Characterization of partially purified catalase from camel (Camelus dromedarius) liver

The liver of camel has high level of catalase (32,225 units/g tissue) as commercially used bovine liver catalase. For the establishment of the enzyme, the rate of catalase activity was linearly increased with increase of the catalase concentration and incubation time. The procedure of partial purification of catalase from camel liver included preparation of crude extract, ammonium sulphate precipitation and chromatography on diethylaminoethyl cellulose (DEAE)-Sepharose. One peak catalase activity was obtained from the chromatography. The enzyme had optimum pH of 7.0. Camel liver catalase had broad optimum temperature between 25 and 40°C and was stable up to 25°C. The Km and Vmax values were found to be 22.7 mM H2O2/ml and 7.9 units/ml, respectively. All metal cations partially inhibited camel liver catalase with the exception of Hg2+ which had strong inhibitory effect, whereas 95% of its activity was lost at 1.0 mM. In conclusion, camel liver catalase can be used as an alternative commercial bovine liver catalase.Key words: Camel, liver, catalase, purification, characterization

On the numerical simulation of population dynamics with density-dependent migrations and the Allee effects

In this paper, the variational iteration method (VIM) and the Adomian decomposition method (ADM) are presented for the numerical simulation of the population dynamics model with density-dependent migrations and the Allee effects. The convergence of ADM is proved for the model problem. The results obtained by these methods are compared to the exact solution. It is found that these methods are always converges to the right solutions with high accuracy. Furthermore, VIM needs relative less computational work than ADM

Drivers' perceptions of unsafe driving behaviors and their countermeasures: a study in Saudi Arabia

There is an increased public concern about the role of aggressive driving and "road rage" in crashes and traffic fatalities. There is no general agreement as to what constitutes aggressive driving. Consequently, the objective of the study was to survey of the perceptions on the specific unsafe driving acts. Perceptions and beliefs of drivers about unsafe and aggressive driving actions and their countermeasures are presented in this paper. The study primarily looked at the wide range of driver attitudes about speeding and other forms of unsafe driving behavior. The study was conducted in Jeddah, the second largest city of Saudi Arabia by interviewing a sample of 300 drivers. The results indicated that the drivers, in general, prefer to drive at higher speeds and could be considered as more aggressive compared to the drivers in the United States. The most dangerous reported driving act was "drive thru red light", followed by "racing another driver". Only 23% of the drivers thought that it was dangerous to drive over 30 km of the legal speed limits. The most often seen unsafe driving action was "speeding (70%), followed by "driving too closely (57%), "failing to use turn signals (53%), "drive inattentively (50%)", and "running red lights (43%)". The main causes of unsafe driving behaviors were "being in a hurry/time pressure (66%)", "aggressive behavior of others (52%)", and "refusing traffic rules (51%)". The countermeasure that was viewed to be the most effective in reducing unsafe driving behaviors was assigning more traffic police officers (66%). The study revealed that, more than half the drivers believed that more frequent ticketing (60%), doubling or tripling fines (54%), and doubling the length of imprisonment (53%) would be effective in reducing unsafe driving behavior

Blood neurofilament light levels predict non-relapsing progression following anti-CD20 therapy in relapsing and primary progressive multiple sclerosis: Findings from the ocrelizumab randomised, double-blind phase 3 clinical trials

BACKGROUND: Neurofilament light chain (NfL), a neuronal cytoskeletal protein that is released upon neuroaxonal injury, is associated with multiple sclerosis (MS) relapsing activity and has demonstrated some prognostic ability for future relapse-related disease progression, yet its value in assessing non-relapsing disease progression remains unclear. METHODS: We examined baseline and longitudinal blood NfL levels in 1421 persons with relapsing MS (RMS) and 596 persons with primary progressive MS (PPMS) from the pivotal ocrelizumab MS trials. NfL treatment-response and risk for disease worsening (including disability progression into the open-label extension period and slowly expanding lesions [SELs] on brain MRI) at baseline and following treatment with ocrelizumab were evaluated using time-to-event analysis and linear regression models. FINDINGS: In persons from the RMS control arms without acute disease activity and in the entire PPMS control arm, higher baseline NfL was prognostic for greater whole brain and thalamic atrophy, greater volume expansion of SELs, and clinical progression. Ocrelizumab reduced NfL levels vs. controls in persons with RMS and those with PPMS, and abrogated the prognostic value of baseline NfL on disability progression. Following effective suppression of relapse activity by ocrelizumab, NfL levels at weeks 24 and 48 were significantly associated with long-term risk for disability progression, including up to 9 years of observation in RMS and PPMS. INTERPRETATION: Highly elevated NfL from acute MS disease activity may mask a more subtle NfL abnormality that reflects underlying non-relapsing progressive biology. Ocrelizumab significantly reduced NfL levels, consistent with its effects on acute disease activity and disability progression. Persistently elevated NfL levels, observed in a subgroup of persons under ocrelizumab treatment, demonstrate potential clinical utility as a predictive biomarker of increased risk for clinical progression. Suppression of relapsing biology with high-efficacy immunotherapy provides a window into the relationship between NfL levels and future non-relapsing progression. FUNDING: F. Hoffmann-La Roche Ltd

Contemporary Bioethics: Islamic Perspective

Human Genetics; Theory of Medicine/Bioethics; Ethic

Association Between Voice Handicap Index and Reflux Symptom Index: A cross-sectional study of undiagnosed general and teacher cohorts in Saudi Arabia

Objectives: This study aimed to assess potential associations between self-reported symptoms of laryngopharyngeal reflux (LPR) and voice disorders among two undiagnosed cohorts in Saudi Arabia. Methods: This cross-sectional study was conducted from February to April 2017 in Khobar, Saudi Arabia. Validated Arabic versions of the Reflux Symptom Index (RSI) and 10-item Voice Handicap Index (VHI-10) were distributed to 400 teachers at 13 schools and 300 members of the general population attending an ear, nose and throat clinic in Khobar. Scores of >13 and >11 on the RSI and VHI-10 indicated a potential subjective diagnosis of LPR and voice disorders, respectively. Results: A total of 446 individuals took part in the study, including 260 members of the general population (response rate: 86.7%) and 186 teachers (response rate: 46.5%). The mean age was 32.5 years. In total, 62.2% complained of voice and/or reflux problems, with the remaining 37.8% not reporting/unaware of any problems in this regard. Among the teachers, 30.6% and 18.3% had positive RSI and VHI-10 scores, respectively, while 43.1% and 14.6% of the individuals from the general population had positive RSI and VHI-10 scores, respectively. Overall, VHI-10 scores were significantly associated with RSI scores (P <0.001). Conclusion: A significant association between RSI and VHI-10 scores suggests that there may be an association between LPR and voice disorders. These tools would therefore be a valuable method of monitoring patients; however, they cannot be used to confirm a diagnosis. Thus, more detailed studies are needed to confirm this association using a larger sample size.Keywords: Voice Disorders; Laryngopharyngeal Reflux; Hoarseness; Diagnostic Self Evaluation; School Teachers; Saudi Arabia

Improved diagnostics and further investigations of bovine mastitis caused by mollicutes

The ultimate aims of this thesis were to improve the diagnostics of mollicute-associated mastitis and confirm their pathogenic role in bovine mastitis. Three types of experiments were carried out on improving diagnostics of mollicute associated mastitis (PCR, real time PCR-high resolution melting curve analysis (HRM), and Enzyme linked immunosorbent assay (ELISA)) on 368 milk samples from a single commercial dairy farm in South Australia (Farm 1), and were compared to conventional culture. Samples were collected purposively only from cows with high somatic cell count and/or mastitis treatment failure. For some tests (e.g. ELISA) samples from a second farm (n=40) in South Australia were also used (Farm 2). Novel primers of 16S ribosomal RNA were used in the PCR and HRM methodologies. A phylogenetic relationship among field isolates of mycoplasmas and acholeplasmas was created based on 16S rRNA sequences. An indirect ELISA, based on a recombinant fragment of the Mycoplasma immunogenic lipase A (MilA) protein was tested in milk for M. bovis antibodies, and compared to PCR and culture. For estimation of the pathogenic role of mollicutes associated with bovine mastitis, milk herd test data was analysed from 7,560 cow-tests. Four types of media (glycerol (GLY) + dimethyl sulphoxide (DMSO), gelatine + DMSO, foetal bovine serum (FBS) + DMSO, and original milk (CON)) were used to test the survivability of Mycoplasma bovis over time at 1, 2, 4, 8 and 16 weeks freezing in domestic and -80º C freezers. Very high prevalence of mollicutes was detected in the 288 purposively sampled cows (76.7%) using species-specific PCR. Culture was inferior in detecting infected milk samples (25.1%). The novel universal PCR demonstrated best concordance with species-specific PCR (Cohen’s Kappa= 0.747 ± 0.031). The novel HRM analysis was able to discriminate between four of the field isolates of Mycoplasma spp. and Acholelasma laidlawii. Mycoplasma bovis antibodies were detected only in 68/291 samples (23.4%). The co-infection with two or more mollicutes had a similar effect on milk composition to other major mastitis pathogens. Long-term stored milk samples should be enriched with some of the cryopreservatives used in this thesis. All cryopreservatives improved the survivability of M. bovis in milk samples stored under freezing conditions. The combination of GLY and DMSO resulted in significantly higher recovery rates at week 16, compared to CON with 57.1% (95% CI = 21.43–133.34) and 19.1% (95% CI = 11.73–60.27), respectively. The use of GLY and DMSO should therefore be encouraged for use as a cryoprotectant for M. bovis at − 20 and − 80 °C. Microbiological and molecular techniques used in this thesis should result in improved diagnostics of mollicute-associated mastitis providing rapid and accurate screening techniques. This should become a cornerstone in control strategies of mollicute-associated bovine mastitis.Thesis (Ph.D.) -- University of Adelaide, School of Animal and Veterinary Sciences, 201