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Biomedical subjects

H Stein

Publications and source records attributed to H Stein.

At least 127 records · Page 7Linked to original sources

Frequent expansion of Epstein-Barr virus (EBV) infected cells in germinal centres of tonsils from an area with a high incidence of EBV-associated lymphoma.

Burkitt's lymphoma (BL) and Hodgkin's disease (HD) occurring in developing regions are frequently associated with Epstein-Barr virus (EBV) infection and have a high incidence in childhood. Recent genotyping studies indicate that the tumour cells of both neoplasms represent B cells that contain somatically mutated immunoglobulin heavy chain genes. This implies that the precursors of these neoplasms have participated in the germinal centre (GC) reaction. We therefore presumed that normal lymphoid tissues from children living in developing regions would harbour an increased number of EBV-infected cells within the GC, when compared with children living in industrialized nations. To test this hypothesis, hyperplastic tonsils from 40 children living in Bahia (Brazil) and 40 from German children were analysed for the presence of EBV-encoded small nuclear RNA (EBER) and EBV-encoded proteins by in situ hybridization and immunohistology, respectively. Although the overall EBV infection rate was similar in both groups (50 per cent of Bahian vs. 45 per cent of German cases), a significantly higher number of EBER-positive lymphoid cells were found in the GCs of 8/20 EBV-positive tonsils from Brazil (9-89 cells/GC; mean: 14.5 cells/GC per case), while only 3/18 tonsils from Germany displayed a few EBER positive cells (1-9 cells/GC; mean: 0.5 cell/GC per case) in this compartment (p < 0.007). In addition, the EBV-infected GC cells in Bahian samples resembled centroblasts, exhibited mitotic activity, and in two cases showed expression of EBV-encoded latent membrane protein (LMP)-1, findings not present in German samples. These data show that latently EBV-infected cells participate more frequently in GC reactions in developing regions than in industrialized countries and may abnormally express the oncogenic protein LMP-1. This could in part explain the higher incidence in this region of EBV association with lymphomas related to GC cells or their progeny, such as BL and HD.

Adolescent↗

Common and HIV-related diffuse large B-cell lymphomas differ in their immunoglobulin gene mutation pattern.

HIV-infected patients are at high risk of developing diffuse large B-cell lymphomas (DLBCL). It is currently unclear whether these lymphomas represent Epstein-Barr virus (EBV)-driven lymphoproliferations that develop in the setting of immunodeficiency, or whether these tumours are more closely related to the DLBCL seen in the general population. To clarify this issue, 12 HIV-related DLBCL from 11 patients were analysed for the presence of clonally rearranged and somatically mutated immunoglobulin heavy chain (IgH) genes and their association with EBV was determined. Eleven of the 12 tumour samples displayed monoclonal rearrangements of the IgH genes, with or without a moderate number of somatic mutations in the CDRII and in the FWIII regions (average four mutations). One patient presented two successive lesions; whereas the initial tumour showed an oligoclonal IgH rearrangement, the lymphoma at relapse proved to harbour a monoclonal B-cell population. Ten of 12 tumour samples expressed the EBV encoded small RNAs (EBERs), and six of these EBV-positive cases displayed, in addition, an expression of the EBV encoded nuclear antigen 2 (EBNA-2). The results obtained from HIV-related DLBCL are at variance to those described for DLBCL occurring in the general population, since the latter contain significantly more somatic IgH mutations in the CDRII and in the FWIII regions and are only rarely associated with EBV. It is concluded from these findings that HIV-related DLBCL represent a distinct group of B-cell lymphomas, a significant fraction of which most likely originates from EBV-driven lymphoproliferations, and that half of the cases derive from pre-germinal centre B-cells.

Gene Rearrangement↗

Hodgkin and Reed-Sternberg cells of classical Hodgkin's disease overexpress the telomerase RNA template (hTR).

There is accumulating evidence to suggest that Hodgkin and Reed-Sternberg (HRS) cells represent the malignant cell population in Hodgkin's disease (HD). A recent report that HD tissue is in most instances devoid of telomerase activity was therefore unexpected. Since telomerase activity was determined in whole tissue extracts and HRS cells comprise only a small minority of the cells in the affected tissue, the telomerase activity of the HRS cells might have escaped detection. To test this possibility and to clarify whether HRS cells contain the enzyme telomerase, 13 cases of classical HD were analysed by three different methods. The presence of telomerase was studied at the single cell level by a sensitive radioactive in situ hybridization method employing a probe specific for the telomerase RNA template (hTR). In addition, tissue extracts were studied for telomerase activity by a modified TRAP assay and for hTR by reverse transcription-polymerase chain reaction (RT-PCR). The extractive methods revealed telomerase activity in eight and hTR in all of the 13 HD cases studied. In situ hybridization located large amounts of hTR in the HRS cells of all 13 HD cases and low to medium amounts in some of the non-malignant lymphoid bystander cells. These results indicate that HRS cells constitutively overexpress telomerase and thus use this enzyme for stabilizing their telomeres. This substantiates the malignant nature of HRS cells. Furthermore, the results confirm that normal lymphoid cells can express telomerase. In consequence, methods of measuring telomerase in tissue extracts are not suitable for determining the presence of this molecule in lymphoma cells, since the vast majority of lymphoid neoplasms contain significant amounts of non-neoplastic lymphoid cells.

Hodgkin Disease↗

Clonal T-cell receptor gamma-chain gene rearrangement by PCR-based GeneScan analysis in advanced cutaneous T-cell lymphoma: a critical evaluation.

Detection of clonal T-cell receptor gamma (TCRgamma)-chain gene rearrangement is a promising approach to distinguish between cutaneous T-cell lymphomas (CTCLs) and reactive T-cell infiltrates. Despite the improved sensitivity by using the polymerase chain reaction (PCR) rather than Southern blot analysis, monoclonality could be demonstrated in only 53-90 per cent of CTCL biopsies in recent studies. In the present study, formalin-fixed, paraffin-embedded specimens of 21 selected patients with clear-cut advanced-stage CTCL were analysed using a semi-nested TCRgamma PCR with newly developed consensus primer pairs. Detection of PCR products was done by GeneScan analysis (GSA); this technique is advantageous due to its sensitivity and accuracy in the detection and size determination of PCR products and it is easier to interpret than direct read-outs from TGGE or DGGE gels. In serial dilution experiments, TCRgamma-PCR-GSA allowed the detection of clonal, rearranged T-cells with a high in vitro sensitivity against a polyclonal background (1-6 per cent). Despite the selection of clear-cut, advanced-stage CTCL cases, however, dominant clonal TCRgamma-chain gene rearrangement was found in only 16 of the 21 patients analysed, indicating an overall clinical sensitivity of 76 per cent. Specificity was evaluated using biopsy specimens from 21 control patients suffering from long-standing psoriasis (n=13) and eczema (n=8). Surprisingly, GeneScan profiles showing apparently single dominant peaks were detected in 14 per cent of these skin lesions, but these profiles turned out to be pseudo-monoclonal by repeated determinations. In conclusion, TCRgamma-PCR-GSA does not suffice reliably to exclude malignancy, due to its limited clinical sensitivity, but with precautions taken to detect pseudo-monoclonality and to secure specificity, TCRgamma-PCR-GSA is a valuable instrument in the diagnosis of CTCL.

Diagnosis, Differential↗

T-cell and T/natural killer-cell lymphomas involving ocular and ocular adnexal tissues: a clinicopathologic, immunohistochemical, and molecular study of seven cases.

OBJECTIVE: Lymphomas of the eye and its adnexa are frequently of B lineage. This study aims to characterize the clinical and histopathologic features of the rare non-B-cell non-Hodgkin lymphomas (NHL) of these locations. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Seven cases of T- and T/NK-cell lymphomas involving the ocular and ocular adnexal tissues. METHODS: A morphologic, immunohistochemical, and molecular analysis (polymerase chain reaction) of each of the tumors was undertaken. The lesions were classified according to the Revised European-American Lymphoma (REAL) classification. The clinical and follow-up data were collected. RESULTS: The patients included four women and three men ranging in age from 32 to 88 years (mean, 63 years). The presenting ophthalmic symptoms varied from a small nodule on the upper eyelid and conjunctival swellings to dramatic loss of vision associated with gross protrusion of the globe. Five of the cases presented were secondary manifestations of a systemic lymphoma in ocular tissues; two cases represented primary disease. Three cases were "peripheral T-cell lymphomas (PTCL), unspecified" with positivity for CD3, CD8, and betaF1 and negativity for CD56. Two cases were CD3+, CD30+, and CD56- and were classified as "anaplastic large-cell lymphomas of T-cell type" (T-ALCL). The remaining two cases showed an immunophenotype of CD3+, CD56+, and betaF1- and proved to contain Epstein-Barr virus (EBV) by in situ hybridization, consistent with "T/natural killer (NK)-cell lymphoma of nasal type." Clonal T-cell populations were shown in all three of the PTCLs by Southern blot (n = 1) and polymerase chain reaction (n = 2) for the T-cell receptor gamma and beta genes in one case of ALCL but not in the T/NK-cell lymphomas. Five patients died within 2 years; only two patients (one primary PTCL and one cutaneous T-ALCL) were disease free at 4 and 5 years' follow-up, respectively. CONCLUSION: This study shows that a heterogeneous group of T-cell lymphomas can involve the eye and its adnexal tissue. Most T-cell neoplasms are secondary manifestations of systemic disease and carry a poor prognosis. These findings, in conjunction with published data on ocular B-NHL, also indicate that immunophenotypic differentiation between T- and B-NHL in these locations is of clinical importance.

Adult↗

Tannic acid and thiocarbohydrazide as structural reinforcement agents in the preparation of rabbit knee articular cartilage for the scanning electron microscope.

Samples from seven sectors of the rabbit knee articular cartilage were shaved and prepared for the scanning electron microscope using either tannic acid, thiocarbohydrazide or nothing (control). Surface morphology was found to be more typical to a given sector and less so to a specific preparation procedure. Rough areas were recorded from load-bearing sectors, while smooth areas appeared on load-free ones. However, fibrillations were discerned on control load-bearing sectors only, and pits and humps were never detected. Tannic acid and thiocarbohydrazide may have exerted their structural reinforcing effect on the tissue preservation by enhancing the binding of osmium tetroxide to it, possibly along with that of other soluble tissue constituents.

Animals↗

FasL is more frequently expressed in liver metastases of colorectal cancer than in matched primary carcinomas.

Colorectal carcinoma cells have recently been shown to express Fas ligand (FasL). This ligand could allow the tumour cells to evade activated tumour-infiltrating lymphocytes (TILs) by inducing their apoptosis and would thus promote tumour survival and possibly metastasis formation. To test this hypothesis in vivo we analysed the expression of FasL mRNA and protein in paired tissue samples of normal colonic mucosa (N), primary colorectal carcinomas (T) and their metastases (M) from a total of 21 patients by four different methods. Additionally, the presence and activation status of infiltrating lymphocytes, which might contribute to the total amount of FasL in the tissue, was determined by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) in the same samples. The frequency of FasL detection was 30-40% in T and was 60-100% in M, depending on the sensitivity of the method. Simultaneously, the amount of CD25 mRNA, used as a measure of the number of activated TILs, was in 90% of patients lower in M than in T. The increased frequency of FasL detection in liver metastases was therefore not due to the presence of activated TILs. We conclude that metastasizing subpopulations of colorectal tumour cells express FasL more frequently than the primary carcinomas and may be able to eliminate activated TILs in vivo via Fas/FasL-induced apoptosis or other hitherto unknown mechanisms.

Colorectal Neoplasms↗

Follicular mycosis fungoides.

We describe a patient with follicular mycosis fungoides (MF), a rare folliculotropic variant of cutaneous T-cell lymphoma (CTCL). Follicular involvement in CTCL usually presents clinically as alopecia mucinosa associated histologically with follicular mucinosis. Follicular MF differs from alopecia mucinosa/follicular mucinosis associated with MF with regard to its clinical presentation, histology and, presumably, prognosis. Our patient presented with the characteristic findings of follicular MF, i.e. infiltrated plaques showing numerous enlarged, comedo-like follicular infundibula; histology was dominated by exclusive folliculotropism of atypical lymphocytes sometimes forming follicular Pautrier's microabscesses, and by lack of epidermotropism and follicular mucinosis. Despite photochemotherapy and treatment with oral retinoids and interferon alpha, the patient's follicular MF rapidly developed into a progressive CTCL with large tumorous lesions, but responded to electron beam therapy. The course of our patient's disease confirms the notion that follicular MF may be associated with a worse prognosis than classical MF. However, electron beam irradiation induced remission of follicular MF that was maintained by a combination therapy consisting of extracorporeal photopheresis and interferon alfa.

Aged↗

Soluble cytokine receptor CD30 in atopic disorders: a case-control study.

BACKGROUND: The cytokine receptor CD30 is an activation marker of T cells which preferentially associates with the production of the TH2 cytokine IL-4. Therefore, it may potentially be a candidate marker for atopic disorders and a target molecule for new therapeutic approaches. OBJECTIVE: To test the hypothesis that elevated levels of soluble CD30 (sCD30) are significantly associated with atopic disorders after adjustment for other predictors of atopy. METHODS: The presence of elevated sCD30 (> or = 20 U/mL) in atopic disorders was evaluated in a nested case-control study. Cases (n = 60) were blood donors with specific IgE antibodies, total serum levels of IgE > or = 100kU/L and presence or history of allergic symptoms. Controls (n = 59) were blood donors without presence or history of allergic symptoms and serum levels of IgE < 50 kU/L. sCD30 was determined from serum samples by an enzyme-linked immunosorbent assay. Odds ratios (OR) and confidence intervals (CI) were calculated from logistic regression coefficients. RESULTS: Mean sCD30 levels for cases were 75 U/mL (SD 110U/mL) as compared with 35 U/mL (SD 59 U/mL) for controls. Serum levels of sCD30 were elevated in 65% of cases and 32% of controls (OR 3.9, 95% CI 1.8-8.4). The odds ratio for elevated sCD30 as a predictor of atopic disorders slightly decreased to 3.7 after controlling for smoking, age and gender. Blood eosinophilia which was a strong predictor of atopy (OR 11.7) was a weak confounder of the association between sCD30 levels and atopic disorders. Family history of allergy, another strong predictor of atopy (OR 8.6), did not confound the association. CONCLUSIONS: The results are consistent with the hypothesis that CD30 is involved in the pathogenesis of atopic disorders independent of eosinophilia and family history of allergy.

Adolescent↗

Origin of primary gastric T-cell lymphomas from intraepithelial T-lymphocytes: report of two cases.

AIMS: The classification of primary gastric T-cell lymphomas is uncertain due to the exceeding rarity of these tumours; many of the reported cases were felt to be similar to node-based lymphomas. We describe two cases of primary gastric T-cell lymphoma with evidence of origination from intraepithelial T-lymphocytes. METHODS AND RESULTS: Both tumours were restricted to the stomach; one displaying a large ulcerated mass, the other a widespread superficial tumour manifestation. Histologically the first tumour was composed of sheets of medium-sized lymphoid cells showing marked epitheliotropism at the edge of the ulcer, and a CD3+, CD4-, CD8-, CD20-, CD56-, CD103+, beta F1+ phenotype. The second case differed histologically and immunophenotypically from the first case. In addition to lamina propria and submucosal infiltration, the lymphoma contained an extensive intraepithelial component even in large areas without other evidence of tumour. The neoplastic cells ranged in size from small to medium and large. Immunohistology disclosed a CD3+, CD4+, CD8-, CD20-, CD56-, beta F1+ phenotype. Staining for CD103 could not be performed in this case since frozen material was not available. CONCLUSIONS: The prominent epitheliotropism, the marked intraepithelial growth and the expression of CD103 strongly imply a derivation of these primary gastric lymphomas from intraepithelial T-lymphocytes. Additional studies of larger series will clarify whether the findings described here are typical of primary gastric T-cell lymphomas.

Adult↗

Tenascin labelling in colorectal biopsies: a useful marker in the diagnosis of collagenous colitis.

AIMS: This study was undertaken to clarify whether immunohistological detection of tenascin (TN), an extracellular matrix glycoprotein that is expressed during stromal remodelling, may allow a more precise diagnosis of collagenous colitis. METHODS AND RESULTS: We studied multiple colorectal biopsies specimens from 15 patients with clinically suspected collagenous colitis for TN expression by using a monoclonal antibody. Biopsies from further 15 patients without symptoms and signs of collagenous colitis served as controls. In seven of the 15 cases with clinically suspected collagenous colitis a prominent and selective subepithelial tenascin expression was identified. The TN expression pattern closely correlated with the conventional detection of a subepithelial collagen band diagnostic of collagenous colitis. The immunohistological labelling for TN allowed a quicker and more precise measurement of the thickness of the diagnostic collagen deposits than conventional staining. By this approach one further case could be reclassified as collagenous colitis. CONCLUSIONS: Our data show that immunohistological detection of TN allows a more correct and easy diagnosis of collagenous colitis.

Adult↗

Increased expression of mRNA for matrix metalloproteinases-1 and -3 and tissue inhibitor of metalloproteinases-1 in intestinal biopsy specimens from patients with coeliac disease.

BACKGROUND: Extracellular matrix (ECM) degradation may play a role in villus atrophy in coeliac disease (CD). AIMS: To compare the cellular expression of mRNA transcripts for the two major matrix degrading proteases, matrix metalloproteinase (MMP)-1 and MMP-3, their inhibitor, tissue inhibitor of metalloproteinases (TIMP)-1, and procollagen I in the intestinal mucosa of patients with untreated and treated CD and normal controls. PATIENTS/METHODS: Duodenal biopsy specimens from ten untreated CD patients, from six of these after a gluten free diet, and from ten control patients were hybridised with 35S-labelled RNA probes. The number of positive cells in the subepithelial region and lamina propria were counted microscopically. RESULTS: The numbers of cells positive for MMP-1 (p<0.005), MMP-3 (p<0.01), and TIMP-1 (p<0.05) mRNA were higher in the subepithelial region of CD mucosa than in that from controls. In the lamina propria, only cells positive for MMP-1 mRNA were increased in CD patients compared with controls (p<0.01). MMP-1 and MMP-3 mRNA expression returned to normal in CD patients after treatment with a gluten free diet (p<0.05), while TIMP-1 mRNA expression remained elevated. The number of procollagen I mRNA expressing cells did not change. Expression of MMP-1 and MMP-3 mRNA was mainly localised to subepithelial fibroblasts and macrophages. CONCLUSIONS: The decreased ratio of collagen I and TIMP-1 mRNA expressing cells to MMP-1 and MMP-3 mRNA expressing cells in untreated CD suggests a shift towards ECM degradation. ECM degradation by activated subepithelial fibroblasts and macrophages may be an important mechanism driving mucosal transformation in CD.

Adult↗

AIDS-related plasmablastic lymphomas of the oral cavity and jaws: a diagnostic dilemma.

Acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin's lymphomas are highly pleomorphic in their clinical, pathological, and biological features. Recent investigations have led to the identification of a particular type of AIDS-related non-Hodgkin's lymphomas presenting in the oral cavity and jaws. This novel category of AIDS-related non-Hodgkin's lymphomas derives from B-cells and has been defined as plasmablastic lymphoma on the basis of its morphological and immunophenotypic features. Clinically, AIDS-related plasmablastic lymphoma is generally limited to the oral cavity at the time of diagnosis, although extension to distant sites frequently occurs at a later stage. Histologically, AIDS-related plasmablastic lymphoma is composed of a monomorphic and cohesive pattern of plasmablasts with basophilic cytoplasm. Phenotypically, AIDS-related plasmablastic lymphoma fails to express the most common B-cell-associated surface antigens, whereas it consistently expresses high levels of plasma cell-associated markers, including VS38c and CD138/syndecan-1. For the purpose of differential diagnosis, the morphological and immunophenotypic peculiarities of AIDS-related plasmablastic lymphoma clearly distinguish these lymphomas from other categories of AIDS-related non-Hodgkin's lymphomas, as well as from undifferentiated large cell carcinomas.

Antibodies, Neoplasm↗

Classical Hodgkin's disease and follicular lymphoma originating from the same germinal center B cell.

PURPOSE: Classical Hodgkin's disease and non-Hodgkin's B-cell lymphoma occasionally occur in the same patient. To clarify whether these different diseases share a common precursor cell, we analyzed the immunoglobulin rearrangements in tumor cells of the classical Hodgkin's disease and the follicular lymphoma that developed in the same patient 2 years apart. PATIENTS AND METHODS: Polymerase chain reaction (PCR) for the detection of rearranged immunoglobulin genes was carried out on single Reed-Sternberg cells and on whole tissue DNA extracted from the follicular lymphoma. PCR products were sequenced and compared with each other and with germ line immunoglobulin variable segments. Immunoglobulin heavy- and light-chain transcripts were analyzed by radioactive in-situ hybridization. RESULTS: The same monoclonal immunoglobulin gene rearrangement was found in both neoplasms. The variable region of the immunoglobulin heavy-chain genes of the Reed-Sternberg and of the follicular lymphoma cells were differently mutated, but six somatic mutations were shared by both lymphoma cells. Although the coding capacity of the immunoglobulin genes was preserved in both neoplastic cell populations, immunoglobulin heavy- (mu) and light- (kappa) chain expression was restricted to the follicular lymphoma cells, except for small amounts of kappa light-chain mRNA in some Reed-Sternberg cells. CONCLUSIONS: The neoplastic cells of the Hodgkin's disease and the follicular lymphoma that occurred in this patient derived from a common precursor B cell. Its differentiation stage could be identified as that of a germinal center B cell. Thus, transforming events can be more important than the cell of origin in determining a disease entity.

Adult↗

Clinical presentation, course, and prognostic factors in lymphocyte-predominant Hodgkin's disease and lymphocyte-rich classical Hodgkin's disease: report from the European Task Force on Lymphoma Project on Lymphocyte-Predominant Hodgkin's Disease.

PURPOSE: Recent studies have suggested that lymphocyte-predominant Hodgkin's disease (LPHD) is both clinically and pathologically distinct from other forms of Hodgkin's disease, including classical Hodgkin's disease (CHD). However, large-scale clinical studies were lacking. This multicenter, retrospective study investigated the clinical characteristics and course of LPHD patients and lymphocyte-rich classical Hodgkin's disease (LRCHD) patients classified according to morphologic and immunophenotypic criteria. MATERIALS AND METHODS: Clinical data and biopsy material of all available cases initially submitted as LPHD were collected from 17 European and American centers, stained, and reclassified by expert pathologists. RESULTS: The 426 assessable cases were reclassified as LPHD (51%), LRCHD (27%), CHD (5%), non-Hodgkin's lymphoma (3%), and reactive lesion (3%); 11% of cases were not assessable. Patients with LPHD and LRCHD were predominantly male, with early-stage disease and few risk factors. Patients with LRCHD were significantly older. Survival and failure-free survival rates with adequate therapy were similar for patients with LPHD and LRCHD, and were stage-dependent and not significantly better than stage-comparable results for CHD (German trial data). Twenty-seven percent of relapsing LPHD patients had multiple relapses, which is significantly more than the 5% of relapsing LRCHD patients who had multiple relapses. Lymphocyte-predominant Hodgkin's disease patients had significantly superior survival after relapse compared with LRCHD or CHD patients; however, this was partly due to the younger average age of LPHD patients. CONCLUSION: The two subgroups of LPHD and LRCHD bore a close clinical resemblance that was distinct from CHD; the course was similar to that of comparable nodular sclerosis and mixed cellularity patients. Thorough staging is necessary to detect advanced disease in LPHD and LRCHD patients. The question of how to treat such patients, either by reducing treatment intensity or following a "watch and wait" approach, remains unanswered.

Adult↗

Muscle recovery after immobilisation by external fixation.

We immobilised the right hindlimbs of six-month-old female Wistar rats for four weeks using a biplanar external fixation bridging the knee. The untreated left limbs served as a control group. An additional group of rats was allowed to recover for four weeks after removal of the frame. Immobilisation caused reduction in the wet weights of approximately 50% in the gastrocnemius, quadriceps, soleus and plantaris muscles; this was not restored completely after remobilisation. There was an increase in the activity of acid phosphatase of approximately 85% in the gastrocnemius and quadriceps muscles whereas that of creatine phosphokinase was reduced by about 40%. These values returned to nearly normal after remobilisation. Histological and ultrastructural examination showed a marked myopathy of the gastrocnemius muscle after immobilisation although the morphology was largely restored after remobilisation. We conclude that after four weeks of remobilisation, hind-limb muscles do not return to preimmobilisation weights, although biochemical activities and ultrastructural appearance are largely restored.

Acid Phosphatase↗