The Sin3A/MAD1 Complex, through Its PAH2 Domain, Acts as a Second Repressor of Retinoic Acid Receptor Beta Expression in Breast Cancer Cells.

Retinoids are essential in balancing proliferation, differentiation and apoptosis, and they exert their effects through retinoic acid receptors (RARs) and retinoid X receptors (RXRs). RARß is a tumor-suppressor gene silenced by epigenetic mechanisms such as DNA methylation in breast, cervical and non-small cell lung cancers. An increased expression of RARß has been associated with improved breast cancer-specific survival. The PAH2 domain of the scaffold protein SIN3A interacts with the specific Sin3 Interaction Domain (SID) of several transcription factors, such as MAD1, bringing chromatin-modifying proteins such as histone deacetylases, and it targets chromatin for specific modifications. Previously, we have established that blocking the PAH2-mediated Sin3A interaction with SID-containing proteins using SID peptides or small molecule inhibitors (SMI) increased RARß expression and induced retinoic acid metabolism in breast cancer cells, both in in vitro and in vivo models. Here, we report studies designed to understand the mechanistic basis of RARß induction and function. Using human breast cancer cells transfected with MAD1 SID or treated with the MAD SID peptide, we observed a dissociation of MAD1, RARα and RARß from Sin3A in a coimmunoprecipitation assay. This was associated with increased RARα and RARß expression and function by a luciferase assay, which was enhanced by the addition of AM580, a specific RARα agonist; EMSA showed that MAD1 binds to E-Box, similar to MYC, on the RARß promoter, which showed a reduced enrichment of Sin3A and HDAC1 by ChIP and was required for the AM580-enhanced RARß activation in MAD1/SID cells. These data suggest that the Sin3A/HDAC1/2 complex co-operates with the classical repressors in regulating RARß expression. These data suggest that SIN3A/MAD1 acts as a second RARß repressor and may be involved in fine-tuning retinoid sensitivity.

Periodontal health of the geriatric population in old-age homes of Delhi, India.

BACKGROUND: Periodontal disease is one of the leading causes of tooth loss in the geriatric population. Assessment of periodontal disease in a population is an important step in planning effective prevention and control programs for periodontal disease. Therefore, a study was carried out in old-age homes of Delhi to assess the periodontal status of 65-74-year-old elderly and recommend interventions to improve their periodontal health. MATERIALS AND METHODS: A cross-sectional study was conducted among 464 elderly from old-age homes of Delhi. Periodontal health status of the participants was determined using the WHO oral health assessment form. Community Periodontal Index (CPI) and loss of attachment (LOA) were recorded. Collected data were analyzed using SPSS version 23. Chi-square test was used to determine statistically significant difference among CPI scores and LOA according to age and gender. P ≤ 0.05 was considered statistically significant. RESULTS: The result of the study showed that 25.4% of the elderly had healthy periodontium, 71.1% had a periodontal pocket of 6 mm or more, and 2.40% had a pocket depth of 4-5 mm. Around 36% had 6-8 mm LOA and 34.70% had 9-11 mm LOA. The difference between CPI scores among gender and age group was not significant (P = 0.20, P = 0.096). However, the difference among gender for LOA was found significant (P = 0.014). CONCLUSION: The results from this study show that periodontal health of elderly residing in old-age homes is very poor. The periodontal status of this population can be enhanced by special collaborative efforts from the government and various nongovernmental organizations toward preventive and curative periodontal health services.

Comparison of Expression of Chemokine Receptor 4 in Maternal Decidua and Chorionic Villi in Women with Spontaneous Miscarriages and Women Opting for Termination of Viable Pregnancies.

BACKGROUND: Early pregnancy losses can be a distressing experience both for the parents and the treating clinician. We aim to explore the role of chemokine receptor 4 (CXCR4) in early pregnancy losses by comparing its expression among patients with spontaneous miscarriages and patients undergoing termination of viable pregnancies for unwanted pregnancies. AIM: The aim of the study was to investigate the expression of CXCR4 in early pregnancy losses and correlate the various clinical parameters with differential expression of the above receptor in the chorionic villi and maternal decidua. STUDY AND SETTING: The present study is a case-"control study done in a tertiary care center. METHODOLOGY: Fifty patients attending outdoor and antenatal clinic of the hospital aged 18-40 years with spontaneous miscarriage under 20 weeks of gestational age were included as cases and compared with fifty females of comparable age group (18-40 years) seeking medical termination of pregnancy as controls. Chorionic villi and decidua obtained from the cases and controls were analyzed for CXCR4 expression. STATISTICAL ANALYSIS: The results were analyzed using mean ± standard deviation, percentiles values, Chi-square test, and P value to determine the association of CXCR4 expression in decidua and chorionic villi of cases versus controls. RESULTS: CXCR4 expression was significantly downregulated in cases as compared to the controls with P < 0.001. The mean normalized ratio of CXCR4 expression to housekeeping gene (ß Actin) expression in the case group was 1.607 ± 1.108 and in the control group, it was 2.506 ± 1.457. There was a strong correlation between the expression of CXCR4 and maternal age. With increasing age, the expression of CXCR4 was more downregulated in both the cases and control groups (P < 0.001). The expression of CXCR4 was elevated in controls as compared to cases in <30 years age group (P = 0.009). CXCR4 expression was higher in primigravida than in multigravida (P = 0.001), and as the number of previous miscarriages increased, the expression of CXCR4 was found to be decreased (P = 0.021). CONCLUSION: CXCR4 expression is significantly reduced in women with spontaneous miscarriages in comparison with viable pregnancies. and possibly, therapies targeted at increasing the expression of CXCR4 can be used as a treatment modality for management of spontaneous miscarriages.

Hyperhomocysteinemia and low vitamin B12 are associated with the risk of early pregnancy loss: A clinical study and meta-analyses.

One-carbon metabolism is crucial for the maintenance of healthy pregnancy and alterations in this pathway have been associated with various pregnancy-related complications. Therefore, the present study was conducted to test the hypothesis that the altered folic acid, vitamin B12 and homocysteine levels are associated with the risk of early pregnancy loss (EPL). Plasma folic acid, vitamin B12 and homocysteine levels were analyzed in 83 females with EPL and 70 healthy pregnant females in their first trimester. Further, meta-analyses of folic acid, vitamin B12 and homocysteine were also performed involving various eligible studies. Results from our case-control study and meta-analysis showed that folic acid deficiency is not associated with the risk of EPL. On the other hand, low vitamin B12 and hyperhomocysteinemia were individually found to be significant risk factors for EPL in the present study (P < .01, P < .05, respectively) and meta-analysis as well (P < .001, P < .05, respectively). Vitamin B12 deficiency in combination with hyperhomocysteinemia was a more serious risk factor for EPL (Odds Ratio = 4.98, P = 0.002). Therefore, we conclude that vitamin B12 deficiency and elevated homocysteine levels are independent risk factors for EPL, and of higher risk when combined. The assessment of vitamin B12 and homocysteine levels may serve as a good screening marker for EPL risk.

Dental students' tooth shade selection ability in relation to years of dental education.

BACKGROUND AND OBJECTIVES: Perfect tooth shade selection is indispensable for successful esthetic dental restorations. Shade matching is a complex and multidimensional process that involves the cognitive ability of students. Hence, the aim of the present study was to assess and compare the shade matching ability of undergraduate dental students in various years of dental education. METHODS: A cross-sectional study was conducted among 150 students enrolled in all five class years of the Bachelor of Dental Surgery course in a dental college in India. Each enrolled participant was presented with two exercises to assess shade matching ability. In the first exercise, basic shade matching ability of the students was assessed by a shade tab matching in a bench setting using Vitapan Classical shade guide. In the second exercise, the participants were asked to perform intraoral tooth color matching to evaluate their ability of shade matching in a clinical setup. Data was analyzed using SPSS version 21 and descriptive statistics were applied. Chi-square test was applied to find out significant differences among years of education. RESULTS: For Exercise 1, 53 participants (35.30%) showed fair color matching ability in bench setting, 26.70% (n = 40) showed good ability, 22.70% (n = 34) demonstrated an excellent ability, whereas 15.30% (n = 23) had a poor ability of color matching. For Exercise 2, where clinical color matching ability of the students was analyzed, 34% (n = 51) obtained fair scores, 33.30% (n = 50) obtained good scores, 26% (n = 39) obtained excellent scores, whereas 6.70% (n = 10) of the participants had poor scores. CONCLUSION: This study showed that the clinical performance of dental students for shade matching improved as the years of dental education increased. Also, better outcomes were seen in clinical setting as compared to in vitro conditions.

Fostering cognizance of organ donation: An education-based approach.

INTRODUCTION: The knowledge of health professionals and trainees is of great importance as they could be very effective sources of motivation for the general population toward organ donation. So, a study was planned to improve the perceptions of students and faculty about organ donation. MATERIALS AND METHOD: A program-based educational intervention was implemented in a dental institute by a medical professional. It was attended by 168 participants, including interns, postgraduate students, and faculty members. A self-administered questionnaire consisting of 27 questions about knowledge, attitude, and practice (KAP) of organ donation was used. Statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) software Version 23, IBM. The difference in knowledge and attitude according to various demographic factors was determined by applying independent t-test and analysis of variance (ANOVA) test. A Chi-square test was used to assess the association between demographic variables and willingness to sign organ donor card. P < 0.05 was considered statistically significant. RESULT: The mean knowledge score of the study participants was 9.6 and the mean attitude score was 3.4 at the end of educational program. When association between willingness to sign organ card was assessed with age and gender, it was found that no such association existed. Statistically significant difference was found among males and females when compared for knowledge (P = 0.006) scores and among education group when compared for attitude (P = 0.0238). CONCLUSION: The present educational intervention for improving the perceptions of students and faculty about organ donation was successful as the study population was able to achieve sound knowledge and good attitude level.

Testing of a dental student-administered multidisciplinary health promotion program.

BACKGROUND: A multidisciplinary approach involving healthcare students for health promotion has been recommended. With this view, the primary phase of the integrated health promotion program (IHPP) was designed and pilot tested. METHODS: A pre-post-intervention study was conducted among 55 housewives of two self-help groups in India. The intervention consisted of a motivational interview, interactive session with a nutritionist, group discussion, personal hygiene training, and an illustrative reinforcement leaflet. Interventions were provided by trained dental students. The evaluation was based on outcomes from six tools specifically tailored for the program. These were the health self-regulation self-efficacy scale (HSSS), visual analogue scale (VAS) for self-health perception, oral health knowledge and attitude questionnaire, motivational interview, group discussion, and personal hygiene demonstration test. RESULTS: Statistically significant change in mean pre- and postprogram scores in HSSS (P < 0.001), its two components, metacognitive component, action component, as well as VAS (P = 0.001) indicated a change in health-related perceptions in the participants. Mean oral health knowledge score (6.1), as well as attitude score (3.8), was fair. Most of the participants were able to demonstrate personal hygiene and tooth brushing correctly; take collective decisions about their health, plan changes in their diet, and resolve upon bringing about healthy changes in their lifestyle. CONCLUSION: The program evaluation indicated successful intervention and may be replicated in a larger population. Healthcare student population may be used in developing countries to bring about an attitude change in the underprivileged population through an IHPP.

Investigation of psoriasis skin tissue by label-free multi-modal imaging: a case study on a phototherapy-treated patient.

Background: Psoriasis is a systemic inflammatory disease characterized by epidermal proliferation in the skin. Altered lipid metabolism is considered to be a central factor in the psoriatic etiopathogenesis. Thus, it is necessary to visualize chemical specificity of the samples for better medical diagnosis and treatment. Here, we investigate its role in the development of psoriatic lesions, before and after ultraviolet phototherapy, in a case study. Methods: The distribution and morphology of different lipids and fibrous proteins in psoriatic (lesional) tissues were visualized by two complementary label-free imaging techniques: 1) non-linear microscopy (NLM), providing images of lipids/proteins throughout the skin layers at submicrometer resolution; and 2) mass spectrometry imaging (MSI), offering high chemical specificity and hence the detection of different lipid species in the epidermal and dermal regions. A conventional method of histological evaluation was performed on the tissues, with no direct comparison with NLM and MSI. Results: Psoriatic tissues had a higher lipid content, mainly in cholesterol, in both the epidermal and dermal regions, compared to healthy tissues. Moreover, the collagen and elastin fibers in the psoriatic tissues had a tendency to assemble as larger bundles, while healthy tissues showed smaller fibers more homogeneously spread. Although phototherapy significantly reduced the cholesterol content, it also increased the amounts of collagen in both lesional and non-lesional tissues. Conclusion: This study introduces NLM and MSI as two complementary techniques which are chemical specific and can be used to assess and visualize the distribution of lipids, collagen, and elastin in a non-invasive and label-free manner.

Near-field imaging of surface-plasmon vortex-modes around a single elliptical nanohole in a gold film.

We present scanning near-field images of surface plasmon modes around a single elliptical nanohole in 88 nm thick Au film. We find that rotating surface plasmon vortex modes carrying extrinsic orbital angular momentum can be induced under linearly polarized illumination. The vortex modes are obtained only when the incident polarization direction differs from one of the ellipse axes. Such a direct observation of the vortex modes is possible thanks to the ability of the SNOM technique to obtain information on both the amplitude and the phase of the near-field. The presence of the vortex mode is determined by the rotational symmetry breaking of the system. Finite element method calculations show that such a vorticity originates from the presence of nodal points where the phase of the field is undefined, leading to a circulation of the energy flow. The configuration producing vortex modes corresponds to a nonzero total topological charge (+1).

Altered crosstalk of estradiol and progesterone with Myeloid-derived suppressor cells and Th1/Th2 cytokines in early miscarriage is associated with early breakdown of maternal-fetal tolerance.

PROBLEM: Decline in myeloid-derived suppressor cells (MDSCs) and Th2 cytokines levels lead to early miscarriage (EM) but how the hormonal milieu of the body regulates MDSCs and Th1/Th2 cytokine balance is still a matter of investigation. METHOD OF STUDY: Peripheral blood and decidua samples were collected from 20 EM patients, and 20 healthy pregnant women opted for elective abortion. MDSCs and G-MDSCs levels were analyzed in peripheral blood mononuclear cells, and Th1/Th2 cytokines levels were determined in serum via flow cytometry. Estrogen (E2), Progesterone (P4), and Testosterone levels were measured via ELISA. Further, proliferation and apoptosis in decidual samples were checked via immunoblot/immunohistochemistry of estrogen receptor -α (ER-α), STAT-3/pSTAT-3, and caspase-3, respectively. RESULTS: Our results clearly indicate that in EM patients; decline in E2 and P4 significantly correlates with decline in MDSCs, particularly with subtype granulocytic MDSCs (G-MDSCs) and skewness of the Th1/Th2 cytokines balance toward Th1 response. Downregulation of ER- α and increased caspase-3 expression in endometrium decidua signifies poor endometrial receptivity in EM. STAT-3 activation regulates proliferation, differentiation and suppressive potency of MDSCs. In decidua of EM, significantly lower expression of pSTAT-3 indicates that these processes pertaining to MDSCs are compromised. CONCLUSION: Altogether, this unfavorable systemic milieu may drive toward early breakdown of maternal-fetal tolerance in EM. Therefore, regulated crosstalk of E2, P4 with MDSCs and balanced Th1/Th2 cytokines is prerequisite for successful pregnancy.

Distribution and prevalence of oral mucosal lesions in residents of old age homes in Delhi, India.

BACKGROUND: It has been seen that very less attention has been given to the oral health of the geriatric population residing in old age homes and as the oral mucosal lesions are a matter of concern for this growing population. Therefore, a study was done with the objective of finding the prevalence of oral mucosal lesions and the distribution of oral mucosal lesions among 65-74 year old residents of old age homes in Delhi, India. MATERIALS AND METHODS: A cross sectional study was done on 65-74 year old age group elders of old age homes in Delhi. A total of 464 subjects participated in the study. Oral Health Assessment Form, WHO was used for assessing oral mucosa. Clinical examination was performed using two mouth mirrors under natural illumination in a systematic manner. Data was processed and analyzed using SPSS version 23. RESULTS: Out of a total of 464 subjects, 291 (62.70%) were males and 173 (37.30%) were females. Oral mucosal lesions seen in the study subjects were malignant tumours, leukoplakia, lichen planus, ulcerations, ANUG, Abscess and candidiasis. Leukoplakia was seen in 70 subjects (15%) and was present on buccal mucosa in the majority. A malignant tumour was seen in 7 subjects (1.5%) and commonly seen area is floor of mouth. CONCLUSION: Prevalence of oral mucosal lesions among residents of old age homes shows the need for increased preventive and diagnostic measures for prevention and early identification of oro-mucosal lesions. Taking adequate care for oro-mucosal health of elderly people residing in old age homes is necessary.

Second harmonic generation for collagen I characterization in rectal cancer patients with and without preoperative radiotherapy.

Rectal cancer is treated with preoperative radiotherapy (RT) to downstage the tumor, reduce local recurrence, and improve patient survival. Still, the treatment outcome varies significantly and new biomarkers are desired. Collagen I (Col-I) is a potential biomarker, which can be visualized label-free by second harmonic generation (SHG). Here, we used SHG to identify Col-I changes induced by RT in surgical tissue, with the aim to evaluate the clinical significance of RT-induced Col-I changes. First, we established a procedure for quantitative evaluation of Col-I by SHG in CDX2-stained tissue sections. Next, we evaluated Col-I properties in material from 31 non-RT and 29 RT rectal cancer patients. We discovered that the Col-I intensity and anisotropy were higher in the tumor invasive margin than in the inner tumor and normal mucosa, and RT increased and decreased the intensity in inner tumor and normal mucosa, respectively. Furthermore, higher Col-I intensity in the inner tumor was related to increased distant recurrence in the non-RT group but to longer survival in the RT group. In conclusion, we present a new application of SHG for quantitative analysis of Col-I in surgical material, and the first data suggest Col-I intensity as a putative prognostic biomarker in rectal cancer.

X-radiation enhances the collagen type I strap formation and migration potentials of colon cancer cells.

Rectal cancer treatment still fails with local and distant relapses of the disease. It is hypothesized that radiotherapy could stimulate cancer cell dissemination and metastasis. In this study, we evaluated the effect of X-radiation on collagen type I strap formation potential, i.e. matrix remodeling associated with mesenchymal cell migration, and behaviors of SW480, SW620, HCT116 p53+/+ and HCT116 p53-/- colon cancer cells. We determined a radiation-induced increase in collagen type I strap formation and migration potentials of SW480 and HCT116 p53+/+. Further studies with HCT116 p53+/+, indicated that after X-radiation strap forming cells have an increased motility. More, we detected a decrease in adhesion potential and mature integrin ß1 expression, but no change in non-muscle myosin II expression for HCT116 p53+/+ after X-radiation. Integrin ß1 neutralization resulted in a decreased cell adhesion and collagen type I strap formation in both sham and X-radiated conditions. Our study indicates collagen type I strap formation as a potential mechanism of colon cancer cells with increased migration potential after X-radiation, and suggests that other molecules than integrin ß1 and non-muscle myosin II are responsible for the radiation-induced collagen type I strap formation potential of colon cancer cells. This work encourages further molecular investigation of radiation-induced migration to improve rectal cancer treatment outcome.

Maintaining the Social Flow of Evidence-Informed Palliative Care: Use and Misuse of YouTube.

This review article is aimed to explore the use of the social media website YouTube (www.youtube.com) as an evidence resource in palliative care, for patients and caregivers, students and professionals, and providers and policy-makers in developing countries' settings. The reviewed evidence reiterated the role of this social media website in palliative care practice, education and research in the area of cancer. Efficacy studies on impact of such media on palliative care delivery in developing countries are still lacking.

Smarter palliative care for cancer: Use of smartphone applications.

Smartphones are technologically advanced mobile phone devices which use software similar to computer-based devices as a user-friendly interface. This review article is aimed to inform the palliative care professionals, cancer patients and their caregivers about the role of smartphone applications (apps) in the delivery of palliative care services, through a brief review of existing literature on the development, feasibility, analysis, and effectiveness of such apps. There is a dearth need for sincere palliative care clinicians to work together with software professionals to develop the suitable smartphone apps in accordance with the family/caregivers' necessities and patients' biopsychosocial characteristics that influence the technology driven evidence informed palliative cancer care.

Prevalence of human papillomavirus infection & cervical abnormalities in HIV-positive women in eastern India.

BACKGROUND & OBJECTIVES: India has the third highest burden of HIV and highest number of cervical cancer in the world. A cross-sectional study was performed to determine the prevalence and types of human papillomavirus (HPV) infection, and the factors associated with HPV infection and abnormal cervical cytology in HIV-positive women attending the Antiretroviral Therapy (ART) Centre in a tertiary care hospital in eastern India. METHODS: We screened 216 HIV- positive women with Papanicolau smear cytology and HPV testing. HPV DNA was detected by using consensus primers followed by sequencing. RESULTS: Of the 216 HIV-positive women screened, 58 (26.85%) were HPV-positive; 56 (25.9%) were of high-risk (HR) HPV type. The most prevalent HPV type was HPV-16 (7.9%); non 16 and 18 HPV types were present in 17.6 per cent patients. Age ≤ 35 yr [(OR), 2.56 (1.26-5.19)], illiteracy [OR, 2.30 (1.19-4.46)], rural residence [OR, 3.99 (1.27-12.56)] and CD4 ≤ 350/µl [OR, 2.46 (1.26-4.83)] were associated with increased risk of acquisition of HPV. One hundred thirty nine (74.33%) patients had normal/ negative for intraepithelial lesions (NILM) cytology, three (1.60%) had atypical squamous cells of undetermined significance (ASCUS), 32 (17.11%) had low-grade squamous intraepithelial lesions (LSIL), 10 (5.35%) had high-grade squamous intraepithelial lesions (HSIL) and three (1.60%) had carcinoma cervix. WHO clinical Stage III and IV [OR, 2.83 (1.07-7.49)] and CD4 ≤ 350/µl [OR, 2.84 (1.30-6.20)] were risk factors for abnormal cytology. INTERPRETATION & CONCLUSIONS: Our study showed 26.85 per cent HPV positivity in HIV infected women in this region, with HPV-16 as the commonest genotype. Abnormal cervical cytology was seen in about 25 per cent women. Regular Pap smear screening as recommended by the National AIDS Control Organization will help in early detection of cervical abnormalities in HIV- positive women.

Spontaneous ovarian hyperstimulation syndrome in a triplet pregnancy.

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication, usually iatrogenic after ovulation induction. OHSS is a very rare event in spontaneously conceived pregnancies. Only few cases have been reported in literature to the best of our knowledge. We report a very rare case of spontaneous critical OHSS (according to classification of severity of OHSS as mentioned in Greentop guidelines no. 5, 2006) associated with triplet pregnancy in a 26-year-old woman suffering from severe abdominal pain, distension, and dyspnea. Our case highlights the importance of a strong suspicion for OHSS when a clinical presentation could not be explained by common medical conditions.

High incidence of zidovudine induced anaemia in HIV infected patients in eastern India.

BACKGROUND & OBJECTIVES: Zidovudine (ZDV) is the preferred nucleoside reverse transcriptase inhibitor in the first line antiretroviral regimen in India. It is known to be associated with life threatening toxicity like anaemia. This study was aimed at determining the prevalence of ZDV induced anaemia in HIV infected patients initiated on ZDV containing antiretroviral therapy regimen and also to find out the correlates, if any, for causing ZDV induced anaemia. METHODS: This retrospective study was carried in ART Centre, Sir Sunderlal Hospital, Banaras Hindu University, Varanasi between March 2005 to December 2007. HIV infected patients registered at ART Centre were treated according to guidelines of National AIDS Control Organization (NACO). Patients (n=1256) with haemoglobin (Hb)>8 g/dl were prescribed ZDV based antiretroviral therapy regimens. Patients developing anaemia (<8 g/dl) with other causes of anaemia excluded were recorded. Correlation of baseline characteristics (age, gender, haemoglobin levels, weight, CD(4) counts and WHO clinical stage) with risk of developing anaemia was also calculated. RESULTS: Two hundred three (16.2%) patients on ZDV regimen developed anaemia (<8 g%); 7.9 per cent (n=100) of these developed severe anaemia (<6.5 g%). Females were more prone to develop anaemia (P=0.026). Age, weight, WHO clinical stage and CD4 counts had no relation to development of anaemia. INTERPRETATION & CONCLUSION: High incidence of ZDV induced anaemia seen in this study indicates regular monitoring of patients, particularly women on ZDV based antiretroviral regimens.

Biosorption of Cr(VI) by immobilized biomass of two indigenous strains of cyanobacteria isolated from metal contaminated soil.

Biosorption of Cr(VI) using native strains of cyanobacteria from metal contaminated soil in the premises of textile mill has been reported in this paper. Biosorption was studied as a function of pH (1-5), contact time (5-180 min) and initial chromium ion concentration (5-20mg/l) to find out the maximum biosorption capacity of alginate immobilized Nostoc calcicola HH-12 and Chroococcus sp. HH-11. The optimum conditions for Cr(VI) biosorption are almost same for the two strains (pH 3-4, contact time 30 min and initial chromium concentration of 20mg/l) however, the biomass of Chroococcus sp. HH-11 was found to be more suitable for the development of an efficient biosorbent for the removal of Cr(VI) from wastewater, as it showed higher values of q(m) and K(f), the Langmuir and Freundlich isotherm parameters. Both the isotherm models were suitable for describing the biosorption of Cr(VI) by the cyanobacterial biosorbents.