A study on seroconversion following first & second doses of ChAdOx1nCoV-19 vaccine in central Kerala

Background & objectives: Vaccination against COVID-19 induces spike protein-binding IgG antibodies, a robust correlate of protection against COVID-19. This study was undertaken to assess the humoral response after completion of both the doses of ChAdOx1 nCoV vaccine in healthcare workers (HCWs) at a tertiary care health centre in India. Methods: A cross-sectional COVID-19 vaccine-induced antibody study was conducted among HCWs. IgG antibodies against spike protein were measured at least 28 days after the first dose and the second dose of vaccination in both SARS CoV-2 naïve and recovered HCWs. Mean and median antibody titre following each dose of vaccine and its association with age, gender, co-morbidities and factors such as exercise, stress and sleep deprivation were also explored. Results: Among the 200 vaccine recipients, 91.5 per cent showed seroconversion after the first dose and 99.5 per cent after the second dose. The mean titre after the second dose was significantly higher when compared to the first dose (12.68±4.17 vs. 9.83±6.3, P=0.001). More than half (54%) had high antibody titre ?12 S/Co (Signal/cut-off). Previous COVID-19 infection was the single most important factor influencing antibody production, where the mean titre just after a single dose [mean-17.81±5.94, median-20.5 (interquartile range [IQR]-3.7)] surpassed the titre after the second dose in SARS CoV-2 naïve individuals [mean-12.29±4.00, median-12.8 (IQR-3.7), P=0.001]. Furthermore, 28 per cent of vaccinees showed a reduction in titre after the second dose. The mean fall in titre was 2.25±1.40 and was more pronounced in males, the younger age group and those with previous COVID-19 infection. Interpretation & conclusions: ChAdOx1 nCov-19 vaccine after two doses elicited an excellent immune response. However, greater immunogenicity after the first dose was seen among those with previous COVID-19 infection, even surpassing the titre achieved by the second dose of vaccine in SARS CoV-2 naïve recipients. A fall in antibody titre after the second dose is a matter of concern and requires further studies.

Trastuzumab induced radiation recall dermatitis: an interesting case

Radiation recall dermatitis (RRD) is the appearance of skin reactions in previously irradiated skin which is triggered by the administration of certain drugs. Surgery, chemotherapy, and radiotherapy are the mainstay of treatment in breast cancer. RRD induced by trastuzumab has been rarely reported in India. This is a case report of a 56-year-old woman presented to the medical oncology outpatient department of our hospital with breast lump, and she was diagnosed to have human epidermal growth factor receptor 2 (HER-2/neu) positive invasive ductal carcinoma of left breast of stage T2N3cM0. She was treated with neoadjuvant chemotherapy, and she underwent modified radical mastectomy with axillary lymph node dissection. The treating oncologist was planned to start on adjuvant chemotherapy with injection trastuzumab for every four weeks, for 15 cycles. Patient received first dose of injection trastuzumab (450 mg) intravenously in the right (contralateral) arm and developed painful, swollen, erythematous blisters, and maculopapular rashes following the sharp linear borders of her previous radiation fields. She was reviewed by the medical oncologist and diagnosed as a rare case of RRD and treated with topical betamethasone cream. Causality assessment for RRD to trastuzumab was done using Naranjo and WHO-UMC scale and found to be in the category of probable and probable/ likely respectively.

To study the association of CSF leak in fronotbasal skull fractures classified with the Burstein抯 classification

Background: To study the association of CSF leak in Fronotbasal skull Fractures classified with the Burstein抯 Classification.Methods: A prospective study was conducted from November 2014 to May 2016 in patients admitted with head injuries to KIMSDU, Karad, Maharashtra. All data was retrieved using a standardized data collection form.Results: Out of the total 55 patients of frontobasal fracture, 39 (70.9%) were found to have CSF leak. Out of 39 patients with CSF leak 34 (61.8%) had Type I head injury, 3 (5.5%) had Type II head injury, and 2 (3.6%) had Type III head injury. Statistical analysis showed significant association between CSF leak and Burstein抯 classes of head injury patients (p< 0.05).Conclusions: It was found that patients who had Burstein Type I injuries had a higher chance of CSF leak and most post traumatic leaks could be managed conservatively.

Present and future biochemical markers of cardiac diseases

Biochemical markers play an important role in the diagnosis of myocardial injuries and adopting a therapy that would improve clinical outcome. The earliest biomarkers, such as alanine aminotransferase and lactate dehydrogenase, have become redundant with the development of more sensitive and specific assays for latest cardiac markers. This development of assays for new marker proteins has contributed to a greater understanding of the pathophysiology of the disease spectrum of many myocardial diseases

Effect of Giardia lamblia on duodenal disaccharidase levels in humans.

The study was conducted to detect the effect of giardiasis on human disaccharidase levels. Forty patients attending the medical outpatient department of PGIMER, Chandigarh were enrolled. Twenty patients, positive for Giardia lamblia comprised the study group while 20 patients negative for Giardia lamblia were taken as controls. Upper gastrointestinal endoscopy was performed in all patients. Estimation of lactase, sucrase, maltase and trehalase was done in biopsies. Histopathological investigation was carried out in all biopsy specimens after Haematoxylin and Eosin staining. Complaints of pain abdomen and bloating occurred commonly in giardiasis. Four biopsy samples in study group showed mild increase in lymphomononuclear infiltrate. Giardia lamblia was detected in 7 biopsies. Lactase levels were decreased significantly (p < 0.05) in giardiasis. Rest of the enzymes were comparable to the controls. No differences in the enzyme activities were observed between males and females in either group and with the duration of symptoms.

A monoclonal antibody-based test system for detection of Entamoeba histolytica-specific coproantigen.

BACKGROUND: Diagnosis of amebiasis based on stool microscopy or demonstration of anti-amebic antibodies has limitations. A diagnostic system based on demonstration of the parasite product in clinical specimens holds promise. METHODS: Murine monoclonal antibodies were developed against an Entamoeba histolytica-specific coproantigen. A monoclonal antibody (MoAb) 3D10 was employed in a double-antibody sandwich microELISA system for the detection of amebic coproantigen in fecal specimens. The system was evaluated in three groups of subjects: 63 patients with intestinal amebae, 27 with non-amebic parasitosis, and 57 apparently healthy controls. RESULTS: The MoAb 3D10 belonged to IgG1 isotype and recognized three antigens, with mol. wt. 36, 25 and 17 kDa in the crude extract of E. histolytica (HM1-IMSS), and an amebic coproantigen with MW 36 kDa in the stool supernatant from patients with intestinal amebae. The coproantigen was detected in the stool eluates of 56 (89%) patients with intestinal amebae and in none of the stool eluates from other subjects, thereby giving this system a sensitivity of 89% and specificity of 100% for the detection of intestinal amebae. CONCLUSIONS: This monoclonal antibody recognizes as intact epitope on the E. histolytica-specific coproantigen. The validity of the MoAb-based microELISA system needs to be established.

Anti-66 kDa antileishmanial antibodies as specific immunodiagnostic probe for visceral leishmaniasis.

A 66 kDa plasma membrane associated molecule of promastigotes of Leishmania donovani (MHOM/IN/1978/UR6) was affinity purified under acidic conditions. Employing purified 66 kDa antigen in micro ELISA, 36 (97.3%) of the 37 patients of visceral leishmaniasis (bone marrow aspirates positive for Leishman Donovan bodies) had detectable levels of anti 66 kDa anti leishmanial antibodies. The sera of the patients confirmed to have visceral leishmaniasis had significantly (P < 0.001) higher optical density values (0.636 +/- 0.230) as compared to sera (OD 0.185 +/- 0.131) from patients clinically suspected to have visceral leishmaniasis (bone marrow aspirates negative for Leishman Donovan bodies). None of the 35 sera from apparently healthy subjects from non endemic area had anti 66 kDa antibodies. However, sera from one (8.3%) of the 12 healthy subjects, who was a first degree relative of a patient of visceral leishmaniasis and residing in an area endemic for visceral leishmaniasis, had anti 66 kDa antibodies. It is felt that detection of anti 66 kDa antibodies in a micro ELISA assay provides a highly sensitive and specific tool for confirming ongoing visceral leishmaniasis.

Evaluation of commercially available antacid tablets.

Antacids are commonly used for the treatment of acid peptic disease. There is a need to study the relative merits of various brands of antacids available commercially. Twenty three brands of antacid tablet preparations were evaluated with regard to their composition, cost, dispersion time, pH, neutralising capacity and time taken for neutralisation. The cost of various tablets ranged from Rs 0.13 to Rs. 1.48 per tablet and the dispersion time from 20 to 90 minutes. The pH of the dispersed tablet solution ranged from 5.7 to 9.5. The neutralising capacity varied between 8 to 169 meq/tablet and the neutralizing time between 20 and 45 minutes. The cost: neutralizing ratio was calculated and ranged from 102 to 9867 x 10(-3) Rs/meq. A scoring system with a maximum score of 12 has been devised. The study provides a guide for choosing a more potent, quick neutralising and low cost antacid preparation.

Detection of Entamoeba histolytica antigens in stool in amebiasis.

BACKGROUND: Stool microscopy, the conventional method of diagnosing intestinal amebiasis, fails to detect Entamoeba histolytica in more than 30-40% of clinically suspected cases. Demonstration of parasite products in clinical specimens has been suggested as an alternative. However, the usefulness of demonstrating amebic antigen in the stools of clinical cases needs to be assessed. METHODS: A double-antibody sandwich enzyme linked immunosorbent assay (ELISA) using anti-trophozoite antibodies to capture E histolytica specific coproantigen(s) was carried out on stools obtained from 31 patients with microscopically confirmed non-dysenteric amebic colitis, 18 patients with intestinal parasites other than E histolytica and 41 apparently healthy subjects. RESULTS: The assay detected E histolytica specific coproantigen(s) in stools of 23 (74.2%) of 31 subjects with non-dysenteric amebic colitis, none of 18 with other parasitic infections and 1 (2.4%) of 41 apparently healthy subjects. CONCLUSION: Our results provide evidence for the presence of E histolytica specific coproantigen(s) in stool eluates from patients with amebic infection; this finding can be exploited for confirming ongoing amebic infection. However, the sensitivity of the assay needs to be improved by the use of relevant monospecific/monoclonal antibodies.

Isolation & immunochemical characterization of diagnostically relevant antigens of Echinococcus granulosus.

Two hydatid specific polypeptides with molecular masses of 8 kDa and 116 kDa have been successfully isolated from E. granulosus hydatid cyst fluid using affinity chromatography. Sodium dodecyl sulphate polyacrylamide gel electrophoresis and western immunoblot analysis under reducing and denaturing conditions indicated the 116 kDa purified antigen to be a hetero-tetramer consisting of 45 kDa, 66 kDa, 75 kDa and 116 kDa subunits linked by disulphide bonds while the 8 kDa purified antigen was found to be a monomer polypeptide. Affinity purified 116 kDa molecule was heat-labile, sensitive to treatment with pronase, trypsin and pepsin and its immunoreactivity as assessed in enzyme linked immunosorbent assay remained unaltered on treatment with sodium metaperiodate. The affinity purified 8 kDa molecule was heat-stable, sensitive to proteolytic enzymes and also sodium metaperiodate oxidation. Lectin binding studies revealed that the 8 kDa molecule specifically bound Concanavalin A and Triticum vulgaris, and thus had varies; is directly proportional to-D-glucose and N-acetyl D-glucosamine sugar moieties. The immunoreactivity of both the antigens remained unaltered on treatment with lipase. However, biochemical estimation of total lipid content revealed the affinity purified 116 kDa antigen to contain 6.25 per cent total lipids suggesting it to be lipoproteinic in nature. The 8 kDa antigen had no detectable total lipids biochemically. All sera from patients confirmed to have hydatidosis recognised the 8 kDa and 116 kDa polypeptides. However, sera from seven subjects with other parasitic infections also recognised the 116 kDa antigen though not the 8 kDa antigen. The data suggested that the recognition of 8 kDa antigen of E. granulosus has potential for specific immunodiagnosis of hydatidosis.

Evaluation of antacid gel preparations available commercially in the Indian market.

A scoring system based on the neutralising capacity, cost efficiency and time of buffering of twenty four commercially available antacid gels was analysed. A gel scoring eight out of the ten points was considered as the best antacid. The study provides a practical guide in choosing a quick neutralizing and low cost antacid gel.

Variations in isoenzymes of cloned & uncloned axenic Entamoeba histolytica without bacterial association.

Five clones of axenic E. histolytica (HMI) grown as discrete colonies in semisolid agar medium were adapted in liquid medium and labelled as HMI-C121, HMI-C131, HMI-C143, HMI-C144 and HMI-C145. Isoenzymes of these 5 clones of E. histolytica (HMI) were investigated in starch gel electrophoresis. There were no differences in the electromobility of maleate NADP oxidoreductase and glucosephosphoisomerase amongst the five clones and uncloned cultures of axenic E. histolytica. The relative electromobility (rf) of a single phosphoglucomutase (PGM) band of uncloned Mexican E. histolytica (HMI) and Indian axenic E. histolytica (KCG: 0986: 11) cultures and cloned E. histolytica HMI-C121, HMI-C145 was 0.087 while a single PGM band of uncloned E. histolytica (NIH: 200) and cloned E. histolytica HMI-C131, HMI-C143 and HMI-C144 cultures had rf of 0.075. Isoenzyme characterization of four cloned HMI-C121, HMI-C131, HMI-C143, HMI-C144 cultures of axenic E. histolytica (HMI) revealed existence of three bands of hexokinase (HK). The additional third band of HK was located close to the place of application of lysate and had rf ranging from 0.11-0.14. The data indicated that parent axenic E. histolytica (HMI) consisted of several populations and each population expressed different isoenzyme pattern without an association of amoebic cultures with any bacterial species.

Monoclonal antibodies which inhibit in vitro cytotoxicity of axenic Entamoeba histolytica.

A panel of 12 independent hybridoma cell lines secreting monoclonal antibodies to axenic E. histolytica (HM1) have been developed. A hybridoma cell line P4 C4 P2 F8 C8 (clone C8) produced monoclonal antibodies (MoAb C8) of IgG1 isotype which recognised a 29 KD surface associated antigen of amoebic trophozoites in Western immunoblot. Immunofluorescent probing with MoAb C8 employing live and acetone fixed amoebic trophozoites indicated 29 KD molecule on the surface plasma membrane of E. histolytica trophozoites. The MoAb C8 also agglutinated the live amoebic trophozoites. Pretreatment of amoebic trophozoites with anti 29 KD monoclonal antibody significantly (P less than 0.01) inhibited in vitro cytotoxicity of amoebic trophozoites to the cultured baby hamster kidney (BHK-21) cells. MoAb recognised a 29 KD molecule of E. histolytica trophozoites which mediated cytotoxic potentials of the parasite. The absence or variable degree of expression of cytotoxic 29 KD molecule may possibly serve as a marker to differentiate virulent/avirulent populations or strains of E. histolytica.

Characterization of surface associated antigens of axenic Giardia lamblia trophozoites & their recognition by human sera.

Two surface associated antigens (GLSA-82 and GLSA-56) of axenically grown G. lamblia trophozoites (PI strain) were affinity purified from its sonic extract. Both GLSA-82 and GLSA-56 were heat labile, sensitive to treatment with pronase, trypsin and were also sodium metaperiodate modifiable as assessed by micro ELISA. Lectin binding studies revealed that GLSA-82 specifically bound concanavalin A and pokeweed mitogen, and had alpha-methyl mannoside and n-acetyl-B-d-glucosamine sugar moieties. However, GLSA-56 selectively bound Ricinus communis agglutinin and phytohaemagglutinin, and had B-d-galactose and n-acetyl-B-d-galastosamine as sugar moieties. Human sera obtained during acute G. lamblia infection recognised GLSA-82 and GLSA-56 antigens. However, the antibody levels to GLSA-82 were significantly lower (P less than 0.05) during active giardiasis infection. Such surface associated antigens may be target of antiparasitic immune responses and thus, may modulate disease processes.

Prevention of malaria-induced foetal abnormalities following immunization of mice with Plasmodium berghei merozoite antigen.

Pre-pregnancy immunization of Swiss albino mice with merozoite antigen of P. berghei entrapped in multilamellar phosphatidyl choline liposomes resulted in (i) increased prepatent period, (ii) either no or low parasitaemic levels, (iii) reduced mortality, and (iv) normal foetal and placental development, upon challenge with P. berghei on 13th gestational day. The unimmunized animals which received either phosphate buffered saline or empty multilamellar phosphatidyl choline liposomes before pregnancy developed high parasitaemic and 30-40 per cent animals died before parturition while 60-70 per cent unimmunized animals revealed foetal abnormalities such as low body weight and larger spleen size. Placentae of unprotected animals had hyperplasia of trophoblastic membrane and plugging of placental sinusoids with parasitized erythrocytes and malarial pigments. The data suggest that prior immunization of animals with merozoite antigen entrapped in multilamellar phosphatidyl choline liposomes could abrogate the ill effects induced by malaria infection under the stress of pregnancy.

Immunobiological studies with mycobacterial ribonucleic acid-protein complex: Part II--Mechanism of protective immunity against experimental tuberculosis.

Passive transfer of protective antituberculous immunity against LD50 dose of M. tuberculosis H37Rv was found to be mainly mediated by immune T-cells harvested from spleens of donor mice immunized with Myc. RNA-P-FIA complexes as monitored by indices of percent survival, root specific lung weight, lung density and by bacterial enumeration from different organs. Treatment of immune T-cells with anti-Thy 1.2. monoclonal antibodies plus complement prior to passive transfer, completely abrogated its protective effect thereby confirming their protective nature. Passive transfer of immune sera as well as immune T + B cells did not induce any enhancement in protective immunity.

Immunobiological studies with mycobacterial ribonucleic acid-protein complex: Part I--Immune responses and protective role against experimental tuberculosis.

Ribonucleic acid (RNA) isolated from M. tuberculosis H37Ra was found to be native in nature as determined by hyperchromicity studies using ribonuclease. Mycobacterial RNA-protein (Myc. RNA-P) when injected as RNA-P-FIA complexes induced weak humoral immune responses and strong cell-mediated immune (CMI) responses which were directed against Myc. RNA. Protection comparable to BCG was induced in mice immunized with RNA-FIA complexes against LD50 dose of M. tuberculosis as monitored by increased survival rates, decreased lung density, root specific lung weight (RSLW) and by decreased viable counts of M. tuberculosis in lung, liver and spleen of immunized mice. Enzymatic degradation studies revealed Myc. RNA component to specifically mediate protection while the protein component was found ineffective.