Mohammed Salahuddin

Dr. Mohammed Salahuddin

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2021 in Nature and Science of Sleep
Verified
Journal Article
Open access
PDF file
MMMd Dilshad Manzar
Md Dilshad Manzar
MSMohammed Salahuddin
Mohammed Salahuddin
Seithikurippu R. Pandi-PerumalSeithikurippu R. Pandi-Perumal
Seithikurippu R. Pandi-Perumal
Ahmed S BaHammamAhmed S BaHammam
Ahmed S BaHammam
Background: High perceived stress and anxiety disorders are usually comorbid with each other, with stress often sequentially preceding the development of anxiety. While prior findings showed a causal role of sleep problems in anxiety, no study has assessed the role of insomnia as a mediator in the relationship between stress and anxiety. Methods: A cross-sectional study on university students (n = 475, age = 21.1+2.6 years) was conducted over 3 months. Participants completed self-report measures of Leeds Sleep Evaluation Questionnaire-Mizan (LSEQ-M), Perceived Stress Scale-10 (PSS-10), generalized anxiety disorder-7 scale (GAD-7), and a sociodemographic tool. The mediation effect model given by Baron and Kelly was used to determine the relationship. Results: The prevalence of insomnia and anxiety disorder was 43.6% and 21.9%, respectively. Stress was significantly associated with LSEQ-M (insomnia measure) (b = − .44, SE = 0.16, p< 0.01), and high levels of anxiety (b = 0.25, SE = 0.03, p < 0.01). The indirect effect of stress on anxiety through LSEQ-M (insomnia measure) was significant (95% confidence interval [0.01, 0.04]). However, the indirect effect of anxiety on stress through LSEQ-M (insomnia measure) was non-significant (95% confidence interval [− .01, 0.04]). Conclusions: Students having higher perceived stress levels and comorbid insomnia were also likely to have a higher anxiety level.

28 July 2021 in PLOS Neglected Tropical Diseases
Verified
Journal Article
Open access
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ECElizabeth A. Cromwell
Elizabeth A. Cromwell
JOJoshua C. P. Osborne
Joshua C. P. Osborne
TUThomas Raymond Unnasch
Thomas Raymond Unnasch
MBMaria-Gloria Basanez
Maria-Gloria Basanez
KGKATHERINE GASS
KATHERINE GASS
DPDavid M. Pigott
David M. Pigott
Recent evidence suggests that, in some foci, elimination of onchocerciasis from Africa may be feasible with mass drug administration (MDA) of ivermectin. To achieve continental elimination of transmission, mapping surveys will need to be conducted across all implementation units (IUs) for which endemicity status is currently unknown. Using boosted regression tree models with optimised hyperparameter selection, we estimated environmental suitability for onchocerciasis at the 5 × 5-km resolution across Africa. In order to classify IUs that include locations that are environmentally suitable, we used receiver operating characteristic (ROC) analysis to identify an optimal threshold for suitability concordant with locations where onchocerciasis has been previously detected. This threshold value was then used to classify IUs (more suitable or less suitable) based on the location within the IU with the largest mean prediction. Mean estimates of environmental suitability suggest large areas across West and Central Africa, as well as focal areas of East Africa, are suitable for onchocerciasis transmission, consistent with the presence of current control and elimination of transmission efforts. The ROC analysis identified a mean environmental suitability index of 0·71 as a threshold to classify based on the location with the largest mean prediction within the IU. Of the IUs considered for mapping surveys, 50·2% exceed this threshold for suitability in at least one 5 × 5-km location. The formidable scale of data collection required to map onchocerciasis endemicity across the African continent presents an opportunity to use spatial data to identify areas likely to be suitable for onchocerciasis transmission. National onchocerciasis elimination programmes may wish to consider prioritising these IUs for mapping surveys as human resources, laboratory capacity, and programmatic schedules may constrain survey implementation, and possibly delaying MDA initiation in areas that would ultimately qualify.

Verified
Journal Article
Open access
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MSMohammed Salahuddin
Mohammed Salahuddin
FMFakhri Mahdi
Fakhri Mahdi
Jason ParisJason Paris
Jason Paris
Human immunodeficiency virus (HIV) is associated with co-morbid affective and stress-sensitive neuropsychiatric disorders that may be related to dysfunction of the hypothalamic-pituitary-adrenal (HPA) stress axis. The HPA axis is perturbed in up to 46% of HIV patients, but the mechanisms are not known. The neurotoxic HIV-1 regulatory protein, trans-activator of transcription (Tat), may contribute. We hypothesized that HPA dysregulation may contribute to Tat-mediated interactions with oxycodone, a clinically-used opioid often prescribed to HIV patients. In transgenic male mice, Tat expression produced significantly higher basal corticosterone levels with adrenal insufficiency in response to a natural stressor or pharmacological blockade of HPA feedback, recapitulating the clinical phenotype. On acute exposure, HIV-1 Tat interacted with oxycodone to potentiate psychomotor and anxiety like-behavior in an open field and light-dark transition tasks, whereas repeated exposure sensitized stress-related psychomotor behavior and the HPA stress response. Pharmacological blockade of glucocorticoid receptors (GR) partially-restored the stress response and decreased oxycodone-mediated psychomotor behavior in Tat-expressing mice, implicating GR in these effects. Blocking corticotrophin-releasing factor (CRF) receptors reduced anxiety-like behavior in mice that were exposed to oxycodone. Together, these effects support the notion that Tat exposure can dysregulate the HPA axis, potentially raising vulnerability to stress-related substance use and affective disorders.

1 May 2020 in Neurobiology of Stress
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Journal Article
Open access
Jason ParisJason Paris
Jason Paris
PLPhilippe Liere
Philippe Liere
SKSarah Kim
Sarah Kim
FMFakhri Mahdi
Fakhri Mahdi
MBMeagan E. Buchanan
Meagan E. Buchanan
KHKurt F. Hauser
Kurt F. Hauser
Pregnane steroids, particularly allopregnanolone (AlloP), are neuroprotective in response to central insult. While unexplored in vivo, AlloP may confer protection against the neurological dysfunction associated with human immunodeficiency virus type 1 (HIV-1). The HIV-1 regulatory protein, trans-activator of transcription (Tat), is neurotoxic and its expression in mice increases anxiety-like behavior; an effect that can be ameliorated by progesterone, but not when 5α-reduction is blocked. Given that Tat's neurotoxic effects involve mitochondrial dysfunction and can be worsened with opioid exposure, we hypothesized that Tat and/or combined morphine would perturb steroidogenesis in mice, promoting neuronal death, and that exogenous AlloP would rescue these effects. Like other models of neural injury, conditionally inducing HIV-1 Tat in transgenic mice significantly increased the central synthesis of pregnenolone and progesterone's 5α-reduced metabolites, including AlloP, while decreasing central deoxycorticosterone (independent of changes in plasma). Morphine significantly increased brain and plasma concentrations of several steroids (including progesterone, deoxycorticosterone, corticosterone, and their metabolites) likely via activation of the hypothalamic-pituitary-adrenal stress axis. Tat, but not morphine, caused glucocorticoid resistance in primary splenocytes. In neurons, Tat depolarized mitochondrial membrane potential and increased cell death. Physiological concentrations of AlloP (0.1, 1, or 10 nM) reversed these effects. High-concentration AlloP (100 nM) was neurotoxic in combination with morphine. Tat induction in transgenic mice potentiated the psychomotor effects of acute morphine, while exogenous AlloP (1.0 mg/kg, but not 0.5 mg/kg) was ameliorative. Data demonstrate that steroidogenesis is altered by HIV-1 Tat or morphine and that physiological AlloP attenuates resulting neurotoxic and psychomotor effects.

5 September 2018 in Journal of Ethnicity in Substance Abuse
Verified
Journal Article
Closed access
MMMd Dilshad Manzar
Md Dilshad Manzar
MSMohammed Salahuddin
Mohammed Salahuddin
TKTufail Ahmad Khan
Tufail Ahmad Khan
SSShowkat Ahmad Shah
Showkat Ahmad Shah
MAMajed Alamri
Majed Alamri
Ahmed S BaHammamAhmed S BaHammam
Ahmed S BaHammam
This study investigated the psychometric properties of the Insomnia Severity Index (ISI) in substance-using Ethiopian adults. A simple random sampling of houses and a purposive sampling selection was performed in Mizan city, Ethiopia (n = 406). Participants completed the ISI and a meta-cognition questionnaire and sociodemographic information. IBM SPSS software with Amos was used for data analysis. There was no major ceiling or floor effect in the ISI scores. The internal consistency (Cronbach’s alpha = 0.68 and 0.78) and internal homogeneity (moderate to strong item-total ISI score correlations; r ≥ 0.47) were adequate. All of the ISI (item as well as total) scores correlated with the meta-cognition total scores (r = 0.16–0.44; p < .01). The exploratory factor analysis results were heterogeneous. However, the confirmatory factor analysis favored a 2-factor model. The ISI has good psychometric validity among Ethiopian adults with substance use.

30 April 2021 in Viruses
Verified
Journal Article
Open access
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MSMohammed Salahuddin
Mohammed Salahuddin
FMFakhri Mahdi
Fakhri Mahdi
SSSuresh Ponnayyan Sulochana
Suresh Ponnayyan Sulochana
Jason ParisJason Paris
Jason Paris
Human immunodeficiency virus (HIV) is associated with neuroendocrine dysfunction which may contribute to co-morbid stress-sensitive disorders. The hypothalamic-pituitary-adrenal (HPA) or -gonadal (HPG) axes are perturbed in up to 50% of HIV patients. The mechanisms are not known, but we have found the HIV-1 trans-activator of transcription (Tat) protein to recapitulate the clinical phenotype in male mice. We hypothesized that HPA and/or HPG dysregulation contributes to Tat-mediated interactions with oxycodone, an opioid often prescribed to HIV patients, in females. Female mice that conditionally-expressed the Tat1–86 protein [Tat(+) mice] or their counterparts that did not [Tat(−) control mice] were exposed to forced swim stress (or not) and behaviorally-assessed for motor and anxiety-like behavior. Some mice had glucocorticoid receptors (GR) or corticotropin-releasing factor receptors (CRF-R) pharmacologically inhibited. Some mice were ovariectomized (OVX). As seen previously in males, Tat elevated basal corticosterone levels and potentiated oxycodone’s psychomotor activity in females. Unlike males, females did not demonstrate adrenal insufficiency and oxycodone potentiation was not regulated by GRs or CRF-Rs. Rather OVX attenuated Tat/oxycodone interactions. Either Tat or oxycodone increased anxiety-like behavior and their combination increased hypothalamic allopregnanolone. OVX increased basal hypothalamic allopregnanolone and obviated Tat or oxycodone-mediated fluctuations. Together, these data provide further evidence for Tat-mediated dysregulation of the HPA axis and reveal the importance of HPG axis regulation in females. HPA/HPG disruption may contribute vulnerability to affective and substance use disorders.