicellular tumor model, which includes tumor morphometry and cell-labeling parameters. Differential and cumulated DVHs were generated for different radionuclides (Cu-67, I-131, Sm-153, Y-90, and Re-188) and labeled cell densities (10, 20, 40, 80, and 100%). DVHs were generated as a percentage of tumor cells in the function of a relative absorbed dose, defined as a cell-absorbed dose divided by an average tumor-absorbed dose. DVHs for high-energy beta emitters, such as Re-188 and Y- 90, were very close to the average tumor-absorbed dose. For low-energy beta emitters, such as Cu-67 and I-131, spectra showed that many cells absorbed a much lower dose than the average tumor-absorbed dose. Nonhomogeneity of the radionuclide distribution in tumor, presented by labeled cell density, had a greater influence on DVHs for low-energy beta emitters. Radionuclide therapy plans can be optimized using DVHs.

NADPH-diaphorase Histochemical Labeling Patterns in the Hippocampal Neuropil and Visual Cortical Neurons in Weaned Rats Reared during Lactation on Different Litter Sizes

Tissue distribution of nitric oxide-synthases was investigated in the rat hippocampus and visual cortex under nutritional changes induced by modification of the litter size. Young (30-45-days-old) rats, suckled in litters formed by 3, 6 or 12 pups (called small, medium and large litters, respectively), were studied by using nicotine-adenine-dinucleotide phosphate-diaphorase histochemistry (shortly, diaphorase), a simple and robust procedure to characterize tissue distribution of nitric oxide-synthases. We assessed morphometric features of the diaphorase-positive cells in visual cortex, and the neuropil histochemical activity in hippocampal CA1 and dentate gyrus using densitometry analysis. In the large-litter group, the labeled-cell density in white matter of area 17 was higher, as compared to the small-litter group. There was a clear trend, in the large-litter group, to lower values of soma area, dendritic field and branches per neuron, but the differences were not significant. Densitometry analysis of hippocampus revealed a significant increase in the relative neuropil histochemical activity of the dentate gyrus molecular layer in the larger litters, which may be associated to increased compensatory blood flow in the hippocampus. The pathophysiological mechanisms of the observed changes remain to be investigated.

Death of transcallosal neurons after close axotomy

The extent of cell death after axotomy may limit potential recovery after brain injury. We wished to determine the effect of axotomizing lesions on survival of transcallosally projecting cortical neurons. Transcallosal neurons were prelabeled by retrograde transport of the fluorescent dyes Fluoro-Gold and True Blue. A transcortical stab wound divided the field of labeled cortical cells into axotomized and unaxotomized groups. Little difference in labeled cell density was seen over the first few days after injury. Animals surviving at least 2 weeks after injury had clear loss of axotomized neurons. By 1 month after injury, the vast majority of axotomized labeled cells appeared to have died. Quantitative evaluation of labeled cells showed that the region of cortex within 1 mm of the axotomizing injury had less than 10% of the expected neuronal density in animals surviving at least 4 weeks after injury. Close axotomy appears to cause dramatic loss of transcallosal neurons even in adult animals.

Proliferating cell nuclear antigen (PCNA) immunolocalization in human nasal epithelium with chronic sinusitis detected by confocal laser scanning microscopy

This study examines the immunohistological localization of proliferating cell nuclear antigen in the nasal and paranasal sinus epithelium from a group of patients undergoing sinus surgery for chronic sinusitis. PCNA immunoreactivity as determined by fluorescence intensity and the density of labeled cells as assessed by confocal laser scanning microscopy. The control group consisted of seven specimens taken from patients with post operative maxillary cyst and optic nerve canal fracture. In this group, most of the labeled cells were located on the basal cell layers with a few on the intermediate cell layers. The average labeled cell densities were 57.3 cells/mm2 on the basal cell layers and 15.9 cells/mm2 on the intermediate cell layer. The sinusitis group consisted of eleven patients. In contrast with the control group, the sinusitis epithelium displayed a significantly high proportion of goblet and intermediate cells positively stained for PCNA. The average densities were 84.9 cells/mm2 on the basal cell layers and 133.1 cells/mm2 on the intermediate cell layers in this group, the latter being nearly ten fold greater than that in the control group. Epithelial PCNA expression was correlated with the degree of inflammatory cell infiltration assessed by serial sections for each sample. A positive correlation was observed between these two factors (R = 0.63, Pearson). We believe that epithelial cell turnover is accelerated in chronic rhinosinusitis due to continuous exposure to various pathogens and host immune interventions. In those cases, goblet and intermediate cells would play the major role in enhanced epithelial proliferation.

Direct evidence for loss and replacement of projection neurons in adult canary brain

Normally occurring projection neuron loss and replacement were quantified over a 6 month period in the pathway from the high vocal center (HVC) to the robust nucleus of the archistriatum (RA) in adult male canaries. Fluorescent latex microspheres were injected into RA in April--a procedure resulting in long-term retrograde labeling of RA-projecting HVC neurons. Labeled cell densities were then obtained 4 and 20 d later in April and 195 d later in October. We found that 41-49% of the RA-projecting HVC neurons present the previous April were no longer present in October. Fluorogold injections in RA 3 d prior to death in April and October retrogradely labeled similar overall densities of RA-projecting HVC neurons, indicating that cells lost over this 6 month period were replaced by new RA-projecting HVC neurons. Newer cells were larger than older cells, suggesting that an age-dependent reduction in size might precede death. Over the same time interval, no loss was observed for neurons projecting from the lateral magnocellular nucleus of the anterior neostriatum to RA. Thus, loss was specific to the input from HVC to RA. These findings raise the possibility that much if not all of the pathway from HVC to RA is replaced within a year. The time period examined encompasses the yearly transition from stable song to song learning in the canary (Nottebohm et al., 1986, 1987). A pronounced loss and replacement of neurons implicated in vocal control during this period may relate to the canary's ability to modify song in adulthood.

Cell proliferation in carcinoma in bilharzial bladder: Influence of pre-operative irradiation and clinical implications

Cell proliferation in carcinoma in the bilharzial bladder was studied in 92 patients in terms of the in vitro labeling index (LI), cell density (CD) and labeled cell density (LCD) using the in vitro 3H-Tdr technique. Cell proliferation was much greater in high than in low grade tumors and in deep than in superficial parts of the tumor, but was much less dependent on cell type; transitional cell cancer had the highest activity followed by squamous cell and adenocarcinoma. The probability of local recurrence after cystectomy decreased markedly when the LI exceeded 5.0%. The influence of the following three pre-operative radiotherapy regimens was studied: a.) split-course (SC): the initial course consisted of 20 Gy in 10 treatments with a similar course was given after one week, b.) hyper-fractionation using 17 treatments 0.6 Gy each on two successive days, this 2-day course of 20 Gy was repeated after one week, and c.) concentrated irradiation consisting of two treatments, 6.0 Gy each with a gap of one week. Cystectomy was performed 14–20 days after treatment in all groups. Preoperative irradiation was generally associated with an increased probability of local control. The unfavorable influence of a high pretreatment LI was not noted after pre-operative irradiation. The CD was also reduced in proportion to the pretreatment LL It is proposed that the response to irradiation was proportional to the initial proliferation activity and hence the prognostic significance of tumor grade and pretreatment LI was masked. Postirradiation tumor volume reduction was a strong predictor of treatment outcome. Concentrated irradiation was the least efficient pre-operative irradiation regimen and was associated with the least tumor volume reduction.