Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
41
result(s) for
"Ngalamika, Owen"
Sort by:
Viral and immunological markers of HIV-associated Kaposi sarcoma recurrence
by
Ngalamika, Owen
,
Vally, Faheema
,
Kawimbe, Musonda
in
Acquired immune deficiency syndrome
,
Adult
,
Africa South of the Sahara
2021
Kaposi sarcoma (KS) is an AIDS-defining angio-proliferative malignancy highly prevalent in Sub-Saharan Africa. The main objective of this study was to determine the factors associated with recurrence of HIV-associated KS. We recruited a cohort of individuals on antiretroviral therapy who were in remission for HIV-associated KS after undergoing cytotoxic cancer chemotherapy. Collected variables included sociodemographic and clinical parameters, cytokines and chemokines, HIV viral loads, and CD4 counts. Compared to individuals who had KS recurrence, IL-5 was significantly higher at time of follow-up in individuals who had sustained remission (22.7pg/ml vs . 2.4pg/ml; p = 0.02); IL-6 was significantly higher at baseline and time of follow-up in individuals who had sustained remission, (18.4pg/ml vs . 0pg/ml; p = 0.01) and (18.0pg/ml vs . 0.18pg/ml; p = 0.03) respectively; IP-10 was significantly lower at baseline and at time of follow-up in individuals who had sustained remission, (534pg/ml vs . 920pg/ml; p = 0.04) and (446pg/ml vs .1098pg/ml; p = 0.01) respectively; while HIV viral load was significantly lower at baseline and at time of follow-up in individuals who had sustained remission, (0copies/ml vs . 113copies/ml; p = 0.004) and (0copies/ml vs . 152copies/ml; p = 0.025) respectively. Plasma levels of IL-5, IL-6, and IP-10 are associated with recurrence of HIV-associated KS, while persistently detectable HIV viral loads increase the risk of KS recurrence.
Journal Article
Vaccines to prevent COVID-19: A living systematic review with Trial Sequential Analysis and network meta-analysis of randomized clinical trials
by
Petersen, Johanne Juul
,
von Rohden, Elena
,
Ong, Giok
in
Adverse events
,
Bias
,
Biology and Life Sciences
2022
COVID-19 is rapidly spreading causing extensive burdens across the world. Effective vaccines to prevent COVID-19 are urgently needed.
Our objective was to assess the effectiveness and safety of COVID-19 vaccines through analyses of all currently available randomized clinical trials. We searched the databases CENTRAL, MEDLINE, Embase, and other sources from inception to June 17, 2021 for randomized clinical trials assessing vaccines for COVID-19. At least two independent reviewers screened studies, extracted data, and assessed risks of bias. We conducted meta-analyses, network meta-analyses, and Trial Sequential Analyses (TSA). Our primary outcomes included all-cause mortality, vaccine efficacy, and serious adverse events. We assessed the certainty of evidence with GRADE. We identified 46 trials; 35 trials randomizing 219 864 participants could be included in our analyses. Our meta-analyses showed that mRNA vaccines (efficacy, 95% [95% confidence interval (CI), 92% to 97%]; 71 514 participants; 3 trials; moderate certainty); inactivated vaccines (efficacy, 61% [95% CI, 52% to 68%]; 48 029 participants; 3 trials; moderate certainty); protein subunit vaccines (efficacy, 77% [95% CI, -5% to 95%]; 17 737 participants; 2 trials; low certainty); and viral vector vaccines (efficacy 68% [95% CI, 61% to 74%]; 71 401 participants; 5 trials; low certainty) prevented COVID-19. Viral vector vaccines decreased mortality (risk ratio, 0.25 [95% CI 0.09 to 0.67]; 67 563 participants; 3 trials, low certainty), but comparable data on inactivated, mRNA, and protein subunit vaccines were imprecise. None of the vaccines showed evidence of a difference on serious adverse events, but observational evidence suggested rare serious adverse events. All the vaccines increased the risk of non-serious adverse events.
The evidence suggests that all the included vaccines are effective in preventing COVID-19. The mRNA vaccines seem most effective in preventing COVID-19, but viral vector vaccines seem most effective in reducing mortality. Further trials and longer follow-up are necessary to provide better insight into the safety profile of these vaccines.
Journal Article
Clinical, immune and genetic risk factors of malaria-associated acute kidney injury in Zambian children: A study protocol
by
Ngalamika, Owen
,
Mwakazanga, David
,
McCulloch, Mignon
in
Acute Kidney Injury - etiology
,
Acute Kidney Injury - genetics
,
Acute Kidney Injury - immunology
2025
Acute kidney injury (AKI) affects nearly half of children with severe malaria and increases the risk of adverse outcomes such as death and poor cognitive function. The pathogenesis and predictors of malaria-associated acute kidney injury (MAKI) are not fully described. This study aims to determine the clinical, immune, and genetic correlates of risk to AKI in Zambian children admitted with malaria. In addition, we intend to assess a modified renal angina index (mRAI), kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and soluble urokinase receptor (suPAR), when done on the first day of admission, for the ability to predict AKI two days later (day 3) in children admitted with malaria.
This is an unmatched case-control study with a nested prospective observational study. A case-to-control ratio of 1:1 is used and 380 children with malaria and aged less than 16 years are being recruited from two hospitals in Zambia. Eligible children are recruited after obtaining written informed consent. Recruitment occurs during the malaria season and began on 6th March 2024 and will continue until July 2025. AKI is defined using the 2012 KIDGO AKI creatinine criteria, and cases are defined as children admitted with malaria who develop AKI within 72 hours of admission, while controls are children admitted with malaria but with no AKI. Serum creatinine is collected on Day 1 within 24 hours of admission, on Day 3 and then again on discharge or day 7, whichever comes sooner. Baseline biomarker concentrations will be determined using the Luminex multiplex Elisa system or high-sensitivity ELISA. SPSS version 29 will be used for data analysis. Descriptive statistics and inferential statistical tests will be run as appropriate. A p ≤ 0.05 will be considered as significant. The sensitivity, specificity, and estimates of the area under the curve (AUC) for the renal angina score will be determined.
Journal Article
Cells of the Innate and Adaptive Immune Systems in Kaposi’s Sarcoma
by
Ngalamika, Owen
,
Munsaka, Sody
in
Acquired immune deficiency syndrome
,
Adaptive immunity
,
AIDS
2020
Kaposi’s sarcoma (KS) is an angioproliferative malignancy whose associated etiologic agent is the Kaposi’s sarcoma-associated herpesvirus (KSHV). KS is the most prevalent malignancy among HIV-infected individuals globally and is considered an AIDS-defining malignancy. The different forms of KS including HIV-associated KS, iatrogenic (immunosuppression-related) KS, and classical KS in elderly males suggest that immune cell dysregulation is among the key components in promoting KS development in KSHV-infected individuals. It is therefore expected that different cell types of the immune system likely play distinct roles in promoting or inhibiting KS development. This narrative review is focused on discussing cells of the innate and adaptive immune systems in KSHV infection and KS pathogenesis, including how these cells can be useful in the control of KSHV infection and treatment of KS.
Journal Article
The effects of HIV and oncogenic human papillomavirus on the tumor immune microenvironment of penile squamous cell carcinoma
2024
Penile squamous cell carcinoma (PSCC) occurs more frequently in some developing countries compared to developed countries. Infection with HIV and/or high-risk human papillomavirus (hrHPV) are risk factors for penile cancer development. The tumor microenvironment of PSCC may predict prognosis and may inform on the best targets for immunotherapy. We evaluated the immune microenvironment of penile tumors histologically, and determined whether and/or how HIV and/or hrHPV infections affect this tumor microenvironment. We conducted a prospective analytical cross-sectional study in which penile cancer tumors from 35 patients presenting at the University Teaching Hospital in Lusaka, Zambia were histologically staged and assessed for presence of tumor infiltrating immune cells and expression of immune checkpoints. Immunohistochemistry was used to evaluate immune checkpoints and infiltrating immune cells, while multiplex real-time polymerase chain reaction was used for hrHPV genotyping. The median age of all participants was 55 years. About 24% had advanced histological stage, 83% were HIV + , and 63% had hrHPV detected in their tumors using multiplex real-time polymerase chain reaction. PDL1 expression was significantly higher in HIV - participants than HIV + participants (p = 0.02). Tumors with multiple hrHPV infections had a significantly higher number of cells expressing TIM3 than those with one hrHPV (p = 0.04). High grade tumors had a significantly higher infiltrate of FoxP3 + cells (p = 0.02), CD68 + cells (p = 0.01), CD163 + cells (p = 0.01), LAG3 + cells (p = 0.01), PD1 + cells (p = 0.01) and TIM3 + cells (p = 0.03) when compared with low grade tumours. There was significant moderate to strong positive correlation of cells expressing PD1 and LAG3 (⍴ = 0.69; p = 0.0001), PD1 and TIM3 (⍴ = 0.49; p = 0.017) and TIM3 and LAG3 PDL1 (⍴ = 0.61; p = 0.001). In conclusion, the tumor microenvironment of penile squamous cell carcinoma seems to be affected by both HIV and HPV infections. TIM3 appears to be a potential therapeutic target in PSCC patients with hrHPV infections.
Journal Article
Salt sensitivity and myocardial fibrosis: unraveling the silent cardiovascular remodeling
by
Ngalamika, Owen
,
Mutengo, Katongo Hope
,
Masenga, Sepiso K.
in
Angiotensin
,
Animal models
,
Antihypertensives
2025
Salt sensitivity is a well-recognized contributor to cardiovascular risk, traditionally linked to elevated blood pressure. However, emerging evidence suggests that high dietary sodium may also promote myocardial fibrosis through non-hemodynamic mechanisms, including the activation of redox-sensitive and profibrotic pathways. Despite growing mechanistic insights, the connection between salt sensitivity and myocardial fibrosis remains underexplored, particularly in human studies. This review synthesizes current experimental and translational evidence linking dietary salt intake to myocardial fibrosis, with a focus on molecular signaling cascades, tissue sodium compartmentalization, and the clinical implications of salt-sensitive physiology. We discuss the relevance of these mechanisms to the development of diastolic dysfunction and their potential contribution to heart failure with preserved ejection fraction (HFpEF). In addition, we highlight findings from animal models and the emerging application of sodium magnetic resonance imaging ( 23 Na-MRI) as a novel imaging tool for visualizing myocardial sodium overload and its association with fibrotic remodeling. Finally, we explore future therapeutic strategies that extend beyond traditional antihypertensives, including mineralocorticoid receptor antagonists (MRAs), angiotensin receptor blockers (ARBs), sodium-glucose cotransport 2 (SGLT2) inhibitors, and sodium-modulating interventions. Together, these insights offer new opportunities for early detection and targeted treatment in salt-sensitive cardiovascular disease.
Journal Article
Antibody profiling and predictive modeling discriminate between Kaposi sarcoma and asymptomatic KSHV infection
2024
Protein-level immunodominance patterns against Kaposi sarcoma-associated herpesvirus (KSHV), the aetiologic agent of Kaposi sarcoma (KS), have been revealed from serological probing of whole protein arrays, however, the epitopes that underlie these patterns have not been defined. We recently demonstrated the utility of phage display in high-resolution linear epitope mapping of the KSHV latency-associated nuclear antigen (LANA/ORF73). Here, a VirScan phage immunoprecipitation and sequencing approach, employing a library of 1,988 KSHV proteome-derived peptides, was used to quantify the breadth and magnitude of responses of 59 sub-Saharan African KS patients and 22 KSHV-infected asymptomatic individuals (ASY), and ultimately to support an application of machine-learning-based predictive modeling using the peptide-level responses. Comparing anti-KSHV antibody repertoire revealed that magnitude, not breadth, increased in KS. The most targeted epitopes in both KS and ASY were in the immunodominant proteins, notably, K8.1 29−56 and ORF65 140-168 , in addition to LANA. Finally, using unbiased machine-learning-based predictive models, reactivity to a subset of 25 discriminative peptides was demonstrated to successfully classify KS patients from asymptomatic individuals. Our study provides the highest resolution mapping of antigenicity across the entire KSHV proteome to date, which is vital to discern mechanisms of viral pathogenesis, to define prognostic biomarkers, and to design effective vaccine and therapeutic strategies. Future studies will investigate the diagnostic, prognostic, and therapeutic potential of the 25 discriminative peptides.
Journal Article
Immune correlates of Mycobacterium Tuberculosis patients in Zambia stratified by HIV serostatus and level of immunity-a cross-sectional analytical laboratory based study
by
Ngalamika, Owen
,
Lakhi, Shabir
,
Lungu, Patrick
in
Adult
,
Biology and Life Sciences
,
CD4 antigen
2022
People living with HIV (PLHIV) co-infected with tuberculosis (TB) have a distinct clinical presentation and poorer treatment outcomes compared to HIV-seronegative TB patients. Excluding low CD4 count, innate immune factors associated with TB are not fully elucidated. We, therefore, characterised and compared the expression of IL-6, TNF-α, IFN-γ, and IL-10 in whole blood of treatment naïve TB patients stimulated with heat-killed Mycobacterium tuberculosis stratified by HIV status and the level of CD4 count.
We recruited 39 HIV seropositive and 31 HIV seronegative TB patients. Median (IQR) age was 35(28-42) years and 31(25-36) years respectively, and a majority had pulmonary tuberculosis i.e. 38(95%) and 30(97%), respectively. The two groups were significantly different in the distribution of CD4 count, 563 [465-702.5 cells/mm3] vs 345 [157-483 cell/mm3] in HIV negative vs HIV positive respectively p = <0.001. Post stimulation, the expression of IL-6 in HIV negative TB patients was significantly higher than in the HIV positive 16,757366 [8,827-23,686 pg/ml] vs. 9,508 [5,514-15,008 pg/ml], respectively; p = 0.0360. TNF-α and IFN-γ were highly expressed in HIV negative TB patients compared to the HIV positive though not statistically significant. We only observed higher expression of IL-6 in HIV negative patients in comparison to the HIV positive when stratified by level of CD4 counts as < 500 and ≥ 500 cell/mm3 for both cohorts. 21,953 [8,990-24,206 pg/ml] vs 9,505 [5,400-15,313 pg/ml], p value = 0.0585 in patients with CD4 count < 500 cell/mm3 and 13,168 [7,087-22,584 pg/ml] vs 10,413 [7,397-14,806 pg/ml], p value = 0.3744 for patients with CD4 count of ≥ 500 cell/mm3 respectively. We found a positive pairwise correlation between TNF-α -alpha and IL-6 in both HIV positive and HIV negative patients, r = 0.61 (95% CI 0.36-0.72; p < 0.0001) and r = 0.48 (95% CI 0.15-0.68; p = 0.005) respectively. The IFNγ/IL-10 ratio was higher in HIV negative when compared to HIV positive individuals, 0.052 [0.0-0.28] vs 0.007 [0-0.32] respectively; p = 0.05759. IL-6 independently reduced the probability of TB/HIV, Adjusted odds ratio 0.99, p value 0.007.
This study suggests that HIV seronegative TB patients have a higher pro-inflammatory response to MTB than HIV seropositive TB patients. Further, it also shows that the level of CD4 influences immunomodulation. The findings suggest that the difference in cytokine expression may be responsible for the distinct patterns of TB presentation between HIV positive and HIV negative patient.
Journal Article
HIV, syphilis and sexual-risk behaviours’ prevalence among in-and out-of-school adolescent girls and young women in Zambia: A cross-sectional survey study
by
Mweemba, Mable
,
Munakampe, Margaret
,
Zyambo, Cosmas
in
Acquired immune deficiency syndrome
,
Adolescent
,
Adolescents
2024
In Zambia, 3.8% of young women and men aged 15-24 are HIV positive. However, like in most developing nations, HIV prevalence is higher among young women than young men (5.6% versus 1.8%). Despite the recognition of the rights of young people to sexual reproductive health (SRH) information and services, adolescent and young people (AYP) still face challenges in accessing healthcare in public health institutions including access to comprehensive knowledge on HIV/AIDs, HIV testing and contraceptives. The overall objective of the study was to collect baseline HIV, SRH and gender based violence (GBV) data at district level to inform the design of interventions targeting adolescent girls and young women (AGYW) aged 10-24 years in 20 districts of Zambia.
A cross-sectional, mixed-methods study was conducted in 20 districts of Zambia with the highest incidence of HIV. Data was collected between August and October 2022 with a total response rate of 92% (12,813/13960), constituting 5979 (46.7%) in-school and 6834 (53.3%) out-of-school participants.
Overall, Mwinilunga, Chinsali, Chisamba and Chembe districts had the highest number of respondents, while Sinazongwe and Mungwi districts contributed the least. The overall age distribution was such that 12.6% (n = 1617) of those interviewed were aged 10 to 14 years, 35.4% (n = 4536) were aged 15-19 years, and 52.0% (n = 6660) were aged 20-24 years. The overall mean age at first sex among AGYW interviewed was 16.6 years which was broken down as follows: 16.2 years for in-school and 16.8 years for out of school. Overall, most of the respondents had first time sex with either their boyfriend (80.4%) or husband (15.6%), with 2.4% of the in-school participants reporting to have had their sexual debut in marriage compared to 21.0% among out-of-school AGYW. Prevalence of HIV was higher in the out-of-school compared to the in-school participants (5.5% vs 2.0%), Similarly, the prevalence of syphilis was higher in the out-of-school than the in-school participants (4.1% vs 1.5%).
The study focused on assessing the prevalence and vulnerability of HIV, syphilis, GBV, and SRH services uptake among adolescent girls and young women, and exploring factors affecting girls' stay-in-school and re-engagement. The study found that HIV and syphilis are still significant public health problems among adolescent girls and young women in Zambia, emphasizing the need for increased efforts to prevent and manage these infections.
Journal Article
Antimicrobial resistance and heterogeneity of Neisseria gonorrhoeae isolated from patients attending sexually transmitted infection clinics in Lusaka, Zambia
by
Ngalamika, Owen
,
Maimbolwa, Margaret C.
,
Siame, Amon
in
Animal Genetics and Genomics
,
Antibiotics
,
Antimicrobial agents
2024
Background
Antimicrobial resistance (AMR) of
Neisseria gonorrhoeae
is a threat to public health as strains have developed resistance to antimicrobials available for the treatment of gonorrhea. Whole genome sequencing (WGS) can detect and predict antimicrobial resistance to enhance the control and prevention of gonorrhea. Data on the molecular epidemiology of
N. gonorrhoeae
is sparse in Zambia. This study aimed to determine the genetic diversity of
N. gonorrhoeae
isolated from patients attending sexually transmitted infection (STI) clinics in Lusaka, Zambia.
Methods
A cross-sectional study that sequenced 38
N. gonorrhoeae
isolated from 122 patients with gonorrhea from 2019 to 2020 was conducted. The AMR profiles were determined by the E-test, and the DNA was extracted using the NucliSens easyMaG magnetic device. Whole genome sequencing was performed on the Illumina NextSeq550 platform. The Bacterial analysis pipeline (BAP) that is readily available at:
https://cge.cbs.dtu.dk/services/CGEpipeline-1.1
was used for the identification of the species, assembling the genome, multi-locus sequence typing (MLST), detection of plasmids and AMR genes. Phylogeny by single nucleotide polymorphisms (SNPs) was determined with the CCphylo dataset.
Results
The most frequent STs with 18.4% of isolates each were ST
7363
, ST
1921
and ST
1582
, followed by ST
1583
(13%), novel ST
17026
(7.9%), ST
1588
(7.9%), ST
1596
(5.3%), ST
11181
(5.3%), ST
11750
(2.6/%) and ST
11241
(2.6%) among the 38 genotyped isolates. The
blaTeM-1B
and
tetM
(55%) was the most prevalent combination of AMR genes, followed by
blaTeM-1B
(18.4%),
tetM
(15.8%), and the combination of
blaTeM-1B
,
ermT
, and
tetL
was 2.6% of the isolates. The AMR phenotypes were predicted in ciprofloxacin, penicillin, tetracycline, azithromycin, and cefixime. The combination of mutations 23.7% was
gryA
(S91F),
parC
(E91G),
ponA
(L421) and
rpsJ
(V57M), followed by 18.4% in
gyrA
(S91F),
ponA
(L421P),
rpsJ
(V57M), and 18.4% in
gyrA
(D95G, S91F),
ponA
(L421P), and
rpsJ
(V57M). The combinations in
gyrA
(D95G, S91F) and rpsJ (V57M), and
gyrA
(D95G, S91F),
parC
(E91F),
ponA
(L421P) and
rpsJ
(V57M) were 13.2% each of the isolates. Plasmid
TEM-1
(84.2%),
tetM (
15.8%), and gonococcal genetic island (GGI) was detected in all isolates.
Conclusion
This study revealed remarkable heterogeneity of
N. gonorrhoeae
with
bla
TEM−1
,
tetM, ponA, gyrA
, and
parC
genes associated with high resistance to penicillin, tetracycline, and ciprofloxacin demanding revision of the standard treatment guidelines and improved antimicrobial stewardship in Zambia.
Journal Article