COVID-19 vaccine hesitancy among health service providers: A single centre experience from Karachi, Pakistan.

OBJECTIVE: To assess the views of health service providers towards coronavirus disease 2019 vaccination with Cansino, Sinovac and Sinopharm vaccines. METHODS: The analytical cross-sectional study was conducted at the Sindh Institute of Urology and Transplantation, Karachi, in May and June 2021, and comprised doctors, nurses, technical staff, and medical social officers. Data was collected using a questionnaire, in Urdu and English languages, assessing determinants of hesitancy. Data was analysed using SPSS 19. RESULTS: Of the 331 subjects, 156(47%) were males and 175(53%) were females. Overall, 183(55%) subjects were aged <30 years, and 7(2%) were aged >60 years. Among the responders, 274(83%) were vaccinated, 49(15%) wanted to delay, and 8(2.4%) were outright refusers. Among the hesitant, 43(80%) were women, and 56(98%) were aged <40 years. Age, gender, occupational group and personal experience with the disease had significant correlations with vaccination status (p<0.05). Personal safety 202(74%) followed by the perception of official requirement 162(59%) were the prime reasons for getting vaccinated. No respondent cited religious inhibitions or social media as the reason behind vaccine refusal. CONCLUSIONS: A lack of trust in the safety and efficacy data of the available Chinese vaccines appeared as a factor inducing hesitancy. The resistance of younger respondents, especially trainee physicians, was a finding of concern since they form the backbone of the health system in the country.

Evaluation of Pharmacokinetics, and Bioavailability of Higher Doses of Tocotrienols in Healthy Fed Humans.

BACKGROUND: Tocotrienols has been known to lower serum lipid parameters below 500 mg/d, while increase lipid parameters at higher dose of 750 mg/d. δ-Tocotrienol has a novel inflammatory property of concentration-dependent inhibition and activation. Therefore, inhibition (anti-inflammatory) property of tocotrienols at low doses is useful for cardiovascular disease, whereas, activation (pro-inflammatory) property using high dose is found effective for treatments of various types of cancer. We have recently described plasma bioavailability of 125 mg/d, 250 mg/d and 500 mg/d doses of δ-tocotrienol in healthy fed subjects, which showed dose-dependent increases in area under the curve (AUC) and maximum concentration (Cmax). Hence, in the current study, higher doses of tocotrienols have used to analyze its effect on plasma pharmacokinetic parameters. AIMS: To evaluate the safety and bioavailability of higher doses (750 mg and 1000 mg) of annatto-based tocotrienols in healthy fed subjects. All four isomers (α-, ß-, γ-, δ-) of tocols (tocotrienols and tocopherols) present in the plasmas of subjects were quantified and analyzed for various pharmacokinetic parameters. STUDY DESIGN: An open-label, randomized study was performed to analyze pharmacokinetics and bioavailability of δ-tocotrienol in 6 healthy fed subjects. All subjects (3/dose) were randomly assigned to one of each dose of 750 mg or 1000 mg. Blood samples were collected at 0, 1, 2, 4, 6, 8 h intervals and all isomers of α-,ß-,γ-,δ-tocotrienols, and tocopherols in plasmas were quantified by HPLC. RESULTS: Oral administration of 750 and 1000 mg/d of tocotrienols resulted in dose-dependent increases in plasmas (ng/ml) AUCt0-t8 6621, 7450; AUCt0-∞ 8688, 9633; AUMC t0-∞ 52497, 57199; MRT 6.04, 5.93; Cmax 1444, 1592 (P<0.05), respectively, of δ-tocotrienol isomer. Moreover, both doses also resulted in plasmas Tmax 3.33-4 h; elimination half-life (t1/2 h) 2.74, 2.68; time of clearance (Cl-T, l/h) 0.086, 0.078; volume of distribution (Vd/f, mg/h) 0.34, 0.30; and elimination rate constant (ke; h-1) 0.25, 0.17, respectively of δ- tocotrienol isomer. Similar results of these parameters were reported for γ-tocotrienol, ß- tocotrienol, α-tocotrienol, δ-tocopherol, γ-tocopherol, and ß-tocopherol, except for α- tocopherol. CONCLUSIONS: This study has described pharmacokinetics using higher doses of 750 mg/d and 1000 mg/d of δ-tocotrienol. These results confirmed earlier findings that Tmax was 3-4 h for all isomers of tocotrienols and tocopherols except for α-tocopherol (6 h). These higher doses of tocotrienols were found safe in humans and may be useful for treatments of various types of cancer, diabetes, and Alzheimer's disease.

Interaction of HIF-1α and Notch3 Is Required for the Expression of Carbonic Anhydrase 9 in Breast Carcinoma Cells.

Expression of carbonic anhydrase 9 (CA9) is associated with poor prognosis and increased tumor aggressiveness and does not always correlate with HIF-1α expression. Presently, we analyzed the regulation of CA9 expression during hypoxia by HIF-1α, Notch3, and the von Hippel-Lindau (VHL) in breast carcinoma cells. Both HIF-1α and Notch3 were absolutely required for the expression of CA9 mRNA, protein, and reporter. Reciprocal co-immunoprecipitation of HIF-1α, Notch3 intracellular domain (NICD3), and pVHL demonstrated their association. The presence of common consensus prolyl hydroxylation and pVHL binding motifs (L(XY)LAP);LLPLAP(2191) suggested an oxygen-dependent regulation for NICD3. However, unlike the HIF-1α protein, NICD3 protein levels were not modulated with hypoxia or hypoxia-mimetic agents. Surprisingly, mutations of the common prolyl hydroxylation and pVHL binding domain lead to the loss of CA9 mRNA, protein, and reporter activity. Chromatin immunoprecipitation assay demonstrated the association of NICD3, HIF-1α, and pVHL at the CA9 promoter. Further, the NICD3 mutant defective in prolyl hydroxylation and subsequent pVHL binding caused a reduction in cell proliferation of breast carcinoma cells. We show here for the first time that the interaction of HIF-1α with NICD3 is important for the regulation of CA9 expression. These findings suggest that although CA9 is a hypoxia-responsive gene, its expression is modulated by the interaction of HIF-1α, Notch3, and VHL proteins. Targeting the expression of CA9 by targeting upstream regulators could be useful in cancer/stem cell therapy.

Lead exposure and its adverse health effects among occupational worker's children.

Lead exposure is an important environmental health problem particularly affecting the children of occupational workers living in the lead-contaminated environment. The objectives of the study were to find out the frequency, potential sources and adverse health effects of elevated blood lead level (BLL) in the children of lead-related occupational workers. It was a comparative cross-sectional study. A total of two hundred forty six children aged 1-6 years, comprising an equal number (n = 123) from lead smelters/battery recycle plant workers living close to the industries at Wah/Gujranwala, Pakistan (lead-exposed group) and those living 30 km away from the industrial area (controls) were included. Demographic and clinical data of each subject was collected. Blood lead analysis was carried out by using kits on the lead analyzer (3010 B ESA, USA). Biochemical tests of renal and hepatic profile were analyzed on Selectra E auto analyzer. The median age of children was 4 years; comprising of 69 boys and 54 girls. The lead-exposed children had significantly high BLLs median (range) 8.1 (1-20.9) microg/dL as compared to controls 6.7 (1-13.3) microg/dL (p 10 microg/dL) in 38 (31%) as compared with 14 (11%) in controls. Hematopoietic, renal, and hepatic functions were significantly impaired in the lead-exposed children. In conclusion, the children of lead-related occupational workers have significantly increased frequency (31%) of lead poisoning. The potential source of lead overexposure in these children may be indirect through father's clothes and contaminated environment at home. Increased lead accumulation adversely affects health of these children.

Evaluation of lead body burden in occupational workers by lead mobilization test.

OBJECTIVE: To determine total lead body burden by the Lead mobilization test (LMT) by measuring 4 hours urinary lead excretion in the lead exposed as compared to unexposed industrial workers after administration of 10 mg/Kg of dimercaptosuccinic acid and correlate it with blood lead levels, at Wah district Rawalpindi. METHODS: Total 149 males consisting of 87 lead exposed workers and 62 controls were included. Dimercaptosuccinic acid (DMSA), 10mg/kg body weight, was administered orally. Four hours urine specimens before and after DMSA administration were collected. Blood lead levels (BLL) were determined on 3010B ESA lead analyzer and urinary lead was measured on atomic absorption analyst 800 (Perkin Elmer). RESULTS: The lead exposed workers had high BLL median (range) 291 (90-611) ug/L as compared to controls 108 (10-310) ug/L (p=0.01). The occupational workers also revealed high DMSA-chelated urinary lead excretion (DMSA Pb-U) median (range) 28 (1.7-268) ug/4h as compared to controls 6 (1-27) ug/4h (p<0.01). Four hours DMSA Pb-U was significantly correlated with BLL (r=0.67), baseline Pb-U (r=0.54) and DMSA Pb-U/creatinine ratio (r=.81) in the lead exposed group (p<0.001). Increased lead exposure was detected in 43% of the subjects by using the WHO criteria for BLL while 54% were identified with LMT. Thirteen (15%) lead exposed workers had BLL more than OSHA permissible limits. CONCLUSION: Lead mobilization test is a more reliable diagnostic test than BLL for assessment of toxicologically active fraction of total lead body burden and imminent health risks in occupational workers.