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Biomedical subjects

József Kónya

Publications and source records attributed to József Kónya.

At least 19 recordsLinked to original sources

Study of pH-dependent charges of soils by surface acid-base properties.

The pH-dependent charges of Hungarian soils have been studied via surface acid-base properties. The intrinsic stability constants of protonation and deprotonation processes, as well as the concentration of surface sites, have been determined by surface complexation modeling. The protonation and deprotonation constants have been nearly the same for most soils. There is a relation between the concentration of surface sites and composition, expect for the freshly deposited soils with high primary silicate content. The results show that the concentrations of silanol and aluminol sites are different for each soil, the intrinsic stability constants of protonation and deprotonation processes, however, are nearly the same within experimental error. This can only be explained if these stability constants are real thermodynamic equilibrium constants. The fact that these constants are nearly the same supports the conclusion that we succeeded in excluding all processes that would disturb the measurements. The parameters characteristic of the edge sites of the soils are of two types: (a) the parameters depending on the quality and composition of the soils, (i.e.), the concentration of surface sites; (b) the parameters depending on the thermodynamically well-defined acid-base processes, independent of soil composition.

Journal Article↗

Human herpesvirus 6A decreases the susceptibility of macrophages to R5 variants of human immunodeficiency virus 1: possible role of RANTES and IL-8.

Human herpesvirus 6 (HHV-6) frequently reactivates in human immunodeficiency virus 1 (HIV-1) infected patients, and is thought to be a cofactor in AIDS progression. Macrophages are targets and reservoirs of HIV-1 and HHV-6; hence, they have an important role in dissemination and pathogenesis of these viruses. The present study examined the effects of HHV-6 A variant on replication of R5 variants of HIV-1 in macrophages. For this purpose, HIV-1 replication was investigated in macrophages infected with HIV-1 alone or along with HHV-6A. Our results demonstrated that HHV-6A significantly suppressed HIV-1 replication in coinfected cultures. HHV-6A infection resulted in increased secretion of RANTES and IL-8. Experiments with exogenous RANTES and IL-8 revealed that these chemokines also significantly suppressed HIV-1 replication in infected macrophages. RANTES is able to induce desensitization and internalization of CCR5, the chemokine coreceptor of R5 variants. In addition, IL-8 receptor activation results in cross-desensitization and cross-internalization of CCR5. We found that CCR5 sensitivity and expression level is diminished in HHV-6A-infected macrophage cultures compared with uninfected cells. Taken together, our results indicate that HHV-6A infection decreases the susceptibility of macrophages to R5 variants of HIV-1 in which the HHV-6A induced RANTES and IL-8 may have importance.

Cells, Cultured↗

Antimeasles immunoglobulin g for serologic diagnosis of otosclerotic hearing loss.

HYPOTHESIS: Persistent measles virus infection of the otic capsule is suggested to be an etiologic factor in otosclerosis. Otosclerosis is a disease of complex unknown etiology causing progressive conductive and/or sensorineural hearing loss (HL). BACKGROUND: Diagnostic methods of otosclerosis are sensitive to ossicular chain fixation with low specificity for otosclerotic stapes ankylosis. METHODS: Nucleic acid was extracted from stapes foot plates of clinically stapes fixation patients (N = 213). Measles virus nucleoprotein RNA was amplified by reverse-transcriptase polymerase chain reaction. Amplification results were correlated to histologic findings in 49 cases. Antimeasles IgG levels of all clinically stapes fixation as well as control sera specimens were measured by enzyme-linked immunosorbent assay. RESULTS: Among clinically stapes fixation patients, 141 stapes foot plates contained measles virus RNA. Among 49 histologic specimens, viral RNA was detectable only in histologically otosclerotic stapes foot plates (n = 35). Histology for virus-negative foot plates (n = 14) excluded otosclerosis. Antimeasles IgG levels were significantly lower in the sera of patients with virus-positive stapes than in control sera. CONCLUSIONS: Combination of decreased antimeasles IgG serum level and conductive HL has a great specificity and sensitivity as a diagnostic method in the preoperative evaluation of ossicular chain fixations otosclerosis. Low antimeasles IgG level indicates otosclerosis, whereas high level suggests non-otosclerotic ossicular chain fixations. Preoperative elucidation of the cause of a conductive HL may suggest optional medical treatment in preference to surgical methods.

Adult↗

Detection of osteoprotegerin and TNF-alpha mRNA in ankylotic Stapes footplates in connection with measles virus positivity.

HYPOTHESIS: Otosclerosis is a bone remodeling disorder of the otic capsule causing conductive and sensorineural hearing loss. Persistent measles virus infection of the temporal bone with increased tumor necrosis factor (TNF)-alpha and decreased osteoprotegerin mRNA expression is supposed to be the main etiologic factor in otosclerosis. BACKGROUND: Determinants of measles virus infection and reactive inflammation were studied in otosclerosis. The presence of measles virus was shown in otosclerotic patients by reverse transcriptase-polymerase chain reaction (RT-PCR) amplification of the viral RNA. No report is available, however, about the role and interactions of bone-specific cytokines in otosclerosis. METHODS: : Nucleic acid was extracted from stapes footplates of clinically otosclerotic patients. Measles virus nucleoprotein RNA was amplified by seminested RT-PCR. TNF-alpha and osteoprotegerin mRNA coexpression was detected by RT-PCR in otosclerotic bone and was correlated to measles virus positivity. RESULTS: Among 154 clinically stapes fixation otosclerotic patients, 99 stapedes contained measles virus RNA. TNF-alpha mRNA was detectable in 88 virus-positive and in 6 virus-negative stapes footplates. Osteoprotegerin mRNA expression was significantly lower in the TNF-alpha-positive specimens (P < .0001) that was independent from virus positivity. CONCLUSION: Detection of TNF-alpha mRNA demonstrates activated osteoclast functions and inflammatory pathways in otosclerotic stapes footplates associated with measles virus presence. Increased expression of TNF-alpha and its action on RANK production inhibits the protective functions of osteoprotegerin on normal bone turnover in the otic capsule.

Adult↗

Activated osteoclasts with CD51/61 expression in otosclerosis.

HYPOTHESIS: Stapes ankylosis is supposed to be a disease with variable histopathology caused by otosclerosis or pseudo-otosclerosis. Persistent measles virus infection of the otic capsule could induce reactivation of quiescent embryonic osteoclasts in otosclerosis. BACKGROUND: Presence of measles virus RNA was demonstrated in the footplates of otosclerotic patients by reverse-transcription polymerase chain reaction (RT-PCR). Histology of active otosclerosis is featured by the presence of numerous osteoclasts with unknown phenotype. METHODS: Nucleic acid was extracted from stapes footplates of clinically otosclerotic patients (n = 261). Genomic RNA of measles virus was amplified by RT-PCR. Amplification results were correlated to postoperative histologic and CD51/61 specific immunohistologic findings. A parallel alcalic phosphatase activity assessment was performed to evaluate the metabolic activity of osteoclasts in each section. RESULTS: Among 261 stapes fixation cases, 175 otosclerotic stapes contained measles virus RNA. Histology for virus negative stapes (n = 86) represented nonotosclerotic, degenerative disorders. Histologically confirmed otosclerosis was featured by the presence of osteoclasts with renewed, embryonic phenotype. In otosclerosis, alcalic phosphatase activity was significantly higher compared with nonotosclerotic stapes ankylosis (P < .001). CONCLUSION: The presence of CD51/61 positive osteoclasts in otosclerotic bone containing viral sequences provides the basis for an inflammatory bone remodeling disorder. Otosclerosis is a disease caused by persistent measles virus infection and reactivation of resting embryonic osteoclasts in the otic capsule.

Adult↗

Effects of human papillomavirus type 16 oncoproteins on survivin gene expression.

Survivin has recently been identified as a novel member of the inhibitor of apoptosis (IAP) gene family. The product of this gene not only suppresses apoptosis but also controls cell division. Survivin is undetectable in most terminally differentiated normal tissues but is expressed in embryonic and fetal organs and is present in most malignant tumours. Human papillomaviruses (HPV) are thought to play an important role in the development of cervical cancer. By interfering in the cell cycle, the viral oncoproteins (E6 and E7) can induce the immortalization of the host cell. The transcriptional effects of the HPV-16 E6 and E7 proteins on the survivin promoter in transiently transfected cell lines using luciferase tests were examined. HPV-16 E6, but not E7, was found to significantly transactivate the survivin promoter. Experiments performed in different cancer cell lines and with different E6 mutants indicated that the effect of E6 on the survivin promoter is largely dependent on p53 status. In accordance with this, the p53 tumour suppressor protein downregulated the expression of survivin. As E6 is able to interact with p53 and induces its ubiquitin-dependent degradation, it appears that the transactivation effect of E6 on survivin is mediated by the p53 degradation pathway. Transduction of HPV-16 E6 and E7 into human embryonic fibroblast cells showed that the HPV oncoproteins can upregulate endogenous survivin mRNA. Importantly, cell cycle synchronization experiments showed that the effect of HPV-16 E6 on survivin transcription is independent of the cell cycle.

Apoptosis↗

Duration of HPV-associated risk for high-grade cervical intraepithelial neoplasia.

OBJECTIVE: To evaluate the duration of high-risk HPV-associated cancer risk. STUDY DESIGN: Patients who had had a routine diagnostic Hybrid Capture Tube Test (HCT) due to squamous cell abnormalities of the uterine cervix were followed-up until the endpoint of histologically diagnosed cervical intraepithelial neoplasia (CIN). RESULTS: Six hundred and thirty-eight women were followed during a cumulative follow-up of 16,423 patient months. The adjusted relative risk associated with the positive HR-HCT test for high-grade CIN/52.0 (20.9-19.2)/ proved to be higher than that of the cytological atypia/5.44 (2.52-11.77)/. At the end of the 30 months of follow-up the crude and adjusted risks for CIN2+ were 214.3 (28.4-1615.7) and 196.7 (25.4-1525.2), respectively in the HPV 16/18 group, and after 30 months, the crude and adjusted RR decreased to 57.6 (10.4-318.9) and 29.2 (5.02-170.0). In the groups of other high-risk types and possibly high-risk types the general tendency was the same. However, new CIN2+ cases were not detected after the 30th month of follow-up in these later groups. CONCLUSIONS: HPV16/18 associated relative risk is nearly 200 times higher than that of the HPV negative population and an outstanding risk persists with duration of about 30 months. The risk is manifested in progression to high-grade CIN lesions mainly within a 2 years interval after the first detection of HPV 16/18 infection.

Adult↗

The effect of mineral composition on the sorption of cesium ions on geological formations.

The sorption of cesium-137 on rock samples, mainly on clay rocks, is determined as a function of the mineral composition of the rocks. A relation between the mineral groups (tectosilicates, phyllosilicates, clay minerals, carbonates) and their cesium sorption properties is shown. A linear model is constructed by which the distribution coefficients of the different minerals can be calculated from the mineral composition and the net distribution coefficient of the rock. On the basis of the distribution coefficients of the minerals the cesium sorption properties of other rocks can be predicted.

Journal Article↗

Acid-base properties of bentonite rocks with different origins.

Five bentonite samples (35-47% montmorillonite) from a Sarmatian sediment series with bentonite sites around Sajóbábony (Hungary) is studied. Some of these samples were tuffogenic bentonite (sedimentary), the others were bentonitized tuff with volcano sedimentary origin. The acid-base properties of the edge sites were studied by potentiometric titrations and surface complexation modeling. It was found that the number and the ratio of silanol and aluminol sites as well as the intrinsic stability constants are different for the sedimentary bentonite and bentonitized tuff. The characteristic properties of the edges sites depend on the origins. The acid-base properties are compared to other commercial and standard bentonites.

Journal Article↗

Role of human papillomavirus (HPV) testing in the follow-up of patients after treatment for cervical precancerous lesions.

OBJECTIVE: To evaluate the role of human papillomavirus (HPV) testing in post-treatment follow-up of patients after therapeutic excision of the cervix due to positive screening tests. STUDY DESIGN: A hospital-based retrospective analysis was performed with prospective collection of patient data of women screened for cervical cancer at a Gynecologic Outpatient Clinic. Patients after therapeutic excision due to positive screening results were identified and followed up with HPV testing and serial cytology. RESULTS: After 61 treatment for cervicalis intraepithelialis neoplasia (CIN), high-risk HPV infection was detected during the post-treatment follow-up at 18 cases (29.5%), 10 of them had persisting cytological atypia (positive predictive value (PPV): 56%), 5 developed CIN (PPV: 28%). When the HPV test was negative (43 patients) in the post-treatment period, neither CIN nor persisting cytological atypia developed (negative predictive value (NPV): 100%) during 1201 patient months (median 26 months). CONCLUSIONS: A negative HPV test eliminates the risk of recurrent disease after treatment for CIN.

Adult↗

Histologic otosclerosis is associated with the presence of measles virus in the stapes footplate.

HYPOTHESIS: Persistent measles virus infection of the otic capsule is presumed to be one of the etiologic factors in otosclerosis. The viral pathogenesis of otosclerosis could be established only by correlative analysis: histologic examination of the stapes footplates and reverse-transcriptase polymerase chain reaction amplification of the viral RNA. At present, histologic analysis of the removed stapes footplates is the only appropriate method of distinguishing otosclerotic and nonotosclerotic stapes fixations. BACKGROUND: The presence of measles virus was shown in otosclerotic patients by reverse-transcriptase polymerase chain reaction amplification of the viral RNA and detecting the viral proteins by immunohistochemistry. METHODS: Nucleic acids (mRNA, vRNA, and DNA) were extracted from ankylotic stapes footplates of stapes fixation patients (n = 44). Measles virus genomic nucleoprotein RNA was amplified by seminested reverse-transcriptase polymerase chain reaction. Amplification results were correlated to postoperative histologic findings. RESULTS: Measles virus RNA was detectable only in histologically otosclerotic stapes footplates (n = 32). Histology for virus-negative footplates (n = 12) excluded otosclerosis. Virus-negative stapes footplates showed annular calcification (n = 8), bone resorption with increased numbers of hemosiderophages (n = 2), and mononuclear cell infiltration with osteolysis (n = 2). CONCLUSION: Stapes ankylosis is a heterogenous disease causing conductive hearing loss with different causes. Nonotosclerotic stapes fixations may belong to degenerative disorders with variable histopathology. Otosclerosis is an inflammatory disease resulting from persisting measles virus infection of the otic capsule.

Adult↗

Codetection of measles virus and tumor necrosis factor-alpha mRNA in otosclerotic stapes footplates.

HYPOTHESIS: Otosclerosis is a disease of unknown etiology causing conductive or sensorineural hearing loss. Persistent measles virus infection of the otic capsule is considered to be one of the etiologic factors in otosclerosis. BACKGROUND: Determinants of measles virus infection and reactive inflammation were studied in otosclerosis. The presence of measles virus was shown in otosclerotic patients by reverse-transcription polymerase chain reaction (RT-PCR) amplification of the viral RNA. No report is available, however, on the types and features of paracrine cytokines in otosclerosis. METHODS: Nucleic acid was extracted from stapes footplate samples of clinically otosclerotic patients. Measles virus nucleoprotein RNA was amplified by seminested RT-PCR. Tumor necrosis factor (TNF)-alpha mRNA expression was detected by RT-PCR in otosclerotic bone and was correlated with preoperative audiologic findings and measles virus positivity. RESULTS: Among 154 clinically otosclerotic patients, 99 stapes footplate specimens contained measles virus RNA. TNF-alpha mRNA was detectable in 88 virus-positive and in 6 virus-negative stapes footplates. There was no detectable TNF-alpha mRNA expression in virus negative cases. CONCLUSION: The etiologic role of measles virus in the pathogenesis of otosclerosis should be considered. Detection of TNF-alpha mRNA demonstrates activated osteoclast functions and inflammatory pathways in otosclerotic stapes footplates associated with measles virus presence. Virus-associated and virus-negative pathomechanisms of otosclerosis should be distinguished.

Adult↗

Two subgroups of stapes fixation: otosclerosis and pseudo-otosclerosis.

HYPOTHESIS: Stapes ankylosis is a disease with variable histopathology and can be caused by otosclerosis or pseudo-otosclerosis. Viral pathogenesis of otosclerosis could be established only by correlative analysis: histologic examination of the stapes footplate and reverse-transcriptase polymerase chain reaction (RT-PCR) amplification of the viral RNA. BACKGROUND: Presence of the RNA genome of measles virus was demonstrated in the footplates of clinically otosclerotic patients by RT-PCR, and also viral proteins were detected by immunohistochemistry. METHODS: Nucleic acids were extracted from ankylotic stapes footplates of clinically stapes fixation patients (n = 104). Measles virus genomic nucleoprotein (NP) RNA was amplified by seminested RT-PCR. Amplification results were correlated to postoperative histologic and audiologic findings. RESULTS: Measles virus RNA was detectable only in histologically otosclerotic stapes footplates (n = 67). Histology for virus negative footplates (n = 37) excluded otosclerosis. Virus negative stapes footplates showed nonotosclerotic, degenerative disorders. CONCLUSIONS: Stapes ankylosis is a heterogeneous disease causing conductive hearing loss with different etiologies. Nonotosclerotic stapes fixations could be established as pseudo-otosclerosis and may belong to nonspecific, degenerative disorders with variable and noncharacteristic histopathology. Otosclerosis is an inflammatory disease caused by persisting measles virus infection of the otic capsule.

Adult↗

Study of the change in the properties of Mn-bentonite by aging.

In this paper the structure and properties of fresh manganese(II)-bentonite was compared with that of an old substance. It was concluded that the oxidation state of Mn changed. This did not cause many changes in the scanning electron microscope (SEM) and in the X-ray diffraction (XRD) studies; caused minor changes in the Mn concentration (determined by XRF) and thermoanalytical and electron spectroscopy analysis (ESCA). The change in the oxidation state of manganese was indicated by the colors of the samples, the difference in the surface sites, titration curves, redox potentials, adsorption, and catalytic activity of the fresh and the old Mn-bentonite. Potentiometric titration data were evaluated by a surface complexation model using the FITEQL3.2 computer program. Stability constants of edge charge reactions and the number of aluminol, silanol, and edge sites were calculated. Potentiometric titration data of commercial and freshly made MnO2 were also evaluated; the calculated constants and site numbers were compared with that of found in literature. Catalytic and adsorption activity of the samples were also investigated. It was found that fresh Mn-bentonite does not adsorb valine, while the old one and MnO2 does. Fresh Mn-bentonite does not catalyze the decomposition of H2O2, while the old one, as well as MnO2 does.

Journal Article↗

IL-10 promoter nt -1082A/G polymorphism and human papillomavirus infection in cytologic abnormalities of the uterine cervix.

The role of A/G polymorphism at nucleotide -1082 in the interleukin-10 (IL-10) promoter was assessed by following the disease course of 253 patients who had had a routine diagnostic Hybrid Capture human papillomavirus (HPV) test because of cytologic or colposcopic abnormalities of the uterine cervix. At baseline, 97 (78%) of the 125 high-risk HPV-positive and 83 (65%) of the 128 HPV-negative patients had equivocal cytologic atypia classified as P3 by the Papanicolaou classification, and the rest of the patients had mild colposcopic atypia with cytologic results of no oncogenic significance. In the high-risk HPV-infected patients, the frequency distribution of the nt -1082 genotypes (A/A: 28%; A/G: 52%; G/G: 20%) did not differ significantly from that in the controls (A/A: 25%; A/G: 51%; G/G: 24%; p = 0.70). On the other hand, the nt -1082 G allele tended to decrease susceptibility to equivocal cytologic atypia unrelated to HPV infection (A/G: OR = 0.56 [95% CI: 0.31-1.02], G/G: OR = 0.27 [95% CI: 0.11-0.63], p for trend = 0.05). With respect to the development of high-grade cervical intraepithelial neoplasia (CIN), the established risk factors, such as high-risk HPV infection (RR = 104.6, 95% CI: 14.2-769.9) and cytologic atypia (RR = 9.6, 95% CI: 2.34-39.7) but not the various nt -1082 genotypes (A/A: reference; A/G: RR = 1.11 [95% CI: 0.59-2.08]; G/G: RR = 0.62 [95% CI: 0.25-1.50]) were found to increase the risk for high-grade CIN. In conclusion, the nt -1082 polymorphism had no influence on the early phase of cervical carcinogenesis but may determine different susceptibilities to cervical abnormalities unrelated to HPV infection.

Adenine↗

Measles virus prevalence in otosclerotic stapes footplate samples.

HYPOTHESIS: The cause of otosclerosis is still unknown. Persistent measles virus infection of the otic capsule is supposed to be one of the etiologic factors in otosclerosis. Chronic viral antigen expression on the surface of infected cells can induce a secondary autoimmune reaction against the otic capsule. BACKGROUND: In the past 15 years, some reports proposed the possible etiologic role of measles virus in otosclerosis. The presence of measles virus was shown in otosclerotic patients by reverse-transcriptase polymerase chain reaction amplification of the viral RNA, detecting the viral proteins by immunohistochemistry and detecting antimeasles immunoglobulin G in the perilymph samples. Many concerns were elicited by these results. METHODS: Nucleic acid was extracted from pulverized, frozen stapes footplate samples of otosclerotic patients. Measles virus RNA was amplified by reverse-transcriptase polymerase chain reaction: reverse transcription and the first round polymerase chain reaction amplification was performed by heat stable recombinant Thermus thermophilus polymerase, whereas in the nested round, polymerase chain reaction Taq-polymerase was used. Measles virus nucleoprotein RNA-specific oligonucleotide primers were used in these reactions. An Edmonston-type measles virus served as a positive control and cortical bone fragments or stapes superstructures served as negative controls. RESULTS: Among 34 otosclerotic patients, 20 stapes footplate samples contained measles virus RNA. Measles virus RNA was not detected in other bone specimens of the patients. CONCLUSION: The etiologic role of measles virus in the pathogenesis of otosclerosis should be considered. The 14 negative samples may be genetically determined otosclerotic cases.

Adult↗

Significant decrease of the enhancement/neutralization index in HIV patients during highly active antiretroviral therapy (HAART).

Authors studied the effect of highly active antiretroviral therapy (HAART) on balance of the antibodies that enhance or neutralize growth of HIV-1(IIIB) strain in MT-4 cells in the presence or absence of human complement. Sequential serum samples were collected from 28 patients in advanced stage of HIV disease before and during HAART. The balance of the enhancing and neutralizing antibodies was expressed by an index value (E/N I). Samples with an E/N I of <0.5 (twofold decrease in virus production) were considered as neutralizing, whereas samples with an E/N I>2.0 (twofold increase in virus production) were considered as enhancing. At the beginning of HAART serum samples from eight patients enhanced, and samples from only two patients neutralized the virus in the presence of complement, median (25th-75th percentile) value of E/N I was 1.32 (0.79-2.29). E/N I significantly (P<0.0001) dropped to 0.37 (0.19-0.57) during the follow-up period of 18.5 (10.5-23.5) months under HAART. Similar changes were detected when serum samples were tested with no complement added. The E/N I values were also markedly decreased when cultures inoculated with mixtures of HIV and purified IgG prepared from serum pools taken before and during HAART, respectively, were compared. In the last samples of 20/28 patients, neutralization was measured even in the presence of complement while enhancement was found with none of these samples. These findings suggest that HAART results in disappearance of enhancing antibodies and switches the E/N I toward neutralization.

Antibodies, Blocking↗

Differential patterns of human cytomegalovirus gene expression in various T-cell lines carrying human T-cell leukemia-lymphoma virus type I: role of Tax-activated cellular transcription factors.

Replication of human cytomegalovirus (HCMV) was investigated in various T-cell lines expressing the tax gene product of human T-cell leukemia-lymphoma virus type I (HTLV-I). Differential patterns of HCMV replication were found in HTLV-I-carrying cell lines. HCMV gene expression was restricted to the immediate-early genes in MT-2 and MT-4 cells, whereas full replication cycle of the virus was observed in C8166-45 cells. Productive HCMV infection induced a cytopathic effect resulting in the lysis of infected cells. The results of electrophoretic mobility shift assay (EMSA) showed high levels of NF-kappaB-, CREB/ATF-1-, and SRF-specific DNA binding activity in all Tax-positive cell lines. In contrast, SP1 activity could be detected only in C8166-45 cells. Using an inducible system (Jurkat cell line JPX-9), a dramatic increase in NF-kappaB, CREB/ATF-1, SRF, and SP1 binding activity, as well as productive HCMV infection, were observed upon Tax expression. Overexpression of SP1 in MT-2 and MT-4 cells converted HCMV infection from an abortive to a productive one. These data suggest that the stimulatory effect of Tax protein on HCMV in T cells is accomplished through at least five host-related transcription factor pathways. The results of this study provide possible mechanisms whereby HCMV infections might imply suppression of adult T-cell leukemia.

Cadmium Chloride↗