BackgroundThe immune escape or tolerance of cancer cells is considered to be closely involved in cancer progression. Programmed death-1 (PD-1) is an inhibitory receptor expressed on activating T cells, and several types of cancer cells were found to express PD-1 ligand 1 (PD-L1) and ligand 2 (PD-L2).MethodsIn the present study, we investigated PD-L1/2 expression in papillary renal cell carcinoma (pRCC).ResultWe found PD-L1 expression in 29 of 102 cases, but no PD-L2 expression was seen. PD-L1 expression was not significantly correlated with any clinicopathological factor, including progression-free survival and overall survival. The frequency of PD-L1-positive cases was higher in type 2 (36%) than in type 1 (22%) pRCC; however, there was no significant difference in the percentages of score 0 cases (p value = 0.084 in Chi-square test). The frequency of high PD-L1 expression cases was higher in type 2 (23%) than in type 1 (11%), and the frequency of high PD-L1 expression cases was higher in grade 3/4 (21%) than in grade 1/2 (13%). However, no significant association was found between PD-L1 expression and all clinicopathological factors in pRCC.ConclusionHigh expression of PD-L1 in cancer cells was potentially associated to highly histological grade of malignancy in pRCC. The evaluation of the PD-L1 protein might still be useful for predicting the efficacy of anti-cancer immunotherapy using immuno-checkpoint inhibitors, however, not be useful for predicting the clinical prognosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12894-016-0195-x) contains supplementary material, which is available to authorized users.

SUMMARY:Human cerebellum is important for motor coordination; muscle tones and maintaing the equilibrium of the body. In our region, limited data is available on the normal morphology of human cerebellum, whilst fresh biopsy is quite difficult to obtain. Here adult male cerebellum from cadaver anatomy preparations embalmed with 37 % formalin fixative solution for over a year are studied (n=3). After removal, right cerebellum hemisphere was sliced into cubicle then temporary soaked into 50-60 % of alcohol before being paraffinated. Two parasagittal adjacent slices from each sample were deparaffinated (5 µm) and then stained with hematoxyllin-eosin (HE). Slides were observed under light microscope (Olympus, Japan). Pictures were analysed from 6 field numbers of each, with Optilab and Image Raster 3 software (Indonesia). The density of the Purkinje cells (Neuron purkinjense), the number and density of the Purkinje cells and the thickness of the molecular layer are measured. Data were analysed with the level of significance of p<0.05 (ANOVA, Microsoft Excel 2007). The distance between 2 Purkinje cells is ranged between 82.6-346.6 µm, although no significant differences found (p=0.1). There are no significant differences in the number and in the density of the Purkinje cells amongst samples (p=0.72 and 0.34, respectively); might be due to the similar age, sex and race of these cadavers. However, there is a significant difference in the thickness of the molecular layer (p=0.015). Variations amongst individual cerebelli are observed, with a significant different thickness in the molecular layer. The cellular composition of each cerebellum is unique, arguably correlated to the individual cerebellum activity when alive.

Fixation is one of the processes in preparing histology and pathology. The common material for fixation is buffered formalin including paraformaldehyde. However, the effect of the damaged cells, which is fixed for a long time, causes the research for other fixation materials to become necessary. In addition, paraformaldehyde is also harmful to human body and natural environment. Ethanol is one of the alternative fixation materials, which has been used for two hundred years. It has been used for many purposes, both in routine staining and immunohistochemistry. Nonetheless, no research confirms its effect on the electron microscope. The authors studied the effect of 50 % of ethanol on the cell membrane, organelles, and nucleus of Purkinje cells (Neuron purkinjense) observed on a light microscope and Transmitted Electron Microscope (TEM). Then it was compared to buffered formalin. In the light microscope, it shows that both of fixations have no different effects of the morphology of the cell membrane, cytoplasm, the nucleus of Purkinje cells and the neutrophils. We assume that our 50 % of ethanol concentration is almost the same as BF 10 % in the ability of hardening tissue and color absorption based on the previous study. In TEM, the structure of the cell membrane, organelles, and cytoplasm of Purkinje cell look broken in the cerebellum of 50 % of ethanol except for the nucleus. There was no significant difference diameter of the nucleus. It happened in general because of the shrinkage effect of ethanol. However, the authors recommend using 50 % of ethanol for routine staining.

Histopathology is the science that studies disease pathology through morphological changes that can be seen microscopically. The word histopathology was first known to be introduced in a book entitled “On the Nature and Structure Characteristic of Cancer” by Johannes Muller in 1838. Before histopathology, doctors distinguished diseases based on macroscopically visible morphology organ changes (anatomy) in the operating room or during forensic autopsies. However, this expertise requires another diagnosis method to ensure that several differential diagnoses indicate the same anatomical morphological changes. Definitive diagnosis is obtained by taking a small organ tissue sample during surgery (biopsy), which is then viewed microscopically. This diagnosis method is called histopathological diagnosis. For example, a person with hearing loss has received a differential diagnosis of conduction or sensorineural hearing loss. An external macroscopic physical examination for this patient is as necessary as internal imaging. The condition’s pathological cause can be ascertained by additional histopathology biopsies. However, invasive histopathology procedures can be uncomfortable and cause harm. Histopathology for diagnostic or research purposes requires two fundamental things: the microscope as a tool and the development of histopathological techniques.